Infinity Epsilon/ Beta speakers-- Classsics???

There are a few "sale" posts on the 'GON for Infinity Epsilon and Beta speakers. I assume these are models that are over 10 years old. Need opinions and comments on their performance and compatibility with amp and speaker cable. Do they offer more than reasonable competition to some of today's hi-end speakers. Thank you!
Epsilons are still fairly recent and a good value used.
IRS Beta....I have a set and thus my opinion will be biased, however I feel a used set of Betas with the proper frontend will stand with almost any current "reference" speaker, at a fraction of the price. Good true full range speakers today are ridiculously overpriced IMHO.
The Betas can sound terrific. The best sound I got out of them was with ARC tubes on top and a QSC 3000Mx on the bottom. I used Cardas cables. Also had to refoam a woofer.

No experience with the Epsilons.

Good Luck!!
I owned a pair of Infinity RS-1b, the predecessor to the
Infinity Beta, and a friend owned a pair of Betas.

Yes, they are both classics. Each system has it's strengths
and weaknesses but on balance they are among the finest
of speakers EVER made. I sold my RS-1b's because I moved
and my present room is too small. Both systems are a
bargain on the used market, when they are available.

I can't speak to the Epsilons, I've never heard them.
I've got to go along with Jvogt, the RS1x series were quite good as well and a really silly bargain today. They're not perfect but damn close for the money. I've got to laugh today at the "dumbing down" of High-End. Case in point: Totem, sure, the little critters sound good, but most of these folks chasing the dream have never experienced a true full-range speaker, and never will at today's pricing. The big vintage Infinity RS1x and Beta not only gave you the music, but the excitement as well.
Have you ever been in a large church or hall with a pipe organ? If you have I'm sure you can relate to the feeling in your chest of the movement of air around the lower fundamentals. My Betas can reproduce that "charged air" in my living room with ease. Show me another speaker available used at around $5000 that will do the same!
First, many thanks to those who responded. In my original post on this thread, I meant to ask about the newer model Sigma(vintage 1997) and how it compared to the Epsilon, or other high end speakers of today. I never was a big fan of Infinity speakers, but these models seem to be much different. Therefore, any one familiar with the sound quality of the Sigma; because, I could not find any reviews on the net about them. Thank you!
The IRS Betas are hard to beat, and at the price they sell for used, giant killers. I agree that ARC tubes for the panels are a no-brainer, as they were built and tuned with these electronics. They need a big room, lots of watts and quality components in font of them. I have had them for 5 years or so and have no interest in replacing them (upgrading is now focusing on front end components).
See for thoughts on appropriate room considerations for these speakers.
Right on Beemer!!!
I have heard the Epsilon and they do NOT compare to the Batas or the RS 1-B's......I have the 1-B's and with the proper equipment tubed top and SS amp on bottom and a good source (I use vinyl)..they will sing and sling!

I came home form the NYC show two weeks ago very impressed with the speakers (the set ups) I heard (Wilson, Dynaudio, Innersound, Pipes etc).....BUT I was most impressed that after listening to my RS 1-b's later that night at home they sounded just as good(and better) then many of the rest.

I am sure you will do well with the Betas!

The best of luck!
Hello, I am also an Infinity enthusiast and have a pair of Renaissance 90's that I absolutely LOVE- they are SUPERB speakers!!! If you look around and can find a pair for approx $1500, they would be a Great buy. Have you seen the site: ?? I also very much admire the Quantum & Q models Infinity made back in the late 70's- I have a pair of Quantum 3's, Qb's and Qe's and they are all great as well. Also- the whole thing about power can be a bit exagerated- well, as far as the Ren 90's go anyway. I am also a vintage Sansui enthusiast ( -> I have quite a few Sansui amps & receivers in my collection- and all of them can drive the Ren 90's - JUST FINE. I had a new Odyssey Stratos amp ( and sold it- it was nice and all- but didnt offer anything more than the Sansui hi fi gear I already have.
I have owned the RS-1B for a long time and I had used Audio Research gear and it sounded very good. Several years ago, I bought a used pair of IRS Betas. These speakers put out a lot of bass, in fact too much even with the proper adjustments, it was just too much. I got an Accuphase D28 digital equalizer and it was magic after that. I am using an older pair of Krell KMA-200 on the bottom and Sonic Frontiers Power 3 for the top.

I have refoamed all the woofers recently. It was not particulary easy to do, but the prospect of having to spend $165.00 each or a total of $1320.00 easily made the decision for me.

If anyone is considering buying and IRS Beta or RS-1B, one does need to check the foam surrounding the woofer for cracks.
here is a link for old Infinity speakers..
The Infinity Beta is the best speaker at a reasonable price for super full range sound. The Bass uses the same 12" drivers found in the orginal Kappa speakers. The main thing to keep in mind is these speakers need a great deal of power on the bass! Infinity claimed the IRS had a 2000 watt amplifier built into the bass. That being so, I would say that something like a Bryston 7B would be the least power I would recommend.
I always liked the RS 1 and 1B better for the midrange and highs over the Beta and the Beta better for bass. Some have discussed using two bass networks, rather than one, but I think the 12" woofers in the Betas make the difference.
Both speakers are great and still today, are among the best speakers out there. The IRS is better; if you need something more than the RS1 or IRS Beta, but can't afford the IRS you can build something in between and that is where the real excitement for me begins!
i have a set of infinity IRS Betas, and the foam ring that attaches the woofer cone to the speaker has turned into dust. does anyone know who might repair them?


day radebaugh
Contact Millersound for repair of Infinity speakers-phone #1-215 412 7700-website(
Hi :
I also enjoy these speakers and in fact I bought two pairs on an auction for a very good price . I unfortunately experience dreadful sound from the speakers when I switch the amnps and this has to do with the servo's phase switch in the back which is either which 0 or 180 and I never figured it out which one is correct phase. I would appreciate if you advise me of how you figure this out.
Hi- for the IRS Beta x-over, a Non-inverted signal source,set this front panel control to 0. For an inverted signal, set the control to its 180 position on the front panel.(low freq phase)
Rear panel(low freq servo out)-0 jacks for amps that are inverting. +0 jacks are used to connect amps that are non-inverting. Hope this helps.
Hi coacher :
Thanks for your advice . I have epsilon speakers and presume the same advise is applicable for Epsilon. I will try again. Are any of the speaker's units available in the market ?