Hoping someone can help me out. A friend of mine recently gave me a JL Audio 12"w3 subwoofer in an enclosed box. It is a 6 ohm speaker. I know very little about what this means but I would like to put this speaker in my car. Please give me advise on what the best amp to buy to power this speaker. Thanks
Replies (11)
swez on 03/12/2004 06:59:04
12W3v2
Nominal Diameter: 12 inches (300 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): 0.46"-0.51" (11.7-13.0 mm) depending on specific model
Sealed Enclosure Range: 1.00-1.50 cu.ft. (28.3-42.0 liters)
Ported Enclosure Range: 2.00-3.00 cu.ft. (57.0-85.0 liters)
VRC™ Technology: YES
Elevated Frame Technology: YES
This model is difficult to work with as a single sub. The best choice amp would be a JL 500/1. A bit more power than that sub is rated for, but gain adjustments would be an option to reduce power to sub. Expensive amp though.
Also, The JBL BP300.1 or 600.1 would work. The 300.1 would deliver ~200 watts RMS, while the 600.1 would net ~400 watts RMS. These are wallet friendly amps and work very well at 1-4 ohm loads.
The best you can do, is to wire both voice coils in parallel for a net 3 ohm load. Just go easy on the amp gain settings to prevent damage to sub.
Swez
dafunkdoc on 03/12/2004 14:13:04
Thanks for your help. Can you briefly explain to me what is difficult about a 6ohm speaker and is it dangerous to hook up to the wrong amplifier?
eldevioso on 03/12/2004 17:27:49
That really is a broad topic, and swez is as gifted as any to explain, but here's my quick thought:
My understanding of ohms is that they're a measure of resistance. Therefore it directly affects how hard the amp has to work. If you have an amp that is rated at 4 ohms and you hook up a speaker that has less than 4 ohms, without adjusting the gains you risk hurting your amplifier because it can't operate in that manner for a prolonged time. On the other hand if you hook up a sub with higher than 4 ohms resistance the amp doesn't have to work as hard and therefore will run cooler and last a lot longer, however, at this point you are running your amp below its optimal settings.
The interesting thing with your sub is according to Swez's specification post, it is dual voice coil. This means that in fact there are Two 6ohm components (called voice coils) in your single speaker. The tricky part is that you can wire these two voice coils in 2 ways. One, wiring them in series will result in 12 ohm load since it adds the resistance of each of the two voice coils together. But as I mentioned before this 12 ohm resistance will be much higher than the resistance of any amp you're likely to come accross so you'll get SERIOUSLY reduced performance. The other option is to wire them in parallel as Swez mentioned resulting in a 3 ohm load. This more closely matches most amps that will run in ranges between 1-4 ohms as Swez mentioned.
The tricky part is, that you will most likely get an amp that either runs at 4 ohms, or will overpower the sub while running at less ohms than 4. In both cases you will have to adjust the gain on the amp to ensure that you don't overpower your sub, or over-tax your amplifier.
Setting the gain can be explained later when you actually have an amp. For now though, the gain setting can be weakly compared to a faucet where adjusting the faucet knob (the gain on the amplifier), results in the water (the amount of power), flowing more freely or less freely depending on how you set it.
So in summary, because your speaker has two 6ohm voice coils, you'll have to wire it to have a 3ohm load. Many amps, especially ones that are hand me downs or are found by the novice installer (including myself) are 4ohm stable. Therefore running a 3ohm speaker (yours) will most likely result in the failure of the amp or the sub in the long run, unless you adjust the gain. Therefore it is important to understadn the power and ohm stability of your amplifier, adn then to adjust your gain settings accordingly to ensure you don't ruin your equipment.
Sorry it wasn't so brief, but as I said you asked a VERY broad question, I only skimmed the surface.
p.s. I know this was more simple in terms and language but I think the general point was made.
swez on 03/12/2004 18:07:20
Perfect... a guy more long on wind than me... GRIN
Just a few additions... use a MONO amp here as a 2 channel amp will not operate well in 3 ohm loads when bridged. Most Class D MONO amps are stable with 2 ohm loads. A few can even manage 1 ohm loads. The JBL Power series is one of the few that can do a 1 ohm load.
I assume you have the 12W3v2, dual Voice coil sub. If this is incorrect, please advise. It is not dangerous to use a 6 ohm speaker on most amps I know about. Just less power that is optimal for the amp you use. High resistance means less power flow to the sub from typical car amps.
Swez
PS Glad you are back to help out Eld.
dafunkdoc on 03/12/2004 21:06:23
First off, I'd like to thank you for your speedy responses to my novice questions. Secondly, I appreciate that I have gotten more information from you, than any salesperson I have talked to. The speaker product is 12w3d6. The power handling of this sub is 250W (RMS), however the person who gave it to me said that he had 400 watts to it with no problems. I checked prices for the amps recommended and I can get either the jbl bp300.1 or the jbl bp600.1......both are well affordable. Of the two which one would produce better sound, and are either amp dangerous to use? Thanks again for all the help
swez on 03/12/2004 22:47:02
Thanks for clarifying the sub you have. The JBL 300.1 will net close to 250 watts RMS to this sub, when wired in parallel... 3 ohms load. The 600.1 will net close to 450 RMS @ 3 ohms. The 600.1 is a bit strong for this sub. The 300.1 is a good match up, especially if you go ported enclosure for maximum output.
Here's a link to sub specs and enclosure recomendations for this sub. Yes. you could buy a JL 250/1 mono amp... but price may be a tad high.
If you go ported and use the JBL 300.1, I recommend subsonic filtering to protect your sub. We can discuss that if you choose that route.
http://www.jlaudio.com/subwoofers/pdfs/12W3_MAN.pdf
Swez
PS I am a salesman too... but place more emphasis on customer satifaction than how much cash I can extract from your wallet before you leave the store. Smaller shops with older, more experienced people will serve you better than chain stores with high turn over rates.
dafunkdoc on 03/13/2004 21:34:11
Sweet.....good advice.......i found a jbl 300.1 amp on ebay for low......the buyer said that he used a 1 farad capacitor. What exactly is this and do I need one?
swez on 03/13/2004 23:57:25
It's a better paper weight than anything else. The Cap I mean... auto jewlery, but not much more. As long as you have an ATL that can put out a steady 80A. of current, you'll be fine w/o the Cap.
If you note headlight dimming upon install, get a larger CCA rated battery. An 800 CCA rated battery has 2,000,000 time more storage capacity than a 1 Farad cap. It acts like a small buffer of say 0.5Kb of ram on your computer. The larger battery is more like 1Gb of ram. Both cost about the same, but one is superior to the other.
Swez
cplkittle on 03/14/2004 23:49:47
for the 300.1 I doubt you will need a cap at all. I ran a 600w kenwood on my factory battery for almost a year. The only reason I bought a bigger battery is because I added an additional 500w amplifier for my mids/highs. Only then did I notice my lights dimming. If you go with the 600.1 the gain will be turned down so much that I doubt it will even pull enough to dim the lights.
Like Swez said, ' IF ' you notice headlight dimming....
don't fix what isn't broken.. however in this case an upgrade is not going to damage anything except your savings account.
dafunkdoc on 03/15/2004 14:26:30
Thanks again for all your help
swez on 03/15/2004 15:13:47
You bet!
Swez
Replies (11)
swez on 03/12/2004 06:59:04
12W3v2
Nominal Diameter: 12 inches (300 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): 0.46"-0.51" (11.7-13.0 mm) depending on specific model
Sealed Enclosure Range: 1.00-1.50 cu.ft. (28.3-42.0 liters)
Ported Enclosure Range: 2.00-3.00 cu.ft. (57.0-85.0 liters)
VRC™ Technology: YES
Elevated Frame Technology: YES
This model is difficult to work with as a single sub. The best choice amp would be a JL 500/1. A bit more power than that sub is rated for, but gain adjustments would be an option to reduce power to sub. Expensive amp though.
Also, The JBL BP300.1 or 600.1 would work. The 300.1 would deliver ~200 watts RMS, while the 600.1 would net ~400 watts RMS. These are wallet friendly amps and work very well at 1-4 ohm loads.
The best you can do, is to wire both voice coils in parallel for a net 3 ohm load. Just go easy on the amp gain settings to prevent damage to sub.
Swez
dafunkdoc on 03/12/2004 14:13:04
Thanks for your help. Can you briefly explain to me what is difficult about a 6ohm speaker and is it dangerous to hook up to the wrong amplifier?
eldevioso on 03/12/2004 17:27:49
That really is a broad topic, and swez is as gifted as any to explain, but here's my quick thought:
My understanding of ohms is that they're a measure of resistance. Therefore it directly affects how hard the amp has to work. If you have an amp that is rated at 4 ohms and you hook up a speaker that has less than 4 ohms, without adjusting the gains you risk hurting your amplifier because it can't operate in that manner for a prolonged time. On the other hand if you hook up a sub with higher than 4 ohms resistance the amp doesn't have to work as hard and therefore will run cooler and last a lot longer, however, at this point you are running your amp below its optimal settings.
The interesting thing with your sub is according to Swez's specification post, it is dual voice coil. This means that in fact there are Two 6ohm components (called voice coils) in your single speaker. The tricky part is that you can wire these two voice coils in 2 ways. One, wiring them in series will result in 12 ohm load since it adds the resistance of each of the two voice coils together. But as I mentioned before this 12 ohm resistance will be much higher than the resistance of any amp you're likely to come accross so you'll get SERIOUSLY reduced performance. The other option is to wire them in parallel as Swez mentioned resulting in a 3 ohm load. This more closely matches most amps that will run in ranges between 1-4 ohms as Swez mentioned.
The tricky part is, that you will most likely get an amp that either runs at 4 ohms, or will overpower the sub while running at less ohms than 4. In both cases you will have to adjust the gain on the amp to ensure that you don't overpower your sub, or over-tax your amplifier.
Setting the gain can be explained later when you actually have an amp. For now though, the gain setting can be weakly compared to a faucet where adjusting the faucet knob (the gain on the amplifier), results in the water (the amount of power), flowing more freely or less freely depending on how you set it.
So in summary, because your speaker has two 6ohm voice coils, you'll have to wire it to have a 3ohm load. Many amps, especially ones that are hand me downs or are found by the novice installer (including myself) are 4ohm stable. Therefore running a 3ohm speaker (yours) will most likely result in the failure of the amp or the sub in the long run, unless you adjust the gain. Therefore it is important to understadn the power and ohm stability of your amplifier, adn then to adjust your gain settings accordingly to ensure you don't ruin your equipment.
Sorry it wasn't so brief, but as I said you asked a VERY broad question, I only skimmed the surface.
p.s. I know this was more simple in terms and language but I think the general point was made.
swez on 03/12/2004 18:07:20
Perfect... a guy more long on wind than me... GRIN
Just a few additions... use a MONO amp here as a 2 channel amp will not operate well in 3 ohm loads when bridged. Most Class D MONO amps are stable with 2 ohm loads. A few can even manage 1 ohm loads. The JBL Power series is one of the few that can do a 1 ohm load.
I assume you have the 12W3v2, dual Voice coil sub. If this is incorrect, please advise. It is not dangerous to use a 6 ohm speaker on most amps I know about. Just less power that is optimal for the amp you use. High resistance means less power flow to the sub from typical car amps.
Swez
PS Glad you are back to help out Eld.
dafunkdoc on 03/12/2004 21:06:23
First off, I'd like to thank you for your speedy responses to my novice questions. Secondly, I appreciate that I have gotten more information from you, than any salesperson I have talked to. The speaker product is 12w3d6. The power handling of this sub is 250W (RMS), however the person who gave it to me said that he had 400 watts to it with no problems. I checked prices for the amps recommended and I can get either the jbl bp300.1 or the jbl bp600.1......both are well affordable. Of the two which one would produce better sound, and are either amp dangerous to use? Thanks again for all the help
swez on 03/12/2004 22:47:02
Thanks for clarifying the sub you have. The JBL 300.1 will net close to 250 watts RMS to this sub, when wired in parallel... 3 ohms load. The 600.1 will net close to 450 RMS @ 3 ohms. The 600.1 is a bit strong for this sub. The 300.1 is a good match up, especially if you go ported enclosure for maximum output.
Here's a link to sub specs and enclosure recomendations for this sub. Yes. you could buy a JL 250/1 mono amp... but price may be a tad high.
If you go ported and use the JBL 300.1, I recommend subsonic filtering to protect your sub. We can discuss that if you choose that route.
http://www.jlaudio.com/subwoofers/pdfs/12W3_MAN.pdf
Swez
PS I am a salesman too... but place more emphasis on customer satifaction than how much cash I can extract from your wallet before you leave the store. Smaller shops with older, more experienced people will serve you better than chain stores with high turn over rates.
dafunkdoc on 03/13/2004 21:34:11
Sweet.....good advice.......i found a jbl 300.1 amp on ebay for low......the buyer said that he used a 1 farad capacitor. What exactly is this and do I need one?
swez on 03/13/2004 23:57:25
It's a better paper weight than anything else. The Cap I mean... auto jewlery, but not much more. As long as you have an ATL that can put out a steady 80A. of current, you'll be fine w/o the Cap.
If you note headlight dimming upon install, get a larger CCA rated battery. An 800 CCA rated battery has 2,000,000 time more storage capacity than a 1 Farad cap. It acts like a small buffer of say 0.5Kb of ram on your computer. The larger battery is more like 1Gb of ram. Both cost about the same, but one is superior to the other.
Swez
cplkittle on 03/14/2004 23:49:47
for the 300.1 I doubt you will need a cap at all. I ran a 600w kenwood on my factory battery for almost a year. The only reason I bought a bigger battery is because I added an additional 500w amplifier for my mids/highs. Only then did I notice my lights dimming. If you go with the 600.1 the gain will be turned down so much that I doubt it will even pull enough to dim the lights.
Like Swez said, ' IF ' you notice headlight dimming....
don't fix what isn't broken.. however in this case an upgrade is not going to damage anything except your savings account.
dafunkdoc on 03/15/2004 14:26:30
Thanks again for all your help
swez on 03/15/2004 15:13:47
You bet!
Swez
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