Axiom Home Page Forums General Discussion Home Theater Avia Disc & Sub-Woofer Calibration...

Wid,

I read Alan's article. You did not misquote it. Alan is incorrect in his statement.

I am sincerely sorry for having invited discord. My intent was not to create controversy over analysis of the M80 response curves. By using "60-80Hz" instead of "40-80Hz" in my example, I suppose all of this could have been avoided while still conveying the core issue.

For the sake of discussion, let's assume that a large front speaker (like M60 or M80) is capable of producing FLAT response down to 60Hz. Let's also assume that you have a big, honkin' amplifier so that the notion of relieving the amp of the 60-80Hz load is moot.

Other than enabling more amp headroom, are there ANY benefits of crossing over the mains at 80Hz rather than 60Hz?

Intuitively, I would think you would want the mains to play as low as they are capable of as long as you could provide adequate current.

The only reason is the placement of the main speakers. For example, until I piled up a whole bunch of boxes of paperback books in a corner of my room, even setting the M80 at 80hz was problematic (terrible booms). Now that I lessened one of my "corner problems", I can go down to 50hz with only a small range of boomy notes (noticeable mainly with pipe organ) near 40hz. Setting the xover at 60hz provides a very good bass distribution accross the whole room, better than at 80hz. A lot of these choices depends on placement.

The M80s alone have really good bass. Before I received by new HT unit, which forced me to put the M80s much closer to corners, the bass was astonishing, even for the 2 months I waited to buy my EP500.

I'm sure Alan will be along to confirm who is truely incorrect.

Hitting on Eric's comment, I think maybe the reason I've lucked out and our room sounded decent from jumpstreet (re: Mike's question regarding why screw with anything) is that I set the speakers up according to the Rives suggestion of the 1/5th room placement, in other words I have my 80s set 5' off of the front wall in a 25' long room. Whenever I had them fairly tight to the wall they sounded a bit boomy but after they were moved way back the bass seemed to have tightened up quite a bit, which makes me believe that room and room placement makes a huge difference ... probably more so than is given credit for at times.

Which also makes me believe that there can be no one set procedure for setting these systems up due to the numerous room layouts these speakers are going in, comes back to that personal preference thing I suppose.

BTW, for *my* particular room and taste I did set the 80's back to a small setting and the crossover back to 60 after trying the large and LFE setting on our AVR for a day.

<slaps forehead> The Room! Of course!

Eric and Rick, thank you!