Fitted active sub...

[JiMR2]

Hey all,

Fitted my Blaupunkt 200a active sub in the rear bins today - following Stargazers guide (Thanks mate!  s:) s:) ) and it all has gone in a treat! Loks and sounds the nuts...

However, after intially testing and going for a spin (when it sounded perfect), i have just discovered that when i turned the car over it emmits a high pitched whinning sound!!!   s:scared: :scared: s:scared:  

When i drive, the whinning increases/decrease in pitch with the increase/decrease of the motor!?!?!?!?   s:crazyeyes: :crazyeyes: s:crazyeyes:  

I have run the RCA's down the passenger side trims, under the carpet and into the back of the HU - as described on the guides on here for installing amps so am unsure where/what i have done wrong?!   s:cry: :cry: s:cry:  

Any help or advice would be greatly appreciated - as always!!!

Thanks guys,

Jim

[markiii]

where did you ground its power supply to?

[JiMR2]

Hi Markii,

I grounded it off on the Ground battery terminal

[markiii]

that should be ok

does it still do it without the rcas connected?

[JiMR2]

When the RCAs are disconnected = no strange whinning... ?

Just noticed that when i turn the lights on i get a click come through from the sub...

As the battery terminal is a Negative, does it still class as being a Ground? Am just wondering if the fact that its hooked upto the battery ground being the problem??

[markiii]

your ground should be ok, I ran that way with no issues

if it doesn 't do it with the rca disconnected you have induced noise (probably alternator related) on your signal wires

to double check disconnect the RCA at the head unit

if it persists some ferite rings on the signal wires may help

if it disapears then your hu and amp are at different grounds relative to each other, in which case try grounding them to the same point

[JiMR2]

Thanks for the responses Markii - much appreciated!

signal wires

- sorry for being uberly noobified but/where may i find these?

As per grounding the amp/hu at the same place - the HU i just hooked up to the ISO block so i imagine it to be grounded on the chassis - is it worth trying it grounded off on the chassis prior to checking out the other bits?

[markiii]

by signal wires I meant the RCA

whilst in practice you can 99% of teh time get away with grounding different equipment to different places, in tehory you should always groud to teh same point as different resistances/condition of ground connections, e.t.c can mean that the ground references are not exactly equal, which can cause your symptoms

[stargazer30]

Jim,

Mine did this also when i had my Pioneer double DIN unit but it was very subtle, not that noticable at all.  I haven't noticed it since I swapped the HU for the cheaper kenwood unit I use now, but will check once I get the car back off Nicola (tuesday   s:shock: :shock: s:shock:  )

It is noise on the RCAs, I have a feeling the units ability to remote power using the RCA instead of a dedicated remote feed may have something to do with it.

One thing you can try to eliminate it is turn the amp down on the sub and turn the sub output DB up on the headunit so you get the same volume but hopefully less noise.

David

[JiMR2]

Thanks for all the responses and advice guys!   s:D s:D  

Got a few things to try from the above so will update when I find the one that resolves the issue in case future memberes get this issue!

Thanks again!  s:) s:)

[stargazer30]

Ironicallly enough and reluctantly! I've just taken my active sub out the 2.  I've finally given up trying to get my fronts (focal A1s) to sound decent off the amp in my HU and realised I'm going to need to amp them.  I figured If I'm putting an amp in I may as well get a 4 ch and use it to feed the sub too and avoid power splitters and line out splitters and all that hassle.  So I'm now building a very descrete 8" sub box thats fits in the driver side bin to replace the active sub for when the new amp goes in.  Better still would be one of those under dash sub boxes but they are not easy to get ahold of.

[Thudd]

I got this from my iTrip, powered from the cigar lighter. I binned it in the end, as it drove me mad.

[JiMR2]

Just an quick update, incase others come across this...

Have tried moving the ground wire from the Battery negative onto the chassis and the made no difference at all - frustratingly... The whines still there...

So have now purchased some ferrite rings that look like clamp connectors to be honest... will pop off the kickpanels and fit in the week (whilst making panel templates) and report back...

Cheers

[JiMR2]

Finally fitted the ferrite rings today... unfortunately they've made no difference at all... learnt to live with the noise now though to be honest... just turn the music up louder!  s;) s;)  Just thought i'd note it down for any one who may come across this post in the future via search...

[Hogzi]

Isn't this just an issue with the alternator??  When I used to fit stereos (many years ago) this used to be a usual issue and fitting a suppressor to the alternator should sort the issue out...... I could be completely wrong though but it might be worth looking into??

[cclarke99]

Definitely agree this is a problem with the Alternator, the whining noise changing with engine speed is a common symptom. It might be worth trying a suppressor connected between the alternator output and case, although they're generally meant to fix radio interference at a higher frequency. I wouldn't expect the ferrite rings to help much as the interference you're seeing is at a relatively low frequency. You may have some sort of earth loop as suggested above or it may be that the wiring is close to some other wiring carrying a high current - the supply for the power steering for example. To avoid an earth loop, the HU and the amplifier should be wired to the same earth point (again as suggested above). Excuse my ignorance but what are the RCAs?

[s12vea]

Make sure your using the power and earth cable of the same size (gauge).
When possible make the earth cable nice and short and direct to chassis.
Have you got the amp gain turned to maximum? Try turn it down a bit and use the headunit volume control more.
Double check the rca / speaker wires arent crossing the power cable.

[JoniiBoii]

Would this work ?

As I'm having the same dilemma and is really annoying when I don't want the music it up at high volume !

 m http://www.halfords.com/webapp/wcs/stor ... &langId=-1 m

And how the hell do you fit it? Lol

[stargazer30]

My advice would be ebay the active sub and replace it with a 4ch amp and a traditional sub.  Those active subs are decent for adding bass fill at low/medium volumes but no good for loud stuff.  I recently fitted a UD sub and its the best bass I've had yet out of an MR2 and I've tried lots of different subs and installs.

[JoniiBoii]

Unfortunately I forgot to add the whining noise is due to my focal components which I've amped unfortunately they still whine like a gooden , can't seem to find out the problem so will the above link work do you think?

[stargazer30]

Unfortunately I forgot to add the whining noise is due to my focal components which I've amped unfortunately they still whine like a gooden , can't seem to find out the problem so will the above link work do you think?

No the whining noise is alternator whine, its noise in the input to the amp, nothing to do with your focals.  First I'd check/replace your RCA leads between the HU and AMP, a bad earth on any of the connections will cause it.  Other options that might work would be a different Amp.  My JBL amp gets no whine but my active blaupunkt sub used to.  Not sure but a ground loop isolator may help.  If you are using an Amp and sub combo you can use the LPF on the amp to get shot off if going to the sub but that won't help the focals, you really need to get rid of it at source.

[Zoe]

Im not an audio buff but my other half is so il get him to have a read of this for you

I had the same issue in my old car, it can be down to interference with other wiring. We fitted an in-line RCA interference suppressor and sorted it out.