Tweet
So I bought a pair of these a few months ago because I was going to redesign my Delphi and wanted to use a more robust mid dome. I had a feeling these would be good performers and if you've seen Zaph's recent measurements they are really incredible dome mids. Two problems with them though, the AC is too far forward and it has a dip around 2khz. My hope is that by putting it a waveguide similar to the legendary ATC dome mid we can cure at least the first problem, and possibly the second.
The waveguide is basically a truncated 1 1/4" roundover. I got the bit at mlcs I think. This should be very similar to the ATC roundover. Now the ATC waveguide actually ends on the outside of the surround, but I opted to bring it in closer to the dome similar to the Morel MDM55 and Seas T25CF001 I used for guidance. This is possible because, unlike the ATC, the TB uses an inverted surround. But with 1.5mm xmax and the little VC leads we do still have to be careful.
The following is teh step by step method I used to make the waveguide. I can't just give you the measurements because this is a truncated roundover, so the process was somewhat iterative. It took 3 mock-ups to get to the final design. This is sort of the perfectionist design. I'll give a brief description of an easier design that may or may not be as good. Overall diameter is 5 1/2" inches and the dome top is just flush with the baffle plane.
First this is based on a baffle 1 1/2" thick. Just two 3/4" MDF sheets glued together. Pretty typical for a front baffle. I will be using the backside of the baffle to drill our hole for the Jasper jig since everything is referenced to the backside and the roundover bit bearing will ride on this part of the baffle. If you drilled the hole from the front it may wonder a 1/16" and really screw the whole thing up.
1) We'll make three cuts 3/4" deep at 5 9/16", 5 1/16", and 4 9/16". It should like this when done:
2) Next I made another 3/4" deep pass at 3 1/16" like this:
The 1/2" or so strip in between the grooves will be routed down at the very end. We need this for now so the roundover bit bearing has something to ride on.
3) Now I flipped the baffle over and cut a matching 3/4" deep groove at 3 1/16" and removed the center plug:
4) This front cut may not have matched the back cut due to the slight wander when we drilled the pilot hole. No worries though as the front will be routed away. Which we do next:
5) Now that we don't need the guide for the router bit we can route down that strip in the second picture. But not all the way. This is where the perfectionist part comes in. I left it about 1/8" higher than the three cuts made for the driver flange:
6) Then I took a marker and marked a roughly 1/8" (at most) line around the strip. I then routed the rest of the strip flush with flange cut, leaving the black marked portion behind:
7) I put some gasket tape on the driver:
8) And mounted it on the baffle:
Now the black strip is there so that the edge of the waveguide is closer to the base of the dome, about where to where the surround attaches to the dome. The less perfectionist way would be to cut a 3" circle in step 2 and 3. In step 5 route the strip flush with rest of the flange cut and call it good.
Measurements to follow.
The waveguide is basically a truncated 1 1/4" roundover. I got the bit at mlcs I think. This should be very similar to the ATC roundover. Now the ATC waveguide actually ends on the outside of the surround, but I opted to bring it in closer to the dome similar to the Morel MDM55 and Seas T25CF001 I used for guidance. This is possible because, unlike the ATC, the TB uses an inverted surround. But with 1.5mm xmax and the little VC leads we do still have to be careful.
The following is teh step by step method I used to make the waveguide. I can't just give you the measurements because this is a truncated roundover, so the process was somewhat iterative. It took 3 mock-ups to get to the final design. This is sort of the perfectionist design. I'll give a brief description of an easier design that may or may not be as good. Overall diameter is 5 1/2" inches and the dome top is just flush with the baffle plane.
First this is based on a baffle 1 1/2" thick. Just two 3/4" MDF sheets glued together. Pretty typical for a front baffle. I will be using the backside of the baffle to drill our hole for the Jasper jig since everything is referenced to the backside and the roundover bit bearing will ride on this part of the baffle. If you drilled the hole from the front it may wonder a 1/16" and really screw the whole thing up.
1) We'll make three cuts 3/4" deep at 5 9/16", 5 1/16", and 4 9/16". It should like this when done:
2) Next I made another 3/4" deep pass at 3 1/16" like this:
The 1/2" or so strip in between the grooves will be routed down at the very end. We need this for now so the roundover bit bearing has something to ride on.
3) Now I flipped the baffle over and cut a matching 3/4" deep groove at 3 1/16" and removed the center plug:
4) This front cut may not have matched the back cut due to the slight wander when we drilled the pilot hole. No worries though as the front will be routed away. Which we do next:
5) Now that we don't need the guide for the router bit we can route down that strip in the second picture. But not all the way. This is where the perfectionist part comes in. I left it about 1/8" higher than the three cuts made for the driver flange:
6) Then I took a marker and marked a roughly 1/8" (at most) line around the strip. I then routed the rest of the strip flush with flange cut, leaving the black marked portion behind:
7) I put some gasket tape on the driver:
8) And mounted it on the baffle:
Now the black strip is there so that the edge of the waveguide is closer to the base of the dome, about where to where the surround attaches to the dome. The less perfectionist way would be to cut a 3" circle in step 2 and 3. In step 5 route the strip flush with rest of the flange cut and call it good.
Measurements to follow.
ops: and now what do I have to say for myself... :roll:
Looks like the little overhang (and some foam for good measure?) that I showed in the walkthrough of the first post is required. Kind of a PITA but if I can do it anyone can. My woodworking skills are pretty weak. The good thing with all this experimenting is finding out that many typical methods do not work at all. Should prevent someone else the headache of wasted attempts with this driver in the future.
Comment