BillFitzmaurice.info

I am building my school a PA system as a senior project. I finished the first of 4 DR250s so I figured I might as well test it out. It is pretty overpowered by those four subs as you can imagine, they are not at full power.

The subs are TH18's, a diy design from diyaudio. I know it's not a bfm product but it suits my needs better. And they sure are some powerful mothers

Sounds pretty good!

https://www.youtube.com/watch?v=AIgY99MDAqI

All that upper noise from a Beta 10A? Wow!

Looking good so far. Not sure if you played with placement at all but stacking closer to the wall should give you more power on the bottom end and kill some cancellations you might have had.

http://billfitzmaurice.info/forum/viewt ... f=10&t=398

kctess5 wrote: I know it's not a bfm product but it suits my needs better. And they sure are some powerful mothers

Let me guess...you wanted a design that uses an 18" subwoofer?

Yeah it was all one Beta 10. I was amazed. I don't think I was driving it over x-max either. I listened carefully for distortion. The compression drivers sound fantastic. I am glad I went for the more expensive option.

I will play around a little with the placement, I just didn't have enough time before.

I was asked to DJ a carnival type event on the 19th of this month. Hopefully another main speaker will be done by then so I can get some stereo action going on.

And as far as the subs go I liked the simplicity of that design, I liked that it was open source, and I am eager to help the DIY crowd out. When this is over I will be providing as much information about them as I can. And I am very happy with them so I am glad I went with that design.

I didn't look at just the driver size, but also measurement, simulations, dimensions, cost, etc. If a 15" design can give me more than a 18" design then I would go with it, but I did not find that to be the case.

kctess5 wrote: I was asked to DJ a carnival type event on the 19th of this month. Hopefully another main speaker will be done by then so I can get some stereo action going on.

Nice demo

With the narrower horizontal dispersion of the CD's, I wouldn't bother running in stereo! Stereo separation dissappears after 13 feet and you have to be standing in the correct place to appreciate it.
I'd put left and right in and run to mono, especially outdoors.
If you build another set of cabs later on, build them with the melded array. Due to their wider dispersion you could run in stereo then, and listeners would have a larger stereo effect area in which to stand...

kctess5 wrote:I didn't look at just the driver size, but also measurement, simulations, dimensions, cost, etc. If a 15" design can give me more than a 18" design then I would go with it, but I did not find that to be the case.

Did you look at all of Bill's 15" driver designs?

Bills cabs with 10's out run a lot off 18's and I know I've had both.
I'd go for a 10 any day far less mass to flap about.

The TH18 isn't a bad design, it's flatter than the T48, but that's obtained at the expense of low frequency extension and excursion control. I don't do tapped horns because of their higher excursion. You can get around that with longer excursion higher powered drivers; Danley does. But as he gets $4k and up for his cabs he can afford to load them with $400 drivers.

I'd go for a 10 any day far less mass to flap about.

I know that someone is always going to have a *better* idea, but I am happy with my choices. And I can guarantee you that these subs beat the hell out of any 10" subwoofer.

I've actually found the compression horns to have pretty good dispersion. And I am willing to trade some off axis response for better sound quality. Once again, I am happy with the choices I made.

lincsoldbird wrote:Bills cabs with 10's out run a lot off 18's and I know I've had both.
I'd go for a 10 any day far less mass to flap about.

Yes, poorly constructed and mediocre 18" subs. As i've said before, Bill's cabs do what's advertised and Bill has posted, I can confirm that, but they definitely aren't miraculous. A bp102 can only do so much.

Well my subs aren't poorly constructed or mediocre. If you believe otherwise I invite you to come hear them yourself. With that same logic, a 1992 Honda Civic could be considered better than a Lamborghini Reventon, if the Lambo's tires were shredded that is...

The B&C 18PS76 is a beast at a good price, and with 16mm useable peak to peak excursion at my max power I don't run into any issues.

It's not that I don't think that BFM makes good designs (I built the DR250...), I just happen to think that they are not the only options. I designed this system with many factors in mind, size, complexity, flatness, etc. Among those factors was the fact that I don't think it makes sense to pay for one design when there are a several open source designs that will do exactly what I need. I know that $15 isn't much compared to the overall price, but does it really matter what that cost is? If something else can suit my needs for free, and I can give back information to the community that has been so supportive in the past?

kctess5 wrote:Well my subs aren't poorly constructed or mediocre. If you believe otherwise I invite you to come hear them yourself.

He wasn't arguing with you, he was agreeing.....

kctess5 wrote:It's not that I don't think that BFM makes good designs (I built the DR250...), I just happen to think that they are not the only options.

You are right of course. I think some folks forget this as you see this kind of "brand loyalty" on every forum on the net. I like bills designs and don't mind paying a small amount to the designer. I still consider building a bfm design to be DIY.
Keep spreading the DIY message.

Did you make another video with the matching DR250?

TimpBizkit wrote:This is probably the best video of a DR250 at WOT I've seen to date! It really shows what the cabs are capable of - enough for a disco in a field by itself!

Thanks!

chrapladm wrote:Did you make another video with the matching DR250?

Not that's worth posting... Not that you mention it I am kicking myself because I am off to MIT for college and won't see the system set up and running again for who knows how long.