Tape Project Forum
General Category => General Discussion => Topic started by: jcmusic on September 23, 2009, 10:35:34 AM
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What would be the result of playing a quad tape on a 4track stereo deck? Would some of the music be lost or would it sound like a stereo recording?
Jay
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Hi Jay,
If it's a discrete 4 channel quad (4 channel, 4 track) the track layout for the front channels is the same as the "side 1" tracks of a 1/4 track (1&3). The rear channels are tracks 2&4 and in some cases will be out of phase with the fronts.
Since you have a switchable 1/4 track/1/2 track you could always do " stupid tape tricks" and give both settings a try with each example of quad tapes you come across (can't hurt).
Hopefully the layout of the tracks and the widths of the recording will match up well enough so you won't get any fringing effects on track #3 (right channel) which could raise the level by a bit. That kinda stuff might vary from tape to tape though.
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Hi Jay,
If it's a discrete 4 channel quad (4 channel, 4 track) the track layout for the front channels is the same as the "side 1" tracks of a 1/4 track (1&3). The rear channels are tracks 2&4 and in some cases will be out of phase with the fronts.
Since you have a switchable 1/4 track/1/2 track you could always do " stupid tape tricks" and give both settings a try with each example of quad tapes you come across (can't hurt).
Hopefully the layout of the tracks and the widths of the recording will match up well enough so you won't get any fringing effects on track #3 (right channel) which could raise the level by a bit. That kinda stuff might vary from tape to tape though.
Steve,
What is the alternative if what you quoted isn't how it happens?
Jay
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Some of the quad tapes that were made weren't true 4 track tapes. IIRC, these had the rear channels "derived" by use of a decoder. I never actually had one of these so I don't know the track layout on the tape. I have no idea what they'd sound like without the decoder or even the head layout needed but it was probably 1/4 track.
I know that some guys collect these tapes so you may be able to get a decoder (I know I have a schematic for building one but I'm not sure how difficult it would be to obtain the IC that is the heart of the unit). I believe they hang out on one of the 8 track forums (google quad tape).
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welcome to the dark side. i haven't ventured in yet but those who know me know what i'm capable of. i already have a very decent surround system so...
http://www.ambisonic.net/ (http://www.ambisonic.net/)
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Hi Jay,
If it's a discrete 4 channel quad (4 channel, 4 track) the track layout for the front channels is the same as the "side 1" tracks of a 1/4 track (1&3). The rear channels are tracks 2&4 and in some cases will be out of phase with the fronts.
Since you have a switchable 1/4 track/1/2 track you could always do " stupid tape tricks" and give both settings a try with each example of quad tapes you come across (can't hurt).
Hopefully the layout of the tracks and the widths of the recording will match up well enough so you won't get any fringing effects on track #3 (right channel) which could raise the level by a bit. That kinda stuff might vary from tape to tape though.
I don't know if I have ever seen a matrix encoded tape. If there ever was such a thing, it would play with something like SQ or even Dolby surround to recover the out of phase L-R info but it would be the same as 2 channel "stereo" format recorded in the 1/4 track arrangement.
AFAIK all quad reel to reel tapes were discrete quad with 4 tracks one direction at 7.5 ips. The front channels would play on a normal 1/4 track stereo head as was said above. The rear channels MIGHT combine with the front if played with a 1/2 track stereo head,which would be covering front and rear left with it's left channel and front and rear right with it's right channel. It wont hurt to try, but YMMV as to how well it works.
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I too am curious about four channel systems. Among a batch of master tapes I purchased there were half a dozen 1/4" 15ips 2 channel masters encoded using the QS system. I am very satisfied with traditional two channel stereo but these tapes seem to be exceptional performances and recordings. However, if I play these normally I find they seem to be fairly "left heavy". The soundstage is far to the left until particularly loud passages, when there appears to be equal volume coming from the right channel. It sounds to me like the left and right front channels are encoded into channel 1 and the left and right surround channels are encoded into channel 2. Has anyone tried to decode SQ tapes and just play the front left and right ignoring the surround channels? Did the decoders that were available years ago offer an optional 2 channel stereo out?