I will be buying some gear soon and all that I'm certain about, is that I'll be getting a Lanzar OPTI 1400D. This monoblock is good for 800WRMS @ 2 ohms, and well over 1000 at 1 ohm.

The dilema really comes down to 1 twelve or 2? Should I get one high powered 12? and run it almost to the extreme? Or get 2 lower powered 12's and stilll possibly have some spare power?

I'm looking at Alphasonik for my subs, or possibly Lanzar Heritage or OPTI.
The alphasoniks have a 12 that's good for 900wrms and others good for about 400 each. I can afford either one.

This istallation will be done professionally I think, with a fixed box behind the seats rather than my a pre-fab that I have stuck to in the past.

What do you think?

As I understand it, most car speakers are 4 Ohm meaning you'll need more than one to achieve anywhere near those figures: 2 in parallel to get the 800W and 4 in parallel to get the 1000W. Note too that these figures are almost always exaggerated, they were probably measured with 15% THD (Total Harmonic Distortion) or something crazy like that meaning you'll want to keep it low to maintain decent SQ. Not sure how or if that affects d00f d00f (at these kinds of power levels, that's all it is) tho.

Thanks for the prompt reply.

You obviously haven't heard of DVC - Dual Voice Coil?
The subs I'm looking at have DVC, two pairs of terminals, therefore you can wired them in parallel, giving the amp the impression that you have 2 four ohm subs.

But yeah, the big alphasonik i'm looking at will be able to pull the 800wrms, and as this is a monoblock - Class D - it will be able to pull some amazing figures.

Not exactly, but I did account for something like it in my original post when I said "As I understand it, most car speakers are 4 Ohm" I was trying to stress that even if I wasn't aware of their existence it didn't mean they didn't exist

Even taking DVC into account you'll still need two (assuming they don't make quad voice coil subs ) to get the quoted 1000W - something that may or may not be practical (which was what I was trying to get at in my original post). You're probably still better off going for less power (adding more amps if you want more than one sub) as distortion would still be a problem to closer you got to the upper limit irrespective of class.

I think I'll forget the fact that the amp is 1 ohm stable, and stick to 2 ohm. So we'll stick with 800WRMS.

I'm either going to buy one of the top of the range subs, which is DVC rated at 900wrms, or two of the lower class good for 400wrms.

Considering 1 12in mtx in a prefab ported box shakes my car a fair bit, what should I be expecting?

in my experience, 1 top of the line sub will give similar performance to 2 not so good subs.
adding a second will only increase bass by maybe 10 to 15%.

but 2 looks much cooler :p

I'm thinking that 2 could look cooler with the seats folded down - But maybe even cooler that only one sub is making ALL THAT NOISE!!!!

As far as a custom box goes - I've seen the pioneer AU XR6 with a box that left a fair bit of gap behind the seats, but was still totally sealed so fired directly into the cabin even with the seats up......

Any ideas?

i have one and it hammers

Sorry no input, though this is a very helpful thread! I had a couple of questions that I was going to ask in my own thread, though its been answered!

Good thread!

Actually some companies do make quad voice coils and you can even choose the voice coil configuration i.e. 4 x 2ohm coils, 4 x 1ohm coils or 4x.5ohm coils - But anyway thats not the issue.

Class D amplifers make much better power at lower resistences so you would want a 2ohm or 1ohm load to get the most from it, they also do not suffer the effects of heat anywhere as much as class A/B (most other amps) do. This is one of the reasons they are so much smaller in size as they do not need the larger headsink diserpation capability.

I would go with the best sub you can afford. The decision about 2 depends on a number of factors.

If you go with 2 subs (hence a lower resistence like 1ohm) as you decrease resistence you also reduce dampening factor which is degree to which the amp has control over the movement of the sub. I do not know the specs of the amp but typically dampening halves as inmpedence halves i.e. dampening factor of 800 at 4ohm roughly equates to 400 at 2ohm and 200 at 1ohm. Over 200 or 300 is considered ok and anything higher is better. If it's too low the subs will sound sloppy and will also have less protection.

Eg a series of short sharp doubble bass notes will cause the sub to sound washy instead of tight and punchy.

HOWEVER

As impedence reduces power often incresaes so it's a trade off. I would need to know the specs of the amp to be able to comment further but if it has a good dampening factor to start with then i'd go with 2 x 12's, and good ones can be had from $400 - $600 each, or more if you've got the cash.

That's the kinda info I was chasing.

Considering I'm getting the subs sent directly from the USA, I was going to get 2 x 12" 6000 series MTX subs, or go for some dual voice coil Alphasoniks or MTX to get right down to 1ohm.

The amp is a LANZAR OPTI 1400d and specs are available from lanzar.com

2 L7 kicker subs either 15 or 12" would hammer

i have 2 12" square subs by kicker and running them through 2500rms at 2 ohm and its so loud that i cant stand to listen for more than 10 mins lol

have fun selecting the subs

What made you go for the Alphasonik subs and Lanzar amps? Powerwise it's a good combination: amp max 900rms @ 2ohms, sub max 800rms @ 2ohms.

I've basically settled on a RF T10001BD (750rms @ 2ohms, 1000rms @ 1ohms) but haven't settled on a sub/s yet. I'm not sure what will be the optimal 12" to run at 2ohms.

X-rated - what made me choose? I saw 2 x 12in subs installed in a lexus is200 in a magazine, and they look awesome. They were in a custom perspex box so they showed off really well. Anyways, they were new to australia, and I still haven't found anyone that sells them. Specially up here. I'm actually getting these straight america. Same with the lanzar amp. My mate has a two channel vibe amp that runs his MTX sub, and it smashes you with bass. It's only about 225RMS..... making a picture here? The OPTI is very small. It's only about 36cm long, and same with the 4 channel vibe amp i'll be buying as well. They are both the same size.

I've decided on 1 only 12in alphasonik. Dual 4ohm sub, so I'll be running a 2 ohm load, producing 800wrms. Bassikly (sorry - bad joke) I'm going to get someone to install a sealed box, back slightly from the back of the seat, but still sealed forwards into the cabin, so I can leave the seats up. On the two angled panels, either side of the box, I'll have the amps mounted, possibly with blue neons throughout. Might even go for a perspex panel with neons in the box for effect.

Pricing ($US - you do the conversion)
lanzar OPTI 1400d - $289
alphasonik PSW612 dvc 800WRMS - $169
lanzar vibe421 4*100wrms $139

TOTAL = price that makes me smile

Fair enough. I'd be interested to see how it sounds with all that installed.

BTW, don't forget customs and taxes etc when importing that stuff. OCS is a good place to purchase from - but I see you know that already