Yup, it definitely matters - it's indeed one of the joys of working with small full range drivers - a couple of thoughts:
If they have thin stamped metal basket frames and you intend to surface mount them on the front baffle, then chamfer the back side of driver cutout with a 45` router bit as deeply as you can.
You could also make upper portion of front baffle removable (we've done exactly that to allow for swapping out different driver models) and rear mount them with a similar bevel or radius on the front side, forming somewhat of a very shallow waveguide.
If you try the latter, you will need to clamp a scrap work piece with same size hole as the through hole under your driver plate to allow the router bearing a guide surface.
Thanks Chris that's really helpful and much appreciated. For the chamfer option I don't have a router (although I'll need to get one if this hobby takes off) and the mounting screws will need to bite on something in the corners so I was thinking of making 45 degree cuts into the wood at the back and (carefully) chiseling 4 sections of chamfer at the sides and top of the hole leaving about an inch in each corner which will be sort of where the basket legs are.
For the latter option do I cut off the top portion of the baffle and replace it with a much thinner piece of ply? Any ideas of how to attach that piece securely but invisibly whilst being able to remove it?
I think your last sentence relates to the former option?
For the latter option do I cut off the top portion of the baffle and replace it with a much thinner piece of ply? Any ideas of how to attach that piece securely but invisibly whilst being able to remove it?
I think your last sentence relates to the former option?
Hi Chris, I found this: http://www.diyaudio.com/forums/full-range/172937-frugel-horn-mk3-builds-build-questions-66.html at post 656 from someone who is obviously very knowledgeable on the subject 🙂 That's what I was thinking of doing do so I think I could get away with chiseling and/or rasping some decent scallops. Not a great material for a chisel but if it's sharp enough and I'm careful enough...
MY recommendation would be for a rasp rather than a chisel. In my experience it's much easier to achieve what you want with a rasp than chisel.
That Chrisb is! 🙂 And he usually takes the time to write moderately long and informative posts explaining this kind of stuff.
+1 fastbike1 on recommending the rasp - definitely will be easier with a rasp.
Cheers fellas, yes, I think that's the way to go. Chris, I understand the bit about the removable baffle now, I was a little bit slow this morning! That picture was really helpful.
So what would the good folk here recommend the best finish, or paint for MDF (re pic in post #1178), I'll probably end up using a roller rather than spraying (too much homebrew around!!)...
Thanks guys!
Thanks guys!
Since it's too late to reinforce the suggestion for multi-ply plywood (Baltic Birch, etc) 🙂, I'd suggest roller for quick painting of MDF. With some practice on scraps, you can use the rollers' texture as a feature.
High quality sprayed paint finish on MDF can be very time consuming*, requiring thorough sanding of any glue squeeze-out, sealing of raw edges, priming and generally several coats of color and or clear top coats.
OTOH, if surfaces aren't too badly scuffed from handing or assembly (clamp marks, etc) MDF can actually look rather nice after a light random orbit sanding to 220G and clear top coat of sprayed lacquer.
*as I've mentioned more than a couple of times, on a cabinet composed of all flat panels, by the time you calculate the materials and labor required for a "furniture grade" paint finish on MDF, a sheet veneer and clear oiled or sprayed lacquer finish can take far less time and cost less. But then again, I work in a commercial woodworking shop with access to wholesale pricing on materials, plenty of workspace, almost enough clamps, as well as a finishing area with decent spray equipment. Not everyone does.
Hammerite would be an interesting finish, there are some tips here MDF + Hammerite? | AVForums.com - UK Online and elsewhere if you search Hammerite and MDF.
This fella has done something different: Frugal Frogs (Frugal Horns Mk3) - a little fun speaker build... but on that thread there's also some useful painting tips on getting a high gloss finish. If I was going that I'd have probably bought a section of 3mm thick gloss black perspex and covered the front baffle with that.
This fella has done something different: Frugal Frogs (Frugal Horns Mk3) - a little fun speaker build... but on that thread there's also some useful painting tips on getting a high gloss finish. If I was going that I'd have probably bought a section of 3mm thick gloss black perspex and covered the front baffle with that.
I've used Hammerite before - rather tricky to get uniform texture on a panel surface as large as the FH3 with aerosol spray - and you'll go through quite a few cans by the time you get the several coats required. This is definitely one of the products that you need to apply numerous light coats, and follow the recommended between coat drying times or it'll not properly cure.
excerpt from that thread
Labor/time and material intensive - by my quick count of steps listed, that's a total of 10 spray coats with sanding after each, and IINM only the front panel of the FrugalFrogs got the high gloss black lacquer treatment - the side panels were covered in wallpaper. One could easily veneer and apply a couple of coats of oil or spray lacquer finish over in a single day.alternativeroute
I glued 3mm MDF to the front (to get a smooth surface). I then sealed it with a 50/50 mix of glue and water. Sanded it flat afterwards. I then sprayed on a Thick coat of MS filler. More sanding. I then sprayed 5 coats of NC lacquer gloss black. Some wet sanding (800, 1200, 1600 and 2000 grit wet paper). A final three layers of NC lacquer clear. Some wet sanding (only 1600 and 200 grit waterpaper) and then polishing with a polishing buff. It took about a week... If I was a little more patient I would of put on some more clear coat but by then I was gat of spraying (and wanted to do some listening)...
would that be opaque enough to hide the adhesive?
FH3 bipole?
Scottmoose, do you think the FH3 could be developed into a bipole to fill larger spaces, Its a fantastic design but could it be modified successfully for X2 FE126en??
Scottmoose, do you think the FH3 could be developed into a bipole to fill larger spaces, Its a fantastic design but could it be modified successfully for X2 FE126en??
Not with a pair of FE126En I'm afraid. It would need a new design, and a substantial increase in size. Sorry.
Thanks, I will take a look at your Woden designs, that's probably then way to go
FWIW, I've heard 2 of Scott's large dual (rear) mouth manifold designs for Fostex drivers ( FE126En & FE166En) - and have also built several bipole designs. For my money the Valiant and Victor achieve the benefits of a bipole without doubling the expense of drivers, while also avoiding the minimum listening distance of 3 meters or so for the full integration of the virtual MTM sources of front mouth designs.
note: the 60" or even taller enclosures may not pass the WAF test for everyone
He, he 😀 - bit of an understatement?
Btw, the FH3 has managed to garner kinder comments from a few ladies within family/friends (those who have been kind enough to pass comment).
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You could stack them, inverting the top pair. It would take some creative cabinetry and it wouldn't be bipole but would give you 2 per side.
Just finished building a pair of Frugal Horns.
Mark Audio CHR-70
Hours and hours of work to get the piano gloss finish right but I'm pretty damn happy with them.
Not running them through any special amp at the moment but the sound is incredible. I was super impressed with the bass response for such a small speaker. Wow!
Mark Audio CHR-70
Hours and hours of work to get the piano gloss finish right but I'm pretty damn happy with them.
Not running them through any special amp at the moment but the sound is incredible. I was super impressed with the bass response for such a small speaker. Wow!
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An externally hosted image should be here but it was not working when we last tested it.
Super job markmaxwell, that piano gloss finish is impressive! Go ahead and post on the FR speaker gallery too.
Gen-1 of Gen-2 drivers you got there?
Gen-1 of Gen-2 drivers you got there?