Any Infinity QLS owners here?

[RussinOhio]

...Or, have any members at least heard the Quantum Line Source?
I remember reading about these big expensive Infinity speakers back in the late 70's. I remember reading the ads: "Watkins dual-drive woofer" comes to mind. I believe these speakers required tremendous amp power....if I remember correctly....each woofer needing(having?) its own amp.

Anyone remember these beast well? First time I saw them on the back cover of Stereo Review magazine I just stared & said: Wow.
Wonder if they live up to the "hype-of-the-day", back then. Now these are speakers I'd love to hear someday. I'm not looking for these....just thinkin 'bout the old days is all and I don't hear much talk about the QLS anymore.

Certainly someone here has heard them before. If anyone has a review that they could post, that'd be cool to read!!



Cheers,
Russ

[clifselina]

Here is what I found...
http://www.bobbyshred.com/infinity/QLS.html

[Charivari]

Yep, I’ve heard of them, but sadly have not heard them. As near as I can figure, those who have these speakers have nothing but praise for them, but as information is scattered, there must not be many out there.

Now, if the little brother of the QLS-1 counts, the Quantum 2 (now listed on the Infinity company website as the QLS-2), then yes and no. The Quantum 2 is essentially the same design; only the cabinet is a little shorter and there are only 4 EMIT tweeters and 2 dome midranges per speaker, versus the 9 and 6 respectively for the QLS-1. I have a pair of Quantum 2 speakers that I picked up over a year ago, but have yet to hear what they sound like do the midrange tinsels being broken (and beyond my abilities to solder thanks to some sort of coating on the wires [I’d appreciate any help in regards to this]). All I can vouch for with them is that the EMITs alone sound mighty nice and that the Watkins woofer in its sealed design is very tight and fast for what it is. In fact, I’m using these speakers as stereo subwoofers for my Magnepan MG-Is and feel that they can keep up with the planar sound fairly well. (Yes, my apartment is very, very full of speakers and audio goodies; I blame Goodwill for it.)

The Infinity Company that made these speakers is still around, though producing, imho, inferior products. Fortunately, they do have some very limited information regarding their previous offerings including the Quantum line. Their page (http://www.infinitysystems.com/homeaudio/product_support.aspx?ProdId=QLS1&Submit=Submit) concerning the QLS-1 states the power requirements of at least 100 watts per channel up to 500.

Now, just running the Watkins drivers on mine, I can vouch for how power hungry these are. When I first ran them to test my refoaming skills, they killed a Pioneer VSX-3300 I had scrounged up at low levels, as well as some supposedly 120 wpc ‘80s Technics receiver. I’m now running around 200 wpc and still having troubles driving those Watkins, but it is worth it. (I did briefly try these on a Pioneer SX-838 at low volumes and the bass was incredible.)

For further information, there are at least a couple of QLS-1 owners over on the fairly active Infinity Classics Yahoo Group that seem moderately talkative and most likely would be willing to share their opinions upon their speaker. You can find this group here (http://launch.groups.yahoo.com/group/InfinityClassics/):

If you’re curious, you can find the brochure for these speakers at Bobby Shred’s page (http://www.bobbyshred.com/infinity/QLS.html).

Now, as to your request for reviews, there’s the Infinity-Classics page (http://www.infinity-classics.de/infinity/index.htm) that used to have the manual for and reviews of the QLS-1. However, those seem to have gone missing, as near as I can tell not being able to read German and all. I did save the 2 page Stereo Magazine review from an earlier visit and will post it for your viewing pleasure.

My writing skills seem to be severely lacking this evening, so my apologies if I’m not too clear in what I’m trying to say.

- JP

Edit: Drat, clifselina posted Bobby Shred's link while I was typing up my overly long response. I better be quicker next time.

[Negotiableterms]

I have a set of QLSs that I bought about six months ago. I think the amp problem is that the Watkins woofer dips down to about 2 ohms, which sucks power. I'm not using them day-to-day, but when I first got them I hooked them up to an MC-2105, which seemed to struggle a little, then an MC-602, using the 4-ohm taps, and it worked well. To me, they sounded good, with a wide soundstage and great detail in the mid and treble. Bass was a little off, but I think the woofers are almost shot. I have a pet peeve about vertical dispersion: I hate it when the sound changes drastically between standing and sitting, so I'm drawn to line sources, which is why I bought these.

I'm trying to find someplace to restore them, and they need a lot of work. Anyone have recommendations (preferably near Lake Tahoe as they weigh a ton)?

[Charivari]

Alright, I've had to mutilate these scans to fit in under the attachment size and orientation limitations, but hopefully they're still legible.

Review taken from Infinity Classics (http://www.infinity-classics.de/infinity/index.htm)

- JP

[Charivari]

Negotiableterms,

they weigh a ton

Haha, while they don't technically weight a ton, they sure feel like it. I remember carrying my Q2s (lighter at ~140 lbs each) out of Goodwill and to my truck. I couldn't figure out why I was tired and was surprised at my seemingly being out of shape. I was thinking, "They can't be that heavy." I probably would not have carried them had I known their weight before buying them.

- JP

[rstsgsas]

I have 2 sets Of the Quantum 3s .I do not know how they compare to the QLS but these speakers are the only ones I have ever heard that will be with me till one of us is beyond repair ,shoot I might be buried in one.I really love the sound of them.1 set is driven by a 350 watts @4 ohm Soundcraftsmen Ma5002 amp and the other set I modified for biamping with 1 Ma5002 amp driving the woofers and anything from a Yamaha ca-2010 amp to a pioneer sx-1250 driving the rest.Its all sweet to my ears.

[Negotiableterms]

Does anyone have any suggestions for a restoration shop for a pair of QLSs? Thnaks!

[gonzothegreat]

I have a pair of Quantum 2 speakers that I picked up over a year ago, but have yet to hear what they sound like do the midrange tinsels being broken (and beyond my abilities to solder thanks to some sort of coating on the wires [I’d appreciate any help in regards to this]).

I resoldered the broken tweeter leads on a cheap pair of Technics 3 ways by removing the insulating layer on the wire. Either sandpaper or a couple passes with a razor blade over the wire. Support the lead with your finger while doing this or you'll risk snapping the wire.

Once there is good copper to solder to, you'll probably be set unless the break shortened the lead significantly. I had to splice a short length on my cheap tweeter. Hopefully you won't.

It took me six tries to get it right so you probably want to practice on something expendable before tackling the Qs.

[Negotiableterms]

I'm actually hunting for a speaker restoration shop to work on three pairs of speakers: the QLSs, a pair of Kappa 9s that badly need refoaming, and a pair of ESS AMT-3s that need all kinds of work. Anyone have any experience with professional restorers?

[gonzothegreat]

Negotiableterms - what do you mean by restoring? If its just driver work (reconing or refoaming) then try either of these places. You might want to send the drivers out to have repaired and then have any cabinet work done locally.

http://www.speakerrepair.com/
http://www.simplyspeakers.com/

Of course our resident speaker guru GordonW does great work too (including my SB7070 woofers that somebody had kicked in) but Orange County (www.speakerrepair.com) is closer to you. I believe they are an authorized Infinity repair center too. For the ESS you might want to directly contact the company if you need new diaphragms.

[Negotiableterms]

Gonzo- Thanks, I'll look into all three of those. By "restoring" I'm hoping to find a place that can re-foam/re-cone along with testing the internal wiring and crossover. After this many years, all of the crossover caps and some other components probably need replacing. At this age, the grilles need work to fit correctly, the grille cloths need replacing and the cabinets need re-finishing. If you send them to a furniture refinisher, the cabinets look great but the drivers have random drops of stain applied and the new grill cloth is acoustically opaque (painful experience). I've tried re-foaming on my own, and while it wasn't awful, the sound wasn't quite what I remembered, and I wound up buying replacement woofers, which sounded correct. I guess this has something to do with being a newbie at re-foaming, just like I am at AK.

[jim_arndt]

I've heard them, every Sunday morning at 7:30am my dad would wake me up as he read the paper listening to his QLS's. I feel guilty, because I boxed these up and stored them under my moms house about 10 years ago (my dad passed away in 86, he's probably rolling over in his grave thinking about his speakers.) Researching the net, now I'm starting to realize the sin I committed burying these fine speakers for so many years. I'm going to unpack them and take a look, hopefully they are still in decent condition.
My dad powered them with a single Dynaco 416. I remember in High School (when my dad was a work...) I used to suck the amp dry powering the Watkins subwoofer. I played around with hooking up a Phase Linear 400 amp and the Dynaco, one powering the woofers and the other the mid and highend, sounded pretty good but I'm no audiophile (especially back then.)

Anyone have any ideas what would be good current day amps to power these speakers?

[Negotiableterms]

Anyone have any ideas what would be good current day amps to power these speakers?

IIRC (and someone correct me if I'm wrong) your major job is to find an amp that tolerates really low impedence loads, as that Watkins woofer takes them down to less than 2 ohms at some frequencies.

Obviously, any of the current crop of "true voltage source" amps will do the trick, but cost a fortune. On the used front, try a PS Audio 200CX. Make sure it's a CX, though, the C wasn't as stable. Even better (and much more expensive), current new or used, try any of the McIntosh big-watt autoformer amps with 2 ohm taps. Ummm... I think MC-2255 on up, but I'm not sure, so check Roger Russel's site to be certain. I think you need at least 200 watts @ 8 ohms, with 2 ohm taps. Current models, an MC-252 is minimum, but an MC-402 should make them sing. Recent past, an MC-352 would be almost as good.

The other guys here may have better ideas, but if they're in good shape, you've got a pair of classic, collectable speakers that sound great!

[Charivari]

Jim Arndt, Welcome to AudioKarma!

I'm an owner of a pair of Quantum 2s, the little brother to your QLSs and would love to have the bigguns some day. They're definitely great speakers and will require a rare amplifier considering, as Negotiable Terms mentioned, that they dip down into the sub-2 ohm regions and are only 81 dB/1 watt/1 meter efficient.

I've been recently looking for information concerning a pair of Infinity electrostatic headphones and encountered a former Infinity salesman over at AA. He mentioned the QLS and made some mention of amplifiers to drive them; I've reproduced it for you below.

Our best Infinitys were the Servo Statiks (when they were working and we weren't replacing the electrostatic drivers). Another good Infinity we sold were the original QLS (Quantum Line Source) speakers with the Watkins woofers, but few amps would drive them well. The original QLSs were big, requied a very large room, and used a line array of tweeters. They later morphed this speaker down to several smaller sizes and changed the tweeters from domes to their EMIT tweeter they developed.

We found that Mark Levinsons and Ampzillas worked well. Interestingly, we took in a mint McIntosh MC2505 on trade (we weren't the McIntosh dealer iin town) that would barely drive them no matter which output taps we used, and it was one of the few times I heard a McIntosh amp sound terrible - It was not a good match for the QLS, but then it was only a 50 wpc amp and Infinity recommended at least 100 wpc for the QLSs. The Infinity Class D switching amp also would do a great job on the QLSs before the amp imploded.

As to fixing them up, you've come to the right place. The Watkins woofers should be an easy fix for you, its a given the foam surrounds will be shot by now, and most around here can help you out on that or you can have the original designer (http://www.watkinsstereo.com/) do the repairs. The midrange domes, if they've broken those all to fragile tinsels while in storage, can be repaired. If the EMITs may have gone bad, AK mod Army knows someone who can fix those for you.

Oh yeah, if at all possible, pictures would be nice.
- JP

[Negotiableterms]

Charivari-

Thanks for the Watkins site!!! I had no idea.

Now, the bad news is what it's going to cost to ship those two behemoths across the whole country. Yeech.

Thanks again!

[Charivari]

Charivari-

Thanks for the Watkins site!!! I had no idea.

Now, the bad news is what it's going to cost to ship those two behemoths across the whole country. Yeech.

Thanks again!
No prob. You've still a pair, right? What needs to be done with them? If you just need the Watkins woofers fixed up, you can send just them. For the rest, Orange County Speaker Repair (http://www.speakerrepair.com/) is commonly recommended for fixing up the older Infinities. Or ... you could always send them up my way. :thmbsp:

Oh yeah, QLS (http://www.bobbyshred.com/infinity/QLS.html).


Just general info for any vintage Infinity fans, keep these websites in mind.

Infinity Classics (http://www.infinity-classics.de)

Bobby Shred's Vintage Infinity Speaker Page (http://www.bobbyshred.com/infinity.html)

Infinity Classics Yahoo! Group (http://launch.groups.yahoo.com/group/InfinityClassics/)

- JP

[Negotiableterms]

I still have them, but they're sitting in storage, inappreciated. I also have a pair of almost-mint IRS Betas, and those are all the Infinity fix I need, so the QLS's stopped being a priority to restore.

I'd still like to get it done though, so Orange County seems like the place. Cheaper shipping, too. The main problem with large full-scale speakers: they're impossible to service and transport.

You'd think I'd have better things to gripe about, no?

[Charivari]

You mean these Betas (http://www.infinity-classics.de/infinity/models/IRS-series+Beta+Gamma-Delta-Sigma-Epsilon-1988-95-98/IRS-Beta/body_irs_beta.html)? Ok, I hate you now. Those are the little sibs of my dream speakers, the IRS V (http://www.infinity-classics.de/infinity/models/IRS-series+Beta+Gamma-Delta-Sigma-Epsilon-1988-95-98/IRS/body_irs.html), and I'd probably stand a good chance of being happy with just those. And to have a pair of QLS-1s to boot. Yep, I'd love to have your problems. Say, I know someone who'd fix up those QLS and appreciate them. :naughty: (Having brought back a pair of Q2s from the dead -- hacked crossovers, damaged Watkins sans foam, and 3 out of 4 midrange domes with broken tinsels.)

- JP

[Negotiableterms]

I think my QLS's need a lot of work. They need cabinet work, wiring, crossovers, drivers, etc., etc... At the price today of EMIT drivers, it wouldn't be cheap, and I think the dome midranges are unobtanium, as is the mid-bass coupler.

I usually get this stuff wrong, but... you're a student, right? EE or something similar? Either way, you're way too young to have insomnia!

[Charivari]

The domes are very difficult to locate, I saw a matched pair sell on eBay for $175 several months ago, and most all speaker repair places won't even touch them. Fortunately, through frustration and a strong desire not to be defeated by a broken tinsel, I figured out a way to affect a repair that works for me, though isn't particularly pretty. The EMITs can be fixed using a rear window defrost repair kit, or so I've heard. Fortunately, mine were the only things working on my Q2s when I got them. The midbass coupler shows up a bit more often than either of those, having been used in several Quantum models. I believe there's a pair on that auction site right now, though a bit rusted. The 5 ohm pots in the crossovers are horribly prone to going bad, which is the last thing mine need to have fixed (I'm still looking for a suitable substitute.) With enough desire and drive, the Quantum models can be brought back to life.

I typed up a quick how to on the dome repair a while back that can be found here (http://audiokarma.org/forums/showpost.php?p=407666&postcount=13), for anyone looking for a fix.

I'm an English lit student and yes, I really shouldn't be up. It is a condition I shall endeavor to correct now.
- JP

[lab]

The crossovers in the QLS and several of the smaller brethren were remarkable. Gigantic air core inductors because of the dual drive woofer and the very low crossover points, and elaborate, of course, because it's a four way design with an additional tweeter thrown into the mix. I heard them at a friends house for a couple of hours and they sounded quite good, but the bass wasn't what I'd been expecting. (His music choices perhaps?)

I've owned Quantum 3's and loved them, but I was too stupid to put a decent sized amp on them. All I had was a 100 wpc BGW amp which was pretty insufficient. When I finally traded them in at a store; to test them out, the salesman blasted them with a 250 wpc amp and they sounded wonderful. I should have backed out of the trade-in right then, but I felt committed. And probably should have been in retrospect.

[bully]

Soundcraftsmen amps would do the trick, as would a Yahama M-80 or M-85. These amps are all stable into 2 ohm loads.

[jim_arndt]

Hi Folks,
Thanks for the great information, great website. I'll post some pictures soon of the QLS's. I wasn't able to get them out of storage yesterday, I couldn't find anyone to help me carry them.... I was able to open up the outer box, they are double boxed in the original Infinity boxes. The inside box looked clean so I'm hoping the speakers are preserved well.
When I boxed them up over ten years ago, the woofers needed repair and I remember the crossover needed work, the midranges would cut out when turning the adjustment dials.
Reading this website is getting me very excited about what I'll find when I can open the boxes.
Thanks for all your help.
Jim

[Charivari]

When I boxed them up over ten years ago, the woofers needed repair and I remember the crossover needed work, the midranges would cut out when turning the adjustment dials.
Jim,

What you've described is two of the four most common issues with these older Quantums, and the two easiest to fix. In fact, they've already been mentioned. The first was because the foam surrounds were rotting, correct? If so, you can order a repair kit from Orange County Speaker Repair (http://www.speakerrepair.com), though bear in mind you'll need an exacto knife to trim the cardboard gasket segments (they're a bit too large), but that's a simple matter. The issue with the midranges is due to the 5Ω 25W potentiometers that control the levels going bad with age. I've not found a suitable substitute yet, but perhaps someone like GordonW, an AK member a pro speaker repairer, can help out on that. Your control may only need a good cleaning with DeOxit or a manual cleaning akin to the AR 3 type posted several times around here.

Now, why would you need help moving them? They're only spec'd at 190 lbs apiece. :thmbsp:

- JP

[jim_arndt]

Hi Folks,
Thanks for the input. The more I research this, I'm really getting excited about what I have. I have a Dynaco 416 with the c-100. The Dynaco needs a little work and the C-100 won't charge (bad cap?) My dad used to power the QLS's with this amp, but I thought it was always weak in the bass.

If I get serious about investing in fixing up these speakers, is the Dynaco 416 a good match for this speaker? Does the Dynaco do well with the 2 Ohm load? I was thinking of picking up a 2nd 416 on ebay, and powering the speakers in a dual amp configuration. The Infinity QLS manual recommends one amp powering the left speaker, and the other powering the right speaker (to keep the Watkins woofer from sucking the power supply dry). One channel of each amp would power the woofer, the other channel the mid and tweeters.

I've got such a rare collection of equipment left over from my dad, I wouldn't mind investing some dollars to get this equipment sounding good.

I remember my dad commenting "Mom would leave me if she knew how much money I spent on these speakers." I think I remember him saying he picked them up used for $2000, that would be around 1978.)

All this stuff has been sitting in my moms garage for 20 years. If you had this treasure chest to play with, how would you set it up?

Pair Infinity QLS's
Dynaco 416 with C-100
Dynaco stereo 70
Dynaco Mono amp (I believe 35 watt per channel, factory built)
Dynaco Mono amp (same as above, but unbuilt kit.)
Pioneer Spec-1 Pre Amp
Hafler dh-101 Pre Amp
Pioneer TX-9500 II Tuner
Phase Linear 400 (Mom smoked it)
Techniques SL-1300 turntable
Heathkit AD-1702 electronic crossover

Thanks,
Jim

[Charivari]

Jim,

You might want to consider starting a new thread in one of the other forums, say General Audio, or several, such as one in the Tubes forum for your tube gear, etc so your questions can get the attention they deserve. I'm afraid I don't know too much about the gear you do have, other than it appears to be an incredible setup.

If I might make a recommendation, that unbuilt Dynaco kit could fetch big bucks on eBay, since unbuilt kits are so rare and collectors love them. If you're not too sentimentally attached to that one piece, the funds you could earn from it would pay for proper refurbishment of all the rest, I think.

Just a little note, I was reading a Stereophile review on the big Infinity Betas like Negotiableterms has (man, am I jealous of those) and read a mention that Arnie Nudell, the man behind Infinity, referred to voice his big speakers with tubes. So, it might be worth considering trying out the mids/tweeters section of those big Quantums with some of your tube gear and have the big SS gear on the Watkins.

Incredible treasure stash you have there, from what I can tell. Your father must've been quite the enthusiast. Here's to hoping you can get it all fixed up and enjoy the nostalgia.

- JP

[jim_arndt]

Hi Folks,
I finally got the QLS's out of storage. Bad news, the woofers were removed and losts. Yes it was me, 20 years ago when I was young and dumb and owned a screwdriver. I removed them to get them repaired, had no idea where to bring them, and ultimately re-boxed them up in a separate box. Unfortunately that box cannot be found.

The speakers were well packaged in plastic and double boxed in the original Infinity boxes. So I've got a pair of Infinity QLS's in decent shape, less two woofers. What is the likely hood of finding a pair of replacement woofers?
Jim

[Charivari]

So I've got a pair of Infinity QLS's in decent shape, less two woofers. What is the likely hood of finding a pair of replacement woofers?
Jim
Pretty good. Any 12" Infinity-Watkins woofer will work with your speakers and fortunately for you, essentially the same woofer was used for several series of Infinity speakers over a span of 10+ years. However, the original woofers for your Quantums had the paper cone while all the others went to poly. I'm uncertain if this will produce any detrimental effect or would actually be an upgrade. As to availability, watch eBay. A pair of Watkins tend to crop up every two or three weeks, so just be a little patient and you should be good to go.

- JP

[Negotiableterms]

...However, the original woofers for your Quantums had the paper cone while all the others went to poly.

I think only the early QLSs have paper. Mine have poly, and they're original. There are at least two production versions. In the later version, the mid-bass coupler is moved to a different spot. I think there are more variations than that, although I've no idea how to track this.

JP is right about everything else, as he usually is.

[SicMan]

I heard a set of those in a listenning room at Tech HI-FI when I bought my first set of Q3's in 1979, they used a large SAE amp to drive them, what a sound. I just couldn't spring for a set of those at the time. Now I'm kinda sorry I didn't :no: . BUTT! my 2 sets of Q3's are starting to sound real good now that I re-foamed one set and now drive each set with a Kenny KR-9600, they sound real good even though one is still a little crippled by a bad dome mid-range. I posted some pics of one of the sets in another thread with a set of JBL 100 Studio monitors on top of them.

:banana:

[Charivari]

I think only the early QLSs have paper. Mine have poly, and they're original. There are at least two production versions. In the later version, the mid-bass coupler is moved to a different spot. I think there are more variations than that, although I've no idea how to track this.

JP is right about everything else, as he usually is.
Wha-what? I was wrong about something? I can't even remember the last time that happened. (j/k) :D

From what I've read, the poly Watkins were introduced with the Reference Series immediately following the Quantum series and were the first poly cones in the industry. Maybe your QLS were produced towards the end of the run and overlapped with the RS production. If that's the case, then being Infinities TOTL speaks, it only makes sense that they'd incorporate technological advancements into it as they figured out new things.

- JP

[SicMan]

Some large ones for sale, and if you search the speakers and subwoofers section there's alot more! AHHHHHHHH!!! what do I do? :scratch2:
:music:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5843926271&fromMakeTrack=true

[Charivari]

Some large ones for sale, and if you search the speakers and subwoofers section there's alot more! AHHHHHHHH!!! what do I do? :scratch2:
Buy 'em. Buy 'em All!! Muah haha. :nutz:

I saw those Kappa 9s and dreamed the good dream. A shame I can't afford a pair of those, but then again, I'm holding out for the real bigguns: QLS-1s, IRS V/Betas, QRS, and maybe allow for the Ren 90.

- JP

[Army]

I haven't had time to wade thru this whole thread yet, but have seen mention of different Infinity drivers needing repairs. My non AK buddy Jim can fix most if not all of them very reasonably, example: any size woofer refoamed $35 a pair total plus shipping. He specializes in Infinity drivers and has been repairing these for years. As long as they haven't been driven to voice coil melt down, more than likely they can be repaired. Pm me if you need the hook up!

[SicMan]

...... I'm holding out for the real bigguns: QLS-1s, IRS V/Betas, QRS, and maybe allow for the Ren 90.

- JP

Yep, those would be good! All playing at the same time :music:
.
.
.
.
.
,

http://uspug.com/A/trespassing.jpg

[Charivari]

Yeah, I hear ya SicMan, all those big Infinities playing at once would probably be my audio nirvana. Heck the IRS V and IRS Betas have those separate bass towers that I'd love to have with any speaker. Mmm, down 1.5 dB at 14 Hz anechoic, that's the thing dreams are made of.

On a related note, I downloaded the correction values for my Radio Shack SPL meter last night and made a disc of test tones to match the values. Today, I've been doing some measurements without the Quantum 2s particularly well positioned or anything and the results have been amazing. In my room, my Q2s (spec'd at -2 dB at 24 Hz anechoic) are only down 9 dB at 10 Hz, 4 dB at 16 Hz, and flat +/- 2 dB (aside from one - 7.5 dB room mode at ~63 Hz) from 18 Hz on up to 100 Hz. No, I did not have my subwoofer engaged at the time, so, wow, those Watkins are amazing. Just imagine the QLS-1s that are supposed to only be 2 dB down at 18 Hz anechoic. Or more incredibly what 12 of them as in the bigger IRS series must do if just 2 can do this so well.

- JP

[SicMan]

I'm salivating!

[Army]

Yeah, I hear ya SicMan, all those big Infinities playing at once would probably be my audio nirvana. Heck the IRS V and IRS Betas have those separate bass towers that I'd love to have with any speaker. Mmm, down 1.5 dB at 14 Hz anechoic, that's the thing dreams are made of.

On a related note, I downloaded the correction values for my Radio Shack SPL meter last night and made a disc of test tones to match the values. Today, I've been doing some measurements without the Quantum 2s particularly well positioned or anything and the results have been amazing. In my room, my Q2s (spec'd at -2 dB at 24 Hz anechoic) are only down 9 dB at 10 Hz, 4 dB at 16 Hz, and flat +/- 2 dB (aside from one - 7.5 dB room mode at ~63 Hz) from 18 Hz on up to 100 Hz. No, I did not have my subwoofer engaged at the time, so, wow, those Watkins are amazing. Just imagine the QLS-1s that are supposed to only be 2 dB down at 18 Hz anechoic. Or more incredibly what 12 of them as in the bigger IRS series must do if just 2 can do this so well.

- JP

Oh hell ya if your gonna dream, dream big :yes:

IRS Betas big bad ass, WAF :no: I'd give my... oh never mind...

No you don't have that problem (WAF) yet, Don't do it JP :nono:

Yeah right, one day some sweet little thing will turn your head and all your hard work will either be a blessing or a curse :yes: Choose wisely!

If it wasn't for you and Grumpy steering me in this direction a while ago, I would have never known just how good those Watkins woofers and ribbon tweets and mids sound :thmbsp: :thmbsp:

I think I may have to buy a meter, curiousity is killing me, damn those Watkins go low. I wonder how more clean power would change things :yes:

[Negotiableterms]

damn those Watkins go low. I wonder how more clean power would change things

I've done that experiment. More power will help a lot, if it's the right kind. The impedence curve on the Watkins looks like the swiss alps, so the amp has to be a true voltage source down to 2 ohms. Sadly, that means BIG BUCKS, because there are few vintage units that will do it. 200w @ 8 ohms = 800w @ 2 ohms... most amps fry themselves long before that.

To really hear what they can do, you're lookin for one of those 150 lb gorilla amps, like Threshold, or Krell, or maybe one of the big McIntosh units that has 2 ohm taps.

It's the curse of Infinity: great bass, if you can deliver the power, and a muddy mess if you can't.

[Army]

I've done that experiment. More power will help a lot, if it's the right kind. The impedence curve on the Watkins looks like the swiss alps, so the amp has to be a true voltage source down to 2 ohms. Sadly, that means BIG BUCKS, because there are few vintage units that will do it. 200w @ 8 ohms = 800w @ 2 ohms... most amps fry themselves long before that.

To really hear what they can do, you're lookin for one of those 150 lb gorilla amps, like Threshold, or Krell, or maybe one of the big McIntosh units that has 2 ohm taps.

It's the curse of Infinity: great bass, if you can deliver the power, and a muddy mess if you can't.

Pretty much what I was thinking, although at reasonable listening levels my old Sansui's ( G-22000 at 300+ wpc in 4 ohms, and only for short term my G-801, till the Big G comes back home) have been sounding very nice for the most part. I'm thinking maybe an Echowars rebuilt Spec 2 at 500wpc in 4 or a couple of others. I only wish I had the bread for brands of Amps you mentioned. Someday I may get there, but like anything good, it takes time.

I'm not doing too bad for a guy who took 20+ years off from audio, nirvana is close at hand! I've found the most important part [(the voice of the system) (a very good sounding speaker)] !

[Negotiableterms]

...I only wish I had the bread for brands of Amps you mentioned. Someday I may get there, but like anything good, it takes time.

May not be as far off as you think. Any of the Mc amps with above 200w and a 2 ohm tap will work just fine, and many of those don't sell for astronomic prices. The designer gear always does, but I actually think the Mc gear will sound better because the autoformers (so avoid the MC7200) take the hard edge off those EMITs and EMIMs.

[bocoogto]

I've never heard the QLS-1, but have a pair of Q-2's and Q-3's, which use all the same drivers as the QLS-1--just less of them. The Watkins woofer was specified to go lower in the QLS-1 only because of the larger cabinet volume. Mr. Watkins has said that this was a problem in that the cone excusion was not limited enough by this larger volume, and could be easily (over 200 watt peaks) driven to the mechanical end of cone travel. The Q-2's will bottom out for the same reason, but not as easily. The Q-3's handle a lot of power and the low end is a good compromise with cabinet volume. There is usable output into the 25-28 Hz. range. The Q-2's are usable about 5 Hz. lower than that. This occurs with VERY low frequency peaks, especially on home theater sound effects.

As for sound quality, the Q-2's and Q-3's are the best speakers I've heard in a home setting. Some of you may know the tweeters are offset from center, so there is a left and right speaker designation. The imaging and dispersion are outstanding. When I A/B these with my AR LSTII's, there is no comparison with imaging, dispersion, low end extension, and lack of listening fatigue.

[Charivari]

The Q-2's are usable about 5 Hz. lower than that. This occurs with VERY low frequency peaks, especially on home theater sound effects.
Seriously, 5 Hz? Wish I could find a correction value for my SPL meter that is that low, but that is impressive. That could explain why when I was watching The Matrix Revolutions the day before yesterday (all my neighbors are gone, so for once, I could crank it above the 85 dB mark) I had stuff falling down all over my apartment. 'Course all the rattles everywhere are a pain and I'm running out of sticky tac taking care of them. Though, I now know that the resonant frequency of your typical chair is right around 12 Hz and they do rattle quite nosily there.

- JP

[Negotiableterms]

Seriously, 5 Hz? Wish I could find a correction value for my SPL meter that is that low, but that is impressive. That could explain why when I was watching The Matrix Revolutions the day before yesterday (all my neighbors are gone, so for once, I could crank it above the 85 dB mark) I had stuff falling down all over my apartment. 'Course all the rattles everywhere are a pain and I'm running out of sticky tac taking care of them. Though, I now know that the resonant frequency of your typical chair is right around 12 Hz and they do rattle quite nosily there.

- JP

JP, I think he meant that the Q2 goes 5 Hz lower than the Q3's 25-28 Hz, meaning 20-23 Hz, rather than actually going down to 5 Hz. This sounds reasonable, while 5 Hz sounds like a recipe for amp death.

[Charivari]

Well, then, that doesn't exactly explain the 10 Hz I've been enjoying. I do remember playing my promotional copy of Telarc's CD of Symphonic Star Treck rather loudly when track 5 "The Destruction of Praxis and Its Aftermath" cued up with its very strong 5 Hz signal. The books that fell of my bookshelves and the cassette deck and VCR that vibrated and fell out of my equipment rack attest to the Q2s putting out something strongly down pretty low.

I used to believe my 24 Hz rated (anechoic) Q2s only went a few Hz lower than that spec in room. It took doing the actual measurements to realize that that was most certainly not the case. You can't just assume with these speakers, as I learned.

- JP

[Charivari]

Oh hell ya if your gonna dream, dream big :yes:

IRS Betas big bad ass, WAF :no: I'd give my... oh never mind...

No you don't have that problem (WAF) yet, Don't do it JP :nono:

Yeah right, one day some sweet little thing will turn your head and all your hard work will either be a blessing or a curse :yes: Choose wisely!

If it wasn't for you and Grumpy steering me in this direction a while ago, I would have never known just how good those Watkins woofers and ribbon tweets and mids sound :thmbsp: :thmbsp:

I think I may have to buy a meter, curiousity is killing me, damn those Watkins go low. I wonder how more clean power would change things :yes:
Nope, no concerns with WAF just yet. So, I'm trying to amass my favorite really big speakers beforehand, so the lucky girl (of course she'd be lucky, I'm just so dang handsome afterall) will know what she's getting in to and hopefully accept my hobby. It should be easier if I already have the stuff rather than trying to obtain it.

Now there you go about those EMIMs. You just couldn't leave me happy with my Watkins and my EMITs, you had to go and make me jealous of those. I've often wondered if the planar EMIM allows the best of my favorite audio worlds (the bass and highs of the Infinity Quantum series with the magical planar midrange of Magnepans). Sigh, now I have to go make my internet rounds and see if I can find a pair of big Infinities with EMIMs in my price range and in driving distance. :sigh:

- JP

[Negotiableterms]

Nope, no concerns with WAF just yet...

Now there you go about those EMIMs. You just couldn't leave me happy with my Watkins and my EMITs, you had to go and make me jealous of those.

1. I thought you moved to the middle of Washington for a girl so good-looking you couldn't resist. It's already too late, no?

2. Don't forget the SEMITs and the EMIRMs.

Seriously, if you come to Tahoe, I'll break the Betas out of storage for a little listening... even longer if you bring the good-looking girl! :naughty:

[Charivari]

Seriously, if you come to Tahoe, I'll break the Betas out of storage for a little listening... even longer if you bring the good-looking girl! :naughty:
You got it! Though, I dunno if it'd be possible in the next year or so. For the record, I moved here for the university and stayed for the girl. Might be able to get her to come along, if I can figure out a good excuse for driving down that way. Btw, 'twas personality and mind that won me over (though her looks didn't hurt); she can run mental circles around me when she gets going.

Aw, but I don't know if I could stand to hear those Betas. I tend to be very critical of speakers, so I may be safe, but if those speakers are half as good as I believe, then it'll be very difficult to ever be satisfied with my own ever again.

- JP

[bocoogto]

I think some of you are a little optomistic about the the low end response of the Watkins 12" woofers. As I previously stated, I have Q-2's and Q-3's. When using a sine wave frequency sweep, the output is down considerably by 20 Hz. and nearly non-existent by 16 Hz. This is VERY good low frequency response, but at 10 Hz. and 5 Hz., I'm afraid you'll need one of those fancy "fans" that cost over 20K.

[Negotiableterms]

I think some of you are a little optomistic about the the low end response of the Watkins 12" woofers. As I previously stated, I have Q-2's and Q-3's. When using a sine wave frequency sweep, the output is down considerably by 20 Hz. and nearly non-existent by 16 Hz. This is VERY good low frequency response, but at 10 Hz. and 5 Hz., I'm afraid you'll need one of those fancy "fans" that cost over 20K.

I wasn't gonna rain on JP's parade, but I'm forced to agree. There are almost no speakers that go that low, cause the energy demands are huge, and the impedence curves become unstable, at best. For the Betas, the Infinity Servo-Crossover cuts out everything below 16 Hz, I think.

One of the ugliest sounds in the world happens when the Servo-Crossover goes into a gain-mismatch loop. The two woofer towers HOWL at about 120 Hz (a guess). Bigger amp, louder howl. Nauseating, and so loud you have to cover your ears to get to the amp and cut it off.

[Charivari]

To which, I will once again repeat, that -9 dB at 10 Hz was measured in room with a meter that have seen widespread use in the audio community and applied correction values that have been calibrated against industry standards. The numbers I posted above aren't just what I think or assume from just looking at the woofer and anechoic specs, they are hard data. I can post the exact numbers and correction values if this continues.

- JP

[Charivari]

:no: Sigh ... :sigh:

Here are my measurements with the correction values. This set I used, correct for my meter parts number (they've changed a little bit in gain over the years, though not by much), was first cross-checked against four different recommended sources and all were within 0.5, so I used this particular set as it appeared to be the most trustworthy. The frequencies measured are a bit spread out, but this was a "just for the heck of it" task, so I didn't feel like sitting down for a couple of hours worth of finer measures. Besides, I don't have my Quantums particularly well setup, so I didn't want to put too much work into this.

Equipment used isn't anything particularly great.

Source: Toshiba SD-4960 (Multi-channel output)
Preamp: Onyo TX-DS696 (Home theater receiver, as I use the Quantums for movies. Tone controls disabled.)
Amp: RadioShack MPA-250 (budget PA amp bought at a super low clearance price at the local radio shack. Volume pots maxed out to minimize effect.)

The data with a rough guestimate of 94 dB as the average (neighbors were gone, so I could crank it. :D ):

Frequency / Correction Value (dB) / SPL Reading / SPL Reading (Corrected)

10 Hz / +20.5 / 65 / 85.5
12.5 Hz / +16.5 / 69 / 85.5
16 Hz / +11.5 / 79 / 90.5
20 Hz / +7.5 / 85 / 92.5
25 Hz / +5 / 89 / 94
31.5 Hz / +3 / 92 / 95
40 Hz / +2.5 / 93 / 95.5
50 Hz / +1.5 / 91 / 92.5
63 Hz / +1.5 / 85 / 86.5
80 Hz / +1.5 / 94 / 95.5
100 Hz / +2 dB / 94 / 96


I could also draw a picture, but I've never been all that good of an artist nor am I all that good at using Excel to graph stuff.

- JP

Edit: Forgot to describe the room. Fairly square room 15.5' deep and 16' wide, but it opens completely (no door, so L shaped overall) into the 8'x8' kitchen on the right, facing the speakers. There is a 4'x2.5' coat closet filling the corner directly across from the kitchen. Wood-suspension, carpet covered floor, moderately strong slightly soundproof walls between apartments, but inner walls are a bit on the thin side as per standard construction ~12 yrs ago.

The speakers are a touch over 8.5' apart with the seating position (a little forward for movies) at 8.5' distant; there is slight toe-in. The right speaker is positioned just slightly right of middle before this kitchen opening. The left is ~1.5' in front of the bathroom door (closed) behind, so that's approx. distance from back. The bathroom wall is a bit thin/resonant to lower frequencies, so may act a bit as a resonator (bass amplified inside to point where some notes at high volume can slightly deflect water from the sink faucet.) Same distance between speaker's left side and side wall/bedroom door -- needed to provide a pathway. The right speaker is ~3.5' from right wall.

[kfa888]

Wonder what is causing the dip at 63 Hz?

[Charivari]

I just added some details about the room. Basically, all rooms smaller than a touch over a full-wavelength can create modes at certain frequencies. This is particularly bad with square rooms, but odd shaped rooms like mine can help to break it up. Your standard room tends to have a room mode between 40 - 70 Hz, with the larger the room, the lower the frequency. To ignore a bunch of facts, the sound wave acts like a wave in a bathtub, when it sloshes around, it can stack up on top of a reflected wave from the other side and create a peak, it can align with a trough from said reflected wave and cancel out, or it can do as in my room, have the two troughs line up and create a null or dip in frequency around a certain resonant frequency. For my room, it's around 60 Hz, so near as I can tell, but it's influence is a bit spread out.


So you know, this largely happens with lower, bass frequencies where the wavelength is greater than the dimensions of the room. This is also what helps with so-called room gain, lower frequencies are boosted in a room vs. anechoic or half-wave (outdoors) situations because the wave is mostly trapped. This is why a speaker spec'd at -2 dB at 24 Hz can be down just 9 dB at 10 Hz, so long as the woofer/box combination still has some output. I've read that room gain at certain lower frequencies, depending upon the geometry can be upwards of 20 dB, but this info I obtained from some serious home theater enthusiasts, so it might not be audiophile approved. Once you move up in frequency so the wavelengths are less than the room size, you start having geometric nodes involving reflections off of walls and objects rather than the room acting as a resonant box.

There's lots of books and articles that have to be read to go into further detail.

- JP

[Army]

There's lots of books and articles that have to be read to go into further detail.

I'd say you've done more homework on this than most of us would go to the trouble of.

Color me impressed :)

[jim_arndt]

Well my QLS-1's will have to wait a little longer before they get a set of watkins woofers. A set just went for $429 on eBay, I was thinking that was a bit high.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5855123354&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1

Hopefully another pair will come up soon...