How ?? Change the impedance of a speaker (sub)

[Cattlegod]

Does anyone know how to do this? or if it is even possible?

Story: i have 2 subs, they are DVC and each coil is 4 ohms. I need to change the resistance of the coils to 8 ohms. my current setup is i have two of these speakers in series to create a 4 ohm load circuit for an amp. well i just repaired a kick ass amp that blew out a few years back and would like to run each speaker off of each amp. 2 ohms of resistance is too low ( i guess it is ok if i just don't turn it up all the way ), so i need to double the resistance for each coil so i get 4 ohms out of the speaker. is there any way i can just take the speaker apart and swap out a component? or is this stuff factory glued or something so i can't tamper with it?

 

[minendo]

I may have this backwards, but doesnt running them in parallel cause them to run at 4 ohms?

 

[Cattlegod]

the more i think about it i see the only way might be to replace the coil

in parallel it drops to 2 ohms, series up to 8 ohms. i need it to be 4. hmm...

 

[Mucman]

Couldn't you just drive the sub with 1 VC?

 

[Cattlegod]

Couldn't you just drive the sub with 1 VC?

ohhh, that is a good question. is this possible?

 

[Mucman]

I believe that is one of the benifits of DVCs, you can configure them in numerous ways...

 

[SViscusi]

Follow this wiring guide

 

[zephyrprime]

Wait, I'm not sure I understand this. You have two amps and two subs that are 4ohms each? Couldn't you just connect one sub to one amp and the other sub to the other amp?

 

[Ns1]

Couldn't you just connect one sub to one amp and the other sub to the other amp?

 

[Cattlegod]

Wait, I'm not sure I understand this. You have two amps and two subs that are 4ohms each? Couldn't you just connect one sub to one amp and the other sub to the other amp?

i have 2 amps, each amp puts out about 500W RMS at 4 ohms bridged.
I have 2 subs, they are DVC and each coil is 4 Ohms. ( giving 2 or 8 ohms per sub ).

Each sub can handle 500W RMS. however, as suggested above, if i run it off one coil i think i limit myself to only 250W RMS, right?

would i be fine running it at 2 Ohms and turning all the gains down and hoping i don't fry the amps?

 

[Lithium381]

Hrm, you can't just change the resistance of the coils, however, you can wire them a few ways to get the desired effect. if you want a total of 4ohms, and each coil is 4 ohms.....what you should do is run the subs in series, but with the coils per sub in parallel(that would give overall of 4ohms) what you can do is use a 4ohm resistor, and use that to "trick" the amp into thinking there is another speaker/coil there...PM me and i can help you with a wiring schematic......good luck!

if you do decide to PM me, include information on how you are going to be running this, like are the subs stereo, or are you bridging the amp etc!

 

[Lithium381]

Originally posted by: Cattlegod

Wait, I'm not sure I understand this. You have two amps and two subs that are 4ohms each? Couldn't you just connect one sub to one amp and the other sub to the other amp?

i have 2 amps, each amp puts out about 500W RMS at 4 ohms bridged.
I have 2 subs, they are DVC and each coil is 4 Ohms. ( giving 2 or 8 ohms per sub ).

Each sub can handle 500W RMS. however, as suggested above, if i run it off one coil i think i limit myself to only 250W RMS, right?

would i be fine running it at 2 Ohms and turning all the gains down and hoping i don't fry the amps?

Okay, why can't you just have the amps drive a coil per channel? Woulnd't that have 4ohms?? That's an amp per sub, you get 4 ohms, and should be enough power easy.....

 

[Cattlegod]

Originally posted by: Lithium381
Hrm, you can't just change the resistance of the coils, however, you can wire them a few ways to get the desired effect. if you want a total of 4ohms, and each coil is 4 ohms.....what you should do is run the subs in series, but with the coils per sub in parallel(that would give overall of 4ohms) what you can do is use a 4ohm resistor, and use that to "trick" the amp into thinking there is another speaker/coil there...PM me and i can help you with a wiring schematic......good luck!

if you do decide to PM me, include information on how you are going to be running this, like are the subs stereo, or are you bridging the amp etc!

this doesn't allow the use of the 2nd amp. at the moment i have 500W effective power, i want to increase it to 1000 W effective power by using the 2nd amp i fixed. it looks like the only option i have is to wire the DVC's in parallel to give me 2 ohms, and then run each amp at 2 ohms and turn all the settings to min.




EDIT: if the speaker can handle 500W RMS total, then each coil has 250W, which will be blown out by the 500W i would be running to it, or do you think it can handle it?

 

[Lithium381]

Originally posted by: Cattlegod

Originally posted by: Lithium381
Hrm, you can't just change the resistance of the coils, however, you can wire them a few ways to get the desired effect. if you want a total of 4ohms, and each coil is 4 ohms.....what you should do is run the subs in series, but with the coils per sub in parallel(that would give overall of 4ohms) what you can do is use a 4ohm resistor, and use that to "trick" the amp into thinking there is another speaker/coil there...PM me and i can help you with a wiring schematic......good luck!

if you do decide to PM me, include information on how you are going to be running this, like are the subs stereo, or are you bridging the amp etc!

this doesn't allow the use of the 2nd amp. at the moment i have 500W effective power, i want to increase it to 1000 W effective power by using the 2nd amp i fixed. it looks like the only option i have is to wire the DVC's in parallel to give me 2 ohms, and then run each amp at 2 ohms and turn all the settings to min.




EDIT: if the speaker can handle 500W RMS total, then each coil has 250W, which will be blown out by the 500W i would be running to it, or do you think it can handle it?

yeah, it can handle it, as long as you don't play it too loud, it doens't always put out 500w, just when you're blasting it.....(sorry about before, i hadn't seen the post that was put up moments before mine! what about the idea i posted just moments ago?

 

[Cattlegod]

hmm, i think i will try that ( using only 1 coil ). the warranty on the subs is still good for another year or two. i got the amps used, so i don't want to ruin those

thanks for your input ATOT

 

[Shockwave]

You wont fry the amp unless you run it to a load less then what its rated, and even then SOME amps will do it. So, first. What brand of amp is it? What are the specs? Keep in mind on most amps halving impedence double power. ie..2 ohm is double the watts of 4 ohm.
Secondly, gains are directly porportional to your head unit. It matches the HU's output to the amp..ie..some HU's are 1V, some 2V, well, the amp needs to know the power of the signal, hence a gain. A 5V HU would have a lower gain setting then a 1V (Thats rEALLY basic...Theres alot mroe to it) Also, as for power handling on the speaker, depends on the speaker. If thats a good speaker, it'll handle well over the rated 500 watts all day long.
So, list what brands the stuff is. As for getting 4 ohm load, if that what you want you can either run 1 amp per VC, which gives you 2 amps on 2 coils or 2 amps pre speaker. Or, you can run 2 speakers, run the coils in parrellel and the amps to the speakers in series (or something like that) But ya, having 2 amps and 2 DVC subs gives you wiring options out the freakin wazoo! And as long as the gains are set right and you dont drive the amps into a load lower then their rating, you wont have the meltdown on ya unless there just bad (defective0 amps.

 

[Jerboy]

Originally posted by: Cattlegod

Couldn't you just drive the sub with 1 VC?

ohhh, that is a good question. is this possible?

Parallel=2ohms

Series=8ohms

When you series or parallel two voice coils, they better damn be in phase. If you connect them out of phase, coils will fight each other and tries to pull the cone in opposite direction.

 

[Cattlegod]

Originally posted by: Shockwave
You wont fry the amp unless you run it to a load less then what its rated, and even then SOME amps will do it. So, first. What brand of amp is it? What are the specs? Keep in mind on most amps halving impedence double power. ie..2 ohm is double the watts of 4 ohm.
Secondly, gains are directly porportional to your head unit. It matches the HU's output to the amp..ie..some HU's are 1V, some 2V, well, the amp needs to know the power of the signal, hence a gain. A 5V HU would have a lower gain setting then a 1V (Thats rEALLY basic...Theres alot mroe to it) Also, as for power handling on the speaker, depends on the speaker. If thats a good speaker, it'll handle well over the rated 500 watts all day long.
So, list what brands the stuff is. As for getting 4 ohm load, if that what you want you can either run 1 amp per VC, which gives you 2 amps on 2 coils or 2 amps pre speaker. Or, you can run 2 speakers, run the coils in parrellel and the amps to the speakers in series (or something like that) But ya, having 2 amps and 2 DVC subs gives you wiring options out the freakin wazoo! And as long as the gains are set right and you dont drive the amps into a load lower then their rating, you wont have the meltdown on ya unless there just bad (defective0 amps.

thanks for the reply, here is what i have:

Amp 1: MTX 2300 - 2 channel amp rated at 600x1 rms at 4 ohm max.
Amp 2: HiFonics Atlantis X - 2 channel amp rated at 500x1 rms at 4 ohm max.

Sub 1: Rockford Fosgate HX2 DVC - 4 ohm coils rated at 500 w rms
Sub 2: same.

i'm going to run 1 coil off each sub for the first try. if i notice distortion from the coil being over exterted ( which is a high probability ) then i will use both coils making a 2 ohm load and use that on the amps.