Erin's review of McIntosh MC462 power amplifier

[Oddball]

Definitely not an engineer or expert, but long time user, now mostly focused on HT. Couple of points.

95dB is not really that loud for peaks. Some peaks last longer than the others. If you listen at 85dB reference level HT material, your peaks could actually hit 105dB, especially if you run your speakers as large.

I have always wondered if the test signals actually capture the whole story, especially with any given speaker load at low frequency. If you have a 30hz peak (or even better more peaks below 100hz) that is 105dB, how would you fit that in the charts? If one had the REW compression charts for that signal from both amps perhaps that could shed some more light to what's happening?

 

[kyuu]

95dB is not really that loud for peaks. Some peaks last longer than the others. If you listen at 85dB reference level HT material, your peaks could actually hit 105dB, especially if you run your speakers as large.

Right, but I don't believe Erin was testing at 95dB peaks, he was testing at 95dB average SPL. Unless I misunderstood?

 

[Soniclife]

I might suspect the auto-former is audible at power. These only give constant power at constant impedance. Speakers are not constant impedance.

The 888 are well behaved in the audible range.

 

[kyuu]

The 888 are well behaved in the audible range.

They seem to be between 6 and 10 ohms for most of the audible range. That might actually support that the autoformer is making a difference, as the McIntosh would be able to put out more power at those higher impedances than the March Audio I believe.

 

[Oddball]

Right, but I don't believe Erin was testing at 95dB peaks, he was testing at 95dB average SPL. Unless I misunderstood?

Will need to watch the whole thing and take a look at his review as well.

Music does not really have set dB range as soundtracks do. For 95dB soundtrack level, that would be +10 reference volume, with peaks of 115dB for mains and 125dB for subs.

My system is not too shabby, but could definitely not deliver these levels even if Macs and all components were sprinkled with wholly audio water. For that SPL one would need to look into pro audio solutions and an army of subs.

 

[Old_School_Brad]

Right, but I don't believe Erin was testing at 95dB peaks, he was testing at 95dB average SPL. Unless I misunderstood?

95 dBA average is definitely loud. With some material, the peaks can easily exceed +20 dB unweighted, putting the speakers at risk of non-linear behaviour and the amplifier on the verge of clipping and audible distortion.