Subwoofer Ohms?
03-23-2005, 12:18 AM
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Subwoofer Ohms? I'm looking to put a JL Audio 10w3v2 in a stealth box and power it with a JL Audio 250/1 amp. This is all going to a Pioneer HU with pre-amp outputs. I noticed that the sub has Dual 2 ohm, Dual 4 ohm, and Dual 6 ohm configurations. I'm wondering what's the difference between the configs and which would be best for me.
Thanks in advance.
Thanks in advance.
03-23-2005, 12:39 AM
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Dual coil subs are more flexible that single....you can wire the two coils in series or parallel, making the sub either half or twice the impedance listed. Or, for really high powered stuff, people will run each coil off it's own amp. Make sure you match the effective ohm load of the sub with the amp. If you go too low, the amp can overheat and go into protect or fry, if you go higher than recommended you won't get as much power.
Effective loads:
Type / Series / Parallel
Dual 2 / 4 ohm / 1 ohm
Dual 4 / 8 ohm / 2 ohm
Dual 6 / 12 ohm / 3 ohm
What are the power ratings on the amp?
Some other things to consider....if you run two subs, you can series or parallel them also, doubling or halving the effective load above depending on how you do it. If you get a 2 channel amp and bridge the two channels for the subs, you're splitting the ohm load between the two channels.
For example, say you have a 2 ohm stable mono amp. You could configure it as follows:
-Two dual 2 ohm subs. Wire the coils in series to give you one 4 ohm load, then wire the two subs in parallel to give you a 2 ohm load on the amp.
-One dual 4 ohm sub. Wire the coils in parallel, making a 2 ohm load.
If you had a two channel 2 ohm stable amp and were bridging the channels, you could do it like this:
-Two dual 4 ohm subs. Wire the coils in series to give you 8 ohms per sub, then parallel the subs on the amp to get 4 ohms. Divide the 4 ohms by the two channels, and you get 2 ohms per channel.
-One dual 2 ohm sub. Wire the coils in series to get 4 ohms, then bridge the channels and divide by two to get 2 ohms per channel.
I hope this helps....let me know if you have more questions.
Effective loads:
Type / Series / Parallel
Dual 2 / 4 ohm / 1 ohm
Dual 4 / 8 ohm / 2 ohm
Dual 6 / 12 ohm / 3 ohm
What are the power ratings on the amp?
Some other things to consider....if you run two subs, you can series or parallel them also, doubling or halving the effective load above depending on how you do it. If you get a 2 channel amp and bridge the two channels for the subs, you're splitting the ohm load between the two channels.
For example, say you have a 2 ohm stable mono amp. You could configure it as follows:
-Two dual 2 ohm subs. Wire the coils in series to give you one 4 ohm load, then wire the two subs in parallel to give you a 2 ohm load on the amp.
-One dual 4 ohm sub. Wire the coils in parallel, making a 2 ohm load.
If you had a two channel 2 ohm stable amp and were bridging the channels, you could do it like this:
-Two dual 4 ohm subs. Wire the coils in series to give you 8 ohms per sub, then parallel the subs on the amp to get 4 ohms. Divide the 4 ohms by the two channels, and you get 2 ohms per channel.
-One dual 2 ohm sub. Wire the coils in series to get 4 ohms, then bridge the channels and divide by two to get 2 ohms per channel.
I hope this helps....let me know if you have more questions.
Last edited by thunder550; 03-23-2005 at 12:50 AM.
03-23-2005, 01:08 AM
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Here's the Sub Specs
Nominal Diameter: 10 inches (250 mm)
Continuous Power Handling: 300 Watts
Voice Coil: 2.25" diameter, 4-layer, Kapton former
Available Configurations: Dual 2 ohm, Dual 4 ohm or Dual 6 ohm
Xmax (one-way, linear): 0.51"-0.58" (13.0-14.7 mm) depending on specific model
Sealed Enclosure Range: 0.60-0.90 cu.ft. (17.0-25.5 liters)
Ported Enclosure Range: 1.00-1.50 cu.ft. (28.3-42.0 liters)
VRC™ Technology: YES
Elevated Frame Technology: YES
Here's the Amp specs
Rated Power:
250 W RMS @ 1.5 ohm-4 ohm (11V-14.5V)
THD at Rated Power:
<0.05% @ 4 ohm
S/N Ratio*:
>95dB below rated power
Frequency Response:
5 Hz - 500 Hz (+0, -1dB)
Damping Factor:
>500 @ 4 ohm/50 Hz
Input Range:
switchable from 200mV-2V RMS
to 800mV-8V RMS
Dimensions:
10.25"L x 9.25"W x 2.36"H
Nominal Diameter: 10 inches (250 mm)
Continuous Power Handling: 300 Watts
Voice Coil: 2.25" diameter, 4-layer, Kapton former
Available Configurations: Dual 2 ohm, Dual 4 ohm or Dual 6 ohm
Xmax (one-way, linear): 0.51"-0.58" (13.0-14.7 mm) depending on specific model
Sealed Enclosure Range: 0.60-0.90 cu.ft. (17.0-25.5 liters)
Ported Enclosure Range: 1.00-1.50 cu.ft. (28.3-42.0 liters)
VRC™ Technology: YES
Elevated Frame Technology: YES
Here's the Amp specs
Rated Power:
250 W RMS @ 1.5 ohm-4 ohm (11V-14.5V)
THD at Rated Power:
<0.05% @ 4 ohm
S/N Ratio*:
>95dB below rated power
Frequency Response:
5 Hz - 500 Hz (+0, -1dB)
Damping Factor:
>500 @ 4 ohm/50 Hz
Input Range:
switchable from 200mV-2V RMS
to 800mV-8V RMS
Dimensions:
10.25"L x 9.25"W x 2.36"H
03-23-2005, 09:29 AM
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Ok...if it's a mono amp and you're stuck on that one, the best would be for you to get the dual 4 ohm sub and wire the coils in parallel. The amp would not be putting out it's best amount of power, and even if it was, it would not be at the power rating for the sub. Read this post (https://ls1tech.com/forums/wiring-stereo-electronics/294306-subwoofer-question.html) about why I think you should go with an amp that can at least match the rated power of the sub, if not exceed it. If you do end up getting the ones listed, then yeah, the dual 4 ohm sub would be best.
03-23-2005, 09:59 AM
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OK so I think i understand, but probably not. I found this on JL Audio's website.
"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."
So this seems to mean that the amp has 250w RMS power no matter how many ohms the sub is running(between 1.5 and 4ohms). So with a parallel wired dual 4 ohm sub (which would actually run at 2 ohms right?) the amp would run at 250w and the sun would run at 300w both at 2 ohms. This would underpower the sub by like 50w right?
Should I look into getting a 500w mono sub, the next level up?
"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."
So this seems to mean that the amp has 250w RMS power no matter how many ohms the sub is running(between 1.5 and 4ohms). So with a parallel wired dual 4 ohm sub (which would actually run at 2 ohms right?) the amp would run at 250w and the sun would run at 300w both at 2 ohms. This would underpower the sub by like 50w right?
Should I look into getting a 500w mono sub, the next level up?
03-23-2005, 10:42 AM
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Originally Posted by kraut187
OK so I think i understand, but probably not. I found this on JL Audio's website.
"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."
So this seems to mean that the amp has 250w RMS power no matter how many ohms the sub is running(between 1.5 and 4ohms). So with a parallel wired dual 4 ohm sub (which would actually run at 2 ohms right?) the amp would run at 250w and the sun would run at 300w both at 2 ohms. This would underpower the sub by like 50w right?
Should I look into getting a 500w mono sub, the next level up?
"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."
So this seems to mean that the amp has 250w RMS power no matter how many ohms the sub is running(between 1.5 and 4ohms). So with a parallel wired dual 4 ohm sub (which would actually run at 2 ohms right?) the amp would run at 250w and the sun would run at 300w both at 2 ohms. This would underpower the sub by like 50w right?
Should I look into getting a 500w mono sub, the next level up?
Rated Power:
250 W RMS @ 1.5 ohm-4 ohm (11V-14.5V)
>>>
wow, that's weird, I sure thought "ohms" played a role in overall amplifier output.
Damping Factor:
>500 @ 4 ohm/50 Hz
>>>
That's a very nice DF on that amp, too bad it's only a 250 watts RMS
Who makes the sub?
You might want to get an amp with a little more "head room" to drive that sub a little harder, it'll sound better also with less distortion.
Maybe in the 400 RMS, 800 "peak" range for that sub.
Always buy a bigger amp than you will need, it'll be easier on the amp and help down the road when you want to add another sub or want to upgrade the sub for more bass later on.
I hope your running a "crossover" on that 10" or it's going to sound like hell.
Maybe cut it around 500-1000 HZ IMO
Last edited by B T; 03-23-2005 at 10:51 AM.
03-23-2005, 04:46 PM
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Crossover? I know very little about car stereo stuff just trying to get all the parts right the first time. I think I'll stick with that sub, but use a 500/1 amp from JL Audio. Sound good?
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03-23-2005, 11:53 PM
#8
Originally Posted by kraut187
OK so I think i understand, but probably not. I found this on JL Audio's website.
"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."
So this seems to mean that the amp has 250w RMS power no matter how many ohms the sub is running(between 1.5 and 4ohms). So with a parallel wired dual 4 ohm sub (which would actually run at 2 ohms right?) the amp would run at 250w and the sun would run at 300w both at 2 ohms. This would underpower the sub by like 50w right?
Should I look into getting a 500w mono sub, the next level up?
"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."
So this seems to mean that the amp has 250w RMS power no matter how many ohms the sub is running(between 1.5 and 4ohms). So with a parallel wired dual 4 ohm sub (which would actually run at 2 ohms right?) the amp would run at 250w and the sun would run at 300w both at 2 ohms. This would underpower the sub by like 50w right?
Should I look into getting a 500w mono sub, the next level up?
http://www.jlaudio.com/subwoofers/pdfs/10W3v2_MAN.pdf
You can ORDER or BUY them in 3 different configurations. You can get a sub with EITHER dual 2,4, or 6 ohm coils. They don't do all 3.
The JL Amps are a great piece. Because of their circuitry they are extremly adaptable. For not knowing much you made good choices on both subs and amp.
Alright. I'd get the 4 ohm subs if you haven's bought them yet. This would make it simple for wiring up. (paralleling together. Here's a good link to the different wiring configurations.)
http://www.sounddomain.com/shop/woof...dvc&x=119&y=10
http://www.sounddomain.com/shop/woof...dvc&x=118&y=11
http://www.sounddomain.com/shop/woof..._dvc&x=142&y=8
So. As you can see they developed the amp to work with their subs.
I'd step up to the bigger amp if you can afford it. Won't hurt.
here is a great link to help you understand more.
http://www.eatel.net/~amptech/elecdisc/srsparll.htm
03-24-2005, 12:04 AM
#9
Originally Posted by kraut187
Crossover? I know very little about car stereo stuff just trying to get all the parts right the first time. I think I'll stick with that sub, but use a 500/1 amp from JL Audio. Sound good?
Good idea. The amp has a built in crossover. This is a device for filtering frequencies. There a 4 types: High-pass, Low-pass, and Band-pass/Band-stop (high and low combined. You'll see a notch/band-stop type in car audioused in a EQ or tone control. That is how you go - in those settings)
http://www.sensorsmag.com/articles/0701/24/main.shtml
This is a little too indepth, but look over the begining part. You'll see what they are talking about.
Basically they keep a speaker woring in the Frequency range it is designed for.
A midrange or tweeter can't phyically repoduce a Subs freq well or at all. You'll damage the speaker by trying to make it do that.
Subs can produce properly from roughly 20hz-100hz (for the type you are used to seeing).
Mid-bass works from roughly 50/60hz-250/300hz.
Midrange from around 100/300hz-1.5kHz/5kHz.
Tweeters from around 1.5kHz-up.
For your Subs; you'll set the crossover to around 80-100hz.
03-24-2005, 12:07 AM
#10
Originally Posted by thunder550
Dual coil subs are more flexible that single....you can wire the two coils in series or parallel, making the sub either half or twice the impedance listed. Or, for really high powered stuff, people will run each coil off it's own amp. Make sure you match the effective ohm load of the sub with the amp. If you go too low, the amp can overheat and go into protect or fry, if you go higher than recommended you won't get as much power.
Effective loads:
Type / Series / Parallel
Dual 2 / 4 ohm / 1 ohm
Dual 4 / 8 ohm / 2 ohm
Dual 6 / 12 ohm / 3 ohm
What are the power ratings on the amp?
Some other things to consider....if you run two subs, you can series or parallel them also, doubling or halving the effective load above depending on how you do it. If you get a 2 channel amp and bridge the two channels for the subs, you're splitting the ohm load between the two channels.
For example, say you have a 2 ohm stable mono amp. You could configure it as follows:
-Two dual 2 ohm subs. Wire the coils in series to give you one 4 ohm load, then wire the two subs in parallel to give you a 2 ohm load on the amp.
-One dual 4 ohm sub. Wire the coils in parallel, making a 2 ohm load.
If you had a two channel 2 ohm stable amp and were bridging the channels, you could do it like this:
-Two dual 4 ohm subs. Wire the coils in series to give you 8 ohms per sub, then parallel the subs on the amp to get 4 ohms. Divide the 4 ohms by the two channels, and you get 2 ohms per channel.
-One dual 2 ohm sub. Wire the coils in series to get 4 ohms, then bridge the channels and divide by two to get 2 ohms per channel.
I hope this helps....let me know if you have more questions.
Effective loads:
Type / Series / Parallel
Dual 2 / 4 ohm / 1 ohm
Dual 4 / 8 ohm / 2 ohm
Dual 6 / 12 ohm / 3 ohm
What are the power ratings on the amp?
Some other things to consider....if you run two subs, you can series or parallel them also, doubling or halving the effective load above depending on how you do it. If you get a 2 channel amp and bridge the two channels for the subs, you're splitting the ohm load between the two channels.
For example, say you have a 2 ohm stable mono amp. You could configure it as follows:
-Two dual 2 ohm subs. Wire the coils in series to give you one 4 ohm load, then wire the two subs in parallel to give you a 2 ohm load on the amp.
-One dual 4 ohm sub. Wire the coils in parallel, making a 2 ohm load.
If you had a two channel 2 ohm stable amp and were bridging the channels, you could do it like this:
-Two dual 4 ohm subs. Wire the coils in series to give you 8 ohms per sub, then parallel the subs on the amp to get 4 ohms. Divide the 4 ohms by the two channels, and you get 2 ohms per channel.
-One dual 2 ohm sub. Wire the coils in series to get 4 ohms, then bridge the channels and divide by two to get 2 ohms per channel.
I hope this helps....let me know if you have more questions.
Good response man. Summed it up pretty well.
03-24-2005, 09:57 AM
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Thanks to everyone for the help. This is all damn good information and helped me understand this alot better then I did. I'll probably have more questions when all this stuff comes in, but thanks again for the help.
03-24-2005, 02:51 PM
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Heres a good site that explains ohms and how to wire up subs for different ohm configurations. It also has a calculator
http://www.bcae1.com/spkrmlti.htm
http://www.bcae1.com/spkrmlti.htm
03-24-2005, 11:55 PM
#14
Originally Posted by kraut187
So if i understand all this correctly this is how it would be wired to run the sub parallel wired at 2 ohms to the amp.
Yes. A quick way to do the math is like this: ohms (speaker)/#of loads
So 4ohm/2 (2 4 ohm coils) or would be like this for single voice coil 4ohm/2 (2 speaker @ 4ohms). This is the same difference.
Only works if the resistance is the same for all speakers.
03-24-2005, 11:56 PM
#15
Originally Posted by kraut187
Thanks to everyone for the help. This is all damn good information and helped me understand this alot better then I did. I'll probably have more questions when all this stuff comes in, but thanks again for the help.
Always ask. The only dumb questions are the ones you don't ask.
To make it easier when you do, Link this thread to your new one.
03-25-2005, 02:15 PM
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Originally Posted by kraut187
So if i understand all this correctly this is how it would be wired to run the sub parallel wired at 2 ohms to the amp.
Thats correct for a 1ohm load operation at the amp. JL says that amp is 1.5 ohm stable. You would PROBABLY be ok with a 1ohm load as long as the amp is kept cool and the gain is set at a concervative level
http://www.jlaudio.com/amps/5001.html
03-26-2005, 01:36 AM
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Originally Posted by 2MuchRiceMakesMeSick
Thats correct for a 1ohm load operation at the amp. JL says that amp is 1.5 ohm stable. You would PROBABLY be ok with a 1ohm load as long as the amp is kept cool and the gain is set at a concervative level
Req = 1/(1/R1+1/R2+1/R3+...+1/Rn). In this case, Req=1/(1/4+1/4) = 1/(2/4) = 4/2 = 2 ohms.
Originally Posted by kraut187
I thought it would be 2 ohms to the amp? Kinda confused now. Is there a better way to wire this exact setup?
03-26-2005, 03:52 PM
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Yes you are correct.
I was thinking that was a two channel amp.
If it would have been a two channel this would be a 1 ohm configuration at the amp once the channels were bridged
I was thinking that was a two channel amp.
If it would have been a two channel this would be a 1 ohm configuration at the amp once the channels were bridged
03-26-2005, 10:48 PM
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i had a 500/1 at 1ohm for about a year. As long as the gains are conservative, you will be ok running it at 1 ohm. Also with the jl 250/1, and all other jl amps, they are a bit underated, so running a 10w3 on a 250/1 would be just fine. And actually, by going with the 500/1 you would technically be "voiding the warranty". The 250/1 is actually the recommended amp for that sub
good luck
good luck