Voxel - a mini-sub+

[Paul Carmody]

I brought this project to InDIYana 2013, but never put any info out there about it. A thread a few days ago asking for a small sub prompted me to get myself in gear and post the plans.

I designed the sub around this amp, although obviously any sub plate amp will work (depending on how creative you want to get mounting it to the somewhat small enclosure). Is this amp truly 68 Watts? Probably not, however it has the neat bonus of allowing you to add bookshelf speakers to create a 2.1 setup.

The only other things you need to do this project are:

• TB W5-1138SMF (great little workhorse)
• 2 of these vents, glued end-to-end
• 1/2" plywood or MDF.

The approximate volume of the enclosure is around 7 Liters, and it should reach an F3 of 35 Hz. I don't have an exact number for the max SPL, but in theory it should be able to get to 98 dB before the amp runs out of steam. The port diameter may be the weakest link here, and would probably chuff pretty bad if pushed any harder. That driver, it just goes and goes; this is the kind of thing it was meant to do.

[johnnyrichards]

Re: Voxel - a mini-sub+

This is a good execution Paul, and a legitimate contender in the dinky sub arena.

[dustinbagby]

Re: Voxel - a mini-sub+

I was hoping youd write something up, there were a few good ideas thrown around, this one is definitely up there. Need to look into Wolfs build and evaluate my needs. Thanks!

[Wolf]

Re: Voxel - a mini-sub+

Is your Lepai amp drilled for a bolt on the left end of the chassis? I have one, and that is right between the output chips. The bolt is absent in my unit, does yours have one? The chips are greased and isolated, but I was curious if yours had them more securely mounted with a bolt or machine screw?

Thanks,
Wolf

[Brian Steele]

Re: Voxel - a mini-sub+

Wow - a 7 l sub that gets to 35 Hz??

Hmm.... maybe a shelf vent could be used instead of the two vents? A "butterfly" type self vent may address some of the potential chuffing issues.

[Paul Carmody]

Re: Voxel - a mini-sub+

Wow - a 7 l sub that gets to 35 Hz??

Hmm.... maybe a shelf vent could be used instead of the two vents? A "butterfly" type self vent may address some of the potential chuffing issues.

I'm willing to consider it, but what's a butterfly shelf vent?

[Brian Steele]

Re: Voxel - a mini-sub+

I'm willing to consider it, but what's a butterfly shelf vent?

Oh good grief - I meant "bowtie" vent. Think of a shelf vent where the cross-section contracts and then expands, giving it a cross-section looking like an elongated bowtie. Tom Danley uses it in one of his pro audio sub designs. Supposedly does better dealing with chuffing and should give a lower Fb than a normal shelf vent of the same length. It can be modelled in HornResp.

[Jeff B.]

Re: Voxel - a mini-sub+

Wow - a 7 l sub that gets to 35 Hz??

Hmm.... maybe a shelf vent could be used instead of the two vents? A "butterfly" type self vent may address some of the potential chuffing issues.

The last thing I listened to at InDIYana this past April was this sub. Everyone was running around grabbing their gear and packing up, and there was Paul sitting up front on thr floor with this "shoebox", and it was cranking out all of this bass. I said, "that's just crazy!", and we both laughed at it. You really don't expect a little box that small to be putting out that kind of bass. It's a very cool little sub.

[[email protected]]

Re: Voxel - a mini-sub+

Paul, could you post the simmed FR for this? I simmed its big brother and it has a huge peak. Curious what you did.

[kevin007]

Re: Voxel - a mini-sub+

Paul,

Since the TB sub is on back order to next year, could this sub be used instead? http://www.parts-express.com/pe/show...number=264-831

It is the Neodymium version of the sub you used for the voxel.

Kevin

[nrg74]

Re: Voxel - a mini-sub+

A sub from a 5 1/4 driver, hard to believe! I may have to build two... why wait for a writeup? I think I have enough info to build it... imagine taking this to an outdoors event and driving it with a car battery, with some other speakers: OS.
Great job Paul.

[nrg74]

Re: Voxel - a mini-sub+

The last thing I listened to at InDIYana this past April was this sub. Everyone was running around grabbing their gear and packing up, and there was Paul sitting up front on thr floor with this "shoebox", and it was cranking out all of this bass. I said, "that's just crazy!", and we both laughed at it. You really don't expect a little box that small to be putting out that kind of bass. It's a very cool little sub.

Great story! Nice galvanizing moment.

[tomzarbo]

Re: Voxel - a mini-sub+

Is the Ferrite version of this driver less noisy than the neo version? I have three of these in the neo format, and they are all super-noisy. So much so that I had to scrap the plans I had for them. Bought them several years ago.
Just wondering if anyone has tested these free-air to check for noisiness.

TomZ

[Paul Carmody]

Re: Voxel - a mini-sub+

Noisy how?

I do have both versions of the W5-1138, by the way. Yes, the design can be adapted for it, but the tuning would most likely need to be adjusted.

[craigk]

Re: Voxel - a mini-sub+

I have 3 different subs using these woofers ( neo ) and have never had any noise issues with any of them.