DVC sub wiring; 1 sub sometimes, 2 other times

[drpeeb 10+ year member]

I have a single 4ohm DVC sub now, wired to my Alpine PDX-5, so the amp is seeing the sub as a 2ohm load.

I want to be able to add a 2nd 4ohm DVC sub when my rear seats aren't needed (most of the time).

To do that, I'd need to do some un-wiring of the single sub (inside the box, right now anyway!), and then some re-wiring to add in the 2nd sub ... which is all fine but would require two banana plug panels on the outside of the first sub.

Does anybody else do anything like this?? Is there any other way??

Am I asking for too much cake and eating it too, or something ...

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[Mass Car Audio 10+ year member]

Seeing that the other sub is in a different box just wire the other sub in parallel to the same terminal on the amp as the other sub. You will have 2 sets of speaker wires going to your amplifier in parallel, this way and you wont have to mess around with the other sub box.

 

[squeak9798 5,000+ posts]

Seeing that the other sub is in a different box just wire the other sub in parallel to the same terminal on the amp as the other sub. You will have 2 sets of speaker wires going to your amplifier in parallel, this way and you wont have to mess around with the other sub box.

Except that if he has the subs' coils wired in parallel also, that'd create a 1ohm load which I don't believe the PDX-5 is stable to.

What he could do, however, is leave each subs' coils wired in parallel, and when running both subs wire them in series to the amplifier. Then when you are running 2 subs you'd have a final 4ohm load and when only running a single sub you'd have a 2ohm load. And you wouldn't need 2 sets of terminals on either of the enclosures.

 

[drpeeb 10+ year member]

Except that if he has the subs' coils wired in parallel also, that'd create a 1ohm load which I don't believe the PDX-5 is stable to.
What he could do, however, is leave each subs' coils wired in parallel, and when running both subs wire them in series to the amplifier. Then when you are running 2 subs you'd have a final 4ohm load and when only running a single sub you'd have a 2ohm load. And you wouldn't need 2 sets of terminals on either of the enclosures.

I don't have "series" and "parallel" clear in my head. But here are the two different wiring possibilities for me:

View attachment 26511352

View attachment 26511353

Can you maybe explain a little more how I could avoid two sets of terminals on at least the primary sub box?

It looks to me like there's no other way but to change the primary sub's "jumper" wires when switching between 1 sub and 2.

 

[squeak9798 5,000+ posts]

Leave each sub wired as shown in the first diagram you posted.

Then when you wire the subs to the amplifier, take the positive (+) wire from the amplifier and connect it to the positive (+) terminal on the first subwoofer enclosure. Take the negative (-) of the first subwoofers enclosure terminal and connect it to the positive (+) of the second enclosures terminal. Take the negative (-) of the second enclosures terminal and connect it to the negative (-) amplifier output.

The second diagram you posted has you wiring each driver in series first, then wiring the subwoofers together in parallel (series-parallel). This method is wiring each drivers in parallel first, then wiring them in series together (parallel-series).

 

[drpeeb 10+ year member]

Leave each sub wired as shown in the first diagram you posted.
Then when you wire the subs to the amplifier, take the positive (+) wire from the amplifier and connect it to the positive (+) terminal on the first subwoofer enclosure. Take the negative (-) of the first subwoofers enclosure terminal and connect it to the positive (+) of the second enclosures terminal. Take the negative (-) of the second enclosures terminal and connect it to the negative (-) amplifier output.

The second diagram you posted has you wiring each driver in series first, then wiring the subwoofers together in parallel (series-parallel). This method is wiring each drivers in parallel first, then wiring them in series together (parallel-series).

That is excellent!!! I do appreciate it!!! You saved me from cutting another hole in my primary sub box to add another set of terminals, and switching wires & jumpers around more than necessary. Awesome!

 

[Mass Car Audio 10+ year member]

Leave each sub wired as shown in the first diagram you posted.
Then when you wire the subs to the amplifier, take the positive (+) wire from the amplifier and connect it to the positive (+) terminal on the first subwoofer enclosure. Take the negative (-) of the first subwoofers enclosure terminal and connect it to the positive (+) of the second enclosures terminal. Take the negative (-) of the second enclosures terminal and connect it to the negative (-) amplifier output.

The second diagram you posted has you wiring each driver in series first, then wiring the subwoofers together in parallel (series-parallel). This method is wiring each drivers in parallel first, then wiring them in series together (parallel-series).

Thanks man, I thought he had a 1ohm stable amp when he said he wanted another dual 4ohm sub to add to his set up.

 

[Mass Car Audio 10+ year member]

Are you sure it going to be worth it to add another sub and loose about half the power of your amp ? Your going to loose power at a 4ohm load than a 2ohm load.

 

[drpeeb 10+ year member]

Are you sure it going to be worth it to add another sub and loose about half the power of your amp ? Your going to loose power at a 4ohm load than a 2ohm load.

No I'm not sure, but before knowing enough I bought two 10" Alpine subs ... Might as well try it now I guess, since I also already have enough leftover MDF.

And, according to Alpine and its birth sheet, the PDX-5 puts out the same power at both 2 and 4 ohms ... Rated at 300W RMS minimum, but birth sheet says 424W measured.

Do you doubt either or both of those claims?

I mean, if one Alpine SWS-1043D 10" sub can handle "only" 300W RMS, seems like I should achieve more volume/ bass by delivering 212W RMS to two of them ... No?

 

[squeak9798 5,000+ posts]

Are you sure it going to be worth it to add another sub and loose about half the power of your amp ? Your going to loose power at a 4ohm load than a 2ohm load.

The PDX-5 has regulated outputs so it will output approximately the same power at both 2ohm and 4ohm.

In theory, adding a 2nd subwoofer should still increase output by 3db even though both drivers will be sharing the power.

 

[Mass Car Audio 10+ year member]

No I'm not sure, but before knowing enough I bought two 10" Alpine subs ... Might as well try it now I guess, since I also already have enough leftover MDF.
And, according to Alpine and its birth sheet, the PDX-5 puts out the same power at both 2 and 4 ohms ... Rated at 300W RMS minimum, but birth sheet says 424W measured.

Do you doubt either or both of those claims?

I mean, if one Alpine SWS-1043D 10" sub can handle "only" 300W RMS, seems like I should achieve more volume/ bass by delivering 212W RMS to two of them ... No?

Yes I do believe there are alpine amps that put out the same power at 2 or 4 ohms. (I don't deal with alpine). You should not have any problems with this set up at 4ohms with both subs. Just remember when you double your power to the same speakers you gain 3 decibels, I cant remember what you gain by adding another speaker at the same input power.

 

[Mass Car Audio 10+ year member]

Sorry dude, I did not see squeak9798's last post. So I guess you gain 3db's also by just adding one driver to the same input power.

 

[drpeeb 10+ year member]

Sorry dude, I did not see squeak9798's last post. So I guess you gain 3db's also by just adding one driver to the same input power.

Hey no problem ... In case anyone wants to know, as soon as I build the 2nd box this weekend I'll post what I think the gain is, if any.

If none, I'm taking it back out and getting my limited space back!

 

[drpeeb 10+ year member]

The PDX-5 has regulated outputs so it will output approximately the same power at both 2ohm and 4ohm.
In theory, adding a 2nd subwoofer should still increase output by 3db even though both drivers will be sharing the power.

So here's the comparison:

One 10" sub powered by its rated max 300W RMS power

Two 10" subs powered by 212W RMS each ... Less power each, but more cone area.

I dunno, we shall see ... Might very well be no gain.

 

[drpeeb 10+ year member]

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Leave each sub wired as shown in the first diagram you posted.
Then when you wire the subs to the amplifier, take the positive (+) wire from the amplifier and connect it to the positive (+) terminal on the first subwoofer enclosure. Take the negative (-) of the first subwoofers enclosure terminal and connect it to the positive (+) of the second enclosures terminal. Take the negative (-) of the second enclosures terminal and connect it to the negative (-) amplifier output.

The second diagram you posted has you wiring each driver in series first, then wiring the subwoofers together in parallel (series-parallel). This method is wiring each drivers in parallel first, then wiring them in series together (parallel-series).

Mr. Squeak ... New related question, if you don't mind:

Right now I have one of the 10" Alpine SWS-1043D 4ohm DVC subs wired to the Alpine PDX-5. I've tried squeezing every different shaped box design I can dream up for the 2nd Alpine sub, but I simply don't have enough space for the recommended 1.0 cu-ft sealed box. So, I was thinking of switching the 2nd sub to this 2ohm SVC 8" JL 8W3V3-2 model; It's recommended sealed box size is just 0.3cu-ft, which I can do.

Is there any reason not to connect the 4ohm DVC Alpine and the 2ohm SVC JL sub, wired just like you explained before? I think they're both 2ohm loads, correct?

And ... Would it be absolute heresy to mix and match sub makes/ models/ sizes like this?? //content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif

(The JL would be pretty much completely out of sight, so I don't care that they're different makes/ models)

Thanks for your knowledge!