midrange tweeter cab - anyone else

[Montanamike]

After being frustrated for years with the tinny, undefined highs of the standard piezo tweeter in most bass cabs, I decided to build my own. 4-5 1/4 and 2-1" tweets. Less than $150 dollars invested. It makes a huge difference in clarity and beauty of the sound. The transport cover (with the cross) is sitting on top.

[kesslari]

Looks great! where do you have it crossed over, and do you low-pass your bottom cab?

[Montanamike]

Originally Posted by kesslari

Looks great! where do you have it crossed over, and do you low-pass your bottom cab?

I am running a GK 800RB which has a variable crossover in it. It sounds best set at about 500 Hz, the tweets ate crossed at 3.5K. I picked these 5 1/4's based on a great freq curve from 300-4.5K and power handling, of-coarse.

[Crockettnj]

They look very professional!

What 5 1/4" mids did you use in that?

Any thoughts on the splayed arrangement vs crossfire? Not sure if the difference would matter for bass guitar use.

[Crockettnj]

Mike, do you have a larger pic of the bass in your avatar? Looks like a trans green j bass with great grain?

[Montanamike]

Originally Posted by Crockettnj

What 5 1/4" mids did you use in that?

Any thoughts on the splayed arrangement vs crossfire? Not sure if the difference would matter for bass guitar use.

I used peerless 8ohm run in series / parallel combo to keep it an ohm cab, i got them from parts express, I can dig up the part number if you want.

I went with splayed based on 2 factors:
1. the cab is easier to build
2. 15 degrees fit the axis parameters of the driver well, and cross fire might have some cancellation though I have no physics to support this assumption

[Montanamike]

Originally Posted by Crockettnj

Mike, do you have a larger pic of the bass in your avatar? Looks like a trans green j bass with great grain?

Thanks, I built this bass a few years ago. The wood is great, it is single piece of swamp ash except for the very top of the upper wing. It has been finished a few times and the trans-green was a bit of luck. The clear is hand rubbed lacquer.

[Crockettnj]

Wow. Great looking bass.

[billfitzmaurice]

Originally Posted by Montanamike

I went with splayed based on 2 factors:
1. the cab is easier to build
2. 15 degrees fit the axis parameters of the driver well, and cross fire might have some cancellation though I have no physics to support this assumption

Cross-firing actually has far fewer phase, response and dispersion issues than splaying. That's why you see the mid-drivers on so many high end PAs crossfired, like this one:

[Montanamike]

well there ya go

[Montanamike]

Bill,

I use my cabs for small shows and practice, not as a PA so the issues you listed don't seem to be a factor. I just wish I would have called you first. I'm just a lowly Civil Engineer so if you need a sewer line fixed give me a call, I'll leave the speaker design up to you. I still thinks it's pretty good for a rookie.

BTW: It sounds Great!!!!

[billfitzmaurice]

Originally Posted by Montanamike

Bill,

I use my cabs for small shows and practice, not as a PA so the issues you listed don't seem to be a factor.

I cited the JBL example because the level of engineering used by them, and many others, in PA cabs doesn't exist in the electric bass genre. Not that it shouldn't, just that it doesn't. As for your rig, it's definitely an improvement over commercial offerings. But it could be made even better, something to keep in mind when you've got the urge to fiddle around some more. If you placed the two tweeters vertically, with a pair of vertically aligned mids to either side cross-firing you'd notice a substantial improvement.

[Montanamike]

Thanks Bill, Cab size is a big consideration at this point, I think I get the vertical piece, so the tweets dont cancel on the same plane. As for the mids I don't quite understand, but I'll take your word for it. I don't think it would matter that much since there are no fundimentals from the bass in those frequencies anyway. The other design would take more cab height to accomplish and a larger cabinet is something I'm trying to avoid.

The sewer line offer stands!

[billfitzmaurice]

Originally Posted by Montanamike

The other design would take more cab height to accomplish and a larger cabinet is something I'm trying to avoid.

Chances are you could get it into an even smaller net size, though maybe an inch or so taller.

[will33]

Bill's one of the brightest bulbs around here, much to be learned from that guy. What he's advising on is dispersion of the sound, off axis response. Lining speakers up vertically improves dispersion horizontally while reducing it vertically. In our line of work horizontal always wins. If playing to the room, and audience could be 30, 50, or who knows how many feet wide but the difference in ear level of a tall person standing and a short person sitting might be what, 4 ft. In playing stage volume only, PA doing the work out front, it's still better to spread your sound wide across the stage so all your bandmembers can hear each other better and stay together/play tight. The difference in ear level of the drummer sitting down and the tallest guy in the band might be 3ft.

That's why 410, square bass cabs and 412, square guitar cabs, although being popular and selling like hotcakes are some of the worst designs there are. People centered on the cab are getting their heads taken off and the folks off to the sides can't enjoy anything that sounds good.

[Montanamike]

This all makes great sense to me. I love learning new stuff. BTW I'm not one of the brightest around here I just love to tinker. Do you have any designs for bass cabs that you would recommend? What angle do you put the drivers at fot the best dispersion?

I saw an old GK design 4-12 that had the woofers facing in a V. It is on the tour video that Norm Stockton did in the Blog area of his website. You got me thinking now. I really appreciate the advice guys.

[will33]

I'm not one of the brightest either, I learned most of this stuff from reading here, some other places, curiosity and learn something new almost everyday. I don't know what GK you're talking about but it sounds like crossfiring. Imagine a laserbeam coming straight out from the center of the speaker...did it have 2 speakers mounted on the left side of the cab pointing across the front the right side of the cab and the other 2 speakers vice versa, mounted on the right pointing across the front to the left?

[Montanamike]

It was the original prototype, called a GMT. He shows it at about the 4:00 mark of the video.

BTW I'm a huge fan of Norms!

Here's the link:
http://normstockton.blogspot.com/201...ur-part-1.html

[will33]

This one? http://www.normstockton.blogspot.com/

You have to scroll down toward the bottom of the page, it's the 3rd video from the bottom entitled "The GrooveSpot: Episode 8 - GK factory tour"

Cool video. Both norm stockton and bob gallien seem like really cool guys. I would love to have 1/2 of that guys playhouse...er...I mean facility...or maybe I'd call it a war house.

And yeah, that's a crossfired 412, from a technical standpoint, one of the best designs of all those cabs.

[will33]

Oh, I see you posted a link there. Maybe I didn't see it before but it's the same video.