Tysen Variation FE167E with CSS SDX7

[ljfont]

Originally Posted by chrisb

if you're planning on spending much time in DIY realm, the investment in a cheap router and a few bits will more than pay for themselves.

don't be surprised if things take longer than you planned.

best of luck, and keep us posted

chris

I bought a mastercraft router with a bunch of router bits included, and a Jasper jig for cutting holes. Don't know how to use it for 45 deg. chamfers.

And yes, this will take some time to do. Have to work out the bracing for the rear door, and cabing with the movable shelves.

Any suggestions for the rear door and 45 deg. chamfers would be great. Do you know of a good DIY woodworking website?

Will be away on a buisness trip for a month, so I'm trying to get as much done this week.

Thanks again for your help.

[planet10]

Build it. See where you are. Then start skinning the outside. I'd avoid the MDF.

1/2" creates a nice rebate for the SDX7.

A mechanics stethescope is a very useful tool for figuring out where the box is insufficient.

dave

[chrisb]

Originally Posted by ljfont

I bought a mastercraft router with a bunch of router bits included, and a Jasper jig for cutting holes. Don't know how to use it for 45 deg. chamfers.

couldn't be simpler:

Chamfer Bits





These can be used hand held for circles or full perimeter edges, or set up in shop made router table with guide fence for single edges only. In other words, the only bit you use in the Jasper jig is a 1/4" plunge bit, for which it is calibrated. I personally prefer something like an up-cutting spiral bit - if you're planning on more than a couple of pairs of speakers, the quality bits pay huge dividends.








Note that without an extension block, it's too easy to wrap further around an outside corner than you planned. For chamfering the rear side of driver cutouts, you'll need to leave at least a 1/4" depth from the front side for the bearing. This is fine because on most of the smaller drivers, there isn't a lot of margin between the driver cut out and mounting screw holes. Too deep a chamfer and /or flush mounting rebate on the front of the baffle, and you'll not have much core for the hardware.

(there's where you use the MDF - for testing your setup and building the table and jigs/extension blocks. )

IINM, Mastercraft is a Cdn Tire house brand - they might well carry similar bits with their own name. Do not waste money on High Speed Steel bits without bearings for any edge treatment - profile, flush trimming or pattern following.

And yes, this will take some time to do. Have to work out the bracing for the rear door, and cabling with the movable shelves.

Any suggestions for the rear door and 45 deg. chamfers would be great. Do you know of a good DIY woodworking website?

Will be away on a buisness trip for a month, so I'm trying to get as much done this week.

Thanks again for your help.

If you've run out of plywood for bracing, you could use rips of solid lumber such as birch, maple, oak, or even Doug fir. In corners they can be as small as 1x1, and if crossed and interlocked between perpendicular panels, they needn't be any larger dimension than 1x3 (nominal).

[ljfont]

Thanks chris and dave.

Here's the latest update:

- Sub woofer baffle is doubled to 1" total
- Construction is underway, top half is about done.
- I had a 45 chamfer bit in my kit, didn't realize that the bottom was a bearing, I thought this could only be used on a straight edge. duh.. Works great.
- Used T-nuts for the FE167E

Drawing shows about five shelves spaces. Volume starts at about 13L to about 22L

[ljfont]

First time round, the cabinet was overstuffed and it sounded choked. I put a 2" thick packing foam(which is somewhat dense) at the terminus, and used polyfil throughout. I got it balanced good now.

The drivers have been broken in pretty good now from my previous TQWT. So, initial thoughts are Wow, the transients and attacks have returned. Percussion and drums sound more realistic to me now. String plucking and bass slaps are more present. It's like I could hear the bow of a violin hit the first string, or that initial burst of air from Miles. It seems that the driver is not required to move as much air as it did before in this smaller taper, which also makes sound a bit more relaxed and even. The terminus velocity is a lot higher than my original TQWT. See plots.

I don't have the BSC connected, not sure if im gonna need it with the SDX7.

The LF is not as low as my original TQWT, but the attacks are there. Kick drums fundamental are at around 100Hz, and the velocity at the terminus is around 100Hz as well, which may explain this too.

I'm enjoying the sound of these, can't wait to hear them with the SDX7's in the room. Need to finish my XO now.

[ljfont]

Originally Posted by planet10

A mechanics stethescope is a very useful tool for figuring out where the box is insufficient.

dave

I think i learned something about stuffing today. I put my ear on the cabinet and listened to the sound of the music, when I moved my ear around the cabinet, I could hear really bad ringing in places. At that point I would add a bit more stuffing. They were usually around the corners. I think a stethoscope could be more useful for this.

[ttsto]

One thing bothers me, you combine a high sensitivity speaker like FE167E with a low sensitivity woofer...9db difference...how will this be compensated? by reducing the sensitivity of the high sensitive driver I presume...

[planet10]

If you want to go passive the woofer(s) really need to be more efficient than the mid-tweeter. Otherwise you really should bi-amp. I do not like the idea of padding the mid-tweeter at all.

dave

[ttsto]

Eminence ALPHA 8" will work better from this point of view?

[planet10]

TO match up with FE167 using a passive XO, you'd need woofers with an efficiency of at least 95-96dB.

dave