DIY "Single speaker surround sound"

[Ridin '24'z]

Once again I've been crawling around the internet and have come come across these single speaker sound sound systems. You know, the ones that look like big long boxes that can fit perfect under a flatscreen tv.

I listened to a Yamaha soundbar a number of years ago and it wasn't bad. Very good at projecting the sound, but not the best quality sound.

This kind of technology doesn't seem at all aimed at real audio enthusiasts, but rather to those who are looking for something that works and has very high WAF. Just look at the video and you see...

Surround Sound Speakers from SurroundBar® - Polk Audio

I was wondering if there's any gold behind this technology. Of course you'd want to keep your beloved front channels for the real music, but this would be a good way to get centre and surround channels for the occasional movie or games without the fuss of surround speakers. (I'm personally not interested in surround sound enough to require a full blown setup - mostly listen to stereo music)

I'm sure this is DIYable by having sets of speakers within the unit pointed out into the room and all the drivers and video delayed respectively to the latest reflected sound.

tbh I'm looking for something that's small to have as a speaker that can immerse you in sound and is easy to listen to but not be striving for perfect sound. Like I said, they are no way intended to replace the front stereo channels :P.

[MisterTwister]

Interesting that they are offering passive version of the bars.
I was under impression that they use some kind of processor with sophisticated sound delay algorithms.
With polypropelene woofers, there are probably no crossovers, only caps on tweeters.
And front bezel can provide acoustic filter for woofers. Very smart product, bet it sells better than any other type of speakers.

[Radugazon]

hello,

On the Polk Audio site you have a white paper about this.

Of course they don't say all. Note that the lateral speakers have to be connected between the two (+) of each channel.

here a plan

normally it works if you respect the (delta)T and the wiring, but the sweet spot is very small.

[speaker dave]

Between the Polk and the Yamaha you are talking about two very different approaches.

Polk uses its SDA approach. Out of phase difference signal is fed to the speakers to create null zones that expand seperation. They used it in Stereo days for wider stage stereo. Here they are using it to simulate surround channels with wider spacing than the speakers have. You have to sit in the right spot for the full effect.

Yamaha, and an earlier Pioneer product (see 1 Limited), are using a sophisticated steered array to send thin beams of sound to bounce off of side and back walls and return as surround channels from the rear. A lot of DSP and individual driver elements let them create multiple highly directional pencils of sound.

Probably not a DIY project, yet!

David S.

[Dave Jones]

In 1984, Polk marketed loudspeakers that worked on the principle that sound from the right speaker reaching your left ear (and vice versa) is an evil to be terminated with extreme prejudice. It's an idea that will not die, as evidenced by some threads here on diyaudio. I forget what they are calling it now. Ambiophonics? Yes, I think that's it. It sort of works, sometimes, if you sit precisely in the right spot, and if the recording was made with two closely spaced microphones. It helps if you have your head in a neck brace. How long has it been since any recordings were made that way? What if the recording engineers actually knew what they were doing? What if the sound coming out of each speaker has exactly the effect on a typically placed pair of ears that they want it to?

I heard a pair of the old Polks in '84, and they were nothing special.

This new system seems to be a new twist on the old idea. If I've found the correct patent, it uses four channel input from videos to drive four or six speakers all at the front of the listening area. I am dubious.

Check this out: Enhanced multi-channel audio surround sound from front located loudspeakers

[Ridin '24'z]

Yeah the whole idea seems more hassle then its worth. There might be some good in the Yamaha systems though, I might chuck a few small drivers together pointed around the room and see what I can process them with. I'm gonna get a mini-dsp soon, but until then I have 7.1 connections on my pc that you can do fun stuff with by using ffd audio =]. I'm sure one could build a simple processor in matlab too.

[speaker dave]

Thanks for the references.

When I was at JBL, the first article about SDA came out. It showed how to set up your own version with a pair of narrow bookshelf speakers on each side and the proper connections. We tried it out and had great fun with the phenomenon.

"Money" on Dark Side of the Moon was the best demo as the jangling change was panned hard left and hard right. With your head in the right spot that would localize way outside the speakers.

Carver and Lexicon came out with electronic versions of the same. Its all great fun but the requirement to sit in a narrow zone will always limit its application.

David S.

[norman bates]

sonic holigraphy, good stuff, cheap opamps though.

Check out Q-Sound cd recordings, or even ambiophonics.

Norman

[Ridin '24'z]

Just gave the SDA idea a go. Pretty nifty idea, worked pretty well. Their idea of filtering the rear channel content is quite clever. I'm tempted to make a proper project out of it. What would happen if this where to be put together as an open baffle system??

[Ridin '24'z]

Sonic holography seems like a very interesting way of doing it too. Still trying to understand how it works :P.