Recommended Infinities

89-300ce said:
Those RS-IIA/B's look good to me. How are they to drive? I wouldn't want to risk frying an amp just to listen to music. The RS-IIIA/B look similar but with one EMIT and a polydome mid. Would this be easier to drive? Easier to maintain? Do the RSIIIA/B's have conventional bass drivers?
Although they still benefit from plenty of power, the RS-II and RS-IIIA/B are both easier to drive than the big Kappa's. 200 wpc would work fine for either one. Both use the same 10" poly cone woofers. I have a pair of RS-IIIB's (see my avatar) that I've had for going on 18 years driven by a 200 wpc Adcom amp, and the only problem I've had was the foam woofer surrounds needing replacement several years ago. Other than that, they look great and sound awesome. The only way I'll move them on is to make room for some RS-II's.
 
Thank you all. I think I'm getting a feel for Infinity. The RS series with dual 10's appeal to me, but I will look at any that come up.

Thanks again.

Jorg
 
I picked up a pair of RS 2.5s for a song ($128) then had the woofers refoamed for $50. Add a $5 bottle of orange oil for the cabinets, $3 for hardwood knobs for feet and I've less than $200 into a set of mighty fine speakers.

The expensive part was the pair of big amps to drive them - 375 wpc total.

Very happy with them although I agree that string quartets are not as euphonics as I would hope, even on SACD.
 
I listen to mostly blues/rock like Bob Dillan, Lou Reed, Jennifer Warren,
A3, Santana, that kind of stuff. Should I be concerned about the EMIM's. I like acoustic bass and guitar but seldom listen to orchestral music or string quartets.

Jorg

PS. I would gladly run out for another amp if I could find a score like that.
 
89-300ce said:
I listen to mostly blues/rock like Bob Dillan, Lou Reed, Jennifer Warren,
A3, Santana, that kind of stuff. Should I be concerned about the EMIM's. I like acoustic bass and guitar but seldom listen to orchestral music or string quartets.
Jorg
PS. I would gladly run out for another amp if I could find a score like that.

Jorg,

Don't worry about the EMIMs. There's a reason Infinity put them in all their top line gear from the RS-4.5 on: they sound great.

My comment about the polycones was just that, for certain types of music like string quartets and some chamber music, they sound very smooth and, to my ear (YMMV), are in many ways more pleasing to listen to than the EMIMs. I doubt, however, that they are more accurate than the EMIMs, which are extremely clear and detailed. For general purpose listening, I would choose the EMIMs hands down every day.

And you're right, Whitehall got a major score there.

David
 
agreed I have pair of RSII

Tedrick said:
Although they still benefit from plenty of power, the RS-II and RS-IIIA/B are both easier to drive than the big Kappa's. 200 wpc would work fine for either one. Both use the same 10" poly cone woofers. I have a pair of RS-IIIB's (see my avatar) that I've had for going on 18 years driven by a 200 wpc Adcom amp, and the only problem I've had was the foam woofer surrounds needing replacement several years ago. Other than that, they look great and sound awesome. The only way I'll move them on is to make room for some RS-II's.
, bought them in 1981 /brand new. Refoamed all four woofers in
1997. reciever.amps have changed, buy RS II's have not:music: :music: :music: :music:
 
89-300ce said:
Thanks for all the information. I think if I stayed away from models with the Watkins woofer I would save myself some issues with repairs as well.

No love for the RSIIIA/B's ?
Jorg

Jorg,

I don't understand your statement about the Watkins. The only repair would be a little refoam job, like any other vintage speaker. Other than that, I'm not aware of any other problems with them.

I've only had the good fortune to hear one model of Infinities (yup, mine :D ) and I just can't imagine an Infinity without a Watkins in it. This is one fine woofer.

I think the power debate here can get a little out of hand though. The biamping and huge-a-mongous power amplifiers is all fun and part of the continual quest for perfection that we all have as enthusiasts......but there is a nominal reality. I run a single Adcom GFA 555II (325 WPC @ 4 Ohm) on the Quantums 2's. I haven't fried any Emits or domes, nor has the Adcom gone up in smoke. I've had the system cranked at what I would consider pretty insane SPL (just for hell of it) and was watching intensely the Adcom's distortion meters for any blinking......notta. Sustained listening would have been causing damage to the ear follicles as far as I'm concerned. I usually listen at moderate levels, enjoying the sound QUALITY as opposed to the quantity.

Just giving you a baseline on Amp vs Speaker model that is known to work.

The effect of good clean power on any set of speakers is incredible. The Adcom on my Mach 2's, Pioneer HPM 60's, or AR 2's is just amazing compared to powering them on the Denon AVR 1604.......no contest. I'ld be throwing them in the dump after listening on the Denon, but not after the Adcom was wired up. Totally different.

I would say that if huge rock concert level SPL is what is desired, then the more efficient Klipsches (I've heard some Klipschorns, and they are a VERY VERY fine set of sound-eminating-electromechanical-devices), JBL's etc would be a better choice.

Jorg, buy the best set of speakers for their potential sound quality, and then worry about the amplification requirements later, which is easier to obtain than the speaker is.
 
89-300ce said:
KenCat,

At this point I'm just guessing at all things Infinity, but, isn't the Atkins woofer the one with the feedback loop? I know nothing about servicing speakers but I would think something so rare would be difficult to repair/replace.

Jorg

Ahh, that's where the confusion is from. Infinities first speaker, the Servo-Statik-I had the servo controlled 18" woofer. The IRS Beta was another feedback woofer model. There may be others that I'm not aware of. Here's an interesting link to a Stereophile review of the Betas: http://www.stereophile.com/floorloudspeakers/988infinity/

Back to the Watkins Woofer. NOPE, no feedback loops inherent in the design. They are a standard type woofer, except for an additional and separately wired (fed) voice coil inside the magnet. They look the same as other woofers but are given away by the 2 sets of terminals for hooking up 4 wires to each. Each voice coil has it's own crossover circuit. The second voice coil kicks in at low frequencies to pull down the impedance rise at resonance (just parroting what I've read - don't really understand all the EE involved :D ). The Watkins are as repairable as other woofs, in fact the inventor Mr. Watkins is still in business and will repair them, and has parts and perhaps even new ones (read something on that I think). Spare woofers come up for sale on ebay and elsewhere. Other than the foam surround though, nothing else should really go wrong. And did I mention the deep clean bass ? :yes:

Check out the post here by Vitopanch - good summary of the models with Watkins in em: http://audiokarma.org/forums/archive/index.php/t-87469.html

I came across this great little webpage by an Infinity enthusiast - great pics of the various models (but the Quantum 2's are labelled wrong :sigh: as they sit beside their big brother QLS's):
http://www.davidsaudio.com/html/infinity_.html


And here is an amp that should play most any Infinity. Now, if your budget is like mine, neither of us will ever see one of these, but it's fun dreaming eh? (Edit: a neat aside is that this is designed by John Ulrick, co-founder of Infinity)
http://www.enjoythemusic.com/superioraudio/equipment/0306/spectron_audio_musician_iii.htm
 
Ken,

Thanks for the correction. I'm confused though. In one article I see this comment

"Another thing to know is that the Watkins woofers do not really require more power per se. They lower an inordinate high impedance at resonance to be equal to impedance in the midrange and draws the same power to deliver the same at low and mid frequency range."

suggesting that they should be easy to drive, yet in another article I see this

"It replaced the servo woofer of the Servostatik with the Watkins dual-coil woofer, giving it amazing bass. Those woofers also ate amps for lunch, so you need some serious amplification to get the best out of these."


????

Do you have a link that explains how the Watkins woofer works?

Jorg
 
89-300ce said:
Ken,

Thanks for the correction. I'm confused though. In one article I see this comment

"Another thing to know is that the Watkins woofers do not really require more power per se. They lower an inordinate high impedance at resonance to be equal to impedance in the midrange and draws the same power to deliver the same at low and mid frequency range."

suggesting that they should be easy to drive, yet in another article I see this

"It replaced the servo woofer of the Servostatik with the Watkins dual-coil woofer, giving it amazing bass. Those woofers also ate amps for lunch, so you need some serious amplification to get the best out of these."


????

Do you have a link that explains how the Watkins woofer works?

Jorg


Jorg,

We're talking two different issues here. The Servostatik had its own bass amplifier, thus didn't require a separate bass amp and hence the bass load was irrelevant.

As I understand it, the Watkins woofer does not require lots of power per se as much as an ability to handle low impedance loads and provide high current. Many amps are not designed to handle very low impedances well and hence you need an appropriate amp to properly drive them.

For example, many receivers are designed with 8 Ohm loads in mind and struggle to deal with 4 Ohm (and lower) loads. These would not be a particularly good match for Watkins woofers, especially if you are trying to drive them loud, as you indicated in your first post. As a practical matter, there are lots of amps out there that can deal with this task quite handily, you need to get one. Lots of different amplifiers are being successfully used by various members here.

David
 
Going from 105 wpc single amp to adding a separate 270 wpc driving the woofer in bi-amp mode made a distinct improvement in bass clarity.

Power is good.
 
89-300ce said:
Do you have a link that explains how the Watkins woofer works?

Jorg


I've been searching google for awhile now for more technical info on the Watkins. It does not seem to exist. It may be buried in forum postings etc. that don't show up in searches. Funny :scratch2:

Best I've found in the way of explanations is in the brochures of the various Infinity models:

http://www.bobbyshred.com/infinity/QLS.html

http://www.bobbyshred.com/infinity/Q2.html

http://www.bobbyshred.com/infinity/RS25.html
 
Ken,

Very interesting. I'm stunned at the spec's of the Line Source
18-32 @2db. Damn!

I wonder how they time the switch between the windings?

One question. Wouldn't a midbass coupler of that size be to small to provide "impact" at that frequency?

Jorg
 
89-300ce said:
Ken,

Very interesting. I'm stunned at the spec's of the Line Source
18-32 @2db. Damn! Jorg

Hey, it's Infinity. :D

89-300ce said:
I wonder how they time the switch between the windings?

My guess is that it is the same as the "switch" from woofer to mid to tweeter - the design of the crossover circuit dictates the frequency rolloff points of each driver. Each voice coil in the Watkins has its' own circuit with a capacitor and inductor. Where one coil rolls off at its' upper crossover frequency, the other one rolls up at its' lower frequency, with overlap occuring between the two. Check out the Infinity.de site and call up the schematics for the various models. Do some research on passive crossover circuits for more on those. Ther is a ton of info avialable.

There may be more going on with the circuit though, as the QLS bochure calls it an "elaborate inductive resistive capacitive (LRC) circuit" :scratch2:(maybe that was the spin department at worK?) , but it's beyond my electronics level to decipher that part.

89-300ce said:
One question. Wouldn't a midbass coupler of that size be to small to provide "impact" at that frequency?
Jorg

:dunno: What is, works :yes: You'll have to ask Arnie Nudell or John Ulrick or Gary Christie that one :D
 
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