Modified Model 19 speakers

[yup]

Well... I may have spoken too soon.

When I moved the port to the bottom edge, I didn't take into account the speaker grill frame. At a minimum the frame will probably be the same thickness as the floor of the box (3/4"). It would then basically become part of the floor of the port. That would effectively change the tuning when the grill was on or off. (is this a correct assumption?)

As I see it, I have a couple of options.

1. Put the port back 1.75" away from the bottom edge

2. Make a double thick floor section for the depth of the port so that the grill does not effect the port tuning, but allowing the port to be along the bottom edge.

3. Something else...

Would I be able to hear a difference in either version anyway?

Thanks,
Jeff

[GM]

Greets!

I assumed the grill frame would increase the effective vent length 3/4" and since you're going to the trouble of making some nice grills, you should 'voice' it (fine tune)/listen with them on IMO. Regardless, with large vents, reducing vent length 3/4" doesn't raise Fb an audible amount. Indeed, depending on the grill cloth chosen and how taut it is tends to have the most audible effect, if any.

GM

[yup]

Well I have incorporated the changes to the cabinet and run some different sims with three different port lengths to show the range the enclosure can be fine tuned within (and compared to the 416-8C version of the original Model 19)...

The modifications as well as the response curves are all in this file: Modified model 19 enclosure

This now looks somewhat like a cross between a Model 19 and an Onken enclosure. It will take me a while to complete these, but I will post a follow-up here when I do...

Thanks for your input GM.

Thanks,
Jeff