Looking to build a small DIY passive subwoofer

[alaskaleftybass]

Hi gang, I have a very small PA with 2 x 10" speakers I like to use for wine tastings, retirement homes, business events, etc. I love it but I need more bottom. So I was thinking--I would like to build a small passive subwoofer. It would only be a 15" cab, built lightweight with 5/8" plywood.

I would like to use a passive filter so I can pass the mid and high along to one of the 10" speakers, or maybe even just run the head mono and dedicate one power amp for the subwoofer.

Any suggestions on where I could find a passive crossover that would forward the signal to the 10" speaker?

Any other thoughts are appreciated.

Thanks in advance!

 

[lelandcrooks]

Mono the system, by far the easiest solution. 10-12mh iron core coil, like an ERSE ESQ on the sub, let the tops run full range. If you want to get really accurate with the sub, Erse has calculators on their site.
For a high pass/lowpass complete by the time you buy the big inductors required you might as well buy a cheap electronic xover.

 

[alaskaleftybass]

Mono the system, by far the easiest solution. 10-12mh iron core coil, like an ERSE ESQ on the sub, let the tops run full range. If you want to get really accurate with the sub, Erse has calculators on their site.
For a high pass/lowpass complete by the time you buy the big inductors required you might as well buy a cheap electronic xover.

Thank you so much for your reply. I really like your products! Actually I wish I could find a Greenboy 12-15" passive Greenboy sub! LOL

 

[dheafey]

Thank you so much for your reply. I really like your products! Actually I wish I could find a Greenboy 12-15" passive Greenboy sub! LOL

I'd also consider a Bill Fitzmaurice Omni12. You can build it as a sub (leave out the mid and hi drivers) or, better yet, build a full range Omni12 for a one cab solution. Bill has several other speaker cab solutions that could fit the bill (Jack12, Simplexx, etc...), but the Omni12 is the one I have the most experience with.

 

[mbelue]

I'd also consider a Bill Fitzmaurice Omni12. You can build it as a sub (leave out the mid and hi drivers) or, better yet, build a full range Omni12 for a one cab solution. Bill has several other speaker cab solutions that could fit the bill (Jack12, Simplexx, etc...), but the Omni12 is the one I have the most experience with.

Why would you build ANY of those for a subwoofer? Bill has about a dozen other designs better suited for subwoofers. Titans and Tubas speaking.

 

[Downunderwonder]

Why would you build ANY of those for a subwoofer? Bill has about a dozen other designs better suited for subwoofers. Titans and Tubas speaking.

OP asked for small. The smallest slim Titan takes up the entire back seat and the smallest Tuba won't fit through the door.

 

[mbelue]

OP asked for small. The smallest slim Titan takes up the entire back seat and the smallest Tuba won't fit through the door.

And the Simplexx subwoofer designs are nearly the same size as the smallest Tuba. Same goes for the Omni.
Bill doesn't have a good small direct radiator plan. I believe he doesn't like them cause they're "inefficient."

Bill is a great designer just not for what the OP wants. He'd be better off with a dozen other designs.

 

[alaskaleftybass]

Thank you guys. I'm listening to all suggestions. Suggest on!

 

[Downunderwonder]

The advantage of horns is lots more bass from a smaller driver and amp, but the boxes get big fast if you lower frequency requirements. What's the biggest box you can deal with?

 

[alaskaleftybass]

The advantage of horns is lots more bass from a smaller driver and amp, but the boxes get big fast if you lower frequency requirements. What's the biggest box you can deal with?

I would say 18 x 18 x 24 inches.... Thanks!

 

[Downunderwonder]

That's a little over fearful 12 size.

BFM has auto tuba for vans about 22x15x20, still less cubic inches than your max, but he doesn't rate it for real work as they use cheaper 10'' subs.

Depending on how powerful your amp is you might get some good use out of one without blowing it up.

 

[lelandcrooks]

Thank you so much for your reply. I really like your products! Actually I wish I could find a Greenboy 12-15" passive Greenboy sub! LOL

At the risk of promoting something I sell, there are 12sub and 15sub plans on greenboy's cab page. Also on Eminence's site Jerry McNutt has posted cabinet designs for almost all of their drivers. You only get the cab size, but it's pretty easy to figure out a box from what he gives you.
With Bill's cabs a Tuba 24 is the one you'd want, 18wide
.

 

[dheafey]

Why would you build ANY of those for a subwoofer? Bill has about a dozen other designs better suited for subwoofers. Titans and Tubas speaking.

Size, that's why you'd build one. Many of Bill's full range designs (Omni's, Jack's, and Simplexx's) have low section only options and are typically smaller than the Titan/Tuba range. As Bill is quoted saying A MILLION times, "It's in the plans."

That being said, Leland (Speaker Hardware) is the authority.

 

[alaskaleftybass]

Thank you guys. I will go take a look.

 

[wcriley]

At the risk of promoting something I sell, there are 12sub and 15sub plans on greenboy's cab page.

I have used 12/6 and 15sub fEARful cabinets as PA subs (band passed at 40 - 100hz) in situations that didn't require massive LF volume.

 

[mbelue]

Size, that's why you'd build one. Many of Bill's full range designs (Omni's, Jack's, and Simplexx's) have low section only options and are typically smaller than the Titan/Tuba range. As Bill is quoted saying A MILLION times, "It's in the plans."

That being said, Leland (Speaker Hardware) is the authority.

Right but look at the sizes. The Omni 12 is bigger than the t24. Same with the Simplexx sub15 it's larger. Neighther one really goes that low or that loud.
A Jack isn't suitable either it's horn loading takes place in the mids. Really dude they aren't suitable.
I've got the plans.

 

[dheafey]

Right but look at the sizes. The Omni 12 is bigger than the t24. Same with the Simplexx sub15 it's larger. Neighther one really goes that low or that loud.
A Jack isn't suitable either it's horn loading takes place in the mids. Really dude they aren't suitable.
I've got the plans.

Then help out the OP. What would you suggest?

 

[mbelue]

Then help out the OP. What would you suggest?

I have used 12/6 and 15sub fEARful cabinets as PA subs (band passed at 40 - 100hz) in situations that didn't require massive LF volume.

With an extended shelf port for more LF extension. No crossover.

Jerry McNutt has posted cabinet designs for almost all of their drivers.

That probably works best with a little math.

 

[alaskaleftybass]

Thank you everyone for your input. I'm looking at all possibilities. Good ideas here.

 

[Steve Dallman]

I have three 350 watt MCM 12" drivers in cabinets. One is in a three way, modified TL cabinet (with 6" mid and tweeter), one is in an 800Hz low passed TL cabinet and the other in a 12" car sub band pass cabinet tuned to the speaker.

These have been superb speakers. I have 500 watt 15's from the same series, but the performance of the 12's is more than enough for me.

We trigger the kick with an Alesis D4 drum module, and run the output to the PA and to an onstage amp into the car sub which we put onstage. It's a hell of a performer, usually crossed around 100Hz. I've used it for a PA sub many times. For bass (I play 5 string) the pair of 12's fill a room easily and with my PF500, I'm not pushing them hard at all. I am thinking of adding a. 30Hz high pass to even trim the very low end some.

I put one 15 version in a sealed cabinet the size of a rack mount PV cabinet (17WX17 deep, 19high) and as small as that cabinet is, it is a monster.