Help with Infinity IRS speakers.

I write to you because i cannot figure out what causes me a problem in the high frequency (trebble) range.

Few weeks away i bought a pair of brand new INFINITY IRS OMEGA.
I thought I made a very good deal because those were the very last speakers of the IRS series equipped with the true and reknown EMIM et EMIT medium and tweeters, also they were sold quite cheap (around USD $3000 a pair). I saw later that those speakers were heavily price promoted mainly because they were in the inventory of Harman France since over two years (ex-factory
March 99).

First I quickly found out that one of the boomers was not fully connected: those speakers have a double circuit and only one was soldered which caused one speaker to sound with a lot less bass than the other : that was quickly solved . Anyway this incident demontrated that the speakers had not been checked before packing.

After a while I discovered there was some distortions in one of the mediums. When carefully checking the EMIM medium speaker I realised the magnetic bars were corroded (or something like that) and that some magnetic particules (even magnetic powder) were laying against the ribbon . I opened the faulty EMIM speaker, and cleaned the magnets very carefully . After that little
cleaning all distorsions went away. Excellent, i thought, my troubles have ended !

But no !

Now , after some more weeks of listening i realize there is also -from time to time- a distortion in the trebbles on both speakers. It happens on some peaks of cymbals for instance. Not on all recordings, but always on the same signal.

However I cannot make up my mind about what causes this desagreable slightly distorted sound.

Could it be :

- the EMIT technology itself which causes sometimes some distorsions under certain circumstances.
- the EMIT technology that makes the sound a lot more transparent and therefore let me hear some distorsions coming from the rest of the system or from the CD itself. ( I had electrostatics before so that should not be the case as I was used to a very transparent sound in the trebble zone.)
- The Emit tweeters that are corroded the way the EMIM medium was ? (I cant see anything and would not like to play the surgeon again)
- The crossover : could it be affected by inventoty aging ?
I suspect again the bad inventory conditions at Harman to have caused this .
If ever you experienced the same trouble with your IRS Infinity speakers or if you have any hypothesis to share with me, please be kind enough to e-mail me with your recommendations.
I look forward for your help.

Well, you didn't mention what amplifier you are using or how loud you like to play the speakers. If the speakers seem to be distorting on loud peaks you could be overdriving your amp. If you turn the level down does it still distort on the same spots? Also, you didn't mention your source -- if it's an analog turntable, perhaps there is something wrong with the cartridge setup or phono preamp interface. Tell us more about your associated equipment.
I'll second all that Plato said, and add my experience.
As an owner of IRS Beta's, I feel your pain.

Your room: Is it well treated? These speakers like a BIG room to sound their best, otherwise, you'll need to turn down the crossover controls to or near to their minimum points. My Beta's are in a room 16 feet by 19 feet. I use solid state, Levinson amps with the Betas, and my mid, lower and upper tweeter controls are just off the lowest setting on the crossover.

Tube amplification: I am not entirely familiar with the Omega, can you biamp them? If so, borrow a good tube amp from your friend, a dealer, whatever and try it on the mid/tweeter side. This may make a world of difference.

I use a Levinson 333 on the mids/tweets of my Betas. This amp was known for a darker, subdued sound, even so, it's still not as good as tubes would be!

Your other equipment: Your Omegas will show flaws in cableing, harshness in your CD player, and ALL the flaws Redbook CD's can have, however on/with good sources/components, very little that's currently available at any price will outdo your Omegas.

Hope this helps!

The INFINITY IRS OMEGA speakers are basically the same speakers as the Infinity Sigma speakers.
My system consists in the following :
Vinyl is Mitchell Gyrodec+SME IV + Benz L0.4
CD is krell KSP 30i
preamp is krell KRC 3
Amps are alternatively Krell KSA 50S (class A) or KAV 150i (class AB) because here in France it can be hot, as it is today , when summer comes. And the KSA heats a bit too much my small (12 sqm) listening room. All inter-links are Fadel cable, balanced , speakers single wired only with transparent audio wave 100.
Your Omega's are underpowered with either of those Krell amps. No offense, but your gear list suggests a recipe for trouble with these speakers, trouble in the way of brightness and low-power. Be careful at louder levels, as replacement parts will be hard to come by.

I believe Paul is correct about your particular Krell amps being underpowered for those speakers. When played even at moderately loud levels there would probably be a lot of clipping. See if you can try an amp that is more powerful and very stable when driving low impedance loads -- I believe those Omegas' impedance dips a bit low at certain frequencies.
If what was said in the two follow ups is true, you should think about getting a solid state amp with some muscle to power your speakers up. I have read about several people with Infinity Kappa 9s, which are very power hungry running them with ARAGON amps. They had recommended the ARAGON 4004 or better, the 8008, which can be easily found in this, the voltage in France is a little different issue. Still, a good thing to try more power...I have the Kappa 9s, and they do seem to distort under low power...Kappa 9s have SEMIT and EMIT tweeters, which sound rather glaring and crisp when asked to be driven very high, as you describe in the Cymbals.