loninappleton said:
Ya I think Alex is right here. As I understand it, the whole point is to remove or fill the cavity behind the dust cap and the inside of the former. It more than just a pretty pointy thing.
Alex from Oz said:
No, I just thinking of how I would do it if there was no lathe available. My buddies Dave and Scott (planet10 and SCD) have looked after my needs thus far.
Cal Weldon said:
If the plastic cap is hollow -- our 1st prototype was from Chris' daughter's lipstick -- just fill with ductseal or bluetac and embed a coupld bolts sideways into the goo.
dave
Lipstick holders.
Smack, I should have had a V-8.
Ok, nix the pen caps.
To rough in the shape and since the one dowel size of 5/8 or whatever it was fits nearly perfectly it makes more sense to me to rough in the shape with the eggs. Then a Dreml tool or something with the phase plug chucked into a drill could be used for shaping.
After sawing one of those eggs with a hack saw and the egg in a Vice Grip and then cutting the dowel to size in a hand miter box and trying to keep everything square it'll be a number of days if ever that I try to fine tune it any more.
The length is actually more like 1.5 inches over all. A little wood putty
provides a surface to do some smoothing and getting the centering of the tip right. I haven't done a good listening test yet.
Last point: I've gotten at least reasonably good at removing the dust cap so that 50% has been going smoothly.
Smack, I should have had a V-8.
Ok, nix the pen caps.
To rough in the shape and since the one dowel size of 5/8 or whatever it was fits nearly perfectly it makes more sense to me to rough in the shape with the eggs. Then a Dreml tool or something with the phase plug chucked into a drill could be used for shaping.
After sawing one of those eggs with a hack saw and the egg in a Vice Grip and then cutting the dowel to size in a hand miter box and trying to keep everything square it'll be a number of days if ever that I try to fine tune it any more.
The length is actually more like 1.5 inches over all. A little wood putty
provides a surface to do some smoothing and getting the centering of the tip right. I haven't done a good listening test yet.
Last point: I've gotten at least reasonably good at removing the dust cap so that 50% has been going smoothly.
Inconclusive
I made a setup and balanced everything I could as closely to a mirror pair including wire that I could.
Such a test fore me was inconclusive because something might be going in my solid state RP U100: one side seemed louder and so not a very good test.
The one thing I got out of the test was that the phase plug treated Pioneer was more muted. Again this might have been due to a
faulty amp.
Suggestions for fixing the phase plug length based on those posted specs above welcome.
Needless to say that I'm not ready to cut into my FE127e's or the new 167e.
I made a setup and balanced everything I could as closely to a mirror pair including wire that I could.
Such a test fore me was inconclusive because something might be going in my solid state RP U100: one side seemed louder and so not a very good test.
The one thing I got out of the test was that the phase plug treated Pioneer was more muted. Again this might have been due to a
faulty amp.
Suggestions for fixing the phase plug length based on those posted specs above welcome.
Needless to say that I'm not ready to cut into my FE127e's or the new 167e.
Inspired by your investigation, I chopped off the dust caps on the old speakers we use to listen to TV.
Seemed to open things up even without phase plugs.
I still haven't gotten the courage to do my FE167E either.
What box are yours in?
Cheers,
Alex
Seemed to open things up even without phase plugs.
I still haven't gotten the courage to do my FE167E either.
What box are yours in?
Cheers,
Alex
Alex from Oz said:
The 167e is still in break in. I have one. The goal is to use a test box
I made with scraps to hear what it sounds like. The goal is to make an MLTL. My preferred design is the design with a port firing out the bottom. Then getting the speaker position and down firing port as close to ear level that works out. Actually GM says having the placement above ear level gives a "concert hall" ambience.
I've come to listen to classical music with one BIB and one MLTL: MLTL left and BIB right. This just comes from building one test style at a time and now having the present arrangement.
As to the plugs, I might have a different result back here in the shop. The shop turns out to be a more satisfying room. All the details of how I have a shop from a converted bedroom in an apartment building would have to be taken to mail.
The 167e was for me the next step up in improving the MLTL side.
Now that you have a test subject and know what it feels like to
cut a dust cap, might as well go the rest of the way. I'm told that if you don't have a way to get Damar Varnish, there's an alternate product. It's called Aquanet-- available at the drug store in the
cosmetic hairspray section.
But brushing on will work way better. See the thread called Enabl kit. It is not very long and is in Market Place here on DIY Audio Forum where Bud has the
required products for sale as a kit.
Last thing on Damar: If you have Hobby Lobby and Michaels, pick Hobby Lobby. The Damar costs half as much for the same size jar.
But I have no idea how the hobby shops work Down Under.
Hobby Lobby has the eggs too.
g'day.
😉
Only one FE167E??
My pair of FE167E took 100 hours to become listenable but really needed over 200 hours to really open up (to my ears).
I used Damar varnish some time ago on my RS 40-1354A’s.
I'm torn between using damar or the puzzlecoat that Dave from planet10 uses.
The EnABL kit is on my christmas list.
I actually EnABL'd my drivers using aluminium foil and double sided tape some time ago.
I removed it from the driver so I could focus on exploring EnABL in ports, baffles and inside speaker cabs.
Cheers,
Alex
My pair of FE167E took 100 hours to become listenable but really needed over 200 hours to really open up (to my ears).
I used Damar varnish some time ago on my RS 40-1354A’s.
I'm torn between using damar or the puzzlecoat that Dave from planet10 uses.
The EnABL kit is on my christmas list.
I actually EnABL'd my drivers using aluminium foil and double sided tape some time ago.
I removed it from the driver so I could focus on exploring EnABL in ports, baffles and inside speaker cabs.
Cheers,
Alex
Yes, only one. If it is amazing, Madisound is very close by here in Wisconsin US. Only about 100 miles away.
I have the 167e in a cardboard box and give it the white noise treatment when I leave. I don't leave for long periods so that is still going on.
Last winter I tried using 2 floor standers: A Harvey and a BIB
with unsatisfactory results. During the various building processes and out of necessity, I began using one of each: BIB and MLTL.
I have the 167e in a cardboard box and give it the white noise treatment when I leave. I don't leave for long periods so that is still going on.
Last winter I tried using 2 floor standers: A Harvey and a BIB
with unsatisfactory results. During the various building processes and out of necessity, I began using one of each: BIB and MLTL.
Homebrew phase plug
This thread caught my attention at the beginning, but somehow it seemed there's not a single picture of a "homebrew phase plug" and the discussions turned to other direction...
OK, anyway... I've been quite busy on my own system lately, including the 'midrange driver' derived from a "fullranger".
This was an 8" fullranger I bought from local audio shop. It came with paper cone and paper whizzer, quite a smooth and sweet sounding unit. Used with open baffle for a while in a small room, and stored away. I dug it out and made it the "midrange" of my newly developed 3way OB.
Being a midrange, its whizzer is not needed anymore, so it's cut, together with the paper dust cap. OTOH, I happened to acquire a piece of balsa wood which was lathed as a rod.
Looking at both, the balsa rod seemed fit in the pole piece of the driver! How convenient! But the balsa rod was actually slightly largher than the voice coil former, thus can't be fitted in.
Fortunately the balsa is so soft and easy to work with. By just knife and sand paper, I managed to rubbed off a layer, shrank the diameter a little, and shape it into a bullet:
Fitted onto the pole piece of driver by 3 wood screws and magnet attraction:
It's quite a tight fit. The gap between former and plug is less than 1mm.
The sound seemed smoother but not changed very much -- I don't use it all the way to the top, though. Maybe this makes it not so significant. Looks pretty anyway😀
This is the midrange with the tweeter WG:
This thread caught my attention at the beginning, but somehow it seemed there's not a single picture of a "homebrew phase plug" and the discussions turned to other direction...
OK, anyway... I've been quite busy on my own system lately, including the 'midrange driver' derived from a "fullranger".
This was an 8" fullranger I bought from local audio shop. It came with paper cone and paper whizzer, quite a smooth and sweet sounding unit. Used with open baffle for a while in a small room, and stored away. I dug it out and made it the "midrange" of my newly developed 3way OB.
Being a midrange, its whizzer is not needed anymore, so it's cut, together with the paper dust cap. OTOH, I happened to acquire a piece of balsa wood which was lathed as a rod.
Looking at both, the balsa rod seemed fit in the pole piece of the driver! How convenient! But the balsa rod was actually slightly largher than the voice coil former, thus can't be fitted in.
Fortunately the balsa is so soft and easy to work with. By just knife and sand paper, I managed to rubbed off a layer, shrank the diameter a little, and shape it into a bullet:
Fitted onto the pole piece of driver by 3 wood screws and magnet attraction:
It's quite a tight fit. The gap between former and plug is less than 1mm.
The sound seemed smoother but not changed very much -- I don't use it all the way to the top, though. Maybe this makes it not so significant. Looks pretty anyway😀
This is the midrange with the tweeter WG:
Re: Homebrew phase plug
Thanks for the picture. I am camera challenged not owning one
and this hobby is done by me with the absolute minimum. Necessity dictates that if I'm going to build anything I don't take pictures of it.
If indeed your phase plug is in there tight, how does the cone excursion work? After having done a couple of these and had reported here that there is a certain amount of fiddling with the plug to be done to avoid contact with the cone, how have you managed?
I am going to switch out one of these Pioneer with the plug back to one which is simply Damar'ed. I like very crisp audio which means that I stick with solid state and am shooting for a tri path amp to
get some classical music broadcasts out of my computer.
Room effects seem to play a big part in what I'm doing at the moment.
If I make the right sort of jig to trim the plug then maybe
the correct length would improve the perceived lack of clarity in the phase plug treated unit. I measured the wild guess completed plug to be 37 mm.
Perhaps the effective length is given at Planet 10. I haven't checked there but will try that now.
Thanks for the picture. I am camera challenged not owning one
and this hobby is done by me with the absolute minimum. Necessity dictates that if I'm going to build anything I don't take pictures of it.
If indeed your phase plug is in there tight, how does the cone excursion work? After having done a couple of these and had reported here that there is a certain amount of fiddling with the plug to be done to avoid contact with the cone, how have you managed?
I am going to switch out one of these Pioneer with the plug back to one which is simply Damar'ed. I like very crisp audio which means that I stick with solid state and am shooting for a tri path amp to
get some classical music broadcasts out of my computer.
Room effects seem to play a big part in what I'm doing at the moment.
If I make the right sort of jig to trim the plug then maybe
the correct length would improve the perceived lack of clarity in the phase plug treated unit. I measured the wild guess completed plug to be 37 mm.
Perhaps the effective length is given at Planet 10. I haven't checked there but will try that now.
Just an update.
Here at Planet 10
http://www.planet10-hifi.com/FE127.html
It says that phase plugs are hard to work with on the 127's and 126's and show little improvement.
No measures for the Pioneers I have (which are now discontinued) but this tells me not to mess with my 127's for this procedure.
If all this is of interest, readers will want to check out the extreme basket mods thread as well.
Here at Planet 10
http://www.planet10-hifi.com/FE127.html
It says that phase plugs are hard to work with on the 127's and 126's and show little improvement.
No measures for the Pioneers I have (which are now discontinued) but this tells me not to mess with my 127's for this procedure.
If all this is of interest, readers will want to check out the extreme basket mods thread as well.
Hi,
Some more pictures:
Inside the voice coil former and in front of the center pole piece, there is a cylindrical space. So it's 'straight-sided'. The contour of phase plug also has a section of this straight side. So, even the gap is very small, they don't rub. On the last picture above, you may see the gap at the upper left side is slightly larger (still small, though), and in other portion of the circle, they seems touched. No, they don't touch. It's because of the shooting angle and len's distortion.
Like planet10, I also use screws on the back of phase plug and make them flush (as possible). By the attraction of the pole piece, it can be fixed properly and also movable -- pretty handy in adjusting the position.
In fact my phase plug isn't perfectly round, the gap is not constant along the circle. I'm OK with this imperfection.
Some more pictures:
Inside the voice coil former and in front of the center pole piece, there is a cylindrical space. So it's 'straight-sided'. The contour of phase plug also has a section of this straight side. So, even the gap is very small, they don't rub. On the last picture above, you may see the gap at the upper left side is slightly larger (still small, though), and in other portion of the circle, they seems touched. No, they don't touch. It's because of the shooting angle and len's distortion.
Like planet10, I also use screws on the back of phase plug and make them flush (as possible). By the attraction of the pole piece, it can be fixed properly and also movable -- pretty handy in adjusting the position.
In fact my phase plug isn't perfectly round, the gap is not constant along the circle. I'm OK with this imperfection.
I can tell just by the proportions that the one I have is too long.
These descriptions are very helpful. If the side is tapered in true bullet fashion that should clear the opening.
If I wanted to proceed with the process I'd work on the sides, give it some taper first and then re-cut the length. I'm just using a wadded up piece of sandpaper for shaping.
These descriptions are very helpful. If the side is tapered in true bullet fashion that should clear the opening.
If I wanted to proceed with the process I'd work on the sides, give it some taper first and then re-cut the length. I'm just using a wadded up piece of sandpaper for shaping.
I think you should keep it straight in the range where plug and voice coil former overlap. So they keep the gap width when the cone (and former, of course) moving in and out. If the plug is tapered 'within' the former, there would be pumping action here, which must be a bad thing.
In our application, the stroke of the driver is short. So the taper of the plug is OK to start more or less where it protrude the former.
I remember the phase plugs of some midbass drivers have that straight portion slightly longer - the taper start at several mm away from the former. I believe this is to avoid that 'pumping' between former cylinder and plug when long stroke is needed.
See this:
Pic from: http://www.avmagazine.it/forum/showthread.php?t=62236&page=2
And, of course: http://www.diyaudio.com/forums/showthread.php?postid=1674236#post1674236
In our application, the stroke of the driver is short. So the taper of the plug is OK to start more or less where it protrude the former.
I remember the phase plugs of some midbass drivers have that straight portion slightly longer - the taper start at several mm away from the former. I believe this is to avoid that 'pumping' between former cylinder and plug when long stroke is needed.
See this:
An externally hosted image should be here but it was not working when we last tested it.
Pic from: http://www.avmagazine.it/forum/showthread.php?t=62236&page=2
And, of course: http://www.diyaudio.com/forums/showthread.php?postid=1674236#post1674236
cotdt said:
I have seen this done some time in the past. Breakage would be a concern esp for experimenters such as myself who are taking things apart all the time.
That tip about the lipstick tube is about the best one so far as a ready-made. Unfortunately I don't know one lipstick tube from another.
cotdt said:
A tube has all sorts of bits inside that will vibtate and add their own (unwanted) sound to the mix.
dave
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