A few thoughts on the C-9 Sonic Hologram Generator…

I’ve been listening to music with SH for years, originally with a CT-3 preamp and more recently with a Sunfire TGP-5. I got the C-9 through one of Rich’s Karmas a few months ago, primarily because I wanted to compare its effects to the TGP-5. Thanks again, Rich

My system is on this page. http://www.thecarversite.com/yetanotherforum/default.aspx?g=posts&t=501 The ribbons are 9 feet-6 inches apart, and are each 12 feet-3 inches from the listening position. That’s an angle of about 45 degrees between the speakers. The speakers are toed-in somewhat, pointing about 2 feet outside the listening position. I ran the analog outs of the CD player through the C-9 and on to a pair of spare inputs on the TGP-5. I kept a direct digital connection from the CD player to the TGP-5 for comparison.

The C-9 has three switches, Injection Ratio, Listening Aperture, and SH In/Out, which allows you to disengage the SH effect. (The Sunfire has no switches for Injection Ratio or Listening Aperture.)

The Listening Aperture switch can be set to NARROW or WIDE. The NARROW setting requires that the listener remain inside a small window to retain the best SH effect. Setting the switch to WIDE provides a wider listening window which allows more movement, presumably at a cost. The Injection Ratio switch controls the strength of the SH effect. The NORMAL setting has a weaker effect and is recommended for multitrack recordings mixed down to stereo. The THEORETICAL setting is recommended for recordings made using stereo microphone techniques.

I started with the noise bursts on Track 12 of the Carver CD-4000 Test Disc. This is a great track for isolating where the sound seems to be coming from. I started fiddling around with the switches first.

Switching back and forth between NARROW and WIDE, I couldn’t tell any difference in the effect. None at all. The noise bursts seemed to come from the same spots in either setting. And regardless of the setting, the effect was totally gone if I moved my head a foot in either direction, left or right. From this point on I left it in the NARROW setting.

Then I started switching between NORMAL and THEORETICAL. Big difference there. In the NORMAL position, the noise bursts had spread to about 90 degrees apart. Switching to THEORETICAL added about 15 to 20 degrees on each side. The noise bursts also seemed to be coming from a greater distance in the NORMAL position.

I left the switch on THEORETICAL and started listening from different spots to see how the effect changed. Moving forward, closer to the speakers, it seemed to diminish. Moving back, away from the speakers, it continued to open up. It didn’t seem that the spread angle was changing all that much, just that the sound was moving further and further away from the speakers. I was pretty amazed at this point. In my experience with SH, I had never heard anything sound like it was coming from such a distinct location so far away from the speakers. I ended up moving the listening chair back about 2 feet from its original position and leaving it there.

Comparison with the TGP-5:

I checked the noise level first. At full volume and no input, the noise level from the digital connection to the CD player was noticeably higher than the analog input from the C-9. I have no idea why. Either way, I don’t think the noise would be audible at normal listening levels.

Going back to the noise bursts, I compared the spread created by the TGP-5’s SH function to the C-9. The TGP-5 was about the same as the C-9 in the NORMAL setting. In the THEORETICAL setting, the C-9 was much wider. I’d have to guess the algorithm for the TGP-5 was based on the NORMAL setting in the C-9. It’s a shame the Sunfire doesn’t have the ability to switch the Injection Ratio setting.

I did some comparisons with the music on Track 13 of the test disc. The CD manual says the sax should appear to come from about 45 degrees to the left of the left speaker. Through just the Sunfire, the sax came from only slightly to the left of the speaker. Through the C-9 (in THEORETICAL), the sound was noticeably further to the left. Not quite 45 degrees, but still impressive. Interestingly, both the TGP-5 and the C-9 were much better than the Holography Encoded Music on Track 14 with SH turned off.

Next step: Comparison with some of my favorite SH music.

Nice intro to SH comparison, Harryfan. Are you going to fiddle with the speaker toe-in at all?

When you compared noise levels with no input, are you sure that you had the SH button engaged on the C-9? If you left it off by accident, that may have caused the lower noise floor. This may not affect the position of instruments, but will affect the quality of the sound.

I assume the TG5 is basically the same as the pre section of my Ultimate receiver 11. When you used the C-9, did you use STEREO or DIRECT SOURCE setting on the Sunfire? If you normally have that particular input set to STEREO, it will digitize the signal, as opposed to DIRECT SOURCE which will leave it analog.

I look forward to your music reviews. =d>

Nice review Harryfan.....

I only have the SH on my TGP-5, although I am trying right now to win one on e-prey.

I dont really have a proper room besides my HT, but this is what I have found

with different types of speakers in the same room..

1) My new open baffles...... This did absolutely nothing except garble, almost like one speaker out of phase
These are the best speaks I own, and some of the best I've heard

2) My Original Amazings.....Really opened up the amazings, Made the sound stage much wider and improved
the imaging and defined placement of vocalists and instruments.

3) My line arrays...............OMG!!, What the SH does to these is just short of amazing. On live tracks that are
clean you can close your eyes and when the audience applauds you can close your
eyes and you would swear you were among them...They are literally on each side of
you. On most of my good cds the instruments and vocalists are pinpoint and the imaging
is absolutely the best I've heard, they make it sound as if you were 6' away from the
stage and add the most depth you could imagine.

I'm the worst guy to give audio explanations, but the point I'm trying to make is that with 3 very good high end sets of
speakers, the effect is different for each.......the weird thing is the SH sounds the best on the one set that is not dipole (or bi?)
which is exactly opposite from what I expected. When I get my 2ch room set up this summer I will be able to compare
them again, hopefully with my new SH from e-bay.........o:)

Perry

Bill, that is true if you are using the SH in the Sunfire. But the C-9 is connected to an aux input and therefore can be passed straight thru in analog if the sunfire is set to SOURCE DIRECT. (ie the SH processing has already been done therefore it is now just an analog signal being inputed)

I know this is 9 months later but thanks for the great info on the C-9. I have had mine since 1982 and it still works great with my Denon system. Again GREAT SITE.