Price Paid:  $2900.00 from UK Hifi Dealer

Summary:
This is a review of the Infinty Sigma speakers (not the Epsilons). The price stated is in GBP.

I recently got my pair of Sigmas having been using Infinity Kappa 9 speakers. The Sigmas are so rare in the UK that I just couldn't resist when a pair became available, given that I've been a fan of the Infinity sound based on their EMIT tweeters for a long time.

The Sigmas are certainly a large speaker but beautifully built and finished. They are as tall as the Kappa 9s but deeper and more substantial in build (and the Kappa 9s are very solidly built themselves).

I have the speakers set-up with EMIT set to high (instead of neutral), EMIM set to neutral (instead of low) and the bass set to normal (instead of extended). The room I have is only 17ft by 14ft at longest dimensions and L-shaped. The speakers sit along the 14ft wall about 4ft in from the back wall and about 3ft in from the side walls. They sit on granite slabs and are toed-in very slightly towards the listening position which in my case is pretty nearfield.

So how do they sound? Exceptional. The level of detail is a very significant step-up from the Kappa 9s which are incredibly detailed to start with. At the same time, the prestation is smoother, more refined and natural. There is even better integration than the 9s which again were excellent in any case. You can listen to the speakers for hours but the excitement is there in spades.

The EMIT and EMIM drivers are superb giving fantastic transparency and sparkle and the integration of drivers top-to-bottom is excellent - no lumpiness of lack of coherance is noticable - the mid-bass coupler I think makes a bid difference in this respect in the same way it does with the Kappa 9s.

As with the Kappa 9s, the soundstaging is like that of a great planar speaker (and I've had a few) - again the use of rear firing EMIT tweeter and open back midrange driver, in this case EMIM, offer the dipole qualities while the use of the sealed-box mid-bass and bass drivers offer deep but tight solidity and dynamics to complement the transparency.

The speakers certainly need as much high quality power (current) as you can throw at them - I bi-amp with a pair of huge stereo 350wpc Conrad-Johnson EV-2000 valve-hybrid amps that deliver massive current and these can drive anything - they drive the Sigmas beautifully. I had heard them on audition at the dealer with a Sony's hi-end top of line SACD/pre/150wpc power amp combination and it was obvious the amplification didn't have the juice to control and offer punch for the speaker's bottom end but I figured I had the amps to do the job at home. I also use very fast and transparent Nordost SPM cables which seem to match very well. As with the Kappa 9s then, having sufficiently powerful amplification (and the rest of the equipment chain) of the highest quality is critical. I'd suggest not considering these speakers otherwise.

Overall, I'm very very happy with the speakers. I was unsure if they really would provide a signifincant upgrade to the Kappa 9s given how much I loved those and the quality they offered, but thankfully, the Sigmas really are a big step-up and offer superb all round performance of the highest audiophile reference standard. Just make sure the rest of your system can deliver the goods to make the most of them and you have the room to accomodate them!

Strengths:
Superb transparency and detail from superb EMIT and EMIMs coupled real bass depth and solidity. Superb driver integration and overall coherance offer very natural presentation. Great build and finish. Planar-like soundstaging. A genuine reference standard loudspeaker.

Weaknesses:
To be expected with this type of speaker - very very heavy and large. Require space around them to perform optimally. Very power/current hungry. Unforgiving of system shortcomings.

Similar Products Used:
ProAc Response 3; Apogee Stage; Magnaplaner 2.5R; Apogee Duetta Signatures; Perigee FK-1; Yamaha NS1000M; Infinity RSIIIA; Inifinity Modulus; Infinity Kappa 5. Infinity Kappa 9

Price Paid:  $1300.00 from J Robert Barry

Summary:
INFINITY REFERENCE STANDARD II. Tower speakers 1981
limited production .2 10" woofers' 3 5'mids.2 emit tweeters.1 Sound & soundstage amazing. Solid bass one of woofers is crossed over as sub woofer. great extended highs. Beautifully built solid oak defraction wing, separate part of enclosure for woofers. powered by 400 watt Acurus (4 ohm speakers) power amp with cx2 yami preamp. KNOCK your socks off sound.

Strengths:
great sound, sound stage.

Weaknesses:
no longer made. Infinity is not infinity any more. Woofer surrounds shoud have been rubber like on Mids

Similar Products Used:
started with University 2 ways (1960) KLh 6
Jensen 3 ways, Ar 2ax. Ar 3a.(BETTER but missing something) ADS 810 (too bright) Now for more than 20 years Infinity's( perfect)
Had to refoam surrounds

Price Paid:  $1000.00 from Dutch Import agency

Summary:
This is about the Infinity IRS OMEGA, not the Epsilons. (There is no section for these.) I was lucky to purchase a pair of Omega's for a very low price.
This is about my first experience, since I am not using them for a long time and they really need a long time to break in. What can I say? Well , They sure are marvellous in every way. Great dynamics, very real sounding voices and sheer musicality overall. I'm impressed. I'll write more about them later.

Strengths:
Very open sounding, electrostatic-like sound (But with more bass than any electrostatic will ever be albe to produce.) The feeling of a live concert in Your own home.

Weaknesses:
You need some really good equipment to drive this babies. A lot of power is also welcome since efficiency is and imedance are low. Don't use cheap tranny-stuff!!!

Similar Products Used:
Infinity Overture, Prelude MTS, etc.

Price Paid:  $0.00

Summary:
Excellent sound!!!

Price Paid:  $0.00

Summary:
(continued from below)

...last bit of servo gain. But not now - I'm very happy with the sound. BTW, don't try any inductive devices anywhere in the woofer/ servo/ amp loop to try to keep the ring out - it will shift the phase out of sync which makes the ringing much worse. The extreme of this effect is having the phase switch set wrong and being 180 degrees out of sync turns the servo circuit from a corrective one into a destructive one.

I plugged in the Rev A unit to see if it performed better. First impressions were "yes." The servo roar was quieter, and I could dial in more gain on the pot in the back when set correctly (about -1dB versus -4dB on my original version). I expected that this apparently better performing circuit would yield better sound, but I was wrong. First off, my bass level needed setting much higher than the original version (+5.5dB versus +2.5dB) to get the same deep bass volume I'm used to. But this setting sounded too high in the mid and upper bass - too "thick." What I love about the Epsilon's bass is that it's tight, linear, perfectly pitched, and can go low enough to give you chills. To get chills out of this Rev A unit, I had to set the level too high, such that it ruined the other qualities.

Back in the box goes the Rev A, waiting for emergencies or some future knowledge of something I can do with this circuit. My theory is that the Epsilons were so unreasonably demanding for those who under-powered the woofers, or expect too much, that on the Rev A they tightened the boundaries and maybe cleaned up a little of the circuit. This made it behave better for customers, but in my opinion it sounds like it's been neutered. My Bryston 4B-ST keeps up very nicely.

If there is anyone out there who has knowledge about the Epsilon system and its SCU; I would love to hear from you. I suspect I can tweak a little better more out of this wonderful speaker system.

Chris Seymour
Cseymour@watlow.com
Seymour@elknet.net

Weaknesses:
having to split my review into 2

Similar Products Used:
My system:
Infinity IRS Epsilon fronts
Infinity Renaissance 80 rears
Cary SLM-100 tube monoblocks
Bryston 4B-ST THX woofer amp
Harman Kardon Signature 2.0 6-channel preamp/ processor
Rega Planar