BIC Acoustech HT-75s WILL NOT IMAGE no matter what, help!

Adam Smith · 10-10-2006, 12:31 PM

I've had this setup in my living room for quite a while now and no matter WHAT I do I cannot get a clear "picture" of the music I'm listening to. I can still tell where each speaker is coming from and they basically sound somewhat out of phase. I have double checked the polarity coming from my receiver. Here is my setup:

Denon AVR-1082
Optical input from Chaintech AV-710 in HTPC
12 gauge wire to BIC Acoustech HT-75s
14' wide by 18' long, left-wall-open living room

I put on the 1999 IASCA test disc this morning and listened to the polarity/phasing track multiple times. Neither sound completely right, but the "out of phase" is notably worse. Imaging gets slightly better when I sit in between the speakers (I'm sure I look like a moron listening to a girl talk over and over sitting in my living room between my two front channels..) but it is definitely not anywhere near what I expect. I have (freebie) KLH 9250B's in my room attached to the multi-zone output of the Denon receiver and even those image better.. and the midranges on the KLHs have been replaced with a Pioneer car audio 2-way because one was blown..

I'm totally at a loss. The frequency response of the HT-75s is amazing and even with NO audio image whatsoever I still don't mind how they sound but it's REALLY bugging me why they aren't producing an image.

DTS-encoded audio sounds nice, as do movies.

grrrrrrrrrrrrr! Any suggestions?

Jack Gilvey · 10-10-2006, 02:30 PM

I know nothing of those speakers, but reflections (particularly from sidewalls) can kill an image in its tracks. Where are they situated?

LanceJ · 10-10-2006, 04:24 PM

I've read numerous times where individual tweeters/mids/woofers were discovered to be wired incorrectly inside the cabinet at the factory. And these weren't just the "cheap" brands either.

Out-of-phase woofers are easy to spot since lack of low bass is very noticeable (just face the speakers at each other, about 6" apart & play some bass heavy music. Then switch the +/- wires & listen again). Mids and tweeters are trickier though. Usually you'll get this blurry, floaty or "inside your head" effect when standing in front of the two speakers.

BTW: not to sound like a jerk, but these speakers *may* just not be designed well enough to image properly in the first place. Though sometimes a speaker engineer may intentionally include a slightly out-of-phase condition which makes the resulting sound seem less analytical.

Chu Gai · 10-11-2006, 06:20 AM

How are the speakers set up in the room? Can you draw a picture? Also, I take it you've got an SPL meter and have calibrated?

timZa · 10-12-2006, 01:30 AM

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Adam Smith · 10-12-2006, 05:32 PM

I'm still waiting on my EOS-350d to arrive so here are some absolutely terrible camera phone pictures of their current locations. Moving them around doesn't seem to change too much.

Calibrated? I what? I've never done any EQing.

The speakers not being designed well enough to properly image is a possibility, but I have heard $3 computer speakers that image better. Actually, I don't think I've heard anything worse..

For instrumentals and beats where imaging isn't as important, these speakers sound really nice. As soon as someone sings or an attempt is made at making a sound stage, things kind of fall apart.

It seriously sounds like they're out of phase both ways. >_<

Arthur S · 10-12-2006, 07:40 PM

Adam

Can you take off the grill (covers)?

Adam Smith · 10-12-2006, 11:02 PM

Yes, I did about forty minutes ago. They got slightly brighter but the problem remained. I just spent about twenty minutes objectively listening to the speakers, with my ears directly on axis from the tweeters, with the speakers at an approximate 25 degree angle from parallel. There is definitely something wrong. For comparison, I switched the two Acoustech HT-75 fronts with my KLH 9250B's in the same position (the ghetto ones with the Pioneer 2-way midrange) and what can I say, wow, a huge difference. One of the tracks that surprised me the most was Melissa Etheridge's "Like The Way I Do" (don't even start.. I like that song :]). I can pinpoint her voice, somewhere about 10 degrees to the right of center, from where I was sitting.

One other thing I noticed with the HT-75s is that the tweeters sounded .. different. I can't put my finger on it, but with my ear up to each tweeter the right one seems to have more high-end treble. I have no idea why. It's not huge but I'm speculating that could be at least part of the problem.

I can't believe I'm favoring KLHs over these. The KLHs have overdone, muddy, boomy bass, and the midrange isn't anything to be proud of (low end Pioneer car audio 4" speakers.. ew, especially inside KLHs!), but the speakers sound uniform and ..

Wow. What gives?

Arthur S · 10-13-2006, 07:30 AM

Adam

You would be surprised that even $10,000 pair of speakers will have slightly different FR. Sometimes 2-3 db difference between right and left.

The reason I asked about the grills is because some people have achieved better imaging by surrounding the tweeter (and perhaps midrange) with felt. Felt reduces diffraction effects from the cabinet edges.

I don't know if it would help your your speakers, they may be miswired internally, or could be some design issue. Still, if you got ahold of some felt you could lay it around the drivers and tape it down to see if it helped. If it did you would want a more secure way of holding it. If it didn't, you wouldn't be out much money and you just take the felt off.

Chu Gai · 10-13-2006, 01:21 PM

Is there a reason you can't move them out a bit more and in a little closer?