Finished up Wilson'ish MTMW speaker

[Jed]

We have been working on this speaker for some time now. And my friend is very happy with the results, since he will be the proud owner. The midranges are eton 4-300, tweeter is focal kevlar TC120, and woofer is a custom Eton 8-472 we got from someone on ebay. Crossover is around 2K fourth order, and 300 second order acoustic.

Overall, I like how MTMs sound, but they have a very strong presence and clarity that takes some getting used to. I think the focal kevlar is a bit harsh at times, but overall this system offers a lot of clarity. I had fun building it and helping out my friend. Let me know what you think of it or if you have any questions.

Jed

[dynamowhum]

Nice more pictures if you could please?

[Jed]

Nice more pictures if you could please?

I've got a bunch like the one above- same angle. My friend Josh picked them up to take home today so unfortunately I didn't take more.

[BobEllis]

You might try a small inductor in series with the tweeter to get a bit of roll off in the top end. I agree they can be a bit harsh as the response rises about 5 dB in the top octave and a half. Start with around 10 uH, with a bit of resistance in parallel to make a shelving filter - much like a baffle step compensation circuit.

Another option as used in a Zalytron kit is a 1 uf capacitor in the parallel leg of the L-pad in series with the resistor. This has a similar shelving effect.

Depending on which of the three kevlar models you have it probably should be crossed higher. All were recommended at >3Khz, but that was with a second order electrical filter. I used 2.4 kHz, 4th order electrical with a 5 db shelving high pass and it worked pretty well. Not quite as nice as the T120TD5, but close. If your filter isn't at least 3rd order electrical, consider changing it to a higher order.

You should consider some felt around the drivers to create a pseudo flush mount if you can't rabbet the cutouts for flush mounting.

[Nichol1997]

You might try a small inductor in series with the tweeter to get a bit of roll off in the top end. I agree they can be a bit harsh as the response rises about 5 dB in the top octave and a half. Start with around 10 uH, with a bit of resistance in parallel to make a shelving filter - much like a baffle step compensation circuit.

Another option as used in a Zalytron kit is a 1 uf capacitor in the parallel leg of the L-pad in series with the resistor. This has a similar shelving effect.

Depending on which of the three kevlar models you have it probably should be crossed higher. All were recommended at >3Khz, but that was with a second order electrical filter. I used 2.4 kHz, 4th order electrical with a 5 db shelving high pass and it worked pretty well. Not quite as nice as the T120TD5, but close. If your filter isn't at least 3rd order electrical, consider changing it to a higher order.

You should consider some felt around the drivers to create a pseudo flush mount if you can't rabbet the cutouts for flush mounting.

I too have just finished a three-way system using this same tweeter. I am using a 24dB active crossover at 2.7kHz. I find with a lot of my cd's that I am constantly adjusting the volume of the tweeter. I don't know if it sounds harsh or just louder with certain material. I think it sounds a little thin; this may be a result of the actual cd.

I am running an all vacuum tube set-up. The amps, crossover, and preamp are all vacuum tube. Is the T120TD5 suppose to sound better than the kevlar tweeter?

[Jed]

You might try a small inductor in series with the tweeter to get a bit of roll off in the top end. I agree they can be a bit harsh as the response rises about 5 dB in the top octave and a half. Start with around 10 uH, with a bit of resistance in parallel to make a shelving filter - much like a baffle step compensation circuit.

Another option as used in a Zalytron kit is a 1 uf capacitor in the parallel leg of the L-pad in series with the resistor. This has a similar shelving effect.

Depending on which of the three kevlar models you have it probably should be crossed higher. All were recommended at >3Khz, but that was with a second order electrical filter. I used 2.4 kHz, 4th order electrical with a 5 db shelving high pass and it worked pretty well. Not quite as nice as the T120TD5, but close. If your filter isn't at least 3rd order electrical, consider changing it to a higher order.

You should consider some felt around the drivers to create a pseudo flush mount if you can't rabbet the cutouts for flush mounting.

Thanks Bob- those are all good suggestions. I had 3rd order electrical on the tweeter for a bit, but didn't like the sound. So we went to a simpler circuit that yielded an identical slope. Actually, now that I think of it, the crossover point was actually closer to 2.2-2.3k, so hopefully my friend won't push it too much with the volume control and stress the tweeters. My measuring equipment is useless above 15K, so your suggestion of a trap for the top octave is a good one, maybe I'll try it if my friend complains :-).

[Nichol1997]

Just a quick shot.

[Jed]

Just a quick shot.

Nice veneer. That's one thing I haven't tried yet. You could always swap out your kevlar tweeters for the TD5s and see what you think. I think most people prefer the TD5 but I could be wrong. I used to have a pair of the titanium uncoated version and those were some dynamic tweeters. Wish I still had them.

Jed

[Jed]

You should consider some felt around the drivers to create a pseudo flush mount if you can't rabbet the cutouts for flush mounting.

Yeah, I couldn't use my router because of the angled front baffle. Felt should do the trick and maybe get rid of the 3DB dip around 8-9k. Diffraction artifact?

[cobbpa]

Looks good jed! Don't forget I still owe you drinks or dinner if you're ever in Ohio :W

[JonMarsh]

Thanks Bob- those are all good suggestions. I had 3rd order electrical on the tweeter for a bit, but didn't like the sound. So we went to a simpler circuit that yielded an identical slope. Actually, now that I think of it, the crossover point was actually closer to 2.2-2.3k, so hopefully my friend won't push it too much with the volume control and stress the tweeters. My measuring equipment is useless above 15K, so your suggestion of a trap for the top octave is a good one, maybe I'll try it if my friend complains :-).

My experience with the TD120dx2 is that at 2.2 to 2.5 kHz they will handle a lot of SPL with a 3rd order, that's partly because they're so efficient- almost 93 dB.

The older Kevlar version is problematical due to the cone resonance and peaking- your friend might find it more worthwhile to pick up a pair of the newer TC120's from Zalytron, as I think they'll be easier to optimize to a pleasing sounding crossover. I've heard they still have a number of pairs left. ThomasW and I still have a few pairs left, and measuring them with Praxis is on my long and long delayed to-do list.

[ThomasW]

Zalytron has them for the astounding price of $90ea.... 8O

[Jed]

Looks good jed! Don't forget I still owe you drinks or dinner if you're ever in Ohio :W

Thanks Cobbpa. Being that I live in Rochester, NY area, it might be awhile until I get over to Ohio. Glad you are enjoying those speakers still.
Jed

[Jed]

Zalytron has them for the astounding price of $90ea.... 8O

For half the price I'm looking at Neo3pdr or the new peerless HDS.