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SomeGuyDude

Hey it's a "help me pick" thread, but don't worry I go

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The title was supposed to say "I got specifics", but apparently that was too long, LOL.

I know these are always awful, but I swear I've done my reading/searching and I'm not just saying "OMG U GUYS I WANNA SUB 2 POUND". I am, however, criminally indecisive so I might need a boost here.

I drive a 2010 Honda Fit. If you've seen one, you know there ain't a lot of space back there. I have a 12" JL w3 in a PWK designed box (built it myself, woo) and a 2.2cu ported box takes up this much space:

jt1YHl.jpg

So space is kind of a premium here. There's maybe an extra inch of depth I have but that's it, so nothing that'd need a big box (which is why I'm sticking with a 12, I'd need to strangle a 15 to get it back there). Plus to be 100 I'm kinda hoping I can still use the current box, LOL. It's a great enclosure, 2.2cu net tuned around 29Hz if my calculations were correct. If I really need to, sure, I can build another.

Again, it's a Honda Fit, which means the battery is the size of a deck of cards. So the biggest amp I'm heading for is one that's about 1000RMS. Any more and a simple Big 3 ain't gonna cut it. I'm not buying a new alternator, no sir. New battery maybe.

I'm not listening to symphonies and smooth jazz, nor am I just trying to burp shit out at 45Hz for competitions. I want a nice daily driver that'll extend down to 30Hz with authority and suit good ol' bass heavy music.

I do have the entire rest of the system upgraded, for the record. It's not stock with a sub. I'm Alpine Type R 6.5" components in all four doors plus tweets mounted up top, running off the amp on the right in that picture. They get loud as balls, which is good because much as I want my chest fluttering, I don't want the rest of the music to get drowned out.

The frontrunners are the PSI P1, Incriminator Lethal Injection, SSA GCON, and Fi SSD. I was about to pull the trigger on an RE Sxx, but apparently those are shit now, haha. Any suggestions?

Edited by SomeGuyDude

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It would help if you could tell us what you like and dislike about the W3 and why you are looking to change? What are you trying to improve? Based on your list there I'm presuming budget is around $200, give or take?

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I would leave the W3. You're not going to gain anything switching to any of the other subs. Perhaps a "different" sound due to psychoacoustics, but that's about it. You've got a great driver, although I think your enclosure is a bit on the large side for it.

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I'm chiefly looking for more output. The w3 sounds gravy but it definitely has a bit of a volume cap that the mids and highs don't. I don't want it to be farting along like my old L7 15 but it doesn't have to be flawless on the SQ side. Price is in the 200-250 area, yeah.

You really think none of the others are an upgrade from a w3? First I've heard that, honestly. The box was a PWK design, I gave him the full description. Sub/power/trunk/music, that's what came back. I dunno.

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I'm chiefly looking for more output. The w3 sounds gravy but it definitely has a bit of a volume cap that the mids and highs don't. I don't want it to be farting along like my old L7 15 but it doesn't have to be flawless on the SQ side. Price is in the 200-250 area, yeah.

You really think none of the others are an upgrade from a w3? First I've heard that, honestly. The box was a PWK design, I gave him the full description. Sub/power/trunk/music, that's what came back. I dunno.

Is that the sub and port facing to the rear

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Box is too big. And it was the boxes fault that your L7 sounded bad, mine doesn't have that issue.

You'll also gain more output changing the box or could if you chose that as your compromise.

As for the PWK designed, that is a bit laughable. A simple 4th order ported enclosure takes the math capability of a 7th grade Algebra C student. Laying out a "box" in wood is about 7th grade shop intro work.

And for pretty much all the drivers you listed, the math on the enclosure is a fail.

There are ways to get louder, but if your budget is $200 then it's time to address the box. Don't expect miracles though.

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Box is too big. And it was the boxes fault that your L7 sounded bad, mine doesn't have that issue.

You'll also gain more output changing the box or could if you chose that as your compromise.

As for the PWK designed, that is a bit laughable. A simple 4th order ported enclosure takes the math capability of a 7th grade Algebra C student. Laying out a "box" in wood is about 7th grade shop intro work.

And for pretty much all the drivers you listed, the math on the enclosure is a fail.

There are ways to get louder, but if your budget is $200 then it's time to address the box. Don't expect miracles though.

Boy you just know a way into a girl's heart, don't ya?

Anywhoo, I'm exaggerating the L7's SQ. It just didn't sound particularly musical. The box made it pound like hell and I enjoyed it while I had it.

How is the math on the enclosure a fail? Box recs from the websites:

PSI P1: Ported - 1.75-2.5 ft^3

SSA GCon: 2.00-2.50ft^3 @ 28-33hz (not optimal)

Fi SSD: Ported box: 1.8-2.5 cuft @ 33Hz

Lethal Injection: 1.75 cubes - 2.5 cubes, 25 - 40 Inches of Port, 28-35 Hz

Now unless my math is worse than I realized, 2.2cu at 30Hz seems to be right around where all four of those like to sit (a little low tuning for the SSD).

My budget isn't $200. I just ballparked that because on much beefier subs I'm gonna need to do way more than upgrade my amp. If I'm going up to a 1500RMS sub I'm not gonna be able to sail along on my stock electrical system.

And as for PWK themselves (they gave me the specs, I built), my understanding is they actually throw all the various parameters of the specific driver rather than just doing a simple "tune box volume X to frequency Y". Because I've done the math on box building before. If all they're doing over there is slapping a random volume into an equation to get a port length for a given frequency, yeah I coulda done it myself but I'd seen them recommended before.

Did I miss anything?

Edited by SomeGuyDude

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You could likely get 200 bucks for the W3. Try sub back port back. As for your options I say buy a Fi q and get a bigger deep-cycle. batt for the back. Do the Big 3 while you are at it and you should be good to go.

O and try to build the box your self

(design and build its not too hard)

...also your tuning is somewhat low. Try for around 32-35HZ for music honestly you will gain output and wont miss much at the bottom end.

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Sub and port are both back already. I thought that was kinda obvious in the picture.

You'd be surprised at the music that goes to 30 and lower too, LOL. Lot of rap these days seems to enjoy dipping down into the 20s.

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Sub and port are both back already. I thought that was kinda obvious in the picture. You'd be surprised at the music that goes to 30 and lower too, LOL. Lot of rap these days seems to enjoy dipping down into the 20s.

Yeah was meaning to say sub back port up :( in fact If I was you id sacrifice one of those rear seats as that opens a whole new world for you. I do understand that this is simply not a option for most people. With one seat down Ill do a a 18 4th order BP and with two seats down...well you get the point. (dreamz)

A box tuned to 32 will easily play a 30HZ or lower. If you set your infrasonic filter a wee bit below tuning before breakup becomes a problem you will be happy with it 99% of the time. I am not saying you should not do it. however in a car I will not tune lower then 30HZ personally. In fact these days I almost always go 32-35 for music.

Any how all the replies you see here will be options based on personal opinions. All you need to do is to pick one if you can not decide for yourself.

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Box is too big. And it was the boxes fault that your L7 sounded bad, mine doesn't have that issue.

You'll also gain more output changing the box or could if you chose that as your compromise.

As for the PWK designed, that is a bit laughable. A simple 4th order ported enclosure takes the math capability of a 7th grade Algebra C student. Laying out a "box" in wood is about 7th grade shop intro work.

And for pretty much all the drivers you listed, the math on the enclosure is a fail.

There are ways to get louder, but if your budget is $200 then it's time to address the box. Don't expect miracles though.

Boy you just know a way into a girl's heart, don't ya?

Anywhoo, I'm exaggerating the L7's SQ. It just didn't sound particularly musical. The box made it pound like hell and I enjoyed it while I had it.

How is the math on the enclosure a fail? Box recs from the websites:

PSI P1: Ported - 1.75-2.5 ft^3

SSA GCon: 2.00-2.50ft^3 @ 28-33hz (not optimal)

Fi SSD: Ported box: 1.8-2.5 cuft @ 33Hz

Lethal Injection: 1.75 cubes - 2.5 cubes, 25 - 40 Inches of Port, 28-35 Hz

Now unless my math is worse than I realized, 2.2cu at 30Hz seems to be right around where all four of those like to sit (a little low tuning for the SSD).

My budget isn't $200. I just ballparked that because on much beefier subs I'm gonna need to do way more than upgrade my amp. If I'm going up to a 1500RMS sub I'm not gonna be able to sail along on my stock electrical system.

And as for PWK themselves (they gave me the specs, I built), my understanding is they actually throw all the various parameters of the specific driver rather than just doing a simple "tune box volume X to frequency Y". Because I've done the math on box building before. If all they're doing over there is slapping a random volume into an equation to get a port length for a given frequency, yeah I coulda done it myself but I'd seen them recommended before.

Did I miss anything?

Comparing a spec that someone gave you to a number on a brochure is NOT the math I was referring to.

You stated a goal. Have a driver and then want to replace it in your box. If you'd actually have done the math then you'd know exactly why it's a fail. Ryan already told you why and I was empowering you to understand it yourself. Obviously I should have used a bigger spoon.

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Comparing a spec that someone gave you to a number on a brochure is NOT the math I was referring to.

You stated a goal. Have a driver and then want to replace it in your box. If you'd actually have done the math then you'd know exactly why it's a fail. Ryan already told you why and I was empowering you to understand it yourself. Obviously I should have used a bigger spoon.

Well which math are you referring to? I'm more than happy to chug away with number crunching on my own, but you can't just say "DO MATH" and then act like that was useful. What math was I supposed to do that showed me why it's a fail? And which part is the fail? You didn't empower anything. I much prefer learning to being given answers but if your answer is "lol math" then where am I supposed to go with that? What math did I do wrong?

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Wow.

To design a box the math is simple. Do the math.

Are you really questioning which math I'm referring to?

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Wow.

To design a box the math is simple. Do the math.

Are you really questioning which math I'm referring to?

Dude you keep saying the drivers don't match the box and I'm saying they do, and you're not even remotely explaining how you came about this conclusion. The sentence "And for pretty much all the drivers you listed, the math on the enclosure is a fail." doesn't actually mean anything. How is the math a fail? And what math are you assuming I did?

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Calculate the volume of the enclosure on your own. Account for driver and port displacements.

Is the volume accurate to the design?

Calculate the port area, and port length. Does the port area and port length actually equate to the expected tuning with regards to the calculated net volume?

Did the tuning appear to be correct, and if so, is the port area adequate for low port speed (reduce port noise and possible reduction in output)?

That's the simple math.

Edited by stefanhinote

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Yeah. I did all that. That's how I got the volume and tuning numbers (with an assist from http://www.carstereo...icles.cfm?id=31 double check the tuning). The non-port region is 12.5*22.5*14.5 = 4078.128, divide by 1728 and you get around 2.36. Port is 2.25x12.5 = 28.125" of port area, and it's about 30" long, so according to that jigger it's around 31Hz, my mistake. I got 30 by neglecting to account for sub displacement. 2.2cu tuned to 31Hz, roughly. What math is a "fail" here?

Edited by SomeGuyDude

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Yeah. I did all that. That's how I got the volume and tuning numbers (with an assist from http://www.carstereo...icles.cfm?id=31 double check the tuning). The non-port region is 12.5*22.5*14.5 = 4078.128, divide by 1728 and you get around 2.36. Port is 2.25x12.5 = 28.125" of port area, and it's about 30" long, so according to that jigger it's around 31Hz, my mistake. I got 30 by neglecting to account for sub displacement. 2.2cu tuned to 31Hz, roughly. What math is a "fail" here?

Presuming your math is correct, then you have about 25% more volume then what JL recommends on their site. I'm not saying that's good or bad, just noted.

Did you calculate port speed?

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Presuming your math is correct, then you have about 25% more volume then what JL recommends on their site. I'm not saying that's good or bad, just noted.

Did you calculate port speed?

Well first off this is like super basic geometry, so you can believe that my math is correct. :P

You're right about the box volume, and I thought the same thing, but again I put my trust in PWK on that one and assumed that he had his reasons for that suggestion. But one bonus of that is that it's a pretty standard box size/tuning.

Haven't calculated the port speed, but if memory serves the rule was always about 12sq inches of port area per 1cu foot of net volume (foot per foot, ne?) so we have that in the right region as well.

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Presuming your math is correct, then you have about 25% more volume then what JL recommends on their site. I'm not saying that's good or bad, just noted.

Did you calculate port speed?

Well first off this is like super basic geometry, so you can believe that my math is correct. tongue.png

You're right about the box volume, and I thought the same thing, but again I put my trust in PWK on that one and assumed that he had his reasons for that suggestion. But one bonus of that is that it's a pretty standard box size/tuning.

Haven't calculated the port speed, but if memory serves the rule was always about 12sq inches of port area per 1cu foot of net volume (foot per foot, ne?) so we have that in the right region as well.

No, port speed is dependent on port area, tuning, driver & power being applied.

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No, port speed is dependent on port area, tuning, driver & power being applied.

I know it's not an exact thing, but that's the ol' "rule of thumb" I'd heard before. Fired up WinISD (had to enter the w3 manually because it's a new model), and it gives me a port speed of .05, which is in green. So acceptable, according to the software.

Just outta curiosity, what specifically are we hoping to do with this? Best I can guess is figure out which driver maps best against my box (winner so far: DC Level 3, close tie with Lethal Injection).

Edited by SomeGuyDude

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Displacement creates output. If you want noticeably more output pick a sub with twice as much xmax as the W6. On paper without losses you will gain 3db in output.

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Well sure that's a factor, but I mean there's gotta be a lot more to it than that. The Lethal Injection has literally double the xmax (13 vs 26mm) and, well, it DOES map really nicely in WinISD, smooth curve with no weird peak. Hm.

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There is a lot more to it than that but it's kinda pointless to to get into it with out working the data.

For example a manufacturer has a 12" sub with an Re of say 2, a BL of 15, A moving mass of 350 grams, and an xmax of 30mm.

Now this manufacture recommends a ported enclosure with volume of 1.5-3 cubic feet tuned to 28-35 hertz.

The sub may graph out and work fine in an enclosure that's 1.5 feet tuned to 35 hertz or 3 cubic feet tuned to 28 hertz but it won't have enough motor force to control the moving mass to xmax in a 1.5 foot enclosure tuned to 28 hertz.

These numbers are arbitrary but it's one reason you can't use a broad ranged enclosure recommendation.

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