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Discussion Starter · #1 ·
Subwoofer link

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This is a drop in replacement for the factory subwoofer driver that still utilizes the factory built in amplifier. The GRS 8SW-4 is a great cheap option that makes a huge difference to volume and sound quality with minor enclosure modifications that don't require full disassembly. poly-fill and mild sound deadening makes a huge difference and helps stops unwanted vibrations. The factory amp pushes around 100watts though this driver which is plenty for lots of sound. SIMPLE WIRING AND INSTALL MAKES IT A GOOD NOVICE UPGRADE

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First post and you're selling something??

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Subwoofer link

View attachment 1211714

This is a drop in replacement for the factory subwoofer driver that still utilizes the factory built in amplifier. The GRS 8SW-4 is a great cheap option that makes a huge difference to volume and sound quality with minor enclosure modifications that don't require full disassembly. poly-fill and mild sound deadening makes a huge difference and helps stops unwanted vibrations. The factory amp pushes around 100watts though this driver which is plenty for lots of sound. SIMPLE WIRING AND INSTALL MAKES IT A GOOD NOVICE UPGRADE

View attachment 1211712 View attachment 1211713
Subwoofer link

View attachment 1211714

This is a drop in replacement for the factory subwoofer driver that still utilizes the factory built in amplifier. The GRS 8SW-4 is a great cheap option that makes a huge difference to volume and sound quality with minor enclosure modifications that don't require full disassembly. poly-fill and mild sound deadening makes a huge difference and helps stops unwanted vibrations. The factory amp pushes around 100watts though this driver which is plenty for lots of sound. SIMPLE WIRING AND INSTALL MAKES IT A GOOD NOVICE UPGRADE

View attachment 1211712 View attachment 1211713
Nice post. Could you be more detailed in how to wire it up and what you used for deadening in the front and what specifically is the white stuff- cotton?
 

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Looks like just poly-fill;
if so, any craft store Michael's, Hobby Lobby, Walmart (?), should have it, even some of the dollar stores.
D
 
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The factory sub is a dual voice coil design. I don't really understand what that means other than it has two pairs of speaker connections. As a result, I replaced mine with a sub that also had dual voice coils. Is this sub dual or single voice coil? If single, how does this sub wire up, given that?
 

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Discussion Starter · #7 ·
Nice post. Could you be more detailed in how to wire it up and what you used for deadening in the front and what specifically is the white stuff- cotton?
Sound deadening is killmat from Amazon and the white stuff is poly-fill "synthetic pillow stuffing" wiring is just connecting the two output pairs into one and plugging it into the speaker.
 

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Discussion Starter · #8 ·
The factory sub is a dual voice coil design. I don't really understand what that means other than it has two pairs of speaker connections. As a result, I replaced mine with a sub that also had dual voice coils. Is this sub dual or single voice coil? If single, how does this sub wire up, given that?
It's single 4 ohm. The factory one is dual 3 ohm wired parallel so it's a 6 ohm speaker. Just tie the two output pairs into one. The amp can handle the lower impedance just fine. Mine has been installed for 2 years with no issues
 

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First post and you're selling something??

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Not selling something just trying to let people in on my budget upgrade while the driver is only $20 when I bought mine for $35. I love the factory enclosure and this retains it without adding an aftermarket amplifier while still sounding great.
 

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Not selling something just trying to let people in on my budget upgrade while the driver is only $20 when I bought mine for $35. I love the factory enclosure and this retains it without adding an aftermarket amplifier while still sounding great.
Then welcome!
 

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First post and you're selling something??

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For people interested/curious.... vendors have to pay to advertise on this site... hence the questioning since this was his first post.

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thanks for the suggestion, just ordered one to give it a shot-- price is right and hoping this gives a little 'extra' to the sub without a full replacement
 

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well, crap. Spliced green pair of wires together and purple pair of wires together into new speaker....and... nothing.

OEM wiring/sub BEFORE:

Automotive tire Automotive design Gas Space Rim


Replacement subwoofer AFTER:
Tire Wheel Bicycle wheel Bicycle tire Bicycle wheel rim


All i hear is a very faint static on the bass notes, same result switching the leads to opposite terminals on the speaker. The factory sub was working ok before this, was just hoping for more 'oomph'. I do have an aftermarket Alpine head unit (without an add-on amp) if that makes a difference, although like i said the stock sub was working ok before the swap. what did i miss?
 

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well, crap. Spliced green pair of wires together and purple pair of wires together into new speaker....and... nothing.
...
what did i miss?
The OEM subwoofer is a two channel amplifier driving a dual voice coil speaker. The purple pair is one output, the green pair is the other output. You've just shorted each amplifier output together in your terminal crimp. Hopefully you didn't fry the amplifier. Use a dual voice coil speaker and wire it properly.
 

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The OEM subwoofer is a two channel amplifier driving a dual voice coil speaker. The purple pair is one output, the green pair is the other output. You've just shorted each amplifier output together in your terminal crimp. Hopefully you didn't fry the amplifier. Use a dual voice coil speaker and wire it properly.
That makes complete sense...but curious how the OP used the OEM wires to the same speaker and made it work? Looking for a replacement 8"Dual Voice Coil speaker now.
 

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It would appear that the OP connected the two amplifier outputs in parallel which is a bad idea. The two amplifier ouputs are stereo, one for left, one for right. When there are differences between L and R, one amplifier will have a different output than the other. If the amplifier outputs differ and are wired together, then a large current will flow briefly while there are differences and lead to distortion and waste a large amount of amplifier power and be hard on the amplifier output transistors. Most music has little stereo content at low frequencies so sometimes it will seem OK.

To be more technical, the reasons not to parallel amplifier outputs comes from that each amplifier has a separate negative feedback loop that corrects the output signal to match the input signal multiplied by the voltage gain so that an output error gets negatively amplified to try to force the output signal to be correct. With a second amplifier directly connected to the first one, then the two will both fight to make their separate left and right signals correct but the outputs are being forced to be identical by the short circuit of the two channels in parallel. This is bad. Don't try to run one speaker coil with two amplifiers.

If the two amplifiers have their input signals first going into a summation amplifier to sum L+R to mono at the amplifier inputs (it may have this), this will minimize the signal differences and improve efficiency driving a dual coil speaker, but still there are slight differences in amplifier gains and response due to component tolerances so a dual coil speaker is needed if both are to be used and get the power of both amplifiers used. Two separate speakers would be great too but would take too much space.

When you use a dual coil speaker, then each coil produces a separate magnetic force, but are electrically isolated. The net sound wave is the vector sum of the two signals. Putting both amplifiers in parallel on one voice coil doesn't get you any more output power anyway since the voltage gain is fixed, and one amp by itself can easily drive the 4 ohm load.

If you are going to use a single coil speaker, you'd be better off just using one of the amplifier outputs. The original poster was incorrect about the coils being in parallel, they are actually on separate amplifier channels. Also incorrect that two 3 ohm loads in parallel makes 6 ohms (it would make 1.5ohm).
 
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