Axiom Home Page Forums General Discussion Technical Questions From a 1909, how much better SQ to 2809. To 3808.

Did I just hear the sound of a can opener and wrigling wroms?

Not fish'n season yet, keep the worms in the can for a few more weeks.

OK, I'm with you Charles. I am sooooo confused. Bringing THD into the conversation seems like an important factor not really addressed on this (threads) discussion.

The question was specific to SQ improvement with one Denon receiver verses other Deonon receivers. This string immediately derailed to the never ending wpc debate, which has little to nothing to do with SQ.

You most likely would not notice any difference between all the models you are considering, provided that they are all set up identically.

I would concentrate on each model’s functions and compare them. One may have features that appeal to you more than others.

For example, if one has independent crossover adjustments, and one has a basic global adjustment, the one with independent may very well improve overall SQ as you will be able to tailor each channel how you prefer.

Compare the features and forget about WPC. If you find that you need more power, stop looking to receivers to supply that and look at external amplification. You will have to spend a lot of money on a receiver to get you in the 200 WPC range, which is where you will start to notice a difference.

Yes, Charles; it appears that you do have several misconceptions with respect to amplification, particularly as to audibility of distortion and what clipping is. There are no "undistorted watts", the question is how many aren't audibly distorted. In listening to music, tests have shown that distortion has to be more than about 1% to have audible effect. For example, in FAQs Yamaha applies a "less than 2%" standard. Arguments we've seen on other boards anguishing over whether a .05% THD rated receiver sounds better than one rated at .09% lack any sense of reality.

Clipping is distinct from distortion, although at actual clipping distortion would be quite high, at least several percent(without defining "several" too closely, since it can vary). It therefore occurs well after the onset of audible distortion and is evidenced on an oscilloscope by the flattening of the top of the sine wave. Magazines which use the term clipping at 1% or even lower, when apparently they actually mean distortion at an inaudible level, are a source of confusion if correct audio terminology is to be employed.

The calculations done for Dave were simple and quick. The anechoic sensitivity of the M80s(room contribution is accounted for differently here)is given by Axiom as 91dB, while the NRC, apparently measuring a different range or other factor, gives 89.5dB. Using 90dB at one meter the typical in-room results for home listening rooms would decline at about 3dB per doubling of distance, taking into account both direct sound and room contribution. This has been researched and Dr.Toole discusses this in his book. Therefore at the 12' distance Dave specified there would be about a 5dB drop from the one meter measure, to about 85dB for 1 watt. Hence the supplied numbers of about a tenth of a watt for the specified 75dB level and 100 times higher to allow for a 20dB peak on the most dynamic of material,(such as some of the classical recordings which I have)to about 10 watts. Also the follow-up number of 104-105dB for a peak using about 90 watts is similarly calculated. These levels are of course those for long-term home listening at home with a view to avoid permanent hearing loss, not those occurring at the recording site.

The linked lab tests on the 1909 confirm its excellence, including the 4ohm measurements. The comments of the reviewer on this point aren't explained and appear to be somewhat nonsensical in that they directly contradict the measured results. If the 140 watt number at 4ohms(certainly not actually "clipping")is used instead of 90 watts, an extra 2dB could be added to the calculation, i.e., now 106-107dB.

... and the worm wranglers arrive right on que. Howdy boys.

What was that you were saying about fishing season Adrian?

Dave, it took me a while to sort through all this stuff. There is a lot of fud out there.

There are some very good articles in Axioms library. One in particular covers an experiment where Axiom tested peoples sensitivity to distortion at lower frequencies. The conclusion is quite interesting.

After a pm from Dave, to be clear, I was not trying to imply that either John or Mike were being in any way misleading etc, just that the topic can be confusing and complicated.

Features MultEQ XT versus MultEQ in AVR's
Filter resolution (satellites) 16x (2x for MultEQ)
Filter resolution (subwoofer) 128x
Number of Measurement Positions 8 (6 for MultEQ)
Adaptive Low Frequency Correction Yes
Crossover, Polarity, Delays, Levels Yes

In brief...yep.