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View Full Version : Custom enclosure stats (you want some made?)


Freq
02-19-2008, 03:42 AM
So I've been studying more about car audio lately (job + personal interest) and decided to start graphing various speakers and enclosures for my car. As much as I want to put a single 15" (or dual, but that just as impractical) I can't fit it in there without giving up either a clear path for the bass to enter the cabin or making access to my spare tire impossible. So I gave up and started modeling for 2 enclosures. One would go in each corner in the back of the trunk (against the back seats) and on either side of the long-stuff port. They'd be facing into the main trunk area, letting the pressure enter the cabin via the long-stuff port.

http://freq.auriplane.net/files/pictures/subs-freq.gif
Matching up single subs, dual subs, sealed, ported... I won't list all the sub matches (unless anyone wants them) since there's not a lot of point in it. They're all Polk subs, though. I'm liking the way red is looking. That's a pair of 12" SR124s in a 225L (8 cu. ft.) box. Does well in SPL, too.

http://freq.auriplane.net/files/pictures/subs-spl.gif
The best part is that this'll fit into my trunk and keep it (somewhat) usable. It'll cover up the spare wheel, but I think I can move that off to the wheel wells in the sides anyway.

Of course this is a dream system, but it's not impossibly far out. They're $425 a piece but I could get them both for less that $400, so I'm not dead floating just yet. Add in a custom box ($$ for wood and carpet), and a Kicker ZX1500.1 (whatever that costs), and I'll probably be the loudest, most annoying kid on the block. :] In the least attractive car, too.

If anyone wants graphs of their speakers in various boxes, speaker/box combos, whatever, I would be more than happy to pump some out. I just need box size, speaker type, box type, and if it's ported, whatever is relevant.

Lucky the Smiling Pirate
02-19-2008, 04:16 AM
heh, do me a favor and see what you can do with an spg555 2ohm powered at 1000wrms 2ohm stable.

Freq
02-19-2008, 04:27 AM
heh, do me a favor and see what you can do with an spg555 2ohm powered at 1000wrms 2ohm stable.

What kind of box and how big?

Freq
02-19-2008, 04:59 AM
http://freq.auriplane.net/files/pictures/boston-freq.gif
Blue: 80L (2.8 cu. ft.) ported enclosure w/ 20Hz tuning freq.
Yellow: 40L (1.4 cu. ft.) sealed enclosure.

http://freq.auriplane.net/files/pictures/boston-spl.gif
1000w @ 1m

Chris_R
02-19-2008, 09:30 AM
You will not need a 'path' for the bass from 2 15s to enter your cabin space.

Look into aperiodic enclosures if you really want 2 15s.

If anything you may want to remove the rear deck speakers completely... the extra pressure from the 2 15s will not be good for them anyway.

The red line in the top graph is nice! But damn, 8 cubic feet? the light-blue or white lines aren't bad really if the box is significantly smaller... Does that program take into account the in-car enhancement (I forget the actual term) that you get?

Freq
02-19-2008, 12:54 PM
The light blue and white lines are the sealed and ported 15s. I'm not really happy with their performance compared to the 12s, mainly because the 12s are a much higher end speaker. The advantage to going with the 15s, though, is they're half the price.

What I meant by 'path' was if I put the enclosure I first had in mind it would be sitting where the shelf area in the trunk, which would seal the most efficient ways of pushing sound into the cabin. My third idea, the one I graphed, was an enclosure that sits in the impression above the spare wheel well near the bumper, which is how I can get 8 cu. ft.

And just for the lulz, this is with the Kicker SoloX 18".
http://freq.auriplane.net/files/pictures/kicker-s18x-freq.gif

http://freq.auriplane.net/files/pictures/kicker-s18x-spl.gif
Purple is a single 18" SoloX in a ported box, 6.6L (which seems small but that's what the software is saying). The thick green one one is a dual 18" setup in a 13.9L box. Maybe I put some T/S data in wrong, but with the curves I want that's the size it's giving me.

Chris_R
02-19-2008, 01:10 PM
SoloX typically use smaller boxes. They mass-load the cone to make it act more like an isobaric arrangement. They typically need a lot of power too as they are as inefficient as an isobaric setup.

There are 2 ways to increase volume by 3 deciBels (+3dB effectively doubles the sound that you hear):
1) Double the number of speakers (given the same power to each - i.e. you had 1 10" sub getting 100W, now you have 2, each getting 100W)
2) Double the power going to your existing speaker(s). I prefer this method. Less upfront cost and less space sacrificed.

What are your goals for your system? That helps determine needs most often. I typically choose a single sub for my systems. You may have to spend more to get a really good sub, but it's worth it.

Chris_R
02-19-2008, 01:21 PM
I wish I had a sedan to play with... I have a pair of Coustic Bass Pumps I've wanted to play with for years.

No where NEAR what you're looking for, but would sound awesome in a moderate system.
http://www.coustic.com/support/PDFs/DR-328.pdf

Freq
02-19-2008, 01:31 PM
Half of the lines in my graphs are single subs, the other a dual setup. Those stats are all with the highest RMS power they're rated for. They'd obviously do more but I'd like to keep my subs A) alive and B) sounding nice. I don't really have a goal for the system yet, as I won't be able to build it for quite some time (summer project?). I'm just looking for good, flat response as low as logically possible with as much SPL I can afford. I'm not going to try and win any db drags since I building a system for 40Hz peaks is retarded, so sound quality comes #1, power comes #2. flat flat flat.

Chris_R
02-19-2008, 01:58 PM
If you want a great sounding system then I'd go with a single 12 - or a beefy-ass 10. Although, my favorite sounding systems were the old JL 10W6 triplets... or find some Image Dynamics subs.
IDQ were great... this guy has a pair in 2 different auctions: http://cgi.ebay.com/Image-Dynamics-IDQ12-Sub_W0QQitemZ260212566542QQihZ016QQcategoryZ18803Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem

I've had great luck with my Infinity Kappa Perfect 10.1, but I've heard a ton of horror stories about them as well.
My sub install:
http://forums.turbobricks.com/showpost.php?p=1282205&postcount=33

Freq
02-19-2008, 02:22 PM
Oh hell, if I had a wagon the bass would be crazy. I'd probably enter it in competition. But alas, my 744 will have to do. How does the speaker sound being covered up like that?

Chris_R
02-19-2008, 02:36 PM
You'd never notice the difference really. It was in a prefab box sitting on top of the cover before. If anything the bass got a little deeper.

Works like a champ and I can lock up most of my goodies! :rockon:

.t.i.m.m.y.240
02-19-2008, 02:52 PM
I may be reading wrong, but did I see that you had the specs up for an 8.0 cu.ft enclosure? That is insanely unnecessary, let alone the fact that you would no longer have a trunk! Just from the first graph alone, I would recommend using the setup that yielded the orange line. It has a much more accurate response at a lower decibel level. The purpose of design programs is not just to find how big of something will give you the most bass. Again, by your graphs alone half of your setups are producing levels beyond the threshold of pain! You wouldn't even be able to stand around your car with out irreversibly damaging your ears. Practically speaking, if you want just ridiculously obnoxious bass; just run an enclosure that yields 1.25 cu. ft per chamber and utilize a dual reflex bandpass system.

Chris_R
02-19-2008, 02:56 PM
Ewww... you said bandpass.

I'm biased against them because I've just seen too many poorly built setups... not to mention how much space they take up. But I'll give you this - a well designed/executed BP box is ok.

I now see the 'obnoxious' part of your statement... you had me worried for a sec there. :-P

.t.i.m.m.y.240
02-19-2008, 03:01 PM
Ewww... you said bandpass.

I'm biased against them because I've just seen too many poorly built setups... not to mention how much space they take up. But I'll give you this - a well designed/executed BP box is ok.

I now see the 'obnoxious' part of your statement... you had me worried for a sec there. :-P

+1 on your opinions good sir! I can't stand the things. the closest I want to go is a dual chamber enclosure sharing a single vent. And yes, people hardly ever take the time to construct them well, but if executed properly, they can be somewhat efficient.

Chris_R
02-19-2008, 03:07 PM
Are you an installer? If so, what store/shop?

.t.i.m.m.y.240
02-19-2008, 03:09 PM
I'm not an installer but I do work at the Best Buy in Gainesville in Car-fi. So it is kinda my thing. However, I am working on multiple certification programs (product specialist, BBY install and MECP Basic Install)

CAPT_BLOTTO
02-19-2008, 03:10 PM
i hate you

CAPT_BLOTTO
02-19-2008, 03:11 PM
I'm not an installer but I do work at the Best Buy in Gainesville in Car-fi. So it is kinda my thing. However, I am working on multiple certification programs (product specialist, BBY install and MECP Basic Install)

we work at the same job

plantationwalrus
02-19-2008, 03:29 PM
Kudos on the graphs, those are really helpful... In the next few months I'l be getting at least 1, possibly 2 SR104's (DVC) in 2 sealed boxes, possibly powered by a kicker zx1500.1. I'm not really a fan of Kicker's sound quality but their durability and sheer wattage output are pretty attractive. It's too bad Polk doesn't make an amp powerful enough for the SR's :(

IMHO 2 sr104's, even if they're sealed in the reccommended .8 cubic ft enclosure seems pretty excessive. Have you a tried graphing 2 lower powered 10's like the Momo 10" @ 300w as opposed to one 10" SR @ 700w? Alledgedly the SR has trouble hitting higher frequencies at higher volumes, simply because it's one driver that has an excursion of (arbitrarily) 2", as opposed to 2 drivers hitting an excursion of 1" each. Dunno iuf there's any truth to that though.

Oh if you haven't read it yet here's an independent review of the SR off of Polk's website, it was pretty interesting.
http://www.polkaudio.com/downloads/sr_review.pdf

EDIT: The Kicker zx1500.1 retails for $1199 btw. Just for sh1ts and giggles could you post what color line goes to which setup if it's not too much of a PITA? Curious minds must inquire...

Freq
02-19-2008, 08:54 PM
I'm at work right now; I'll post the speakers when I get home. Basicly they're various combinations of Polk's 12s, 15s, and eventually the Kicker SoloX 18s. I'm not an installer, either (as I hear sighs of relief), but I do work at a big-box store and as of late I've been in car audio. I'm not used to using a trunk so I really don't think that losing it would be that big of a concern. And I didn't make the box that large for any performance reason, just to see what it would do in a box so large. I'll make more graphs with the SR104DVCs. I've never been imperessed with the way bandpass boxes shape the sound, but i've never heard it, either. I think that, when I get the back of my car fixed, I should get some boxes made to fit in the wheel wells. That'd be somewhat pimp, I do believe.

kiwibrick
02-19-2008, 09:21 PM
I have 2 15's in my 760, I built the box INTO the boot, it takes up the whole righthand side of the boot, I can still get the spare tyre in and out (just) and the port through to the cabin is open.
With the boot closed it acts like a bandpass, and significantly increases the SPL in the cabin!

It's half pulled apart now but I will take some pic's when I get home and post them.

It always used to amuse me how things that you wouldn't even think could rattle would rattle in my car when I cranked it, I never actually cranked it way up because it just hurt my ears too much and it would make my cd stacker skip! :lol:

Freq
02-20-2008, 04:48 AM
Yellow = single SR124, 30L sealed
Green (thin) = single SR124, 80L port tuned @ 25Hz
Blue = dual SR124, 80L sealed
Red = dual SR124, 224.6L port tuned @ 22.21Hz
Dark pink = single MM2154DVC, 100L sealed
Orange = single MM214, 15.4L port tuned @ 19.97Hz
Pale blue = dual MM2154, 284.5L port tuned @ 6.67Hz
Light pink = single SoloX 18" (S18X), 6.9L port tuned @ 24.15Hz
Think green = dual S18X, 13.9L port tuned @ 23.01Hz

I've played with some of the numbers (mostly the orange one) so it's a little flatter and less awful. I'm tired and don't want to convert L into cu. ft., but most of those enclosures shouldn't be out of control. Just the pressure created by the two S18Xs. Look out for that shiat at the next Swede meet @ XXX. ;)

plantationwalrus
02-22-2008, 02:50 AM
I'm at work right now; I'll post the speakers when I get home. Basicly they're various combinations of Polk's 12s, 15s, and eventually the Kicker SoloX 18s. I'm not an installer, either (as I hear sighs of relief), but I do work at a big-box store and as of late I've been in car audio. I'm not used to using a trunk so I really don't think that losing it would be that big of a concern. And I didn't make the box that large for any performance reason, just to see what it would do in a box so large. I'll make more graphs with the SR104DVCs. I've never been imperessed with the way bandpass boxes shape the sound, but i've never heard it, either. I think that, when I get the back of my car fixed, I should get some boxes made to fit in the wheel wells. That'd be somewhat pimp, I do believe.

If you can get your hands on a couple I'd love to see how the SR104's perform compared to the SR124.

Thanks for the line deciphering... That red line is a god damn monster btw. If you don't mind me asking what big box retailer do you work at? I've been trying to find a place that stocks the SR subs but any place I go to stops at the Momo series and they want me to special order the SR's (which I can do cheaper at my work anyways).

I'm not an installer but I do work at the Best Buy in Gainesville in Car-fi. So it is kinda my thing. However, I am working on multiple certification programs (product specialist, BBY install and MECP Basic Install)we work at the same job




To the BBY guys, I'm in Roadshop aka Mobile at Circuit City in Modesto,CA... Good to see some other big box car audio guys on here.

lysolvolvo
02-22-2008, 06:34 PM
current shop project & demo car (for spring scikotics show):
REaudio MT15 dual 4ohm wired down to 2ohm w/ Earthquake PHD5000W... unrated power handling in a 5cu. enclosure should yield 145db+ at 3000watts, in a 2008 scion xb.

may post some picks of progress, the amp is too long to fit in back, so we are building a drop ceiling to fit amp, box is double walled & damped w/2 50lb bags of quickset concrete. no spare to speak of, but back seats will be functional.

mikes02ls1
02-22-2008, 10:47 PM
12W7 in a ported box to JL specs, with a JL Audio 1000/1 amp all in a 740 wagon.

Recommended Ported Enclosures
Subwoofer Volume
(net int.) External Dimensions
(Width x Height x Depth) Slot Port Internal Dimensions
(Slot Width x Slot Height x Slot Length) Port Extension
Length (EL) Tune to:
(Hz) F3
(Hz)
12W7-3 1.75 cu. ft. / 49.56 liters 22.75 in. x 15.5 in. x 15.5 in.
578 mm x 394 mm x 394 mm 1.75 in x 14 in x 24.0 in.
44 mm x 356 mm x 610 mm 8.5 in.
216 mm 36.7 31.5

Freq
02-22-2008, 11:02 PM
If you can get your hands on a couple I'd love to see how the SR104's perform compared to the SR124.
As soon as I get home I can build charts for those in different box sizes. Should be about a day.

Thanks for the line deciphering... That red line is a god damn monster btw. If you don't mind me asking what big box retailer do you work at? I've been trying to find a place that stocks the SR subs but any place I go to stops at the Momo series and they want me to special order the SR's (which I can do cheaper at my work anyways).
I work at the Circuit City in Puyallup (3736). I'd like to see some SRs in person, but I don't really look since I can't buy (and I can get them cheaper, as you'd you).

To the BBY guys, I'm in Roadshop aka Mobile at Circuit City in Modesto,CA... Good to see some other big box car audio guys on here.
Roadshop isn't my "home base", but I do work over there a lot. I'm from HE.

current shop project & demo car (for spring scikotics show):
REaudio MT15 dual 4ohm wired down to 2ohm w/ Earthquake PHD5000W... unrated power handling in a 5cu. enclosure should yield 145db+ at 3000watts, in a 2008 scion xb.

may post some picks of progress, the amp is too long to fit in back, so we are building a drop ceiling to fit amp, box is double walled & damped w/2 50lb bags of quickset concrete. no spare to speak of, but back seats will be functional.
Oh balls. Is 3000W peak power for that or RMS? All my graphs were RMS, but even at peak they'd still "only" be around +3db. Pics and pressure ratings would be amazing.

12W7 in a ported box to JL specs, with a JL Audio 1000/1 amp all in a 740 wagon.
I'll do my best once I'm home.

mikes02ls1
02-22-2008, 11:18 PM
Cool I left the specs for the box, that should help.

Freq
02-22-2008, 11:30 PM
How much power did you want going into the sub for the db level? Multiple power levels would work, too.

mikes02ls1
02-22-2008, 11:37 PM
How much power did you want going into the sub for the db level? Multiple power levels would work, too.Well I had my gain at 3/4 so I say 750 watts, sub level was at 15 on my Alpine HU, 0 guage on my + and - SVR 1000CCA battery.. Same setup I had in my old 00 Civic Si coupe hit a 149.1 on a old meter back in 03...

mikes02ls1
02-27-2008, 12:19 AM
Hopefully this wasn't a hard one...

Freq
02-27-2008, 02:50 AM
Hopefully this wasn't a hard one...

Heh, oops. Crazy few days. I'll get it up in a little bit.

Edit: While looking at the T/S specs for the 12W7 I saw this at the bottom...
** Efficiency (1W/1m) is not an accurate indicator of a subwoofer’s output capability and should not be used as a comparison to other subwoofers to determine which one is “louder”.
WTF? I'm pretty sure that a 90db speaker is a LOT louder than a 86db speaker (phht, like 2x the volume @ same wattage is important).

Edit 2:
http://img214.imageshack.us/img214/8766/12w7splnu0.gif
SPL vs Frequency

http://img442.imageshack.us/img442/8162/12w7gaintv7.gif
Gain vs Frequency

You were hitting >140 with that setup?? Just 1 woofer?