# DIY sewer sub. 6" of DIY powah!



## Lazzer408 (Feb 19, 2010)

No woodwork skills needed. Just a drill and a saw. Anyone could build this with hardware store parts.

6" drain PVC, 1-1/2" PVC, a 1-1/2 to 2" bushing, 2" coupler, and two 6" caps.

The coupler is used to hold the bushing in the 6" cap from the back side. 6" PVC is 15" long. Port is 10" long. File the lip off the inside of the bushing so the port can be pressed into it from the inside. Port lenght can vary from a few inches to a foot depending on the sub used and the tuned frequency. Tune it then glue it.

My "subwoofer" was just some el-cheapo 6" speaker I had laying around but it's loud enough to fill in the missing low end of a stock Mecury SUV.  Hits as low as the 12" that came out just not as loud.


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## Lazzer408 (Feb 19, 2010)

My camera made this sound boomy then my battery died but you get some idea of it's sound.

http://www.youtube.com/watch?v=774wfjqcAho


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## Lazzer408 (Feb 19, 2010)

I found an old Altec Lansing computer sub in the basement and it wound up being 4ohms. Looks better and gets much louder. I need to record this thing somehow. I'm actually impressed.


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## Lazzer408 (Feb 19, 2010)

New vid of the Altec Lansing but it only lasted about 15min. It didn't burn up. The glue on the bobbin was dried out and failed. =( But I got another video of this one. Check it out.

http://www.youtube.com/watch?v=Jw24EsCpuP0


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## Wile E (Feb 19, 2010)

Bleh. How can you stand the sound of tube boxes? They are terrible. Although, I have to admit, very ingenious idea if sound quality is not your main concern.


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## department76 (Feb 19, 2010)

there are some kickass builds that can be done with sonotube, with real subs...


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## Lazzer408 (Feb 19, 2010)

SQ is my concern and I spent 2 hours tuning the enclosure with a signal generator. 

EDIT - Being a cheap bastard is the other concern.


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## theonedub (Feb 19, 2010)

What is the enclosure tuned to? I would like to try this for s&g's with a decent 8" sub instead.


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## DonInKansas (Feb 19, 2010)

We were doing this stuff in high school with 5 gallon paint buckets and 12s bumpin' Eazy-E.


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## Lazzer408 (Feb 19, 2010)

DonInKansas said:


> We were doing this stuff in high school with 5 gallon paint buckets and 12s bumpin' Eazy-E.



With a signal generator, spectrum analyzer, and a knowlage in acoustics, harmonics, and musical scale? Unlikely.


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## Lazzer408 (Feb 19, 2010)

theonedub said:


> What is the enclosure tuned to? I would like to try this for s&g's with a decent 8" sub instead.



It's tuned to C-1 aprox 33hz


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## AsRock (Feb 19, 2010)

Love the idea but 1st that speaker has no chance of creating any decent sound compression in that tube. Try digging up a long throw woofer.

Plastic is another issue well that and being thin too.


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## Wile E (Feb 19, 2010)

Lazzer408 said:


> SQ is my concern and I spent 2 hours tuning the enclosure with a signal generator.
> 
> EDIT - Being a cheap bastard is the other concern.



By SQ, I mean flat, accurate response. Only sealed will do.

But like I said, if the tuned tube box is your sound, this is a great idea.


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## Lazzer408 (Feb 19, 2010)

AsRock said:


> Love the idea but 1st that speaker has no chance of creating any decent sound compression in that tube. Try digging up a long throw woofer.
> 
> Plastic is another issue well that and being thin too.



The PVC is pretty solid for what it is. Yeh that first speaker was just something I had laying around. It's built better then the Altec Lansing, that disintegrated, but didn't perform as loud as the Altec. Mostly in part to the Altec being 4ohm and the 'generic' being 8. The amp is under a plastic cover in the truck and I couldn't adjust the gain easily. A longer throw woofer is on the way. Rated 150w RMS -if- I can keep the excursion to a minimum.



Wile E said:


> By SQ, I mean flat, accurate response. Only sealed will do.
> 
> But like I said, if the tuned tube box is your sound, this is a great idea.



I have 2 Cadence 10s in an acoustic suspension enclosure in my SVX. They sound much better I agree. The truck in the vids isn't even mine. It's my friend who runs a dog adoption agency and taking her 12" sub in and out, to put in dog transport cages, was too much work for her. I was aiming for fast, simple design, high output, while maintaining a good sound quality. It's hard to fill an SUV with sound from a single 6" sub that would fit where it does. Have you ever heard a decent set of 6x9s (that's a oxy) in a Caprice trunk deck that almost trick you into thinking there's a sub in the trunk? This single 6" has roughly that output.

Oh and Wile, You know damn well there's no such thing as flat response in a vehicle. lol


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## department76 (Feb 19, 2010)

Lazzer408 said:


> The PVC is pretty solid for what it is. Yeh that first speaker was just something I had laying around. It's built better then the Altec Lansing, that disintegrated, but didn't perform as loud as the Altec. Mostly in part to the Altec being 4ohm and the 'generic' being 8. The amp is under a plastic cover in the truck and I couldn't adjust the gain easily. A longer throw woofer is on the way. Rated 150w RMS -if- I can keep the excursion to a minimum.
> 
> I have 2 Cadence 10s in an acoustic suspension enclosure in my SVX. They sound much better I agree. The truck in the vids isn't even mine. It's my friend who runs a dog adoption agency and taking her 12" sub in and out, to put in dog transport cages, was too much work for her. I was aiming for fast, simple design, high output, while maintaining a good sound quality. It's hard to fill an SUV with sound from a single 6" sub that would fit where it does. Have you ever heard a decent set of 6x9s (that's a oxy) in a Caprice trunk deck that almost trick you into thinking there's a sub in the trunk? This single 6" has roughly that output.



some explanation helps lol   spectrum analyzer, eh?  where'd you find that?  i wouldnt mind a cheap portable oscilliscope for dialing in amp gain, but what do you think you need a spectrum analyzer for? haha.

i wouldnt be concerned about using PVC, that stuff is pretty damn rigid.  good call on venting that also, you'll need the extra 6dB since that thing is so tiny.  i'd be more concerned about throwing random speakers in the box, shooting in the dark for good performance.  t/s parameters and proper analysis is a must for a successful project...

to Mr. Qtc of .707: let's be serious here, a 6" in a sealed box wouldnt do much.


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## Lazzer408 (Feb 19, 2010)

department76 said:


> some explanation helps lol   spectrum analyzer, eh?  where'd you find that?  i wouldnt mind a cheap portable oscilliscope for dialing in amp gain, but what do you think you need a spectrum analyzer for? haha.
> 
> i wouldnt be concerned about using PVC, that stuff is pretty damn rigid.  good call on venting that also, you'll need the extra 6dB since that thing is so tiny.  i'd be more concerned about throwing random speakers in the box, shooting in the dark for good performance.  t/s parameters and proper analysis is a must for a successful project...
> 
> to Mr. Qtc of .707: let's be serious here, a 6" in a sealed box wouldnt do much.



I've built many boxes based on the math and had them sound like total garbage. Many of these speaker manufactures don't base their TS off SQ performance but rather off max power handling with least distortion for db performance. How do you think they rate a speaker to handle crazy wattage that might as well be a horsepower rating? They stiffen the suspension and recomend a tiny box so that speaker 'chokes' and wont over-excurt. I don't mean to imply they state TS parameters for anything other then what they are but look at how some of these speakers are built. Does it really take 2000w to move a 10 gram cone? Speakers need a power to weight ratio.

Besides, I didn't build this to show off any mad enclosure building skills or anything. I just did it quick and easy and figured I'd post it for others to try. I just happened to be very impressed with it's sound for what it was.


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## selway89 (Feb 19, 2010)

Good work man, although I prefer the sound of an infinite baffle instead of a tuned ported sub.
I did some work over the summer on a sub-woofer for my pc and hifi gear.
http://forums.techpowerup.com/showthread.php?t=101818
Sounds fantastic no matter what the music is, nice deep bass with a tight response. 
Im glad I went with the Mission speaker as it matches my M30i speakers, I just copied the enclosure volume of the subwoofer the driver is designed for.


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## Steevo (Feb 19, 2010)

I like unsealed boxes, but I use multi-compartments, and long ports between them, andthen one large tuned port.

Add that onto a good set of speakers and you can get some awsome kicks and some nice rattle.


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## Solaris17 (Feb 19, 2010)

Lazzer408 said:


> With a signal generator, spectrum analyzer, and a knowlage in acoustics, harmonics, and musical scale? Unlikely.



thats a pretty sweet call out. makes you look wicked cool considering he didnt say anything about going about the project in a pro manner


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## Lazzer408 (Feb 20, 2010)

selway89 said:


> Good work man, although I prefer the sound of an infinite baffle instead of a tuned ported sub.
> I did some work over the summer on a sub-woofer for my pc and hifi gear.
> http://forums.techpowerup.com/showthread.php?t=101818
> Sounds fantastic no matter what the music is, nice deep bass with a tight response.
> Im glad I went with the Mission speaker as it matches my M30i speakers, I just copied the enclosure volume of the subwoofer the driver is designed for.



Woah wtf is up with those suggestions on that link? Who the hell had you put 2.6k resistors in series with the sub? = fail. Bet that didn't work too well eh? lol Paralleling an amp's outputs like that isn't a good idea. Even with both inputs being driven mono your asking for it. Hope that drawing is line-level and with a powered sub.



Solaris17 said:


> thats a pretty sweet call out. makes you look wicked cool considering he didnt say anything about going about the project in a pro manner



Compairing my project to a sub stuck in a paint bucket is both belittling and insulting. It doesn't look very impressive I'll give you that but c'mon.


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## selway89 (Feb 20, 2010)

Lazzer408 said:


> Woah wtf is up with those suggestions on that link? Who the hell had you put 2.6k resistors in series with the sub? = fail. Bet that didn't work too well eh? lol Paralleling an amp's outputs like that isn't a good idea. Even with both inputs being driven mono your asking for it. Hope that drawing is line-level and with a powered sub.



Yeh I know, don't worry I haven't done it like the initial drawings. Main speakers are driven normally and the low level headphone out is then connected to the RCA on the sub amp. Works a treat.


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## DonInKansas (Feb 20, 2010)

Lazzer408 said:


> With a signal generator, spectrum analyzer, and a knowlage in acoustics, harmonics, and musical scale? Unlikely.



Where in the original post did you say anything about these things?  Oh, that's right, you didn't.  Drill, saw, PVC pipe, enjoy.  That's all I see.


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## Wile E (Feb 20, 2010)

Lazzer408 said:


> Oh and Wile, You know damn well there's no such thing as flat response in a vehicle. lol


lol. You won't hear any arguments out of me about that, but I like to try to get it as close as possible.


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## Lazzer408 (Feb 20, 2010)

Wile E said:


> lol. You won't hear any arguments out of me about that, but I like to try to get it as close as possible.



Have they come up with an inexpensive device for per-speaker phase adjustment yet? I have this huge null in my mid-bass in the SVX. Drives me up the wall.  I've double and tripple checked polarity because it sounds like something is out of phase but it's all wired correctly.


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## Wile E (Feb 20, 2010)

Lazzer408 said:


> Have they come up with an inexpensive device for per-speaker phase adjustment yet? I have this huge null in my mid-bass in the SVX. Drives me up the wall.  I've double and tripple checked polarity because it sounds like something is out of phase but it's all wired correctly.



No they haven't. You're SOL there, tho I bet you could come up with something. . You positive it's not a simple crossover issue?

And what's this about an SVX? Still have the MX3 and 5's?


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## Lazzer408 (Feb 20, 2010)

DonInKansas said:


> Where in the original post did you say anything about these things?  Oh, that's right, you didn't.  Drill, saw, PVC pipe, enjoy.  That's all I see.



I did all the hard work already that's why there's no info about it. I'm not designing this for any reason other then to give out ideas that work. I never claimed it was acoustically perfect but is sure as hell isn't a paint can.


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## Lazzer408 (Feb 20, 2010)

Wile E said:


> No they haven't. You're SOL there, tho I bet you could come up with something. . You positive it's not a simple crossover issue?
> 
> And what's this about an SVX? Still have the MX3 and 5's?



I sold the 3 last year and bought a '92 Subaru SVX. I took a liking to it but man is that car a brick. I'd love to stick that H6 drivetrain in an Impreza though... then boost it. 

I still have the 5. Want to buy it?


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## Wile E (Feb 20, 2010)

Lazzer408 said:


> I sold the 3 last year and bought a '92 Subaru SVX. I took a liking to it but man is that car a brick. I'd love to stick that H6 drivetrain in an Impreza though... then boost it.
> 
> I still have the 5. Want to buy it?



A roadster makes a terrible car for someone with 3 kids. lol. I'll pass. What approximate whp you up to in it, and still sporting the AEM EMS?

How do you like the SVX. They always intrigued me, but don't really know much about their drivetrain or potential.


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## Lazzer408 (Feb 20, 2010)

Wile E said:


> A roadster makes a terrible car for someone with 3 kids. lol. I'll pass. What approximate whp you up to in it, and still sporting the AEM EMS?
> 
> How do you like the SVX. They always intrigued me, but don't really know much about their drivetrain or potential.



They are 230hp stock and no race winner but it'll get up and go. The AWD is great in the snow. It's comfortable, quiet, smooth, and turns alot of heads. They are known for transmission problems but that's solved with an aftermarket trans cooler. The engine itself doesn't have any bugs that I know of. Seems like the MAF is a common part to fail because both of them did on the 2 SVXs I had. I fixed one. It just had cold solder joints. The other one I sold before I tried to fix it. All in all that car was ahead of it's time. Projection headlights, climate control, ABS standard, heated mirrors, sequential injection and COP sequential ignition, variable intake manifold, dual 60mm(?) throttle bodies, 108% volumetric efficiency if I remember right, 10:1cr, 3.3L which is the same bore and stroke as the 2.2 Impreza engine. It'll even bolt to the trans.
The most unfortunate thing about the engine is it's open deck and the cylinder walls are not very strong. 10:1cr doesn't help but people have put 6psi on it. Sleeve the block and grab some low cr pistons and h-beams and your good for 1000hp. That's what some guy is doing in a dunebuggy with that engine. 

Check out the crankshaft. lol 7 mains.

EDIT - oh btw... About 300rwhp on the MX5. -shhhhh-


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## Wile E (Feb 20, 2010)

Many of the EJ blocks are open deck as well. That's not really a huge deal most of the time. I bet just rods and pistons would allow a halfway decent amount of HP before truly having to worry about the sleeve failing or walking.

And 7 mains?!? Holy bejesus. lol.


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## Lazzer408 (Feb 20, 2010)

Wile E said:


> Many of the EJ blocks are open deck as well. That's not really a huge deal most of the time. I bet just rods and pistons would allow a halfway decent amount of HP before truly having to worry about the sleeve failing or walking.
> 
> And 7 mains?!? Holy bejesus. lol.



Oh yeh. Toss in some stock turbo rods and pistons and you can throw some boost at it. Probably get 400 out of it with a good tune.
If I can find a nice Impreza roller I want to do a swap. It'll probably be OBD2 but I'll grab whatever 6 cylinder turbo ECU I can find and wire it in. The hardest part is the crank and cam sensors. I'm sure I'll have to re-tooth it to w/e ECU I use.


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## Wile E (Feb 20, 2010)

Lazzer408 said:


> Oh yeh. Toss in some stock turbo rods and pistons and you can throw some boost at it. Probably get 400 out of it with a good tune.
> If I can find a nice Impreza roller I want to do a swap. It'll probably be OBD2 but I'll grab whatever 6 cylinder turbo ECU I can find and wire it in. The hardest part is the crank and cam sensors. I'm sure I'll have to re-tooth it to w/e ECU I use.



The forester had a 6 banger turbo option at one point in time, iirc.

But, even if it is OBDII, you don't absolutely need a turbo 6 ecu. A standard 6 cyl ecu would serve. Use it for all emissions and other mundane tasks, and use a parallel ecu for the real tuning.


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## sneekypeet (Feb 20, 2010)

On topic please.

I know its auto audio related, but lets not get too off line


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## Wile E (Feb 20, 2010)

sneekypeet said:


> On topic please.
> 
> I know its auto audio related, but lets not get too off line



You sadden me Sneeky. 

And ok, fair enough. We did get a bit far off track there. lol.

To bring it back into line: Laz, how do you think this box design would react with some polyfill?


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## department76 (Feb 20, 2010)

polyfill in a vented box?  o plz.

this thread digressed from basic cognitive decision making to commatose.


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## Wile E (Feb 20, 2010)

department76 said:


> polyfill in a vented box?  o plz.
> 
> this thread digressed from basic cognitive decision making to commatose.



That's why I asked how it would effect it. Never tried poly in a vented enclosure. Curious as to what it would do. The conversation can do without your little personal jabs.


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## Lazzer408 (Feb 20, 2010)

The poly worked ok. The inside wall has 1/2" poly around it.

Pollfill is used on the walls of a ported enclosure to dampen the reflected or standing waves inside that can reflect against the backside of the driver or out the port. Polyfill can also be used in acoustic suspension (sealed) enclosures to slow the wave inside the enclosure. The whole box is stuffed to do this. It has the effect of making a smaller enclosure perform as if it were larger then it is. This is why it's often found in small bookshelf speakers.



Wile E said:


> A standard 6 cyl ecu would serve. Use it for all emissions and other mundane tasks, and use a parallel ecu for the real tuning.



I agree. The FIC piggy in the MX3 did a great job of handling boost tuning. Anything below 0psi was handled by the stock ECU. I just figured for a cheap/easy solution that can handle mild boost. You know what I miss about that car the most? The audio!! The 2 Cadence 10s in that car sounded SO good SO smooth and SO low! I miss it.


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