Hello diy'ers!
First of all, thanks so much for the archives built up here. Truly this is an impressive community of enthusiasts.
I'm just starting to cut wood for my first project: Jordan jX92S's in the Jordan suggested transmission lines. I've been lurking around here for so long and pondering so many options that I'm super-excited to have my drivers and other materials on hand and to have actually cut wood!
While I can cut both straight and square, I'm not so good on metric conversion. My first goof is that I cut my front and back panels to 11 inches rather then the 11.8 inches for which the plans call. Working the spreadsheets is not something I've studied yet. Is this a fatal error? Will this .8-inch error mess up my volume in a way that will be noticeable audibly? I would guess that I'm better off making a new set, but I'd rather not waste the material if I don't have to.
While I'm typing, I'd like to fish for any general pointers. I intend to miter cut the outside of the boxes and use biscuits and a lot of glue to attach the panels. I'm going to use a thin foam seal within the rebate in which the driver will be seated. I'm going to seal as much possible the inside of the box with some kind of caulk. Yes? Any other things to consider? One thing I thought would be really cool would be to have a 'Basic Box Building' section on the wiki. Maybe it's there or somewhere else on this forum - am I missing it?
I'm also googling around for a good veneering primer, if there's something that you know of that you really like I'd appreciate the link.
Thanks,
Paul
First of all, thanks so much for the archives built up here. Truly this is an impressive community of enthusiasts.
I'm just starting to cut wood for my first project: Jordan jX92S's in the Jordan suggested transmission lines. I've been lurking around here for so long and pondering so many options that I'm super-excited to have my drivers and other materials on hand and to have actually cut wood!
While I can cut both straight and square, I'm not so good on metric conversion. My first goof is that I cut my front and back panels to 11 inches rather then the 11.8 inches for which the plans call. Working the spreadsheets is not something I've studied yet. Is this a fatal error? Will this .8-inch error mess up my volume in a way that will be noticeable audibly? I would guess that I'm better off making a new set, but I'd rather not waste the material if I don't have to.
While I'm typing, I'd like to fish for any general pointers. I intend to miter cut the outside of the boxes and use biscuits and a lot of glue to attach the panels. I'm going to use a thin foam seal within the rebate in which the driver will be seated. I'm going to seal as much possible the inside of the box with some kind of caulk. Yes? Any other things to consider? One thing I thought would be really cool would be to have a 'Basic Box Building' section on the wiki. Maybe it's there or somewhere else on this forum - am I missing it?
I'm also googling around for a good veneering primer, if there's something that you know of that you really like I'd appreciate the link.
Thanks,
Paul
Just caught up with this. The dimensions of the VTL are pretty tight so you may be better off cutting new front and rear panels. Alternatively, have you cut the internal panels yet? You could increase the depth of the cabinet to compensate and give yourself the same cross-sectional area for the three lines. (Alternatively, don't rebate the dividing panels and that might achieve the same area.)
My other suggestion would be to use thinner material for the dividing panels between the lines - half inch, say - as the panels aren't too wide and so vibration won't be too much of a problem. The cavity at the top can probably take the reduced dimensions.
The trouble with any fiddling like this is that although it MAY make no difference, if you go to the trouble of finishing it and then don't like something about the sound - is it the design or the compromises? So I would recut and put the other panels to one side for a future project.
Rebate the drivers and foam will be fine for sealing them. It's worth bevelling the rear edge of the mounting hole, to cut away any sharp edges near the driver and give an easier air flow. (Don't forget to protect the driver when mounting it, the cones dent easily.)
I can't comment on biscuits etc as that's beyond my woodworking. I use woodworking adhesive (lots of it) and pin things in place whilst the glue sets.
There are a few good veneering sites available here in the UK but I don't know about the States. There has been quite a bit of discussion in the past, both here and at the fullrange driver forum, so try a search.
And let us know how you get on with the project.
Colin
My other suggestion would be to use thinner material for the dividing panels between the lines - half inch, say - as the panels aren't too wide and so vibration won't be too much of a problem. The cavity at the top can probably take the reduced dimensions.
The trouble with any fiddling like this is that although it MAY make no difference, if you go to the trouble of finishing it and then don't like something about the sound - is it the design or the compromises? So I would recut and put the other panels to one side for a future project.
Rebate the drivers and foam will be fine for sealing them. It's worth bevelling the rear edge of the mounting hole, to cut away any sharp edges near the driver and give an easier air flow. (Don't forget to protect the driver when mounting it, the cones dent easily.)
I can't comment on biscuits etc as that's beyond my woodworking. I use woodworking adhesive (lots of it) and pin things in place whilst the glue sets.
There are a few good veneering sites available here in the UK but I don't know about the States. There has been quite a bit of discussion in the past, both here and at the fullrange driver forum, so try a search.
And let us know how you get on with the project.
Colin
Hi Paul,
I am currently exploring TLs. One thing I have found so far, is the length of the line has more effect than the volume of the line.
That is with a straight pipe line. Yours is folded? Will the error affect length and volume? Someone has most likely spent a lot of time on the design. I would suggest you put the offending panel aside and stick to the plans. You will end up with something to be enjoyed, not something to re-engineer.
Wood working is not my forte either. Though I am getting better. Don't worry too much about that short piece, you have been bitten. As Colin said, it will get used.
Good luck with the project.
Geoff
I am currently exploring TLs. One thing I have found so far, is the length of the line has more effect than the volume of the line.
That is with a straight pipe line. Yours is folded? Will the error affect length and volume? Someone has most likely spent a lot of time on the design. I would suggest you put the offending panel aside and stick to the plans. You will end up with something to be enjoyed, not something to re-engineer.
Wood working is not my forte either. Though I am getting better. Don't worry too much about that short piece, you have been bitten. As Colin said, it will get used.
Good luck with the project.
Geoff
Bite the bullet and make the panels the proper size. If you don't, you'll spend the rest of your time with the speakers constantly reflecting that you'd compromised. You'd also have to alter the positons of the internal panels that make the line, or the tuning will be off. Annoying I know, but it'll be worth it in the long run.
Line length is important in a TL (or in these cabinets' case, a Daline chambered QWR). Line length determines the tuning frequency. Cabinet volume however, ensures that there is suffient gain across the passband of operation. For example, you can have two lines, of identical length, identical driver position, identical driver, but one is half the volume of the other. The latter will not provide the same gain as the former, despite having a notionally identical cut-off.
Line length is important in a TL (or in these cabinets' case, a Daline chambered QWR). Line length determines the tuning frequency. Cabinet volume however, ensures that there is suffient gain across the passband of operation. For example, you can have two lines, of identical length, identical driver position, identical driver, but one is half the volume of the other. The latter will not provide the same gain as the former, despite having a notionally identical cut-off.
Butt joints using drywall screws every 8 inches or so (and of course glue). Use a counter-sink bit for pilot holes, then you can fill them in with tinted wood filler. That's how my speaker boxes were built:
http://i68.photobucket.com/albums/i6/heatherandsteve/Projects/0567e9db.jpg
Practice on some scrap, otherwise you'll be practicing on your project.
Convert from metric to English thrice, measure twice, cut once.
http://i68.photobucket.com/albums/i6/heatherandsteve/Projects/0567e9db.jpg
Practice on some scrap, otherwise you'll be practicing on your project.
Convert from metric to English thrice, measure twice, cut once.
Thanks for the thoughts - it certainly helps. I'll consider the margin of error for volume to be +/- 0%.
Upon reflection it was clear to me that those 34 x 11 boards would in fact be well-used if configured into four shelves in an unused corner of my growing workshop. I did re-cut and began building according to the plans, and after completing one box and learning a lot in the process, I intend to start over one more time and apply with care my newfound appreciation of "straight" and "square". Important things, those. Happily, the work is satisfying enough in and of itself that my penchant for impatience is being held in check, which is important. In addition to desiring excellent speakers, I'm working with tight aesthetic and placement constraints. I think I'll do a veneer on my practice box as well.
Upon reflection it was clear to me that those 34 x 11 boards would in fact be well-used if configured into four shelves in an unused corner of my growing workshop. I did re-cut and began building according to the plans, and after completing one box and learning a lot in the process, I intend to start over one more time and apply with care my newfound appreciation of "straight" and "square". Important things, those. Happily, the work is satisfying enough in and of itself that my penchant for impatience is being held in check, which is important. In addition to desiring excellent speakers, I'm working with tight aesthetic and placement constraints. I think I'll do a veneer on my practice box as well.
Your speakers look fantastic. I thought, though, that screws were taboo? I don't know that I've read that, but I did notice many people claiming that their boxes were built without the use of screws, so I came to think that metal hardware was to be avoided. Did I take away the wrong message? Was this instead a reference to their woodworking expertise? That's one of the tricky parts about learning through forum lurking, getting the right take-away lesson.Dumbass said:
Funny - I didn't start out with that plan but that's exactly where I ended up!
Sage advice.
Fine woodworkers like to use more elegant joints than I have the skill/patience/tools for.pwef said:
pwef said:
For some of us, using screws is how we get around having enough (or long enough) clamps to hold the pieces together while the glue dries. I use finish nails for the same purpose, since I own a couple of pneumatic nail guns and they leave small holes that are easily filled. Neither nails or screws will add anything to the strength of the finished joint, that's all up to the glue. Screws or nails may prevent you from rounding over the corners of the box, which is essential if you are using small diameter drivers on narrow baffles.
I also have a 'biscuit' joiner, but I don't count on the biscuits to hold the box together. I just use them to make it easy to keep the panels aligned and square when I glue them up.
Neither the nails nor the biscuits are exactly fine furniture building techniques, but I don't expect my speakers to be handed down for generations like valuable antiques. For now I'm happy if they go together and sound more or less as intended.
pwef said:
Have you considered the Peter Millet TL design using this unit ?
http://www.pmillett.com/jx92s.htm
Looks very impressive performance, and compact cabinet.
A fine design. However, I would suggest that the best cabinet of the lot are Greg Monfort's MLTLs. GM has two designs; a 31in and a 48in; both model superbly, and have an excellent reputation among builders.
Scottmoose said:
I would like to build the 48" TL some day, but make the vents rectangular (wood) and vent to the side.
I should have mentioned, my brother earns the lion's share of responsibility. I had the brilliant idea to build them with pine boards, so my brother had to cut, edge join, plane, etc, while I essentially watched and made sure his coffee was fresh. Pine is very hard to work with for this sort of project, cabinet-grade plywood is MUCH MUCH more rational a decision.pwef said:
But if you butt-joint, then you have to decide what to do with edges. I actually like the look of plywood edges, but they don't take stain very well (blotchy).
I will take responsibility for the finish of those pine cabinets. I filled the screw holes, sanded down the wood (by hand!), and finished with multiple layers of garnet shellac. I love shellac, but it is somewhat tricky to work with. Wait for a warm, dry day to do it. And make sure the room is well ventilated, breathing that denatured alcohol will make you see your ancestors.
Scottmoose said:
Thanks for bringing this up.
I did notice that there is no shortage of enthusiasm for these designs, whereas the Jordan TL is merely beloved. One of my critical parameters is non-fussy placement, and I saw ample testimony that the Jordan design excelled in that capacity. I was under the impression that the (comparatively) wide baffle of the Jordan design contributed to that. I did try to search out similar opinions on the GM design but found no one commenting on its placability (that I can recall). The front port and the triangular variation seemed to imply that these things aren't afraid of corners or back walls. For my needs and these reasons, and the fact that cosmetically I think the Jordan design has the edge (I can't tell you how many times I leafed through the gallery), I decided to go the Jordan TL route.
Now that the question is out there, I'm curious if anyone has an informed opinion on the placibility of the GM design vs. the Jordan TL design?
I had not seen this design before. My Google prowess is not as strong as it needs to be. I'll definitely study this. Thanks!
The Jordan VTL design and the MLTL has been discussed in a previous tread: First Impression: GM's Jordan JX92S MLTL Speaker
See page 2 (post#11) and #3 (post #22) for simulations of the VTL and the MLTS.
The VTL appears to have a gentle roll-off below about 80 Hz, while the MLTL is "ruler-flat" to 40 Hz. This difference might explain the easy placement of the VTL.
SveinB.
See page 2 (post#11) and #3 (post #22) for simulations of the VTL and the MLTS.
The VTL appears to have a gentle roll-off below about 80 Hz, while the MLTL is "ruler-flat" to 40 Hz. This difference might explain the easy placement of the VTL.
SveinB.
The Jordan design (VTL) is the one I have heard, and has been widely touted. There are at least a couple commercial versions of it.pwef said:
I agree about the looks and the advantages of the wide baffle.
I've seen modeled plots of the VTL vs GM's designs. No surprise (since GM used the same software to design them), his go somewhat lower, especially the 48". IIRC the VTL had a gradual drop-off in the low freqs, which IMO is good.
pwef said:
I seem to lack an "edit" button and I wish to correct a couple errors in my post #15.
Where I have written "Jordan TL" please read "VTL".
Not only did I make up the word "placability", but I spelled it differently each time I used it. I was referring to the speaker's ease of placement in a room, which is characteristic that I desire from this build.
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