8 Ohm or 2 Ohm for SQ Build

[budgetkiller 10+ year member]

Hi everybody,

I just picked up a pair of JL 13W3V3 subwoofers (4 Ohm version). I plan to run them off a JL Slash series 1000/1v2. I'm going for strict SQ with this build and my wiring options are 2 ohms (the amp is rated 1000w @ 1.5-4 ohms) or 8 ohms for approximately 500w. I plan to run the woofers in a sealed enclosure built to spec.

Again, I'm going for strictly SQ here. I bought a 1000/1 so I could have more power than I should ever need and plenty of clean overhead. That being said, I'm leaning towards wiring the subs to 8 ohms. 500w on 2 13.5" drivers should be more than enough bass (currently running a single SA12 ported @ 4 Ohms). I know that with higher impedence the damping factor on the amp increases which from what I understand marginally improves sound quality. However, lets say I'm listening to music using about 80% of the amp's max clean output. Since the amp is running 80%, and in turn would only be running at 40% percent if I wired it to two ohms, will the extra strain on the amp make up for any marginal increase in sq that the higher impedence would give me?

My second question is, is running a JL Slash series amplifier at 8 Ohms a bad idea? I know for most amplifiers it's no issue, but the JL has that special regulated power supply and is only spec'd from 1.5-4 Ohms. I'm just not sure if 8 Ohms would mess with it or not.

Sorry for the long post, I wasn't sure how to phrase my questions. Thanks in advance for the input!

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[garychoffmann 10+ year member]

2 ohm should suit you well

 

[Jeffdachef 5,000+ posts]

Ohm load only measures how much power the sub is receiving. There's a thing called box rise too, if you wire to 2 ohms, you'll be around 4-5 ohms after rise and wiring to 8 ohms will land you in the 10 ohm range. A sub that is underpowered will sound sloppy.

Since its a good amp, you can use the Digital Multi meter method to tune your amp. Google it up. Pretty much by using the gain knob you can limit how much power the amp actually puts out so if you have 1000 watts, you can set it so it only sees 500. The amp will be working less hard and the subs will be fully powered.

 

[budgetkiller 10+ year member]

2 ohm should suit you well

Thanks! Ideally I would have stuck with 4 Ohms but I stumbled across a deal on these so I jumped on it. Do you know if 8 Ohms would hurt the amp? I could always just try wiring it both ways.

 

[budgetkiller 10+ year member]

Ohm load only measures how much power the sub is receiving. There's a thing called box rise too, if you wire to 2 ohms, you'll be around 4-5 ohms after rise and wiring to 8 ohms will land you in the 10 ohm range. A sub that is underpowered will sound sloppy.
Since its a good amp, you can use the Digital Multi meter method to tune your amp. Google it up. Pretty much by using the gain knob you can limit how much power the amp actually puts out so if you have 1000 watts, you can set it so it only sees 500. The amp will be working less hard and the subs will be fully powered.

Wow. Exactly what I wanted to know. Looks like I will be running two ohms then. Thanks for the help!

 

[DDFusion]

Ohm load only measures how much power the sub is receiving. There's a thing called box rise too, if you wire to 2 ohms, you'll be around 4-5 ohms after rise and wiring to 8 ohms will land you in the 10 ohm range. A sub that is underpowered will sound sloppy.
Since its a good amp, you can use the Digital Multi meter method to tune your amp. Google it up. Pretty much by using the gain knob you can limit how much power the amp actually puts out so if you have 1000 watts, you can set it so it only sees 500. The amp will be working less hard and the subs will be fully powered.

Please do not take any advice from this idiot.

 

[Jeffdachef 5,000+ posts]

Please do not take any advice from this idiot.

Comming from a noob troll that has no idea what the fk car audio is. Just a plague on the forum bashing and disliking everyone and their grandmas.

 

[UGHH]

OP, Jeff knows what he's talking about. This Blake guy is a troll. Like Jeff said all he does is talk ****, and sometimes he's too lazy to do that and he'll just "dislike" everybody's posts.

 

[LosIsATool 5,000+ posts]

Wow. Exactly what I wanted to know. Looks like I will be running two ohms then. Thanks for the help!

Those amps are not effected by the rise Jeff mentioned.

Lower loads do hinder SQ but they will have a benifit if you are not using all the power its capable of. You will have headroom and that makes it more dynamic. It's a good trade off.

Now in your case with the Slash 1000 you could wire at 1.5 to 4 and be the same but 1.5 will lower efficency. If you are not planning on using everything it has it will be fine. If you are using it all I hope you have $500 set aside to replace your alternator. Being able to do what they do comes at a cost. They will **** every bit of power you have all the time.

 

[budgetkiller 10+ year member]

Those amps are not effected by the rise Jeff mentioned.Lower loads do hinder SQ but they will have a benifit if you are not using all the power its capable of. You will have headroom and that makes it more dynamic. It's a good trade off.

Now in your case with the Slash 1000 you could wire at 1.5 to 4 and be the same but 1.5 will lower efficency. If you are not planning on using everything it has it will be fine. If you are using it all I hope you have $500 set aside to replace your alternator. Being able to do what they do comes at a cost. They will **** every bit of power you have all the time.

Thanks. I already invested in a digital volt meter so I can keep an eye on things. I back off if I start seeing significant drop because you're absolutely right; that amp has no problem dipping my electrical to low 13s with the twist of my wrist. I also just installed a Diehard Platinum battery under the hood. Big three coming when I get the chance. Part of the reason I'm happy to switch to two 13.5"s from my single 12 is that I don't think I will be drawing so much current at the same listening level which is great, because this is just my substage. I have plans to go 4-way active.

 

[LosIsATool 5,000+ posts]

Thanks. I already invested in a digital volt meter so I can keep an eye on things. I back off if I start seeing significant drop because you're absolutely right; that amp has no problem dipping my electrical to low 13s with the twist of my wrist. I also just installed a Diehard Platinum battery under the hood. Big three coming when I get the chance. Part of the reason I'm happy to switch to two 13.5"s from my single 12 is that I don't think I will be drawing so much current at the same listening level which is great, because this is just my substage. I have plans to go 4-way active.

I'm a huge fan of slash amps. They are expensive but worth every penny if you understand what they are capable of. I ran a 3 way active in the last car with the 450/4 and 300/2. SQ was top notch and power was always on. Having high end front stage was helpful. Nobody believed a simple 3 way front stage blended perfectly with a 150db sub stage.

 

[gckless 5,000+ posts]

Ohm load only measures how much power the sub is receiving. There's a thing called box rise too, if you wire to 2 ohms, you'll be around 4-5 ohms after rise and wiring to 8 ohms will land you in the 10 ohm range. A sub that is underpowered will sound sloppy.
Since its a good amp, you can use the Digital Multi meter method to tune your amp. Google it up. Pretty much by using the gain knob you can limit how much power the amp actually puts out so if you have 1000 watts, you can set it so it only sees 500. The amp will be working less hard and the subs will be fully powered.

So we're talking about SQ and music and you're talking about rise?

Ohm load is a measure of resistance.

Underpowered does not equal "sloppy".

OP, I think you will absolutely fine at 2ohms. The difference in a front stage from 2ohms to 8ohms is pretty apparent, but unless you have heard a lot more SQ setups that what you came from (those SA's) I doubt you would hear a difference in the two wiring choices for your subs. You'd benefit more from the extra power. Thos amps are good, you'll be happy with them. Headroom is a really good thing too. You can set with the DMM method here and be fine for the most part.

 

[budgetkiller 10+ year member]

I'm a huge fan of slash amps. They are expensive but worth every penny if you understand what they are capable of. I ran a 3 way active in the last car with the 450/4 and 300/2. SQ was top notch and power was always on. Having high end front stage was helpful. Nobody believed a simple 3 way front stage blended perfectly with a 150db sub stage.

I'm definitely still learning. I had a Rockford T500-1BD before this amp and the SQ difference between 1 and 4 Ohms was night and day. It really woke me up to factors like impedance making or breaking (sometimes literally) a system. I only have a Slash amp for the substage, but it's definitely the nicest sub amp I've ever owned. I can't wait to run it off a line driver (I read somewhere that it plays more dynamic that way). I have a pair of old school PG amps for the front stage. I'm a college kid so this system has to have a budget. The Slash amp was a splurge.

 

[budgetkiller 10+ year member]

So we're talking about SQ and music and you're talking about rise?Ohm load is a measure of resistance.

Underpowered does not equal "sloppy".

OP, I think you will absolutely fine at 2ohms. The difference in a front stage from 2ohms to 8ohms is pretty apparent, but unless you have heard a lot more SQ setups that what you came from (those SA's) I doubt you would hear a difference in the two wiring choices for your subs. You'd benefit more from the extra power. Thos amps are good, you'll be happy with them. Headroom is a really good thing too. You can set with the DMM method here and be fine for the most part.

That's good to hear. I was worried the SQ increase would be marginal since I'm going from a single 12" @ 4Ohms to a pair of 13.5"s @ 2Ohms. I'm glad to hear that that should not be the case (I'm guessing that going from ported to sealed will pretty much assure that). The main reason I was considering 8 Ohms is that even with half the power I suspect I will still have some overhead. Even with 1 12 I rarely come anywhere near the full potential of this amp. With will over twice the cone area, I suspect that 500w will be more than enough for the vast majority of my listening habits which is why I was considering 8 Ohms. An easy marginal increase is a great thing when we're talking SQ.

 

[LosIsATool 5,000+ posts]

Why are you not going ported? That myth about sealed having better SQ is a myth. Most who think that have only used or heard prefabs