Hi Studio Au,
Good idea!
Is the internal width of the enclosure too wide? Or did you keep the same vent area while reducing its width? Just checking. Also agreeing with JoeyGS's comment.
I would err on having more structural rigidity for the moving driver. Remember those gaps between the tabs are going to be blocked anyway by the gasket and driver frame. A small 5mm chamfer would suffice for airflow behind the driver without impinging on the fixing points - the CNC routing should be more than careful enough.
IMHO, Baltic birch is the best loudspeaker material - Corian is a dead material for dead sound (and the cutting costs could be massive - particularly with quickly blunting the bits)
One of my main principles is reducing the fore-aft reactive movement of the cabinet in response to the driver. The brace reduces panel movement from air compression - but I try to reduce panel movement from air expansion by routing channels 9mm in from the front back edges of the top and back edge of the base - rebates routed in the front and back will allow those panels to slot into the top and bottom and structurally resist outward air pressure. It does however preclude the removable feature of the back panel, stuffing would need to be adjusted by clamping on/off the side before gluing. So, overall from a product standpoint you may prefer your approach.
No - use D-Nuts not T-Nuts. It's either the M8 or M6 ones that are shallow enough to only need drill about 2/3 of the way into 18mm material. Maybe similar to the Hafele inserts you mention. Search for D-Nuts on ebay to see what I mean.
I hope this feedback helps to optimise your final product.
Cheers,
Andrew
Good idea!
Is the internal width of the enclosure too wide? Or did you keep the same vent area while reducing its width? Just checking. Also agreeing with JoeyGS's comment.
I would err on having more structural rigidity for the moving driver. Remember those gaps between the tabs are going to be blocked anyway by the gasket and driver frame. A small 5mm chamfer would suffice for airflow behind the driver without impinging on the fixing points - the CNC routing should be more than careful enough.
IMHO, Baltic birch is the best loudspeaker material - Corian is a dead material for dead sound (and the cutting costs could be massive - particularly with quickly blunting the bits)
Understood that a removable back is required to optimise the stuffing. Personally I'd optimise (holding in place with clamps) and then glue it.
One of my main principles is reducing the fore-aft reactive movement of the cabinet in response to the driver. The brace reduces panel movement from air compression - but I try to reduce panel movement from air expansion by routing channels 9mm in from the front back edges of the top and back edge of the base - rebates routed in the front and back will allow those panels to slot into the top and bottom and structurally resist outward air pressure. It does however preclude the removable feature of the back panel, stuffing would need to be adjusted by clamping on/off the side before gluing. So, overall from a product standpoint you may prefer your approach.
No - use D-Nuts not T-Nuts. It's either the M8 or M6 ones that are shallow enough to only need drill about 2/3 of the way into 18mm material. Maybe similar to the Hafele inserts you mention. Search for D-Nuts on ebay to see what I mean.
I hope this feedback helps to optimise your final product.
Cheers,
Andrew
Rampa threaded inserts from Germany
https://www.rampa.com/cgi-bin/rampa...laeche=&laenge=&gewinde=&durchmesser=&sextid=
Look at the stock socket head screws supplied by Mark - for even the largest driver in current line - A12 series, I find 6 of the M4 thread SK (010 410 001) more than sufficient.
https://www.rampa.com/cgi-bin/rampa...laeche=&laenge=&gewinde=&durchmesser=&sextid=
An externally hosted image should be here but it was not working when we last tested it.
Look at the stock socket head screws supplied by Mark - for even the largest driver in current line - A12 series, I find 6 of the M4 thread SK (010 410 001) more than sufficient.
An externally hosted image should be here but it was not working when we last tested it.
Mentioned already.
Vent should be right at the bottom... created by making the baffle short enuff to form the vent.
dave
Thanks for all the feedback.
We'll lower the port on the next one. Cabinet is wider than normal to allow for the bracings displacement. but the port is the size depicted on the drawing. Just in the wrong place somehow!
Annoyingly the engineer put in the driver dimensions with the cover ring, so the rebate is about 2mm too low as well. I will alter it to allow for the .6mm veneer, so it will either be perfectly flush when veneered or a fraction proud if bare ply. Ill shim this one up and get it painted to hide the ugly ply.
Has anyone tried over veneering baffles, with the driver cutouts already done? Can imagine its that easy? I guess a flush cutting bit would make light work of it.
We'll lower the port on the next one. Cabinet is wider than normal to allow for the bracings displacement. but the port is the size depicted on the drawing. Just in the wrong place somehow!
Annoyingly the engineer put in the driver dimensions with the cover ring, so the rebate is about 2mm too low as well. I will alter it to allow for the .6mm veneer, so it will either be perfectly flush when veneered or a fraction proud if bare ply. Ill shim this one up and get it painted to hide the ugly ply.
Has anyone tried over veneering baffles, with the driver cutouts already done? Can imagine its that easy? I guess a flush cutting bit would make light work of it.
Louis - I "post-veneer" all of my builds, and using the iron-on method, find trimming of the driver cut-outs quite simple, actually.
Between the combination of scorching of the driver, terminal cup and vent cut-outs ( don't worry, they'll sand out easily ) , a sharp utility or veneer knife, and some practice at using the nose of the iron to shear the paper backed veneer, you can get it done quite nicely.
Between the combination of scorching of the driver, terminal cup and vent cut-outs ( don't worry, they'll sand out easily ) , a sharp utility or veneer knife, and some practice at using the nose of the iron to shear the paper backed veneer, you can get it done quite nicely.
Did my mail get to AU Audio
Hey AU Audio,
I really like the sound of the CNC kit for the Pensil 7.3, especially as Baltic Birch is impossible to source here in Brazil.
I tried leaving a message for you on your website, but have no idea if you got it (website gave no indication).
Please, drop me a line here (PM or something) and we can talk further!
Cheers!
Hey AU Audio,
I really like the sound of the CNC kit for the Pensil 7.3, especially as Baltic Birch is impossible to source here in Brazil.
I tried leaving a message for you on your website, but have no idea if you got it (website gave no indication).
Please, drop me a line here (PM or something) and we can talk further!
Cheers!
Transoceanic shipping of flat pack kits for all but the smallest enclosures - which the Pensil7.3 or the Planet10 FH3, would get stupidly expensive, very quickly.
Which is the point of folks like Mark, Scott and Dave encouraging local
"cottage industry" production of these designs.
"Baltic" birch is as much a generic name for a particular type of high count plywood as a brand name, and with some research you might find a suitable similar product available closer to home?
Which is the point of folks like Mark, Scott and Dave encouraging local
"cottage industry" production of these designs.
"Baltic" birch is as much a generic name for a particular type of high count plywood as a brand name, and with some research you might find a suitable similar product available closer to home?
Chris, Thanks for you reply. I wholeheartedly agree that it will probably be stupidly expensive, but no, it does not seem there are great alternatives here.
There are some types of reasonable quality plywoods here (as used in boat-building for example), but these seem very difficult to source in small quantities and I would then either need to buy a table saw (not easy to source reasonably priced power-tools here due to heavy import tax) and some clamps (and, and...), OR find both a CNC cutting service and obtain a CNC plan for the Pensil 7.3. I will certainly pursue one of those options if it proves either ridiculously expensive, or a bureaucratic nightmare to import from elsewhere.
All suggestions gratefully received, especially from anyone with experience of such issues here in Brazil.
(Loving this site by the way. I have learned a lot already!)
There are some types of reasonable quality plywoods here (as used in boat-building for example), but these seem very difficult to source in small quantities and I would then either need to buy a table saw (not easy to source reasonably priced power-tools here due to heavy import tax) and some clamps (and, and...), OR find both a CNC cutting service and obtain a CNC plan for the Pensil 7.3. I will certainly pursue one of those options if it proves either ridiculously expensive, or a bureaucratic nightmare to import from elsewhere.
All suggestions gratefully received, especially from anyone with experience of such issues here in Brazil.
(Loving this site by the way. I have learned a lot already!)
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The raw conceptual plans for the Pensil and FH designs are freely available, with the proviso that for personal use only - commercial production requires a licensing fee to Martin King.
"CNC plans" depend to a degree on the chosen joinery methods (dadoes, biscuits, lock miters, etc.,) and bracing. The latter is highly recommended, and the techniques used by builders have ranged from a few simple crossing dowels, to the elaborate full length arrangements shown in Louis' photos above, or as in my own build below, before stuffing with fiber fill.
"Marine"/ boat building grade ply may very well be equivalent to a shop grade of BB ply - products locally available would certainly merit research. If there is any fine furniture / bespoke kitchen cabinet manufacturing, they may also have access to the materials, as well as CNC machines.
"CNC plans" depend to a degree on the chosen joinery methods (dadoes, biscuits, lock miters, etc.,) and bracing. The latter is highly recommended, and the techniques used by builders have ranged from a few simple crossing dowels, to the elaborate full length arrangements shown in Louis' photos above, or as in my own build below, before stuffing with fiber fill.
"Marine"/ boat building grade ply may very well be equivalent to a shop grade of BB ply - products locally available would certainly merit research. If there is any fine furniture / bespoke kitchen cabinet manufacturing, they may also have access to the materials, as well as CNC machines.
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Like here, there must be "well off" people in Brazil building boats and fancy kitchens. It's just a function of seeking them out, or the designers.
jeff
Thanks Chris. Yes, I already have the MarkAudio plans, and am already trying to see what CNC design and cutting services might help here + now talking to Studio AU (thanks for the quick reply!).
Vinylkid 58. Yes, there are rich people here, and they do use plywood products. The problem seems to be that even these services do not use anything like real baltic birch in terms of either number of ply/unit of thickness or overall quality (+ the woods they use seem to not be acoustically very good). Also, much of the 'maritime' stuff here is treated with some pretty nasty stuff. Kitchens: there's still a lot of good hard/medium-hard wood around in Brazil (if you can afford it) + lots of nice granite, so ply is not used much and generally hidden where nobody cares what it looks like.
Vinylkid 58. Yes, there are rich people here, and they do use plywood products. The problem seems to be that even these services do not use anything like real baltic birch in terms of either number of ply/unit of thickness or overall quality (+ the woods they use seem to not be acoustically very good). Also, much of the 'maritime' stuff here is treated with some pretty nasty stuff. Kitchens: there's still a lot of good hard/medium-hard wood around in Brazil (if you can afford it) + lots of nice granite, so ply is not used much and generally hidden where nobody cares what it looks like.
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