Im looking at buying a set of JL audio 10W3 subwoofers, they come in 2 ohm, 4 ohm, and 8 ohm. How do I know what I want and what do you base your desision around?

you base it off of the amp that you are going to be running you will need a 2ohm stable amp. which these days i think most are. if you bridge the amp then you take the ohms of the subs and cut that in have. so if you have 2 8 ohm subs bridged then you are only running 4 ohm. so if you wanted to get the 2ohm subs and bridge them then you would need a 1ohm stable amp

I was thinking about a JL amp, maybe the 500/1 or 1000/1. Im not sure if they are a good choice or not.

If you're only gonna be Running 2 10's, the 500/1 will be enough. The 1000/1 will Kill them in no Time.

So what ohm do I want?

Get the 4ohm Versions.

If you're only gonna be Running 2 10's, the 500/1 will be enough. The 1000/1 will Kill them in no Time.

He's right on that...

I would get the 2ohm versions and wire them in series so each speaker receives the same amount of current. Doing it this way would also give the amp a 4ohm mono load which will make the amp much happier since that is what they are built to drive.

I would get the 2ohm versions and wire them in series so each speaker receives the same amount of current. Doing it this way would also give the amp a 4ohm mono load which will make the amp much happier since that is what they are built to drive.

Agreed. Since you are looking at the mono amps you won't have to worry about the ohms drop from bridging anything. Here's the diagram on how to hook it up.

http://akamaipix.crutchfield.com/ca/learningcenter/car/subwoofer_wiring/2SVC_2-ohm_mono.jpg

JL Amps put out the Same Power from 1.5-4ohms.

So VC Impedance or Config. isn't gonna matter, as long as your Final Load is between 1.5-4ohms.

So VC Impedance or Config. isn't gonna matter, as long as your Final Load is between 1.5-4ohms.

It is going to matter. The amp is designed to run a 4ohm load. Even though it can handle a 2ohm, 1ohm, or even .5ohm load doesn't mean the amp is going to like it. Remember the lower the impedance number the closer you are to a short circuit. If he runs it at a 2 ohm load for an extended period of time or possibly a short period of time at a loud volume level the amp can overheat and go into protection mode.

Noooo, do your research BEFORE you start giving out False Information.

http://mobile.jlaudio.com/products_amps.php?amp_id=439 They wouldn't have it say: "500 W RMS @ 1.5 ohm - 4 ohm (11V-14.5V)" if it didn't Output the SAME Power at any Impedance in that Range.

Here's some more Reading about how the R.I.P.S System Works - http://mobile.jlaudio.com/products_amps_pages.php?page_id=228

Noooo, do your research BEFORE you start giving out False Information.

Show me where I gave out false information. I never said it wouldn't give the same amount of power. You need to first learn about basic electronics and reread my post.

It is going to matter. The amp is designed to run a 4ohm load. Even though it can handle a 2ohm, 1ohm, or even .5ohm load doesn't mean the amp is going to like it. Remember the lower the impedance number the closer you are to a short circuit. If he runs it at a 2 ohm load for an extended period of time or possibly a short period of time at a loud volume level the amp can overheat and go into protection mode.


Any of the JL slash series amps are DESIGNED to handle 1.5 to 4 ohms. the amp will not overheat, and will function just fine. I do agree with you that on many amplifiers your statement is true, but on the JL series in question it is not so. The fact you are not familiar with this perticular series is not your fault. The way Mad Maxx replied wasnt the best way to handle it, but he is correct. Check into the JL amps, i think you will like what you see.

Show me where I gave out false information. I never said it wouldn't give the same amount of power. You need to first learn about basic electronics and reread my post.

Right here man: It is going to matter. The amp is designed to run a 4ohm load. Even though it can handle a 2ohm, 1ohm, or even .5ohm load doesn't mean the amp is going to like it. Remember the lower the impedance number the closer you are to a short circuit. If he runs it at a 2 ohm load for an extended period of time or possibly a short period of time at a loud volume level the amp can overheat and go into protection mode.

You said the Amp is Designed to Run at a 4ohm Load, and if he Runs at a 2ohm Load for too long, the Amp will Overheat and go into Protect.

That, is False Info.

The Amp is Designed to Run at 1.5-4ohms for as long as it wants to and the R.I.P.S will Adjust everything Inside so it'll all work Perfectly and not Overheat or go into Protect.

Here is an Excerpt FROM the PAge about how R.I.P.S works, because it's Obvious you didn't Read anything - Conventional amplifiers are designed to produce optimum power at a particular impedance (2 ohm, for example). When asked to run above that impedance (say, 4 ohm), these amplifiers lose power (half their power from 2 ohm to 4 ohm). This will not happen with a JL Audio Slash v2 amplifier because the R.I.P.S. System detects the actual impedance being driven and adjusts output rail voltages to deliver optimum output. The entire process is seamless, automatic, and results in incredible dynamics for satellite channels and consistent power output for a wide range of subwoofer configurations. It also takes into account the real impedance of the system, rather than relying on often inaccurate assumptions based on a speaker's rated impedance.
The bottom line of the R.I.P.S. system is: Optimum power, at any impedance between 1.5 ohm and 4 ohm per channel, at any vehicle voltage between 11V and 14.5V.

I've been Installing for 15 Years, and I'm not some High School Kid that works at Best Buy as an Installer and doesn't know my Ass from my Elbow. When I'm not working at my own Shop, I fill in at a Shop that's one of the Top 10 on the East Coast since '03. So I'm a lil more Qualified than most in the Field of Car Audio. :D

So I should buy the 4 ohm versions? Im going to run the 500/1 amp. I will run a second amp for the rest of the speakers in my doors. I'm not sure about what speakers I will get for up front, maybe JL? Any suggestions on an amp for the 4 door speakers? I like the JL Audio suff.

The 4 ohm coils in parallel will give you a 2 ohm load, that will work fine. For your doors, JL makes the 300/4. I had one of each but never installed them in the truck. The 300/4 is 75w per channel IIRC. As far as door speakers, Listen to a bunch of speakers, and pick what sounds good.

i like JL stuff, they make a good subwoofer. as for the ohms, i dont know too much about subject but i had a 10w3 at 4 ohms at it hit pretty hard.

If he runs it at a 2 ohm load for an extended period of time or possibly a short period of time at a loud volume level the amp can overheat and go into protection mode.
You said the Amp is Designed to Run at a 4ohm Load, and if he Runs at a 2ohm Load for too long, the Amp will Overheat and go into Protect.


You misquoted what I said. There is a big difference between "can" and "will". BTW, I did read what JL Audio says about their RIPS technology. And for someone who is such a guru and has a vast experience in car audio I would expect you to understand how a regulated power supply works. All it's doing is regulating the power. It is in no way changing the impedance. Most amps of any quality can handle a 2ohm mono load no problem and I know JL's stuff is decent quality. Notice they do not state that it can handle a 1ohm or .5ohm load without issues. That's because the amp does not regulate impedance!!
So yes, this amp can handle a 2ohm mono load as will most amps and I never said it couldn't. What I did say is it's designed to run at a 4ohm load. And guess what? Low and behold, it is!! Read the specs on it.
THD at Rated Power: <0.05% @ 4 ohm
I wonder why JL chose a 4ohm load to run their tests? Hmmm. Maybe because they received the least amount of distortion at this load since the amp is designed to run at this load?
Damping Factor: >500 @ 4 ohm / 50 Hz
>250 @ 2 ohm / 50 Hz
I wonder why the damping factor @ 2ohm is only half of it's rating at 4ohm? Because the amp is designed to run at 4ohm. Period.

So, to sum all this up the above just proves that I gave solid advice on which speakers to buy. There is no reason to run a 2ohm load since this amp regulates the power output. Some amps will give more power by dropping the impedance in half. Not so in this case so there is no benefit to running a 2ohm load. But there is a benefit to running a 4ohm load. Cleaner signal and more power reaching the subs.

Still need more proof? Okay, fine. Let's do a little math here.
Amp is rated at 500 watts. Let's just say he uses 5' of 12awg speaker wire to power the subs which are showing a 4 ohm load to the amp.
The amp has a damping factor of 500 @ 4ohms. Do the math since I know you know how to with 15 years experience and working at 2 shops and you'll see this equates to a new damping factor due to the speaker wire of 167.36. The amp will have an output voltage of 44.72 @ 11.14 amps. Due to the voltage loss of the wire this setup will give 495.95 watts to the speakers.
Now lets do it with the same wire but the subs showing a 2ohm load to the amp giving the amp a damping factor of 250. This setup gives a damping factor of 83.68. The amp will have an output voltage of 31.62 @ 15.69 amps. Due to the voltage loss of the wire this setup will give 492.04 watts to the speakers.
Big difference? No. Is it even an audible difference? No. But this just proves once again that I did give solid advice on which setup would be best.
One last thing, before you fall back on your crutch of "JL uses the RIPS technology so there can't be any difference!", if there wasn't a difference in output voltage the damping factors for 1.5-4ohms would all be the same. All it's doing is regulating the input voltage so the amp will play just as loud when the car is off as it is when the car is on.

So the 2 ohm in series is the way to go?

So the 2 ohm in series is the way to go?

See post #19 and actually read it. That guy knows what's up.

I read it all and I agree totally

I (as you see in the nick) installed (past tense) car stereo and alarms, the Ohm load will depend on the number of coils, Some are DVC (Duel Voice Coil) and some are SVC (Single Voice Coil). If you are running 2 speakers keep them the same and don't mix the Ohm per speaker. Each coil drops the Ohm load in half when wired in parallel seen by the amp. What this means is, If you have a DVC 4 Ohm speaker (size is not relevant) the amp will see 2 Ohms when the coils are wired in parallel. Most amps will handel this without a issue, I have a hi current Autotek amp that is 1/4 Ohm stable so i run without issue my 2 12's that are 4 ohm DVC, now when you bridge the speakers you are the positive side of the sign wave on one channel of the amp and the negative on the other side. hence you will be seeing the total output of the amp

So the 2 ohm in series is the way to go?

See post #8. Be sure to understand the difference between parallel wiring and series wiring if you don't already.

hey guys i learned something reading through this thread thanks underPSI :)

I understand the difference in parallel and series but I dont know a whole lot about the rest.