Half Chang build

[gallileo1982]

Yes I already have them.

 

[Scottmoose]

I would use a higher rated resistor. If you can't get higher rated resistors, parallel a couple of the 5w to give the target value with increased power handling.

DCR of the inductor would normally be a bit high; I don't know what your amplifier is, but if its a conventional solid state or PP valves, the extra series resistance will likely be useful, so should be fine.

 

[gallileo1982]

Hi all,
Let me present my Half Changs Fostex FE206En, finally completed yesterday.
Initially built with an exotic plywood, which didn’t look well, so I covered them by oak veener and finished with hardwax.
Now playing with 3.6R resistor, but going to add an 1mH inductor to smoothen mids and hights.
I have read whole the thread looking for the mods and I found a few.
Could you guys please share your thoughts which mods are most impacting the sound, best to start with them?

 

[Jim Shearer]

@gallileo1982,

Besides proper lining of the cabinet, you really need Baffle Step Correction. BSC makes a huge difference in the sound for a HC w/ FE206 driver. Notes from my build in 2008 using the FE206e:
--Baffle step circuit (BSC) consists of 1 mH inductor in parallel with 5 ohm, 12 watt Mills resistor on the positive lead of the driver.

I would not have tried this build with the FE206e instead of the FE207 which Scott designed the HC for, except that I listened to Bob Trancho's Build with the FE206e and found it very enjoyable.

Cheers, Jim

 

[gallileo1982]

Thanks Jim.
That’s what I’m going to do - add the inductor.
Did you try by the chance phase plugs?

Cheers

 

[Jim Shearer]

No, never tried phase plugs. Could never bring myself to cut into the cone/dust cap. I did use the 'bearded' whizzer tweek on a pair of FE167e drivers though. Just a little fiber fluff between the whizzer and the main cone toned down a small resonance that bothered me.

Cheers, Jim

 

[gallileo1982]

I have the same concern as to cutting out the dust cup.
Could you post a picture of the whizzer tweak?
Also, what the wire gauge inductor have you used in the BSC?

 

[Jim Shearer]

Here is a photo of the FE167e with Parts Express AcoustaStuf fiber damping around the whizzer; it is well teased out, and nothing extra to hold it in, so it needs to be gently pushed back into place from time to time.

As far as I can remember, the 1.0 mH air core indictors were 18 gauge.

Cheers, Jim

 

[gallileo1982]

Hi Jim,

thanks for the picture.
I'm going to try with a window foam stripe seal, should do the same job.
Also awaiting the parcel with inductor, very curious how will it impact the sound.

Cheers!