Some dumb speaker quesitons...plaese help!

[jdchess]

My first question is about my center channel speaker. I've noticed that several of the center speakers that I have looked at still cause some color shift and distortion if placed on top of the TV (CRT) itself...even though they are "supposedly" shielded, so...

1. Are there actually center speakers that cause no distortion or damage at all to the CRT or do most cause at least some if placed directly on the TV?

2. How far away from the TV does a speaker really need to be not to cause any distortion and/or CRT damage?

3. What would be my best option for center speaker placement if I cannot put it directly on top of the TV?


Also, I have another question about DVD storage. This may be a dumb question, but I'm curious. Is there any problem with placing a DVD rack directly next to my large main speakers or directly next to the CRT? Can the magnetic field cause any damage to the DVD's? Thanks in advance for help guys!!

 

[MDS]

Magnetic shielding is no guarantee that the speaker won't cause distortion in a CRT TV but usually does work. You'll have to experiment with placement to eliminate distortion but a foot or so away is usually sufficient.

If you have the TV in a wall unit type cabinet, you could put the speaker on a shelf above or below the TV or you could place a shelf on the wall above the TV if it is not in a cabinet. You can also try placing it below the TV angled up towards the listening position.

CDs/DVDs have no magnetic fields on them so placing the DVD rack next to the speakers will cause no damage.

 

[JKL1960]

I've previously placed my Klipsch RC25 directly on top of a 30" Toshiba CRT and below it with no noticable effects at all. It sounded better on top but looked silly.

Currently I have a Paradigm Cinema CC sitting on top of the same TV and the bookshelf mains right next to it with no noticable effects. So yes there are speakers shielded well enough for this.

(Note to self - need stands for mains for better sound stage.)

 

[jdchess]

Thanks for the response guys. I have an additional question about the center speaker placement. I was thinking that a shelf on the wall above the TV might work. My CRT is on a stand and not in a cabinet. What I'm wondering about is this:

The TV and the main speakers are about 2 or so feet from the wall. Placing the center speaker on a shelf above the TV would place it closer to the wall. Would this create any problems at all (the center speaker not being in line with the mains and closer to the wall)? Thanks again.

Jason

 

[MDS]

It creates minor problems but nothing to really worry about. You may find when you do the receiver calibration that you'll have to bump up the center channel level a bit higher than the mains to get the SPL equal to the mains.

I like to use PLII Music mode for pretty much everything. It has user adjustable parameters - Panorama, Dimension, and Center Width. The Dimension setting allows you to move the soundfield forward or backwards. Using PLII Music mode and adjusting the Dimension parameter will compensate for the fact that the center is slightly behind the mains.

 

[JKL1960]

Thanks for the response guys. I have an additional question about the center speaker placement. I was thinking that a shelf on the wall above the TV might work. My CRT is on a stand and not in a cabinet. What I'm wondering about is this:

The TV and the main speakers are about 2 or so feet from the wall. Placing the center speaker on a shelf above the TV would place it closer to the wall. Would this create any problems at all (the center speaker not being in line with the mains and closer to the wall)? Thanks again.

Jason

In theory it might but in reality I don't think you'll notice. I've been playing around with center channel placement a lot lately and have not noticed a difference moving it from in line with the mains to about a foot behind. Even without readjusted speaker distances in the amp. I'd be surprised if it made a huge difference.

I'm becoming convinced that having the center channel moved slightly to one side works better than having it exactly centered. It seems more transparent when slightly off center.

 

[jdchess]

Thanks for the response guys. Aside from being out of line with the mains, how far ABOVE the mains is too high for the center channel? Have either of you played around with the height of the center at all? Since I plan to build a wall shelf for the center, I want to make sure it's far enough above the TV that the speaker will not harm the CRT, but not so high that it distorts the sound because the center is too high above the mains. How far from the TV should a speaker be as to not harm a CRT (assuming no shielding at all)? Thanks again.


Also, JKL1960 could you explain a little more what you meant about it possibly helping the sound by placing the center speaker off-center? Thanks.

 

[JKL1960]

Also, JKL1960 could you explain a little more what you meant about it possibly helping the sound by placing the center speaker off-center? Thanks.

Sure thing.

It is instinctive to place the center channel exactly centered between left and right. Now, I read somewhere, possibly on this site, that moving the center speaker slightly off center makes it more transparent. When I had it exactly centered I noticed that some dialogue sounded as if it were coming from the speaker instead of the image on the screen. Particularly when a character was at the side, not centered, on the image. Moving it slightly to one side, I think I am about the width of the speaker off center, seems to put the dialogue back on the screen. I have a 106" screen which may make the situation worse than a smaller TV screen.

Of course, beware of placebo effect. We are often easily fooled.

 

[jdchess]

Thanks again for all the response guys. So you all think I would be OK placing the center speaker on a wall shelf directly above the TV even though it would be 1 to 1-1/2 feet behind the TV and the mains?

 

[Tomorrow]

You should attempt to keep the fronts and center in a line. Time alignment and off-axis performance are just a couple of potential issues with moving these three speakers around willy-nilly.

By the way, a good rule of thumb is that an unshielded speaker should have no impact on the tv if each driver in the speaker is at least 1.5 times its diameter from the tv. Ex: A edge of a driver from a front main (unshielded) speaker with a 12" diameter should be at least 18" from the edge of the television. A 6" driver requires a 9" separation, edge to edge. Etc.