PMA250 used in Personal Line Array

[axes4less]

Just wanted to share a successful DIY project. Hopefully you can see the pic I attached. The array is (8) of the famous Pioneer NSB 4" Full Range drivers in a sealed cabinet to get the best transient response. The ported sub has (2) of the Goldwood 6.5" 8ohm drivers. I built a 2nd order 2-way LR passive crossover at 182Hz, which balances the system nicely. (did testing with an active crossover and separate 2-channel amp first to find the best point)

Will be building one or two more of these. Might end up trying the new Dayton ND90 3.5" full range drivers in the array.

Question: I wasn't sure how to compensate for the space that the plate amp and crossover take up in the sub cabinet. Can anyone advise on how to calculate for this....or better yet, just tell me how much cu ft you'd allow for the PMA250? Not sure it matters uch, but if the experts on this forum think it does, my next project will compensate for that.

[Paul O]

Re: PMA250 used in Personal Line Array

Nice job there.. I'm not sure I would have picked the same color to finish it but that's what makes this an individual hobby. If this amp module had a rear cover it would consume more volume but as it is it's probably not very significant. If you want to get an idea just calculate the volume of several cubes roughly the same size as the transformer and PCB assemblies, that will be close enough.

P.S. What drivers are in the bass module?

[axes4less]

Re: PMA250 used in Personal Line Array

Drivers in the sub are Goldwood GW-206/8 6-1/2" OEM Woofer 8 Ohm

My daughter ended up using this system....which is why the purple color. However, I probably will never paint another system "black" again.....I'm actually liking more brilliant colors for my DIY projects. Also have one flourescent green :D

[Randy L]

Re: PMA250 used in Personal Line Array

Why not just remove the plate amp and measure its dimensions? Anything that takes up space in a speaker enclosure will affect the bass reproduction.

[Taterworks]

Re: PMA250 used in Personal Line Array

Let me start off by saying I'm not a fan of the color. Sorry. Just doesn't do it for me. And I'm really not sure what's going on with that little sub, which wouldn't even be enough for my living room, but I really think you're onto something with the general concept.

I think systems similar to this one are the future of small-venue live sound. The 15" two-way box has had its day for the most part. The line array loudspeaker format has obvious advantages in pro audio applications (though I haven't been a fan of them for hi-fi use) chief among them being the -3dB vs -6dB/doubling of distance decay characteristics, but also the greatly reduced sight lines. Renkus-Heinz' IC-Live array is goofy-looking and cumbersome with a complex setup process, and requires using the sub to get the necessary elevation, but I really think we're going to begin seeing more small columnar line arrays that are pole-mountable, and I don't know why we haven't already. You can take eight of the Goldwood 4" woofers and get an array that you can dump 250 watts into and get some real volume out of, and we've got drivers that are good in multiples for line-source HF duty like the Dayton PT2, and you don't even have to worry about horn coloration. The only downside I see is complex construction, a large number of drivers, and reduced horizontal pattern control and off-axis rejection in the lower midrange and midbass (which you exchange for lots of vertical pattern control).

Column speakers are all the rage right now, if you pay any attention at all to the pro audio and installed sound markets. JBL's got them now, EAW has them, Renkus-Heinz has their steerable Iconyx one, Community has one now, and Bose was the first that I know of to the table with a modernized line source, though just about everyone used them back in the day...EV/University, Bogen (for crying out loud)...what's old is new again in a big way, and more manufacturers are going to hop on the bandwagon.

[Paul O]

Re: PMA250 used in Personal Line Array

I think systems similar to this one are the future of small-venue live sound. The line array loudspeaker format has obvious advantages in pro audio applications (though I haven't been a fan of them for hi-fi use) chief among them being the -3dB vs -6dB/doubling of distance decay characteristics, but also the greatly reduced sight lines. The only downside I see is complex construction, a large number of drivers, and reduced horizontal pattern control and off-axis rejection in the lower midrange and midbass (which you exchange for lots of vertical pattern control).

I have been wanting to build something like this myself for some time now but money is tight so I have been putting it off. There is 1 commercial offering that is nearly exactly what you describe.. http://www.slsloudspeakers.com/content/view/264/107/
It's expensve of course so it's not in the same market as your typical 15+1 box and that's just as well because a system like this isn't the right tool for all applications. I think if these were widely available we'd be hearing as many bad reviews about them as anything, because just like the large format arrays there seem to be as many people that don't understand how to deploy it properly as there are that do, but everybody has got to have one anyway because it's the new thing and all the artists demand it.