Car Stereo Experts-Help Needed!

Rot 911 · 09-03-2003, 05:47 AM

About 2 years ago I installed a Blaupunkt Alaska CD/receiver in my '86 Carrera along with Infinity Kappa Speakers. The receiver is 40 watts per channel and the speakers can handle 100 watts. No additional amplifier. Worked just fine. However, in the last few weeks if I turn the volume up more than 2/3 after about 10 minutes the right front speaker will cut out. The other 3 speakers continue to work just fine. I can turn off the receiver wait about 5 minutes turn it back on and the speaker will work again. If I turn the volume back up the speaker will cut out again. At low volumes there is no problem. I checked all the connections and they are good. Haven't switched out the speaker yet thinking this is a receiver problem. Am I just overloading the receiver by running the volume too high? Should I get a more powerful receiver or will adding an amplifier solve the problem? TIA!

dotorg · 09-03-2003, 05:49 AM

Perhaps the speakers have clipping protection? Power doesn't blow speakers, lack of it does. No head unit really does 40w per channel, certainly not cleanly. Its possible that you just don't have the power for the volume you want and the speaker is protecting itself?

Generally if you're going aftermarket with radios, an amp (even a cheap low-power one) is a good idea. A 40wpc amp is significantly different from a "40wpc" headunit. You'll hear the difference, and your speakers will last longer.

makaio · 09-03-2003, 05:51 AM

Kurt, it sounds like a reciever problem to me. If you add a amp it will lower the work load on the rest of the components. That's my .02 cents, I'm sure Bell could explain it the best.

RickM · RickM's Garage

I'd also say it's the receiver. Most likely heat related. The louder you crank it the hotter the output ICs get. Either it's supposed to shutdown at the level you have it at or it's happening prematurely.

If you open the unit (probably not worth the effort nowadays) you'd spray component cooler on the suspect IC upon failure....it would most likely come to life until it heats up again. After you identify the culprit you replace.

However, it sounds like you may be asking for more than your equipment can handle. An aux amp may be your best route.

911SC Pilot · 09-03-2003, 07:37 AM

Its your Blaupunkt I think. Mine does the same thing with my passenger door speaker. I have to tap the volume control when the speaker starts to go out.

bell · bell's Garage

sounds like the 2 years of having limited power going to your speaker has burned the voicecoil, what happens is when a speaker is in need of more power than available then the supplying amplifier (in your case the radio) overworks and sends a clipped signal to the speaker (distortion basically) this distortion is usually associated with dc voltage which creates excess heat and burns the voicecoil.
your's is heating up to the point where once it gets to temp the voicecoil is losing contact internally.......
i would replace the speakers with either a more efficiant speaker (less power) or add an amplifier

scottb · 09-03-2003, 03:42 PM

Kurt: FWIW, I have a pair of MB Quart speakers in my doors, powered by a Blaupunkt Heidelberg, and they sound great. They weren't terribly expensive, either.

Good luck.

Scott

Jared at Pelican Parts · 09-03-2003, 03:55 PM

Sounds like you need to add an amplifier in between the head unit and the speakers.

david914 · 09-03-2003, 06:12 PM

Cast my vote for a problem with your head unit. To find out for sure, swap the front outputs coming out of the head unit. Connect the left output to the right speaker and vice versa. If your problem stays on the right, your problem is in your speaker or associated wiring or crossover. If the problem moves to the left, you have a head unit that's going bye-bye.

Eric Coffey · 12:34 AM

David makes a good suggestion. If the problem changes to the L side by switching inputs, then it is obviously a receiver (internal amp) problem. Also, you mention that the "other 3 speakers continue to work just fine". If so, they might be on the same (parallel) circuit, causing the internal amp to overheat/shutdown due to low impedance. Anything below 4 ohms per channel is (generally) too much for a standard internally amplified car receiver to handle. Either way, an external amplifier is always better than the misrepresented internal power of most receivers. They can get away with listing your head unit as "40 watts per channel" due to the fact that it is 40w at 10-30% THD!

Rot 911 · 09-04-2003, 05:06 AM

Thanks for all the help guys. I installed a 400 watt, 4 channel amp and the problem is solved!

trj911 · trj911's Garage

I would blame it on the receiver also. 4 years ago I bought a Blaupunkt Honolulu (25w x4) with Infinity speakers and about 1 month ago the left front started cutting out. I rewired all the speakers and still had the same problem. I traced the problem to the wiring harness where it plugs into the radio. The connectors on the back of the radio had come loose and I could not fix it even with a new wiring harness. I replaced the radio with a Pioneer DEHP5500MP (50w x4) for about the same cost as the Blaupunkt and everything is perfect.

What kind of amp did you install and where did you put it?