Question about wiring and load on monoblock amp

[CleaveTheGreat 10+ year member]

I have a dual voice coil sub that I am powering with a JBL GTO3051 monoblock amp. The guy I talked to at the local car audio shop told me that because the amp is internally bridged, wiring the sub in parallel would present a 1 ohm load to the amp, which it is not stable at. He said the way to wire it would be to connect the negative terminals to the positive terminals on the sub and then connect 1 negative terminal and 1 positive terminal to the speaker terminal on the box and that this would be a 4 ohm load. Does that sound correct? I am new to car audio and this may be a stupid question but I just wanted to clarify before I wire the sub and put it in the box. And also I apologize if the way I explained it was confusing. Any help would be appreciated. Thanks.

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[ObiNev 10+ year member]

Hello, not sure about the specs on the amp .........

But if you have a dual voicecoil 2 ohm sub (each voice coil is 2 ohms), then yes, it is right:

Connect the positive terminal of one coil to the negative terminal of the other coil. Then connect the free terminals to the speaker terminal on the box.

This way you series the coils and produce a 4 ohm load

If you parallel the coils you will get a 1 ohm load

If your amp is 2 ohm stable you will not be getting maximum power from it. You should rather use a dual 4 ohm voicecoil sub and paralell the coils to get a 2 ohm load.

 

[CleaveTheGreat 10+ year member]

Sorry I should have clarified, it is a 4 ohm dvc sub and the amp is 2 ohm stable. The guy I spoke with said that because the amp is internally bridged, I wouldn't be able to run a 2 ohm load with a 4 ohm dvc sub. He said I would have to run a 4 ohm load. Does that sound right?

 

[kr15 5,000+ posts]

Sorry I should have clarified, it is a 4 ohm dvc sub and the amp is 2 ohm stable. The guy I spoke with said that because the amp is internally bridged, I wouldn't be able to run a 2 ohm load with a 4 ohm dvc sub. He said I would have to run a 4 ohm load. Does that sound right?

1-never go back to this shop again

2- dvc4 is ideal for a 2ohm amp

3-wire all your +'s and run to amp +, all your -'s to amp - for 2ohm load

 

[CleaveTheGreat 10+ year member]

Thanks. I didn't think that sounded right, I had never heard that an amp being internally bridged would affect it's ability to run a 2 ohm load from a dvc sub. I'll remember not to go to that shop for anything.