Axiom Home Page Forums General Discussion Home Theater Why No Love for ADA Amps ???

I the audio video tech talk, of the guides section. There's a couple of very informative articles on this matter.

Matman, your question about 1000W amps depends on a number of things. First, it depends on how loud you like it. Second is whether you listen to dynamically compressed or uncompressed music.Third it depends on how much power you can pump into your speakers before they dynamically compress.

If you listen at 1 Watt per channel nominal, which may be quite likely, at grunge music which is typically dynamically compressed, then amplifier power and speaker compression is a non-issue. But if you listen to music that preserves dynamics, like well-recorded classical or movies, then that 1 Watt is fine for a flute but you might need as much as a few hundred Watts for a loud brass and drum passage.This few hundred Watts can easily become 1000W or more if you listen at a higher nominal level.

If you had M3s, they would dynamically compress at about 150W. Each of your LFR1100s won't compress until they hit 400W or maybe even more. I would venture to say, for short dynamic bursts, the LFR1100s are good to over 750W.

Most don't need a 1000W amp but I think we all need amps with dynamic reserves. When I need a couple of hundred Watts out of my Onk, it comes out of stored reserves and not the wall. If I listened to more than a Watt nominal, I would likely need a beefier amp.

Mojo has pretty much nailed it. Really all that happens when you exceed the numbers that so often make up power specifications, either output or handling, is that time stops being “continuous”. But audio playback does not exist in a world of continuous time, it is dynamic. So what is most important when chasing a great audio experience is what happens above the continuous power rating or handling. An amplifier with good dynamic headroom can play many times its continuous power rating for short periods of time without clipping; this is critical to a great listening experience as clipping is best translated as harshness when listening. Harshness, though not pleasant at any volume level, is downright nasty at loud levels. The numbers are interesting in a large room. For example it would take around 64 watts of continuous power to achieve an average listening level of around 96 dB. If you wanted to be safe and maintain 15 dB of available dynamic headroom you would need over 2,000 watts of power available for short periods of time.

The same is true for speakers. It matters little what they can handle for continuous power, generally measured as 5 hours of modified pink noise, because we do not listen to pink noise (ok, maybe Mojo does). What matters is what happens above the continuous rating for short periods of time. We take this very seriously in the design of every Axiom speaker. It is in fact the main reason we use aluminium cones as their heatsinking capabilities for the voice coil allow for much greater power handling; both continuous and dynamic. We also make sure that Axiom speakers do not make any extraneous noises when pushed way beyond their continuous power rating. Extraneous noises from your speakers will kill a great listening experience instantly.

"It matters little what they can handle for continuous power, generally measured as 5 hours of modified pink noise, because we do not listen to pink noise (ok, maybe Mojo does). "

Unlike music, the pink noise spec is complete, correct and unambiguous. I know exactly what I am listening to and it never disappoints.

Thank you very much for the short hand, Mojo and Ian.

In regards to being able to drive a power amp to it's potential [Eg. 1volt power 2volt} From the pre output. Can you over power the power amp? Say 2volts into a 1volt or 1.5 nominal input into distortion?
Or would that be decided by the power amps inputs?
{Eg. 1volt or 2 volts maximum power draw}

You can overdrive and overload an amplifier.

If you apply 2V to an amp that is designed for 1V, you will overdrive the amp. The amp might be designed to accept up to 1V and amplify that signal linearly by say, 50 times. With 1V applied, the output at your speaker could therefore be as high as 50V. Beyond 1V, the output is amplified linearly by a factor of 50 and there are non-linear components as well that result in harmonic distortion. These non-linear components are added to the linear component and you get distortion that sounds like crap. This is called clipping because when you compare the output signal to the input signal, it looks like someone has cut the top of the output signal off.

An overload is different. If you apply a voltage that is above the insulation level of the circuit, you could get fireworks.

Thank you again for the info.

Shoot I hope I don't run into problems, as my pre/pro has an output of 2volts. And the 1250 I ordered is specked at 1.5.

The last thing I want is the fireworks from an overload.

This is my go to article for an explanation of gain for the laymen , meaning me. I don't have occasion to use the info too much and this is a great refresher.

Richard

You will have no issues what so ever. That 2 volts is at full output. My pre/pro puts out 11vrms on the balanced outputs and my amp is 1.5v input sensitivity 29db voltage gain. Volume controls are logarithmic and don't ramp up like older linear volume controls.

Really hate that about the new volume controls. I wish they went back to linear as you had far more control over volume level with them.

With the current logarithmic control, you have many rotations from silent to virtually silent. You slowly ramp up to a listening level and then it requires decimal degree rotation to get from where you want to listen to too loud.

If they did an inverse logrithmic so you go quickly from silent to a listening volume, but it takes more and more of a rotation to get much louder from that. That would be fine. But I still think the linear volume was the best