Upgraded speakers, now have a crackling sound from rear speaker.

[ViperJohn]

I went ahead and upgraded the stock speakers in my 02. I installed two polk DB525's in the doors and put a DB650 for the rear sub. For the initial installation I bought spade connectors and hooked up the speakers. The system sounded great. Of course all testing was done while the car was parked.

When I went for a cruise I noticed some mild popping and crackling noise from the speakers. When the engine is turned off, it goes away. I decided that perhaps the spade connectors are not making good enough contact so I went ahead and soldered the wires to the speakers.

After another drive, still experiencing the crackling and popping sounds. An under hood inspection revealed a disconnected ground at one of the cowl mounting supports. At this point I thought I had it figured out. However after another drive tonight the crackling and popping is still there.

After playing with the bass, treble and fader it appears most of the crackling/popping is coming from the rear speaker. I have checked the amp and plan on removing all the speakers and re-checking my soldered connections.

I then had an epiphany, could the MSD wires on the engine be causing speaker interference? I remembered reading that the MSD wires can cause problems with the radio reception, but has anyone had a problem with speaker interference?

The only other pertinent information I can think to add is:

• Stock Amp
• Stock Head Unit
• Factory wires
• High lift cam w/ported heads (mentioned due to added engine oscillation)

Getting ready to drive to VOI soon, so I would love to have this rectified before then. Any help, pointers or similar experiences welcome.

Thanks in advance.

 

[mjorgensen Woodhouse]

Are you sure the Polk's are compatible with the stock amp? When you are driving is the volume at the exact same level as parked? The ohms could be different for even the factory speakers front and rear along with the alloted wattage for front and back.

FWIW

 

[ViperJohn]

Are you sure the Polk's are compatible with the stock amp? When you are driving is the volume at the exact same level as parked? The ohms could be different for even the factory speakers front and rear along with the alloted wattage for front and back.

FWIW

Same volume settings when parked/driving. I am sure the Polk's have a lower ohms rating than the factory speakers, but my understanding is that would allow the speakers to be louder at the same volume setting than stock due to their lower resistance. Also, do you think an ohm difference would explain why this is only happening when the car is being driven? The speakers sound phenominal when the car is parked with the engine off. Thanks for the input.

 

[mjorgensen Woodhouse]

Lower ohm speakers are more difficult to drive than the factory ones, this is why the receivers and amps are rated into 2/4 ohms. I would bet the amp is running out of power when the alternator is charging while driving. Voltage cannot keep up with the needs.

 

[ViperJohn]

I checked the factory speakers, front are 4 ohms and rear is 6 ohms. The Polk DB625 is 4 ohms and I am assuming the fronts are 4 ohms as well.

Would adding a 2 ohm resistor to the Polk rear speaker wiring raise it to 6 ohms?

 

[RTTTTed]

I had Polks in my 98 GTS and I have Hertz speakers in my '01 GTS with MSD plug wires, supercharger, etc. Both my stereos sound fantastic. Engine running makes no difference. Both started with stock head units and both used stock amps.

You have new MSD wires? If the 'popping' is rpm related maybe a shorted plugwire?



Ted

 

[dave6666]

Make sure the plug wires do not cross each other anywhere.

 

[GTSnake]

Does it sound different if you play the radio or CD player? Does it sound different if you rev the engine? I'm guessing it something with your ignition that's causing it.

 

[mjorgensen Woodhouse]

Not sure I have never tried this approach but don't think it will work as the speaker "motor drive" is built for the 2 ohm load and you may damage it with a 6. I guess if it was mine I would just get a adapter harness and an aftermarket amp if you like the clean sounding stereo. You can pick up a good 4 or 5 channel amp for $300- $600 bucks with adapters and call wonderful.

I checked the factory speakers, front are 4 ohms and rear is 6 ohms. The Polk DB625 is 4 ohms and I am assuming the fronts are 4 ohms as well.

Would adding a 2 ohm resistor to the Polk rear speaker wiring raise it to 6 ohms?

 

[ViperJohn]

I had Polks in my 98 GTS and I have Hertz speakers in my '01 GTS with MSD plug wires, supercharger, etc. Both my stereos sound fantastic. Engine running makes no difference. Both started with stock head units and both used stock amps.

You have new MSD wires? If the 'popping' is rpm related maybe a shorted plugwire?



Ted

I played around with the rpms last night and I really didn't notice it make it better or worse. I guess it's possible the rear Polk is bad? Perhaps the vibration of the car running is enough to upset the speaker.

 

[ViperJohn]

Does it sound different if you play the radio or CD player? Does it sound different if you rev the engine? I'm guessing it something with your ignition that's causing it.

If I have the radio on or CD the sound is the same. The only improvement occurs when the engine is off and the car is not moving.

 

[ViperJohn]

Not sure I have never tried this approach but don't think it will work as the speaker "motor drive" is built for the 2 ohm load and you may damage it with a 6. I guess if it was mine I would just get a adapter harness and an aftermarket amp if you like the clean sounding stereo. You can pick up a good 4 or 5 channel amp for $300- $600 bucks with adapters and call wonderful.

I think you may have misunderstood, the factor rear speaker is 6 ohm and the rear Polk that has replaced it is 4 ohm. If the problem is in fact the speaker pulling to much juice from the amp causing a power shortage, wouldn't increasing the resistance in the line to/from the speaker reduce the power shortage?

 

[ViperJohn]

Make sure the plug wires do not cross each other anywhere.

They were carefully run to look neat and match the factory layout. I will double check though, thanks.

 

[Marv S]

The efficiency is the number to consider when wondering how loud the speaker will sound with a given input. give them a 1 watt input and the speaker with 93 db will sound much louder than one with an 88 db spl.

The ohm resistance is not the deciding factor on how loud it will be with 1 watt but it is a factor in how much current it will try and draw from the amp to produce the sound.

The voltage in the car is more constant and stable (and higher) when the car is running above 1,000 rpm than when the engine is not running and the car is on battery only -- providing the regulator is working correctly -. Doubtful that is the issue.

The stock amp just does not draw that much current and should be able to drive those polks ok -

Does the noise vary at all when parked and just moving the rpm back and forth from , say, 1,000 rpm to 3,000 rpm

Did you put any of the stock speakers back in and try things? Switch them out one at a time to see if 1 of the new speakers is defective and causing the problem and loading down the amp.

what is the bass setting on the head unit?

Same volume settings when parked/driving. I am sure the Polk's have a lower ohms rating than the factory speakers, but my understanding is that would allow the speakers to be louder at the same volume setting than stock due to their lower resistance. Also, do you think an ohm difference would explain why this is only happening when the car is being driven? The speakers sound phenominal when the car is parked with the engine off. Thanks for the input.

 

[ViperJohn]

Marv,

Did not notice any change when revving the engine, although I need to retry, weather in our area did not cooperate tonight, so hopefully I will get a chance tomorrow.

I planned on putting the stock sub back in, I have just been dreading going through the process, especially since the wiring is soldered in place.

I am suspicious of the new speaker, I actually have another and plan on switching it out.

Bass setting on head unit is typically at +2, although I did raise it and lower it to see if it made any difference, but it didn't.

 

[Marv S]

John, What did you check the amp for?

There might be a switch on your amp. If so, one position is R (Roadster)-a mono output from the amp to the console speaker and the other is C (Coupe) - a 2 channel output to the 2 speakers in the rear of the GTS.

not sure, but I think the output in the R mode may also change the crossover output on that channel to treat it more like a woofer than a sending it a full range signal.

Hope you get it figured out before the drive to VOI.

After playing with the bass, treble and fader it appears most of the crackling/popping is coming from the rear speaker. I have checked the amp.... .

 

[ViperJohn]

AAHHHHHH, that is what the R and C stand for. I noticed when you set it to one of them, not sure, the bass output is higher. I have tried both positions though, and it did not remedy my problem. I actually am getting ready to go out to the garage and start fooling with the rear speaker in a few minutes.

 

[njred]

I did the same upgrade to the door speakers and replaced the subwoofer with the JL Audio unit(the head unit as well, but using the factory amp)and I am having the same problem. Sounds like a pop pop pop, and it is def coming from the subwoofer rather than the door speakers. I am considering re-installing the factory subwoofer and see if it goes away. I thought from my research on here that it was a pretty straightforward swap.

 

[ViperJohn]

Well.....I have good news to report. It appears the Polk DB650 is bad. I suspect it has something due with the extra power available when the car is on, not 100% sure, however, I also had a JL 6W0 speaker that I had installed a few months back, the reason I pulled it out was because of all the mid frequency trying to be played through the sub. I figured the Polk would sound better. I was willing to trade off some base for better upper and mid frequency output from the back.

Well, I put the amp back in the Roadster setting and placed the JL speaker back in and the crackling is gone.

I really appreciate everyones help and insight into this matter.

 

[dave6666]

I really appreciate everyones help and insight into this matter.

This is the part where we tell you what kind of beer we'd like you to send us right?