Question on Surround Modes, Dolby Digital, and DSP

belloc · 01-02-07, 03:16 AM

I have just set up my first home theater, a fairly low-end system, but adequate for my needs. Here are the relevant parts: Denon AVR-587 receiver, Polk Audio RM-6750 speaker package (two small fronts, a small center, two small surrounds, and a sub), a four-ish year old Zenith DVD/VCR, and a DirecTV HD receiver (H20-100).

Audio is connected from both the DVD player and from D* H20 STB to the Denon AVR via digital optical toslink cables.

My question is about surround modes from different sources, and how the Denon deals with them.

When I select INPUT MODE as "AUTO", and then select "STANDARD (Dolby/DTS Surround)" as the surround mode, I get varying sound output results, depending on the source.

Here's what I mean: for example, watching a DVD of the TV show "24", sound comes out of the two front speakers, the center, and the sub, but I get no sound from the surround speakers at all. Then, watching a DVD of "Superman Returns" (without changing anything on the receiver), I get a very nice surround experience with sound from all five satellites plus the sub.

Again, watching "Sportscenter" on ESPN-HD in the same surround mode (again, without changing anything on the receiver) it sounds like only the center channel is producing sound during the newscast, and then when they show highlights of a football game or something, the front speakers add some crowd noise and things, but again nothing comes from the surrounds at all. But watching Discovery Home Theater (on DiscoveryHD), I again get a full surround experience.

So, with the varying sources producing varying results, I guess the sources are feeding the receiver varying sorts of audio information. But (for example) the DVD box for "24" says that its sound format is "English 5.1 Dolby Surround", so shouldn't I be getting full surround from that? Also, ESPN says Sportscenter is in "Digital Dolby 5.1" on ESPN-HD, so why such limited sound there?

Incidentally, if I switch my surround mode from "Dolby" to "5CH STEREO" (which is a Denon DSP surround simulation), I get the full five channel surround, but isn't that just faking it? Why am I not getting full surround with the Dolby Digital setting on the receiver for those programs that ought to have it?

I hope my setup and question makes sense. Thanks.

belloc · 01-02-07, 02:25 PM

I just realized I probably posted this in the wrong forum. Reposting over in "Amps, Receivers and Processors". Sorry, mods.

01-02-07, 03:16 AM	#1 \| Link	<a href='http://rev.avsforum.com/phpAdsNew/adclick.php?n=a4ac4393' target='_blank'><img src='http://rev.avsforum.com/phpAdsNew/adview.php?what=zone:30&n=a4ac4393' border='0' alt=''></a>
belloc New Member Join Date: Dec 2006 Posts: 8	Question on Surround Modes, Dolby Digital, and DSP I have just set up my first home theater, a fairly low-end system, but adequate for my needs. Here are the relevant parts: Denon AVR-587 receiver, Polk Audio RM-6750 speaker package (two small fronts, a small center, two small surrounds, and a sub), a four-ish year old Zenith DVD/VCR, and a DirecTV HD receiver (H20-100). Audio is connected from both the DVD player and from D* H20 STB to the Denon AVR via digital optical toslink cables. My question is about surround modes from different sources, and how the Denon deals with them. When I select INPUT MODE as "AUTO", and then select "STANDARD (Dolby/DTS Surround)" as the surround mode, I get varying sound output results, depending on the source. Here's what I mean: for example, watching a DVD of the TV show "24", sound comes out of the two front speakers, the center, and the sub, but I get no sound from the surround speakers at all. Then, watching a DVD of "Superman Returns" (without changing anything on the receiver), I get a very nice surround experience with sound from all five satellites plus the sub. Again, watching "Sportscenter" on ESPN-HD in the same surround mode (again, without changing anything on the receiver) it sounds like only the center channel is producing sound during the newscast, and then when they show highlights of a football game or something, the front speakers add some crowd noise and things, but again nothing comes from the surrounds at all. But watching Discovery Home Theater (on DiscoveryHD), I again get a full surround experience. So, with the varying sources producing varying results, I guess the sources are feeding the receiver varying sorts of audio information. But (for example) the DVD box for "24" says that its sound format is "English 5.1 Dolby Surround", so shouldn't I be getting full surround from that? Also, ESPN says Sportscenter is in "Digital Dolby 5.1" on ESPN-HD, so why such limited sound there? Incidentally, if I switch my surround mode from "Dolby" to "5CH STEREO" (which is a Denon DSP surround simulation), I get the full five channel surround, but isn't that just faking it? Why am I not getting full surround with the Dolby Digital setting on the receiver for those programs that ought to have it? I hope my setup and question makes sense. Thanks.

01-02-07, 02:25 PM	#2 \| Link
belloc New Member Join Date: Dec 2006 Posts: 8	I just realized I probably posted this in the wrong forum. Reposting over in "Amps, Receivers and Processors". Sorry, mods.