HELP! WM/TW center does not like my TV!

[digital desire]

So, I get it all together, but when I turn it up, it screws up the picture big time, to the dynamic of the music. You can see how I set it up on the tv in the pic. The crossover is mounted on the back wall of the cabinet.
Will taking the crossover out, and mounting it somewhere remote cure this?
It was bad enough trying to sell this to my wife, this wont help! ops:
EDIT: Just tried a cookie sheet under the cabinet, no joy.

[---k---]

Get a DLP?

I was going to suggest the cookie sheet, but it sounds like you tried that. I'm a little suprised that didn't work better. It wasn't aluminium by chance? I experimented with 16ga steel roof flashing steel (like $15/roll at HD) and a big RL-p15 subwoofer driver. The steel appeared to make a big differance.

[wkhanna]

Get a DLP?

It wasn't aluminium by chance?

That would make all the difference.

[digital desire]

LOL, no not aluminum, it is actually a iron cup cake thingy.
At least I *think* it's iron. It is coated, but feels fairly heavy..
Also, here is a pic of the crossover. Would the steel laminate be the guilty party?
Speakers themselves don't send out magnetic fields other than their respective magnets do they? In other words, is the voice coil a big radiator in this area? Or is the magnetism they generate contained within the speaker?

[kgveteran]

OMG! That friggin' thing is huge.I think we need a plan "B".

OK, how about a stand that goes on either side of the TV rather than on the top.This will give you a chance to get some room under the center and maybe try some sheet metal. I really don't like the looks of that monster sitting on the back of your monitor.I think I'll give Adam a call and see what we can cook up.

[Dennis H]

Just to make sure it's a magnetic problem rather than a mechanical one, try supporting the speaker somehow so it's not touching the TV. Some CRTs don't like vibration. I have my tiny shielded computer speakers sitting on top of my Trinitron monitor and certain tones, even if not very loud, as well as loud music in general, can drive it nuts.

[cjd]

Um. That pan sure looks like it may be aluminum to me. If it's steel, it's not much of it...

C

[JonMarsh]

well, if the crossover is on the BOTTOM of a horizontally SYMMETRICAL speaker, then I would suggest, at the least, moving it to the TOP by rotating the cabinet 180 degrees. Speaker magnets and crossover components that close to a CRT is just asking for trouble major league...

That cup tin is probably steel, but there's not nearly enough of it.

[Hdale85]

Get your self a lat christmas present :B A nice 720p front projector....or a DLP/LCD RPTV like previously mentioned Other then that good luck.... Thats a monster of a speaker to sit on top of that tv though.

[Brian Bunge]

Jon,

Rotating the center could actually make things worse since that would put the unshielded tweeter even closer to the CRT.

[digital desire]

I would love to get a sony 50" wxrd rear projection, but the speakers have pretty much killed that budget. This center has to weigh close to 80lbs! So unless I suspend it from the ceiling (my Wife would serve me papers!) I dont see how I could even begin to come up with a mouinting solution on it.
I think KG has the right idea. I see some 3/4 inch oak plywood in my future...
It is a damn big speaker~!
The crossover is mounted on the back of the cabinet.
I really dont think it is a vibration issue, but will try to find a way to see if it is.
So, if it is not, will remote mounting the crossover, maybe using the 8 conductor cable and 8 pole speakeon connectors from PE solve the problem?
Can the speakers themselves be generating the field, even though they are shielded?

[digital desire]

And yes, that tweeter is *just* out of range for the crt to give it trouble. At 8 inches away, it starts to change the image, in the cabinet it is 9" away, which is just enough.

Edit: To test the vibration theory, I am going to put it up on its end, and crank it up. I have to wait until Wednesday because the family would just not understand... 8)

[digital desire]

Just weighed it.
76lbs!

[Brian Bunge]

Mine's probably slightly heavier than that then. It's an inch shorter, thanks to my screwing up one of the dimensions. But it's also 2" wider, several inches deeper, has 1.5" thick front and back panels, and heavier bracing. It's also got a more complex crossover with several 15 gauge inductors.

[---k---]

THAT IS NOT A COOKIE SHEET! :P

I think if you go to HD or Lowes and buy a roll of steel roof flashing, and contact cement a piece to the underside and top side of your little stand, it would go a long way. If it doesn't completely eliminate the problem, you could add additional layers until the problem is solved.

The flashing is only like $15. So you don't have much to loose in trying.

Also, distance is your biggest friend. Does lifting the speaker up another 2" make a difference? I'm guessing it does. Try using distance and steel, and you should be there. (Add some spikes under the speakers to make it look cool on the stand.)

And finally, one thing that has been mentioned here in the past is that the individual TV makes a big difference. Some CRT TVs have more shielding in them than others. I think my old Toshiba was pretty tolerant of speaker magnets, but a Sharp that I had before that wasn't. So, it is really hard for people here to give specific distances etc. and guarantee that they work.

Good luck.

[kgveteran]

Get that stand started and try the contact cement to stick it on.It seems to be your only option.There is room just behind the front gray portion of the monitor.And the back is wide open.You can get it two inches above the monitor and angled down to the listening position.

Unless a big bag of money fall off a truck in front of your house.

KG

[digital desire]

Got Lucky.

It was the crossover. I was lucky in that I used a bi-amp terminal cup when I put this together. That of course has four binding posts on it, allowing me to remove the crossover, and run four wires up to and into the cabinet. The crossover is currently on the floor awaiting some sort of box to enclose it.

I cranked it LOUD, and not a single shake in the image. YES!

But that brings me to my next question. During my "testing", I smelled some hot melt glue melting. I then burned my finger on the 15 ohm resistor in this crossover.

http://www.htguide.com/forum/showpost.php4?p=289904&postcount=1388

net 2, the midrange. The schematic shows a 17 ohm and the BOM shows a 15 ohm from madisound. I think it is a 5 watt, it looks like the more common type of resistor, not the ceramic square ones that are used everywhere else. I do recall DM saying the 15 ohm one was fine, but maybe it should be a couple of 30 ohm 10 watters? That bad boy be hot!

Anyway, Normal? Sounds Great! But the tip of my finger is now burned....

[JonMarsh]

I would use your idea of 30 ohm 10 watters in parallel. Anthing getting hot means the value may drift a bit, too- resistors have temperature coefficients. I mean, how loud were you playing it, with what kind of program material? To melt hot glue?

[digital desire]

I like the concert DVD's.
So it has to sound like a concert. Clapton, Pulse, Zepp, etc.
Really, the main reason I went with a huge matching center to the towers. (Which have yet to be built)
I will slip in a pair of 30 ohm 10 watters now that the crossover is so naked.