I talk smart but I don't own a real router.
I have one of those zip tools that you can
chuck up a router bit in. They come with accessories
that make it into a router, a flush trimmer, circle cutter
and roto saw all with different bits.
I watched for a deal and got it for $20 or so.
Most recent router bit purchase was 5 pieces for
$5 including a 3/8 roundover.
The main need for this is chamfering the back side
of the speaker hole and maybe rebating the front.
http://www.rotozip.com/Shop/CategoryBrowse.htm?HID=188052&BID=19
This shows the brand name accessories-- mine came in a kit.
I have one of those zip tools that you can
chuck up a router bit in. They come with accessories
that make it into a router, a flush trimmer, circle cutter
and roto saw all with different bits.
I watched for a deal and got it for $20 or so.
Most recent router bit purchase was 5 pieces for
$5 including a 3/8 roundover.
The main need for this is chamfering the back side
of the speaker hole and maybe rebating the front.
http://www.rotozip.com/Shop/CategoryBrowse.htm?HID=188052&BID=19
This shows the brand name accessories-- mine came in a kit.
Have you checked the prices for good roundover bits? I'd say you got a deal.
Don't overlook the idea of getting a woodsmith to spin a couple baffles on the lathe. They can cut them down in twenty minutes. It is an easy job for a decent spinner. Just a thought. Good luck everyone with your great builds.
Thanks as always to GM for leading the class. --I'm getting the hang of it Greg. My BIB's are sounding great. (FE168)
I would like to build a BIB for the Altec 604....
Don't overlook the idea of getting a woodsmith to spin a couple baffles on the lathe. They can cut them down in twenty minutes. It is an easy job for a decent spinner. Just a thought. Good luck everyone with your great builds.
Thanks as always to GM for leading the class. --I'm getting the hang of it Greg. My BIB's are sounding great. (FE168)
I would like to build a BIB for the Altec 604....
Re: roto zip?
Time to get back on topic
but I'll just close by saying that before I get any
$26 round over bits and $300 Bosch routers
I'm taking my practice with this cheap stuff.
I'd say for any sort of decent work, real wood
(rather than the particle board I use) is preferred.
These small tools give me a chance for the
feel of doing the work without having a shop.
Better work will result with more horsepower
and a good cutter.
I've been doing this for quite a while and I still
have all eight fingers.
;-)
gychang said:
Time to get back on topic
but I'll just close by saying that before I get any
$26 round over bits and $300 Bosch routers
I'm taking my practice with this cheap stuff.
I'd say for any sort of decent work, real wood
(rather than the particle board I use) is preferred.
These small tools give me a chance for the
feel of doing the work without having a shop.
Better work will result with more horsepower
and a good cutter.
I've been doing this for quite a while and I still
have all eight fingers.
;-)
Hi there!
Finally I have made an effort to fix the highs coming out of the mouths on my Monacor BIB's. I think it was GM that posted that a grill cloth could be put behind the driver. One day, at work when I was filtering a new lacquer, it struck me that these filters would perhaps be ideal for this. They're made of rough polyester in the inside and outside is a more reflecting material. So to say a one way path through filter. It is not possible to filter back way in these.
They are available from 25 to 250 micron. Maybe there's higher grades but don't think it's no use to go higher than 50 or 75 micron.
First test I put different filters in front of the speakers and concluded that I would try the 25 micron. This filter grade provided the highest attenuation of mids and highs.
bib
More is coming...
Finally I have made an effort to fix the highs coming out of the mouths on my Monacor BIB's. I think it was GM that posted that a grill cloth could be put behind the driver. One day, at work when I was filtering a new lacquer, it struck me that these filters would perhaps be ideal for this. They're made of rough polyester in the inside and outside is a more reflecting material. So to say a one way path through filter. It is not possible to filter back way in these.
They are available from 25 to 250 micron. Maybe there's higher grades but don't think it's no use to go higher than 50 or 75 micron.
First test I put different filters in front of the speakers and concluded that I would try the 25 micron. This filter grade provided the highest attenuation of mids and highs.
bib
More is coming...
...as you can see(I hope) the filter is tube shaped. I just cut them at the bottom and attached it with a staple gun on the back of the front baffle. I had a one inch thick BAF wadding behind driver and this went out when trying this wrap-around-driver damping.
I've not been able to listen at higher volumes yet but I think it's better for sure. Voices are not so "fat/thick" anymore.
The first time I listened to them was in a simular room and when I moved them to an office with acoustic tiles, this phenomen disappeared. I got the same difference with the wrap-around damping in my living room. Seems to be a winner for now, however I will spare my final judgement for later. It's too easy to be excited of some changes in sound that may not be so bearable in the long run.
Seems that I'm not able to attach pictures? Been possible before, oh well.....
Cheers
I've not been able to listen at higher volumes yet but I think it's better for sure. Voices are not so "fat/thick" anymore.
The first time I listened to them was in a simular room and when I moved them to an office with acoustic tiles, this phenomen disappeared. I got the same difference with the wrap-around damping in my living room. Seems to be a winner for now, however I will spare my final judgement for later. It's too easy to be excited of some changes in sound that may not be so bearable in the long run.
Seems that I'm not able to attach pictures? Been possible before, oh well.....
Cheers
Ghost in the machine again, 
I know the feeling -we've all been there I'm sure; cautious after making a change until we've got used to the difference. I imagine it will indeed be a positive step forward though for you as you mention the effect is similar to those you've had before with other things.
Regards
Scott
I know the feeling -we've all been there I'm sure; cautious after making a change until we've got used to the difference. I imagine it will indeed be a positive step forward though for you as you mention the effect is similar to those you've had before with other things.
Regards
Scott
Good news Peter! I know that's been a thorn in your side for a while, so I'm very glad you've got it sorted out now
Hi Scott!
It has not been much of an issue since it occurs when playing loud. It's not so often I can do that with kids, wife and neighbors around
It seems that treble is down a decibel or something. Could it be that reflections thru the cones are gone?
Cheers
Hi Scott!
It has not been much of an issue since it occurs when playing loud. It's not so often I can do that with kids, wife and neighbors around
It seems that treble is down a decibel or something. Could it be that reflections thru the cones are gone?
Cheers
Very likely that's a major part of it. Reflections back through the cone are a pain, as the also cause problems in the time domain. Plus, the HF is more easily absorbed with damping higher up the line, near the driver, so it should prevent some leakage along the horn. If you've got a layer of damping on the base of the cabinet, that should do the trick nicely, filtering off most of the unwanted higher frequencies, but preserving the LF we want.
Not really. Driver position (Zdriver) along the line is determined by the need to supress harmonic ripple as much as practicable while keeping the driver at a sensible height.
When you mount a driver at the selaed end of a line, it will activate all the resonant modes; the cabinet first mode (or fundamental resonance), and the higher harmonic resonances, equally. By moving the driver further along the line you can (mostly) preserve the fundamental, while reducing the excitation of certain harmonics.
When you mount a driver at the selaed end of a line, it will activate all the resonant modes; the cabinet first mode (or fundamental resonance), and the higher harmonic resonances, equally. By moving the driver further along the line you can (mostly) preserve the fundamental, while reducing the excitation of certain harmonics.
Time...
An interestion point. Remember, Terry Cain's original has a WxD ratio of 1:2.2 and there were no complains about sonics. My first experimental pair had a ratio of 1:3; again they sounded great. The ideal expansion will improve things of course, but how much is an interesting question -Martin's sheets can't give us the whole story at the moment, in this respect, though there are indications it does indeed reduce ripple somewhat, as you'd hope for / expect. Unless you're planning on building another box though, I wouldn't worry about it.
