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

Hi Rock,

This is getting confusing. The NAD C356BEE is an integrated amplifier with its own internal preamp. Why are you using an outboard preamp? Nad electronics are well-designed and there should be no need for an outboard preamp. The latter may be the source of the distortion. You could be overloading the line input of the NAD with the outboard preamp.
How do you control the volume level?
Alan

I tried with 3 apps to measure my normal playback level. average is below 80, peak at 85, not exceeding 90. Actually I quickly put it to full volume and it just reached 90 and couldn't reach higher. Since the app hasn't been calibrated so the result might not be accurate. I measured the level of a piano and also got the same range (average around 78, peak at 85)

Most of the time I feel comfortable to enjoy the music without any distortion. Just when I increase the volume out my comfort zone or the music gets too loud, then I feel the hi pitch sound is getting too high and narrow.

I use the OPPO amp to hub my CD and USB sources. It is directly connected to NAD main in and use OPPO to control the volume.

Not sure if OPPO DAC is better than my Marantz DAC, so this is an experiment for me to find out.

The EP500 has speaker level inputs/outputs, no?

I've been on this board a decade. For some time I appeared to be inactive. Little did any of you know I was lurking and taking notes on you all.

It isn't misleading. The average speaker efficiency is about 87dB and the M22s are north of 90dB. This means they produce the same sound pressure as an average speaker at half the power fed into the average speaker.

I would not trust the smartphone mic or a smartphone app for this application.

Like Alan said you may be saturating the NAD's input with your Oppo.

Try driving just a single speaker. If you are hearing distortion out of only a single channel, it could be the channel or the speaker.

Rock, I see that I responded to you here when you were first considering your setup. Although for the most part you decided to go in a different direction, I can repeat what I said there.

I, along with Alan and quite a few others are of the view that the M22/EP500 combination is superb for the enjoyment of music(probably about 99% of my listening). I see no good reason to consider the M60Ti. Keep in mind that the all-important mid-range is handled by two of the 5.25" drivers in the M22, compared to only one in the M60. This indicates greater mid-range dynamic capability for the M22 despite the(meaningless except in the low bass)larger M60 enclosure.

The distortion that you mention at certain levels(not exceptionally high levels from the measurements you made)might possibly be due to a defect in one M22 or one channel of the NAD, so the suggestion by Tex(Mojo)to try listening to just one M22 may be useful to check this possibility. Your NAD is rated quite conservatively at 80 watts and in good operating condition can drive the M22s to dangerously(to your hearing)loud levels.

The problem with having to drive the M22s full-range, which may contribute to the problem, indicates the unsuitability of the NAD(or any integrated amp without bass management circuitry for a sub and mains)for your setup. You make a reference to a coming "5.1 receiver" but give no details. If this means that you're getting a new multi-channel HT receiver with bass management circuitry you can relieve the M22s of the lowest bass burden by setting the crossover to 80Hz. This can't be done with the EP500 control incorrectly labeled "crossover", as it's simply a low-pass filter which rolls the sub off above the selected frequency, but which can have no effect on the connected M22s.

So, if you're getting a new receiver the M22/EP500 combination should continue to be excellent and it would be suggested that you use wide-dispersion side-surround speakers such as the QS8s for both music(using a surround mode such as DPLII to hear ambience from the surrounds where it belongs)and movies.

Hi Rock,
I agree with John K and (mostly) with Mojo. Given your playback levels and the size of the room, your Nad's 80-watts per channel should be quite capable of driving the M22s to clean loud levels without distortion.

Try bypassing the Oppo and using the Nad's own preamp/amp to drive the NAD and listen for any distortion. If the Nad has bass/treble controls, do NOT use any bass boost, which will increase power demands from the Nad amp significantly.

By the way, there are NO audible differences between modern DAC converters. Measurable differences may exist but at levels of -80 dB or greater. Those are totally inaudible to human hearing with music programming.

As to misleading statements, I do believe in buying as much power as you can afford, to eliminate the possibility of driving an under-powered amp into clipping distortion. I do not endorse the use of tiny tube amplifiers with any speakers. Those tube amps routinely generate distortion well into the audible realm (1% to 10% or more), and have many other liabilities.

I agree the dB meter apps should be calibrated. The one I use was off by almost 10 dB until it was calibrated. However, the levels you measured seem quite accurate for comfortable listening levels in a domestic environment.

Alan

Thanks everyone for the help.

I did some tests:
1. CD-preamp-amp main in: drive one channel and two. not much difference
2. CD-preamp-amp line in: getting better, more control. one channel or two, not much difference.
3. CD-amp line in: even better. can go higher volume without feeling strained.

Questions:
1. So NAD amp can handle the incoming sound well with its preamp than Oppo, correct? Would NAD soft clipping feature distort the sound so I shouldn't enable it?
2. I could try with Oppo bypass mode (need firmware upgrade). if so it is still a good hub for all of my sources?
3. If M22+EPC500 is a good combination without huge investment on high end floorstanding speakers, then next step should be upgrading the AMP. What would be the recommendation? An AMP with sub pre-out and high power (>175W)?
4. Since my main interest is music (classical and jazz), so integrated AMP still is my preference. JohnK suggested that I might look at a high-end av receiver for both music and movie. However I read some articles talking about the 2 channel amp is still better than same priced receiver. It could be also integrated with home theater system to drive only the front speakers. Is that right? Check this link just for a reference: http://www.hifihunter.com/articles/improving-stereo-performance-surround-sound-setup-part-1/
5. When it comes to the AMP, any suggestions? Yamaha A-S801B/S? NAD?

Too many questions:)