Infinity Quantum 2 EMIT

[walllly]

I recently acquired a pair of Infinity Q2's. I am in the process of repairing 2 of the EMIT tweeters. Originally the face plate magnets were covered with some yellow tape (which is now history). Was there some special property to this tape? Or was it just a film protective barrier to protect the diaphragm?

Also I responded to a prior thread about the spacers used to increase the dispersion of the EMIT array. If anyone knows the length of the spacers (top and bottom), I would appreciate it. Mine were removed.

Thanks,

Walllly
wgray@centennialpr.net

[Charivari]

Welcome to Audio Karma, Walllly!

The spacers for the top tweeters (that go on the bottom two screws) are roughly 1/4" long whilst those for the bottom are closer to 3/8". Exact numbers shouldn't be too important here as the spacers are for improving vertical dispersion and in fact, your speakers might sound better for a sitting person with them flush mounted and the pot turned down a bit to accommodate for the increased response.

Now, as to your other questions, I'm afraid that I haven't that particular knowledge. I lucked out with my pair in that all 8 EMITs were working, not that anything else was in them. You can read a little more about the EMITs and their repair here (http://www.bobbyshred.com/emit.html). However, if you're looking to get those two repaired, AK Mod Army (http://audiokarma.org/forums/member.php?u=1872) has a friend who does good work in repairing these for a reasonable price.

Since you're new to vintage Infinities, might I suggest a few good reads?

First off is Bobby Shred's original Infinity pages. (http://www.bobbyshred.com/infinity.html) Then there's the very informative, though German, website Infinity Classics (http://www.infinity-classics.de). Finally, if you want to talk to other Infinity owners and get their input (though the older Quantum series don't get as much attention here as the newer series), check out the Infinity Classics Yahoo Group (http://launch.groups.yahoo.com/group/InfinityClassics/).

Good luck getting those excellent speakers of yours going.
- JP

[walllly]

Thanks, Charivari: I've looked over Bobby Shred's page and the German Classics site and I'm a member in the Yahoo group, but haven't found ANYTHING on the properties of the yellow tape that was used. If you think of anything, let me know.

And thanks fot the spacer measurements.

Best Regards,

Walllly
wgray@centennialpr.net

[Charivari]

Ah well, it seems like you've already been quite busy. My best guess for the function of the tape is just to hold the diaphragm aligned during assembly (the traces need to be parallel to the magnets for best function) and more importantly, to keep the magnets from wearing through the Mylar over time from the slight flex. Perhaps standard electrical tape should suffice if you trim it into strips to the same dimensions of the original yellow tape unless you can find a very thin double-sided tape, which is what this stuff appears to have been originally.

- JP

[Kencat]

Welcome Walllly.

Nice to hear from another Q2 owner :banana:

I've included some close-up pics of those spacers. I swear the spacer tubes have the angle cut at the ends as the fit looks sooo tight to the cabinet and the Emit frame.

How about some info on your set? Mirror imaged ? Rear firing Emit? Bi-amp connections? Serial numbers? Have your woofer foams been done already?

Seems like I'm collecting this data for some reason. Interested to see if there is a pattern to the serials and the different designs of the Q2's that are out there.

Charivari has a really wierd set of serials on his. They must have been prototypes that broke out or something :thmbsp: (We need to find out the story on those JP)

Well, I'm sure we'll all be conversing with questions and listening impressions in the next while. Talk at you later.

[Charivari]

Charivari has a really wierd set of serials on his. They must have been prototypes that broke out or something :thmbsp: (We need to find out the story on those JP)
Whoa, now that's a cool thought. Ya know, one of my Q2s is nearly identical to the pair featured on the brochure. I even had a thread (http://audiokarma.org/forums/showthread.php?t=43198) discussing this, though the images are now lost. I sure would like to know if mine are something special and if there is a story behind them. I had one of mine open just a couple of weeks ago, but didn't see any special markings. I did find a flashlight I lost from four months before when I had been in to do some crossover repairs, though. :screwy:

- JP

[Kencat]

Whoa, now that's a cool thought. Ya know, one of my Q2s is nearly identical to the pair featured on the brochure. I even had a thread (http://audiokarma.org/forums/showthread.php?t=43198) discussing this, though the images are now lost. I sure would like to know if mine are something special and if there is a story behind them. I had one of mine open just a couple of weeks ago, but didn't see any special markings. I did find a flashlight I lost from four months before when I had been in to do some crossover repairs, though. :screwy:

- JP

Oh Man, :lmao: :lmao: :tears:

I'm glad you're not in pre-med.

Does the patient sound better now?

[Charivari]

The patient is feeling fine with no ill effects. The sound isn't as bright now, though.

Oddly, it didn't affect the sound much, there was a faint rattle occasionally at certain frequencies. I finally got tired of it and shook the speaker around a little bit, when I heard something thunking around inside, I opened it up and found the flashlight. It was a dumbsh~t moment, but I was happy to have my flashlight back, albeit with dead batteries.

- JP

[Kencat]

Hey, I think this might be a neat new thread topic.....What Wierd Shit Have You Found in Your Speakers?

What do you think? I wonder how often that happens? Wonder if anyone has ever found bones ? or even money?


On another topic, (you think we've hijacked Walllly's thread ?) the Veneer pattern thing is very cool. I read that old post - too bad the pics are missing - and went back to look at mine. No where near similar to that brochure model, and each speaker is very different too. No grain matching considered there. Wonder how many speakers could be made from a "run" of the same veneer? could be a bit of a time stamp maybe.

Hey Walllly (gotta ask...why the 4 l's???), can you post some pics of your Q2's ???

[walllly]

I can tell one is s/n: 7100586. They are a mirror pair. Woofers are rebuilt and working perfectly, now working on tweeters. No flashlights inside the cabinet (yet). Back to you.

[Kencat]

I can tell one is s/n: 7100586. They are a mirror pair. Woofers are rebuilt and working perfectly, now working on tweeters. No flashlights inside the cabinet (yet). Back to you.

That serial is very cool. It is only 407 away from a known Non-mirror imaged set that was made in 1976. See below.

(7100178 and 7100179) - Non mirrored with rear emit - made in Sept/Oct 1976.

(7103168 & 7206395) - mirror imaged Q3's.

(7104061 & 7104520 - Mirror imaged Q2's , no rear emit - Kencat's.

(7209404 & 7209405) - NON-Mirrored Q3's

(7207664 & 7206975) - Mirrored Q3's - bought new in 1979

(1020711 & 1020712) - non-mirrored Q2's, rear EMIT, no biamp - Charivari's

(7100586 & 7101282) - Mirror imaged Q2's, No backside tweeter - Walllly's

(7101797 & 7102422) - Mirror imaged Q2's, No backside tweeter, and biamped - Bocoogto's

Walllly, is the other serial gone or messed up ?

I am beginning to think that these Q2's were supposed to be mirrored, but between screw ups at infinity and the dealers, people got shafted.

Need more data though.

[Charivari]

Now, don't forget my 1020711 and 1020712 non-mirrored, rear EMIT, no biamp Quantum 2s. :D

- JP

[Charivari]

Hey, I think this might be a neat new thread topic.....What Wierd Shit Have You Found in Your Speakers?

What do you think? I wonder how often that happens? Wonder if anyone has ever found bones ? or even money?
Would make for an interesting thread, I seem to recall one a while back for what's been found in LP sleeves. For the bit about bones, would two dead mice and a bunch of dog food found in one of my HPM-40 Series I count?

On another topic, (you think we've hijacked Walllly's thread ?) the Veneer pattern thing is very cool. I read that old post - too bad the pics are missing - and went back to look at mine. No where near similar to that brochure model, and each speaker is very different too. No grain matching considered there. Wonder how many speakers could be made from a "run" of the same veneer? could be a bit of a time stamp maybe.
Woohoo! Hijack! But is it really a hijack to make an Infinity Q2 thread into an Infinity Q2 thread?

Anyways, here's a picture of the Quantum in question.
http://i30.photobucket.com/albums/c301/jpvanson/Misc%20Audio/Q2veneer.jpg

- JP

[Kencat]

Now, don't forget my 1020711 and 1020712 non-mirrored, rear EMIT, no biamp Quantum 2s. :D

- JP


DONE.

[walllly]

Ok Guys s/n's 7100586 & 7101282. No backside tweeter. and mirrors.

[Charivari]

Hey now, what's the deal with all these '7' serial numbers? I'm starting to feel the odd man out, but with a quick verification, I can swear that mine are '1's.

- JP

[Kencat]

Woohoo! Hijack! But is it really a hijack to make an Infinity Q2 thread into an Infinity Q2 thread?

- JP

By Jove, you are quite right young man. Carry on then.

[Charivari]

Nice avatar, Kencat. Was this last post just a chance to show it off? :D

- JP

[Kencat]

Nice avatar, Kencat. Was this last post just a chance to show it off? :D

- JP

No. Honest. When you create or change an avatar it changes it everywhere, immediately, old posts included.

[Charivari]

I am aware of that, just felt like complimenting you on your avatar and giving you a hard time while I was at it.

Hey, 400 posts, bit of a mile marker. Not long until you hit 500. Going to try to make the next 100 devoted entirely to Infinity speakers?

- JP

[Kencat]

Wow, 400! I hadn't noticed that. That's a lot of yakkin huh?

All Infinity? Probably not. I was replying to one on the Mirage speakers thread tonight, but no one came back.

Always like to get into any discussions on the Mach 2's or HPM-60's or old AR's.

The Mach's are a nice easy, smooth listen compared to the 60's which are more brash, a little irritating after a while actually. I've got the AR2's hooked up to an old HK-330C in the basement, man the bass is incredible...the bass guitar licks are so clear and just seems to linger. Very distortion free combo. :music: The basement enhances the bass somehow, cause they didn't sound as good upstairs, but then they were on the Denon too...maybe not a good match.

Oops, now that's a hijack.

[Charivari]

Just like tango, it takes two to hijack.

Haven't had any Mach series, so I can't comment. I agree with you about the HPM series, which is why I've decided to get rid of my HPM-100s. Just too peaky and harsh to enjoy for my type of music. Now, ARs, well, I've only a single AR-1, so I can't comment too much. A little bass shy, not much high end extension, but it has a very good, detailed midrange that's very realistic. Guitars sound especially good and it would make an excellent speaker for a mono setup if I wasn't so attached to having a good stereo image. Haven't driven it much as I don't want to risk a 50 year old, $1200+ speaker just to see how loud it goes. Oh, but the build quality is fantastic. I could easily see using the cab as a jack-stand on a truck with no trouble at all. Hefty little bugger.

- JP

[SicMan]

Hey KenCat! I think you flushed out a couple Infinity owners! LOL

[Kencat]

Hey KenCat! I think you flushed out a couple Infinity owners! LOL

Charivari's been carrying the beacon alone for awhile....just took another injection of new blood. Still a pretty small following though. Maybe that is a good thing, prices will remain low (well, sort of) with them not being a big thing.

Did I say these Infinities are just pure crap ? No-one wants anything to do with them. Don't even bother. Junk. Don't know why I bought em. Our ears are all messed up, don't know what we're talking about. Yup, no market for these things, ever.

(think that'll fool em ? )

[Charivari]

Charivari's been carrying the beacon alone for awhile....just took another injection of new blood.
Thanks, mate. It was a long, lonesome road to sing the praises of vintage Infinities.

Did I say these Infinities are just pure crap ? No-one wants anything to do with them. Don't even bother. Junk. Don't know why I bought em. Our ears are all messed up, don't know what we're talking about. Yup, no market for these things, ever.

(think that'll fool em ? )
Oh? ... umm ... well ... Yeah, of course! Stay away from vintage Infinities! They're all worthless with horribly flat, accurate frequency responses, ridiculously sweet tweeters that never fatigue, and painfully good bass. Stay clear if you know what's good for you and go after those peaky vintage speaks everyone raves about; they'd be eBay money better spent. That is, at least until I can snag TOTL examples of each series. Let's see IRS V, IRS Beta, QLS-1, Ren 90s .... :scratch2:

:D
- JP

[Kencat]

Thanks, mate. It was a long, lonesome road to sing the praises of vintage Infinities.


Oh? ... umm ... well ... Yeah, of course! Stay away from vintage Infinities! They're all worthless with horribly flat, accurate frequency responses, ridiculously sweet tweeters that never fatigue, and painfully good bass. Stay clear if you know what's good for you and go after those peaky vintage speaks everyone raves about; they'd be eBay money better spent. That is, at least until I can snag TOTL examples of each series. Let's see IRS V, IRS Beta, QLS-1, Ren 90s .... :scratch2:

:D
- JP

:lmao:

Merry Xmas JP,

May those TOTL's grace your living room some day.

And to all AKers out there, best seasons wishes. May all your dream speakers come to your houses some day as well.

[bocoogto]

My Q2's are S/N 7101797 and 7102422. No backside tweeter. They are mirror images (left and right) and can be biamped.

My Q3 serial number tags are gone, but they are mirror images, also--no biamp or rear tweeter.

These Quantum speakers are GREAT!!! Finding a current model system that is as good or better than these would be a challenge. Back in the 80's, I took my pair to a local audiophile store that sold Pardigm, Polk, Mission, B&O, and others. We A/B'd the Quantum 2's with a pair of large Polks about 55" high--don't recall the model--probably SDA's. The Quantums were better on low end, imaging, and were much sweeter sounding on the high end. I thanked the salesman for his trouble, took my Quantums home and have been happy with them since.

I did have a chance to A/B them in my home with Definitive Technology BP ????--with the 15" woofers and built-in subwoofer amps. The high end of the Definitives was very similar to the Quantums, but they did not produce bass as low as my Quantums.

[Kencat]

Thanks for the serials Bocoogto. I added them to the post with all the others. The serials that have a "spread" continue to be the mirror imaged sets. :scratch2:

Gotta go do the family thing for a few days so I won't be working on the Q2's. All the good comments I keep reading ....can't wait to get them operational.

Ah well, all good things in time....

[bocoogto]

Any more info on the Q2's? Did very many of them have the rear EMIT's and has anyone got photos showing how these were mounted/pointed/part number? Was Infinity the first to do this rear-facing tweeter thing? I believe all the QLS1's had this feature.

[Charivari]

Hmm, oddly, I don't have a picture of the rear EMIT. Guess I'll have to do that the next time I can steal, erm, I mean borrow my friend's better digital camera. Basically, for the left speaker (or both with non-mirrored designs) the rear EMIT sits in the upper left corner behind a circular bit of flush-mounted grill cloth identical to the rear opening on the midbass transmission line. The EMIT itself is squarer than those on the front with a 4x4 arrangement of slots over the 2x8 of the fronts.

As to the part number, the schematics show it to be #902-0157 and is connected to the front 3, just 180° out of phase. All the QLS, afaik, had the rear tweeter, but with an additional switch down on the panel to switch it in or out of the system.

- JP

[Kencat]

As to the part number, the schematics
- JP

Schematics? :saywhat: :deal: :bigok:

[Charivari]

Schematics (http://www.infinity-classics.de/infinity/manuals/Quantum_2_technical_sheet.pdf)