We could probably have a pretty full discussion just on test tracks and why we use them. Of these you mention, only the Steely Dan one do i have.
Here a few I use:
Edie Brickell & the New Bohemians - Air of December
Conqueror - No Photo
Aries - It Struck Me Every Day (a very ambient intro and finale)
Alan Parsons - Tales of Mystery and Imagination (any track)
Rita Wilson - Wichita Lineman & Never My Love (for exactly centered clear vocals)
Nil - Derives
and several dozen more...
This might help
Though I think they use the signal they get out of the transformer to feed a bridgeable amp. Lots of those in the Car audio world, where almost any amp is bridgeable, you've got to check if you have one though.
I've looked into it but found out my head unit was able to supply me with L-R. I just lacked the time delay I needed to make it work.
As this is a secondary and separate setup from your mains, you might just want to try a PC in between the amp and input signal, you get another AD/DA step but you can safely make the signal work.
You'd only need it for the ambient test. worry about a more definitive solution if it works out. Install JRiver 30 day trial on it and you have all the power you need to change that ambient signal any way you want, including adding reverb or time delay, EQ, FIR, mid/side processing, you name it. For a test it would probably be the easiest and safest way.
Though I think they use the signal they get out of the transformer to feed a bridgeable amp. Lots of those in the Car audio world, where almost any amp is bridgeable, you've got to check if you have one though.
I've looked into it but found out my head unit was able to supply me with L-R. I just lacked the time delay I needed to make it work.
As this is a secondary and separate setup from your mains, you might just want to try a PC in between the amp and input signal, you get another AD/DA step but you can safely make the signal work.
You'd only need it for the ambient test. worry about a more definitive solution if it works out. Install JRiver 30 day trial on it and you have all the power you need to change that ambient signal any way you want, including adding reverb or time delay, EQ, FIR, mid/side processing, you name it. For a test it would probably be the easiest and safest way.
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It seems you are rediscovering the Hafler setup for ambient surround. I have used it on and off since 1981. I rediscover it every now and then and enjoy it until I make a major change to my system and stop using it for a while.
I posted a simple way to create the back channels and frequency contour them using a Lepai 2020 for Hafler surround. It seems that we came to about the same conclusions regarding frequency response and level for the rear channels. It always seemed to be a much more natural sounding and unobtrusive alternative to the various Dolby surround systems that I had tried.
Marc
I posted a simple way to create the back channels and frequency contour them using a Lepai 2020 for Hafler surround. It seems that we came to about the same conclusions regarding frequency response and level for the rear channels. It always seemed to be a much more natural sounding and unobtrusive alternative to the various Dolby surround systems that I had tried.
Marc
In a way we are, but it has to have the right amount of delay added to get the most out of that Hafler circuit. If you do it right, you won't notice it's there, until it gets turned off. The added reverb also helps to get it a step up.
I've read a lot of things on Dolby etc... but never any clear praise for 2 channel music, except the pro logic IIx I think it was. A lot will have to do with the room and other variables. But I think Logic 7 may be a step up from Dolby.
But this simple Hafler trick isn't bad at all, provided you have the means to do the time delay. Without proper time delay it get's old fast i.m.h.o.
That Lepai trick could work for any amp that will let you wire the +'s and -'s together like that. Is it amp dependent or what?
I wouldn't have tried it with a more expensive amp, but I risked it with the Lepai. It seems to work fine for me (YMMV).
It won't work with a non-bridged amp because both - terminals are at ground, and it might not work (and lead to damage) with a class D amp that takes its feedback post filter. Since the Lepai takes feedback before the output inductors, there is a degree of isolation between the output terminals and the input to the amplifier.
Marc
It won't work with a non-bridged amp because both - terminals are at ground, and it might not work (and lead to damage) with a class D amp that takes its feedback post filter. Since the Lepai takes feedback before the output inductors, there is a degree of isolation between the output terminals and the input to the amplifier.
Marc
In case my brother isnt sure, how would one go about being absolutely sure?
Dayton Audio APA100 Class AB Stereo Amplifier 60 WPC
This ^^^^ is the amp I am using for my ambient channels. Its bridgeable, but I use it in stereo mode. Class A/B operation. I guess I could call PE? Dayton?
If it is a bridgeable A/B amp, it most likely has a bipolar supply and common - terminals on the outputs.
I would put 100 ohm resistor from each amp + terminal to its minus terminal (just to give each amp channel a common reference and load to ground), and then connect the two speakers in series (back to back: L+ to the left speaker + terminal, left speaker - to the right speaker -, and the right speaker + to the R+ amp terminal). Left speaker will play L-R and right speaker will play R-L. That should work without putting too small a load impedance on the amp.
I can try it tonight on one of my older amps to check, but I think this is pretty safe to try.
Marc
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Thats a different wiring scheme than here: Simple Halfler surround setup - Techtalk Speaker Building, Audio, Video Discussion Forum
It's different because they are different amps. Each channel on the Lepai is bridged internally to get reasonable power from a 12 V supply, so the + is swinging higher from 6V and the - is swinging lower from 6V on a + input signal. The APA100 is more conventional. I can draw up the second when I get home.
Hope you'll find a way to test it Jim. It took me by surprise compared to my earlier test.
It's good to try and revisit things sometimes...
It's good to try and revisit things sometimes...
Me too! Talked to my brother and he thinks it will work also, not 100% without seeing a wiring schematic though.
I am still a bit confused about the actual wiring from the amp to the speakers though. Hopefully, msibilia will clear that up later.
So the amp remains in stereo mode, not bridged mode for this, right?
Marc, have you ever tried using the L-R and R-L delayed by about ~20 ms behind the main signal? Preferably also band limited etc.
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Yes. Otherwise, the two outputs wouldn't have the two different signals that allow the subtraction to take place.
Marc
Yes, without the resistors it's how I hooked up my rears to the head unit in my car. The absence of proper time delay made me abandon it after a while.