Ford Forums banner

Single voice coil or dual voice coil subs? Whats the difference?

10K views 19 replies 9 participants last post by  MEX351 
#1 ·
Ok all you stereo buffs out there. Could somebody explain to me the difference between a dual voice coil and a single voice coil sub? What does it do and do they sound any different when played?

Please elaborate....
 
#5 ·
a Speaker has a Voice coil,

this produces the sound for your speaker,

Each voice coil has a Impedance rating,
in the case of a single voice coil, most have a Rating of 4 Ohm Impedance and or resistance.

If you take a look at the ratings on your amps, then you will notice they are rated at X Amount of power at 4 Ohm, X amount of power at 2 ohm, and if it's a D class, or really high end amp it will have a Rating at 1 Ohm, or even lower.

Most amplifiers can handle 4 Ohm Loads as standard, for this reason almost all car speakers at standard 4 Ohm,

Eg: a Amp that puts out 50 Watts at 4 Ohm loading, in most cases puts out 100 Watts at 2 Ohms, because it is half the load, but this is not always the case, and often depends on the Amplifier design.

This being said, Not all amps can cope with a 2 Ohm load and even less often a 1 Ohm Load. Often Amplifiers will be able to cope with a 2Ohm Load in stereo, but not in bridged mono.

EG: A 2 x 50 Watt amp, can also put out 2 x 100 at 2 Ohm, but when you bridge it to a Single Channel, MONO it puts out 200 Watts x 1 but at 4 Ohm. Putting a 2 Ohm load on this amp, will not neccessarily make 400 Watts, and often will damage or destroy the amp if you do so while it is bridged.

what does all this have to do with Subs and how many voice coils it has?

Simple, if you have 1 Voice coil, and it's rated at 4 Ohm, you plug it into a amp, it has a 4 ohm load, and thats that.

However a Dual Voice coil sub has 2 voice coils, Often they are Rated at Dual 4 Ohm Voice coils.

Now you must connect BOTH voice coils to your amp, to avoid damaging the subwoofer, and they must be wired correctly or it won't work.

Now lets say you have a Dual 4 Ohm voice Coil Sub, you have 2 Specific ways you can Wire it.

You can wire it in Series or Parralel..

Series will actually produce a 8 Ohm Load for your amp, EG: if your amp is rated at 100 watts at 4 Ohm, putting a 8 Ohm loading on your amp will cause it's output to drop to around 50 watts (again depending on the amp design).

While this all might seem bad, a 8 Ohm loading can often produce more dynamic bass, and better quality sound as long as power is not dropped too much, For this reason 8 and 16 Ohm is often/normally used in Home Audio.

wiring your 2 voice coils in Parralel, given they are both 4 ohm, will cause a 2 Ohm Load on your amp, EG: making your 100 Watt amp rated at 4 Ohm output 200 Watts.

To make a series wiring,

Start by plugging on end of your wire into the negative - input in the amp, then run it to the new negative wire to lets say left voice coil mounts Negative terminal, then lets run a short cable from the left voice coil positive + to the Right voice coil mount Negative -, then from the right voice coil mount positive + to the Positive + on the amp.

Your sub is now wired in series, and it's dual 4 Ohm voice coil, is producing a 8 Ohm load,

That being said, if you have a Dual 2 Ohm voice coil, series produces a 4 Ohm Load, and a Dual 8 Ohm voice coil would produce a 16 Ohm load ect ect.

Now with Parralel.

start by wiring your wire to the negative on the amp, then run it to the Left negative on the sub, then run a wire from your left negative on the sub to the Right negative (supposing your voice coil wiring mounts are opposite each other, you can also call it voice coil 1 and voice coil 2 if you like).
Now get a new wire, and run it from the positive on your amp to the positive on your left voice coil, then run another wire from the positive on your left voice coil to your right voice coil.

Now you have wired your sub in parralel, given that it's a Dual 4 ohm sub, you will have a 2 ohm load, or if it's a dual 2 ohm you will get a 1 ohm load,
and ect ect..

So what the hells the point of all this?

Imagine you want to run your Amp Bridged, and you can only run a 4 Ohm load, No lower.

Now lets go buy 2 12" Single voice coil subs.. you have 2 wiring options parrallel and series, one produces 8 ohm and one 2 ohm, but neither 4 ohm, unfortunatly to get the most power from your amp, you need a 4 ohm load.. so your stuffed! because you only have 2 4 Ohm Voice coils.

Now lets say you had 2 Dual 4 Ohm Voice coils.

Now we have 4, 4 ohm voice coils, we can run them in either series parrallel or parrallel series, and both will give us a 4 Ohm loading to our amp.

Rather than explain it.. get yourself a piece of paper out and draw up a series and parrallel circuit like i explained, and try to design a parrallel/series or series/parrallel circuit for your 2 subs.

with 4 4 ohm voice coils you all of a sudden have wiring options,

1 Ohm, 4 ohm and 16 Ohm loadings.

Keep this simple thing in mind, parrallel creates a reduced load, giving my amp more power, a series creates a increased load reducing my amps power.

This being said, Reducing your load, may increase your power to your amp, However your amp may produce ALOT more distortion, and it will loose some of it's control over the sub. Both of these things reducing their capability to produce nice quality sound, so always wire your subs to the reccomended loading, to avoid 1. Blowing your amp up and 2. creating crap bass.

Personally I run a 8 Ohm load, simply because the amp has alot more control over the subwoofer, and my bass become more accurate and dynamic, agreed it doesn't Pump and blow my windows out, but is just sounds plain nice and I'm not risking ruining both my sub and my amp.

the Higher the load, the less power you have, however the cooler and more effecient your amp runs, (draws less current)

Running a lower load than reccomended, might make your amp draw excessive current, which can damage your alternator, your batterys and even overheat the wiring your using if it's not good enough and finally damage your amp, if not do that first! not to mention overheat your sub voice coils and destroy your sub.

Keep in mind, this Highly depends on your Amp, and the type and design it is.
Some amplifiers, like D Class Subwoofer amps, are designed to run at 1 and 2 ohm loads. Some of the Older style A Class amps could cope with up to 1/4 Ohm loads, a feeble 25 x 2 amp could produce amazing power like 2000 Watts RMS! however that was the old days.. when 6 batterys and a 300 Amp alternator where required to get huge power!

Choose the amount and type of subs, to suit the amplifiers you plan to use.
and or vice versa, always make sure you have a big enough power system available for the subs and amps you want to run.

if you have anymore q's don't hesitate to email me.

regards
Juls
julsisere@hotmail.com
 
#6 ·
thanks for that well informed answer Juls. You've pretty much explained that to a tea.

I currently have a Alpine amp:

Alpine Amplifier Model # MRH-F255
Slim Line Design, Duo-Beta Circuitry,
Gold plated terminals 4-volt inputs, stable into 2ohms
Four Channel + Subwoffer Channel
First four channels are 35x4 watts RMS, 70x4 max, they
have a switchable (on/off) high-pass crossover that is
continually adjustable from 10Hz-50KHz.
The fifth sub channel is 80x1 watts RMS, 160x1 max
with a continually adjustable low-pass crossover
from 10HZ-50KHz

and I want to run a Clarion PA12-S 12" woofer in carpeted box. Specs are:

• Injected Polypropylene Titanium Coated Cone
• Single 50 m/m heat resistant Voice Coil
• Rear-Vented Pole Piece
• Foam Rubber Surround
• Large 40 oz Strontium Ferrite Magnet
• Chromed Metal Basket
• Suitable for sealed and vented Installation
• 600W Music Peak Power

Will my amp be sufficient enough to power this sub adequately?
 
#7 ·
looking around on the internet,

your amp actually puts out,

4 x 25 Watts RMS and 1 x 80 Watts RMS at 4 Ohms
4 x 35 Watts RMS and 1 x 120 Watts RMS at 2 Ohms
4 x 45 Watts and 1 x 140 Watts MAX.

not sure what the deal with this is, whats in your manual should be correct either way.

you didn't give me very good info on that but anyway.

You sub is probably ok on 80 Watts, I imagine it has a 4 Ohm voice coil, you can find this in your manual. I would suggest getting a ported box made specifically to give the best effeciency possible, you don't need power handling, cause you just don't have it, and the sealed box will really need more power than you have to sound good.

Get the box Tuned and ported to around 45hz if you can, while keeping in mind that you only have 80 watts on tap.

You can get box designs, or porting designs from leading car stereo shops for around $80.

If you need to make a new box, carpentry and cabinet making businesses usually charge around $60-90, then you can carpet it yourself or paint it.

As for if your Amp is capable of pushing your sub, in a sealed box.. I'd say No it is not. in a correctly ported and well designed box, specifically designed for effeciency and around 40-50 hz tuning freq, it should sound wonderful. The low side of this, is that your ported box will be HUGE and the sealed box will be small. The price you pay for good sound.

With your Low Pass, Suggest setting around 55-70 HZ Low Pass.

With your high pass on your speakers, set your rear stage around 100 HZ, to keep the bass out of the rear shelf, (to move your sound stage, and bass forward in the car) with the front speakers, try to run a 50-80 HZ high pass, the best way to set it, is to set your Head unit volume at 75%, with the Gain at 0, then crank the gain till you hear distortion then back off slightly, if it's not loud enough then increase your high pass from 50 hz upwards till you can get the volume you want without distortion in your front stage, however be reasonable, you can only expect so much with 25 Watts, try to choose speakers that only need that amount of power.. buying 300 watt speakers to run on 25 watts is false economy, the 300 watt speakers will sound CRAP on 25 watts, while 20 watt speakers will sound FANTASTIC on 25 watts.

Try to keep as much bass in your front stage as physically possible.

Your amp should be fine off the stock power system, I don't see any problems unless your running a old charade or something, as long as your alternator is 55-60 amps and your battery is fairly new, and good quality.
it should be sweet.

Regards
Juls
 
#8 ·
Thanks for that Juls.

To be precise, the system I want to run will be fitted in a Subaru Liberty Wagon (if that means anything). I will be running the standard speakers which consist of Clarion splits to the front and Clarion coaxials to the rear doors. Im not sure of the specs, but all Im looking for is better clarity and performance than what it has, as Im not entering ang db drags in the near future. :p

My head unit is a Sony CDX CA900 which 52x4w and will only power the rear door speakers where the amp will power the sub and front splits, obviously being careful not to overload them.

I was told doing it this way will provide better clarity but not necessarily increased volume of sound, which in the end doesnt bother me all that much. I only want to keep the standard speakers as I dont have the cash to upgrade at the moment. When I do I wouldnt mind going for some Bostons or JL's and upgrade the amp but it will all depend on cash and ease of fitment.

The sub is currently in an UNported box at the moment and I was told that it shouldnt make too much of a problem being in a wagon. But if it sounds really crap then I'll get it ported. Essentially I want good, solid bass which will play hip hop and RnB well in. If the system can handle that with the volume at 50% without distortion then I'll be happy.

Like I said, its not a comp car for the db drags, but it still needs to be clear and strong.

Will the above item previously mentioned acheive this?
 
#9 ·
Yes fer sure it should do,

you have 4 channels + a sub on the amp though,
I cannot see any reason at all to run the rear speakers on the head unit,
this is just another tuning headache.

Unless your amp is one of those amps that you bi Wire the 5th channel on,
in which case yes thats a good idea.

I think any sub, with that amp, will be an improvement over no sub at all.

and running the speakers on the amp, will make a massive difference in clarity and quality.

I would run the rears and fronts on the amps, so you can use the internal crossovers to cut some of the movement from the speakers, so you can push more volume out of them.

if you run the rears on the head unit, you may find you have to nearly fade it right out, because it will reach higher volume quicker than the front stage running on the amp unless you run ridiculous gain on the amp, which is bad because it heats the amp up quicker and adds distortion.

The problem you have is when you run a Amp you need to be at 75-80% volume on the head unit to get the full Voltage out of your RCA's, so your amp does not have to work so hard, the trouble with that is, that your head unit amp will be blowing the speakers up at that volume. And your front stage would still be quiet.

so take that into consideration.

regards
Juls
 
#13 ·
TIKFD6 said:
Hey Blueoval.
Have you got the dual vioce coil Subs yet?
You may be interested in these.
10" Dual voice coil Sub

I have heard these things go, and even if your running just one coil, the sound is very clean and responsive.
Im gunna get one for my car when i get my staff discounts.
:p
thanks for the link mate. I like the look of those subs, but I already have a deposit on the Clarion 12" PA-12S in box for $169. As I have mentioned above, Im not looking to beat any records, just want clear bass to play hip hop and RnB nicely.

I appreciate your thoughts.:hy:
 
#17 ·
dweaver44 said:
i have a quick question about dual 2 OHM loads..

if i have a pair of subs that are both dual 2 OHM, can i run them to my amplifier at 2 OHM?
Make sure you run them in series, ie connected in a loop. that willl make it equivalent to a 4ohm load. If you run them in parallel (from that one amp) then that makes it only a 1 ohm load, and therefore you will kill your amp.
 
#18 ·
mate this is getting realli complicated...

I wanted decent sound and amzing bass, so i decided to go with a nice head unit pioneer 9650+ the pioneer Class D 1000 amp + pioneer 12" 800max 400 rms sub. I was gonna leave my speakers stock


would this be ok?? it says on the site that the amp is 300rms at something and 500 rms at another. not sure wot this means.
also is it better to have a more powerful amp then sub, or the other way around. Me mates seem to have mixed opinions.
http://www.pioneeraus.com.au/car_entertainment/amplifiers/gmd510m/index.html
 
#19 ·
more power from amp = better. you can't kill the sub with a bigger amp because basically the sub determines the power output of the amp. (if u get me).

But your sub should sound pretty darn good with that amp.
stock speakers will sound better with a new head unit, but definetly can be improved on with new ones (obviously), but with the added bass from the sub you will be surprised how much better everything sounds.

I just had a look at the specs on your amp and sub. Basically, if you are running that one sub off your amplifier, the amp will be running at 4ohm mode. Which essentially means you will get a maximium of 300W RMS out of it. Note the 0.2% at the end of that figure in the specs stands for THD, or Total harmonic distortion. Meaning, when it is pumping out 300W RMS, it will only be distorting 0.2%, which is awesome.
 
#20 ·
Julsisere you really sound like you know your stuff without pissing in your pocket.Have you heard the Butler tube amps yet?If so what did you think?
I currently have Alpine DDDrives speakers and Alpine amps in my family car but tried the DLS A3 & A6 amps with Alpine speakers in my XF ute and have to say that I really like the DLS gear.
But as I'm yet to hear any Butler gear I'm not about to buy any until I've seen/ heard some in the flesh.
As for the dual voice coil over single debate,man you really just have to listen to all that you can and decide what you want by your own ears!I still have the same set of DDDrive subs I got 7 years ago and man they still sound great.But are currently advertised for sale looking for a new home.

I have my eye on a pair of subs I have wanted to try for a long time and now is the time.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top