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critical listening - i hear something i don't like

i need some help. I've been around this high end audio and theater thing for a while...but am just finally getting MY system close to the point where i really want to listen to it. I just upgraded a few components and actually (finally)hear 'air' in a movie i was watching this past week. The entire front collection of speakers dissappeared. WOW!.. getting very close to something good.. okay..enough background...

Here's what i need help with. In between these episodes of marvelous listening, when the movie track gets loud, the sound appears incoherent. There are three things i'm guessing i could attribute this to: 1.) the amp speaker relationship - either the speakers can't take the signal output by the amp, or the amp can't keep up with the signal. 2.) my room really does need some anti-reflective treatments - I have stuff in the corners.. but the side walls are bare (rectangular,sealed room, carpeted floor) 3.) the digital cable between DVD and PrePro may need some more thought

Any thoughts on where to focus my efforts? i explicitly didn't include a system description because i don't want to get into equipment conversations yet. If this thread gets interesting, i'll do that next

thanx in advance
objective1
objective1 OP
95 posts
 
np.. no tears here... :-) just looking for some objective help... trying to focus my plans
newbee
4,751 posts
 
In defense of Ohala, you can't comment intelligently on this type of question with out details. For instance, room dimensions, speaker placement, speaker type, amp type, decible level when sound starts to distort, etc. Here is a WAG, you are overdriving speakers to sound pressure levels neither your room nor your speakers were designed to handle.
nighthawk
259 posts
 
Sounds like too much room reverb. Get a copy of F. Alton Everest's Master Handbook of Acoustics and do an RT60 analysis of your room. (It's easy, trust me.) This will tell you what frequencies are problematic and will help you determine what type of absorptive material will work best, and where to put it, to smooth out the response.
rives
953 posts
 
First, I should say with so little information, my comment may not apply--but it well could. Almost any system can "outplay" the room. As you turn it up the energy held in the room is too great relative to the direct sound--the result is a loss of coherency. When we design rooms, we need to know how load a person will play their system and the room must be designed to properly relieve that energy--I say properly, because it can't just be leaked--it has to be disappated appropriately. My guess is that you are simply outplaying the room (by the way this occurs and is actually much easier to detect on 2 channel systems). High SPLs for HT require much pressure release. THX specifies rooms above 110db (that's really loud in my opinion). I don't listen to movies that loud--but many of our clients do, and we have to design the room with that in mind.
ohlala
1,234 posts
 
Responders are the the ones who are "postulating" in my post. Sorry for the ambiguity.

A more powerful conclusion will result in discovering first hand the cause to your problem instead of relying on present or past responses. I would be surprised if lack room treatment is not partly or totally the cause because the room's sonic affect increases with volume and a "poorer" room commonly results in what you described. Because you are addressing the room already, you can soon eliminate it as a confound or, hopefully, eliminate the problem.
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