# how to wire a DVC sub using 2 channels from my 4-channel amp



## Andys2000 (Apr 10, 2009)

I've spent the last two weeks of afternoons and evenings installing a new sound system in my Honda S2000. I pulled out the seats, carpet and door panels. I applied vibration damping, then a layer of thin foam, and finally a layer of MLV to all surfaces.

I installed an Alpine BT136 head unit and ran two sets of RCAs to my PDX 4.100 amp. I used the head unit's subwoofer preamp outputs for channels 3/4 of the amp.

Channels 1/2 go to Alpine 6.25" components in the doors, and I want to use channels 3 and 4 to power my alpine 10" DVC sub (typeS, I believe, around 250RMS @4ohm rated)

*HERE IS MY PROBLEM:*
I ran channel 3 to one voice coil of the sub and channel 4 to the other voice coil. It sounds really underwhelming. I realize a convertible with a sub in the trunk is never going to have ideal SQ, but I can barely tell the sub is powered on. When I open the trunk and look at the speaker, I can see it moving, but only slightly. It produces very little volume. 

*Have I wired the sub incorrectly, or are my amp and sub incompatible?*


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## brandontw (Jan 21, 2012)

Well need to know what sub you have... whether its dual 2 or dual 4.

The amp can handle either, its just how you will wire it. 

You can also bridge channels 3+4 down to a 2 ohm load i believe, so you'd just wire your coils in parallel (if its a dual 4 sub) then hook it up to the bridged output.

Edit: I just saw in there you said it was a 10" type x 4 ohm (dual 4?)

If its really a type X (not a type r) you have to realize its a 500-1000W RMS sub, and you will only be getting 200W RMS either way you wire it, which is bound to be underwhelming.

If you Invested in a Type X, you shouldnt have a problem investing in a dedicated sub amp for that badboy. You could get a PDX mono amp that will stack right on top of your 4.100 i believe.


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## Andys2000 (Apr 10, 2009)

Huge mistake: It's a type S -- the inexpensive one. I'm going to update my original post to reflect that.


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## smgreen20 (Oct 13, 2006)

Make sure you're sending both chs 3 and 4 a mono signal. Even the way you have it wired you will get cancellations from L side programed material vs R side. Will it be drastic, hard to say, probably not.


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## brandontw (Jan 21, 2012)

I think you should try bridging it, and if your still underwhelmed, you may have to start considering more power/ better sub.

Just learn a bit about wiring voice coils, and impedences to make sure that amp is seeing a two ohm load.


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## 07azhhr (Dec 28, 2011)

Is the sub BRAND NEW? If so it will need to break in first but it should still move quite a bit during break in so that may just be an additional factor.

What type and size of box are you running the sub in? 

I see that the amp is only 4 ohm stable in bridged mode so be sure to use it in stereo if your sub is a dual 4 ohm sub. If your sub is dual 2 ohm then you will be ok to series mono the coils to that amp. Either way though you will see the same power output from the amp.


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## 07azhhr (Dec 28, 2011)

brandontw said:


> Just learn a bit about wiring voice coils, and impedences to make sure that amp is seeing a two ohm load.


2 ohm stereo is OK for that amp but the specs I see for it say MONO is 4ohms only. 

Also that amp will deliver 100x4 at 2 or 4ohms reguardless.


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## Andys2000 (Apr 10, 2009)

The sub is an alpine SWS 1043d. If this doesn't answer the questions re: "dual 2 or dual 4" then I can remove the sub from my car and examine it more closely. This speaker was previously installed in my Scion xB. I had it wired in an identical manner in that install, and though the bass output was very underwhelming, it seemed adequate in that enclosed vehicle. 

The box is a ~1.0 cft fiberglass box that I built for my Scion xB. I used the dimensions of the JL Audio stealthbox as a template. I have ordered the material to build a box that will fit into the side of my S2000's trunk, but I am not going to proceed with that build until I confirm that I will be satisfied with the performance of this speaker in my convertible. 

I appreciate your collective expertise. I had not planned to spend more money on this audio install, but I will consider it if what I have will not work.


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## minbari (Mar 3, 2011)

cant beleive no one has suggested this, but make sure you got both pos and both neg wired correctly. if you have one of the leads on backwards, the sub will fight itself and sound pretty much lie you said. (and it wont move much as you said)


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## brandontw (Jan 21, 2012)

Andys2000 said:


> I had not planned to spend more money on this audio install, but I will consider it if what I have will not work.




....and welcome to car audio. Lol.

Seriously tho just double check your wiring. It might just not be enough power ...


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## chad (Jun 30, 2005)

If you are giving it good level, and it's barely moving, make absolutely sure you don't have one of the voice coils out of polarity.

You stand damaging the sub if so trying to get output while one coil is "pushing" while the other is "pulling." The amp will run hotter than hell too.

Edit, Min beat me to it because I did not scroll down... FML.


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## jp_over (Dec 21, 2011)

Subwoofer Wiring Diagrams

Excellent tool!


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## 07azhhr (Dec 28, 2011)

Andys2000 said:


> The sub is an alpine SWS 1043d. If this doesn't answer the questions re: "dual 2 or dual 4" then I can remove the sub from my car and examine it more closely. This speaker was previously installed in my Scion xB. I had it wired in an identical manner in that install, and though the bass output was very underwhelming, it seemed adequate in that enclosed vehicle.
> 
> The box is a ~1.0 cft fiberglass box that I built for my Scion xB. I used the dimensions of the JL Audio stealthbox as a template. I have ordered the material to build a box that will fit into the side of my S2000's trunk, but I am not going to proceed with that build until I confirm that I will be satisfied with the performance of this speaker in my convertible.
> 
> I appreciate your collective expertise. I had not planned to spend more money on this audio install, but I will consider it if what I have will not work.


 1 cft is good for that sub. The sub is a dual 4 ohm sub so DO NOT run it mono to that amp. Well atleast 2 ohm mono...you could try 8 ohms mono since the amp can run at 4 ohms stereo. 

One thing though, and I do not mean to offend if I do, but since this is your thread and question I think it would come across better if you looked up your own information rather then expecting us to do so. All you needed to do was put the subs name in Yahoo or Google to get the answer. 



minbari said:


> cant beleive no one has suggested this, but make sure you got both pos and both neg wired correctly. if you have one of the leads on backwards, the sub will fight itself and sound pretty much lie you said. (and it wont move much as you said)


SO TRUE sorry I forgot to mention that myself. Sometimes it's the little things that get overlooked. LOL.


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## Andys2000 (Apr 10, 2009)

I spent a couple of hours online trying to answer the question. Alpine's product manual for the amp had one diagram for bridging the two channels, but I believe that would only be applicable to a SVC sub. Crutchfield's wiring diagrams are very clear, but when I tried wiring it as they suggested (such that the voice coils each get 4ohms and the amp sees 8ohms) the resulting performance was even worse. Additionally I searched and read through the forums here and could not find a thread that related to my specific situation with the DVCs. 

Thus, I opened a thread. My next job will be to use a multimeter's continuity testing mode to verify that the sub's polarity is wired correctly. I won't be able to do this til Monday though, since I'm working 3x 13hr shifts Friday-Sunday.


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## minbari (Mar 3, 2011)

You can't use a dmm to determine polarity on a speaker. You have to look at the terminals and verify you have them wired correctly. (might mean removing the sub from the box)

BTW, a 4 ohm DVC wired in stereo vs 8 ohm bridged will give you exactly the same power out. Each channel still sees 4 ohms.

Sent from my Motorola Electrify using Tapatalk


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## Andys2000 (Apr 10, 2009)

Alright, well I double checked my connections and polarity, it is all good. I'm still disappointed with the bass output, though. Is there another sub that will produce better output from the 200'ish watts, or am I doomed to disappointment without a new amp AND sub. I wondered if I should upgrade to a 12" at the same time since I've been unhappy with the 10's performance.


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## Andys2000 (Apr 10, 2009)

I played with settings on my head unit, and changing the phase of my sub greatly improved the bass output. Thanks for all the help!


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