Need help troubleshooting an amp

  • 3
    Participant count
  • Participants list

Fuzion64

Junior Member
31
1
BFE
Long story short had my gain set running a test tone of 50Hz 0db
When out of nowhere I heard a 1 hz - 1khz sine wave test start from youtube without being selected due to the annoying youtube autoplay feature being turned on
At this point my volume was at 85% since I was alternating between music and a test tone. Next thing I know I hear a rattle from my sub and smell a burning smell.

Dang autoplay I never expected youtube to launch a 1khz sweep thru my sub especially at 90% volume.

I rushed to turn it off as quickly as I could, but by then the damage was done.

Its a kenwood 9106 so I very much doubt pushing a mere 500w-600w thru it blew it since its rated for 1000w up to a peak of 2000w

Now when a sub is hooked up it vibrates at a very low volume, but there is no punch behind the bass.

How do I test my sub and amp to see what all damage has happened. How do I make sure my 200a fuse is still intact. It looks exactly like this.


20560


What would this look like if it got damaged?


Thanks
 
2 key things that raised my eyebrows right away: Rattling from subs and burning smell. I would def check your subs with a small household battery....or DMM if you have one. If no coils show some sort of number, consider them toast.
 
The sub has a scratchy sound when I check it on a 9v, but it doesn't move at all reguardless of polarity.
This is when I put the silver wire on the biggest connector and the copper wire on the smallest connector on the 9v

I think the reason it blew or recieved the damage was the fact I had the volume up for testing and I had to LPF all the way up to 200hz so when that frequency sweep went thru the system it messed up my components. Watch out for youtubes autoplay feature the frequency sweep comes right after the tone.

My advice put the tone on its own playlist by itself and set it on loop.

Its a 12" 4 ohm DVC that was connected in parallel so it was setup for 2 ohms which I didn't know. I only found this out when I went to check everything after it had happened. My voltage was configured for 4 ohms since I didn't know it was wired for 2 oms (Almost double), but I was using the radio too like jeff has previously suggested. I just wanted to make sure I would not exceed 250 RMS, but since I didn't know the shop had set it up for 2 ohms it most likely cost me a sub by exceeding it.

So here is the steps I have taken so far using a DMM at AC 200
Checked the amp voltage by increasing and decreasing watching a multimeter (works fine, voltage still rises and falls)
Checked the Monster (200a fuse under the hood for continuity (0.00 - intact)
Checked the (3) 40a fuses on the amp (No broken circuits)
Checked each speaker wire individually for continuity (All came back fine - 0.00)
Installed a new sub - It vibrates minimally, but it doesn't hit at all even when I go up thru the volume. I know its in phase, because I checked the whole wiring configuration from the amp to the sub. Its like the sub is getting power, but not pushing out bass at all. I can put my hand on it and feel vibration, but its not much at all.

Checked each sub...
My previous Memphis Audio 250 RMS/ 500w makes a scratchy sound, but doesn't move the sub at all with a 9v test


Next I tested another brand new sub that I bought earlier today
Pioneer 400 RMS /1500w shallow works fine on a 9v, but plays minimally in the car when connected.
(Determined forward polarity In phase - Dark Green/Copper = Positive | Light Green/ Silver = Negative)

I think the amp is in protect mode so I will most likely try to reset it next by pulling the red battery cable for 30 seconds, then reconnecting.

Update: Voltage readings (VOM AC 200 - Memphis Audio 12" 4 ohm DVC wired parallel to 2 ohms)
The resistance on the left voice coil individually reads 4.2-4.3
The resistance on the right voice coil individually reads 4.3-4.4
The resistance on the main speaker wire ends that would goto the amp with the subs wired in 2 ohm parallel read 4.4 using AC 200
Sub makes a a scratchy sound when I connect it to a 9v, but the cone does not move forwards or backwards.
 
Last edited:
Bass issue solved:
Sub was blown and for some reason the iphone was muted when rca's were plugged up.
If you connect your iphone to a pioneer deck don't forget to turn back up your volume before you ever turn on usb/bt. The iphone does not automatically turn back up the iphone audio when you plug it into your headunit. Once you plug in a usb or switch to any other device with your iphone usb'd you lose the ability to adjust the actual iphone volume beforehand.

If I set my iphone at 25% of its volume, then plug it in via usb it will play that sub at the 25% volume. Never going up to 100%. I also lose all ability to control the iphone internal volume the second the usb is plugged in or bluetooth is synced.
So always check the iphone internal volume beforehand. The pioneer headunit does not crank it up automatically when its plugged in via usb or bt. It stays at what it was set at before plugging in. Now whats funny is the phone volume will show 100% when I look at it thru the phone with usb connected or bluetooth connected, but the bass going out of the music will be the hidden iphone setting at the min 25% since I never increased it before switching to bt or plugging in the usb.

If you have pioneer headunit I would definately keep this in mind, because it matters that you only get the volume your phone was set at before you plugged in the usb.

Try this turn down the ringer on your iphone to 0 disconnected from the usb
plug in the iphone via usb, now look at the volume on your iphone with usb connected it will say 100% (LIES)
You'll notice that your actual bass coming out of the iphone will be locked at 0%
Even increasing the volume control on your headunit will not fix this. The unit thinks you only want the iphone to play at 0%.
You would think that the headunit would automatically max out the usb/bt device volume when it gets plugged in since you are riding in a car and listening to music, but it doesn't. This is where my hiccup was I thought the phone automatically increased to the appropriate volume when I hooked it up. I never thought to check the internal iphone volume before connecting the device, because the iphone showed 100% volume when connected via usb, but the output was still at 0% of bass.
The only way to adjust this is to unplug the iphone via usb, then up the volume and then hook it back up to the usb.
Once bluetooth sync's you cannot change the phones internal volume. You have to turn the car completely off and set the iphone volume then restart the car. Switching to radio and trying to up the iphone internal volume won't help. The car must be off when doing this to correct the issue using bluetooth.
Bingo now your bass hits again. The culprit was nothing more, then a internal iphone volume setting that was hidden away once synced or connected.


Moving on...
Had a full bench test done on amp - its fine
Bought a new sub - works great
P-Con blue remote had come loose and was causing a short while driving. This is why the amp randomly would turn on and off.
SLA had reset itself down to 0 so it was like there was no bass coming thru the system.
Bass was completely missing with a pioneer headunit until SLA was back to 4

Added a 2 ohm rockford shallow P3 to my setup - Hits alot harder than my memphis did.
The pioneer I bought wouldn't fit in the box because there is a wedge mid center making it impossible to fit.
Unfortunately amazon doesn't allow a return on it so now I have a pioneer TS-SW3002S4 for sell. Its brand spanking new NEVER used for $80.00.

Back to the troubleshooting...
After all the troubleshooting headache I went thru the only thing that mattered was putting a single SLA 0 back to 4 and setting my iphones internal volume before connecting via usb or syncing bluetooth. Now it hits again the way it should with no bass boost whatsoever. With SLA at 0 the bass is so horrible it makes all the money I spent on my system extremely disappointing. I want that thump! SLA 4 brings that thump back. At SLA 0 the bass is so minimal that you can barely feel anything at all. I mean anything, its such disappointing bass even at 40v (400 RMS)

If you have a pioneer deck and you are experiencing very little bass check the SLA and the phones actual volume before ever syncing or plugging in I cannot stress this enough. I wasted hours trying to solve a poor bass issue because I thought the headunit knew to max out any connected or synced device volume as soon as it gets plugged up.

My phone ringer was on 0 because I turn it off when I goto work. I never thought the headunit would leave it at 0 when I plug it up to listen to my stereo.

Why would I want a iphone to sync at 0% or 25% I could turn the device up or down using the volume control of the headunit once the device is synced at max level if the headunit automatically maxed all devices internal volumes. Is it wrong to assume that the headunit should have automatically done this as soon as I connected the device or synced it.
Even the phone showed 100% on volume, but it was actually still at 0%

Sorry for repeating this over and over, but I really wanted to stress the point of the iphones internal volume beforehand to help others who may be having the same issue. Hopefully this can help them solve a low bass issue with a pioneer deck.

Many times we adjust our phone volumes while doing things, but we never think to re-adjust it again before we connect it to the headunit. This is because we assume the headunit knows to put the devices volume at 100 on any new connected device as soon as its connected or synced. The iphone will trick you by showing 100 when its connected or synced, but its only going to use the volume setting before it was connected or synced in.
 
Last edited:
I use a lightning to usb cable and have my Pioneer set to wired app control. This disables the phone volume capability once plugged in. Once plugged in the deck volume is your loudness no matter what the phone volume is set to beforehand. If I have the app control set to bluetooth I regain phone volume capability but I prefer to not have it.
 
Activity
No one is currently typing a reply...
Old Thread: Please note, there have been no replies in this thread for over 3 years!
Content in this thread may no longer be relevant.
Perhaps it would be better to start a new thread instead.

Similar threads

I would try a pair of Bass Blockers on the rear speakers. I always place them on Coax. speakers generally, Should help quite a bit I like PAC ones...
3
317
https://youtube.com/@SaabUnleashed?si=-8qdxpYY0yGzrMsL Here you go. This guy does android head unit reviews. His reviews are how I found my...
7
678
If you want 5 channels of amplification you just need 5 channels of amplification. You can do this with 5 amps or 1, depends on budget and space...
1
418
All you need. I've been running these for years in 3 different vehicles. https://www.amazon.com/dp/B01BL57JO2/?tag=caraudiocom-20
2
592

About this thread

Fuzion64

Junior Member
Thread starter
Fuzion64
Joined
Location
BFE
Start date
Participants
Who Replied
Replies
4
Views
743
Last reply date
Last reply from
2RZ-FE
Screenshot 2024-03-07 184329.png

Doxquzme

    Mar 27, 2024
  • 0
  • 0
IMG_3075.jpeg

Daniel Lee

    Mar 27, 2024
  • 0
  • 0

Latest topics

Top