tbone4590

i'm planning to use jl audio 2 12w3v3 subwoofers
they come in single voice coil 2 or 4 ohm
the amplifier of choice is an alpine mrx m110 specs are 650w at 4 ohm and 1100 at 2 ohm
my preference is to run as high of resistance as possible while retaining enough power output, for the best of both worlds of sq/spl would i be best of running the 2ohm versions in series to the amp pushing me up to 4ohms. 4ohm subs running in series up to 8 ohm final, not sure if i'd have enough power or how the amp would handle doing so, if i'm better off using different subs with that amp or a different amp to match with the subs better, if my idea to run the 2ohm versions in series to push up to a final of 4ohms in a dual box chambered separately can someone draw a rough diagram of the best way to wire it correctly and most efficiently. thank you in advance for anyone willing to help.

lexus997

From what you typed, your bias is:
* 4 Ohm load on the power amplifier
* Two subwoofers
* dual chamber enclosure


Wire the two drivers in series.

tbone4590

thanks for your response, the pic is great i'll just drill a hole in between and reseal the hole, what would you suggest as a strong sealant for the wire between the chambers and the wires exiting the enclosure, my last concern is if i'm running the 2 ohm subs is there a chance something could happen to one subwoofer causing the other to run at 2 ohms and push the 1100w and more than likely destroy it as well.

lexus997

I would just seal any holes that wire goes through with silicone. However, you should give the silicone a day or two to completely cure before installing your subwoofers.

You may want to install a speaker terminal cup in each chamber. This gives you more flexibility as then you can connect the two drivers independently, in parallel or in series. The attached image should show a series connection as you have previously stated is your bias.


If one of the drivers fails, it should most likely create an open circuit which would be the same as one of the wires from the amplifier being cut. Thus, no worries about over driving the amplifier.

herefore

yes,you should give the silicone a day or two to completely cure before installing your subwoofers.

aj289

That's the way you want to do it. That way, in the future, you can use the same box if you ever need to upgrade, replace or change wiring configurations. Having one terminal per chamber gives you that flexibility.

650W RMS is a LOT of power. Two 12" subs at 650W RMS is pretty nuts and should hit hard and clean.

I remember running one JL W6 and an Alpine V12 back in the day. I think it was something like 300W RMS bridged and I was setting off car alarms. Now the equipment is more efficient. That should be a nice setup.

tbone4590

yah my most recent system was the alpine type r that was "500"w rms and i was running 900 to it with a hifonics that i'm not overly impressed with, i felt like it put out a crappy signal, but once i rebuilt the box because i realized i messed up the port really bad, it hit pretty damn hard. honestly with some songs it was right about the level of bass i love but others it was lacking a little bit and i built the box for slightly too low of frequency i think, because it had a hard time hitting hitting notes but i'm still learning. thanks for the input. I've learned i don't know nearly as much as i thought.

tbone4590

another question, i used to think that you would want the wire between the two subs to match the length ofthe wires going from the amp to the sub as well as equal length wires from each sub to the amp for balance why is that not the case?

aj289

Well, your subs just have a long coil of wire (or two for DVC) wound up on a moving tube within the magnet. Without getting into some Ohm's law discussions, as long as you use quality speaker cable over short distances, the resistance of the speaker wire is negligible compared to the resistance of the speaker coils so having matching lengths for wires doesn't really matter.

I'm assuming you will use quality, heavy gauge speaker cable since you seem to know quality products. So with your setup, it is essentially two resistors in series with near perfect conductors connecting them over short runs. Simple as that. No need to match the lengths at all.

aj289

Enclosure design is critical for any speaker, and especially with subs. Speaker manufactures include design parameters for the recommended enclosure sizes; sealed, ported, bandpass.

I once built a JBL GTO 12" sub in a bandpass box exactly per JBL specs. No pretty viewing window or anything... Just a carpeted box with a flared port and dropped it in my friend's jetta.

275W RMS and at certain frequencies, his hair would move and his steering wheel would shake. It was incredible.

If you're buying an off the shelf box and you do any DIY, at least try to match the dimensions in the manufacturer specs and get the port length size and diameter right. Or, buy the box from the manufacturer that is designed for the sub. It makes a big difference.

tbone4590

thanks for the good info on the wiring and the coils, i've definitely learned my lesson with enclosures and how big of a difference they make, i had a crappy ported prefab box for two 10" type r's in an extra cab f150 and i didnt hit as hard as the one type r did in the box i made. made me regret selling one of the subs i cant imagine how it would have been with two of them in box's like i made, would have been pretty awesome. i'm hoping this set up blows me away.