RMS on subs, how is it mutli. Options

[JFrost9]

Ok, so im still shopping for subs, and i assume ive figured everything out, the good brands the bad brands, the way they are measured and all the other stuff. Im still confused on one thing though. If i was to buy lets say an ALPINE SWR-1222D 12" DVC 2 Ohm 1500W SUBWOOFER. Its around 500 RMS. Heres my question... if i was to buy not 1, but 2 instead, how would that change the RMS and everything else? i thought it would just mean that i would have 1000 RMS, but that doesnt seem to be the case. Ive been searchin around to try and figure out how it works, but i figured it would be easier to ask.

[WannabeGT4]

Check it out:
http://mobile.jlaudio.com/support_pages.php?page_id=145

It all depends on what your amp can provide and how you wire the subs.

[JFrost9]

ok well these diagrams explain pretty well how to wire them, but it doesnt seem to explain my question... I understand there are different ways to wire them, but i just want to know if getting 2 subs will make a big difference or not, i have a mono D 1500 watt sub...
Rated Power @ 4 ohm: 425 x 1
Rated Power @ 2 ohm: 800 x 1
Rated Power @ 1 ohm: 1200 x 1

This post has been edited by JFrost9: Sep 13, 2005 - 8:22 PM

[ShadowFX]

if you get 2 subs, therefore effectively doubling the power, you should gain about 3dB, given the best conditions. its not really noticeable. i have two subs mainly because I got them for a great deal, and for show factor. for daily listening, im sure you'll be hard pressed to tell the difference between one or two subs, especially at the low frequencies.

This post has been edited by ShadowFX: Sep 14, 2005 - 8:40 AM

[WannabeGT4]

2 DVC drivers with Voice Coils in Series / Parallel
Connecting the two voice coils of each driver in series (+ to -) and the drivers themselves in parallel (+ to +, etc.) will result in the following impedances:
Dual-6 Ohm Subwoofers: 6 Ohms
Dual-4 Ohm Subwoofer: 4 Ohms
Dual-2 Ohm Subwoofer: 2 Ohms
Dual-1.5 Ohm Subwoofer: 1.5 Ohms

If you have two dual 2 ohm voice coil subs wired in Series / Parallel the amp will be seeing a 2 ohm load. In most cases the output of the amplifier is determined by the amount of resistance it sees from the subs.

So if you have an amplifier rated at:
425W x 1 @ 4 ohms
800W x 1 @ 2 ohms
1200W x 1 @ 1 ohm
Each sub would be seeing about 400W.

But if you had an amplifier rated at:
425W x1 @ 4 ohms
850x1 @ 2 ohms
1275W x1 @ 1 ohm
Each sub would be seeing 425W. Essentially doubled.

Which is why I said it all depends on what the amplifier can provide.

EDIT: ShadowFX is right. You probably won't hear that much of a difference if you're powering two subs at 400W compared to one sub at 425W. However, if you have a more efficient amp and power them both at 425W @ 2 ohms the difference will be a bit more noticeable.

This post has been edited by WannabeGT4: Sep 14, 2005 - 9:14 AM

[JFrost9]

well im just goin for sound, im not worried about how it looks, i just love music... so i guess 1 sub it is, this will be good, ill get to spend that extra money on some speakers. thanks alot for your help guys!

[Lopakasweet]

id suggest buying one of these for clear but yet verry loud bass
http://www.ddaudio.com/dd/amp/C4.asp
i have 1 12" DD 9500 series with a 1500rms watt amp sounds great and i kill alot of people on the street that wanna challange me lol check it out
ohh yeah if you wanna go spl way you could strap like 3 more amps to it to make it push about 4500-5000watts but i dunno whwat you looing for

This post has been edited by Lopakasweet: Sep 27, 2005 - 11:29 PM

[snadman]

Don't buy a used Type R...get a new SWR1242D it's a 500W RMS DVC 4 Ohm. Then pickup the Alpine V12 M-605 amp and you're set. Muah, sounds beautiful.