krayziep5

I already have a sub chosen out but I'm not 100% sure of how DVC subs work. The sub I have in mind is the IDQ12V.2 D4. All of the specs are at http://www.imagedynamicsusa.com/webs...idq12d4v2.html
I'm pretty sure that this is a 4 ohm sub but under nominal impedance on the webpage above, it says 2/8 ohm. I'm probably going to get a mono or 2 channel amp to run this sub but I don't know what kind of amp to look for whether it be stable down to 2 ohms or 4 ohms. Can anyone with experience with DVC subs help me out?
Thanks!

Maz94Protege

DVC (Dual Voice Coil) subs need same amount of power to each coil. U can achieve this by having 2 amps or Bridging the sub.
Bridging the sub is this....

One Side +(posi) goes to the Positive Term on the Amp
The other sides - (neg) goes to the Negative terminal on the amp.
Now u have a - on one side and a + on the other with no wire attatched. Place a wire to connect to the open Terminals. so that the open Negative (-) on the sub is Linked to the open Positve (+) on the other side of the sub.

This is Bridging the sub in parallel. A series is 2 Pos wires (one on each side and 2 Neg wires One on each side. This requires a more powerful amp.

The Bridgeing in Parallel, gives u more power to ur sub.

Ill try to get a pic made of what it looks like.

hope i helped u out

krayziep5

How does wiring in series or parallel change the impedance of a sub?

onehawaiian

dude, if you are going for sound quality (sq), get a nice custom box made w/2 terminal cups and wire each coil to the amp (assuming it's 2ch). you should get a nice 8ohm load and sweet sounding bass. you'll still get loud (not competition loud tho) cause you're in a hatchback, so don't worry about your spl.

hihoslva

Sorry hawaiian - I gotta diasgree.

I would say to wire the sub to 2 ohms, and get an amp that is stable down to 2 ohms when bridged. Generally, you'll need a Class D amp for this - rarely are A/B amps stable to 2 ohms bridged. And if you wire the sub to 8 ohms, you'll need an amp about twice as powerful to run it properly, which can be a LOT more money to spend. If the sub takes 300 watts RMS (for example) you'll need a class A/B amp that puts out 600 watts (because they are almost always rated into a 4 ohm load) to make 300 at 8 ohms. But a class D amp, you can run down to 2 ohms and it will make the advertised power (generally, class d amps are rated driven into a 2 ohm load.)

Wired in parallel will give you a 2 ohm load, and in series gives an 8 ohm load with this sub. If you want to know how or why it works, do a web search for Ohm's Law and you'll get more info thatn you'll know what to do with - but it is basic elecrical physics of impedance.

Look at the JBL series amps - the class D's are stable down to 1 ohm, and put out max power at 2 ohms. The 300.1, 600.1, and 1200.1 are all excellent values for great power.

~HH

onehawaiian

hiho, that's true (i got my jonah's wired at 2ohms right now), but my powerplant got plenty loud with each coil wired to the amp, and it sounded really good too. i was just suggesting for a daily, and the hatchback will pick up any slack for spl.

wiring your sub at 2ohms makes the amp work harder (unless you're using class d!) and in the long run may wear down lesser amps. it's your call tho, but 4ohm/dvc gives you pretty good options for a single sub, as you can bump harder (2ohm) or sound cleaner (8ohm). but either way, your idq's will be loud enough for ya.

however, from experience, i found spl properties to be very addicting. even tho i was going sql, and had some emphasis on sq, i found that when ppl were around, i always turn up the bass and let them know the p5 funk will pound.

either wiring options will be fine tho.

hihoslva

This is SO true! I started out wanting a little "filler" bass, buying a cheap-*** Kenwood sub in a cheap pre-fab box and flea-market amp. Well, that **** has ballooned into having one 500 watt RMS Rockford sub in the car (that I'm NOT happy with!?!?) and having two 275 watt RMS Infinity's sitting in my living room until I get the time to fiberglass a new subwoofer enclosure. My system went from deck power and a cheap sub amp (probably 250-300 watts total) to two amps, soon-to-be dual subs, with a total power of about 700 watts, and the potential to be up to about 900 if I wired my non-sub amp to 2 ohms/side.

WTF???

~HH

krayziep5

Does the box really affect sound quality that much? If I find a box within the recommended volume, wouldn't that be just as good?
Also for the ohm law thing. Does that mean if I got a 2 ohm DVC then it could be wired to 1 ohm or 4 ohm but not 2 ohm?

pollax

The box makes a huge difference in sound. If you find a box that has the recommended volume it should work fine but you need to remember that box construction also has a lot to do with sound quality. So get a well made box at with the correct volume and you should be all set.

Actually a 2 ohm DVC sub coule be wired as 1/2/4 ohms. You can run one coil at a time on a DVC but that really isn't recommended. It will work but you will not get the full potential out of the sub. It would be more of a temporary fix such as if your present amp can't handle the lower impedance and you are waiting to replace that amp with something more capable.

onehawaiian

3/4" mdf is the best all around for sub enclosure's. normally, recommended volume would be great, but sometimes you want a little more out of your subs, so going bigger could be an option.

as for ohm law, yes. a single 2ohm dvc sub will produce 1 or 4 ohms.

hihoslva

No for the first, yes the second.

The box you use has EVERYTHING to do with sound quality. The best sub in the world can sound like **** in a poorly built box, while a cheap-*** sub can sound pretty damn good if the box is excellent and perfect.

Some pre-fab boxes are just fine - but I would absolutely stay away from anything made with particleboard - you want MDF (medium density fiberboard). Birch plywood and marine plywood are rumored to be the best, but MDF is excellent. A box with particleboard, or one that is poorly built (leaky, crappy seams, etc.) will never sound good. You want the box the flex as little as possible - you'd be surprised how much force a sub can exert on a sealed enclosure. And a ported enclosure needs to be built to exact specifications in order to have good SQ - the effect is even moreso with a bandpass box - most pre-made bandpass and ported boxes are terrible - they are not built to suit the sub you are using, and are not tuned properly at all - the result is muddy sound, sloppy bass, and often low output.

Sealed boxes are the easiest to make, because solid construction and proper airspace are really the only concerns.

Your summary of DVC subs is correct though - a DVC 2 ohm sub can only be wired to present a 1 ohm or 4 ohm load (unless you add more subs, then the options change).

~HH

pr5owner

click my www button i have an explination of how i wired my DVC subs

krayziep5

Thanks for all the help everyone! I should have everything installed by the end of today

onehawaiian

dude, did you go to security sound and systems? i think that's their name... i keep getting them and the magazine mixed up. good luck on your system. y'know, if you bought it from them, just ask which wiring option would be best for your needs. i trust those guys to give good suggestions.

krayziep5

I got it from security and sound systems for $199.99. I got the 4 ohm one and I wired it down to 2 ohms on a Concept amp. I only listened to it for about 30 minutes, but so far it sounds great!