Finally taking the plunge (Dayton PA310-8 TH)

[Brian Steele]

Well, I'm finally taking the plunge - gonna build me a TH based on the new Dayton 12" PA driver - the PA310-8. Specs will be similar to the ones indicated below (I'm still doing some fine-tuning). I haven't finished the folding yet, but I'm looking to fit everything into a box that's approximately 3'x2'x1' (ok, slightly wider, as the driver has to be accomodated). It's destined to be used in a small bar (the rest of the spectrum will be provided by EV ZXA1s installed in various locations). I'll probably end up using four of them, or more, depending on how much output I get from this initial build. As DJs tend to be silly with the volume knob here, I'm trying to split the load across multiple cheap subs rather than one or two more expensive ones .

[Patrick Bateman]

Originally Posted by Brian Steele

Well, I'm finally taking the plunge - gonna build me a TH based on the new Dayton 12" PA driver - the PA310-8. Specs will be similar to the ones indicated below (I'm still doing some fine-tuning). I haven't finished the folding yet, but I'm looking to fit everything into a box that's approximately 3'x2'x1' (ok, slightly wider, as the driver has to be accomodated). It's destined to be used in a small bar (the rest of the spectrum will be provided by EV ZXA1s installed in various locations). I'll probably end up using four of them, or more, depending on how much output I get from this initial build. As DJs tend to be silly with the volume knob here, I'm trying to split the load across multiple cheap subs rather than one or two more expensive ones .

Clone the TH-Mini...

I've built a LOT of subwoofers, and I'd probably have to say that I've never been happier with a subwoofer than I am with my TH-Mini clone.

The usual caveats apply - for serious prosound use, the 'real' TH-Mini has more output than what I am using, and the drivers that Danley uses are known to be more durable. Seems to be a great little sub.

Also, if you're going to purchase four drivers, why not do push-pull? I've used that on the last two I built, and the difference is NOT subtle. I actually ripped apart my "Triple8" sub from diymobileaudio and flipped one of the woofers, and that made a big difference.

Last but not least, aren't you in another country? Faital Pro is more expensive than Dayton, but the shipping will cost less. Not sure what distributor you'd use, but this gives you an idea of the pricing:

http://cgi.ebay.com/FAITAL-PRO-W12N8...#ht_2392wt_801

[Brian Steele]

Originally Posted by Patrick Bateman

[font=verdana] Clone the TH-Mini...

This design is probably going to a look a bit like the TH-Mini, maybe slightly thinner .

Originally Posted by Patrick Bateman

[font=verdana]Also, if you're going to purchase four drivers, why not do push-pull?

Box size. Smaller single-driver multiple boxes rather than bigger boxes with multiple drivers will serve this particular requirement (bass for a small bar) better.

Originally Posted by Patrick Bateman

[font=verdana]Last but not least, aren't you in another country? Faital Pro is more expensive than Dayton, but the shipping will cost less.

Yup, shipping is a b*tch. I'm not sure that I will save much by going with the Faital Pro - shipping will still be high.

[Patrick Bateman]

Originally Posted by Brian Steele

This design is probably going to a look a bit like the TH-Mini, maybe slightly thinner .



Box size. Smaller single-driver multiple boxes rather than bigger boxes with multiple drivers will serve this particular requirement (bass for a small bar) better.




Yup, shipping is a b*tch. I'm not sure that I will save much by going with the Faital Pro - shipping will still be high.

I'd read that Faital is manufactured in Mexico, and their website indicates that they have a factory in Puebla, so it seems like they'd offer a good value to folks in South America. But I just checked the box on the woofers that I purchased from them this week, and it says "Made in Italy." Hmmm.

[Brian Steele]

Originally Posted by Patrick Bateman

I'd read that Faital is manufactured in Mexico, and their website indicates that they have a factory in Puebla, so it seems like they'd offer a good value to folks in South America.

It would probably be just as expensive to ship it to me, LOL.

I might have more luck with Selenium stuff (I believe Brazil is the source for that). In fact, one of my friends built an entire PA rig (tops, midbass and horns) using Selenium components and plans they provided a few years ago and used it to provide the sounds for my brother's Carnival band. It was easily the clearest, cleanest and loudest rig on the road. OTOH, most of the competition basically seemed to be of the "what else can we fit on the truck" type.

Maybe I should give their bass drivers another look...

[Brian Steele]

Can someone help me fold this into a TH? I might end up using the simple folding scheme in my POC #1, but just looking for other ideas...

[Brian Steele]

Published specs:

Vas: 2.89 cu.ft.
Fs: 44.4 Hz
Qes: 0.34
Qms: 8.63
Qts: 0.32
Le: 1.5 mH
Re: 5.7 Ohms

Measured specs:

Vas: 3.30 cu.ft. (need to confirm)
Fs: 39.0 Hz
Qes: 0.31
Qms: 7.50
Qts: 0.30
Le: 0.37 mH (!!)
Re: 5.2 Ohms


The low Le came as a big surprise. It's significantly different to the published spec. So much so that I measured the parameters of another driver with the WT3 just to ensure that it was still working (and measuring Le) properly (I got the expected Le for the test driver during those measurements). 0.37 it is.

Published Xmax for the PA310-8 is 5mm, but some quick tests suggest that might be a bit on the generous side - the suspension seems to be applying the brakes quite a bit before 10mm p-p is reached and distortion quickly rises. On the plus side, I was unable to get it to bottom while driving it free air with low frequency test tones.

I'm rethinking my TH idea. Maybe I should just go with a simple EBS alignment...

Nah.

[djk]

The coil is much shorter (and less x-max) with a low value of Le.

[Brian Steele]

Originally Posted by djk

The coil is much shorter (and less x-max) with a low value of Le.

LOL - perhaps Xmax is really 0.5mm instead of 5.0 mm?

Seriously I took a look at the coil (shone a flashlight through the spider), and it looks like there's what could be about 5mm sitting above the gap. Also, when I pushed the cone outwards, there was still a bit of coil in the gap at the point where the suspension brought the cone to a halt.

More about the PA310-8 can be seen here: Dayton PA310-8 12" Pro Woofer | Parts-Express.com

The specs claim a "Low distortion motor system w/copper cap." Perhaps that has something to do with the low measured Le.

[djk]

Didn't see the part about the copper cap, that would lower Le too.