Andy,
Ideally yes the speaker frame should be recessed flush into the front baffle but unless you have access to a CNC router forget it. Just screw the driver on to the front baffle making sure you have clearence around the hole, which should be chamfered on the inside. That's how my Fonken167 are built and I doubt very much you would detect any difference in sound if it was recessed in.
As you live near me (Lancashire) you are welcome to come over and listen to the Fonken167 anytime.
Ideally yes the speaker frame should be recessed flush into the front baffle but unless you have access to a CNC router forget it. Just screw the driver on to the front baffle making sure you have clearence around the hole, which should be chamfered on the inside. That's how my Fonken167 are built and I doubt very much you would detect any difference in sound if it was recessed in.
As you live near me (Lancashire) you are welcome to come over and listen to the Fonken167 anytime.
I posed a similar question a while back and the answer was that flush mount only matters on 6 in drivers or better (from GM I think.)
But the process for flush mounting irregular shapes can be done with a conventional router. The process was described in an article in Speakerbuilder some time ago and there is a thread here-- a how to thread-- which describes what that author wrote. Unfortunately the article with pictures is not available from a non print source.
I will find the thread and close by saying that doing flush mount of irregular shapes follows the steps used to make duplicate sub base plates for routers which is a common practice. A pattern is made and then transferred to the baffle and the router accurately traces the pattern. There's a few steps in between. Just now I am learning to make the sub bases for both a router and a smaller zip tool (laminate trimmer with base accessories.)
http://www.diyaudio.com/forums/everything-else/122788-flush-mounting-speakers-whole-story.html
Alternatively GM has suggested that a thin baffle layer with a hole cut in it in the right shape applied over the driver will give the flush mount effect.
But the process for flush mounting irregular shapes can be done with a conventional router. The process was described in an article in Speakerbuilder some time ago and there is a thread here-- a how to thread-- which describes what that author wrote. Unfortunately the article with pictures is not available from a non print source.
I will find the thread and close by saying that doing flush mount of irregular shapes follows the steps used to make duplicate sub base plates for routers which is a common practice. A pattern is made and then transferred to the baffle and the router accurately traces the pattern. There's a few steps in between. Just now I am learning to make the sub bases for both a router and a smaller zip tool (laminate trimmer with base accessories.)
http://www.diyaudio.com/forums/everything-else/122788-flush-mounting-speakers-whole-story.html
Alternatively GM has suggested that a thin baffle layer with a hole cut in it in the right shape applied over the driver will give the flush mount effect.
Routing a rebate for the driver is the preferred method, but with the Fostex, it is largely cosmetic.
To accomplish this, a router template can be made (i'll leave that to the wood-workers to describe), it can be freehanded (usually never perfect and easier if you have a small router), or with the use of a CNC machine (fortunately something we have access to)
The depth of the holey brace changes depending on how you mount the driver.
dave
To accomplish this, a router template can be made (i'll leave that to the wood-workers to describe), it can be freehanded (usually never perfect and easier if you have a small router), or with the use of a CNC machine (fortunately something we have access to)
The depth of the holey brace changes depending on how you mount the driver.
dave
food for thought then...
Thanks for replies so far chaps.
For myself I am a dab-hand with AutoCad. The major advantage of this superb program is that not only is it dead simple to use, but 1:1 plots can be made to a printer for checking.
I have access to a workshop chock to overflowing with woodworking tools and I have quite a bit of amature experience in woodworking but I will say this: Of all the tools I have ever used in anger, routers give me the heebeejeebies (and I don't mind admitting that) - they are an utter pain in the ().() to use. There's just something nasty and awkward about the damn things and they are a PIG to set up. I do NOT like using them by hand (I always use them bolted to a router bench).
First: I will think of using AutoCad to very accurately draw the outside profide of the speaker. I will then use the offset function (offset distance based on either the collar diameter of the router or the bit I intend to use) to create a jig and try that method.
I think the idea of glueing a laminate layer to provide the recess is an excellent one - I'm just trying to figure how to actually do that: To maintain the dimensions I'd have to:
1) Skim 3mm off the thickness of the front piece of wood.
2) Cut the irregular shape in a second piece of wood (same dimensions)
3) Skim the 12mm thick piece of from step 2) down to 3mm thick (ouch!)
4) Glue the two together.
Fortunately I have access to a planer, but even so...!
-----
If I crack a reasonably easy(est) method of doing this I will post up some pics etc if I get time.... Engineer hat on then.
Andy
Thanks for replies so far chaps.
For myself I am a dab-hand with AutoCad. The major advantage of this superb program is that not only is it dead simple to use, but 1:1 plots can be made to a printer for checking.
I have access to a workshop chock to overflowing with woodworking tools and I have quite a bit of amature experience in woodworking but I will say this: Of all the tools I have ever used in anger, routers give me the heebeejeebies (and I don't mind admitting that) - they are an utter pain in the ().() to use. There's just something nasty and awkward about the damn things and they are a PIG to set up. I do NOT like using them by hand (I always use them bolted to a router bench).
First: I will think of using AutoCad to very accurately draw the outside profide of the speaker. I will then use the offset function (offset distance based on either the collar diameter of the router or the bit I intend to use) to create a jig and try that method.
I think the idea of glueing a laminate layer to provide the recess is an excellent one - I'm just trying to figure how to actually do that: To maintain the dimensions I'd have to:
1) Skim 3mm off the thickness of the front piece of wood.
2) Cut the irregular shape in a second piece of wood (same dimensions)
3) Skim the 12mm thick piece of from step 2) down to 3mm thick (ouch!)
4) Glue the two together.
Fortunately I have access to a planer, but even so...!
-----
If I crack a reasonably easy(est) method of doing this I will post up some pics etc if I get time.... Engineer hat on then.
Andy
I might point out as has already been said, the Fostex stamped frame drivers are intended to be surface mounted. I doubt that they will look right if rabbeted into the baffle because of the radius on the edge of the frame. You will have a sharp edge on the cutout followed by a depression formed by the round-over on the edge of the frame. Also note the plastic defraction ring just outside of the surround. That will negate any advantage from rabbeting the baffle.
The cast frame Fostex drivers, the sigma series and the F200A, are another story. The thick cast frame does not look right surface mounted and demands rabbeting in.
Bob
The cast frame Fostex drivers, the sigma series and the F200A, are another story. The thick cast frame does not look right surface mounted and demands rabbeting in.
Bob
Bob,
if you use the guide bushings with a bit that matches the radius of the frame edge in like manner to mounting the router baseplate in the table, there should be no ugly square edges at the "turns" around the corners. I know it seems like going a mile to gain an inch.
underwurlde,
Caution around tools is fully warranted. I used a small zip tool with accessories for years before getting an actual router.
The well-worn cautionary joke is from those who would say it is easy:
eg: "I've been doing woodworking for 30 years and I still have all eight fingers."
if you use the guide bushings with a bit that matches the radius of the frame edge in like manner to mounting the router baseplate in the table, there should be no ugly square edges at the "turns" around the corners. I know it seems like going a mile to gain an inch.
underwurlde,
Caution around tools is fully warranted. I used a small zip tool with accessories for years before getting an actual router.
The well-worn cautionary joke is from those who would say it is easy:
eg: "I've been doing woodworking for 30 years and I still have all eight fingers."
Bob,
They look fine. To my eye better than we do a quick surface mount. I have lots of examples.
dave
<off-topic>
One of my other jobs is computer support. A lot of my clients are architects.
IMO, capable as it may be, AutoCad is clumsy & a bit of a dinosaur and vastly overpriced (and AutoDesk has a certain arrogance i find distasteful). Like M$ Word & Excel, just another case of most people never having the opportunity to use something that shows how bad they are.
</off-topic>
dave
^ yeah kind of with you there: it is getting old school now but I think of it as an essential tool in the tool box along with a ruler & a calculator. Yes it is clumsy (all that typing) but its what I'm used to I guess so I hit the ground running with it.
Been trying to convince my employers to train me up in the use of solid works. Now THAT looks powerful. All our products are now designed using that package but being an electronics engineer (and not one of the meccies) I'm being asked why, exactly, do I want training up on it.....
-----------
I have come up with a cunning plan. I have very accurately matched the outline of the FF85K speaker driver in AutoCad: Fortunately it's outer edge does not appear to be elliptical and I think it closely matches an arc with a radius of 112mm. The corners I reckon are 7mm diameter fillets.
Hence if I attach a router to a bit of wood such that the router acts like a compass I can possibly create the profile I need.... Fit a 7mm router bit and set the radius to 112mm-(7mm/2).
Another bit of wood onto which the above 'bit of wood' + router pivots will have a rectanglular hole cut in it that matches the shape of the front baffle to be routed... plop the front baffle to be cut it in & route away...
Viola? We'll see....
Andy
Been trying to convince my employers to train me up in the use of solid works. Now THAT looks powerful. All our products are now designed using that package but being an electronics engineer (and not one of the meccies) I'm being asked why, exactly, do I want training up on it.....
-----------
I have come up with a cunning plan. I have very accurately matched the outline of the FF85K speaker driver in AutoCad: Fortunately it's outer edge does not appear to be elliptical and I think it closely matches an arc with a radius of 112mm. The corners I reckon are 7mm diameter fillets.
Hence if I attach a router to a bit of wood such that the router acts like a compass I can possibly create the profile I need.... Fit a 7mm router bit and set the radius to 112mm-(7mm/2).
Another bit of wood onto which the above 'bit of wood' + router pivots will have a rectanglular hole cut in it that matches the shape of the front baffle to be routed... plop the front baffle to be cut it in & route away...
Viola? We'll see....
Andy
SolidWorks will be interesting when they put a proper Mac OS X UI on it and use the power of Quartz.
My uses don't require that kind of functionality. My drawing style is still much governed by my original paper & pencil drafting studies (but using a lot & extended by the functionionality built into my CAD SW)
I've been using VectorWorks for 20+ years. Using the "identical" Windows version sure shows up how poorly thot out the Windows UI is.
It dominates the local architectural market -- you can buy a loaded 24" iMac + VectorWorks for less than a seat of AutoCad.
dave
My uses don't require that kind of functionality. My drawing style is still much governed by my original paper & pencil drafting studies (but using a lot & extended by the functionionality built into my CAD SW)
I've been using VectorWorks for 20+ years. Using the "identical" Windows version sure shows up how poorly thot out the Windows UI is.
It dominates the local architectural market -- you can buy a loaded 24" iMac + VectorWorks for less than a seat of AutoCad.
dave
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