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Speakers pop on start-up

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=40027
Printed Date: May 02, 2024 at 10:53 AM


Topic: Speakers pop on start-up

Posted By: EluminusSVT
Subject: Speakers pop on start-up
Date Posted: September 29, 2004 at 9:43 PM

Hey everyone, I have a problem that you guys will probably solve in a second. I have a 1995 Mustang SVT Cobra (https://members.cardomain.com/eluminussvt) that I just installed an aftermarket receiver on. As you guys know, my Cobra came with a Mach 460 Sound System which turned out to be a pain in the ass when it came to swapping out parts. Anyways, I had to buy the normal wiring harness and also a line output converter (which had it's own ground coming out of it) for all the speakers lines. After about an hour of installing, I finally got it done. My problem is this; when I start the car, all my speakers "pop" and also, I have no sound in my front left side (door and A-pillar mounted tweeter).

Can someone help me? Please try and IM me if you have AOL, I would really love to get this done so I can have my system back. Thanks!




Replies:

Posted By: Velocity Motors
Date Posted: September 29, 2004 at 9:53 PM

Are you powering up the Mach amplifier's with the aftermarket deck remote turn on lead ? Here's some information about the turn on/off pop:

This kind of problem is often caused by transients in the signal processor as it powers down finding their way into the signal path, which the amplifier then transmits to the speakers.

Usually this can be solved by adding a little turn-off delay to the processor. This allows the processor to stay powered on for a short time after the amplifiers have powered down, thus preventing the pop.

Many components sold today (such as crossovers, equalizers, etc) have delays built-in. Read your manual to see if it is possible to set this delay on your piece of equipment or be sure to look for this feature during your next car audio purchase.

If your processor does not have this feature, you can build your own delay circuit with a diode and a capacitor. Add a 1N4004 diode in series with the processor's turn-on lead, striped side towards the EQ. Then add a capacitor in parallel, the (+) side of the cap connects to the striped (processor) side of the diode, the (-) side of the cap goes to ground (not the radio or EQ chassis - connect to the car chassis).

Experimenting with the cap value will give you the right amount of delay before the EQ shuts off. You don't want it too long, just long enough to make sure the amp is off before the EQ powers down. 220 - 1000 uF is about right, and make sure the cap is a polarized electrolytic, 16V or higher. Also keep in mind that the diode will introduce a 0.7V drop on the remote wire, which can cause the processor to power down before the rest of the system.

With the fans, I would wire then along with the remote turn on lead of the system so there is continuous cooling for the amplifiers.



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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA




Posted By: EluminusSVT
Date Posted: September 29, 2004 at 9:59 PM

Yes, I am powering the two stock amplifiers with the deck's remote turn-on lead. I will try looking into the what I thjink is the crossover that I bought. I have to admit, that reply was a lot to swallow.

Thank you very much for you're help.





Posted By: Velocity Motors
Date Posted: September 29, 2004 at 10:03 PM
No problemo, I think posted_image

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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA




Posted By: EluminusSVT
Date Posted: September 29, 2004 at 10:14 PM

Ok, I'm reading this over like a million times to make sure I have it right. Is there anything else that could be the problem before I go ripping into this mess.

And what about my front left door and tweeter that don't have sound?

Thank you again for your help.





Posted By: heavilymedicate
Date Posted: September 29, 2004 at 10:29 PM
Yeah, Velocity Motors is very knowledgeable, but sometimes his suggestions are scary-hard to swallow.  I really do not have anything to add except...  Keep it stock, the car's exterior that is.  I saw your poll on sounddomain.  I can’t stand tacky, gawky cars and yours already looks pretty sweet.  Mod that audio system though!  Simply put, stock sucks and Mach is no exception.




Posted By: heavilymedicate
Date Posted: September 29, 2004 at 10:41 PM

The door problem is easy to test.  Pull the deck and swap the sides on the line out converter.  If your sound (or lack of sound) switches from left to right when you change your converter, you have a wiring problem from the converter back to the deck.  If you do not then it is from the converter forward.  Start there.





Posted By: EluminusSVT
Date Posted: September 29, 2004 at 11:14 PM

Ok, I found pictures of what I'm working with so yuou can maybe what my problem is.

Here's the low-level interface - Scosche Industries Products >> Scosche

Here's the harness (the one's being used, per manual, are the one all the way to the left and all the way to the right) - Scosche Industries Products >> Scosche

The wires coming out of the receiver are put into the "input" (duh) side of the interface. The "output" side of the interface is then being connected to the harness which will be plugged into the factory harness. The guy at tech support told me to take the "Amp Lead +" from the Scosche harness and connect itt with the power wire that was going into the power wire back to the receiver. Maybe this will help. Thanks!





Posted By: EluminusSVT
Date Posted: September 29, 2004 at 11:54 PM

I've been reading back on the ever popular "popping" sound on start-up. It doesn't make a pop during music. Only a small pop on accesory swtich and then a louder pop when the car is started.

Someone said this is becuase of a bad ground from the harness. Comments? Ideas? Thanks!





Posted By: djmoose
Date Posted: September 30, 2004 at 11:44 PM

Wait a second...wait a second

What are in inputs on your Mach amplifiers? Speaker level or line level? From the ones I see on Ebay, it appears to utilize the typical "diffucult to work with" factory pre-outs.

Secondly, why do you need a line output converter if you already have an aftermarket deck? (unless you replaced the factory radio with a deck that didin't have RCA outs...which would be kinda pointless...

Also, if the Mach 460 amps need a speaker level input...just use the regular speaker leads on your deck!





Posted By: rknj01
Date Posted: October 01, 2004 at 12:25 AM
put some resistors on the remote turn on lead. ive had the problem with tons of mustangs. i thinks its because the stock turn on lead is less than 12v.




Posted By: stevdart
Date Posted: October 01, 2004 at 10:41 AM
...or you could try a low voltage trigger device like this Peripheral LVT on the turn-on lead.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.





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