Need help with a frequency issue

[Troponin]

I just had my 12 inch CAB ultra and cab 1600.1 amplifier installed. I am very impressed by the overall loudness and SPL of the speaker. I am, however, having an issue with a certain frequency. The box was built to spec, 2 ft.³ and tuned to 35 hz. It hits very low and does not have any problems in the low range, but it hits a certain frequency a little higher and the speaker starts to "pop". The speaker obviously does not like that frequency and it sounds like it could be damaging. I took it back to the car audio place where they tried to fix it for me, but when I got the car back, I noticed the speaker was not hitting as hard. It appears as though all they did was turn down the gain. I went back and I turn the game back up, and the popping came back at the same frequency.

I know a few people have very similar set ups on this forum, so I was really hoping that one of y'all can help me pinpoint the problem and fix it. It's almost as if either the box was not built to the correct specs or it is not being filtered correctly. Is one more likely than the other? I am hoping to just troubleshoot this myself instead of having to take it back again over and over.

The audio shop had the gain turned down to about 40%. What can the speaker handle with this particular amp? I have it turned up to about 80% now and it still sounds good other than the popping up that frequency. It only hits that frequency in certain songs, so for now I've just been turning down the volume with my bass knob to make it go away

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[BSchrowang]

Sounds like the eq on the setup (headunit or bass boost) is turned up too high at that freq. Look through the settings to see if there is a peak in the eq at that frequency or try reducing that frequency a little.

 

[Troponin]

Sounds like the eq on the setup (headunit or bass boost) is turned up too high at that freq. Look through the settings to see if there is a peak in the eq at that frequency or try reducing that frequency a little.

Looks like bass boost is off. What should the LPF be set at? There is another setting for subsonic. What should that be? Should I just turn the bass down to 0 on my head unit? It's a factory head unit

 

[Jeffdachef 5,000+ posts]

Looks like bass boost is off. What should the LPF be set at? There is another setting for subsonic. What should that be? Should I just turn the bass down to 0 on my head unit? It's a factory head unit

Download an app called xplicit audio ultimate car app. There's a frequency generator on there, play the tones in your car and find exactly what frequencies make the sound. Go up in volume slowly. LPF should be somewhere around 50 to 80hz

Bass should be 0 on the factory head unit. The line out convertor has to be driven up pretty high and gain should be minimal.

If your line out convertor cant drive a powerful enough signal, you need a better one that can. Your gains should be around 20-40% max to get strong output not 80%. thats just begging for distortion.

In are seriousness, hope you really think about getting a proper head unit soon because stock head units give very dirty bass signals. A swap to a proper 4 to 5 volt preout head unit will get you 1 db to 6 db louder along with cleaner sounding bass.

 

[Troponin]

Download an app called xplicit audio ultimate car app. There's a frequency generator on there, play the tones in your car and find exactly what frequencies make the sound. Go up in volume slowly. LPF should be somewhere around 50 to 80hz
Bass should be 0 on the factory head unit. The line out convertor has to be driven up pretty high and gain should be minimal.

If your line out convertor cant drive a powerful enough signal, you need a better one that can. Your gains should be around 20-40% max to get strong output not 80%. thats just begging for distortion.

In are seriousness, hope you really think about getting a proper head unit soon because stock head units give very dirty bass signals. A swap to a proper 4 to 5 volt preout head unit will get you 1 db to 6 db louder along with cleaner sounding bass.

Part of my issue is that I drive a hellcat. All of the race settings and diagnostics are through the main head unit. I don't believe any aftermarket head unit is capable of all of the settings. It includes shift light and shift light rpm settings, suspension settings, launch mode...and if there is a head unit that can handle all of this, I have a feeling it's going to be in the $2000 range

They did tell me there might be a workaround that can boost the signal, but it's not quite as good as an aftermarket head unit

 

[Jeffdachef 5,000+ posts]

Part of my issue is that I drive a hellcat. All of the race settings and diagnostics are through the main head unit. I don't believe any aftermarket head unit is capable of all of the settings. It includes shift light and shift light rpm settings, suspension settings, launch mode...and if there is a head unit that can handle all of this, I have a feeling it's going to be in the $2000 range
They did tell me there might be a workaround that can boost the signal, but it's not quite as good as an aftermarket head unit

yeah its called a JL cleansweep, basically restores natural signal from the factory head unit giving you similar signal to what a proper head unit would give and has 8 volt pre-out strength. Probably the only Line out convertor i'd ever think of using. A DSP that can do the same would be the obvious choice but if you can find these units used for 80 bucks, it aint bad.

You can even use an Aux to RCA y splitter and get sound from your phone directly as well.

http://www.jlaudio.com/cl441dsp-car-audio-oem-integration-98110

 

[Troponin]

yeah its called a JL cleansweep, basically restores natural signal from the factory head unit giving you similar signal to what a proper head unit would give and has 8 volt pre-out strength. Probably the only Line out convertor i'd ever think of using. A DSP that can do the same would be the obvious choice but if you can find these units used for 80 bucks, it aint bad.
You can even use an Aux to RCA y splitter and get sound from your phone directly as well.

CL441dsp - Car Audio - OEM Interface - OEM Integration - JL Audio

Made all of the adjustments above and I'm still getting the popping. I'm really worried that they didn't build the box correctly. Would that cause this? I have the gain back down to about 50%, and the low pass filter has been lowered as well.

I'm going to go ahead and get the JL cleansweep and see if that doesn't clean up the sound. Otherwise, I feel like I have to start from scratch again

 

[Jeffdachef 5,000+ posts]

Made all of the adjustments above and I'm still getting the popping. I'm really worried that they didn't build the box correctly. Would that cause this? I have the gain back down to about 50%, and the low pass filter has been lowered as well.
I'm going to go ahead and get the JL cleansweep and see if that doesn't clean up the sound. Otherwise, I feel like I have to start from scratch again

Hold up man before spending money you need to troubleshoot WAAAY more than what you are doing now.

Have you downloaded the app and tested which frequency actually causes that pop?

Whats your voltage drop?

Have you free aired the sub?

 

[Troponin]

Hold up man before spending money you need to troubleshoot WAAAY more than what you are doing now.
Have you downloaded the app and tested which frequency actually causes that pop?

Whats your voltage drop?

Have you free aired the sub?

It's happening at about 50 to 55 hz

I have not free aired the sub

Voltage dropped from 14.5 to 14.4

 

[Jeffdachef 5,000+ posts]

It's happening at about 50 to 55 hz
I have not free aired the sub

Voltage dropped from 14.5 to 14.4

free air it first.

 

[Troponin]

free air it first.

Crap. I have to pull this monster back out of the box? This is going to be a pain in the ***

I don't even know what I'm looking for when I do it, or if I do it.

 

[Jeffdachef 5,000+ posts]

Crap. I have to pull this monster back out of the box? This is going to be a pain in the ***
I don't even know what I'm looking for when I do it, or if I do it.

When you push down on the subwoofer does it make any noise?

check the spiders for any tears, feel the dustcap to see if there's any spots loose or push on it while its playing to see if it stops the noise, check the surround for anything going on, check the tinsel leads.

play a wide range of frequencies and slowly go up on the volume. If its nothing then it would be the box having an issue.

Another thing that has happened to me a lot of times with the popping is from a bad ground, when you measured voltage drops did you do it at the amp or the battery?

Just want to see if we can fix your issues for free first before you shell out cash.

 

[Troponin]

So the sub looks good. No damage appears to be present. The speaker is actually bottoming out, which is odd, considering it's happening at higher frequencies. The shop said it's happening at around 32hz, but changes based on connection method, like Bluetooth vs USB. It hits hard and low without bottoming out in the 20hz range though

Any ideas? They tell me the box is built right.

 

[Jeffdachef 5,000+ posts]

So the sub looks good. No damage appears to be present. The speaker is actually bottoming out, which is odd, considering it's happening at higher frequencies. The shop said it's happening at around 32hz, but changes based on connection method, like Bluetooth vs USB.
Any ideas? They tell me the box is built right.

it shouldnt be bottoming out around tuning frequency because thats close to where the port is tuned at. the closer you are to tuning the less cone movement there is.

This is what bottoming out actually looks like and sounds like at 2:19. Takes a few things to achieve it. over 2.5 x rated power, free air, VERY low 20hz and under notes. If its happening at 50-55hz then it might be some kind of bass boost either inherently in the head unit thats causing some clipping and distortion or a bad amp ground.

Try lowering your high pass to 40hz or so and make sure bass boost is not on in anything.

Actually just set every dial besides gain all the way to the left aka minimum