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Discussion Starter · #1 ·
I have a 12" Xtant in my car, it's been quite satisfactory and handles nearly 900 watts RMS, even though the recommended power is 500 watts RMS. I say nearly 900 watts RMS, because that's the size of my amp, and once or twice I have heard the sub bottom out slightly on bass-heavy tracks (and pretty much anything by the Beastie Boys!) Now I know I'm exceeding Xmax (the sub has at least 2.5" of travel before it bottoms) and overpowering the sub, and blah blah blah. Despite this, it plays very clean, loud, and accurate bass. Ever since I realized my amp was capable of bottoming the sub, I've been more careful, but I think I want to go bigger and better before long.

So here are my criteria for a new subwoofer, I've done a fair amount of research but it never hurts to tap the collective wisdom.
1) Subwoofer must handle at least 900 watts RMS, because that's what it's getting. 500 to 900 watt subs may also work, so long as they are severely underrated, such as my Xtant.
2) Subwoofer must meet or exceed 87 dB/1w/1m. Audiobahn-style ratings don't count. I want a sub that is at least as efficient as the Xtant, possibly more.
3) Subwoofer must be a good fit for my ported box. The box is perfect for my Xtant, it is a 2.7 CF net box @ 28 Hz and plays really low. Gross volume is 3.8 cubes if you care, and cross-sectional port area is 32 square inches. The box is too large to ever come out of my trunk, unless I get out the chain saw, and it is well-built, so I prefer to keep it.
4) Subwoofer must maintain good sound quality at high output. That's why I said SQ/SPL subs in the title.
5) Sub must be able to run at 2 ohms. So dual 4 ohm, dual 1 ohm, single 2 ohm, quad 2 ohm, quad .5 ohm, etc. I'm assuming it will be dual 4. This is so I can get all the juice out of my amp, I don't want to replace the amp.
6) Here's the clincher, the sub must be priced $300 or less. If I find one under $150, that would be amazing, but I'm willing to spend up to $300 if needed.

The first candidate on my list is an RE SX12D4, which is rated for 1000 watts RMS and and sports an 88.1 dB sensitivity rating. Please let me know what other subs might work, I know there must be more to choose from.
 

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What's the problem with your current sub?... IMO, you should have the power to bottom-out your subwoofer. If you can't, you have no headroom.
 

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Discussion Starter · #3 ·
What's the problem with your current sub?... IMO, you should have the power to bottom-out your subwoofer. If you can't, you have no headroom.
OK, I agree with that, mostly. Except to me, having headroom usually implies just that the amplifier has more power available than you are using, so you would never run it at or near 100% during normal listening. If I ran this amp on an even beefier subwoofer, such as the RE I mentioned, the amp would still have headroom and the subwoofer wouldn't bottom. Am I making sense?

I'm just thinking if I can find one that's a bit more efficient it would be nice. I'm already fighting an uphill battle since I'm running one 12 instead of two or more, and my aim is to be able to match most two-woofer systems in output, while demolishing them at SQ. It's a tough job, but somebody's got to do it!

So I love my Xtant, there's nothing wrong with it, I just want to explore my options. There are many people on this forum who know about more brands and models than I do, so if you know of a 12" sub that handles 900+ watts RMS, is efficient, and plays well in a large ported box, do let me know.
 

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Take a look at the FI.Q might be what you are looking for.
 

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looks like you did your homework.

imo/e same size subs do similar things on the same power, 10s sound like 10s, 12s like 12s etc etc, same cone area, same x max, etc etc. i dont think any sub available today will outperform your current sub on the same power by more than 5%.

my advice would be to see if you can make an adapter of some kind so you can mount a 15" sub to your current box. 40% improvement on same power< guess:blush:

that will give you more.

even adding another sub @ 12 " only gives you small gains (3db i think? on same power...or maybe no gain at all, maybe the math is 2 subs sharing same power = no gain, 2 subs sharing twice the power = 3 db? i forget )

anyway, step up to a 1000 watt 15 is my advice ...

just gotta make it fit :confused:

I have a 12" Xtant in my car, it's been quite satisfactory and handles nearly 900 watts RMS, even though the recommended power is 500 watts RMS. I say nearly 900 watts RMS, because that's the size of my amp, and once or twice I have heard the sub bottom out slightly on bass-heavy tracks (and pretty much anything by the Beastie Boys!) Now I know I'm exceeding Xmax (the sub has at least 2.5" of travel before it bottoms) and overpowering the sub, and blah blah blah. Despite this, it plays very clean, loud, and accurate bass. Ever since I realized my amp was capable of bottoming the sub, I've been more careful, but I think I want to go bigger and better before long.

So here are my criteria for a new subwoofer, I've done a fair amount of research but it never hurts to tap the collective wisdom.
1) Subwoofer must handle at least 900 watts RMS, because that's what it's getting. 500 to 900 watt subs may also work, so long as they are severely underrated, such as my Xtant.
2) Subwoofer must meet or exceed 87 dB/1w/1m. Audiobahn-style ratings don't count. I want a sub that is at least as efficient as the Xtant, possibly more.
3) Subwoofer must be a good fit for my ported box. The box is perfect for my Xtant, it is a 2.7 CF net box @ 28 Hz and plays really low. Gross volume is 3.8 cubes if you care, and cross-sectional port area is 32 square inches. The box is too large to ever come out of my trunk, unless I get out the chain saw, and it is well-built, so I prefer to keep it.
4) Subwoofer must maintain good sound quality at high output. That's why I said SQ/SPL subs in the title.
5) Sub must be able to run at 2 ohms. So dual 4 ohm, dual 1 ohm, single 2 ohm, quad 2 ohm, quad .5 ohm, etc. I'm assuming it will be dual 4. This is so I can get all the juice out of my amp, I don't want to replace the amp.
6) Here's the clincher, the sub must be priced $300 or less. If I find one under $150, that would be amazing, but I'm willing to spend up to $300 if needed.

The first candidate on my list is an RE SX12D4, which is rated for 1000 watts RMS and and sports an 88.1 dB sensitivity rating. Please let me know what other subs might work, I know there must be more to choose from.
 

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Discussion Starter · #6 ·
Take a look at the FI.Q might be what you are looking for.
Well, I appreciate the suggestion, I started searching and can't find one anywhere! I'm sure I'm just looking the wrong places, do you know anywhere they can be found online?

looks like you did your homework.

imo/e same size subs do similar things on the same power, 10s sound like 10s, 12s like 12s etc etc, same cone area, same x max, etc etc. i dont think any sub available today will outperform your current sub on the same power by more than 5%.

my advice would be to see if you can make an adapter of some kind so you can mount a 15" sub to your current box. 40% improvement on same power< guess:blush:

that will give you more.

even adding another sub @ 12 " only gives you small gains (3db i think? on same power...or maybe no gain at all, maybe the math is 2 subs sharing same power = no gain, 2 subs sharing twice the power = 3 db? i forget )

anyway, step up to a 1000 watt 15 is my advice ...

just gotta make it fit :confused:
Thanks, I've been doing this for about 6 years, though I'm a noob on the forum. My question to you is what then of efficiency ratings? Are they too subjective to trust?

Also, if I remember correctly two subs, if you double the airspace and leave the power the same else, and mounted in close proximity, can increase output by 3dB or more due to acoustic coupling. Double the power and you may gain 6dB or more over the original single woofer setup. Easier said than done.

As for trying a 15, I've considered it. The problem is that my box is only 15" tall, and that's the maximum height for my trunk. It would be a tight squeeze. I would consider a 12 with a longer Xmax, but usually this means greater MMd and therefore lower efficiency, so the output would be the same or less I fear. Or perhaps since I'm driving this one past Xmax, there would be a benefit of a longer voice coil despite efficiency ratings. :confused:

If it's true that I can't increase output by swapping for another 12, I may just keep this one around for the long haul. Anyone with ideas, keep them coming! Thanks!
 

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I remember reading that though efficiency may be lower in speaker A vs speaker B, speaker A may play more efficiently (louder with the same power) at a specific frequency range than speaker B.

Not sure where or who wrote it. but that whole X db's @1w/1m thingy is not always reliable. Especially for the whole low frequency reproduction.

Someone else jump in here and either add to with more geek speak or correct me.(the term geek speak is meant as a compliment regarding specific knowledge and is in no way meant to be considered derogatory.)
 

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Discussion Starter · #12 ·
I remember reading that though efficiency may be lower in speaker A vs speaker B, speaker A may play more efficiently (louder with the same power) at a specific frequency range than speaker B.

Not sure where or who wrote it. but that whole X db's @1w/1m thingy is not always reliable. Especially for the whole low frequency reproduction.

Someone else jump in here and either add to with more geek speak or correct me.(the term geek speak is meant as a compliment regarding specific knowledge and is in no way meant to be considered derogatory.)
I've wondered about that too. I can only imagine that if my Xtant with it's 13mm Xmax (we'll assume 26mm peak to peak) moves 2.5 inches (64 mm) peak to peak, thereby exceeding Xmax by a frightening 240%, a speaker with 85 or 86 dB sensitivity such as the Fi.Q and a 27mm Xmax would be under motor force twice as long, and possibly move 3 inches or more. It seems logical that this would more than compensate for a 1 or 2 dB difference in sensitivity at one watt! I know this speaker will see more than 1 watt!
 

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Your enclosure is a little big for a Fi Q12, and its sensitivity is a little under what you're looking for, but I'd agree that it's a great sub for both SQ and output.
Heck you could almost get a Fi Q15 in your box, and it's more sensitive than the 12. I used a single Q15 in my last car in 2.5 cubes sealed, off 920 watts it had enough output to crack my windshield where the rearview mirror mounts. The car was a 2005 Cadillac DTS, not some POS with a weak windshield. Not bad for an SQ sub in a sealed box. :D

The RE you're looking at would be a good candidate for you too, but I'd lean slightly more towards the Fi Q for SQ.
 

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Just because you have 900w doesn't mean you need to use all of it. In fact, you only think you are using 900w simply because it's there. This may be far from the case.

87dB sensitivity @ 900w = 90dB sensitivity @ 450w = 93dB sensitivity @ 225w

You get the idea. Efficiency will make up for a lot. The biggest limitation will generally be excursion anyways, not so much thermal handling. In this sense, you will look for a sub that has higher xmax/xmech then the Xtant sub.

Which Xtant sub do you have?

For a SQ/SPL mixed sub that fits your box well, I will point you towards Pioneer's PRS sub (TS-W12PRS). It's not 900w rms, not even half that, but sensitivity is high. It'll get very loud off very little power. The box you have is a very good fit for it too. Availability is...erratic. It may be hard to find. You'll really have to dig around to find one.
 

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Discussion Starter · #16 ·
Yes, I understand that efficiency makes a huge difference, but high efficiency often coincides with very low Xmax and power handling, in my experience.

Also, I'm using the full 900 watts RMS, the question is just how efficiently I use it.

My sub is an X1244, the T/S parameters are available in Xtant's archive pages.

It looks like the Fi.Q would work well, it's maximum box size is 2.5 CF, but I don't have the specs to see how well it would work with my particular alignment. Regardless, 2.7 CF is within 10% of 2.5, so I bet it would be fine.

My question is this: can a less efficient sub, such as the Fi.Q be louder at a given power simply because the VC sees motor force constantly rather than intermittently? In other words, increasing excursion but staying mostly within Xmax? I suspect my Xtant would move even farther if not for the mechanical limits of the sub.

Also, $400 is pretty steep, but the Fi.Q is less expensive and may be a very good value, I just wish I knew someone who had one so I could listen...
 

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Discussion Starter · #17 ·
So here's a list of suggestions so far:

RE SX12D4
Fi.Q 12 (dual 1 ohm)
Pioneer TS-W12PRS

Aside:

If my eyes aren't lying to me, the RE and the Fi have the same type of basket as a DIYMA 12, and are both probably built by TC Sounds. Also, it appears they probably all have the same mounting depth and voice coil. Does anyone else see where this is going?

I've seen RE SX12D4 recone kits for around $60. I know there are a few blown DIYMA 12s sitting around. How likely is it that cone, voice coil, and spider from an RE SX12D4 would be a perfect fit for a DIYMA 12? The new sub would be a DIYMA/RE hybrid, but I don't know if this would actually work. Any volunteers? Perhaps the end product would be more efficient than the DIYMA 12, and not have the cone-tearing problem.

Please post if you have ideas about the DIYMA/RE hybrid idea. I'm not too familiar with either sub, could this idea work?

Also keep the suggestions coming, I have browsed hundreds of subwoofers but in the last day or so I've found three excellent possibilities thanks to this forum. I appreciate the time you guys take, I'm doing my best to contribute to the forum as well.
 

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The hard part you have is trying to fit random subs to a specific box. That's basically doing things backwards.

Oh, I should add SI's Magv4, although it's not really SPL geared and SI does say it's not really designed for ported enclosures (although I don't get why...). I'll probably get to try one out in a month or so, but I've never heard it yet.

My PRS recommendation is on the fact that the PRS can get considerably loud with good energy and control. You'll just never use your 900w doing it though and if you try, you'll probably break the sub. I haven't really found a reason to own anything louder though. It's enough to drown out all the other sounds, and that seems like it should be enough. That was with less then 400w.

RE makes some really nice subs. I ran the SE and liked it a lot. Box size is about right but you might want it tuned a little lower. The SX is designed completely different though. I ran the SE in a 2.6 cu.ft. box tuned to 26Hz which was built for my PRS sub. The SX is meant for a completely different box size, just 0.60 cu.ft. ported, but the tune frequency would be ok. You'd just have to take up a ton of the box volume. The SE would be a little peaky, and its efficiency is crap, so it would need a lot of power to get loud and is only rated to 600w rms.
 

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Discussion Starter · #19 ·
The hard part you have is trying to fit random subs to a specific box. That's basically doing things backwards.

Oh, I should add SI's Magv4, although it's not really SPL geared and SI does say it's not really designed for ported enclosures (although I don't get why...). I'll probably get to try one out in a month or so, but I've never heard it yet.

My PRS recommendation is on the fact that the PRS can get considerably loud with good energy and control. You'll just never use your 900w doing it though and if you try, you'll probably break the sub. I haven't really found a reason to own anything louder though. It's enough to drown out all the other sounds, and that seems like it should be enough. That was with less then 400w.

RE makes some really nice subs. I ran the SE and liked it a lot. Box size is about right but you might want it tuned a little lower. The SX is designed completely different though. I ran the SE in a 2.6 cu.ft. box tuned to 26Hz which was built for my PRS sub. The SX is meant for a completely different box size, just 0.60 cu.ft. ported, but the tune frequency would be ok. You'd just have to take up a ton of the box volume. The SE would be a little peaky, and its efficiency is crap, so it would need a lot of power to get loud and is only rated to 600w rms.
Yes, I understand that's doing it backwards, I built the box and fully optimized it for my Xtant, planning to keep it forever. Perhaps I still will, I'm just exploring my options at the moment.

Really? 0.6 CF ported for an RE SX12D4? Here's RE's technical data, it suggests 2.0 CF @ 33 Hz is "optimal", but I may plug it into my spreadsheet later and see if I can go larger. http://www.reaudio.com/specs.html

Of the options listed, I'm leaning toward the Fi.Q, several of the T/S parameters match up with the Xtant, except that Xmax is about twice as long! I'm still looking into this, I expect there are more options, especially if I look at some more obscure brands.
 

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For the most part, manufacturers "suggested" box sizesare mainly for power handling. You want to run a gajillion watts? Make the box smaller. Want to increase efficiency? make the box bigger. Hoffmans law and all that.

The Mag would work for sure.
 
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