[bjs10]

I'm using a Denon 4800, and it clearly sounds better in stereo mode than in surround. The amplifier section is rated at 125W/channel with all 5 channels driven, and 165W/channel with only two. So my first instinct is to say that the extra power is what's helping. But, the THD also drops when placed in stereo, from .7% to something like .1% (can't remember the exact number). My speakers are 91db efficient, and I don't listen at ear-splitting levels, usually around the -20db level according to the Denon. So maybe it's the lower distortion that sounds better? I'm planning on buying another amp, but I don't want to pay for 200W/channel if 100W will give me the sound I'm looking for. Do I need the extra power, or just an amp with less distortion?

 

[ptaaty]

I don't know that you need more power or less distortion (although it is always good!).


I am questioning how you can possibly make a comparison between stereo and surround on the basis of distortion at a relatively low level.


If you are listening to music, the difference is most likely because when the receiver is put in surround mode, in undergoes extensive processing and the sound intended for two speakers is matrixed and rebalanced between speakers. So the sound coming from your main fronts will sound totally different and, by themselves, much worse compared to stereo.


Forgive me if I am speaking below you, I just noticed you were a newer member and am unsure of you knowledge.

 

[fatbottom]

Are you downmixing multi-channel Dolby Digital/DTS audio to stereo? If so that explains it.


Or are you playing back a CD (2 channel PCM) in stereo direct -you prefer that, then switch to a DSP mode such as rock?

 

[bjs10]

Sorry, should have given a little more info. There's quite a difference not only on PCM audio but between PCM and DD/DTS. Let me explain that a little better: if I'm listening to a CD or satellite music channel, and switch to stereo, I get a much improved sound. Bigger soundstage, smoother highs and midrange, a general improvement. This could be explained by the lack of surround processing of a 2-channel source. But watching DVD in DD/DTS 5.1 still doesn't sound as good as a stereo source sounds in stereo. I know this is an apples-to-oranges comparison, but I don't think that PCM stereo is innately superior to DD or DTS, at least not enough to justify the difference I'm hearing. Anyway, I'm going to try some 200W monoblocks. I will report my findings.

 

[fatbottom]

Well DD & DTS are compressed audio streams. PCM is not.


Try playing back a DD 2 channel mix, and compared against the 2ch PCM (ie a music DVD)

 

[M Code]

Quote:

Originally posted by bjs10 Sorry, should have given a little more info. There's quite a difference not only on PCM audio but between PCM and DD/DTS. Let me explain that a little better: if I'm listening to a CD or satellite music channel, and switch to stereo, I get a much improved sound. Bigger soundstage, smoother highs and midrange, a general improvement. This could be explained by the lack of surround processing of a 2-channel source. But watching DVD in DD/DTS 5.1 still doesn't sound as good as a stereo source sounds in stereo. I know this is an apples-to-oranges comparison, but I don't think that PCM stereo is innately superior to DD or DTS, at least not enough to justify the difference I'm hearing. Anyway, I'm going to try some 200W monoblocks. I will report my findings.

What you are explaining does make sense...

Sonic quality could be better in the Direct mode as whenever one is processing multichannel (DD or DTS) as due to the DSP resources and gain structure used for surround processing something could be left behind. Regarding PCM digital sources, since these are full bandwidth without compression they should sound more open and transparent, and if they are higher resolution like 96KHZ or SACD they can sound superb..