View Full Version : Bose 901 Response Graph


jindra
10-14-2011, 01:04 PM
It seems that the bose speakers everyone talks about are always the 901's. I wouldn't mind getting a pair for cheap, but also wouldn't mind knowing how flat the response is. I'm sure there is a whole bunch of people going to tell me how it doesn't matter about response curves and how you should go with what sounds good to you. I don't care to hear any of those opinions at all. First I read specs, then I listen if I like the sound, if I'm going to buy something. I'm after a response curve of the speakers and if they fall within 3db from let's say 40hz to 20Khz. It seems there is no such thing on this planet. Why would anyone ever spend over $1000 on brand new speakers that don't advertise their response?

If anyone has a response curve of these speakers or knows where to find one, I would appreciate the link!

rnorton
10-14-2011, 01:30 PM
It seems that the bose speakers everyone talks about are always the 901's. I wouldn't mind getting a pair for cheap, but also wouldn't mind knowing how flat the response is. I'm sure there is a whole bunch of people going to tell me how it doesn't matter about response curves and how you should go with what sounds good to you. I don't care to hear any of those opinions at all. First I read specs, then I listen if I like the sound, if I'm going to buy something. I'm after a response curve of the speakers and if they fall within 3db from let's say 40hz to 20Khz. It seems there is no such thing on this planet. Why would anyone ever spend over $1000 on brand new speakers that don't advertise their response?

If anyone has a response curve of these speakers or knows where to find one, I would appreciate the link!

Paul Klipsch once showed me the response curve that he had run on 901's (He carried about a hundred response charts around in his shirt pocket). It looked like a magnified view of a crosscut blade. I didn't see a flat octave in there anywhere. That's why Bose doesn't publish their response charts.

kconnor
10-14-2011, 01:30 PM
Bose doesn’t publish response curves because these are direct/reflecting speakers.
I recently read an old Stereo Review article that reported measured the response as 35Hz – 17kHz +/-5db on axis. They commented on how difficult it is to get accurate measurements by convention means because of the reflected sound. My experience with them was favorable, they held their own compared to a couple of other well reviewed Klipsch speakers I owned.

R-2-R
10-14-2011, 01:41 PM
Maybe this will answer some of your question, this was from another inquiry about the same subject from another forum and this is the response the individual received from Bose (if not you can always contact Bose and inquire specifically about frequency response)...............


Thank you for your inquiry. Bose (R) Corporation does not publish frequency responses, simply because they are not accurate and usually will mislead the customer.

Frequency responses are usually measured with testing equipment set up in an anechoic chamber. An anechoic chamber is an isolated room designed so that sound will not reflect off any surfaces. Giving out such frequency response results is terrific- for those people who live in anechoic chambers! Most of us listen to our systems in rooms with very reflective surfaces, such as plaster, brick, glass, and dry wall, so the frequency response that a manufacturer may supply is no longer accurate. Just as no two rooms have the same dimensions, nor are they decorated exactly the same or have the same construction, no two rooms will sound the same when using the exact same
speakers and amplifier.

For example, if you were to place any speaker in a room with no carpeting and wooden furniture, you would hear something completely different than if they were placed in a room with shag carpeting and plush furniture. Perhaps
this can be equated by imagining a single lighted candle placed in a room with completely black floors, walls and ceiling. Obviously, the same candle when placed in a room with white surroundings will appear to be emitting
much more light than when placed in the first room with black surroundings, as the light will reflect a great deal more off the white surfaces. Sound reflects off surfaces, much like light does. The surroundings make the speakers sound different in the same manner, because they actually are able to reproduce different frequencies via sound reflection and speaker placement.

We hope you do not take the fact that we do not publish speaker frequency responses personally. We do not publish our speakers specifications to anybody, whether it be before or after they have purchased a speaker system
of ours. We simply invite our customers to listen to our speakers using the most accurate testing equipment possible- their ears.

If we can be of additional assistance in the future, please contact us toll free at (800) 999-2673 extension EM1, or email us from our Bose website at:

http://www.bose.com/contact_us/

Jon_Logan
10-14-2011, 01:44 PM
If you get them, make sure you get the eq.

TerryO
10-14-2011, 01:45 PM
It seems that the bose speakers everyone talks about are always the 901's. I wouldn't mind getting a pair for cheap, but also wouldn't mind knowing how flat the response is. I'm sure there is a whole bunch of people going to tell me how it doesn't matter about response curves and how you should go with what sounds good to you. I don't care to hear any of those opinions at all. First I read specs, then I listen if I like the sound, if I'm going to buy something. I'm after a response curve of the speakers and if they fall within 3db from let's say 40hz to 20Khz. It seems there is no such thing on this planet. Why would anyone ever spend over $1000 on brand new speakers that don't advertise their response?

If anyone has a response curve of these speakers or knows where to find one, I would appreciate the link!

The 901 would be a tough one to measure for Frequency Response. Using an anechoic chamber, or a windowed signal, would probably give you an on-axis response which, I believe, is a rather dishonest measurement with the 901's.
Bose extolled the 8:1 reflected to direct ratio and this wouldn't be shown on the measurements. Any other type of measurement would be, in large part, a measurement of the room and not the speaker and is therefore not a valid measurement.

I imagine that the 901's real frequency response, in room, is pretty lousy, not unlike many speakers in a real world situation. IMHO, if you're looking for accuracy in your sound, you should skip the 901's altogether and move on to something else.

Best Regards,
TerryO

nclh77
10-14-2011, 02:37 PM
Don't hold your breath waiting to see one. Even Stereo Review did not publish a graph when they reviewed the V's in the late seventies with a comment regarding the validity of any possible measurement.

jindra
10-14-2011, 02:44 PM
At least if we had some kind of "expected response curve within the ideal room setup" for these speakers and I would be quite happy. At least something that I could compare to.

Are we supposed to be reflecting the speakers against a concrete wall or a wooden wall? How thick should that wall be? How would someone even go by setting these up since there isn't any ideal setup with a comparable response to go by?

There has to be some way to set them up to make a good sound stage where you could measure the flatness of the response. Otherwise what the hell are people listening to? Even if it would be mostly a measurement of the room, at least we would know of what they are capable in the most accommodated listening room.

I'm definitely going to steer clear of these unless they're below $100.

Putterman
10-14-2011, 03:07 PM
http://worldwide.bose.com/pro/en_us/assets/pdf/en/tds_panaray_802_series3_loudspeaker.pdf

This is the website of the datasheet for a BOSE speaker which is similar to the 901 in that it uses multiple 4 inch drivers, but definitely not the same in that they're essentially front radiating. The amount of info is staggering including directivity, impedance, and so forth. What they're essentially saying is don't worry your pretty little head about flat frequency response (if you're a consumer).

This is true of most speaker companies. I tend to buy from the ones that do give more info such as Boston Acoustics, Infinity and a handful of others. While the datasheet has more info than most people need, including me, I'd rather have that, than buying solely on reputation and word of mouth which is essentially where we are today in this age of the internet, many speaker brands and few audio stores.

jindra
10-14-2011, 03:26 PM
The response graph at the bottom is just awful. How can they say 60Hz-15KHz +/-3dB, but the graph shows more than +/5dB easily in that range. Not even going into how bad 15KHz is, considering I'm complaining my MG-IIc's don't go to 20Khz.

frankxbe
10-14-2011, 03:45 PM
One reason that the 901's worked best with an equalizer is lack of a flat response curve and the reflected sound . Having owned a set in the past I can say they can go very loud when you feed them a lot of power. Placement is critical the sound is not as
accurate as some other speakers . That being said they present at least to me and others an interesting sound field. It has been said "you either like or hate them "
They can certainly fill a room with sound. They were widely used in Disco`s and nightclubs at one time for that reason . None the less I found them interesting and not objectionable . There are tons of threads on AK and elsewhere on 901's .
regards

whoaru99
10-14-2011, 03:54 PM
Why would anyone ever spend over $1000 on brand new speakers that don't advertise their response?


Because they listened to them and liked the sound.

sealy
10-14-2011, 04:13 PM
One reason that the 901's worked best with an equalizer is lack of a flat response curve and the reflected sound . Having owned a set in the past I can say they can go very loud when you feed them a lot of power. Placement is critical the sound is not as
accurate as some other speakers . That being said they present at least to me and others an interesting sound field. It has been said "you either like or hate them "
They can certainly fill a room with sound. They were widely used in Disco`s and nightclubs at one time for that reason . None the less I found them interesting and not objectionable . There are tons of threads on AK and elsewhere on 901's .
regardsYes, they would make good disco speakers, since in such an environment, quantity of sound is more important than quality. With 9 drivers, I'm sure 901s can take all the power thrown their way.

Rick Vestal
10-14-2011, 04:37 PM
There's a reason they don't post the response...

jindra
10-14-2011, 05:19 PM
Because they listened to them and liked the sound.

I guess we are at the point of fidelity vs. personal opinion. I have run into instances where I prefer the lower quality/distorted version of a recording rather than it's lossless counterpart. Also listening to some things in my Toyota Corolla stock sound system provides a different experience, sometimes more enjoyable than my home speakers, maybe bringing back memories of my earlier days listening to crappy speakers.

What if Bose tried to make the 901 flat? Would the speaker be worse then? Does the whole science behind a reflected speaker depend on a massively inconsistent response curve?

The 901's are a bit intriguing, but spending the same amount on a pair of 901's as a pair of DQ-10's is absurd for me. Maybe I'll find them for a decent price and see what the fuss is about one day.

whoaru99
10-14-2011, 05:23 PM
There's a reason they don't post the response...

OK, but I think the point was made as to just what is the proper measurement on that type of speaker. I'm not defending the speaker or Bose, per se, but I do defend presenting data that's proper. Don't have the answer though on the best way to measure it.

Also note it was without EQ which could/should shore up the lows and the highs. Also, without a frame of reference of another speaker in the same (apparently) house, measured the same way, it's pretty hard to say what is speaker and what is room.

leesonic
10-14-2011, 05:28 PM
If you get them, make sure you get the eq.

Amen to that. I have a pair of 901s I'm restoring, but I don't have the EQ. So do I spend $150 more to find out whether they sound good or not?

Bose 901 restoration thread (http://www.audiokarma.org/forums/showthread.php?t=392040)

whoaru99
10-14-2011, 05:33 PM
Amen to that. I have a pair of 901s I'm restoring, but I don't have the EQ. So do I spend $150 more to find out whether they sound good or not?

Bose 901 restoration thread (http://www.audiokarma.org/forums/showthread.php?t=392040)


If you have a regular EQ, you might be able to get somewhat close enough to decide if you want to go all the way with the Bose EQ.

Here's what I approximated with a little but not too much tweaking. Not exact, but ballpark to some of the Bose EQ curves I've seen published.

http://www.audiokarma.org/forums/picture.php?albumid=143&pictureid=8401

http://www.audiokarma.org/forums/picture.php?albumid=143&pictureid=8402

Rick Vestal
10-14-2011, 07:22 PM
OK, but I think the point was made as to just what is the proper measurement on that type of speaker. I'm not defending the speaker or Bose, per se, but I do defend presenting data that's proper. Don't have the answer though on the best way to measure it.

Also note it was without EQ which could/should shore up the lows and the highs. Also, without a frame of reference of another speaker in the same (apparently) house, measured the same way, it's pretty hard to say what is speaker and what is room.

It was his backyard... I swear, I'm going to buy a set and see what the hype is... I REALLY want to hear a 6+ series...

Celt
10-14-2011, 07:52 PM
Amen to that. I have a pair of 901s I'm restoring, but I don't have the EQ. So do I spend $150 more to find out whether they sound good or not?

Bose 901 restoration thread (http://www.audiokarma.org/forums/showthread.php?t=392040)

You'll never have a clue as to what they should sound like without it. Be sure to get the Eq designed for the series of 901 you own.

R-2-R
10-14-2011, 08:51 PM
Basically it all comes down to a matter of opinion. Any manufacturer can put down all kind of sh#t on paper and make their product appear as if it is the ultimate in sound performance, some of it maybe true some not, keep in mind there just words on paper. Though, the truth of the matter is anyone can say whatever they want to make their speaker sound as if it is the very top of the line and thats where one's opinion comes in. But in reality the 'only way' one can actually determine this, in their opinion and judgement, is to actually listen and hear them for themselve's.
As for the 901's well these weren't designed to be used outside (earlier someone posted something about frequency response on the Bose 901 outside performance so that really is useless info.) they were strickly designed for indoor use. If you want outdoor use from a Bose speaker try the 802 speakers models (Series I, II & III) these are designed for outdoor use as well as indoors.
In my opinion there are three (3) things that are of importance to consider when hearing the 901's. 1) Proper placement 2.) matching the correct Active Equalizer Series for each particular Bose 901 Series used and 3.) using a good quality power amplifier to deliver that power, start off slowly then crank it up.
Like I mentioned in the beginning. This is all a matter of opinion on each individual so if you really want to find out, hear them for yourself and make your decision then.

wsissons
10-14-2011, 09:53 PM
I had a set of 901 series 2 for a short time thank goodness all but one of the drivers pointed away from me........honestly in my opinion a horrible speaker just not for me......But nice job restoring those though. It kind of reminds me when I was young I thought pussy cat wine tasted good........Its not west coast sound not east coast sound not English sound its a sound of its own I guess.....

bshorey
10-14-2011, 10:00 PM
There's a reason they don't post the response...

Well, that's not really a fair measurement.

Here is an aftermarket 901 driver from Parts Express:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-922

Freq response is listed as 83-15k hz. I'd allow a little lower for all the drivers, but generally speaking this should put you in the ballpark.

bs

Mmaxed
10-14-2011, 10:32 PM
At least if we had some kind of "expected response curve within the ideal room setup" for these speakers and I would be quite happy. At least something that I could compare to.

Are we supposed to be reflecting the speakers against a concrete wall or a wooden wall? How thick should that wall be? How would someone even go by setting these up since there isn't any ideal setup with a comparable response to go by?

There has to be some way to set them up to make a good sound stage where you could measure the flatness of the response. Otherwise what the hell are people listening to? Even if it would be mostly a measurement of the room, at least we would know of what they are capable in the most accommodated listening room.

I'm definitely going to steer clear of these unless they're below $100.

I have a pair of series II. While I can't answer your questions I will tell you that placement is critical. In my room a few inches can be the difference between total crap and way above average. Not only can positioning change the frequency response that you here but the imaging, sound stage, everything.

Do they lack highs? My kid thinks they do, but since my ability to hear anything above 12k is gone I don't notice.

Do they lack bass? Yes deep bass is not there, but fed right they will move enough air to move the drapes.

Are they picky about amps? Yep. M80 is a nasty match. A lowly HK680 sounds much better, but won't shake the walls.

Are they my favorite speaker? Nope. But give them the right amp and setup in the right room and they don't deserve the bashing they get.

TerryO
10-14-2011, 11:18 PM
Well, that's not really a fair measurement.

Here is an aftermarket 901 driver from Parts Express:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-922

Freq response is listed as 83-15k hz. I'd allow a little lower for all the drivers, but generally speaking this should put you in the ballpark.

bs

I certainly wouldn't buy those aftermarket drivers. I checked them out and here's PE's specs:

Specifications: • Power handling: 30 watts RMS/60 watts max • VCdia: 1" • Le: 0.11 mH • Impedance: 1 ohms • Re: 0.76 ohms • Frequency response: 83-15,000 Hz • Fs: 83 Hz • SPL: 91.5 dB 1W/1m • Vas: 0.24 cu. ft. • Qms: 2.41 • Qes: 0.43 • Qts: 0.36 • Xmax: 0 mm (full range driver) • Dimensions: Overall diameter: 5.20" (circle drawn around the three points), Cutout diameter: 4.02", Depth: 2.17".

It's obvious to me that it would be hard to have any dynamics from drivers with "0 mm" x-max!
OTOH, the blackness between the notes would be astounding!

Best Regards,
TerryO

rnorton
10-14-2011, 11:33 PM
At least if we had some kind of "expected response curve within the ideal room setup" for these speakers and I would be quite happy. At least something that I could compare to.

Are we supposed to be reflecting the speakers against a concrete wall or a wooden wall? How thick should that wall be? How would someone even go by setting these up since there isn't any ideal setup with a comparable response to go by?

There has to be some way to set them up to make a good sound stage where you could measure the flatness of the response. Otherwise what the hell are people listening to? Even if it would be mostly a measurement of the room, at least we would know of what they are capable in the most accommodated listening room.

I'm definitely going to steer clear of these unless they're below $100.

Klipsch did all of his curves outdoors in an L shaped corner of the factory.
My main objections to 901's is that they make narrow sound sources sound much too wide in the soundstage. A piccolo shouldn't sound 8 feet wide.

TerryO
10-14-2011, 11:51 PM
Klipsch did all of his curves outdoors in an L shaped corner of the factory.
My main objections to 901's is that they make narrow sound sources sound much too wide in the soundstage. A piccolo shouldn't sound 8 feet wide.

Or make a Bosendorfer sound like 96 feet wide.

A few people on the old Bass List used their's for parties. They'd turn them around 180 degrees and blast away.

Best Regards,
TerryO

GordonW
10-15-2011, 08:05 AM
Or make a Bosendorfer sound like 96 feet wide.

A few people on the old Bass List used their's for parties. They'd turn them around 180 degrees and blast away.

Best Regards,
TerryO

I have a feeling that so many people did this (turn them around 180 degrees and blast away), that someone at Bose said "hey, we could sell this as a PA speaker!"... and hence, the 800 and 802 were born! :D

Regards,
Gordon.

Hoho
10-16-2011, 07:38 PM
"I'm after a response curve of the speakers and if they fall within 3db from let's say 40hz to 20Khz. It seems there is no such thing on this planet."

From soundandvisionmag.com, written by Brent Butterworth:

"Here are two speakers with essentially flat frequency response: the Revel Salon2 and the Paradigm MilleniaOne. I havenít seen a less-than-glowing review of either one." The Paradigms are affordable.

Soundminded
10-16-2011, 08:57 PM
I can only talk about the original and series II which for all practical intents and purposes are identical. The only real difference between them is Series II offers more equalization curves which boost treble relative to what it calls flat and the original offers more curves which are cuts. Set flat the two are identical.

There is a misunderstanding about the bass response which Bose went into great detail explaining. These first two versions were acoustic suspension loudspeakers. Like all such speakers they have a linear falloff of 12 db per octave below system resonance. Bose claimed that phase shift associated with resonance was only audible up to 180 hz so he made the cabinet smaller to push the resonant frequency above 180 hz and applied a boost below that to compensate for the falloff. The problem as I see it is that the boost is only 6 db per octave. e/e magazine reviewed 901 and said it had a 7db peak at 250 hz which it claimed was inaudible. Mine sounds like it has about an 8 db peak at around 500 hz and it is very audible. Also deep bass is inadequate unless the system is played very loud. The falling LF response seems to equal the 1 khz output at around 90 hz in my room. The fix is to equalize out the peak and the falloff to compensate making the system flat. This creates even greater demands on amplifier power. My 138 wpc Marantz receiver can easily be overdriven in a small room like my 14 x 14 sun room where they're installed.

The other problem is at the high end. Bose 901 to my ears doesn't have one. I don't care what the measurements say, I don't hear the top octave. I agree with Gordon Holt who said the 4" drivers have too much inertial mass to produce HF. And even if it could, a 4" driver would respond only on axis at those frequencies. The reviews that mentioned HF rolloff as I recall said it began at 12 khz and was gone by 14. The fix for that is to add tweeters and turn the system into a 2 way biamplified system. But because of the difference in absorption of high frequencies and lower frequencies by the room boundaries, the system must have a rising output for its reflective components as frequency increases to compensate. When properly corrected (it took me 4 years to get it right) it can be made into an outstanding speaker system, more accurate at reproducing the sound of acoustic musical instruments in the room they're in than any other speaker I've ever heard. Of couse equalization to adjust for differences in each recording is also required. That is very tedious and can be frustrating. So it can be done. But I don't expect anyone who has ever heard Bose 901 as it is manufactured to believe it.

klama2006
10-17-2011, 02:13 AM
I have a set of series II, and they can sound just as good as any speaker I have collected from that time period.

Most speakers have flaws, and the 901 also have there share. They can also do somethings very well. In my concrete wall'd basement, I've never heard a better classical music speaker than the 901's.

Take it for whats it worth........ I have no agenda.

DaveElton
10-17-2011, 04:32 AM
I have a set of 901 series 6 with the EQ that I was able to pick up localy and cheaply hooked up in my Mom's living room. I honestly have no idea what a response graph on them would look like (I leave the Bose EQ set at "flat-midpoint) but in comparing them with other fav speakers I have on hand (NLA's, Cizek 1's, DCM Timewindow A's, KLH 6's) the highs and lows contained in the music I listen too are all "there" in realistic porportions (to my ears anyway) Placement of course plays a big factor with this speaker, and everyone's mileage may vary, but I enjoy listening to music from them:yes:

Soundminded
10-17-2011, 06:22 AM
I have a set of series II, and they can sound just as good as any speaker I have collected from that time period.

Most speakers have flaws, and the 901 also have there share. They can also do somethings very well. In my concrete wall'd basement, I've never heard a better classical music speaker than the 901's.

Take it for whats it worth........ I have no agenda.

A concrete wall is the best possible reflector for these speakers. They will reflect practically all of the sound at all frequencies that comes out of them. But most of us have walls made of more absorbent material such as 1/2 inch sheet rock on wooden 2x4 studs. The results are less than satisfactory for most. IMO the saying No highs, no lows, it's Bose has a certain degree of validity to it. Other speakers including some very expensive ones like the highly regarded Quad have similar limitations. In the current era where people prefer sizzle boom sound, Bose 901 usually disappoints even when it is correctly installed. I think for most audiophiles the lack of high frequencies is the most disappointing. I heard a pair of series VI three years ago at a Bose store in Newport Beach Ca and it had the same muffled high end every other series I heard has. I'm no Bose basher, I've owne my pair for over 40 years. I just judge them for what they are without any illusions or preconceptions. BTW, the original and series II systems using CTS drivers remained in perfect condition all these years. All I had to do was reseal the cabinets. I used GE clear silicone caulking where the metal frames joins the cabinet and on the screw heads. I was careful not to get any on the suspensions.

Hoho
10-17-2011, 10:28 AM
Here are two response graphs for the 901 Series VI system, from The $ensible Sound magazine, Feb/Mar 2003, and from Digital Audio magazine, Apr 1988.

kconnor
10-17-2011, 10:49 AM
in comparing them with other fav speakers I have on hand (NLA's, Cizek 1's, DCM Timewindow A's, KLH 6's) the highs and lows contained in the music I listen too are all "there" in realistic porportions (to my ears anyway)

My experience with the 901 VI was much the same. They compared well against my Klipsch KG4 and Forte 1. Actually in my room the 901 produced deeper bass than either of them while giving up nothing on the high end. I bought the Bose mainly out of curiosity and I was impressed with them. I no longer own them.

The response graphs Hoho posted look very ragged and Bose bashers will no doubt point at them as evidence to bolster their position. In actuality, in-room and ungated curves of a high quality direct radiating system will look as ragged as these are.

Hoho
10-17-2011, 11:38 AM
The response graphs Hoho posted look very ragged Ö .

Actually, the graph from The $ensible Sound is fairly smooth: +5/-4 db from 31.5 Hz to 12.5 Khz, with only five humps in between. More than four or five peaks can be considered spiky. But the OP was hoping for better.

jindra
10-17-2011, 11:43 AM
My main problem with bose is the lack of relevant information to the speakers. It should be listed in the instructions what is the perfect setup for them, what kind of wall to reflect from, since the wall plays such a huge part of how these speakers will sound, they must have had some kind of ideal setup in mind. Hopefully those response graphs were done with reflected sound, not direct and outside somewhere. It's a shame that bose doesn't publish this, since it's left up to others to test with likely a different setup than bose's ideal setup. The 801's don't look too bad, but such better things can be had for the same price range imo.

I really shouldn't be, but I'm stuck comparing these to the DQ-10's, which go 37-27k +/-3db. Maybe I got a really good deal on the DQ's but it seems the Bose 901's and the DQ-10's are in a similar price range and it doesn't make sense to me.

Hoho
10-17-2011, 11:43 AM
Here are two graphs for the Bose 601. One is for the Series II, from Audio magazine, ca. 1982. The other is for the Series III, in Digital Audio magazine, in Jan. 1987. Different models, different magazines, different years, but the measurements are almost the same. This demonstrates that measurements from direct/reflecting speakers don't necessarily have to be inconsistent.

Hoho
10-17-2011, 11:57 AM
My main problem with bose is the lack of relevant information to the speakers. It should be listed in the instructions what is the perfect setup for them, what kind of wall to reflect from, since the wall plays such a huge part of how these speakers will sound, they must have had some kind of ideal setup in mind. Hopefully those response graphs were done with reflected sound, not direct and outside somewhere. It's a shame that bose doesn't publish this, since it's left up to others to test with likely a different setup than bose's ideal setup.

The booklet does include guidelines for installation. The Series VI EQ was designed for what Bose considers to be the average room, not the ideal room.

Amar Bose, billionaire, is said to have built his home with no parallel walls, for perfect acoustics. But I can't do that. Can you?

The T$S test was conducted moving the mike around the listening area. The speakers were farther from the walls than Bose recommends. However, I believe that the people at Bose Corp. wouldn't object, because the room was larger than average.

The caption under the 901 graph from Digital Audio does explain how it was measured, and says that the measurements are difficult to interpret.

jindra
10-17-2011, 12:10 PM
I think ive gotten the information i wanted. I might be overthinking this and Im probably mistaken that they are around the same value as dq-10's. If the price is right i might still try them out.

whoaru99
10-17-2011, 12:32 PM
I really shouldn't be, but I'm stuck comparing these to the DQ-10's, which go 37-27k +/-3db. Maybe I got a really good deal on the DQ's but it seems the Bose 901's and the DQ-10's are in a similar price range and it doesn't make sense to me.

I'm sure you know it, but bear in mind the +/-3dB published for the DQs is almost certainly anechoic response. Placed in a room, they may fare no better in response curve appearance than the Bose do. And, also how much smoothing and other factors are applied to the graph and measurements.

There's a smoothed and not smoothed curve for some speakers I have, rated 39Hz-22kHz, +/-2dB, anechoic, tested with a sweep measurement using REW. Note I believe there is a sub playing on the low end in this sweep, but I don't recall for sure.

jindra
10-17-2011, 12:36 PM
I'm sure you know it, but bear in mind the +/-3dB published for the DQs is almost certainly anechoic response. Placed in a room, they may fare no better in response curve appearance than the Bose do.

Absolutely, I just like knowing that they are at least capable of such a response given the ideal circumstances.

TerryO
10-17-2011, 12:47 PM
Absolutely, I just like knowing that they are at least capable of such a response given the ideal circumstances.

I don't believe that an anechoic chamber would necessarily qualify as ideal circumstances, at least for listening. But I understand what you mean.


Best Regards,
TerryO

Copa1934
10-17-2011, 05:39 PM
It seems that the bose speakers everyone talks about are always the 901's. I wouldn't mind getting a pair for cheap, but also wouldn't mind knowing how flat the response is. I'm sure there is a whole bunch of people going to tell me how it doesn't matter about response curves and how you should go with what sounds good to you. I don't care to hear any of those opinions at all. First I read specs, then I listen if I like the sound, if I'm going to buy something. I'm after a response curve of the speakers and if they fall within 3db from let's say 40hz to 20Khz. It seems there is no such thing on this planet. Why would anyone ever spend over $1000 on brand new speakers that don't advertise their response?

If anyone has a response curve of these speakers or knows where to find one, I would appreciate the link!
I find the whole reference to anechoic chamber measurements a bit ridiculous. The whole point of an anechoic chamber is the practical elimination of "reflected" sound. How in the devil do you get a respective measurement from a speaker that is solely dependent ON reflected sound, short of multiple mikes? And in doing so, how is that a fair comparison to other speakers? It's not.

I can't possibly think of any better way to compare than to have proper, not necessarily ideal or perfect, room arrangements for whatever speakers you are listening to. My allison cd7's are finicky, much like though not as much so, as 901's. In the very same room I had to change placement many times before finding an ideal position. As luck would have it, that didn't suit my seating or the arrangement of my equipment. That wasn't good as I did like the final sound, but I'm not about to change my entire room to accommodate speakers. Room aesthetics prevail, oh well.

Room acoustics, probably, play the most significant role in our enjoyment of our equipment. Sadly too many people simply claim it's the speakers and be done with it. I honestly believe what is best for me is something that sounds good to my ears, using the equipment I presently own and don't require great efforts in room reorganization. Especially where my wife is concerned. 30+ years I'm not going to screw up over speakers.

jindra
10-17-2011, 11:19 PM
I've been playing with speaker placement for the last several months or even a year with the DQ-10's and MG-IIc's. I've gone through so many different positions with the speakers. I might have finally found something I like, around 7 or 8 feet for the DQ-10's and 15-16 feet for the MG-IIc's. I still haven't treated the room in any way really since I'm still searching for the ideal placement of all these.

I don't really take room acoustics into account when I'm shopping for speakers. My mentality is if the response is good, then I know it will only be the fault of the room acoustics/positioning if they sound bad, which personally I don't mind changing. As long as I'm not noticing limitations of the speakers, I'm happy. I have yet to go the full extent of treating a room acoustically, which might be on the to do list soon.

Soundminded
10-18-2011, 06:00 AM
I don't believe that an anechoic chamber would necessarily qualify as ideal circumstances, at least for listening. But I understand what you mean.


Best Regards,
TerryO

IMO an anechoic chamber is a horrible place to be in and the worst possible place to listen to music. However, it is useful for testing sound output of loudspeakers and other devices (such as noise generated by machines) free of external interferences such as room reflections and external noise.

There are at least two problems with anechioic chamber measurements. First they are generally incomplete. To fully test something you have to examine the total energy output which means the FR in every direction in space, not just at one or a few angles from it. The second problem is correlating anechoic measurements with performance in real rooms. Without the data due to the first deficiency correlating it to real world performance isn't possible. And without a solid mathematical model even if the data were available there's be no way to make sense of it. Since no such model esixts yet owing to the still primitive state of acoustic science, anechoic measurement data is of limited value even for so called experts. In the land of the blind the one eyed man is king.

Mmaxed
10-18-2011, 10:45 AM
I've been playing with speaker placement for the last several months or even a year with the DQ-10's and MG-IIc's. I've gone through so many different positions with the speakers. I might have finally found something I like, around 7 or 8 feet for the DQ-10's and 15-16 feet for the MG-IIc's. I still haven't treated the room in any way really since I'm still searching for the ideal placement of all these.

I don't really take room acoustics into account when I'm shopping for speakers. My mentality is if the response is good, then I know it will only be the fault of the room acoustics/positioning if they sound bad, which personally I don't mind changing. As long as I'm not noticing limitations of the speakers, I'm happy. I have yet to go the full extent of treating a room acoustically, which might be on the to do list soon.

I know what you mean about the room and placement. I owned a pair of MG-IIb's for most of 30 years. Could not make them sound better than OK in my current room. With the 901 II's it took some work but when positioned correctly sounded very good. Your results may vary.

jindra
10-18-2011, 11:00 AM
I know what you mean about the room and placement. I owned a pair of MG-IIb's for most of 30 years. Could not make them sound better than OK in my current room. With the 901 II's it took some work but when positioned correctly sounded very good. Your results may vary.

The magnepans are easily to most difficult to position. The DQ-10's I can at least somewhat enjoy without nit picking the placement too much, but the MG-IIc literally hurt my ears and frustrate me in the wrong spot.

klama2006
10-23-2011, 03:33 PM
I think the room placement of speakers is one of the most important factors in the enjoyment of a tuned system.

kconnor
10-24-2011, 04:13 PM
Here are two response graphs for the 901 Series VI system, from The $ensible Sound magazine, Feb/Mar 2003, and from Digital Audio magazine, Apr 1988.

For comparison to the Bose 901 curve posted earlier in the thread Iíve attached a curve I ran across for an AR3a. Seems speaker design has come a long way since the 60ís and Ď70ís. A Polk RTi28 tested in the same fashion as the AR speaker was notably superior in smoothness from 100Hz upward looking like a flat line in contrast.

johnjacob
10-31-2011, 04:35 PM
I completely agree about the personal Opinion, I have found the best speaker is truly the one's you like the most, i also sold 901's from the old model 901 to the 901 series 3 they made it more efficient and improved the electronics in the EQ, we used to run Parametric Eq's with the 901 to alter the sound in the room, allot of people loved them Spacial and kinda punchy. I sold them never owned any set up allot of systems (cause most people got all messed up on the hook up of the active Eq you HAD to use.) I prefer my Dq10 to them but I also own a set of EPI 602's and they are like a 901 sound but deeper bass and spacial sound again have actually run them with the DQ10's for some interesting Results.
Music reproduction is subjective. always has been always will.

hopeless
03-16-2012, 08:52 PM
I don't try to make it a huge secret that I'm no fan of Bose speakers. Not because Amar wasn't capable of designing good speakers, he certainly has the capabilities to do so, but that he instead focused on marketing over product. I am not a Bose "hater", I see myself as rather pragmatic about the whole thing. They are there, they perform within their limitations, and many people enjoy listening to them. Cool for them, I'm just not one of them. That said, the reliance of FR charts to determine speaker quality is a bit of a sham. While FR charts are great to figure out where a speaker has issues, they don't convey the tonality of the speaker or many other things that are very important.

I remember a night with a friend who had some Klipsch speakers and a pair of Klipsch pro bass bins driven by a pair of tube amps. I brought over an RTA and we set about trying to tune his system to his room. In the end, we laughed our asses off. While the system sounded pretty good, the readout from the RTA was atrocious, looking more like a sawblade than a speaker response. However, the tonality was actually pretty respectable and the system was very enjoyable. I did the same thing a few months later with a friends hombrew speakers and although they measured much better, the tonality was way off. RTAs measure energy over octaves, not accuracy in tonal reproduction.

Tonality is where most Bose speakers really blow it. With either no tweeters or paper tweeters which have poor dispersion characteristics into the room, the speakers are already at a distinct disadvantage. Bose is correct when they say, indirectly, that you can't separate the room from the speaker. However, that being said, you can't use that as an excuse for not properly engineering a speaker. Since the late 70s, using paper cone tweeters really hasn't been socially acceptable in engineering circles. Using multiple paper cone tweeters to make up for the lack of dispersion, again, is not an acceptable engineering adaptation. However, it is a great differentiation ploy for marketing.

The 901 is the most successful failure in the audio industry. As a speaker at it's price point, it was a technological failure. As a platform for launching a speaker company, it was a complete success. The success was in differentiation, not in performance. The 901, given power, can play loud and will sound huge. Where they fail is in any form of accurate presentation in scale or tonality. They don't perform well at frequency extremes, are very colored through the presence and midbass areas, and lack dynamics. This isn't to say that they can't be pleasant to listen to. On the contrary, they have largely been designed to be somewhat pleasant, as has the rest of the line. The reason Bose speakers sell is that they DON'T perform very well. It's their inaccuracy that provides their appeal. They will make a bad recording sound acceptable, especially if you are not a person interested in imaging, tonality, or accurate soundstaging, as most people aren't.

using nine 4 1/2" drivers is a massive compromise in frequency response, especially highs and lows. Using an equalizer to get those drivers to go where they don't want to go can only be partially effective. There are physical limits to such actions, and the dispersion characteristics of such drivers over 500 Hz or so is not going to be stellar, and using 8 of them to fire off the back wall introduces more problems into the chain.

I mentioned before that it's not possible to remove the room from the performance of any speaker. However, introducing MORE room interaction is asking for more problems. Where a bipole will equalize energy from front to back, a 901 throws 8/9ths of it's energy into the room and only 1/9th of it's energy at the listener. This unequal loading creates many issues and adds a different dynamic to tuning issues. Where the logical ideal of a speaker system that is trying to include the room into the mix would be to create a dispersion pattern that would attempt to load the room equally over a, for simplicities sake, a 360 degree pattern from the speaker. (Actually, spherical would be more accurate but I'm trying to keep the discussion simple here.) In this attempt, the 901 fails, making it more placement sensitive, and subjecting the rear output, 8/9ths of it, to the tonal shifts of the room it's in. This means that it will sound dramatically different in sheetrock rooms than concrete, paneled vs softer, etc. A situation that guarantees a larger chance of failure than success.

The 901s have more drawbacks than attributes. Again, this isn't to say that they can't be a pleasant listen, but they just haven't been engineered to eliminate the drawbacks, they have been engineered with the drawbacks as functionally integral to the speaker.

sheltie dave
03-16-2012, 09:00 PM
There is absolutely no reason you could not measure the response curve of a Bose 901, as they are nine IDENTICAL drivers in a ported cabinet. Anyone who can not wrap their head around this problem must believe Bose engineers are the best in the world.

If Paul Klipsch had no problem figuring out how to make an aneochic chamber work for Klipschorn measurements, surely the MIT edumaedicated Dr. Bose could do the same.

BTW, here is the equalization curves from a Bose 901 brochure.. it isn't too hard to overlay them with Rick's openfield measurements and have a lightbulb go on.
http://i232.photobucket.com/albums/ee209/sheltiedavid/boseblowsjpg.gif

http://i232.photobucket.com/albums/ee209/sheltiedavid/eqbose901.jpg

Please note Rick"s Series I is an accoustic suspension, while the IV is ported, but you can readily get the idea a midrange is a midrange, no matter the stripes...
http://i232.photobucket.com/albums/ee209/sheltiedavid/901noeq18fromwallmp6.gif

Copa1934
03-16-2012, 11:35 PM
There is absolutely no reason you could not measure the response curve of a Bose 901, as they are nine IDENTICAL drivers in a ported cabinet. Anyone who can not wrap their head around this problem must believe Bose engineers are the best in the world.

If Paul Klipsch had no problem figuring out how to make an aneochic chamber work for Klipschorn measurements, surely the MIT edumaedicated Dr. Bose could do the same.

BTW, here is the equalization curves from a Bose 901 brochure.. it isn't too hard to overlay them with Rick's openfield measurements and have a lightbulb go on.
http://i232.photobucket.com/albums/ee209/sheltiedavid/boseblowsjpg.gif

http://i232.photobucket.com/albums/ee209/sheltiedavid/eqbose901.jpg

Please note Rick"s Series I is an accoustic suspension, while the IV is ported, but you can readily get the idea a midrange is a midrange, no matter the stripes...
http://i232.photobucket.com/albums/ee209/sheltiedavid/901noeq18fromwallmp6.gif
Please forgive me as maybe I overlooked something prior in this thread, but, I don't think many people have difficulty wrapping their head around the whole response curve thing. The issue here is that the 8 drivers you're measuring are supposed to be rear facing and reflecting from walls. As an example, measuring a front facing Left Channel Main speaker says nothing when it's part of a surround system. Here you've only proven the obvious, you can measure the "on axis" and presumably off axis response of the 901.

I say take measurements, from a seated/listening position of both 901's and your favorite "pair" of speakers and overlay the results. Anechoic measurements are supposed to be a neutral measurement by which you can distinguish the "personalities" of speakers, essentially using the same measuring stick. We know that this methodology is NOT implemented in the most consistent manner among all companies. Nor is info published in the same manner, some charts are compressed or expanded to accentuate specific characteristics.

This by no means is shooting you down, just what exactly is the relevance since these speakers are not "aimed" at the listener in the same manner as traditional speakers? I don't think anyone doubts the obvious, that 901's excel in mid response, though I'd argue they begin to fall short below mid bass and fall off midway into the high end. Going by your chart, well outside "mid only" performance. Not many mids dip below 500hz nor play well above 4-5khz. These are playing comfortably down to 100hz and up to nearly 10khz. Hardly a "midrange" only speaker. Full range? Not without considerable assistance from EQ.

By the way, any thoughts on the jagged response curve? That is sick, just all over the place. Can't believe that the sum of 8 drivers will be that "all over the place" in response.

sheltie dave
03-17-2012, 06:45 AM
Please forgive me as maybe I overlooked something prior in this thread, but, I don't think many people have difficulty wrapping their head around the whole response curve thing. The issue here is that the 8 drivers you're measuring are supposed to be rear facing and reflecting from walls. As an example, measuring a front facing Left Channel Main speaker says nothing when it's part of a surround system. Here you've only proven the obvious, you can measure the "on axis" and presumably off axis response of the 901.Copa, two of the three sets of statics that Rick captured, the red and yellow graphs, are rear facing, with one reflecting from a boundary wall.
We also are measuring Bose 901s, so who cares about measuring a red herring surround system.

I say take measurements, from a seated/listening position of both 901's and your favorite "pair" of speakers and overlay the results. Anechoic measurements are supposed to be a neutral measurement by which you can distinguish the "personalities" of speakers, essentially using the same measuring stick. We know that this methodology is NOT implemented in the most consistent manner among all companies. Nor is info published in the same manner, some charts are compressed or expanded to accentuate specific characteristics.An aneochic chart shows a snapshot of speaker performance in a dead air space free of any environmental feedback, which allows the manufacturer to ascertain flaws in driver, crossover, and enclosure design and implementation. Taken in this manner, the only marketing involved is what smoothing equation, if any, is used to remove the grossest peaks and valleys. For Rick's readings, I'm sure he either used no sum of least squares, or his normal smoothing third order(and I doubt this.) His charts show a nice comb filtering distortion process across the board.

This by no means is shooting you down, just what exactly is the relevance since these speakers are not "aimed" at the listener in the same manner as traditional speakers?Please visit the read and yellow readings again. I don't think anyone doubts the obvious, that 901's excel in mid response, though I'd argue they begin to fall short below mid bass and fall off midway into the high end. Going by your chart, well outside "mid only" performance. Not many mids dip below 500hz nor play well above 4-5khz. These are playing comfortably down to 100hz and up to nearly 10khz. Hardly a "midrange" only speaker. Full range? Not without considerable assistance from EQ.Please take a look at the inflection shoulders on the least equalized graph line before you aver they comfortable play from 100Hz to nearly 10kHz. While they have significant energy for extended range, I use comfortable for a mid speaker in the region where they play =/- 1dB from low to high shoulder.

By the way, any thoughts on the jagged response curve? That is sick, just all over the place. Can't believe that the sum of 8 drivers will be that "all over the place" in response.Again, you are going to see some significant nodes and nulls from pronounced comb filtering, and that also is the nature of measurement data when you capture a very finite number of data points per octave. The goal is to take just enough data to get a good handle on anomolies, not to make a beautiful plot to sell more speakers.

When you see ten to fifteen dB variations in a 3-6 datapoints per octave graph, most companies will be going back to the drawing board. Bose knew this, hence they mainly declined to publish the relevant charts, except at the back end with the equalization curves like I posted.

Bose knew what he needed, and he purpose selected a mid that was rugged and had a stiff, heavier cone with a pronounced low end bump. He sought to build a speaker that would play loud and fit in a smaller room, and (like Klipsch) he went for low cost and minimal engineering. He certainly hit an economic home run, as I would say the Bose 901 is the best example of marketing and market pentration being maximized in the history of stereo here in the US.