Horizontal, passive biamping SRS-2s?

Dawgfish

Hi all. I have found another Anthem Amp-1 close to me for a reasonable price. I'm thinking of picking this up and biamping my SRS-2s with my current Amp-1. I know if I vertically biamp the SRSs, the amps would essentially be acting as monoblocks and this would cause problems. If I horizontally biamped these though using one amp to drive the lows and one to drive the highs, would this work and be ok? Would I have any common ground issues? Thanks in advance.

stubby

That should work. And remove the jumper wires that connect the upper and lower terminals. If you had no common ground issues with your single amp set-up, you should be fine.

stubby

falconcry72

When you say that vertically the amps would be acting as mono blocks, is that because you'd run them bridged? You can run them vertically while keeping them stereo instead of bridged. Y-splitter out of each channel of your preamp into each channel of the poweramps. Again, remove jumpers. The advantage to doing it vertically like this is that each amp would be powering the lows with one channel and the highs with one channel, so neither ampo would have to power boths speaker's lows with both of its channels, as would happen if you did it horizontally. The disadvantage is that if the amps have aged differently, there would be a difference in sound between channels, whereas horizontally they'd still sound the same. I typed this fast cuz i'm at work hope it's not too muddy. lol.

Dawgfish

Thanks y'all. I have already disconnected the jumpers as I'm running dual runs of Analysis Plus Oval 9s on them. Actually I'm good to go with these because I have two identical power cables, interconnects, tube compliments, and speaker cables. I think I'm going to buy the second amp and give it a try.

Schurkey

falconcry72 wrote: »

When you say that vertically the amps would be acting as mono blocks, is that because you'd run them bridged? You can run them vertically while keeping them stereo instead of bridged. Y-splitter out of each channel of your preamp into each channel of the poweramps. Again, remove jumpers. The advantage to doing it vertically like this is that each amp would be powering the lows with one channel and the highs with one channel, so neither ampo would have to power boths speaker's lows with both of its channels, as would happen if you did it horizontally. The disadvantage is that if the amps have aged differently, there would be a difference in sound between channels, whereas horizontally they'd still sound the same. I typed this fast cuz i'm at work hope it's not too muddy. lol.

If one amp powers one channel (one speaker) and the other amp powers the other channel/speaker, the effect is the same as having two monoblocks--there's no way for the SDA energy to return to the true ground at the other amp.

That would require either an AI-1, or (in some cases) the amp chassis can be strapped together. Bridging the amps isn't required for them to be essentially the same as monoblocks in regard to the common-ground requirement; although it'd take twice as many bridged stereo amps to biamp a pair of speakers.


Using one channel of an amp for the mid/bass of one speaker, and the other channel for the mid-bass of the other speaker means the SDA energy can dissipate via the common-ground of the single stereo amplifier chassis. Since the treble isn't shared on the SDA cable, there's no requirement for a common-ground on the high frequency amplifiers. Used like this, overall speaker current is doubled, voltage remains about the same. Won't play any louder; if adequate current is already being supplied, it's probably not going to make a lot of sonic difference. If the amp is marginal on current, could result in improvement.

Mr. Bubbles

I have no experience with the amps you mention and would normally agree with Shurkey that it would make little difference (that is if done passively as you describe). however, I have heard how this effects the sound with Adcom GFA-555II's and sonically it is pretty big when biamped passively in the horizontal configuration on SDA SRS's. I wouldn't have imagined the sound improving much but it did, in a big way. i say give it a shot. Good luck and enjoy

drgalexo

What year SRS2's do you have? Mine only have on positive and one negative terminal on each speaker. If you don't have a common ground you could have a problem, I blew 3 of the SDA drivers with monoblocks.

Schurkey

Blade/Blade SRS 2 (based on SDA 1B) has single pair of binding posts.

Pin/Blade SRS 2 (based on SDA 1C) has dual pairs of binding posts, with jumpers.

Dawgfish

Yeah I've got the pin/blade version with the dual binding posts. I believe they were manufactured in 88. The Amp-1 is a common ground amp. I am currently using one to power my SRS 2s and it sounds great. I figured if one sounds good.............Anyways I'm still going back and forth on this, but I'm leaning towards trying it.

drgalexo

The pin/blade models are 1987 and later, they are more forgiving amplifier use, unfortunately I have the blade/blade from 1986. They still sound great but have to have a common ground amp. Thanks for for the info Schurkey, I didn't catch that in the SDA manual.

gp4jesus

Like mono blocks, a vertical configuration wont have cross talk between the LR. In theory you should experience better channel separation. DC offset and bias settings could affect the results. Either way YMMV.

I'm considering vertical (active) tri-amping for my final LR* configuration so I'm VERY interested in your results.
* conventional Polk towers

Merry Christmas, tony