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Any Infinity QLS owners here?

Negotiableterms said:
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.
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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)] !
 
Army said:
...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.
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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.
 
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.
 
bocoogto said:
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.
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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
 
Charivari said:
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
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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.
 
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
 
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Army said:
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:
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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
 
Charivari said:
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.
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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:
 
Negotiableterms said:
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:
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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
 
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.
 
bocoogto said:
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.
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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.
 
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
 
: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.
 
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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
 
There's lots of books and articles that have to be read to go into further detail.
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I'd say you've done more homework on this than most of us would go to the trouble of.

Color me impressed :)
 
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