Tonight I re-installed my Kenwood amp and hooked it up to the Pioneer shallow sub and when playing fairly loudly the sub 'pops' and shuts off, then resumes playing only to pop and shut off again. This isn't cancellation is it?

I've been running that sub off my Boston amp for ages now with no dramas so it must be something to do with the Kenwood amp. Is the sub getting too much power? Thinking back I realise this has always happened with this sub-amp combination.

I'm getting a new amp to drive my Boston sub which has been waiting patiently to be used and I want to sell the Pioneer and Kenwood but want to make sure there's nothing wrong with anything before I do. (By the way I would sell them in the Quakka as I always do)

Any comments appreciated


Doug

what amp?
maybe you're not feeding enough current to the amp?
or maybe just over-driving it (sounds like it going into protection for some reason)

The amps going into protection

possible causes
1) blown sub
2) bad power/ground wiring. Either a bad ground, a loose terminal, incorrect power wire sizing, or a partially blown fuse. What size power/ground wire are you using?
3) speaker cables shorting out

You know I actually went and looked at the box when I posted the question to see what the model number was and didn't put it in! (Kenwood KAC 7252 just for the record)

Bingo!

You won't beleive this, It's hard for me to comprehend myself
I have NOT connected the ground wire at all! It's a wonder it even works! By the way I didn't have to go out to the vehicle to check it, I just know.

Conclusion

I need more sleep

Thanks for the replies


Doug

oooohh thats bad...you may want to make sure that the internals of the amp, and hu havnt fried...by not connecting the amps ground, it will try to ground thru the rcas, into the hu, killing it....

Right thanks for that

Yeah as soon as I noticed it (after about 5 minutes) I turned the sub off but didn't disconnect the power to the amp until tonight.

Sooo... watch out for a dodgy CDA9847 on the trading post!

cheers


Doug

If you get system noise/alternator whine when you do ground it, I can bet i know what your problem will be

Also, was the amp screwed down to bare metal? sometimes they like to ground through the amp chassis. BAD. You should mount the amp to mdf, then the mdf to metal, if all else fails.

Thanks for the reply

It's not screwed to bare metal but the cargo barrier is between the amp and the board. It quite well be earthing through the chassis.

So what does the alternator whine come from?


Doug

A cars electrical system is very noisy. Alternators, regulators, ecu's, etc etc.

When your grounding system goes caput, it becomes very easy for this noise to enter and corrupt the signal path. Hence, you get a high pitched whine, which usually increases with revs.

Sounds like a poor mans turbo, through the speakers

I've often had alternator whine over the years with different cars but I thought you were going to say something is stuffed. Anyway the whine is gone now.

Interesting you know, all the time the Kenwood has been absent I haven't had it. Then as soon as it's re-installed the whine returns, then takes a while to dissappear after the Kenwood is gone again. If I can't afford that GT-28 I'll have to do something about it.

cheers