$325 Lab 12 based PA tapped horn ~ 35Hz extension

Sounds like fun! I wouldn't be surprised if you get equal output, as the internal walls would make for some pretty good bracing of the sides. Keep us posted!

I've got some flooring to put in for the wife, so it doesn't look like I'm getting my PAL12 started in a hurry. I'd do 2 now if I had the space!

Using BB ply so that should also help.


I will try to post periodic updates, i generally get an hour or two here and there ao it might take a month to build.
 
Just in case anyone's interested, here's a comparison between the sim'd output of the PAL12, and the output of a offset TL based on the same LAB12 driver.

The offset TL is less than half the size of the PAL12.
 

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excursion will limit the OSTL's advantages below 30hz... but that's a moot for PA.



Very flat & smooth though! where's the design for this? would be tempting to use less wood per box, and just more drivers, though you'd need more Amps/watts.

I still like the sensitivity for the PAL12.
 
actually - the smoothness (and size) of the OSTL makes it VERY attractive to me as a studio sub! It looks to still add 2-3db of efficiency to the LAB12!



I'm actually running rare TL studio monitors (capable of 113db), so to leave the 70hz+ out of them and cross over smoothly to a LAB (with potentially 25hz in room + eq)...
 
I have an enclosure very similar to the PAL12 with a Lab12 in my HT. It is much taller though for 20Hz extension. I am very happy with the way it sounds.

I have the wood & drivers for PAL12s and others that have built them are generally very happy with them...so I will move forward with my PAL12 project.
 
My point for posting the OSTL option is that, going with the PAL12 TH instead, you only gain about 2dB in the passband for a box that's over double the volume, AND you end up with a higher cutoff point as well. And bear in mind that I've actually given up a bit of passband gain in the OSTL design to widen the bandwidth.

I don't think the LAB12 is a really good match for a TH designed for 40 Hz pro audio use. Yes, you can get "good" results, but I think you can end up with better results using a driver that's a better match for that type of use.
 
I assume the Fs in the 20s has something to do with your comment about the LAB 12 in a TH for PA use. I'm looking at home use down to 27 hz (lowest note on a piano) and can get drivers needing a reconing free, plus I'm not interested in dealing with the limited bandwidth of the TH. Yet, anyway.
 
Not just a TH, but a 40 Hz TH. The LAB12 was designed for use in a FLH with a small chamber (which results in an Fb > Fs). There's no such "chamber" in the PAL12. The result is a particularly non-flat response, if you build the box as simmed.

I've attached a sim of a simple TH of around the same volume, using a 15" driver that's a better "fit" for a 40 Hz TH. This is the Dayton Audio PN395-8. This can be built using a THAM or MTH type fold (and using the workbooks from my site to come up with the appropriate dimensions for the box). The passband is a lot smoother and the midband gain is better.
 

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Not just a TH, but a 40 Hz TH. The LAB12 was designed for use in a FLH with a small chamber (which results in an Fb > Fs). There's no such "chamber" in the PAL12. The result is a particularly non-flat response, if you build the box as simmed.


Interesting, I recall looking at the original dual LAB sub FLH. I do already have the LAB12 now, so I wanted to build something worthwhile to crank the volume, use a bit for PA (I'd build 2), and maybe even turn on in the van for fun.
Is there another design you'd recommend for the LAB12?


I've attached a sim of a simple TH of around the same volume, using a 15" driver that's a better "fit" for a 40 Hz TH. This is the Dayton Audio PN395-8. This can be built using a THAM or MTH type fold (and using the workbooks from my site to come up with the appropriate dimensions for the box). The passband is a lot smoother and the midband gain is better.


I'd consider building 15" compact TH, smooth & loud sounds great! A couple of those would probably kick butt for the main bands I'm running, as well as more electronic music if I decide to perform with them.
 
Assembly pics

Here are some photos from my PAL12 building process. About 5 hours in so far.
 

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