Dayton CX150-8 Coaxial Project

[1100xxben]

Here in California where humidity is typically below 40%, wood glue dries fast, I'd say a few hours would be enough, maybe 6, but I was shocked at how long Titebond took to dry in Ohio this summer at MWAF, overnight it was still nowhere near dry. I'd say 24hrs to be safe if it's humid, or maybe haul the setup into a dehumidified AC part of the house if you have it.

You were also here when we had about 101% humidity too . Of course, that's not atypical for the summer months!

[JavadS]

You were also here when we had about 101% humidity too . Of course, that's not atypical for the summer months!

Man it was brutal! =)

[emilime75]

Nice work on testing the driver and the effects of the vented former. It appears as you'll likely not have a problem. However, aside from the potential chuffing, an air leak in a speaker enclosure also effects response, something that I'm not sure can be accounted for, or modeled. I still don't think it'll have much, if any, impact on your use of the driver with a 400Hz crossover, but it will others who'd like to use it as a "fullrange", as it's advertised.

[4thtry]

I'm using Titebond II in my basement. Air conditioning, as needed, upstairs, helps a little to drop the relative humidity (RH) in the basement as well. A dehumidifier cycles on and off continuously in my basement to keep all my tools dry. Basement temp is currently a fairly constant 69 degrees with an RH (on my un-calibrated RH meter) of around 65 to 70%. If I did not run the dehumidifier, the RH would creep up to near 80% in the summer months. It drops to about 60% in the winter months. 12 hours seems to be about the minimum dry time. For this project, I have been leaving the clamps on for 24 hours, just for good measure.

[4thtry]

I now have 6 curved 1/8” layers glued together (total thickness of 3/4”). Overhang is about 1.75 inches on the ends and 1/2" along each side. I knuckle rap tested 3 layers verses 6 layers and found a slight improvement with 6 layers, but not much. I was going to stop at 3 layers, but since I had the wood already cut and my fixture was working good, I went ahead and glued up all 6 layers

[4thtry]

As I tightened the clamps, my fixture squeezed the panels down evenly, causing a nice, even dripping of glue along the entire side edge of the panel. However, glue did not squeeze out the panel ends as well as the sides. See my fix for this in the next post below:

[4thtry]

A weakness of my clamping fixture was low pressure at the top & bottom end points of the fixture. The fixture needed to be 2 or 3 inches longer than the wood being clamped to maintain constant pressure along the entire length. It was therefore necessary to insert blocks at each end of the fixture in order to get the glue to squeeze out properly along the ends. See pics below:

[tomzarbo]

Looking good!

I'm glad you used a lot of glue, too little can make a real mess. I've done that ONCE... but never again. Glue is pretty cheap compared to having one of the joints not hold as well as it should.

I have some trim-scraps laying around of a particularly curvy portion of HDF glue-up and it's extremely rigid -- almost like hardwood -- it's so strong. Those things are going to be solid! Nice fix on the ends as well. I don't see how you could have known that that would happen until you added glue... one instance where a "Dry" fitting won't cut it.

I'm in the basement building speakers as well... Covered with a fine layer of sawdust, and wood glue in my finger nails...it's a good Saturday for both of us!

TomZ

[4thtry]

Looking good!

I'm glad you used a lot of glue, too little can make a real mess. I've done that ONCE... but never again. Glue is pretty cheap compared to having one of the joints not hold as well as it should.

I have some trim-scraps laying around of a particularly curvy portion of HDF glue-up and it's extremely rigid -- almost like hardwood -- it's so strong. Those things are going to be solid! Nice fix on the ends as well. I don't see how you could have known that that would happen until you added glue... one instance where a "Dry" fitting won't cut it.

I'm in the basement building speakers as well... Covered with a fine layer of sawdust, and wood glue in my finger nails...it's a good Saturday for both of us!

TomZ

Yea, I really slopped it on thick. Poured it out directly from the gallon jug, then used a 6" sweeggee to flatten it out. The 12 curved panels alone took over ½ gallon of glue! (See pic) (This gallon was full when I started). That is a lot of glue!!! You are correct, the end corrections were a fix after applying the glue. But the fix worked good and the end joints came out extremely rigid.

[4thtry]

Nice work on testing the driver and the effects of the vented former. It appears as you'll likely not have a problem. However, aside from the potential chuffing, an air leak in a speaker enclosure also effects response, something that I'm not sure can be accounted for, or modeled. I still don't think it'll have much, if any, impact on your use of the driver with a 400Hz crossover, but it will others who'd like to use it as a "fullrange", as it's advertised.

Thanks. I plan to run up a full set of FRD and ZMA files with the speakers mounted in the finished cabinets, without crossovers. These files will include cabinet diffraction as well as the complete response and impedance characteristic of each driver, down to about 300 or 400Hz. I doubt that the effect of the chuffing, if any, will show up on my curves. The slight leakage, however, may cause the in box Qtc to drop just a little bit.

[biscuitbarrell]

Here's a tip for those needing to print something large and only have access to standard 8-1/2x11 printers: Matthias Wandel at woodgears.ca (a very fun woodworking site) offers a free version of his BigPrint program for your PC. It allows you to print just about anything you could possibly need onto several sheets of standard printer paper, with a background grid of diagonal lines to act as registration marks. You just overlap the prints until all your lines and diagonals line up, and tape the sheets of paper together. The free version will print the word "eval" (as in "evaluation") on each sheet, which is non-intrusive, and is otherwise exactly the same as the version he offers for sale (cheap!). Check it out here: http://woodgears.ca/bigprint/index.html
Could be helpful!

[PWR RYD]

Great tip, thanks for the heads up!

[Wolf]

There used to be a program Shawn used called Rasterbator (spelling?) that was free and did exactly the same thing. I don't know if it's still out there or not.
Wolf

[Millstonemike]

Here's a tip for those needing to print something large and only have access to standard 8-1/2x11 printers: Matthias Wandel at woodgears.ca (a very fun woodworking site) offers a free version of his BigPrint program for your PC. It allows you to print just about anything you could possibly need onto several sheets of standard printer paper, with a background grid of diagonal lines to act as registration marks. You just overlap the prints until all your lines and diagonals line up, and tape the sheets of paper together. The free version will print the word "eval" (as in "evaluation") on each sheet, which is non-intrusive, and is otherwise exactly the same as the version he offers for sale (cheap!). Check it out here: http://woodgears.ca/bigprint/index.html
Could be helpful!

Also, Staples will print large format (up to 4' wide?) in any length for a very reasonable price. Ignore the online prices. Go in store for the price per ft² and hold them to price by the print size, not the paper width they use. You can also trim the printout in store to suit your needs with their large format paper cutter - a cutting wheel not school a cleaver type.

[PWR RYD]

Also, Staples will print large format (up to 4' wide?) in any length for a very reasonable price. Ignore the online prices. Go in store for the price per ft² and hold them to price by the print size, not the paper width they use. You can also trim the printout in store to suit your needs with their large format paper cutter - a cutting wheel not school a cleaver type.

Even better, thanks!