Powering Infinity Prelude MTS

Hi Joysjane, thanks for the heads up re the woofer and tweeter. I don't think it's an amplification issue as I can hear a slight scraping sound when I push the particular mid-range and woofer manually with my thumb(with no music playing) to simulate an excursion. There is no scraping with the other drivers.

Where did you source the mid-range unit from last year?

No, I have never tried hooking the pre-amp direct to the woofer. I use these speakers as a secondary system and therefore haven't experimented with them much in the year and a half or so that I've owned them. One thing I haven't been able to nail perfectly with regards to speaker positioning is image stability and focus - my PMC speakers always seem to 'lock' vocals more tightly between the speakers than the Preludes - do you toe in your speakers, and if so, at what angle from the listening position? Also, how far away have you kept them from the back walls?

Yep, definitely the voice coil.
What I meant by amplification was that people were pushing the Preludes too hard with lesser amps and ending up damaging the voice coils. Mostly folks with receivers.
You wouldn't have that issue with your amps.
I didn't mean that it was your amp that was the problem.

I was lucky enough to catch Harman at the beginning of last year when they happened to have gotten some midrange drivers in.
I was on a list to have them contact me if they had gotten some in stock.

Harman said they (MTS' Midrange Drivers) won't be available through them anymore.
I still keep contacting them just in case.

Once in a while you can find someone selling them on ebay.

I do have mine toed in. They're focused about 3' behind my listening position.
I've had the best luck with them 4' from the rear wall and 3' from the side walls.
I'm 10' from the speakers and they're spaced about 10' apart.

How are your speakers set up from your listening position? Distance, width, toed?
Have you experimented much with different placement?

They're sweet speakers!!!

Agree these are very beautiful speakers. I drive mine with 12 watt Wavelength Cardinal 300B monoblocks, and haven't had voice-coil failure. I don't have them toed-in.

For owners that have had problems, it's a shame that Harman Kardon doesn't provide better parts support.

I have done very little experimentation thus far with these speakers as I haven't had the chance to use them much. I originally set them up almost face forward and about three feet from the back wall. I later tried toeing them in significantly and pushing them back closer to the wall, which resulted in a smaller but more precise and focused sound-stage. I have also only applied RABOS only once, before I adjusted their positioning, so I need to do that again at some point. The volume control of one of the woofers has come off, which I will have to get fixed - yes, the QC issues are a bit tiresome. I'll probably spend more time experimenting with them one of these weekends.

Agree that these are very good speakers in a number of ways, especially for use with lower power amps. They are a bargain used - a very neutral speaker with innovative design features for relatively little money on the used market.

Did you know that the Infinity RABOS website has a calculator that computes the settings when you input the meter readings?

The RABOS means that the distance from the back wall isn't critical. I recommend no toe-in. The listening position should make a close triangle with the distance between the towers, e.g., if towers are 7' feet apart, then your ears should be circa 8' back from the center point between the towers.

I doubt that the volume knob was a QC issue. Are you the first owner?