Jump to content

Constant Distortion on 40hz only


Recommended Posts

Hello,

I recently had a system installed and was not quite happy with the sound quality. I took it back to the installer a couple of times to see if they could figure it out but they always told me it was working fine. I am not a car audio installer by any stretch of the imagination but I wanted to see if I could troubleshoot the system and figure out what. After searching online I came across the DD-1 and ordered one to see if I could address my problems. It sounds like there is a lot of distortion in the music and I get a whine through the speakers if the gain on the amp is over 1/3.

The issue I am running into is that I get the distortion light on before the signal light on track 1 40 hz. This occurs at 15/40 volume and the signal light and 40hz light don't register until 20/40 volume. I have no issues with the 1000hz. I get signal at 20/40 and distortion free until 39/40. I have followed all the instructions, tried other tracks, and have checked the signal at the amp as instructed and from the RCA before the amp.

I am assuming that the next thing to do is pull the head unit out and test the RCA coming directly from the head unit to see if the HU is junk or if the RCA from the head unit the amp is junk. Any advice, guidance, comments would be appreciated.

For reference, the equipment I am using is Pioneer AVH 2400, Diamond Elite Coaxial speakers front and rear (forget the exact but will look it up), Diamond Micro 4 channel, and a self powered Cerwin Vega VPAS12ST.

Thanks in advance!

Link to comment
Share on other sites

I should have clarified that I did indeed have all the settings set to off or flat.

Crossovers were set to flat on the amplifier for the speakers.

Subwoofer gain and boost were set to there minimum values. The subwoofer controller only has 3 knobs: Gain, Boost, and LPF. Should the LPF be set to min or max during the HU volume setup?

Link to comment
Share on other sites

14 minutes ago, Mattizo said:

I should have clarified that I did indeed have all the settings set to off or flat.

Crossovers were set to flat on the amplifier for the speakers.

Subwoofer gain and boost were set to there minimum values. The subwoofer controller only has 3 knobs: Gain, Boost, and LPF. Should the LPF be set to min or max during the HU volume setup?

Whats the subs manual say for set up? Does the HU have RCA outputs for front/rear & sub? If so what are the HU settings at?

Sounds like your doing the right trouble shooting.

Link to comment
Share on other sites

Sub Manual was not included, I have reached out to Cerwin Vega for a copy. 

The HU has outputs for Front R&L, Rear R&L, and Sub R&L. HU settings for everything is flat or off. All speaker and sub decibels at zero.

I should be able to take out the HU today or tomorrow and test it. We already had to reground the sub and amp because they were not done correctly. I am guessing we will have to make a better a ground for the HU as well. Would that cause the issue I am seeing or would it be more related to the HU or RCA cables themselves?

If the RCA cables are the culprit, any suggestions for brands? I am a total noob at this, thanks.

Link to comment
Share on other sites

Alright, I was able to pull the headunit with some friends and test it with the DD-1. The culprit ended up being a ground loop isolator buried in the trunk area. After elminating that and getting everything hooked up properly, we were able to set the gains and the HPF properly.

However, this all in one amplified subwoofer is a whole different thing. I can see signal on in the sub but no matter how high I turn the gain, I don't get any distortion. I called the manufacturer but they were no help in getting it set up. I don't know if anyone out there has any experience with this type of sub and has any guidance.

For now I feel good knowing the rest of the system is working properly. 

Link to comment
Share on other sites

7 hours ago, Mattizo said:

Alright, I was able to pull the headunit with some friends and test it with the DD-1. The culprit ended up being a ground loop isolator buried in the trunk area. After elminating that and getting everything hooked up properly, we were able to set the gains and the HPF properly.

However, this all in one amplified subwoofer is a whole different thing. I can see signal on in the sub but no matter how high I turn the gain, I don't get any distortion. I called the manufacturer but they were no help in getting it set up. I don't know if anyone out there has any experience with this type of sub and has any guidance.

For now I feel good knowing the rest of the system is working properly. 

You have the deck volume all the way up, clean,  any knobs if used in between,,  all the way up, and you see the 40hz signal, but zero clip light? What track did you use at this step?

Also,.. you got the "high pass" set? Set at what?

Edited by Kyblack76
Link to comment
Share on other sites

My max clean volume on the headunit is 39/40 @ 1k hz and 38/40 @ 40hz. I set the speakers through the 4ch amp at 38/40 for the gain and 100 for the highpass as per the manual starting points for speaker size. Both the DD-1 and CC-1 worked flawless in this regard.

For the sub, we went to set the gains by putting the gain and min, bass boost at half, and the LPF all the way up per the instructions. We see signal light using tracks 3, 5, and 7 but we do not see 40hz light or get any distortion light. We tested all tracks available that have are 40hz and got the same result. We also tried the bass boost in multiple positions and LPF at different positions but could only get the signal light (green) but not the 40hz (blue) or distortion (red).

I can only guess with my limited knowledge of this process and equipment that it might have to do with how the powered sub works.

Attached is pictures of what I have to work with for reference. Maybe I am not testing at the correct location on the sub.

vpas12st.jpg

vpas12st cord.jpg

Link to comment
Share on other sites

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.   Paste as plain text instead

  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.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Who's Online   0 Members, 0 Anonymous, 303 Guests (See full list)

    • There are no registered users currently online
×
×
  • Create New...