My (in progress) project *pics too*

[captainobvious99]

Since seeing Dan's 'blades' I had been itching to build a pair of speakers with the same (or very similar look at least), but with different 'guts'. I just love the lines and the hard edged look of them (well done Dan!) I've had my drivers ordered and sitting in the basement for months and it's about time I finally got this project going.

This (when completed) will be my first home speaker build. A bit ambitious? Yeah, you could say that. Even I'm a little intimidated...
I've tinkered around in the car audio realm, but I have very little wood working skill. For me, jumping right into the fire has always been the best way to learn. It's very impressive seeing some of the high quality work that you DIY'ers are pumping out. Both technically, and in terms of craftsmanship. There's alot for me to learn here from you fellas

Anyway...on to the specifics...

The build is an MTMWW configuration utilizing the following drivers:

Vifa XT25TG30
Tang Band W4-1320SJ
Usher 8955A

I chose the xt25 for its good smooth extended frequency response. The W4's I have used before (both W3 and W4 version) and I'm a big fan of the way these bamboo/paper cones produce vocals. The 8955A's were chosen for their low distortion and ability to play low. I could have gone cheaper, using the 10" Dayton drivers (I actually have 2 sitting here as well to play with), but I've been wanting to try the Ushers for a while so I figured what the heck.

These speakers will be actively crossed over using a Behringer DCX2496 and powered by 6 seperate channels via gainclone amplifiers that I am in the process of building. I decided to go this route because I love the flexibility of the active crossover and the ability to tweak on the fly without having to stock a ton of crossover parts. That, and I'll probably be building more projects down the road so shared use is a plus.
The Base cabinets will house a pair of 8955a's each with a shared airspace and will be vented. The Mids will share airspace and will be sealed.

I plan on adding bracing to the base cabinets, fear not!


I started measuring and cutting panels about 2 weeks ago and have been continuing on slowly since then. Im focusing on getting the base cabinets glued up and then I'm moving on to the top. The angle cuts are very challenging with my tools and experience but Im getting there (after some screwups) by being patient and trying some different cutting methods.
The end result, Im hoping will look like this:





Progress pics:









The top panels are simply sitting on top to give an idea of look/shape.

[maynardg]

Nice. Keep 'em coming.

[theLinks]

Very nice, this will get alot of attention.

[pypes]

Nice progress so far. You and I are kind of in the same boat.. 12v guys jumping headfirst into extensive home projects. It'll be some headaches along the way but you'll figure it out by, like you said, being patient and thinking through the situations that come up. I'm finally getting close to being done.

Love the look you're going for. Dan's blades really do have a successful outside-the-box styling. I'll be staying tuned to your build!

[MrkCrwly]

Very nice design. This is going to be fun to watch.

[spasticteapot]

I like the design. What's the internal volume?

[captainobvious99]

Thanks fellas.

I like the design. What's the internal volume?

Internal volume of the base cabinet is appx 3 cubic feet.

[Wolf]

It looks like you have the MTM spread pretty far in your top cab. The closer they are, say 1/4" spacing between, the better your lobing and integration can be.

Later,
Wolf

[captainobvious99]

It looks like you have the MTM spread pretty far in your top cab. The closer they are, say 1/4" spacing between, the better your lobing and integration can be.

Later,
Wolf

Good point Wolf. The sketchup picture doesnt show it well (because the flange on the W4's is colored grey..doh), but my measurements even in the sketchup actually are 1/4" spacing between the mounting flanges of the mids and tweeter. Also the same way I punched it into PCD.

Nice catch though. I should re-color those flanges so they dont look so off...

[captainobvious99]

Dusting off the PCD sim I did on these a while back. I'm going to have to go over these again to recheck all distances and measurements.

[bmaupin]

Why is the system impedance so low?

[johnnyrichards]

Just a suggestion on the sims - fix your FRD files. I doubt the woofers have that nice, ultra flat high end response, for example. You can add an approximation of the natural roll-off using Bagby's "Response Modeler".

Also as noted, your impedance will make most amps sweat a bit.

[Wolf]

If you guys will notice- he's going active, and the impedance is actually of little concern. I've already stated this at some point prior wrt this build, and ended up being informed of this fact at that time.

As to more realistic plots, that is a reasonable suggestion.
Later,
Wolf

[captainobvious99]

I believe the woofers look like that because I only traced them to a certain point. I guess I figured I didnt need the response numbers calculated in at that high of a frequency if it was going to be crossed over well below that range. Incorrect ?

And yes, Wolf is right on re: active crossovers.


How are you guys getting your FR plots? Are you measuring yourself or just using the manufacturers graphs? (Which is what I did)
I no longer have the ECM mic but I know my friend has one...is there a recommended method for measuring FR yourself and would you recommend doing it at this point or just rolling with the OEM graphs and then doing measurements/crossover/EQ adjustments once mounted?

Thanks

[Face]

Also as noted, your impedance will make most amps sweat a bit.

1-2ohm load...a bit? It would cause most a global meltdown.

I agree it's probably his traces.

[captainobvious99]

1-2ohm load...a bit? It would cause most a global meltdown.

I agree it's probably his traces.

Hmm, the traces dont show an impedance that low in the ranges used so Im not exactly sure why it would come out like that. Does PCD ignore the summed impedance curve when using active filters?
Either way, it shouldnt be a big issue. I have seperate amplification channels for L/M/H for each channel and active crossovers. The amps are being built with 4 ohm impedances in consideration. Any concerns you notice ?

[captainobvious99]

Just a suggestion on the sims - fix your FRD files. I doubt the woofers have that nice, ultra flat high end response, for example. You can add an approximation of the natural roll-off using Bagby's "Response Modeler".

Also as noted, your impedance will make most amps sweat a bit.

Will this effect the accuracy of the simulation if the response trace stops at 2K and the woofers LPF cutoff frequecy is 250hz LR4?
Thanks for the feedback Johnny, appreciated

[johnnyrichards]

Will this effect the accuracy of the simulation if the response trace stops at 2K and the woofers LPF cutoff frequecy is 250hz LR4?
Thanks for the feedback Johnny, appreciated

Maybe - it will affect phase for sure. However, as I noted above I have no idea about phase within an active system.

[captainobvious99]

I have a newfound respect for how quickly some of you complete your builds...


Progress is slow, but it's moving along. Cut a few more pieces and glued together the pieces for the top wedge front baffles. Still have to do the bass bin baffles, rear wedge, bracing, bondo any gaps and then sand smooth.

The pieces you see inside the bass bin are the sides for the rear wedge.

[pypes]

Nice progress! All the angles would be giving me a headache.