Challenge: Polk SDA -vs_ Carver Sonic Holography

audioluvr

Well I got bored today and decided to pull some of my old Carver stuff out of the closet. I've heard good things about their C-1 pre and thought I'd do an A/B comparison between the SDA effect and the SH effect. Not sure how ideal this comparison was but this is how I did it.
Carver C-1 pre
B&K M200 monoblocks
Cambridge audio DVD99
SDA Effect: Polk SDA 1C w/800va Dreadnought
SH Effect: Polk SDA 1C no interconnect

Output without the SDA's interconnect made the output a little less dramatic so I would turn the volume up to similar levels.
Since I only have one set of good RCA IC's I used them between the pre and the amps. I would listen, eyes closed, to a track and try to point out particular moments where I could pinpoint a sound that was clearly outside the speakers then unhook my IC cable and turn on the Sonic Holography.

Sonic Holography employs, as far as I know, all drivers and tweeters for the effect. Imaging even though it was wide was not quite as wide as SDA and seemed more diluted. I think this was possibly due to it's use of the tweeter array and possibly due to the fact that the C-1's circuitry is over 30 years old.

One thing I have to note here is when using the C-1 in SDA mode this way it had excellent imaging for it's age. I imagine with a factory refresh it would be far better. Also it was dead quiet. turning the volume up as far as it would go and sticking my ear right up to the speakers displayed dead silence.

R.

nooshinjohn

Run them both together if you really want to have your eyes opened. All I can say is WOW!

FestYboy

It's like you're there....

This experiment brings up a question I've been meaning to ask: as I understand it, when the IC is not employed, the SDA drivers become inactive. As such, the MWs then become additional PRs? If that's the case, wouldn't it stand to reason that the output would be dramatically different (read: bad)? Also, is there any way to "lock" the SDA drivers when the IC is disconnected?

audioluvr

nooshinjohn wrote: »

Run them both together if you really want to have your eyes opened. All I can say is WOW!

Ok are you just f**king with me? I would think they would cancel each other out or muddy the crap out of everything...

VR3

when you disconnect the sda cable, the sda drivers are doing pretty much nothing

audioluvr

understood. They kinda turn into little PR's

mlistens03

FestYboy wrote: »

Also, is there any way to "lock" the SDA drivers when the IC is disconnected?

Gently tap the driver magnets with a hammer. tada! locked driver.

Sounds like a good test! I've wondered for a while how the sonic holography compares to SDA. Now I know!
I have read that SH is less affected by room placement, whereas placement can make or break SDA. Is this true in your experience?

stretchl

Anyone have a link to explain the term “sonic holography?” I’ve not heard that term before. Thabks.

motorstereo

stretchl wrote: »

Anyone have a link to explain the term “sonic holography?” I’ve not heard that term before. Thabks.

http://www.carveraudio.com/phpBB3/viewtopic.php?t=3471

K_M

FestYboy wrote: »

It's like you're there....

This experiment brings up a question I've been meaning to ask: as I understand it, when the IC is not employed, the SDA drivers become inactive. As such, the MWs then become additional PRs? If that's the case, wouldn't it stand to reason that the output would be dramatically different (read: bad)? Also, is there any way to "lock" the SDA drivers when the IC is disconnected?

I thought most if not all SDA speakers use the dimensional drivers as bass drivers all the time.
Is there not a crossover like at 150 hz that gives bass sounds to those drivers whether or not they are cross connected with cable?

F1nut

All one needs to know is SH does not work as well as SDA.

audioluvr

F1nut wrote: »

All one needs to know is SH does not work as well as SDA.

Bingo! Plus SH is really designed for speakers that have all their components lined up vertically so it's limited. Horn speakers don't work because they're all not on that plane.

RobbyKY

I have several C-1's and have tried this using one that I've completely rebuilt way beyond the typical "BillD" modification. All resistors changed to metal film, all capacitors upgraded, improved diodes, etc, etc, etc. Did this on a set of 3.1's because I figured the lower dimensional drive count would give a better comparison than on the 1.2's. Love my Carver stuff but pure SDA was the clear winner.

Back in college, the local AOR station (WKQQ-FM Lexington, KY) I later worked for used to have "Carver Sonic Holography Hour" every Friday night at 10:00pm. Could actually experience the effect on my old dorm rig. When I graduated, my first real purchase were Polk 2B's and a Carver set-up.

verb

Interesting experiment. I too was SH curious such that I picked up a C-9. Plan is to try it out, eventually put it in the garage rig. I like the flexibility of being able to use any speaker, although generally proclaimed not as good as the SDA technology.

heiney9

SDA is not an effect. It tries to minimize a naturally occurring aural phenomenon using an acoustical method

Carver uses primitive electronic simulation (electronic effect).

Current SDA tech in the sound bars uses a combination of an algorithm and acoustic properties far more advanced than 30 year old Carver electronics.

H9

audioluvr

heiney9 wrote: »

SDA is not an effect. It tries to minimize a naturally occurring aural phenomenon using an acoustical method

Carver uses primitive electronic simulation (electronic effect).

Current SDA tech in the sound bars uses a combination of an algorithm and acoustic properties far more advanced than 30 year old Carver electronics.

H9

Uh... Yes! Exactly! (I think)

RobbyKY

Carver uses primitive electronic simulation (electronic effect).

Current SDA tech in the sound bars uses a combination of an algorithm and acoustic properties far more advanced than 30 year old Carver electronics.

Totally agree with the comment but as I tell my younger wife, sometimes older and simple is all ya need.

I still like vinyl run through a combination of 12AX7/KT88 tubes which predates Carver SH by 30+ years. At least for the 12AX7, the 88 popped up in the mid-fifties if memory serves me correctly tonight. The crossover circuits in all our SDA's goes back to the beginning of electronic technology (albeit much improved components, still just inductor/capacitor/resistor/copper wire) and predates the transistor by years.

BTW, of my modified C-1 & C-4000t preamp collection, I only bothered to upgrade the phono and SH circuits in one of them. Been a long time since I pressed the engage button on any of 'em.

On the other hand, after reading the AQ cable shootout thread under another topic, I ran the digitized bits of Madsen's instrumental version of "Stairway to Heaven" stored on my Synology NAS into a Sabre 32-based DAC and solid state amplification then into the 1.2tl's via MIT Shotguns last night at an obscene volume level and drove both my kids to slam their doors. Technology marches on but I find joy in all of it.

Except microprocessor volume control -- must -- continue -- to--resist,
and the cassette tape revival...let me quote Stephen King from his Pet Sematary, "Sometimes dead is better".....