Amp output I have 3 type-R 12" subs. They are the 4 + 4 versions, so the coils are in series and then each sub paralleled for a 2.67 ohm load. They are hooked up to a MRD-M1000 amp. IS there anything wrong with this setup? I was unpleasantly suprised with the output of this system. Also...during a road trip the system gets noticably louder after about 2 hrs. -Thanks.

You can't bridge that amp onto a load lower than 4 ohms. So you can't bridge that amp onto two 4 ohm subs. To get the most power out of your subs is easy. Run one channel to one sub and the other channel to the other sub. 165 watts RMS is plenty for most subs.

The ohms rating measures the electrical resistance of the subs(impedance). On the subs there is usually a label that tells you what the impedance is for that particular sub,example= 4 ohms . The only way you can get to a 1 ohm load or less with a pair of tens is if each sub has dual voice coils that are 4 ohms each wired in parallel. Generally Sony xplod's are a single coil 4 ohm woofer-yours might be the exception in this case .To figure out your resistance say with 2 subs that are 4 ohms you have to know how you intend to wire them for instance if your amp puts out a fair amount of power @2 ohms and thats the number you want to hit than you will want to wire the subs in parallel( + to + and - to -) wiring in parallel lowers the resistance.(ohms) If you want to hit 1 ohm and you have dual 4 ohm coils then wire all 4 coils in parallel and that will then be a 1 ohm load. Its simply a matter of dividing the ohms by the number of speakers that you intend to connect. if you had 3 10s that were 4 ohms each and you wired them in parallel the ohms would be 1.33 (as 4 divided by 3 is 1.33)(4 divided by 2 is 2) (4 divided by 4 is 1) On the flip side wiring in series will raise your impedance-a pair of 4 ohm subs wired in series gives you an 8 ohm load 3 subs gives you 12 ohms and so on. I wouldnt worry about the high current switch unless youre planning on taking it down below 1 ohm which it sounds like you arent currently set up for.

You need to wire them according to the limitations of your amp you can pull a 1 ohm overall load just by connecting all of your coils in parallel- or you can get an overall load of 4 ohms by wiring each sub individually in a series configuration which will yield a 12 ohm load per sub -and then wire the 3 sets in parallel which will bring your ohms back down to 4. You can do a lot with that many coils it depends on your amp really-ideally a 1 ohm stable class d mono amp that is 1000-1500 watts rms would knock the **** outta those things JL is the good stuff.

That's dependent on your subwoofers. You will need 2 dual 4 ohm subs wired in Parallel, a single dual 2 ohm subwoofer wired in parallel, a single dual .5 ohm wired in series. Or something similar.

http://www.bcae1.com/spkrmlti.htm

+ on amp output to + on speaker #1 to + on speaker #2. - on amp output to - on speaker #1 to - on speaker #2. This is a parallel circuit....4 ohms in parallel with 4 ohms = 2 ohms. IF it were wired in series....would represent 8 ohm load.

Hello mikey4569mky,

Unless your amp is stable below 1 ohm, there's really only one wiring solution. And that is to series the voice coils making each sub 8 ohms, then parallel all 3 subs to the amp for a 2.67 ohm load. If you parallel the voice coils and then parallel the subs, the impedance will be 0.67 ohms, much too low for most amps.

You could parallel the voice coils and then series the subs for a 6 ohm load, but the amp won't put as many watts into a 6 ohm load. Most are optimized for 4 ohms or 2 ohms. And it's not good to run subs in series anyway.

Here's the wiring diagram.

Hope this helps.

Hello smoot_dog,

Well, you did not specify whether you have the 2 ohm or the 4 ohm versions of the L7 and that will impact your choice of amps. But with 8 voice coils and 4 subs to work with, you certainly have lots or potential configurations.

If your subs are the 4-ohm version, I would recommend the Alpine MRP-M1000. Currently it is on sale at www.crutchfield.com for $347.00. With this amp you'd wire the voice coils in parallel (2 ohms), wire each of the 2 pair of subs in series (4 ohms), and the resulting pairs parallel to the amp for a final load of 2 ohms.

If your subs are the 2-ohm version, I would recommend the Rockford-Fosgate Punch P1000-1bd which is stable at 1 ohm. Crutchfield sells it for $349.99. With the Punch and 2-ohm voice coils, you'd series the voice coils (4 ohms), parallel each pair of subs (2 ohms), and then parallel the resulting pairs to the amp for a final load of 1 ohm.

Either of these amps will provide an honest 250 watts RMS to each L7. They'll not only rock your vehicle, they'll rock the pavement.

Sounds like the two subs wired together might be too much of a load on the amp and it is shutting off. Try wiring the two subs in series. That will reduce the load on the amp but will conversely put out less power. Less is better than none though. In any case check your amp to see what the lowest ohm rating it can see, that ohm rating is where you want your subs and if faced with a choice of either going under (lower numerically) or over (higher numerically) GO OVER!-it is much safer.
Here's an article I wrote that can help explain how to wire the subs to the amp.

OHM LOADS, SUB WIRING, OHM RELATED POWER OUTPUT

SERIES SUBWOOFER WIRING
Wire the positive pole from one voice coil (using wire that is as thick or thicker than your wire from amp to sub) to the negative pole of the other voice coil (on the same sub). This will leave you with a positive pole from one voice coil and a negative pole from the other giving you the two leads that will be hooked up to the amplifier or other subs. When wiring in series, the ohms will go up numerically, and the load on the amp will go down. Almost all amplifiers power output will follow this rule, except some amps such as JL Audio's “Ohm matching” D Class amps.

PARALLEL SUBWOOFER WIRING
Wire the positive pole from one voice coil (using wire that is as thick or thicker than your wire from amp to sub) to the positive pole of the other voice coil (on the same sub). Then wire the negative to the negative in the same way. You can then wire to the amp or other subs. When wiring in parallel the ohms will go down numerically, and the load on the amp will go up. Almost all amplifiers power output will follow this rule, except some amps such as JL Audio's “Ohm matching” D Class amps.

MULTIPLE SUBS USING SERIES AND PARALLEL WIRING
In order to match your amplifiers ohm rating you can use parallel and series wiring together, just keep things even for power distribution and to avoid phase issues.
Example: I have two “Type X 12” subs” that have dual 2ohm voice coils and have to match my “Amplifier X” ohm rating of 2ohms mono. In this case, I would wire each subwoofer in series (giving me a 4ohm load), and then wire the two subs in parallel to get my 2ohm mono load. When wiring multiple subs just, treat each sub as a voice coil and wire accordingly.

POWER OUTPUT AND OHM LOADS
For example if “Amplifier X” can make 100watts@8ohms, it would make 200watts@4ohms and 400watts@2ohms. However with every drop in ohms the amplifier is put under more pressure. It starts to create a lot of heat, distortion figures begin to climb, damping rates drop, and some amps even throw power spikes when clipping. SO BE SURE TO CHECK YOUR AMPS RATING AND DO NOT EXCEED IT!

-Dynami

You can connect them in a series/parallel configuration. Put two of them in series and then connect the last one in parallel across the two in series. This would give you an impeadance of around 2.7 ohms. Only do this if your amp is stable at 3 ohms or less. I am not familiar with the specs of your amp. If your amp is only 4 ohm stable you can not do this.
This would also give you half the power on the two subs in series as the power for the one that is parallel. The two in series would be sharing the total output signal, where-as the one in parallel would get the entire output signal from the amp.
if you were to connect a fourth sub woofer in this configuration it could give you a 4 ohm load, by adding the fourth sub in series with the single sub that is in parallel. or in other words, yu have two sets of 2 sub woofers each in series. That gives you two 8 ohm loads (two 4 ohm subs in series is 8 ohms). Then you take the two sets of subs and parallel them (two 8 ohm loads in parallel equals 4 ohms).

If i had a picture to show you it would make sense, two subs in series that are in parallel with two subs in series.

The easiest way to think of wiring voice coils and subs is this:

• Two items of the same impedance in parallel = Half of the impedance
• 4 ohms in parallel with 4 ohms = 2 ohms
• 8 ohms in parallel with 8 ohms = 4 ohms
• Two items of the same impedance in series = Double the impedance
• 4 ohms in series with 4 ohms = 8 ohms
• 8 ohms in series with 8 ohms = 16 ohms

In this case, you want to wire two subs, each with dual 4 ohms voice coils, so that the total equals 2 ohms. Your options are:

• DVCs in parallel, 2 subs in series = 4 ohms
• DVCs in series, 2 subs in parallel = 4 ohms
• DVCs in parallel, 1 sub = 2 ohms

With two, dual 4 ohm subs, you can only have 1 ohm or 4 ohm total impedance.