Price Paid:  $80.00 from ebay

Summary:
i have used this processor with a kenwood basic set of a C1, T1 and either an M2 or M2a. it has a strenght in that the first pair of speakers had were Altec Lansing Model 100. these are adequate but not up in the same league as the hardware. it gave the speakers the ability to pretend like they belonged. the second set, with better and worse results were maggies...better soundstage depending on what the source was. radio always worked, cd depended on what it was...vinyl and reel-reel was awesome no matter what. again rock has less impact but jazz and classical is the best way to use it. the third set which i am still toying with is a set of Dahlquist dq-10. the speakers on their own do an admirable job of "space". the c9 in their case mostly defines what you hear in the space. all in all it is a toy, which for parties is turned off, but is always on when the lights are off and your listening to vivaldi, bach, rach, miles, najee or whoever else has talent and you fiddle enough with everyting to get the most out of it.

Strengths:
useful, and just like most things, use it if you like it.

Weaknesses:
has no weakness....it only does what it does, if in your situation it doesn't work or you don't like it, unplug it.

Price Paid:  $75.00 from Private Sale

Summary:
I purchased this unit because of the small soundstage in my listening quarters. I was amazed when I pushed the buttons and it worked. The music seemed further away, and just then, a horn was blowing right in my face. WOW! I use this when I listen to very detailed music to widen the room. I wouldn't suggest using it with fast rock, classical, or anything busy. I'm satisfied with my purchase and recommend it to audio enthusiasts like myself. It works, but I don’t think audiophiles would appreciate it. For $75.00 this is a steal! The only reason I gave it a 4 in overall rating is because of the poor representation of "busy" music.

Strengths:
It works!!!! It really works!!!

Weaknesses:
This unit adds line noise, even when ran through my line conditioner. Switches are loud - this could be due to age. Busy music does not image as well as acoustic.

Similar Products Used:
None

Price Paid:  $100.00 from ebay

Summary:
Well this is my second time around on this unit. I first purchased one of these back in 1982 at the time I was 19 and I bought and sold gear like mad. Then in 86 I purchased A complete Carver system and with this the pre-amp had this feature built into it so I sold it not even thinking down the road. Well after all these years I finally but new gear and have missed the Sonic Holography part of the system. One day I was ebay looking around and wondering if I could find just the processor part to put into the signal path and lowe and behold there it was. I made contact with the person since it was local. Well the true test was going to be how would it sound with Magnepan 1.6's. Since these speakers are somewhat critcal in there positioning and remembering from the past that the setup with Sonic Holography is very important to get the most from it I thought well this should either sound great or terrible. The initial impression was fair but not satisfying. So I had to determine what I thought was wrong. When engaging the unit I notice that the top end on some things tended to sound hot. I initialy thought maybe the unit needed to be service but yet when I stood by one speaker and engage and dis-engaged it sounded the same which made me think ok its the positioning of the speaker and how it cancels the signal that is causing the problem. I slightly readjusted the maggies and it then became much better but yet still alittle to hot on the high end. I then used the attenuators that Magnepan sends along for the Qausi Ribbons. These attenuators are to help control the Quasi becasue they are so efficient. Once I placed them inline all of a sudden it was like night and day. The speakers completly smoothed out and the soundstage just open way past the speakers reaching to the far left and right. At one moment I thought I had the surround side of the processor turned on it very convincing. Sonic Holography does add a whole new dimension to music especailly Jazz and Classical. I am glad to see that this feature is still available thru Bob Carver Sunfire company. It helps bring a bad sounding CD back to life.

Strengths:
Its ability to restore music in a more correct time domain versus someones poor studio mix down.

Weaknesses:
None Other than Sunfire doesn't offer this yet as a separte add on.

Price Paid:  $350.00 from Jerry's

Summary:
I bought this when it was hot on the market, and I'll never give it up. It really does provide a stage where you can point to instruments and voices far and near, and between and outside the speaker placement. Have to turn it off watching movies though; the cancellation signal for L-R or R-L makes the center channel hard to hear; although there was a model made that supports center channels (movie mode). Value rating is for what you can get it for now, but at the time I bought it, it was still worth every penny.

Strengths:
Nothing like it.

Weaknesses:
Messes up center channel on movies.

Summary:
First of all it really does work. I bought this new around 1985 and have no intention of parting with it. Intuitively, the affect doesn't seem possible. First off it enhances the imaging in the area between the speakers, but it also can spead the imaging to the outside of the speakers - sometimes far outside. Note this is NOT the same as just inducing a broad diffusion of the sound field like Bose 901- at it's best it is very precise imaging of individual instruments and performers. Personally, I find the effect better sounding and more effective than any surround processing derived from an unencoded 2-channel source.

Speaker positioning: Although it is true that there are specific requirements for the speaker set up, I have found that less than perfect placements can work pretty well although you don't the the maximum effect. I have also found that they are not that much different from the requirements for good imaging. To the extent they differ thehr are no more difficult to achieve than the more normal placement. The most important thing is to minimize side and rear reflections. In lieu of exact placement, absorbant treatment behind the speakers will work. My best results have come from using a pair of otherwise unremarkable satellites. On the otherhand I'm now using it successfuly with a pair a Magnepan - I had not expected this combination to work due to the Maggie's dipolar nature! The position required from the listener is important, while you can't walk around the room and expect the effect to still be there you do have a little bit of lattitute and the unit does provide a setting that gives a little more leeway.

Source material: The most dramatic effects seem to come pop music mixed down from several tracks. The result is probably nothing like the engineer had in mind, but I have always found it at least as enjoyable as the unprocessed stereo. With symphonic music the initial results usually seem less dramatic- you don't, for instance, hear each violin in it's own space, but with a bit of time listening you ralize that what the C-9 lets you hear is the reflections from the walls. It is not as encompassing as DD5.1 or DTS recorded symphony but it is much more pleasing (to me) than the typical "Hall" option you get with from DSP processor.

With some sources the C-9 does absolutly nothing. My limited technical understanding is that the process relies in phase differences between channels and on the degree of sereo separation between the channels. There must be some but not too much. This is probably why pop music with complex mixing gives the most dramatic but somewhat unpredictable results.

In summary, I have never hear the C-9 do anything bad to the music. The worst case is that it doesn't do anything. C-9's appear from time to time on Ebay; usually dirt cheap $40-$60. You do need a way to patch it in to the analog line level (NOT DIGITAL!) signal path. Tape monitor loop or pre-outs on a reciever or between preamp and power amp. (Between the analog out of a CD or DVD player and a reciever should work, too.) By the way, the C-9 cicuitry is currently bult into the the Sunfire HT tuner-preamp if you are in the market for something of that caliber.

Strengths:
Creates a sound stage from 2-channel stereo that no other device I know of can duplicate. Worst case scenario is that it does no harm.

Weaknesses:
No longer in production. Requires somewhat specific speaker positioning.

Similar Products Used:
Nothing like it.