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post #1351 of 1538
6/20/12 at 4:18am

Any tips on matching the sensitivity of two drivers ?

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post #1352 of 1538
6/20/12 at 4:59am

You can use an L-pad to drop the sensitivity of a driver. It's basically just a voltage divider made from two resitors.

 

L-pad calculator:

http://www.sengpielaudio.com/calculator-Lpad.htm
 

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post #1353 of 1538
6/20/12 at 5:24am

yes have read about it but not sure if you can use it between 2BA drivers.

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post #1354 of 1538
6/20/12 at 6:18am

Why not? Voltage controls the amplitude with BAs, just like with dynamic drivers. L-pad drops the voltage going to the driver. It functions just like the high/low pass filters, but it has a fixed value across all frequencies.
 

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post #1355 of 1538
6/21/12 at 12:18pm

I have a CI-22955 in a diy universal for testing purposes, which sounds surprisingly good by it self, but I was also wanting to add a ED-29689 for better mids and highs. I was wondering what recommendations anyone would have on what dampers to use as well as if I should add any resisters. 


Edited by Fredrichs - 6/21/12 at 1:17pm
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post #1356 of 1538
6/21/12 at 2:19pm

Red dampers seem to be the popular choice with the CI-22955. I have the driver aswell, but haven't got around to experiment with it yet. Maybe adding a resistor in series, somewhere in the 10-30 ohm range perhaps. It would drop the output by a few dB.

 

Also, since alot of people here use the TWFK, what do you do about the rear port? I was just testing a FED-30048, and having the rear port open made the sound really thin and shrill. Closing it with a piece of electrical tape made the sound so much better.

TWFK has the port aswell, so maybe it could make a substantial difference.

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post #1357 of 1538
6/22/12 at 4:23am
Quote:
Originally Posted by Fredrichs View Post

I have a CI-22955 in a diy universal for testing purposes, which sounds surprisingly good by it self, but I was also wanting to add a ED-29689 for better mids and highs. I was wondering what recommendations anyone would have on what dampers to use as well as if I should add any resisters. 

Check the post #1326. It seems that the ED can't be added to the CI.

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post #1358 of 1538
6/22/12 at 8:15am

I'm sure they could be used together. While the CI might have an opposite phase, you can always reverse the wiring on one of the drivers to correct this.
 

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post #1359 of 1538
6/22/12 at 12:34pm

Thank you for the info. I think I'm going to go ahead any get the ED and see how it turns out. Also apparently the Unique Melody Aero us the CI and the ED so it may work. I would go with the TWFK but the ED is much cheaper.

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post #1360 of 1538
6/26/12 at 7:19am

Is there any website with the detailed pinout of the TWFK?

It seems that the 2 ground pins are connected.. is this true?

 

twfk_pinout.png

 

If this is true, with only 3 connections, the wires inside the shell are easy to accommodate. 

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post #1361 of 1538
6/26/12 at 9:24am

Yes, you are correct. The negative terminals are connected and you only need three wires. You can verify this with a multimeter if you have the driver.  I agree that the datasheet could be a bit more clear on this.
 

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post #1362 of 1538
6/27/12 at 10:17am

have been checking out this thread since last year... read that someone mentioned loctite 3321 is a safe bet for shell and i found this on ebay http://www.ebay.com/itm/Loctite-Medical-/140685694030?pt=LH_DefaultDomain_3&var=&hash=item20c185544e so hopefully it helps someone out there..
 

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post #1363 of 1538
6/27/12 at 10:21am

Anyway does anyone happen to know where did UM source its dynamic driver for Merlin? Will be excellent if a dynamic driver could replace the BAs... --> less tuning and no crossovers? Or maybe just act as a woofer i.e. do a Merlin or superfi. 5 EB (which is difficult).

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post #1364 of 1538
6/28/12 at 4:22pm

Here is my recent project: CI+TWFK

 

edba3.jpg

 

IMG_5675.JPGIMG_5677.JPG

IMG_5682.JPGIMG_5684.JPG

 

great sound!!!! (wood isn't finished, yet)

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post #1365 of 1538
6/28/12 at 4:35pm

Looks good! I thought about using wood aswell, haven't got around to trying yet. I did my covers with polymorph(pretty much the same as shapelock).

 

Judging from the pics, you didn't use any cap on the tweeter of the TWFK?
 

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