SRS Circle Surround

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Obbop

600 Club - QQ All-Star
Since 2002/2003
Joined
Mar 4, 2002
Messages
616
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After listening to Circle Surround at the audio store.... typcially the set-up to ascertain the quality of surround output was lame.... excess ambient noise, poor speaker placement, etc. I did enjoy the "sound" of the SRS Circle Surround output of synthesized surround from a stereo source.

Since it will likely be 3 years or more before I can think about buying a new receiver with all the goodies... Pro Logic 2 or whatever is out in the future, Matrix 6, etc etc etc and since my main desire with quad hardware is synthezing surround from stereo sources, I kept an eye on eBay waiting for a free-standing Circle Surround decoder to appear.

There IS a new format from SRS... a Circle Surround 2 or whatever they call it, but, I don't think it's being placed in receivers or decoders yet and it will likely be pricey so.... when I found a low-priced eBay offering I jumped on it and..... won!!!! Wheeeee!!!!!!

I have never been burned on eBay so am assuming that in a week or two a new-in-the-box Circle Surround device will be plugged into the system. Will submit a review of the output, etc at a later date.

Anyone with experience with Circle Surround is invited to submit their aural experience with the output of this unit.
 
precisely *what* you got on ebay?
My experience with CS is with the sherwood car decoder, which does DTS and CS for analog stuff.
CS with some disc can be quite good, but you need to pump up the rear channels of 4-5 dB.
A disc that shocked me in CS mode was "Reptile" by Eric Clapton; apart from the first and last track, the sound was nearly discrete on all the others. Suprisingly enough, when i tried the same disc with DPL2 i wasn't unable to get the same effect of separation. On the contrary, Madonna's "Music" sounds good on DPL2 and crap on CS.
As usual, some works best with CS, some with DPL2. Just try it.
 
I grabbed a home unit designed to be plugged into a receiver or amp. Hughes designed the original system for use on airplanes and the strange headphones you can rent for listening to music. Hughes sold the technology and SRS ended up with it. I suppose it can't be all bad since Marantz and some other firms are paying to incorporate the circuitry into their units. Some televisions also come with it!!!!

I'm pleased to read that it worked for you on at least one source. Akin to matrix decoders synthesizing surround from a stereo source the effects are likely random and dependent upon how the source material was recorded/mixed/etc.

I eagerly anticipate getting my grubby paws on the unit and putting it through the paces.

Sadly, my Sansui 9001 isn't working in the surround mode... only the Hall made is working. I can't afford to replace it or repair it. Hopefully this will be a low-cost way to obtain more surround sound. The Hall mode is okay but it's not as aurally satisfying as the regular surround mode.

Since that old equipment often needs major work to refresh it I may shun the old quad stuff in the future. I listened to Matrix 6 mode on a high-cost receiver and was impressed with its ability to synthesize a stero source. Marantz has some nifty high-cost receivers that have several surround functions. In the future when the legal tender is overflowing my wallet I may retire the 9001 and grab a new Marantz. Sigh...... if only I was a tech-type and could repair my might 9001 myself!!!!
 
A minor correction on the history. SRS Labs bought the Sound Retrieval System from Hughes. They then purchased the patent and manufacturing rights from Rocktron for the Circle Surround matrix. Rocktron is now out of business but the inventor of CS started another company and has a patent pending on a new, advanced matrix system. Details are at www.isptechnologies.com

Cheers

Norm


 
I have been using a Kenwood VR-410 receiver that incorporates a Circle Surround decoder in it. The reason I bought the receiver was that it included the Circle Surround decoder.

One of the first things I discovered was that the receiver had two Circle Surround modes, music and cinema. The receiver defaulted to the cinema mode which produced very audible pumping when playing back The King's Singers: Good Vibrations, the first CD I tried. This was very discouraging and all but turned me off the Circle Surround.

After reading the manual, I discovered that there was a music mode. Upon switching to music mode the separation was reduced, however I was no longer able to detect the pumping.

I have been using the VR-410 for about a year now and I enjoy the Circle Surround setting very much. The results vary from disc to disc. At its best it can be almost as good as listening to DVD-Audio discs. Matrix encoded records from the quadraphonic era often show the best results.

Some records that I have listened to in the last week that decoded well included:

Angle S-60288 Richard Strauss, Don Juan, Rudolf Kempe w/ Dresden State Orch.

Vanguard VSQ 30020 Handel Royal Fireworks Music / Water Music, Johannes Somary w/ English Chamber Orch.

Columbia MQ33436 Handel Water Music, Pierre Boulez w/ New York Phil.

The Pierre Boulez / New York Phil. is one of the best discs that I have heard using the Circle Surround setting.

I have also found that the results using the Circle Surround are much better than Dolby Surround when playing back CD's that are Dolby Surround encoded!

I believe that the Circle Surround II provides for a center back surround channel that is not provided for on the original Circle Surround decoder. Since I do not have room in my listening room for a center back surround, I have not felt compelled to upgrade.

tcdriver

 
I looked at the ISP site, and their HTD 6.1 sounds good. Can't find any info on availability or price though. Anyone know?

Dan in Spokane
 
To comment on Dan's statement, the CS II indeed has a center surround channel. There is a separate output for that channel. It requires another amplifier and speaker for that information. If you are using the original CS the material will appear as a "phantom" between the left and right surround speakers, if encoded.

I think the ISP decoder sells for about $500. You can contact them via email or look at their list of dealers on the website. I have one and it works extremely well.

The "Cinema" mode on these decoders solidifies the center channel for film playback so that dialog is "nailed" to the center speaker. The "Music" mode presents a phantom of center channel information for systems that do not have a center speaker (like QUAD setups)

The channel separation in CS is better than 27 dB from front channels to the surround channels. That's better than a stereo record that is about 25 dB between the left and right channels. The published specs show about 40 dB maximum but there is a cavaet. If there is information on only one surround channel at any particular moment (and not on the other channels) a small amount of that signal must be "leaked" to the corresponding front channel during encoding or the martix will "wander" This is not necessary if there is material on the other channels.

Jim Fosgate's Prologic II is compatible but not exactly the same. They had to avoid some of the patent claims in the CS design and "work around" these claims.

Cheers

Norm
this reduces the separation a little. thi
 
So, Norm, is the HTD 6.1 the best synthesizer for stereo sources? Maybe we should start a poll. I actually like the Tate II, because it is so discrete, but it does have lots of artifacts on some material. The QSD-2 is nice, but I don't feel it is very discrete in its placement of sources, more smeared. One of the best all around I've had a chance to use was the Harmon CSP-1? Car unit. Not as discreet as the Tate, but not as many artifacts. DPLII is nice, but it didn't wow me like I expected from all the hype. I haven't given CS a proper audition yet. So what do we think? Should we start a new thread on this topic?

Dan in Spokane
 
I posted a link to DPLll and not much responce to it . It is an encoder format that I felt had some interesting possibilities to it . But I"d like to try out the CSll also and any other format to make 5.1 from stereo encluding UNWRAP .. If used right it could do an excelent job... Albeit expensive but ... Hey why not ! I know of alot of music that would sound great in surround...
0] Rob
 
I have been using a QSD-1,sans blend resistors,slightly modified front end,since 1980.This year I have it slated to come out of the rack and get recapped,but I have done some surround comparisons between it,a Tate 101a(B ser#)and PLII in my Denon 2802(music mode).I have to say my old Sansui is still hard to beat on 75% of the music I've tried!!(mostly rock,prog.) I don't know if it's the triple band decoder that makes the difference or what,but to my ears I still have to give my old girl the nod for best sounding surround synthesis of stereo material compared to the above. I don't have a CS II decoder yet to have a full shootout,but I'm looking!!8o :D
 
I haven't heard CS or DTS NEO, but of the more popular synthesized surround schemes I have heard, my preference works out thusly:

1. Sansui Vario-Matrix
2. Dolby Prologic II
3. Fosgate Tate 101a

 
Maybe it's just me, but the variomatrix, while very aggressive, doesn't sound discrete like the Tate. Do you guys agree, or maybe my variomatrix is wonky. The Tate puts the vocals front and center (when in the stereo mix that way) and a nice discrete sound field around. Now, it may not be your favorite because there are lots of pumping artifacts, but that aside am I wrong? The Variomatrix has vocals seemingly all around, not locked in front, to me, and its hard to localize instruments. I don't want to change opinions, just get to the strengths and weaknesses of each.

Dan in Spokane
 
Hey deepsky: I will suggest that if you have your qsd-2 re-capped, calibrated and blend resistors removed (call QuadBob), you will then quickly move qs-variomatrix to the top of your list. I recently had my qsd-1000 quadbobed. One of the many improvements noted: better front channel staging and center front imaging, not to mention front/rear and side/side separation. Try it, you'll be glad you did. Makes me wonder why anyone bothered with the effort of coming up with PLII, CS, CSII, NEO 6, Logic 7, et al., when we already had qs/vm? go figure.
 
I agree that the QS sounds great through my QSD-2 (single band decoder). I have not heard the QSD-1 but would like to find a used unit somewhere. I am very impressed. The SQ part of this product is only half logic but does a fair job.

I borrowed a Fosgate Tate II from my friend Gary Reber in California who is the editor of Widescreen Review magazine. He used to work for Tate many years ago. He sent me his unit to play with which had been modified for studio use with balanced inputs and outputs. I never could get all the pumping out no matter the settings and interactions. I sent the unit back after two weeks. I would rather hear crosstalk than channel pumping.

Yesterday I talked with my old friend Buck Waller who designed and patented the Circle Surround system in the mid 90’s. He sold the rights to SRS Labs. He has a new company called ISP Technologies that has a sweet matrix decoder with patents pending. I bought one of his units a year ago and found it is very compatible to CS and does a credible job on decoding QS, but not exactly. Buck promised to call me back next week when we can chat about the technical differences between the many matrix schemes from a designer standpoint. I look forward to that.

I think the reason these new systems are appearing is to be able to play movie soundtrack material (hard center channel and sub woofer low pass output) and music material. The early quad systems do not do this well.

I have a CS studio encoder (hardware, not software) that I use to move CD-4 and tapes to standard CD. I also have the studio CS decoder but use the consumer version in my playback system because I cannot hear a big difference. When playing back QS material through the CD decoder it sounds brighter. When playing CS material through QS is sounds duller with less separation. In either case there is no pumping between channels when the decoder is in the music playback mode.

I am really pleased to find this QQ forum. I have already learned a lot from you guys!

Cheers,

Norm

 
Well, as far as stereo-to-surround decoders go, my preference really depends on the source material. I have noticed that the Tate is much more source dependent than other decoders. It can make some stereo material sound very outstanding, with little or no artifacts and a very discrete presentation. However, when something doesn't synthesize well on the Tate, it sounds downright terrible. At the worst, I can hear lots of distortion and noise coming from the rears (usually in the form of annoying clicking and popping). This is due to the clipping that occurs between the front and rears. It actually doesn't sound bad until you turn down the fronts and listen only to the rears. Again, this only happens on certain source material that synthesizes quite poorly, probably because there is not much out-of-phase material for the Tate to work with.

However, with the QSD-1, this never occurs. Depending on the source material, the QSD-1 cand sound every bit as discrete (if not more so) than the Tate. Also, it doesn't do that clipping between the front and rears to achieve a more discrete result. As such, even on material that synthesizes poorly, the QSD-1 always offers a smooth presentation. The same can be said for DPLII. While I much prefer the QSD-1, DPLII offers the addition of the center channel (not that big of deal for me) and a subwoofer (now this I like!). However, DPLII is not always as agressive as the Tate or the QSD-1, and for this reason I list DPLII third on my list.

So, it all boils down to the source material. I just play around with the different decoders and use the one I think works best with the disc in hand. However, if I'm lazy and just want to enjoy the music, I'll just use the QSD-1, and while it may nto be "the best" for that paricular bit of music, it never lets me down.

 
Anyone tried an Ambisonic decoder? (Yep, that weird British format that's been around since the late '70's and never took off)
I've just got back from visiting a friend in Sheffield, and I was completely blown away. Not a discrete sound, but that isn't really the point of ambisonics as you kind of forget the fact that speakers are there. Decoding from stereo is staggering -Yes' Keys to Ascension live albums were just plain knock-out. I think it's mostly the height information that helps. Either way, I might just be on the lookout for one of these beasts! :D
 
Check out this product made in Canada. Been around about a year and has excellant reviews. it even does SQ.

I think is sells for about $1200 and is a new design.

Details at www.cantares.on.ca/decoder.htm

Cheers

Norm
 
Dear Scottmoose, I think your impressions are correct! For many years I used a Minim Ambisonic decoder for all of my classical listening. It presented a most natural sound when you wanted a wash of sound, but it didn't present a detailed soundfield. My listening space always seemed bigger with the Minim, but if the recording begged for specificity in space, I always seemed to get the basic matrix signature. The UHJ recordings made for the Ambisonic process remind me of Circle Surround recordings, very reverberant, however CS is quite better at the image game.
Dwight
 
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