Random Stuff About Surround Sound

[MagnumX]

I have a 5.0 system because that is all I have space for, I can't even fit a sub in.

I didn't think I could fit more than 6.1 in that room due to the sliding door in the back so close to the wall, half-bathroom and fireplace plus it's not wide enough to accommodate 3 side-by-side chairs and still put speakers to the sides. I had a 6.1 system for 12 years and then I started experimenting with a set of front heights when I read that Yamaha AVRs had a "dialog lift" feature for many years and I found my existing AVR already had it (and frankly the rear center speaker wasn't used for much and often sounded "in front of me" due to a psychoacoustic phenomena so I could use them instead and it would switch at a button if I needed the rear channel. I just had to try it out so I wired up those bookshelf speakers on the top of the bookshelf.

OMG, what a difference for the Yamaha DSP modes that sounded like little more than just an echo box before. I suddenly had dialog coming directly from the screen (instead of under it) and with the movie theater DSP mode, a mono movie like The Maltese Falcon sounded like I was in a giant old fashioned (not so dampened) movie theater. I was sold on the dialog lift feature, but kind of disappointed it only worked in those DSP modes, all of which seemed desperate to change my room into some other kind of room. The giant room effect was kind of neat, but I didn't want it for newer movies.

That's when I came upon the idea of using a mixer to make my own effect (and that would give me back the rear speaker full time as well). Along the way, I discovered someone made a 7.1 decoder plugin box that could use my 7.1 Input Mode (the AVR had 7.1 speaker support, but it came out before TrueHD and DTS-HD MA so DTS-ES 6.1 was as far as it supported for discrete decoding, but it had a 7.1 input mode for future decoder upgrades. It was pretty cheap (<$100) and so I tried it out with speakers sitting out in the room just to see what it would do. It turned out, it worked pretty well in that little nook before the bathroom and so I used that for awhile.

Then, I read about Atmos and figured, why couldn't I just put another pair of speakers below the existing surround speakers mounted high on the side walls and I'd be set for 5.1.4! But since I was ordering so many speakers on eBay, I found out the PSB X1T speakers were narrower than the T-45 model they were a newer replacement for and it would just fit in that corner without blocking the door (not great against the wall, but the room EQ would help as could sending bass to the sub instead) and there was no reason I couldn't mount the PSB CS-500 speakers on the ceiling (one screw only needed into a joist). The next thing I knew, I had 7.1.6 worth of speakers in the room.

By then I had read about adding extra speakers to an existing 7.1.4 AVR so I went for it. The one I ordered had front wide support too so back to eBay and now it was 9.1.4 (but I could only run 9.1.2 or 7.1.4 at a time). I read about a high-end AVP that added extra speakers using internal mixers and I figured I could use another active mixer to simulate front wides and make it 9.1.6. I also read about "Scatmos" (a term to indicate using Pro Logic decoders to extract a "center" channel from any two signals sent to it, so Front Height Left + Rear Height Left = Top Middle Left and with a 2nd processor, I had support for top middle speakers that sounded discrete. I was at 9.1.6.

I remembered how well those speakers worked in the nook by the bathroom (I had added the towers in the back so they were repurposed) and I found another pair and put them there with another active mixer using side + rear signals and I then have my current 11.1.6 setup. With all the active mixing, it took some tweaking to get the arrayed phantom images to line up right, etc. with where a real speaker would be and aligning the main phantom with the real front height, etc. so everything became "holographic" (It still sounded good with movies along the way). Now, the only thing to do is replace the 11.1 AVR with a 15.1 or better yet a 17.1 (if they ever offer one) to have true discrete 17.1 instead of partial plus mixed arrays and decoded extra channels.

But I never in my life thought I could squeeze 17 speakers and a subwoofer into that room and have them align in any kind of correct pattern, but I guess I was wrong. I've got room for a 2nd sub (could help even bass out for the 2nd/3rd rows a bit better) beside the fireplace (I'd stick that fake fern on top of it and it might not even look bad).

 

[kfbkfb]

http://pspatialudio.com/francinstien.htm^^^
...the position of a high-frequency sound and a low-frequency sound are different.


Does this effect complicate the Involve Audio imaging processing system?


Kirk Bayne

 

[MidiMagic]

If you have a friend walk around you in a circle saying something or humming the entire way, are you seriously telling me you can't flipping hear him when he walks off to your left side because there is no delayed signal coming from a speaker on the other side of you to tell your brain that he's there???? Or does he just turn into a giant wall of blurred pudding when he's talking off to your left? Does that even sound like it makes any kind of logical sense at all? Because I've never heard ANYTHING like that my entire life!

That is different. There are no speakers set in fixed positions. There is one actual sound producer that is moving.

This error occurs only when multiple speakers are being used to provide a panned image between them. In this case, the ears actually find the speaker locations. The standard hearing system cannot without assistance locate a phantom image panned between speakers that are about the same distance from you, but at different angles on one side.

Now I have heard 5.1 (and that would apply also to 4.0) systems that didn't image for *****. Putting the surround speakers on either side of the couch is probably the worst configuration ever conceived. Due to the room, I have a 4.0 system set up like that upstairs with my Carver AL-III ribbon speakers (using Klipsch speakers on the side of the chairs pointed outward to reflect off the side walls). If I run the same demos using that system, there's a bit of a "hole" in the imaging between the Carver speakers and the Klipsch speakers about halfway between them with most material. Put a pair of front wide speakers around 45-55 degrees between them (playing a combination of front + side) and set the levels even and that hole will disappear like magic.

That seems to be assistance. So are the other cases where more speakers are shoved into the gap. You are providing another sound source midway between the sources. It does not entirely remove the cogging, but it makes the cogging steps much smaller and mushier.

Now I'm in no way saying it's not possible some people can't hear that panning correctly due to ear/brain/training/brain tumor, etc., but Dolby wouldn't have even bothered with Atmos or DTS with X if the system didn't work. I have Atmos music albums that place sounds in space a couple of feet in front of me to the left or right in space between me and the front speakers even. It's like a phantom image hologram. I have an Atmos demo ("Silent") where a cart is being pulled from the back of the room straight down the middle of the room to the front of the room and it passes right through me like a ghost wagon.

That's WHY they went from 5.1 to 7.1.

Your hearing system is trained by actual experience. If you have a lot of experience hearing side sounds panned between speakers, then maybe you have developed something that corrects the error.

Since the majority of my listening over 50 years has used a Dolby Surround or PL system, my hearing works best with that kind of position correcting. I was beginning to learn to correct QS when DS replaced it in my main system.

I am not just using one system. I have 3 quad systems using different technology. And most of my experience with discrete 5.1 and 7.1 was in dealer showrooms and in other people's houses. But in all of these cases, I heard cogging when sounds moved along one side. But in some of these cases, I noticed it because I was expecting it.

 

[MagnumX]

This error occurs only when multiple speakers are being used to provide a panned image between them. In this case, the ears actually find the speaker locations.

That simply doesn't happen here and based on the comments on AVS Forums, I think things image pretty well for most people. I'm getting the feeling that it's the lack of delay with old school quad setups to correct for unequal distances (precedent effect pulls image to closer speaker and prevents even panning, leaving "gaps" or really fast movement.

That's WHY they went from 5.1 to 7.1.

Nobody really supported discrete 7.1 but a handful of movies until Atmos came out. Dolby Pro Logic IIx moves through the rear speakers, but unless they're an exact distance to create a circle, it kind of makes a "U" shape instead (Many rooms simply won't allow rear speakers out in the middle of the floor. You almost need a couch pulled away from a wall a fair distance and the speakers behind you, but most significant others don't like that AT ALL. They want the damn couch/chairs back against the wall. You almost need to build a music or movie room. I found it a bit easier to do a circle with the 5.1 half of the room and let the rest do its thing for movies and Atmos. 5.1 with the surrounds behind me images surprisingly well. I just don't get "far away" discrete sounds appearing. It seems limited to a few feet behind me without them.

I am not just using one system. I have 3 quad systems using different technology. And most of my experience with discrete 5.1 and 7.1 was in dealer showrooms and in other people's houses. But in all of these cases, I heard cogging when sounds moved along one side. But in some of these cases, I noticed it because I was expecting it.

I'm betting if you heard my system you wouldn't hear any cogging. Most store/showrooms aren't set up properly, IMO and as I said, I suspect the lack of delay controls to correct for uneven speaker placement front-to-back causes a lot of issues with the older systems.

I just listened for like 6 hours to Atmos and Auro-3D music in a 5.1 + 4 overhead + front wide configuration using half the room. It was a bit like being at Disneyland or hearing a binaural sound effect album. I've been working on lighting effects to go with it so it feels like Disney (have numerous movie props that can light up and the ceiling can light up with stars and moving clouds to look a bit like you're outdoors).

 

[gene_stl]

@MagnumX
Do you have a link to the 5.1 to 7.1 decoder.
This?: Amazon.com: HDMI LPCM 7.1 to Analog Surround Sound Audio Decoder- 4K Version : Electronics

I love the story of your trajectory. That may be the wrong word. It may have been more like sliding down a slippery slope.

 

[MagnumX]

@MagnumX
Do you have a link to the 5.1 to 7.1 decoder.
This?": Amazon.com: HDMI LPCM 7.1 to Analog Surround Sound Audio Decoder- 4K Version : Electronics

I love the story of your trajectory. That may be the wrong word. It may have been more like sliding down a slippery slope.

That looks just like it, yes. Of course, you get no Room EQ Correction, etc., but it let me try out full 7.1 decoding with two dozen titles I owned and with the Atmos demos (as 7.1 base decoding). All it did was speed me towards Atmos. I only used it 6 months or so before I bought an Atmos receiver. What I did first was connect up the front heights with the former surrounds (that were high on the walls and still there as side heights) and run multi-channel stereo mode through just those 4 speakers with some stereo thunderstorm and binaural test CDs just to hear what imaging fully near the ceiling sounded like to see if it was at all believable. Well, binaural thunderstorms through it sounded PERFECT (I think the HRTF data really makes it sound real and binaural with even multi-channel stereo works oddly well on a speaker system (won't get right up to your head with a haircut sound, but does scale upward like the center couch cube and a few feet above is a giant head). Other stereo imaging definitely imaged on/near the ceiling so that's what really convinced me it would work without having to go in-ceiling, etc.

Yeah, I think I wasted some money experimenting (well not a waste for the test value, but I bought more than a few items that didn't work right or didn't get used long term, namely that decoder and some small PLII decoders that didn't work for the "Scatmos" decoding (ended up using Onkyo Pro ES-500 units instead which worked great, except one I got smelled like someone's dank basement and was emitting an audible humming noise (bought another one that didn't smell and is quiet; I couldn't find a single one that still had a working remote).

 

[par4ken]

Did you ever try adding a passive set of front wide speakers using a mere active mixer to lower the angular gap between surrounds (6 instead of 4?). No, I didn't think so. You obviously never tried the "best" setup. Perfect 360 sound without all these cogging issues.

More to the point, you cannot get proper sounds BEHIND you if the surround speakers are directly to your sides. There's no way to get a 360 degree circle and you'll still have imaging problems on the side wall between the mains and side surrounds as that angle is too large. By putting the surrounds at 110 degrees and putting a set of "helper" front wides to lower the angle on the side wall, you get a nice 360 circle, which I can prove with a PS4 game by rotating in a circle (the fireplace roaring or whatever goes in a perfect circle around me with no gaps).

Wrong, Wrong, Wrong again!!!! Why would I bother to muck up my already perfect system for dubious benefit. While I don't think that four speakers are sacred, imaging can be improved with more and more channels but I think that it is unnecessary and impractical in a typical listening room. Further I always insist on having all matching speakers (large) anything else is a bit of a compromise. My system produces 360° pans without problem, you are seated toward the rear of the panned signal not in the exact centre, it sounds damn good. I am still free to sit in the middle of the room if I like, mostly I don't like.
One valid reason for for many adamantly rejecting surround sound is that sound quality is of most importance, adding digital delays and dubious quality speakers here and there is not a recipe for high quality sound.

 

[MagnumX]

Wrong, Wrong, Wrong again!!!!

How old are you?

One valid reason for for many adamantly rejecting surround sound is that sound quality is of most importance, adding digital delays and dubious quality speakers here and there is not a recipe for high quality sound.

Right.... Dolby doesn't know WTF they're doing.

My system produces 360° pans without problem

Don't tell that to MidiMagic as he says that's impossible for all of us.

I'm done talking to you. It's like trying to have a pleasant conversation with someone that's yelling.

 

[par4ken]

How old are you?



Right.... Dolby doesn't know WTF they're doing.



Don't tell that to MidiMagic as he says that's impossible for all of us.

I'm done talking to you. It's like trying to have a pleasant conversation with someone that's yelling.

I am much much older than you. I only yell when people attack my religion. politics or speaker placement. At least we agree about MidiMagic!

 

[MidiMagic]

That simply doesn't happen here and based on the comments on AVS Forums, I think things image pretty well for most people. I'm getting the feeling that it's the lack of delay with old school quad setups to correct for unequal distances (precedent effect pulls image to closer speaker and prevents even panning, leaving "gaps" or really fast movement.

It does happen. Here is a cite of someone else (well known) who has observed the same problem.

http://audiosignal.co.uk/Resources/What_is_wrong_with_quadraphonics_A4.pdf

You almost need a couch pulled away from a wall a fair distance and the speakers behind you, but most significant others don't like that AT ALL. They want the damn couch/chairs back against the wall. You almost need to build a music or movie room. I found it a bit easier to do a circle with the 5.1 half of the room and let the rest do its thing for movies and Atmos. 5.1 with the surrounds behind me images surprisingly well. I just don't get "far away" discrete sounds appearing. It seems limited to a few feet behind me without them.

I built a music/media room. It is rectangualar with the speakers on the walls.

I can move my chairs forward for 4-corners quad or backwards for movie surround (and the backwards position removes the cogging by putting the front speakers at about 30 degrees from front center and the surrounds at about 75 degrees from back center).

I'm betting if you heard my system you wouldn't hear any cogging.

I wish I could. But it might be that you don't hear it, but I do.

I just listened for like 6 hours to Atmos and Auro-3D music in a 5.1 + 4 overhead + front wide configuration using half the room. It was a bit like being at Disneyland or hearing a binaural sound effect album. I've been working on lighting effects to go with it so it feels like Disney (have numerous movie props that can light up and the ceiling can light up with stars and moving clouds to look a bit like you're outdoors).

I have done similar things. I once built a white cyclorama for someone to put behind the TV. It has a hidden striplight above it and a hidden striplight below it, each with red, green, and blue lamps on dimmers. I was able to create many different sky and sunset effects with it.

 

[MagnumX]

It does happen. Here is a cite of someone else (well known) who has observed the same problem.

http://audiosignal.co.uk/Resources/What_is_wrong_with_quadraphonics_A4.pdf

I didn't mean in general. I mean I don't hear it with my setup.

I have done similar things. I once built a white cyclorama for someone to put behind the TV. It has a hidden striplight above it and a hidden striplight below it, each with red, green, and blue lamps on dimmers. I was able to create many different sky and sunset effects with it.

I looked at those Phillips Hue lights, but they're awfully pricey and I just turn the lights out for projection normally. The starfield/cloud projector is pretty neat, even if the clouds are blue and the stars are green (laser). I thought something that changed with the beat might be interesting, but after experimenting upstairs, it might be annoying too (I've got a plasma projector for the ceiling there that looks like fire or water or some alien atmosphere on the ceiling along with programmable Christmas lights around the edge of the floor.

 

[par4ken]

While I don't want to perpetuate this discussion of side imaging but it made me think back to the days of Quad Quarterly/MCS Review. Bill Somerwick wrote numerous articles preaching about the benefits of Ambisonics. He used to go on about how Pairwise Mixing didn't work. While I still disagree with that blanket statement I was a bit intrigued by the idea of Ambisonics. I would of tried it if there was any program material available that I had any interest in.

Normally I purchase software before getting the hardware to play it on. I started buying quad records before getting a decoder or demodulator. I bought Quad reels before getting the machine to play them on. I started buying CDs before getting a player. So if I would of found one or two records first I might of invested in the decoder.

Over the years I've only ever seen one or two hardware decoders ever offered for sale on eBay.

The theory of how they work is related to adding signal components to other speakers in the right phase relationship to trick the ear into hearing sounds from a particular intended location.. Adding digital delays in the right place improve imaging to me sounds like a similar related idea. Maybe surround mixes could/should incorporate elements of Ambisonics to improve imaging?

Sorry for getting so far off the original topic of the Surround Master!

 

[MidiMagic]

I looked at those Phillips Hue lights, but they're awfully pricey and I just turn the lights out for projection normally. The starfield/cloud projector is pretty neat, even if the clouds are blue and the stars are green (laser). I thought something that changed with the beat might be interesting, but after experimenting upstairs, it might be annoying too (I've got a plasma projector for the ceiling there that looks like fire or water or some alien atmosphere on the ceiling along with programmable Christmas lights around the edge of the floor.

I did that in 1976.

 

[Owen Smith]

While I don't want to perpetuate this discussion of side imaging but it made me think back to the days of Quad Quarterly/MCS Review. Bill Somerwick wrote numerous articles preaching about the benefits of Ambisonics. He used to go on about how Pairwise Mixing didn't work. While I still disagree with that blanket statement I was a bit intrigued by the idea of Ambisonics. I would of tried it if there was any program material available that I had any interest in.

Normally I purchase software before getting the hardware to play it on. I started buying quad records before getting a decoder or demodulator. I bought Quad reels before getting the machine to play them on. I started buying CDs before getting a player. So if I would of found one or two records first I might of invested in the decoder.

Over the years I've only ever seen one or two hardware decoders ever offered for sale on eBay.

The theory of how they work is related to adding signal components to other speakers in the right phase relationship to trick the ear into hearing sounds from a particular intended location.. Adding digital delays in the right place improve imaging to me sounds like a similar related idea. Maybe surround mixes could/should incorporate elements of Ambisonics to improve imaging?

Sorry for getting so far off the original topic of the Surround Master!

The music available in UHJ (the main Ambisonic format) is restricted I agree. And hardware decoders are very rare. Oxford Dickie did some decodes of UHJ and they were fantastic. Once I worked out I had to slide down in my chair to get my ears at tweeter level suddenly the speakers and the walls of the room all disappeared. I have never had that happen with any other format.

 

[MagnumX]

The music available in UHJ (the main Ambisonic format) is restricted I agree. And hardware decoders are very rare. Oxford Dickie did some decodes of UHJ and they were fantastic. Once I worked out I had to slide down in my chair to get my ears at tweeter level suddenly the speakers and the walls of the room all disappeared. I have never had that happen with any other format.

Have you tried Auro-3D or Dolby Atmos? I listened to Diabolo (28 classical reference recordings) last night. It came with many formats and two discs.

Hybrid SACD with 2.0 CD layer, hires 2.0, 5.1 and 2+2+2 (uses center and LFE as front height speakers instead).

A Blu-ray with 2.0, 5.1, 2+2+2 (stored in a DTS-HD MA 7.1 container that my AVR sees as DTS:X but plays correctly as 6.0 and Auro 8.0 (added surround heights).

In 2+2+2 or Auro 8.0, the speakers and walls just disappear as do all Auro-3D music albums I have and some if the Atmos ones (sometimes sounds are purposely located right at speakers by some Atmos mixing engineers which gives them away). I'm sure DTS:X could do the same, but other than demo discs, I've never seen a music album in DTS:X.

 

[Owen Smith]

My amp and Oppo 95 cannot decode Auro 3D, Atmos or DTS-X. I'm still using an AV amp with no HDMI audio, using the Oppo 95 for all decoding and using the amp's 5.0 analogue inputs. My amp is an Arcam AVR350, I can't fit anything any larger physically in my rack (which cuts a lot of modern amps out), I want multi channel analogue inputs (which cuts more out), and I need stereo line level outputs to feed into the transmitter box for my Xeo 3 wireless speakers in other rooms. Between those three requirements there are very few products on the market, and I can't face the effort of tracking them down to be honest.

Ironically the stereo line level outputs are becoming the hardest thing to find, since manufacturers seem to regard those as only for recording and no-one records these days.

 

[MagnumX]

My amp and Oppo 95 cannot decode Auro 3D, Atmos or DTS-X. I'm still using an AV amp with no HDMI audio, using the Oppo 95 for all decoding and using the amp's 5.0 analogue inputs. My amp is an Arcam AVR350, I can't fit anything any larger physically in my rack (which cuts a lot of modern amps out), I want multi channel analogue inputs (which cuts more out), and I need stereo line level outputs to feed into the transmitter box for my Xeo 3 wireless speakers in other rooms. Between those three requirements there are very few products on the market, and I can't face the effort of tracking them down to be honest.

Ironically the stereo line level outputs are becoming the hardest thing to find, since manufacturers seem to regard those as only for recording and no-one records these days.

So ditch the AV amp and get a Marantz 7014 while it's on sale this time of year for $1200. It has 9 channels of amplification plus 11 channel processing (with an external amp you can have 11.2 total). It has 7.1 analogue inputs. It has line level (pre-out) outputs for everything and they operate simultaneously with the internal amps. It has all those decoders and an optional room correction system as well. I use the earlier 7012 model. It's awesome.

That wasn't so hard to find.

 

[Owen Smith]

No such thing as a 7014 on marantz.com. And if the 7015 is the new version it is too tall to fit on my rack. When I said I can't accomodate any larger than the Arcam AVR350 I really meant it, that is the absolute max.

 

[MagnumX]

No such thing as a 7014 on marantz.com. And if the 7015 is the new version it is too tall to fit on my rack. When I said I can't accomodate any larger than the Arcam AVR350 I really meant it, that is the absolute max.

I guess they skipped a number on that series. You could get something like Marantz NR1711 slim form, but it's only 7.2 channel which isn't great for Atmos (5.2.2 max) and no analog 7.1 inputs, but it does do DSD processing (i.e. SACD through HDMI).

I guess one has to go with what's most important to them, though.

 

[chucky3042]

This thread is off the rails!