Saturday, October 22, 2011

Yamaha's uncompressed music destroyer

Two weeks ago, I purchased a Yamaha RX-A1000 7.receiver for my home theater. It replaced an older RX-V2500, which was moved to another room which was also in need of a receiver. The RX-A1000 was a floor model which came with no remote control or manual, but at one third the regular price. I setup everything, and it sounded great.

There was however one exception : an original retail CD of Zhu-Xiao Mei's Goldberg Variations, played from my trusty old Yamaha CDM-900 player, sounded execrable. Specifically, the highs of the piano in variation 1 were so exaggerated and aggressive that they almost sounded like those from an old shaky AM radio. It was so harsh to me as an audiophile, but still would have been obvious to anybody with decent hearing.

I was able quickly able to figure out that this was not due to the source CD or player : when I turned on the "Pure direct" feature of the receiver, the sound fortunately returned to what was expected. So, the degradation had to be due to some processing being done in the receiver.

However, I was running in "STRAIGHT" mode, with no DSP programs enabled. I couldn't figure out what was causing the problem. It took me a few days to figure out what it was.

Today, I received the proper remote from 1-800-REMOTES. It was time to finally elucidate this mystery.

I proceeded to undo all the YPAO calibration settings . But even after the parametric equalizer to "Flat" mode, the problem still remained. I had to dig into the manual, which I had printed from the PDF. It turns out that there are several processing options that are applied even in "STRAIGHT" mode.

One of them is the "Adaptive DRC". I disabled it. But that was not the issue.
What turned out to be the problem was the so-called "Compressed music enhancer". In my opinion, this really should be called "Uncompressed music destroyer", as this is a very unfortunate consequence of enabling it. I don't listen to compressed music, and thus cannot comment on whether it has any actual benefit.

This setting is enabled per-input, which is why I hadn't heard the problem with my other sources. And it was turned on for my "Audio 1" source to which the CDM-900's optical audio cable was connected.

The front display of the receiver shows the word "Enhancer" in small red type on the display when this is enabled. Not "Compressed music enhancer". This is a real misnomer. I wish it could be permanently disabled. If your new Yamaha receiver is sounding awful, this may be the reason why.

Overall, I want to be clear that I really love the sound that the receiver can produce once this processing gimmick is disabled. It is definitely a step up from the RX-V2500. I will be posting a full review on Amazon once I have fully configured everything in the best possible way to meet all my extensive home theater needs.

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