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dumptruck is finally building ewaves for real

Fantastic. Those 414s are going to be nice. Those are 16 Ohm, right?
I am now on break in jury duty. You are way ahead. I will just try to follow.
:thmbsp:
 
I found PCD to be so inspiring that I've decided to order a mic and USB pre interface right away, in order to attempt the full Zilch method on these. So, I guess that means this build thread will move (even) slower, but with much more data. If only I had a giant stash of crossover components so I could sim and test in one session... I could order a big bag of NPE caps, but no cheap way to get a ton of high power resistors or inductors :(.
 
That's exciting. I love the 414. That's going to be a high end speaker, so I think going the whole way with measuring equipment is a good choice.

Just a note, I have 414Zs as well. If you need any impedance measurements, I have WT2.

Actually, I guess you have that already. Anyway, if you have several threads going on, would you mind putting up links to them here? I have this one bookmarked.
Thanks.
 
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skywave-rider said:
Anyway, if you have several threads going on, would you mind putting up links to them here?
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I don't think I have anything else specific to this project going. Here's one of the cabinets I'm using in its original state:

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Custom-made in the 50s for Bozak B199 woofers. It's 3/4" plywood, lumbercore with rosewood outer layer on the sides and top, 5-ply hardwood back/bottom/front, and solid rosewood trim. Could be stronger, but should be just fine with a little bracing. The woofers just arrived :D.
 
Un baffle:

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Though it looks like a mess in this photo, the waveguide cutout is actually quite precise. This is to be mounted on top of the original baffle, so it will be double-thick except for, unfortunately, the skinny part between woofer and waveguide. I am planning to brace that part, one way or another.
 

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The top is made to fit right under the top of the box I think?

How did you get the corners routed so nice for the QSC?

I was thinking hardwood dowels for bracing between woofer/wg.

Is that a 5" port or is the ID 4"? The roundovers look great. I am considering rear mounting too.

Is there an access panel on the back?

Another question, will you use clamps to hold the woofer from the rear? And will you screw directly into wood, or use some kind of inserts?
 
skywave-rider said:
The top is made to fit right under the top of the box I think? How did you get the corners routed so nice for the QSC?
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Yeah, the waveguide will be flush with the top trim piece on the cabinet (okay, the trim might stick out 1mm or so). If you look at the picture of the cabinet, the new/addtl. baffle goes where the grill is (it is the size of the grill). I routed the edges for the waveguide against a straightedge and then did corners freehand. One will need a touch of filler, but they are pretty good.

skywave-rider said:
Is that a 5" port or is the ID 4"? The roundovers look great.
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5" ID. The port won't be much longer than the 36mm baffle depth, if at all, so a cardboard shipping tube should suffice. Midrange leakage will probably have to be dealt with creatively.

skywave-rider said:
I am considering rear mounting too.
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This is a shallow woofer! Even rear-mounted, z offset looks like about 35mm. I am currently wondering if rear-mounting even deeper is worth testing... probably not.

skywave-rider said:
Is there an access panel on the back?
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The entire back baffle is removable. Er, I guess that would just be called a "panel", but yeah, the whole back comes off.

skywave-rider said:
Another question, will you use clamps to hold the woofer from the rear? And will you screw directly into wood, or use some kind of inserts?
Click to expand...
Good question. Have you mounted these on anything before?
 
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dumptruck said:
Good question. Have you mounted these on anything before?
Click to expand...

On my commercial Altecs with those woofers, they are simply screwed into the rear of the baffle. On my KDTs with JBL123A-1s, I rear mounted with PE clamps, but those screws go right onto the wood. IIRC, one poked through the surface slightly.

I don't know what to say about rear mounting even further back. Since you are obviously good with a router, you could make circles later, the bring it further back, and if I am visualizing it correctly, even extend the roundover. FWIW I like the way rear mounting with a roundover looks.
 
I so rarely choose to paint wood, I forgot how frustrating it can be for a hack like me, even with flat black. Sheesh. Shoulda gone with a texture.
 
Package from PE arrived:

1. Dayton EMM-6 mic: still seems like a crazy steal at $39, prior to using it :D. Response graph looks like about +/- 0.4dB until 3kHz, then more like +/- 1.5dB (and then there's the serialized calibration file).

2. 15' Dayton xlr cable: pretty nice, extremely solid connectors for a cheap cable. Probably should've gone 25'.

3. Pair of cheap-o gold biamp binding post terminal cups (260-281): seem to be lacking any sort of sealing washers on the posts - just adhesive - but they'll do. Fairly handsome.

4. One cheap mic stand (242-743): broken out of the box - the bolt piece threaded for the mic adapter isn't fixed in the boom. Nuts. PE wanted me to check with mfg. first, I did, they wanted a pic of the part in question and the receipt, I sent, they will call me. :dunno:.

USB interface / mic pre is in transit. Cabinet construction is happening now.
 
:yikes: Somebody must've let the drunken monkey use the jigsaw again.

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We'll clean that up, mostly, sort of.
 

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dumptruck said:
One cheap mic stand (242-743): broken out of the box - the bolt piece threaded for the mic adapter isn't fixed in the boom. Nuts. PE wanted me to check with mfg. first, I did, they wanted a pic of the part in question and the receipt, I sent, they will call me. :dunno:.
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The mfg., had me email a few pics. From what I gathered speaking to the support rep, they only made this boom in the stupid way that mine is made for a very short time, i.e. the current boom could not have this problem, and also happens to have a sturdier angle adjuster. They sent me fedex tags to send it to them and will send me a new one. They have been super nice and helpful, but geeze, I am going through all this trouble because I was too lazy to leave the house to buy a used stand locally!! :stupid:

I am not really posting this just to blab. It's for the info, in case someone decides to buy exactly what I bought. Make sure you get the version of the stand without a crimped-on-us-mic-mount-thing. Aside from that, it's much nicer than I thought it would be.
 
Anybody have any thoughts on attaching the second layer of baffle? Though both pieces of wood are nice enough quality, I'm still a little worried about getting voids/vibration if I try to laminate them with glue, down the road if not right away. Plus, it would be nice to be able to remove it and start over if a problem emerges, which would not be fun if I glue it. I have used a layer of cork for this in the past, but that's a little too thick here. I was thinking about a just a coating of plasti dip and a handful of screws?

I think measurements will be underway tomorrow, or even tonight.
 
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