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D220Ti: what mods can be done?

Yeah, you could make it look like the St. Louis arch

Great idea 4343. As for the big caps you have, they would actually be reducing cab volume. Which is OK is you can spare it.
 
djnagle said:
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Great idea 4343. As for the big caps you have, they would actually be reducing cab volume. Which is OK is you can spare it.
Click to expand...

Tanks.

I've taken a few ideas from this thread today, some before even reading them!

So, I built a pair of Karlson 12" cabs a few years back, put EV 8HD's in nice matching boxes to sit on top... (Hold that thought a bit...)

Last year I built new top boxes for a pair of Pyle 6.5X12 waveguides, with D220Ti. Inside I put a >95 EW XO. (Hold that thought over next to the other one for a bit...)

Today I took them apart and replaced the 1.5uF's with a pair of 3uF's standing on their ends, the middle being tied to a 2.2M ohm resistor.
Then I took out the 4.7uf and replaced it with a 10uf and a 9.5uF (all I had on hand), standing on their ends, the middle being tied to a 2.2M ohm resistor. The two resistors are tied together and fed to a 9V battery box, positive side. The negative side of the battery is tied to ground at a convenient point, which was the wire feeding the L-Pad in my case. (Pin 3 IIRC.) After playing them for a few CD's worth of time over dinner, I slipped a 9V into the battery box. Playing Dire Straights through one* of them now. Sounds wonderful!:music: Tomorrow I will do the same to the other, but I will have to wait for some 9.1uF's to get a stereo pair.

So the answer to the question about fitting them onto the circuit board is, change values to double what you have now. <95 =4.7uf and .47uf, the CC schematic shows this as 9.1uF+10uF and 1.0uF+1.0uF, vertically, they should fit.

* The other side is my LE-10A with 8X8 waveguide the Zilch was kind enough to post a crossover for somewhere.:tresbon: I've got them running bi-amped, so it was a simple matter to unplug the HF cable and plug it into the top box. C-C? Huge! Which is why I gave up on the Karlson cabs so long ago...
 
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djnagle said:
Yeah, you could make it look like the St. Louis arch

Great idea 4343. As for the big caps you have, they would actually be reducing cab volume. Which is OK is you can spare it.
Click to expand...

Great minds think alike,eh? St Louis Arch it is. I went back today and got 4 more oil caps, but I don't think they will fit in the top box with the waveguide, the driver and the crossover. I did find a bag of mylar 10uF's today, and a bunch of 4uF's, so that will almost have to be what I go with.

And another method I've used before is to make a small board (literally some 1/8" or 1/4' ply, masonite, Pergo, any board!) to mount the caps on. I just drill holes for the wires, solder on the back, then run wires over to the main circuit board to the original holes. (I did a pair of Charge-Coupled 4412A's last year like that, the 4 50uFs alone were bigger than most of the original board! In all I replaced 12 caps (6 filter, 6 bypass) with 22 IIRC, talk about reducing cabinet volume...)
 
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[EDIT: Just found these posts, which basically answer my questions below:]

http://audiokarma.org/forums/showthread.php?t=150939&page=839

jhoyt said:
I mounted round pieces of thin open cell foam inside the chambers.
Click to expand...

zog666 said:
I've also done the "tweaks" lining the inside of the d220ti's plastic cap.
Click to expand...

Bringing back this thread:
  • Are there any photos of the damping on the inside of the D220Ti chambers?
  • Exactly what materials did you guys use and where did you get them?
  • Would damping them with felt change their frequency response?
  • I assume the back of the chamber just comes off with those four screws, right?
I ask because I'm finishing up my own project for a buddy, and want to damp his compression drivers before handing them over for use. (See my build thread here.)

Thanks!
 
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Zonker, I saw your recent build, and it looks awesome!

For internal damping I used 1/4" upholstery foam, cut to fit, but I would think wool felt would be as good if not better. I used double-sided sticky tape to secure it inside the back of the chamber. Just make sure the damping material can't come into contact with the diaphragm itself. Also, I used rope caulk to damp the exterior of the chamber, as well as to fill voids in the driver's body.

The internal damping doesn't change the drivers' sonic character much. Stock, they are pretty ragged at moderate to loud volumes, but extend to 20KHz. After damping, they are MUCH smoother, in fact they don't get harsh at all. You might lose the top KHz or so of response, but you gain far more in sound quality.

Unfortunately, I didn't take any pictures when I did the mods. And yes, those four screws are it.

Good luck, again your build is fantastic.
 
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Terrific; thanks! Both my buddy and I have "old ears" anyway, so that's fine.

I really appreciate the comments; this was a big project for me and I am really pleased at how it turned out. I honestly didn't expect the "e36s" to look or sound as good as they do. :D

Now I have to tear them down again and store them for transport to San Francisco at the end of March or early April. I figure on damping the compression drivers while they're apart again.
 
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Here is a picture of my rope caulk mod.

Sent from my SPH-D710 using Tapatalk
 

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vtomike said:
Here is a picture of my rope caulk mod.

Sent from my SPH-D710 using Tapatalk
Click to expand...

That's perfect, thanks for the pic!

Have you noticed the same changes I have in the D220Ti's?

Oh, and BE CAREFUL with the connectors on the diaphragm, I ruined one by simply unplugging my wires.
 
My connectors were pretty tight, so I had to wiggle them to get them off. But I had to order a new diaphragm, so I'm glad they're inexpensive!
 
jhoyt said:
That's perfect, thanks for the pic!

Have you noticed the same changes I have in the D220Ti's?

Oh, and BE CAREFUL with the connectors on the diaphragm, I ruined one by simply unplugging my wires.
Click to expand...

Seems to be more detailed and less harsh to my ears.
 
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