ID12v3 x JL XD700/5 low output issues

[neo_styles 10+ year member]

Another question: how many RCAs do you have going to your amplifier? Worst case, you can change the input switch to 2 or 4 channel and see if it'll sum the signals. That can help you isolate a faulty RCA but you'll lose the sub control from your HU.

 

[wanton789 10+ year member]

You should be setting your gains without the sub connected. Then connect the sub and leave it well enough alone.

Roger that. I'm not about to hook it up with the gain bumped up crazy right now though.

Now I learned how to actually measure the RCA (signal to ground, not signal to signal).

I still read 0.00 VAC or 0.01. I checked the multimeter manual and it goes down to 40 Hz so I should be ok with a 50 Hz tone (I also checked a 170 Hz tone).

RCAs could have fallen off your HU too.

RCAs are def not fallen off the head unit as I have it out right now.

If it was bad RCAs, then one of the lines would be completely dead. But I got a signal out to my sub and it was just barely startin to bump with that 3 V @ 50 Hz.

 

[wanton789 10+ year member]

Another question: how many RCAs do you have going to your amplifier? Worst case, you can change the input switch to 2 or 4 channel and see if it'll sum the signals. That can help you isolate a faulty RCA but you'll lose the sub control from your HU.

Right now only the sub channel. I tried switching the amp to 2 or 4 channels but you need it on 6 channels if you want the sub channel turned on.

 

[neo_styles 10+ year member]

You might be getting some feedback. Doesn't make sense that you're getting signal with a 0Vac reading on the DMM. The RCAs should be putting something out. Change the DMM to Vdc and see if that changes anything.

 

[neo_styles 10+ year member]

Right now only the sub channel. I tried switching the amp to 2 or 4 channels but you need it on 6 channels if you want the sub channel turned on.

From what I read in the manual, it'll sum the sub signal in 2 or 4 channel mode rather than cancel it out as long as the RCAs are connected to channels 1 and 2 or 3 and 4. 6 channel is only required when using channels 5 and 6 where they're summed to mono.

 

[neo_styles 10+ year member]

Checked the HU manual. Try looking in your HU settings and make sure Dual Zone is disabled and Subwoofer is selected to Small or Large.

 

[wanton789 10+ year member]

Ok I found some of the problem...

Need to turn off the HU amplifier if you are going to get anything from the preouts. So I do this and read 0.7 VAC out the RCAs of my HU. Ok great.

Now that ~0.7 V goes through to the subwoofer speaker outs on my amp with 0 gain.

Now I turn everything down (HU, aux input from FreqGen on iPhone, amp gain)... wire up my sub.

Turn it on, slowly increase volume, and I got nothing. Turned up the HU volume, iPhone volume to full, made sure I was still on Aux input. Gain on amp is 0 at this time. Slowly turn up amp while reading with DMM... Go all the way to 10 VAC, nothing.

I beep checked my RCAs, beep checked the whole signal path all the way to the dual voice coils. Everything is cool.

Now I got a problem.. lol

edit: also flipped between 2 4 and 6 ch settings on amp. Also made sure LPF wasn't cutting out the 50 Hz signal.

 

[neo_styles 10+ year member]

I'd say you do. I'm thinking something is interrupting your signal path in the amp.

Try this: using a headphone jack to RCA adapter, connect a MP3 player to your amp's input and set it to about 50 percent volume. Now slowly bring up the gain to see if you get input. If the MP3 player produces sound from the sub, you know it's either the HU or RCAs. If you still have nothing, it's the amp or sub.

In the twidget world, we call this "half-splitting"

 

[wanton789 10+ year member]

Man...

The "Built in Amp" setting wasn't even the problem. It says turning off the built in amp only increases the sound quality from the Preouts.

I tried with my iPod to RCAs straight into amp, bypassing the HU, got nothing. My iPod at half puts out a 1V signal.. actually stronger than the HU.

Man... I must have f'd something up... The sub is motionless.

 

[neo_styles 10+ year member]

If you have any other speakers you can wire to the amp, it'll help you verify the sub is your problem. At least we can safely assume it's not the HU's fault now.

Try testing a different sub (ask a friend) using the MP3 player method. If sub no worky worky, you know it's the amp.

 

[wanton789 10+ year member]

The only thing I can think of is when I "thought" that the it was the "turn off built in amp setting" and I got a signal through out the RCAs that was greater than 0.01...

At that point I had the sub wired up, though no sound coming out. With 0 gain on amp, heard nothing, so turned it up to ~10 something. It was increasing at the rate that it did when there was no load attached.

From your experience, when everything is working properly, does the gain when you have no load increase similarly to when you have a load attached (as far as how rapidly the voltage goes up on your DMM?).

Is it possible I blew it out tthen by turning up the gain even though no signal and no movement of the cone or anything?

 

---------- Post added at 09:44 PM ---------- Previous post was at 09:44 PM ----------

 

Yeah I'll just forget aboout the sub tomorrow and hook up my fronts and see if everything is ok.

 

[wanton789 10+ year member]

Well.. I blew out my sub. Resistance between the + and - terminals is infinite..

 

[wanton789 10+ year member]

I really don't know how..

 

[neo_styles 10+ year member]

Could have been like that from the beginning man. Stuff happens. Just learn from it and next time you set your gains, don't have your speakers connected. Use the DMM method every time and Ohm's Law will be your friend. Hopefully you can get a replacement sub on the cheap.

 

[wanton789 10+ year member]

I think I destroyed it from that very beginning time when I was seeing 2-3 Volts out and the amp was trying to protect itself.