If I understand this correctly, since the preamp doesn't do the processing, the only way to get the full benefit of SACD is analog and let the source do the processing. If that is true then bass management must be done through the source? Will optical out from source to preamp pass the processed signal so that bass management can be done in the preamp? Thx
You are correct.
SACD is basically hobbled. To make it work correctly you have to do some workarounds usually. There is bascally no bass management, and my classical SACDs do not have a subwoofer channel. They have two, three or five channels of full range audio. And remember for SACD the rear speakers must be in the rear corners.
There are a lot of players that actually convert from a crude processor to PCM. This may or may not be disclosed. I do not know of any receivers or preamps that do DSP, bit there may be the odd one out there. I think this is why SACD is slow to take off and may be never will. All this goes a long way to explain why many can not tell the difference from CD.
This is my solution to SACD replay.
Now truth in advertising. My system is highly atypical, and there is no commercial system remotely similar. It is hard for other members to get their hands round its deign concept and execution.
Here is the picture and details. It is a 7.1 system that has a total of 1.7 KW of audio power from 14 amplifier channels.
http://mdcarter.smugmug.com/gallery/2424008#127077317
First the left and right speakers. The MTM array with the two 6.5 inch magnesium alloy cones and tweeter are in a TL with an F3 of 44 Hz. These act as the left and right speakers, and are set to large. The power is 240 watts to each.
Now the bass lines have an F3 of 27 HZ. Each contains two 10 inch magnesium cone woofers. Each 10 inch woofer is connected to a 100 watt amp. The upper woofer is fed a signal from the front left right via an electronic crossover that takes the bass all the way down but has a correction for the diffraction loss of the 6.5 inch bass mids. The lower 10 inch woofer receives the bass from the Rotel crossover set at 100 Hz, and of course a portion of the bass from the other channels. The drivers are from the SEAS Exel range of drivers.
The center speaker contains two SEAS coaxial drivers. Only the lower driver has the tweeter connected. The crossover is passive. The top driver is fed from an electronic crossover the diffraction correction and the bass all the way down. It is a small TL design with an F3 of 47 Hz. Each driver is fed from a 100 watt amp. This speaker is set to large.
The rears are minimal ripple closed box with 2.5 way passive crossover including diffraction compensation. The F3 is 53 Hz second order roll off. The drivers are Dynaudio. Each is driven by a 100 watt amp. The speakers are set to large.
The rear backs are dual TL design. They are biamped. The lower lines have an F3 of 35 Hz and each contains two KEF B 139s. The upper line is a three way passive using Dynaudio cone M75 and Dynaudio midrange domes and tweeters. Each speaker is powered by two 100 watt amps. These speakers are set to large. The speakers are voiced to the space.
Now back to SACD. I don't know of a preamp that decodes DSP. So the SACD player outputs an analog signal. In the Rotel, and I think this is usual, this is handled as pass through except for volume. None of my classical SACDs have a sub channel. They are either two, three or five channel. The Rotel outputs the rear channels to the center back speakers not the rears (side), which is correct for SACD. There is no output for a sub. I have a switch that disconnects the Rotel sub output and puts the amps for the two lower 10 inch woofers in the left/front lines in parallel, and feeds them both the signal from the external electronic crossover of the front left right speakers.
So when I listen to the SACD of the Klais organs of Cologne Cathedral the rear divisions come in full force.
I think the correct set up for playing SACD is problematic. I have found that this arrangement works very well, but I'm curious to know how others handle it.
I have been very pleased with the performance neutrality and realism of this set up. It is very very close to being there. And the rig is not all fussy as to program.
As you can tell, I have an antipathy to separate subs, and favor an integrated approach. Garry Gallo's ref. 3s take a slightly similar approach in that the woofers in his left rights have dual voice coils. One voice coil of each woofer, can be fed the LFE channel from a separate amp. So he has an integrated system. However I did mine first.
