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View Full Version : What is Bi-Amping an SDA?


riglehart
03-11-2006, 10:49 PM
The SDA brochure says...


For even greater dynamic range and lower distortion, the SRS loudspeakers may be connected for Bi-Amplification using the two sets of inputs provided on each loudspeaker. No electronic crossover is necessary. By permitting different amplifiers to reproduce the high and low frequencies separately, the SRS loudspeakers achieve their greatest sonic potential.


So, how do you get high frequencies to go to one amp and low to go to another when you only have 2 full frequency preouts? Do you need a preamp that supports this, or another piece of equipment that does the seperation?

Reason I am curious is that it seems like dual bridged amps are a headache and you need a special SDA cable to do it.

george daniel
03-11-2006, 11:10 PM
One amp to the lower binding posts on both speakers, another amp to the upper set on both speakers.NOT to be confused with mono's(one amp for each speaker),in the "mono" config, the amps need to have a common ground,otherwise you will need the special cable and trans. for "non common ground" amplifiers. Hope this helps,and, Welcome to Club Polk.

BobMcG
03-11-2006, 11:20 PM
So, how do you get high frequencies to go to one amp and low to go to another when you only have 2 full frequency preouts?

You don't, you would have one amp powering the highs and one amp the lows.

Do you need a preamp that supports this

No.

or another piece of equipment that does the seperation?

Yes. You could use an external crossover to achieve separtation before the speaker.

riglehart
03-12-2006, 11:55 AM
I found this, which helps quite a bit...

http://www.davidmannaudio.com/faq/faq12.html

Seems like something a novice should avoid. Especially with the added comlexity of SDA.

BobMcG
03-12-2006, 12:46 PM
Seems like something a novice should avoid. Especially with the added comlexity of SDA.

Nonsense. Don't let it throw you.;)

As the Polk manual states, you don't need to use an external crossover. The fact that it's SDA doesn't make the job any more difficult either. If you want to try it just do it. If you want to add an external crossover at some point that's ok too.

When I got my 2.3s some tens years ago I first had them vertically biamped (top & bottom) using two different but similar amps, then went to two matching amps and then went to horizontal biamping (left & right) with two matching bridged-to-mono amps, a Polk AI-1 and biwires. (*Remember, these are 2.3's though not SRSs.) They're all good ways to explore what your Polks can do.:)

*In reference to the use of an AI-1