In a 2-Channel Is a Center Needed?

[CT-Seven 764]

I discussed this with a member here years ago (I thought I had a post about it but I did not) in a dedicated 2 channel setup, is a center channel needed does it offer any benefit other than widening the sweet spot?

[cunningr 49]

I would think if you added a center channel technically it is no longer a 2 channel configuration.  

[sKiZo 186]

Sure it is ... it's two channel ... with benefits!  <G>

 

I've been a quad head for decades now, and recently added a center channel using the dedicated L+R output from my Carver H9AV driving an Eico mono tuber I rebuilt and had stashed away. Really fills in the vocals.

 

Where things get interesting - I also use the time delay rear channels from my C4000 pre to fill in the room and really make the music pop. Secret is balance as you might expect. The C4000 drives four book shelf speakers using a Dynaco Quadaptor. One pair is mounted at ear level directly to the sides of the main chair, and the other pair at ceiling height behind the chair.

 

- Turn on the rear speakers only, and adjust the balance top to bottom using the Quadaptor. This gives me "height" as well as allowing me to adjust the time delay reflections to my liking.

 

- Step two - bring up the volume on the center channel located at ear height in front. This effectively pulls the rear channels forward and pops the vocals.

 

- Final step - bring up the front big box speakers to taste. I'm actually using two holographic generators in the system - the one built into the C4000 is set to wide, and the H9AV drives the front boxes only - that's just got the standard holography engaged. All in all, an audio purist's nightmare, but I like it!

 

 

 

[kve777 6,897]

If your main speakers are more than 10' apart, a center will fill in the middle. If you have a small room, speakers 6'-8' apart, no need. 

[sKiZo 186]

Not necessarily true, at least here anyway.

 

My main speakers are around 7 feet apart, and you definitely notice if the center is switched out. It's not all about filling in the middle ... it's more instrument placement and focusing the primary vocals center stage for me. Especially important for near field like my room.

 

Current setup (WITH the center active) SEEMS reliably accurate for instrument placement, at least with stuff I've seen live. I say SEEMS because a lot of those performances happened quite some time ago, and that ... er ... brain thingy that lets you ... uh ... Oh, I remember ... memory! ... ain't what it used to be.

 

PS - as with most of this stuff, moderation is key. My rule of thumb, if I don't notice an effect until I turn it off, time to at leasat turn it down. The H9AV's L+R output that I use on the center is direct out, but fortunately I can adjust tone and volume on the Eico HF12 mono amp driving that channel. I'm also finding out all center channels are not created equal. I really like the output from the H9AV, but I wonder what sort of fun Mr Carver had with that - all sorts of surprises lurk within sometimes.

[kve777 6,897]

I think the effect you are experiencing is akin to a HiFi mono set up. Before 1958, we just had HiFi. One amp, one speaker. With a good mono recording and a high end reproduction set up, you can get a pleasant sense of placement and focus. It's really quite startling. I've done it a few times. My feeling is that your center is actually narrowing the sound field, opposite effect of Sonic Holography. Look, every system and room have their own signature. Some effects that are liked by some are disliked by others. There are always exceptions. By all means experiment with any and everything you can get your hands on. If you enjoy it, it's not wrong.