So I bought a Tantric HD 12 d2 a week ago and received it yesterday. Today I went to put it in my 2.5 cu enclosure and I am having a problem with the sound/voltage. It doesnt drop ( to maybe low 14s) and something is definitely wrong. I had a problem similar to this last week when I realized my coils on the mayhem were toast. Voltage drop with zv4 was to around 12 volts. The way it is playing seems as if it wired very high.

 

What I did:

-Checked coils on sub (read 2.4ohm each)

-impedance at the output terminals is 1 ohm (car off)

-o-scoped the rca's and output voltage (clean)

- free aired the sub and notice no coil rub at all (seems as if not getting full power) and it sounds perfect

- sub appears to be in mint condition

- changed port tunings (didnt help)

 

 

Only thing I can think of left:

- check power/ground input (dont think this is going to do anything)

 

 

I really need some help guys been out of bass for 2 weeks and cant figure this problem out.

The voltage doesn't drop so something is wrong??

The voltage doesn't drop so something is wrong??

Yea man when the D2 mayhem was working my voltage was dropping into 12s, theres no way im getting a current draw of atleast 150 amps and only dropping under a volt.

Could it be the amp? Head unit?

You checked the coils independently but not how they are wired?

You checked the coils independently but not how they are wired?

I stated in my first post that I measured the impedance at the output terminals when wired in parallel and I get 1.2.-1.3 ohm.

Could it be the amp? Head unit?

o scoped the rcas and checked voltage on it so it cant be head unit. amp I couldnt tell you.

Did you accidentally turn down the gain, adjust the subsonic filter, or low pass function?

Partially blown fuse?

J

Did you accidentally turn down the gain, adjust the subsonic filter, or low pass function?

Partially blown fuse?

J

The sundown 2000d doesnt have any internal fuses and Im not fused in between my second battery and the amp. The gain is fine because I o-scoped it, the subsonic filter is all the way down.

Could it be the amp? Head unit?

o scoped the rcas and checked voltage on it so it cant be head unit. amp I couldnt tell you.

Should probably try a different amp if your able to

Did you accidentally turn down the gain, adjust the subsonic filter, or low pass function?

Partially blown fuse?

J

The sundown 2000d doesnt have any internal fuses and Im not fused in between my second battery and the amp. The gain is fine because I o-scoped it, the subsonic filter is all the way down.

Why is it all the way down!!?

 

 

Did you accidentally turn down the gain, adjust the subsonic filter, or low pass function?

Partially blown fuse?

J

The sundown 2000d doesnt have any internal fuses and Im not fused in between my second battery and the amp. The gain is fine because I o-scoped it, the subsonic filter is all the way down.

Why is it all the way down!!?

 

Trying a different amp was my next move... but dont have an extra lol. My subsonic is all the way down because im tuned to 22

Did you test the amperage?

Did you test the amperage?

of what?

Well voltage is one thing...Amperage is the rate of flow.

You can have low amperage flowing into the amp causing less output.

Like an alternator or battery gone bad maybe?

Well voltage is one thing...Amperage is the rate of flow.

You can have low amperage flowing into the amp causing less output.

Like an alternator or battery gone bad maybe?

I can check the AC current at the output terminals, but if it was a battery or alternator problem I wouldnt be holding voltage.

Was your Zv4 in the same box?  

 

Just a thought, but if you are tuned to 22 Hz and aren't playing anything with content that low your amperage draw is going to be less.  As you get away from your tuning frequency the impedance rises, while your amp will be putting out the same voltage the amperage will be less.

 

Of course if you are using the same tuning and playing the same music as before you can ignore what I just said.  

Was your Zv4 in the same box?  

 

Just a thought, but if you are tuned to 22 Hz and aren't playing anything with content that low your amperage draw is going to be less.  As you get away from your tuning frequency the impedance rises, while your amp will be putting out the same voltage the amperage will be less.

 

Of course if you are using the same tuning and playing the same music as before you can ignore what I just said.  

Yea man I had the same Idea, thats where I swapped out the 22 hz port back for the 32 hz port and nothing changed. Its really a problem because even when I free air the sub I barely get any voltage drop. Im going to spend some time today getting some output voltage and current numbers.

I checked my AC output voltage and it is only 32 VAC which seems low... So the amp isnt making the power or the load is higher than what it appears to be. It must be the amp because the output terminals read 1.0-1.3 ohm when the car is off.

Change back to your old sub and so the same tests. See what is wrong.

J

When you say you've checked the resistance at the output terminals, are you saying you're checking the sub's resistance at the terminals of the amp?

 

Also, since it looks like you have all the tools at your disposal to do it, play tones from 20hz up to where you have your LPF set and measure the voltage and current.  Then use Ohm's law to find resistance and plot the impedance curve to see if anything about that looks funny.

When you say you've checked the resistance at the output terminals, are you saying you're checking the sub's resistance at the terminals of the amp?

 

Also, since it looks like you have all the tools at your disposal to do it, play tones from 20hz up to where you have your LPF set and measure the voltage and current.  Then use Ohm's law to find resistance and plot the impedance curve to see if anything about that looks funny.

I see... I went to measure the AC current output at the terminals of the amp but when I had a 30hz tone going and put the leads onto the screws It was sparking. That was only trying to read the AC current, it wouldnt do this when I measured AC voltage.

 

and yes I measure the subs resistance at the terminals of the amp and I get like 1.3 ohm

Edited March 14, 201510 yr by khinds94

Change back to your old sub and so the same tests. See what is wrong.

J

I would do that If I had another sub that was working... the mayhem has bad coils and the Zv4 had burned leads so I need to recone them both.

 

I used an Alpine sub free air that my friend had and the voltage drop to low 14s at 2 ohm which still doesnt seem right.

You can't measure it like that.  If you measure resistance while it's hooked up at the amp you're measuring the resistance of the sub and the internal circuitry of the amp together.  You have to disconnect the sub from the amp to measure the resistance of the sub at that point.

 

You have to put the meter in series with the wiring to measure current.  I thought you mentioned having a clamp on meter?  Use that to measure current and the probes to measure voltage.  If I misread about the clamp meter, sorry, I didn't catch it right.

You can't measure it like that.  If you measure resistance while it's hooked up at the amp you're measuring the resistance of the sub and the internal circuitry of the amp together.  You have to disconnect the sub from the amp to measure the resistance of the sub at that point.

 

You have to put the meter in series with the wiring to measure current.  I thought you mentioned having a clamp on meter?  Use that to measure current and the probes to measure voltage.  If I misread about the clamp meter, sorry, I didn't catch it right.

I measure the resistance at the terminals with the car off.

 

But I dont have a clamp, can I get one at like home depot?