Axiom Home Page Forums General Discussion Advice from Axiom Owners M60 Ti vs v4

My bet is you are taxing your NAD. 80W/channel isn't enough for you. Play just a single front channel and see if the distortion improves compared to 2 channels.

More sensitive speakers could do the trick or a bigger amp. Good luck finding more sensitive speakers than the M22s.

Also try crossing your sub at a higher frequency to see if it improves distortion.

I think you are correct, Mojo, about Rock taxing his speakers with just 80 watts per channel from his NAD. I drive my M22s with 175 watts per channel, and together with the EP500 sub, they play as loud as I ever want in my 2200 cu. ft room without any signs of strain or distortion. That includes momentary peaks in excess of 95 dB SPL from my listening position about 10 - 12 ft from the M22s.

I also wonder if he might be running his M22s "full range", thinking, incorrectly, like many enthusiasts, that he'll be "losing bass" if he uses a crossover with the subwoofer. In fact, using a sub with the M22s with an 80-Hz crossover greatly eases the job of the M22's woofer, transferring the bass duties to the subwoofer. He could easily overdrive the M22s at high levels if he is running them full-range.

Alan

...I must have missed where Rock said his NAD was 80w, can you point that out for this old guy?

You maybe right. Here is the specs of NAD C356BEE:
POWER AMPLIFER SECTION
MAIN IN, SPEAKER OUT
Continuous output power into 8 ohms and 4 ohms (Stereo) >80 W (at rated THD, 20 Hz-20 kHz, both channels driven)
Rated THD1 20 Hz – 20 kHz, CCIF IMD, SMPTE IMD, DIM 100<0.007 %
Clipping power >90 W (at 1 kHz 0.1 % THD)
IHF dynamic headroom - 8 ohms +2.6 dB
4 ohms +4.4 dB
IHF dynamic power - 8 ohms 145 W
4 ohms 220 W
2 ohms 290 W
Peak output current >50 A (in 1 ohm, 1 ms)
Signal-to-noise ratio >101 dB (A-weighted, ref. 1 W)>
120 dB (A-weighted, ref. 80 W)
Damping factor >100 (at 8 ohms, 50 Hz and 1 kHz)
Frequency response ±0.3 dB (ref. 20 Hz - 20 kHz)3 Hz – 70 kHz (ref. -3 dB)
Input impedance 20 kohms + 1 nF
Input sensitivity 950 mV (for 80 W in 8 ohms)
Voltage gain 29 dB
Headphone output impedance 68 ohms
Channel separation - 1 kHz >80 dB
10 kHz >70 dB

It doesn't have sub pre-out, so can't crossover and have to drive full range. It has A+B speaker, now A to M22s, B to EP500. If I set crossover on EP500 on a higher frequency, would it help? Any other suggestions?

Thanks, I was referring to how Mojo knew that was the output spec on your NAD

So the Axiom website said:

How much power does my receiver need for these speakers?

The M22s are very efficient - you can use them with any receiver or amplifier, including a tube amp.

That is why I didn't pay much attention to the amp power. Should Axiom modify its statement which is quite misleading.

What should I do now?
Thanks Alan.

The NAD doesn't have sub pre-out, so can't crossover and have to drive full range. It has A+B speaker, now A to M22s, B to EP500. If I set crossover on EP500 on a higher frequency, 80 or 100, would it help? Any other suggestions?

Hmmm, this is puzzling. Do you have a sound level meter, or an app for your smart phone (lots of free ones available)) so you can measure what sort of playback levels you are using? The M22s will normally play plenty loud in average-size rooms like yours without distortion driven by ample power amplifiers (75 to 100 watts per channel).

You may be listening at extremely loud levels that are stressing the M22s and causing the distortion you are hearing. (Some former colleagues of mine used to listen at levels I'd call "deafening", peaks in excess of 100 dB SPL, which would cause me to leave the room.)

Since you are driving the M22s full-range, then they could be distorting at such levels, in which case, larger floorstanding speakers like the M60s or M80s would play distortion-free so long as you have plenty of amplifier power to feed them.

As a rough guide to subjective loudness levels, 80 to 85 dB is "quite loud"; 90 to 95 dB is "very loud", and above 95 dB is "extremely loud". Most people are comfortable with playback levels of 80 to 85 dB with rock or classical music, with occasional peaks to 90 dB or so.
Changing the crossover on the subwoofer won't help matters for the M22s since you are driving them full-range from your Nad's amplifier output.

Alan

Hi Alan,

By the way, I am using a preamp. Would that help to offload a little bit?

Thanks.