I’ve been reading with interest about the BSGT QOL Signal Completion Stage that has gathered rave reviews for the past year. I even heard it at a friend’s house and could definitely tell that it was enhancing the soundstage of many (but not all) recordings. Then I ran across this post/review by Bruce Brown on his Pro-Audiophile forum:(
http://www.whatsbestforum.com/showthread.php?4384-Stereo-Field-Processing ). He mentioned how he could replicate the QOL effect pretty closely with some basic mid-side processing.
Well heck, I can do that! I use Jriver as my music server software (
http://www.jriver.com) and one of its cool features is the ability the use third-party VST plugins. Plugins are software programs used in digital audio workstations for recording and mixing music. Instead of patching an analog box (compressor, EQ, de-esser, etc) into an analog mixing console, a plugin is used to perform the same function in the digital domain. There are a number of no-cost mid-side plugins available for download, so I can try this for free!
So what is mid-side processing? It’s a way of converting a stereo signal into a mid (or common) channel and a side (or difference) channel. The mid channel contains all music signals that are common to both left and right channels. The side channel contains all the music signals that are unique to either the left or right channel. Once a stereo track is converted to mid-side, the balance between the mid and side channels can be adjusted to edit the stereo soundstage. The track can then be converted back to stereo to hear the new soundstage balance. A true mono signal is all mid channel and no side channel. Mid-side is the basis for just about all the stereo processing boxes that have come and gone over the years (Carver Sonic Holography, Dolby Surround, Q-Sound, SDS, etc.) It gets a bad rap because the effect is usually too exaggerated to sound realistic or musical.
Back to Jriver. I downloaded a free mid-side plugin called Voxengo MSED (
http://www.voxengo.com/product/msed/) and placed the MSED.dll file in Jriver’s Plugins folder. In Jriver’s DSP Studio I added the MSED plugin to the DSP list, checked the MSED box to activate it, and set the Mode to “Inline”. This way I could hear mid-side balance adjustments on the fly. Jriver processes the MSED plugin at the file’s native sample rate and at 64 bits of resolution. It worked on every PCM file I tried up to 24/192, but not on DSD files. I played around with it for a while, muting, swapping, adjusting, etc., just to get a handle on what it was doing. Big changes really screwed things up. No surprise there. But it helped me understand what the processor was doing to the stereo program.
What I found was that a small increase in side volume, between 1.2 and 1.5 in my system, really helped the soundstage bloom on many recordings. Any less than that and I couldn’t hear a difference. More than that and it started sounding too phasey and exaggerated, like that bad “concert hall” setting on a cheap home theater receiver. But when it was just right, I heard a soundstage to die for; wide, deep, airy and expansive while maintaining instrument placement and timbre. It’s the kind of improvement that many audiophiles spend megabucks trying to chase down. I don’t know if this is exactly replicating what the QOL processor does, but I like it and it’s easy to turn off if I think it’s getting in the way of the music.
If you decide to try this, here are a couple of things to keep in mind. If you are obsessed with things like “bit-perfect”, “no unnecessary processing”, “only as the artist originally intended”, or “my favorite reviewer or manufacturer doesn’t recommend this”, then don’t even attempt it. Your psyche is too fragile and this will just add to the high levels of audiophile anxiety that you already live with. If you do decide to bravely move ahead and try it, keep an open mind and plan to experiment a bit. The effect is very system and program dependent. Adjustments will be quite moderate and subtle, otherwise it will sound like just another gimmicky audio processor. The important thing is to have fun with it and find a balance that works for you. And if it doesn't work for you, just uncheck the MSED box in DSP Studio and move on.
Russ
