Amplifier + Sub wiring help

[bergeron37]

Couple of question regarding my stereo installation, hopefully you guys can give me some feedback. I’ll give you some details:

I have replaced the front speakers and head unit with all alpine products. My buddy used to have a pair of Alpine Type r12 (12 inches) in a custom box in his jeep however; he took them out about a year ago for space reasons.

I purchased an 800 watt Sony Xplod 2 channel amp. My buddy and I are going to build our own boxes so that we can each have one r12 sub.

Few questions:
What would be the best way to wire this? I had not planned on powering the front speakers through the amp, just the head unit and subwoofer.

Also where would you consider the best place to mount the amp? I’m guessing I am just going to mount the amp to the back of one of the rear seats and put the box directly in front. That way I can still put one seat down to haul ****.


Let me know what you guys think is the best method? I’ve done everything else myself and would love to be able to do this myself as well.

Here are some specs on the two:

Subwoofer
• 12" subwoofer with dual 4-ohm voice coils
• Kevlar reinforced pulp cone with Santoprene™ rubber surround
• cast aluminum frame with perimeter venting
• frequency response: 25-500 Hz
• power handling: 200-500 watts RMS (250 watts per coil)
• peak power: 1,500 watts
• sensitivity: 85 dB
• top-mount depth: 7-5/8"
• sealed box volume: 0.57-1.0 cu. ft.
• ported box volume: 0.75-2.0 cu. ft.

Amplifier
• RMS Power Rating:
o 4 ohms: 130 watts x 2 chan.
o 2 ohms: 170 watts x 2 chan.
o Bridged, 4 ohms: 340 watts x 1 chan.
• Max power output: 800 watts @ 2 ohms
• OTL Output transformerless circuit pulse power supply
• Tuned Bass EQ (0-10 dB bass boost at 40 Hz)


Thanks for the help in advance everyone!

 

[Offroader5]

Well, since that sub is dual 4 ohm coils, that amp can really only be hooked up two ways.

You can either wire the sub coils in series to net an 8 ohm load running the amp bridged mono to the sub netting about 150-200 watts MAX (if that amp actually puts out rated power).

or....

You can run the sub in stereo (not my favorite configuration for DVC subs) and just connect each amp channel to it's own coil on the sub netting the 130 watts to each coil (again...if the amp actually does rated power).

It doesn't appear that amp is stable in 2 ohm bridged mono. If so, that would be the best way to wire it to a dual 4 ohm coil sub.

 

[bergeron37]

Thanks for the quick response.

It sounds like I should go with the first option as that puts the most power?

 

[Offroader5]

Actually, the second option is more power. If you wire each channel to one voice coil, each voice coil would then receive that channels rated power. If the amp puts out 100 watts continuous x2 to 4 ohms, then each 4 ohm coil would get 100 watts equaling 200 total to the sub.

The first option would require you to wire the sub coils together in series and this doubles the ohm load meaning two 4 ohm coils wired this way would give one input at 8 ohms. Running a 4 ohm amp channel into an 8 ohm speaker load would roughly cut that channels rated power in half. So, using the amp spec you posed above for a 4 ohm mono (bridged) channel @ 340 watts, running this bridged channel into an 8 ohm speaker load would give you about half that...about 170 watts. That's PEAK though and not continuous power.

 

[4D7]

OP, your amp is not a decent match for your sub.. Your amp is under powered (by safe statndards)

What I would do since those amps are a dime a dozen is run that sub into a 2ohm load (wire sub positive to positive and negative to negative). This will allow your amp to run at a 2ohm load in bridged mode (even though it isn't stated). Keep the gain down on the amp a bit as your amp will be nearing 500Wrms. With this being outside the amps comfort zone it may get hot. Test it out an monitor temps - some amps will hold up to the abuse, others won't.

In all honsety your amp will either immediately shut off and go into protect mode, or it will pound your subs guts out for a few months and then die.

Happy installing!

 

[bergeron37]

4D, OffRoader thanks for the input.

Basically Offroader's option is the most power while keeping the amp safe, and 4D's is the most power possible until the amp dies (which is what i inevitably expected).

If i may ask, what amp would you suggest in terms of wattage/rms/channels?

I have aftermarket speakers in the front too so what if i wanted hook those up in the future, 4 channel?

I really only envision hooking up the sub so just disregard the last question if you want. Thanks a lot.

 

[bergeron37]

Would this amp work any better?

Pioneer GM-5300T 2-Channel 760-Watt:

Peak Music Power - 760-Watts
4 Ohm 125 Watts x 2 Output Power
4 Ohm Bridged 380 Watts x 1 Output Power
2 Ohm 190 Watts x 2 Output Power
1 Watt into 4 Ohms 75 dBA Signal to Noise

Or should i just get an Alpine mp-500

 

[Offroader5]

that amp is still not 2 ohm mono capable which is what you really need for that dual 4 ohm voice coil sub. I'd look into the new PPI Phantom amplifiers. Lots of bang for the money and you get good power. You get rated power plus...and not only max power like many amplifiers put up as their RMS (continuous) power. Also look into Massive Audio Nano amps. Again, good amps..and they are very small. You shouldn't have any problems finding one amp that can power your whole system that has a very small footprint and a relatively low cost.

I run a PPI Phantom 1000.1 to my Alpine Type-R 8"DVC and even though it's a bit more power than it should be getting, it pounds. I've fooled many into thinking I'm running two 10's or at least a 12 on high power..and they were in awe when they realized it was one 8. It is usually more about the enclosure though than how much power you can feed the sub.

 

[bergeron37]

I posted the wrong sub. Its an Alpine r12 but its only the dual 2 ohm. I believe they come in both 2 and 4 ohm and after checking the seriel number, it is the 2 ohm.

Now i feel like an idiot. I assume this changes what everyone has said already.

Sorry guys:redbrick:

 

[Offroader5]

Well in that case...you can run the amp in 4 ohm mono and wire your voice coils in series like I mentioned at first. Running two 2 ohm coils in series will give you 4 ohms.