posted
K....I have two DVC subs...each coil at 1.8. Would it be ok to wire the two subs in series???..like have each sub wired in parallel, to give me .9 a piece...then the subs in series to give me 2 ohms at the amp??? What would be the bad side of this...any ideas?
posted
it'd have to be more of a series/parallel wiring for what you're talking about. instead of wiring each sub in parallel like you're saying and then wiring the two in series, you would have to wire each sub in series and then parallel the two together.
each sub in series would have an impedence of 3.6, then when you parallel the two together it would cut it back down to 1.8. JL Audio's website shows exactly how to do this. just look at the example labled 2DVC Drivers with voice coils in series/parallel (third one down) and it will show you exactly how to wire it. on the site it shows that this gives 2 DVC drivers with 2 ohm vioce coils a final impedence of 2 ohms, which is pretty much what you have.... good luck
-------------------- Current Setup: HU: Pioneer DEH-P8400MP CD Changer: Pioneer CDXP1280 12 Disc Changer XM Radio Front Stage: Infinity Kappa 693.5i Rear Stage: Hifonics Zeus HZCX6.2neo Components Subs: 2 Adire Audio Tempest's Enclosure: Custom Made sealed MDF w/rear Plexiglass windows and interior blue neon lighting Mono Amp: JBL 1200.1 Multi Channel Amp: JBL PX300.4 (75Wx4 @ 4 ohm) All KnuKonceptz.com wiring About 100 sq. ft. of FatMat Posts: 95 | From: louisville | Registered: Dec 2003
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posted
OK JL says that series connections between subs should be avioded at all cost but they never say why...nothing in the DVC FAQ seems to give any indication as to why this is. Any ideas?
Anyone care to take a guess? Awhile back there was a conversation about this and someone brought up that in one wiring configuration the Bl of each sub magically gets cut in half! I personally can't think of a single reason why one wiring would be preferable over the other.
Ash
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posted
i've not heard anything about bl curves but i guess something must not be right about wiring two subs series together because honestly i've never really heard of it.... who knows though, there's a lot i've not heard of
-------------------- Current Setup: HU: Pioneer DEH-P8400MP CD Changer: Pioneer CDXP1280 12 Disc Changer XM Radio Front Stage: Infinity Kappa 693.5i Rear Stage: Hifonics Zeus HZCX6.2neo Components Subs: 2 Adire Audio Tempest's Enclosure: Custom Made sealed MDF w/rear Plexiglass windows and interior blue neon lighting Mono Amp: JBL 1200.1 Multi Channel Amp: JBL PX300.4 (75Wx4 @ 4 ohm) All KnuKonceptz.com wiring About 100 sq. ft. of FatMat Posts: 95 | From: louisville | Registered: Dec 2003
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posted
hey i'm from louisville to Alex, just here to say hey.
I hope that isnt true cuz when i am done ordering, i will have 2 ZRS-10s bridged together with 2 Audiobahn Immortal 15s series\parallel wired at 2 ohms to shove em.
posted
BL is not affected. B = the magnetic flux strength of the motor and L = the length of wire inside of the gap. So BL in tesla meters is merely the product of those to variables.
ok ok ok
People say there is an SQ advantage to seriesing coils as opposed to parallel. What is this from and is there any truth to the matter?
Shadowstar care to elaborate? Make everyone's brain hurt again....
-------------------- 2005 Florida Street C Champion 2004 SBN Street C Champion 2004 SBN IDBL No Wall Champion 2003 NOPI Nats Street B Champion
posted
Bumpin Yota your analysis of the Bl issue is exactly the case I made in the post awhile back. However, some people kept making the opposite point.
Here's how I see it.
1) parallel coils on each sub, then put the two subs in series.
In this case, the total amount of current that goes through each sub is exactly the same. Now, once the current enters each sub, 50% of the total current should go through each coil, if its a DVC. Of coarse, this isn't strictly true, because in reality each woild will have very slight difference in impedence...so perhaps 49.5% of the current goes to one coil while 50.5% goes to the other. These are just amde up numbers.
2)Coils on each sub in series, then put the subs in parallel.
In this case, the same voltage is going to be applied to eachsub. However, because of the slight difference in the coils between the subs, each sub will get a slightly different amount of current.
Basically, in one case (#2) each of the two coils on each sub sees the same amount of current, but slightly different amount of voltage. In the other case (#1) the coils on each of the subs see the same voltage, but get a slightly different current.
Now, I don't have any numbers on what the average deviation is on subwoofer voice coils. I would bet that its very small. But, this is the ONLY difference I can see between the two wiring schemes. Regardless of which way you wire things up, the back-emf field produced is going to be just about the same.
Shadowstar, any input?
Ash
-------------------- ****************************** ****************************** Posts: 1130 | From: Los Angeles, CA | Registered: Aug 2001
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quote:Originally posted by Ash: Bumpin Yota your analysis of the Bl issue is exactly the case I made in the post awhile back. However, some people kept making the opposite point.
Here's how I see it.
1) parallel coils on each sub, then put the two subs in series.
In this case, the total amount of current that goes through each sub is exactly the same. Now, once the current enters each sub, 50% of the total current should go through each coil, if its a DVC. Of coarse, this isn't strictly true, because in reality each woild will have very slight difference in impedence...so perhaps 49.5% of the current goes to one coil while 50.5% goes to the other. These are just amde up numbers.
2)Coils on each sub in series, then put the subs in parallel.
In this case, the same voltage is going to be applied to eachsub. However, because of the slight difference in the coils between the subs, each sub will get a slightly different amount of current.
Basically, in one case (#2) each of the two coils on each sub sees the same amount of current, but slightly different amount of voltage. In the other case (#1) the coils on each of the subs see the same voltage, but get a slightly different current.
Now, I don't have any numbers on what the average deviation is on subwoofer voice coils. I would bet that its very small. But, this is the ONLY difference I can see between the two wiring schemes. Regardless of which way you wire things up, the back-emf field produced is going to be just about the same.
Shadowstar, any input?
Ash
Hmmm interesting scenario. If you have the choice of having diffential voltage or current in a single DVC sub, it'd be voltage. The reason being less stress to the coils and former of the sub as it is the current in a coil that determines magnetic strength of that coil. BUT as you said the differences would be very very small....
ooooo Shadowstar... I gots beer...
-------------------- 2005 Florida Street C Champion 2004 SBN Street C Champion 2004 SBN IDBL No Wall Champion 2003 NOPI Nats Street B Champion
posted
think about this for 2 seconds: -we take a 4ohm dvc sub wire each coil in series, giving us 8 ohm. now we want to pass 1 watt through it, 8 = V*V V= 2.83V and I= 0.35A
now we put the coils in parallel giving us 2 ohm impedance to the amplifier. 2 = V*V V= 1.42V and I= 0.707A
Our first assumption would be that 2 ohms is better than 8 since for 1 watt, you get twice the current. this is incorrect, the truth is, they are both identical.
for the first case, .35 amps passes thru each turn of the vc(the whole way thru) in a constant magnetic field. for the parallel configuration, half of the total current passes thru each coil, so .35 amps for every single turn in the gap. since we used the same sub for this experiment, B is the same, N(turns) is the same and Re per coil is the same. If we were to take a stab at guessing what the Bl would be for each configuration, we would guess it is the same in both cases. And then we would discover the true meaning of V vs I, that there is none. The only thing that matters is P, power fed to the driver.
Posts: 768 | From: Ottawa, On, Canada | Registered: May 2000
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posted
Reread my post and Bumpin' Yota's response. We're not talking about an ideal situation in which both VC's in a DVC sub are exactly the same. We're talking about what kinds of effects the small differences in the DVC's coils can have. We're talking about differences in impedence, and, hence, differences in the amount of power delivered to each coil.
So, while your assertion that: power fed into the coil is what matters is correct, it doesn't really pertain to the discussion at hand.
Ash
[ 12-16-2003, 08:08 AM: Message edited by: Ash ]
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