[DaTsUn 12o0 uTe]

I have a 12" sub ... DVC 4ohm ... Can i use only 1 of the voice coils? or do i have to use both at either 2ohm or 8ohm ...

IF i have to use both can run 2 amps 1 to each VC?

Ta :)

[Nav2k]

yes u can use one voice coil, not sure why u'd want to tho....if u have one channel, its prolly from a monoblock which u can run at 2ohms and it'd be stable most likely.

[forbidden]

Do not run two amps to one sub, it is not a great idea. Most amps are not matched for tolerance levels and unless you have a o-scope to accurately set the output levels I will not recommend doing this. No problem using one of the voice coils or wiring the sub in series to 8 ohms or parallel to 2 ohms depending on the amp that you want to use.

[BlackRain]

Nav2k said:

yes u can use one voice coil, not sure why u'd want to tho....if u have one channel, its prolly from a monoblock which u can run at 2ohms and it'd be stable most likely.

Sure about this??...

I can't remember exactly where I read it..but for some reason...I thought using only 1 voice coil on a DVC sub was a HUGE no-no.. :shock:

[RTTZ]

Nav2k said:

yes u can use one voice coil

No sub manufacturer will recommend this and a matter of fact will warn you not to do this! unless of course you make all your calculations based on one voice coil for the box, etc. etc. Which means that you will have to find the T/S parameters etc. by yourself as the ones by supplied by the sub manufacturer will be for both voice coils hooked up.

Bye,
Mo

[RTTZ]

DaTsUn 12o0 uTe said:

IF i have to use both can run 2 amps 1 to each VC?

Yes, if the amps are strapable. ie. one amp controls gain control for both amps.

Bye,
Mo

[bob]

forbidden said:

Do not run two amps to one sub, it is not a great idea. Most amps are not matched for tolerance levels and unless you have a o-scope to accurately set the output levels I will not recommend doing this. No problem using one of the voice coils or wiring the sub in series to 8 ohms or parallel to 2 ohms depending on the amp that you want to use.

Why would you need to do that? Just play a tone, and use a multimeter to match the gains.

[Bassaholic]

Guys, when running two amps on one sub, you do not need to tightly match the gains. It won't really matter, as long as they are reasonably close. Plenty of people on CAA have done this over the years just by setting the gain by eye and have had no problems.

Secondly, it is not really recommended to run only one coil, as the power handling will be decreased. Secondly, you have to short out the coil that is not connected to an amp. So you just run a very short bit of wire from the +'ve to the -'ve of the coil that is not hooked up to anything. Otherwise the T/S parameters will change.

[BlackRain]

If it comes down to it..u'd probably be better off running both coils with less power, than to try and run a single VC in an attempt to maximise the power ur getting to the amp.

[tuneman]

shorting the unused coil is very bad idear!! :shock:
due to its movement it generates its own induced currents' shorting it out will do just as you said 'short it out' its like having the handbrake on whilst driving!!, does the same thing as having a metalic former that dosen't have a gap' to prevent eddie currents, when you put the wire in it completes the circiut :( and kills the subs efficiency.
who gave you that info?
there's no reason you carn't use just one coil, it just means your sub has to lug around the extra weight of a spare coil, it may change its t/s specs but not really enough to get hugely worried about. its just not being used to its full potential :)

[RTTZ]

Bassaholic said:

Secondly, it is not really recommended to run only one coil, as the power handling will be decreased. Secondly, you have to short out the coil that is not connected to an amp. So you just run a very short bit of wire from the +'ve to the -'ve of the coil that is not hooked up to anything. Otherwise the T/S parameters will change.

Hey Bassaholic,
If you short one of the coils and only hook up one coil to an amp, then the sub sees a different charge on the coil than what it was designed to get.

Won't this change the T/S parameters in itself? Cos the coil -magnet relationship will change? (from manfacturer's T/S parameters that were measured with both coils seeing a charge either in a parallel or series config).

Bye,
Mo

[tuneman]

you may also find that the combined weight of the two coils is equal to the equivilant single coil version, seeing as they generally will only have half the amount of wire each.
so they don't change much, if at all

[Beany]

WOW there are some really huge differences in ideas here!

should we all agree on something before this dude fries his sub or worse an amp or something catches fire!!!!

[findog]

I remember reading some pretty detailed .pdf's on the shiva subs (dvc) and they mentioned driving one voice coil, and connecting a variable resistor to the contacts of the second coil. depending on the resistance you can change the damping of the sub and tune the q of the sub.

if anyone is interested i'll try to dig it up.

[tuneman]

funny you should mention that cos its a sweet idear, the velodyne sub has something that works on the same principal, with a computer controling the spare coil it can regulate the cones movement. :)