Axiom Home Page Forums General Discussion Technical Questions 1400-2 Amplifier stample with 1 or 2ohm load?

It would be nice to have a centrally located amp, and preamp to run a whole house audio system. The only other thing that is needed is a switch (and the speakers for each room). Many of these switches come with impedance matching so that your amplifier isn't presented with a load that it can't handle. But, the 1400-2 amp is stable with low impedance loads, so it would be nice to be able to avoid impedance matching and have better audio fidelity. My question is how low can you go?

For example if you have eight 8 ohm speakers in parallel that would be a 1 ohm load. If you had some 4 ohm speakers mixed in there you could dip down as low as 1/2 ohm load. Would this be stable with the Axiom amp? If so, is it stable because it is a digital amp, so other high-end digital amps could do the same?

The problem I see is speakers do not just run at 8 or 4 ohm, there will be dips that I would think would present any amp with shut down and or heat over load issues.

The problem is when impedance drops in half, current flow doubles. If the 1400 is producing 1400 Watts of output at 4 Ohms, it'll be 2800 at 2, 5600 at 1, and 11200 at 1/2. There's no way any part of the amp could stand up to those levels.

I don't know why you'd select such an amp for whole home audio, it really isn't suited to the task, unless you're running M80s in every location.

Whole home audio is at odds with fidelity from the start. But if that is the goal, I'd get a pre-amp with balanced outputs, split them with gear designed for the job (not just Y-cables), and do the runs with good quality balanced cables. Then stick amps in each room with speakers, and turn them on and off where I wanted sound or not.

Or get a distribution amp designed for the task (like the ATI AT 6012 http://www.ati-amp.com/at6012.html ), and use individual speaker on/off switches, not the multiple selector.

Outlaw is selling their old pre-amp right now as B-Stock for $400 which would be nice for this option. But, it seems like the cost of amps in each room would start to add up quickly. The nice thing is that you don't have to worry about a switch though. Like you said I could just turn on the amp in the room where I want the sound.

Does anyone know if an amp like this is good quality?

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=245-500#windowcontent

I know Crown is a good brand, but I'm not sure about their budget stuff.



The amp suggested here is about $2000. You still need a pre-amp. But, just on/off switches in each room after that. It seems like the Crown amps in each room would be about the same cost, after you factor in all the balanced cables needed in the first option.

Did you see the price of the A1400-2? I assumed cost wasn't an issue if you were thinking about using it. Hint: $2650, plus you'd still need a pre-amp.

I really don't know anything about the Crowns. But the ATI is a really good quality amp, although it's only about 100 Watts/channel into 4 Ohms; a little more than half that into 8.

Yes, I saw the price of the 1400-2 and it is definitely more than I want to spend. I just remembered seeing specs on the website that it was rated for a 2 ohm load and thought that maybe it would be stable below that. And if the Axiom amp was stable for something below 2 ohms then maybe I could find something cheaper that would be as well.

The most that I would probably want to spend for everything but speakers would be in $1500 to $2000.

It's too bad that there aren't more options like this, then you wouldn't need a pre-amp at all.

http://www.casatunes.com/products/xli.html

I read a review of the software and it seems like it can't do Pandora. Also, a higher quality output would also be nice, but Casatunes seems to be the only option like this that I could find. It's too bad Apple doesn't get into this so that we could get a nice intuitive solution. If we could get a high quality sound card with the ability to send different sources to each room with nice easy to use software at around the price Casatunes is selling this for, then it would be the goto solution for a whole house audio hub.