fe167e dustcap fase plug

[then_dude]

hello,

i have just removed my dustcap of my fe167e: it is a bob brines ft1600 mkII. I must say, the change is BIG;
i was changing amps and still i thought of the speaker of being way to nasal, to much shouting. I removed the dustcap cause i didn't wanna listen anymore to the speaker (and if something went wrong i would leave this speaker behind). but now it is very very impressive. never thought that such a little thing could make so much difference.

the shouting is gone; i don't feel less weight in the lower frequency; nor do i find that the highs are less either, it is just that the sharp shouting sound is gone.

i might put in some phase plugs, does anyone has some info on making them yourself: i think they are around 1" or maybe a bit less (so that they don't touch the membrane). or can i fill up the gap with something ? and if so what?

anyway: thought to let the world know that this little mod is pretty impressive. i was looking for a long time to build someting else, now i don't know

greetz

[chrisb]

Originally posted by then_dude
hello,

i have just removed my dustcap of my fe167e: it is a bob brines ft1600 mkII. I must say, the change is BIG;
i was changing amps and still i thought of the speaker of being way to nasal, to much shouting. I removed the dustcap cause i didn't wanna listen anymore to the speaker (and if something went wrong i would leave this speaker behind). but now it is very very impressive. never thought that such a little thing could make so much difference.

the shouting is gone; i don't feel less weight in the lower frequency; nor do i find that the highs are less either, it is just that the sharp shouting sound is gone.

i might put in some phase plugs, does anyone has some info on making them yourself: i think they are around 1" or maybe a bit less (so that they don't touch the membrane). or can i fill up the gap with something ? and if so what?

anyway: thought to let the world know that this little mod is pretty impressive. i was looking for a long time to build someting else, now i don't know

greetz

It's probably fair to say that removing the dust cap is only part of the improvement possible with these drivers - ask Bob Brines about the phase plugs he's using.

There's no particular voodoo to them, but dimensional accuracy and squareness of flat bottom is important. For the FE167 & FE166, the diameter is 22.5mm, length approx 40mm, with a bullet-nose shaped taper. Attachment to magnet pole piece by 2 countersunk flat head woodscrews. A skilled lathe worker could turn a pair of these out in fairly short order.





net result should look something like :

[planet10]

Originally posted by chrisb
For the FE167 & FE166, the diameter is 22.5mm, length approx 40mm, with a bullet-nose shaped taper.

Actually with the next batch we are pushing the diameter out to 23mm (but with tighter tolerences)

Your comments about the removal of the dustcap are almost universal but most often accompanied by phase plug installation.

This thread might be of interest.

dave

[serenechaos]

Those that don't have a lathe might be interested in the Steve Deckert trick; using a a vacuum tube as a phase plug.
The pins just stick to the magnet.
As he noted when building his cornerhorns, something along the lines of an old 6dj8 works well in 166/167.

[planet10]

Originally posted by serenechaos
Those that don't have a lathe might be interested in the Steve Deckert trick; using a a vacuum tube as a phase plug.

An idea he poached from (pictures from) one of the VI diyFESTs (IIRC it was Gregg the Geeks inspiration). The pins aren't really enuff to hold the tube in place, it tends to wander. And the innards tend to clatter.

dave

[serenechaos]

Originally posted by planet10
The pins aren't really enuff to hold the tube in place, it tends to wander. And the innards tend to clatter.
dave

Yes, really needs a small piece of steel (or something), fit inside the circle of pins to give more holding power, or it tends to migrate, and eventually rub the cone.
I haven't heard the "innards clatter" as of yet though...

[then_dude]

thanks guys,

good to know how big the plug needs to be.

i' m gonna look at the local diy store looking for something like that.

the sound is enormously better, today a few friend came by, they noticed it immediatly and one of them asked to build one for them, so it is pretty impressive.

i'll be reporting back.

ps: about painting the cone : there the results are more ambigious, some like it , some don't; so i'll need to read more about it.

greetz

[planet10]

Originally posted by then_dude
ps: about painting the cone : there the results are more ambigious,

No ambiguity at all to my ears. Proper treatment makes the FE167 into a completely different (and vastly better) driver.

dave

[then_dude]

thanks planet 10;

well maybe i should take the risk and start painting, cause the dustcap really did it for me, i should try to get everything out of this driver, before even think off building something else.

well i have searched a lot on the internet and this is what i found.

1)you supply the phase plugs (great)
2)there is a EnABL kit that i can buy.

But do i have everything then ?
i don't see mod podge in the kit ?

i'm still a bit in the dark about the painting

1)paint the cone and wizzer with mod podge
2)put on the enabl pattern (with the kit)

3)i also see trifoil pattern, nobody applies this ?


ps: did anybody ever compared a bob brines ft1600mkII with a frugal horn ? (i have seen your signature planet10: that's why ask, if i need to build an fe167e based speaker for friends i might as well build an horn in stead of another bob brines: which i think does a good job)

thanx

[loninappleton]

I just sent for the Enable kit from Ed laFontaine so I'm following these answers closely.

Going back through some EnABL stuff (there's a lot of it) you will see that the trifoil pattern is for the FE127e/126e. The Planet 10 site indicates that both of these have the same pattern.

I have one FE127 with no mods that I can start from scratch on this job.