Klh av5001 tower 350watt speaker at bottom has no magnet nor any connections for it.looks like a fake speaker why

That is sometimes called a "radiator". It's a speaker cone that moves opposite the main woofer and produces sound waves out of sync with the powered woofer. Very sophisticated piece of audio engineering intended to enhance bass response.

Without knowing what they're hooked up too.. SOUNDS like your uder powering them, OR over powering them. Look at the back of the speakers the wattage is what your looking for, look at your amp, example: 1000w speaker running on 50w amp = not good.

I would check the caps on the power supply. They are rather large electrolytic capacitors that will look like they burst and/or leaking. When these die, the caps ground and the sub will make a loud buzzing sound. If you are handy with a soldering iron you can replace them yourself. Replace them with the same voltage or a little bigger and same with the size.

If the cap. says 16v 4700pF on it, for example, a 20v 5300pF or a 16v 6200mF cap. will work for this application.

http://worldwide.bose.com/productsupport/en_us/web/article_232_connecting_to_a_computer/page.html
http://www.ehow.com/how_4914167_connect-speakers-laptop.html

Yes, probably, if you aren't capable of repair yourself. However, IMHO, a replacement will probably cost less in the long run. I have a KLH passive subwoofer myself. I wouldn't pay for any repair if it failed. Replacements are far too inexpensive.

Hello
Check the impedence of the connected speakers. if any impedence mismatch is there, the amp will sense it and will cuto the output OFF. Use only specified speakers only. The impedence of speakres are expressed in "Ohms". Select all speakers of same impedence. If 6 Ohms is the output impedence of the amp, use only that Ohms speaker. Never use a speaker less that this Ohms. You can use a higher impedence speaker, say 8 Ohs or 16Ohms. But never use lower impedence speakers, of connect two speakers in parellel connection, which will relult in overloading. I think that I've made a satisfactory solution to you. Please don't hesitate to rate this solution. Good luck
Wish you a Merry X'mas and Happy 2012.
Gopakumarg43

You're playing with fire if you insist on overdriving them. Something will eventually blow up permanently.

Overdriven amps will distort and distortion will hopefully make the amp self-protect before it kills the speakers.

Generally speaking, an amp attempts to protect itself from heat, shorts, overloads and operator exuberance by refusing to turn on or stay on; or it may turn on but produce no audio to the speakers.

Overloads can be from excessive periods of high output or marginally low impedance loading by the speakers; and shorts would be wiring issues or a speaker blowing up.

You should be able to feel if it's hot. WHY is it overheating? Make sure it has sufficient ventilation on all sides and that vent holes are not blocked by dust balls. Ensure the fan (if equipped) is running as designed (some only operate on demand). Clean dust and debris from it.

If the amp comes back on after cooling, you're lucky. They only have so many self-protection cycles in their lives so continuously resetting or cycling their power without addressing the cause can do more harm than good.

If it protects immediately on a cool power up you should disconnect the speaker connections and try it 'nekkid'. If it comes up then diagnose which lead(s) are shorted. If it does not come up the problem is internal and should be left to an experienced and competent hands-on tech.

Try the KLH site. I have downloaded (for free) info on KLH products. Not much on technical stuff, but set up info and connections.

Well to get the full effect of 5.1 surround you will need 2 front speakers, 1 subwoofer, and 2 rear speakers. Personally I used 2 tower speakers, 2 rear speakers and a subwoofer. Match the speakers with the RMS wattage of your Receiver. (100x5) or roughly 50 watts per speaker. Yamaha, KLH, Philips are pretty good speakers.

Try pushing the speaker button under the power button on the front.