Adding center channel to a 2.1 system

[orbit1]

What electronics would be needed to put a center channel in my stereo that I use for my television when I watch ballgames in with one channel in reversed stereo for added ambiance. I know I need a speaker and amplifier, but what is the best way, if there is one, to synthesize the center channel?

[orbit1]

No help? I'm serious. I am running a Soundcraftsman preamp/eq, highly modded Hafler 200, JBL 4412's and a DA sub. I really would like to add a center channel when in "stereo reverse" mode to fill the center void. I don't know how to do this. ANY advice would be appreciated! Thanks all!

[fbov]

This is a common question, and you're not going to like the answer. Older 2-channel systems don't comprehend surround sound, and so don't synthesize a CC or surround signal. You need a different pre-pro...

And you'd need to let it do all the processing - speakers in phase.

HAve fun,
Frank

[djg]

Kind of depends on what you have for the TV sound source. If you have a modern cable box or even OTA digital for your TV signal, then a modern AVR or Pre/Pro that processes digital sound is what you need. An AVR with pre outs would allow you to use your old stereo amp. I'll put in a plug for the Outlaw Audio monoblock amp if you need one center channel amp.

Do you have a bluray player? I'm thinking no.

An older Dolby Pro Logic AVR will give you a center channel, but will only accept analog inputs.

Some people insist a center channel is unnecessary.

Finally, DON"T DO THIS. In the old days, some people would put a third speaker across the plus L & R speaker leads. It would be a "difference" channel. Not a center channel. Depending on your amps grounding setup, it could work or destroy your amp. Again, just mentioned it as someone who reverses one stereo channel might find that of interest. Again, DON"T DO IT.

Finally finally, there's the old Dynaco Quadaptor, which synthesized two ambience channels from a stereo signal. No extra amp needed. You'll have to google that thing. Good luck.

[djg]

Hey, I looked at your other thread. Is that picture what you have now?

You know, sports broadcasts on TV have pretty nice ambiance. You might enjoy the sound. It would require some new stuff, though.

[orbit1]

I think we are somewhat missing what I want to do. I am putting one of my speakers out of phase to give the larger boom box sound only for ball games (my son goes to UA, Roll Tide). Therefore since the sound comes from "outside" the speakers, I need to fill the "sonic hole" with a center channel. This does not have to be anythink elaborate or even super high quality. Yes, that is my system, added sub. I have some junk equipment around, 6.1 JVC,etc. Thanks for the replies.

[djg]

So buy a couple little speakers and put them in the middle, hook up to your second set of main outputs. Or, just toe in your mains a bit and see how that sounds.

You're right, I don't think anyone here has an expert opinion on filling the hole in a stereo system with out of phase speakers. First time it ever came up, I'll bet.

[Herman Trivilino]

I think we are somewhat missing what I want to do. I am putting one of my speakers out of phase to give the larger boom box sound only for ball games (my son goes to UA, Roll Tide). Therefore since the sound comes from "outside" the speakers, I need to fill the "sonic hole" with a center channel.

I don't get it, either. Is the source mono? From a cable box, or OTA?

You could go with djg's idea of adding two more stereo speakers. If, for example, you've reversed the polarity on your left A speaker, you might want to try reversing the polarity on your right B speaker.

[orbit1]

I have a set of Yamaha ns500's that I could add, leaving them not reversed would be true stereo and therefore fill the hole. I was hoping for a WAF center channel setup, but, as the kids say, "It is what it is." Thanks.

[fbov]

...I am putting one of my speakers out of phase ...since the sound comes from "outside" the speakers, I need to fill the "sonic hole" with a center channel....

By placing one speaker out of phase with the other, you create a big null on-axis. All you hear is the reflected sound as the direct sound cancels. Now you want to fill the hole resulting from the use of speakers out of phase. The issue is that two wrongs don't make a right.

What you want to achieve what you describe is a DSP to provide a common-content signal for the CC and difference signals for the surrounds. Your junk equipment will do this for you.

djg's suggestion would be next, but I'd suggest very small speakers, as you may get a beneficial effect if the little speakers are only good in the vocal range, as that would mimic a real CC.

Just don't watch any games on a real surround system. They've gotten a lot better...

Have fun,
Frank

[orbit1]

Frank,etal,
Thanks for the info, I will try smaller inside speakers, AND I will stay away from real surround until my kids are through college. Again, thanks!