Jump to content

Welcome to TheMalibuCrew!

As a guest, you are welcome to poke around and view the majority of the content that we have to offer, but in order to post, search, contact members, and get full use out of the website you will need to Register for an Account. It's free and it's easy, so don't hesitate to join the TheMalibuCrew Family today!

Diagnosing sub “static”?


Nick55

Recommended Posts

Nick55

I need some guidance on what to do with my stereo. I am not an audiophile, I don’t raft up at the sandbar and play it for hours key off, and I don’t listen real loud because I don’t feel it’s right to share my music with the entire lake. But my boat isn’t right and I want to fix it.

2008 23LSV, has 4 tower speakers run by a RF Punch 400-4, 8 in-boat Wetsounds Rev6 run by another RF Punch 400-4, and a Wetsounds Recon 10 FA sub with a Punch 500-2 bridged.  The previous owner installed the Wetsounds speakers.  The in-boats and tower sound ok, but the sub is awful.  Last fall I actually pulled the fuse for the amp and didn’t use it.  I don’t have any experience with aftermarket audio systems besides understanding factory units on European  cars.  This is where I have problems with troubleshooting.  

I don’t know what I’m doing or what to describe my symptom as besides I hear static in the sub along with the bass tones. It sounds electrical, not mechanical. It is a steady tone frequency, but changes with the beat of the woofer.

Steps taken:

1) Checked power and ground to amp buds bars, the ground cable is pulled pretty tight so I need to replace it to ensure it’s got a good connection. Head unit and all amps are powered and grounded through same buss bars  
2) Reduced gain on amp to zero
3) removed speaker from enclosure under helm and checked for loose parts in box, checked wiring into box

4) Turned frequency hz up to 100 and down to 40, returned to 60

None of these change the static sound.  I am going to take the next steps of changing RCA cables from the head unit to the amp, then try running new wires from the amp to the sub (in case of physical damage or some sort of interference) then if I have to, will take the sub to a stereo shop and see if they can test it.  If that all checks out, I may end up looking for a replacement amp either to test or just swap out.  

Thoughts?

My reference materials I’ve been using and a pic of my amp settings before I messed with them.

https://rockfordfosgate.com/rftech/library/2007/3_amplifiers/1230_53460_01_rf_punch4ch-man.pdf

https://rockfordfosgate.com/rftech/library/2008/3_amplifiers/1230-54869-01_punch2ch-man.pdf

https://20801275.fs1.hubspotusercontent-na1.net/hubfs/20801275/Sub Enclosure Info/RECON 10 Sub Enclosure Sheet.pdf

IMG_0397.jpeg

Link to comment

Probably the capacitors in the amp.  Do you have LED lighting?  LED strip lights also create a lot of RF noise.

Link to comment
Nick55

The speakers do have LED grilles, I didn’t think about tracing where those are powered from. I’ll look.  Thank you!

Link to comment
3 hours ago, Nick55 said:

1) Checked power and ground to amp buds bars,

What did you check them for? I would want to know all the amps have proper battery voltage at their terminals

3 hours ago, Nick55 said:

3) removed speaker from enclosure under helm and checked for loose parts in box, checked wiring into box

An FA/IB woofer in a small enclosure is less than ideal. Are you positive its the FA version? Its not your issue today but it will hamper performance once the issue is resolved. Due to the helm wall being only a 3/4 wall and open at the top, an FA/IB woofer is not the best choice. You would want a woofer designed for a small enclosure. 

4 hours ago, Nick55 said:

4) Turned frequency hz up to 100 and down to 40, returned to 60

100-120 is more ideal, but again this is not your issue today. Most unwanted noise entering the signal path are above the LP Hz woofer setting. So, I suspect its the amp. With the system off, remove the RCA cables from the amp and power the system on. If the noise is there, its being generated by the amp. Dont be afraid to turn the gain up some, just not more that 50% if the gain is still at 0% and the noise is not initially heard. 

 

LEDs; These rarely enter in on the post-amp output side, but rather the low-level pre-amp side. The above test will narrow this down. Also, LED pulse width modulation (caused by the controller not the actually LED) are usually above the LP Hz filter point and do not get reproduced by a woofer like they do through a full-range speaker. 

Link to comment
Nick55

Today I did the easy stuff first, isolated the power and ground for the amp, then I connected my iPad to the rca inputs to just test if I had a bad cable or output from the black box.  Still had the same noise along with the audio (using the amp adjustments to limit to below 120hz).   Then, I removed the sub from under the helm, and ran a short pair of wires to the amp to isolate speaker level outputs.  Unfortunately, it seems my speaker is bad, as I can tap on the back of the frame and basically duplicate the “static” sound I heard, so I’m going to call Wet Sounds on Monday.  I don’t expect any warranty support but I’d gladly pay for a repair or a replacement speaker.  It is definitely a Revo 10 FA S2 so maybe they can also recommend the correct speaker for that tiny pathetic little box I have (I don’t need big bass or comp level audio, but a little bump is ok to me).

Link to comment
Nick55

Looking at the amp manual, I am not sure a 2 ohm sub is the right choice either. It’s not a dual voice coil and it’s connected to the “bridged” outputs on the amp. 

IMG_0413.png

Link to comment
1 hour ago, Nick55 said:

Today I did the easy stuff first, isolated the power and ground for the amp, then I connected my iPad to the rca inputs to just test if I had a bad cable or output from the black box.  Still had the same noise along with the audio (using the amp adjustments to limit to below 120hz).   Then, I removed the sub from under the helm, and ran a short pair of wires to the amp to isolate speaker level outputs.  Unfortunately, it seems my speaker is bad, as I can tap on the back of the frame and basically duplicate the “static” sound I heard, so I’m going to call Wet Sounds on Monday.  I don’t expect any warranty support but I’d gladly pay for a repair or a replacement speaker.  It is definitely a Revo 10 FA S2 so maybe they can also recommend the correct speaker for that tiny pathetic little box I have (I don’t need big bass or comp level audio, but a little bump is ok to me).

There may something lost in translation but I read nothing that says the driver is bad and the amp is good. 

 

The "HP" version is the woofer designed for a small enclosure. However, the OEM "thing" Bu used is not a woofer enclosure and is too small and full of leaks to work with anything. 

Link to comment
Bluthndr

I have run into this on past cars and one boat once.  In my experience, every case turned out to be that the amp was bad.  In one case it burned the speaker up as well.

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...