SDA Control Switch ??

altecman

I know this might be a dumb question but has anyone tried to adjust the SDA signal e.g. by putting a rheostat in the interconnect cable to vary the SDA signal. The reason I am asking this is because the SDA principle is so dependant on miking positioning and alot of recordings which aren't so precisely miked cause an imbalance in the SDA effect. The result of poor miking makes the sound stage too wide and unnatural e.g pianos solos can sound that they are 20 foot wide.. Whilst I have become a great admirer of the SDA I find that I can't listen to alot of recordings due to the unnatural sound affect. Life would be simple if miking techniques were set correctly in the first place but life isn't that simple.
I was just wondering if anyone has thought of this before and tried to rectify, the only other option would be to put the speakers closer together but this will only work on music which has been poorly miked.

BIZILL

you know you'd want it to be remote-controlled as well. anyway, i sorta see what you're sayin'. but at the same time, i don't really experience it. i know that some songs sound better/worse than others. but nothing as bad as you make it seem. so to what you ask i say, if it ain't broke, don't fix it. for me, anyway.

danger boy

whenever i run into music that does not sound good with the SDA's. I just unplug the SDA cable.. problem solved. it lessens the SDA effect..and sounds good to me. give it a try.

Even unplugged the SDA sound field is still present. trust me. i know what i'm talking about. It's just not as forward.

ben62670

altecman wrote: »

I know this might be a dumb question but has anyone tried to adjust the SDA signal e.g. by putting a rheostat in the interconnect cable to vary the SDA signal. The reason I am asking this is because the SDA principle is so dependant on miking positioning and alot of recordings which aren't so precisely miked cause an imbalance in the SDA effect. The result of poor miking makes the sound stage too wide and unnatural e.g pianos solos can sound that they are 20 foot wide.. Whilst I have become a great admirer of the SDA I find that I can't listen to alot of recordings due to the unnatural sound affect. Life would be simple if miking techniques were set correctly in the first place but life isn't that simple.
I was just wondering if anyone has thought of this before and tried to rectify, the only other option would be to put the speakers closer together but this will only work on music which has been poorly miked.

A 100w speaker volume control would allow you to make it variable.
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=300-560
You could use this one. Its cheap, but like nearly all controls of this type it is impedance matching. No problem it is stereo, just tie the left, and right wire together. I do it, but I use separate amps for the stereo, and dimensional arrays. Its a nice feature:)
Ben

F1nut

Maybe it's just me, but I never understood that piano comment on SDA's. It seems to me that when listening to a piano solo at a live venue, it does project a very wide sound stage.

ben62670

F1nut wrote: »

Maybe it's just me, but I never understood that piano comment on SDA's. It seems to me that when listening to a piano solo at a live venue, it does project a very wide sound stage.

It does:)

altecman

The piano solo statement I suppose was a little exaggerated but to me its just seems that some things seem too far apart. Another example would be vocals, when the person singing seems to drift left or right or that the instruments are playing way outside what you would expect. It could be me asking too much but the SDA effect can be a little disconcerning.

altecman

ben62670 wrote: »

A 100w speaker volume control would allow you to make it variable.
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=300-560
You could use this one. Its cheap, but like nearly all controls of this type it is impedance matching. No problem it is stereo, just tie the left, and right wire together. I do it, but I use separate amps for the stereo, and dimensional arrays. Its a nice feature:)
Ben

Ben,
As I have the old blade/blade style is it a matter of just cutting into one wire or do I have to cut into both. I think I've answered my own question as the two wires both carry inverting signals. Correct me if I'm wrong.

F1nut

What is your set up like? How far apart, how far from the side walls, how far from the back wall, and how far away do you sit? What gear you using with your SDA's?

They should be no toe in with SDA's.

altecman

Speakers are about 12' apart and 3' away from the side walls and I'm sitting about 15' back, 8'6" ceiling. The chair I sit in is about 1' from the back wall. The amp I'm using is a high current 120Wpc Aussie built ME 750 power amp and matching Preamp, capable of driving loads down to 1 ohm. I tried putting the speakers apart as the usual equilateral recommendation but was finding that the soundstage was far too wide.

ben62670

altecman wrote: »

Ben,
As I have the old blade/blade style is it a matter of just cutting into one wire or do I have to cut into both. I think I've answered my own question as the two wires both carry inverting signals. Correct me if I'm wrong.

Give me a few to ponder my recommendation. It may not work with B/B.
Ben

F1nut

Ok, I run mine 6 feet apart, about 6 feet from the side walls, 6 inches off the back wall and I sit about 9-10 feet back with 3+ feet behind my head. Ceiling is 8 foot. Driving them with about 650 wpc @ 6 ohms.

I'd like to suggest you try them closer together, 6 to 8 feet is recommended, sitting 9 to 12 feet back, therefore bringing your chair further off the back wall.

I can't say for sure as I've never heard your amp, but I have found that they can/will make a huge difference as to how the SDA performs and I'm not talking about the high current/wpc thing.



Due to the stupid edit rules around here, my previous post should be edited to read, "There should be no toe in with SDA's."

ben62670

F1nut wrote: »

Due to the stupid edit rules around here, my previous post should be edited to read, "There should be no toe in with SDA's."

Well I think one of us should hold ~J~ down, while the other slaps. You want to slap, or hold?

Ben

BTW I hope the Cig withdrawal is going well:)
Ben

altecman

F1nut,
I could have some fun here!!! Remember that post about a person going off about the advise from a Polk rep saying about the recommended positioning and everyone else were stating what was in the owner's manuals. Gee that thread such a joy to read.
The ME750 amp is probably the best SS amp I had for a long while and I've had about 80 or so different amps (valve & SS) in the last 27 years, I don't think it's the amp, I think I'll have to experiment with the positioning as you did..
PS. I hope you aren't driving them at about 650 wps @ 6 ohms all the time - what's that I can't hear you??? you will have to speak up!!!

F1nut

Hmmm....I don't recall that thread......too many, ya know!?!

Right, all I was suggesting was to try a different arrangement. 80 amps, helluva lot of amps....lol.

No, I listen at 90-95 dB most of the time...just a few watts, but balls when needed.

F1nut

Ben, probably a friendly chat would be best.

I don't know where it's going, to be honest. Grrrrrrrrrrrr *#@*&#%!*

ben62670

I say slap, and sterilize, but I feel that may be a bit strong:eek:
I was called a bully

altecman

Guys, what's all this about, I hope not at my expense.

ben62670

altecman wrote: »

Guys, what's all this about, I hope not at my expense.

Nope a main moderator;)

F1nut

Nothing to do with you Altecman. Just a friendly ribbing on my behalf to our Chief Webmaster, that's all. I can't and won't speak for anyone else.

Let's get back on topic.

altecman

F1nut,
The topic about positioning was when this chap said he was told by a Polk rep that SDA should be placed 1' from the side walls and that he knew more than anyone else on this forum site.

F1nut

Ah yes, I recall that now. Funny stuff.

F1nut

Looking a little deeper at your position about the SDA's sound stage. It's not for everyone and it's not perfect, but what is? For me, the standard stereo that most are use to falls very short.

If placement doesn't make things better for you, try your idea. The results would certainly be of interest.

altecman

F1nut, Thanks for the advice, will try putting speakers closer, let you know the outcome.