Axiom Home Page Forums General Discussion Stereo Dual Amp vs. More Wattage?

I wrote to Andrew and didn't get any response. I called Axiom and nobody got back with the answer. I tried to write to Ian and still waiting. So I'll ask here to see if there is any reasonable supported response.

I have a set of M3 speakers that have ended up in my small office to hook up to a couple of computers.   I have gone out and bought a Fosi Q5 DAC that has both headphone ports and RCA outputs that makes it convenient and perfect to act as the sudo pre-amp selector. Headphones when I need to be quiet, and running the M3 when I want to get a bigger sound.

I have a pair of AudioSource Amp One/A that I can use to power the M3.  These amps can be configured one of two ways.  As I have two of them, I can either set each of the units up in bridged mode to combine the left and right channels to give me 180watts of power each side @ 8ohms. This is the high wattage option.

But as I always order my speakers with the dual bi-wire binding posts, I can remove the metal bridge plate from the speakers, and run a pair of RCA splitters out to the L+R inputs of each of the amps and use each channel to dual amp the M3.  this would effectively give me 80watts+80watts @ 8ohms for each channel. driving the woofer and tweeter separately on their own amp channel. I don't know if you can technically add the two amp channel power together as you are driving each channel full frequency but only using a part to drive either the woofer or tweeter.

Now I don't know if bridging the two channels gives you as clean wattage power as running the two separate channels. I am sure that there is a +/- to each of the options. What is the advantage to each way?  I just happen to have the 4 channels worth of amplifiers going unused with the pair of Amp One/A units that was originally bought for Atmos that I know I will never use, and a pair of M3 speakers that would really prefer to get connected to a real amplifier rather than the pretend 100watt Pioneer AV receiver that they were previously hooked up to that made them sound listless and missing. With the old Pioneer it sounded like the middle of the sound was missing. I currently have tested the M3 with the Amp One/A in bi-amp mode and they sound great.

The advantage to bridging is more dynamic headroom. You will never need 180 continous Watts but you may need 180 peak Watts so you'd be covered. Then again, you're in an office and may never need that much dynamic power. The disadvantage to bridging is only known by the manufacturer. Bridging may increase distortion although this increase may not be audible.

Bi-amping may make the M3s sound better. But then you'd have less dynamic headroom. You will never need 80W for the tweeter but you may need more than 90W for the woofer.

See?

BTW, I am still in heaven with my actives. Glad I was patient and didn't let Ian sway me with passive LFRs. Although admittedly, it would have been cool to have experience with both.

With consideration for what you had posted, I figure I'd do some testing myself and give some more details to what I have found.

I took the time to re-connect the gold jumper blocks back onto each of the ports on my M3 speakers. Then I setup each of the Amp One/A to run in bridge mode by sliding the selector at the back of the unit to the correct mode. Re connected this time a single cable to the bridge output +/- on the amp and corresponding terminals on the speakers.

What I found was rather interesting for me anyways. The volume that I got from the speakers was less with the amp set into bridge mode. To compensate for this, I had to turn up the volume on my Fosi DAC that in turn made it so if you plugged in a set of headphones, you would need to turn it down by almost half or blow your eardrums out. Clearly this setup isn't desired. As for sound quality. I couldn't really hear any difference. I am wondering if this is what you meant by dynamic range, in it the sensitivity of the volume is not as great on the bridged meaning you can get more accuracy in the volume level desired as the volume dial seems less sensitive.

I think I will prefer it as dual amped for me. I will give it a try for a week and see if i like it. Then go back to the dual amp setup and see if that meets me needs better.

No, this is not what I expected at all. I would check that you wired the input correctly. Only one channel ought to be connected per amp of course but I don't know if you should be connected to the left or the right on each one. Or perhaps you didn't wire the speaker correctly for bridged? You may want to confirm with the manual.

If I designed a bridged amp, I'd use the right channel input for bridged mode. And the two plus outputs would go to the speaker. Try that if you can't find the manual.

The manual is easy found on the web and I had it configured correctly. I don't know why I get those results. But I went back to Bi-Amp and it sounds much better for me, so that is were it will be I guess. Can't fight want just sounds right.

Perhaps bridging is increasing distortion. Are the M3s pre v4?