Build Thread : AE Td10M+Beyma TPL-200h

[DrDyna]

Thanks chrapladm, I'm trying to take my time with this one.

Here's how we're going to route square holes and recesses. This is a Trend Varijig, it's clamped tight to the driver for the size, and once it's removed it can be chased by a top-bearing 3/4" straight cut bit, which should match the radius of the tweeter frame.

 

[chrapladm]

So I am guessing the jig is pretty thick then?

Seeing your guide bearing bit I was thinking you would have to go pretty deep with the router depth if it wasnt. I dread having to route my PHL 10 mid with its octagon shape frame. BUT this should be fun to watch seeing yours take shape.

PLUS I am really curious how quiet this will be on the tweeter side regarding miniDSP noise.

 

[DrDyna]

It's half an inch thick, but I'd planned to cut some 2" x 10" pieces to go between it and the cabinet before I clamp it in place.

The MiniDSP plates are surprisingly quiet, I fired them up running my Fusions with the crossovers bypassed, and running the 108db dna-360 compression driver with only a 33uf cap to protect it, it's essentially inaudible at the listening position, but if you start walking up to it, you can hear it a bit. At 4 feet away it's about on par with the noise my fan modded ep-2000 makes.

The 200/h is around 4 db less sensitive. I may also pad the tweeter with actual resistors.

 

[chrapladm]

Ah, well thats good to hear then. I looked at possibly using one of their 2 channel amps for my build or possibly a Hypex with slightly more power.

Do you have the veneer already or did you have the thought of veneering it in the possible plans?

 

[DrDyna]

Kinda been going back and forth on the veneer, I might do a quartersawn of some type, maybe walnut, and stain it a little darker.

 

[DrDyna]

Last wait for glue setup before the acoust-x goes in. Man, the excess glue looks terrible in a picture! lol. It all gets scraped up anyway, and covered with the acoust-x.

 

[Sonnie]

Looking good.

 

[chrapladm]

I am curious how the acoust-x does. I thought about buying that product to line my walls for my outdoor shed build. BUT the budget is already starting to get out of hand.

 

[DrDyna]

Not too shabby, I guess. I guess Beyma's radius is just a blonde one bigger than 3/4".

 

[DrDyna]

Still have some flush trimming and sanding to finish up, but here's a size perspective, sitting next to a Fusion 15. You can kinda see the acoust-x grey in there, it's an interesting product. It's toothpaste consistency, the slightest smudge of it on mdf turns the wood dark, almost like oil. A thin coat goes on thick and solid grey, but after a few minutes, the mdf almost completely drinks it up. It took 3 coats before it stayed grey and stopped soaking in. Took almost half the bucket to build it up. Still undecided on if I'm going to paint them or veneer. I'm leaning towards paint, I think I want it to look as it does in the sketchup model.

 

[Todd Anderson]

or fingers

 

[Todd Anderson]

Still have some flush trimming and sanding to finish up, but here's a size perspective, sitting next to a Fusion 15. You can kinda see the acoust-x grey in there, it's an interesting product. It's toothpaste consistency, the slightest smudge of it on mdf turns the wood dark, almost like oil. A thin coat goes on thick and solid grey, but after a few minutes, the mdf almost completely drinks it up. It took 3 coats before it stayed grey and stopped soaking in. Took almost half the bucket to build it up. Still undecided on if I'm going to paint them or veneer. I'm leaning towards paint, I think I want it to look as it does in the sketchup model.

View attachment 4365

Looking super nice!!

 

[DrDyna]

Getting closer!

 

[Sonnie]

Nice... is that Duratex?

 

[DrDyna]

Not duratex this time, just paint. The chip says "Tricorn Black", it's a Sherwin Williams.

 

[Sonnie]

Okay... so the texture is the acoust-x grey?

 

[DrDyna]

Okay... so the texture is the acoust-x grey?

I think the lighting makes it look a bit more textured than it is, but it's just rolled on paint. It orange peels a little bit, I haven't decided if I'm going to cover it with a clear or not yet, I kinda like the flat. The acoust-x you can sorta see the color of on the inside, but it's a very light grey compared to the outside. I did 4 medium coats inside, it's probably built up about 1/32".

 

[DrDyna]

Here's a closer look what the acoust-x looks like inside.

 

[DrDyna]

Ended up going with circular vents, easier than slots.

I may still recess the plates, I thought I would dig the surface mount, but I'm not sure. Gonna see if it grows on me.

 

[Sonnie]

Looking at the driver on that speaker on the right, it may just be some graininess in the picture that is making it look textured.

 

[DrDyna]

Yeah, I think it's time for a new camera, which means new phone..

Ah well, everything is in! I'll probably be farting with the crossover for a couple of days, but I'm pretty pumped for a listen. I'm going to give FIR filtering a try with these, since I don't have to worry about A/V sync, as it's just a 2 channel system for now, with no video sources.

 

[Sonnie]

They look sweet... would love to hear them. Can you run them down (over/up) here for the weekend?

 

[DrDyna]

Hah, well, if you were next door, maybe! A few minutes ago I carried a completed one for a minute, really don't want to have to do that too many times It's probably going to take a few days before they're listenable, depending on how this first go at FIR and time alignment with different processing speeds depending on filter taps. We shall see!

Here's a pic of the leads I made that go from the plate amp to the terminal cabinet-side in the plate amp's cubby. Loves me some Neutrik connectors, and I had to install the "I drink sometimes and I still remember the ip address of the DSP" capacitors, plus the plate amps have a bit of turn on / off scratchy.

 

[DrDyna]

Problem #1...The delay settings in the MiniDSP 10x10 won't go high enough to cover using an FIR filter up top.

Welp, IIR it is!

 

[Matthew J Poes]

This looks really cool. I can't wait to see measurements.

You might consider the padding resistors as an l-pad to help present a more flat and stable load to the amplifier, as well as possibly to lower noise. What does an impedance chart for the Beyma look like, I'm not personally familiar with the driver. Personally any hiss bothers the heck out of me.

Once you have finished the IIR crossover could you create a phase correcting FIR filter? That should give you much of the same results, it will behave as a linear phase device, produce a square wave, but avoid the delay issues between drivers. I've done this with my own speakers as a test, where the crossovers were passive parts with minimal use of trap filters for response shaping, just proper integration, padding, and impedance flattening. Then final response shaping and phase was addressed in DSP. My speakers use three trap filters on the tweeter for response shaping, so to test, I removed those and added them in the processing, along with the phase correction. Minidsp has a link to the phase correction software I used.