Topic: Shure Surround Processor HTS5000

[scervin]

I got this thing from my parents basement.  This is a pretty neat piece of equipment.  It takes a 2 channel in and simulates 5 channel Dolby surround.  It is similar to the feature in a receiver, but you can adjust all channels, input level, etc w/o messing up the receiver settings.   Seems like a neat way to listen to some old analog.  Make an offer.

sc

[Gutbucket]

Dolby Surround = Halfler 'ambience extaction' = Mid/Side (Sum/Difference) encoder.

The Side (difference) signal is routed to the surround speaker(s).  If two surrounds are used, they are sometimes wired in opposite polarity to increase the 'spaciousness' of the ambience.  Some decoders add level adjustment, a front/suround 'mix' control, and a short delay and to tweek balance and futher decorelate the suround signal from L/R.  Dolby Surround also sends the Mid(Sum) signal to the center speaker if used. 

It's pretty simple matrix.  Often works really well with live stuff and AUD recordings IMO. 

I encourage anyone without a surround setup who has an extra pair of speakers and some speaker wire laying around to try the following:
Place the two extra speakers at the back of the room, wire the two negative terminals of the extra speakers together & the positive terminal of the Left Surround speaker to the positive terminal of the Front Leftspeaker (or amp terminal) and vice versa for the Right side.  Instant Dolby Surround,Halfler ambience extraction circuit.  I've got an old old Brian Eno LP with an illustration showing how to do this on the back, using a single surround speaker (two wired as described above work better).  Be smart, whatch the impedance and don't blow anything up, I've never had any problem trying this with lots of cheapo amps and a few very nice ones (All SS).  It's not descrete surround, so you may want to point the surrounds at the ceiling, at the back wall or corners to bounce the 'extracted ambience' around and limit the direct sound from them somewhat.

The beauty is that it's totally simple.  Using less efficient surround speakers is best since there is no front/rear level control.  There is no additional decoding circuitry and the same amp drives all the speakers.  I often like it beter than modern surround decoders for stereo recordings.  I also find it quite interesting and informative to listen to the difference signal of my recodings up close to the surrounds.

Scervin's box makes it simple to balance the levels and switch the surround/ambience extraction in and out.. It may or may not include Dolby ProLogic which tries to steer the loudest sounds between the front 3 speakers which isn't a great idea for music (so just leave the center disconnected & off), and probably needs an additional amp for the surround speakers.

I may be interested since I've been thinking of DIY'ing something for speakers in my back yard..

Scervin, can you tell if this thing adds delay to the surrounds, runs ProLogic (and if it's defeatable) and if it has RCA line level outputs for surround & center out?

[scervin]

I don't think it is pro-logic, it only says Dolby surround.  It has 2 channel line level in and 5.1 line out.  The channel adjust is by little turn pots under the unit.  It has 16-36ms delay and has stereo out, mono, and defeatable surround.  A google search may get you more info.  I'll probably play around with it this weekend.