Expanding 5.1 to 7.1 or 5.1.2?

[Ibrewster]

I currently have a 5.1 surround sound system on which I am upgrading the AV Receiver. The new receiver is a Denon AVR-S920W unit which is capable of 7.2 channel output. As I do have a couple of extra speakers lying around from an older system (just a couple of small, 8-ohm satellite speakers), I was thinking I might as well connect up the last two channels as well.

In looking at the Denon manual, it would appear I have a plethora of options available to me as to how to configure those last two speakers: Surround Back L/R, Front height L/R, Top Front L/R, Top Middle L/R or Dolby Atmos L/R (front or back, apparently). Given the physical layout of the room, I believe that pretty much any of the options are doable, perhaps other than the atmos back option - I have wall/ceiling mounts for the speakers which should allow me to mount them pretty much anywhere, pointed pretty much anywhere. Ceiling is a standard 8' height, nothing fancy.

My question is what are the pros and cons of each option? I am clueless when it comes to audio layout, I just want it to sound good . Am I likely to get more pleasing results from one layout than from another? In terms of audio source, the primary source will probably be an AppleTV, with a Sony 4K blu-ray player being second, although perhaps more important in terms of wanting best sound quality, if source makes a difference.

 

[lovinthehd]

When I first went with 7ch I had enough speakers to try both front height and rear surrounds at the same time (depending what sound mode I chose), and in that room went with rear surrounds after some experimentation. Haven't tried the Atmos type positions, my avr doesn't support that. Currently using 9ch with both front wides and rear surrounds in my main room (different house than when I went from 5 to 7).

Since you can try all the options, do some experimenting to see what you like.....

 

[Ibrewster]

Well, that would make sense, except I'm not sure how I would mount a speaker to the ceiling to "try" it without making holes in said ceiling, and once I've made holes I'm not going to want to move it Maybe I can rig up some sort of temporary support though. I'll have to think about that.

 

[lovinthehd]

Well, that would make sense, except I'm not sure how I would mount a speaker to the ceiling to "try" it without making holes in said ceiling, and once I've made holes I'm not going to want to move it Maybe I can rig up some sort of temporary support though. I'll have to think about that.

There's always patching the holes....but you can try the others more easily first. Curious, what are the dimensions of your room?

 

[Ibrewster]

Total room or listening area? The "listening area" is only about 10'x14'. Basically just one corner of a room that is roughly 30'x40' or the like. So I have the 5.1 setup with the TV and front speakers spaced along 10' of one wall, with the seating area about 14' back, surround sound speakers on either side of the seats. Hopefully that makes sense.

Yeah, there is always patching holes, I just don't like the idea, especially considering that the ceiling is still new

 

[lovinthehd]

One reason I didn't go with an Atmos avr last time was I'm not messing with my ceiling, too much work to set them up there...

That's a smallish listening area for a 7ch system, in something that size 5 works well enough. Maybe the ceiling option. Probably not enough room for rear surrounds depending where your seating is.

The full room size is harder on subs, as they "see" the whole space, whereas your speakers are more about the distance between the speaker and your seat.

 

[Ibrewster]

Gotcha. Yeah, I was just thinking "well, I've got the speakers, and I've got the channels..." So maybe just go with the top-middle option (as you said, the ceiling option) to provide some vertical sound separation (should I ever play something that has that data), since the 5 system provides plenty of sound to fill the space.

 

[William Lemmerhirt]

Agree. That space is pretty small for 7.1. Should have a round 5' behind the LP for rear surrounds. I would go with 5.1.2 of your choices but if you could swing it 5.1.4 is a better choice yet. Another question is, the 30x40. Is your listening area open to all that? If it USC I'd be looking at subwoofer upgrades. What do you have for speakers?

 

[Ibrewster]

The Denon AVR-S920W only has 7 channels, so 5.2.2 is going to be the best I can get - no .4 option For speakers, it's nothing impressive - basically, scavenged leftovers. The front and surround sound speakers I'm using are Panasonic SB-FS900's, with a panasonic SB-PC701 center. For a subwoofer, I'm planning to pipe the subwoofer out of the Denon to my logitech Z906 system (with no speakers connected), if it works (seems like it should), until I can better afford a *real* subwoofer. The satellite speakers from the logitech system are what I am planning to use to add the height channels. How's that for a jury-rigged mish-mash?

Yes, the listening area is open to the full space, I just don't care about filling the entire area with sound. Subwoofer - and speaker - upgrades are DEFINITLY on my to-do list (sooner rather than later, accepting recommendations ), but the receiver upgrade was higher priority to get rid of my current rats nest of HDMI and audio switches. Oh, you want to watch a DVD? Sure! Just set the TV to HDMI 2, the HDMI switch to input 1, the optical audio switch to input 3, and the sound system to input 4. Or was it the sound system needs input 3 and the optical audio switch needs input 2? Gah!!!

 

[lovinthehd]

That little sub won't do a lot in nearly 10,000 cubic feet....

Try this article http://www.audioholics.com/loudspeaker-design/subwoofer-room-size

 

[Ibrewster]

Interesting read. So, if I'm understanding things correctly, getting a good bass response from a subwoofer is more a function of total volume than distance from the subwoofer - as the total volume gets larger, the perceived output from the subwoofer at any given point drops off. At least, that seems to be the implication here. I guess that does make some sense, given that in an enclosed area the sound waves can bounce off the various walls and fill the area better.

I would have thought the "room size" to work with would just be the area I want to have "good" sound, that is around 1,200 cubic feet. But I guess that just shows how little I know about acoustics

 

[lovinthehd]

Interesting read. So, if I'm understanding things correctly, getting a good bass response from a subwoofer is more a function of total volume than distance from the subwoofer - as the total volume gets larger, the perceived output from the subwoofer at any given point drops off. At least, that seems to be the implication here. I guess that does make some sense, given that in an enclosed area the sound waves can bounce off the various walls and fill the area better.

I would have thought the "room size" to work with would just be the area I want to have "good" sound, that is around 1,200 cubic feet. But I guess that just shows how little I know about acoustics

Sort of. Try this on the Schroeder Frequency https://www.soundandvision.com/content/schroeder-frequency-show-and-tell-part-1

 

[Ibrewster]

Thanks. I think that makes more sense now. Sort of sounds like I need to a) aim large when selecting a sub, and b) seriously consider getting a second one as well and making use of that second sub output on the AV Switch