Thanks CMOS. My next design will be as you suggest. GK with 2 tubes deep with no dampers. What has been your best method of attaching tubes to the 2 ports? Also what tubing if I might ask? I just tried a combination of a little super glue followed by UV gel on the GK sound port and ruined one of the tweeters (bought an extra though). I don't understand how the ports are not designed for a specific tubing. I've never felt good about any of the connections I've made on Knowles drivers.
I am most satisfied with the connection I get using UV gel. put a small amount of UV gel on the end of the tube, slip it over the sound port, and cure under a UV light. Once the tube is attached, apply a 2nd layer if UV gel around the base of the tube to give you a solid connection with no leaks.
attaching 2 tubes to GK is a bit tricky and it took me several attempts before I worked out a reliable method. I have come up with 2 solutions that both work pretty well.
method #1 is using standard sized acoustic tubing (AT from here on). The difficult part about using 2 tubes of this type on GK is that the distance between the CI audio port and the TWFK audio port is exactly the same as the wall thickness of the tubing, this means that you can only fit one tubing wall in between the two ports. In order to solve this, make a small diagonal cut out on the side of one of the tubes and than bond the two tubes together using UV gel. The result is 2 tubes that share 1 wall for a short section on one end. Next, attach the dual tube to the driver ports using the method stated above. You want to be careful on that last step not to cover over the driver ports, it is impossible to not cover the CI port partially since it is on the front of the driver, just make sure that it is not fully covered.
method #2 is to use heat-shrink tubing (HST from here on) instead of AT, The HST has much thinner walls and you can easily fit 2 of them together over the audio ports. Attach the HST using UV gel as noted above.
There are 2 down sides of using HST. One is that it has a slightly smaller internal diameter and it will be nearly impossible to fit a damper into the tubing if you decide you want to tune the sound further after assembly. The other is that the HST is less bendable then AT and if you bend it to much it will collapse at the bend, completely blocking the sound, AT will do the same thing but you can bend it further before that happens.
It is possible to attach the 2 types of tubing together if you want to make a mix of the two methods because the OD of the smallest HST is about the same as the ID of standard AT but jest keep in mind that the HST is more flimsy than AT and it will tend to bend first resulting in the tubing claps as noted above.
Good luck and have fun.
