Review: Harman Kardon avr2650 Multichamp


Category: Amplifiers

The big gift under the Christmas tree this year with my name on it turned out to be a Harman Kardon avr2650 7.1 95wx2. My sister informed me that it was my access to the internet--an intimidating thought. In my entrenched 2-channel universe, my idea of an avr was to use it for biamping, triamping--you could quad-amp with subs.

So I started by setting it up as 2-channel with the biggest vintage AR's I thought it could handle--the 93 3-way floorstanders with four drivers at 6 ohms, 87spl. I added the PDR10 V.3 subs, which are not good subs by the way but the only ones I have and used my HK HD990 cdp as source.

Dolby Volume, widely available on mid-fi avr's, was set on medium, and I left it on and left the room EQ off and was amazed by the sound quality which was preferable to Dolby Volume turned off. Highs were crisp and clean; overall sound was tight; tonal qualities became rich with break-in. And all easy on the ears. I had stopped listening to Dave Matthews "Crash" on RCA label because of the harsh edge. But Dolby Volume had the cure. Piano on Jacques Lousier Trio "The Best of Play Bach" was smooth as silk. All disks were given a more pleasant quality. I thought, I've been living in the woods in Minnesota in January too long. A mid-fi avr can't sound this good.

I went to the net in search of reality and found two reviews of the flagship avr3650. One is www.hometheatre.com/content/harman-kardon-avr-3650. The other one fell into the black hole of cyberspace. But both critics were impressed with 2-channel listening using Dolby Volume. I read, "Harman Kardon has taken the road less travelled" and "a music lover's dream". It seemed that these critics too were living in the woods in Minnesota.

I went to the Dolby Labs website for an explanation of Dolby Volume. I quote, "Dolby Volume goes well beyond providing, consistent volume level. It also maintains the sonic balance of the mix.." and provides "..what we call reference quality sound". While this description is wrapped in enigma, it implies an engineering of the signal which would then depend on the ability of the amplifier to faithfully amplify the Dolby Volume. Put another way, it gave me enough to hang on to so that I could believe what I was hearing.

It should be noted that the flagship avr3650, avr2650,and the 5.1 editions 365 and 265 all have the same owner's manual with all the same specs except for the power ratings. Even HCC is the same for all of this series at 35 amps. The newest avr1700 is a slightly different animal with THD at .1% compared to the avr3650 series at .09% and weighing a few pounds less. The buyer needs to know as well that the avr3650 series is not equipped with every available feature or every bell and whistle, for example S video. And the owner needs to know that the owner's manual supplied is abbreviated and that the complete manual needs to be downloaded from the HK website--unless the owner knows that the avr button must be pressed in order to access the menu. If the owner already knows that and is agile with these avr creatures, then maybe not.

I still haven't set up the surround. I ordered a pair of Paul Speltz' autoformers. I'm going to configure them to the maximum impedence with a larger, more revealing, more reference quality speaker--a better test. Such is the madness that belongs to my 2-channel universe.

Associated gear
HK HD990
vintage AR93Q speakers
Paradigm PDR10 v.3+

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Showing 2 responses by almarg

Beautifully done review, Lynne. Enjoy!

Regarding the autoformers, a point to keep in mind is that although chances are that increasing the load impedance that is seen by the AVR will make it possible for it to provide somewhat better sound quality (and will also, btw, reduce the sonic effects that may be caused by the speaker cables), there will be a reduction in the maximum amount of power the AVR will be able to deliver to the speakers.

For example, if you were to multiply a 6 ohm speaker impedance to 12 ohms, using the 2x impedance ratio the autoformers can provide, the 95 watt/8 ohm/2 channel rating of the AVR would be reduced to approximately 63 watts. That's not a whole lot of difference, amounting to only about 1.8 db. But if you were to use the 4x impedance ratio with a 6 ohm speaker, resulting in 24 ohms being seen by the AVR, it would only be capable of about 32 watts, a reduction of about 4.8 db.

It would be a different story with an amplifier having a tube output stage, but those numbers will approximately hold true for nearly all solid state amplifiers.

Best regards,
-- Al
Hi Lynne,
So I have 95w x 2 driving them. Right?
Yes.
Probably no one makes 4 ohm speakers anymore, but it should be against the law. They saturate amps and probably even the speaker crossovers.
Actually, there are still lots of 4 ohm speakers that are made. One reason among several being that solid state amplifiers can provide more power into 4 ohms than into 8 ohms, in many cases twice as much. Although amplifiers often will have higher distortion and won't sound as good doing so, compared to when they are working into a higher impedance.
If I take a disk with poor sound quality and burn a copy with my HP pc, the copy sounds better than the original.
That phenomenon, while counter-intuitive, has been reported by a lot of people, and can be explained in a plausible manner. See my post here.

Enjoy!

-- Al