Round vs. rectangle ports...

[RockysDad]

Is there any audible difference between these two types of ports? Right now I have a pair of Bob Brines first version of the FT-1600 with Fostex FE167e drivers in the ML-TL with the rectangle ports on the front. I was thinking about cutting about 3.5" off the bottom and then add the 3" round ports like the second version he has now.

Should I leave well enough alone or cut it and add the round ports? It sounds pretty good now but could it get better? If so, how? More extension, better control, less flabby? What are pros and cons of each type of port?

TIA...

[Geek]

As long as the wind velocity remains below the "huff", personally I haven't heard much difference.

[Scottmoose]

With a non rectilinear port you tend to get less ripple in the mid-bass -from, say, 250Hz-1KHz. You can improve matters still further by raising the port a few inches from the base of the cabinet.

If you've got the MK1 version of the FT1600, you've got a superb speaker (I had some myself too). The MK2 is better, but looking at the response, I can't see that there's much in it -probably not enough to much about re-jigging the whole pysical cabinet design. Fine for a semi-production speaker of course, and in Bob's case well worth doing, but for exisiting owners? Probably not. Buy some more music instead.

Easier tweaks: 1) reduce the amount of stuffing from the original specification if you haven't already, especially from behind the driver. You could even remove the lot and line the cabinet with the hard acoustic fibreglass Bob uses for the MK2. The MK1 cabinet has a touch more ripple, but I reckon this will give a somewhat more open sound (not that the original is lacking in that respect.) 2) You might also try loosing the Zobel part of the BSC circuit. After all -you can always put it back.

Best
Scott

[RockysDad]

Easier tweaks: 1) reduce the amount of stuffing from the original specification if you haven't already, especially from behind the driver. You could even remove the lot and line the cabinet with the hard acoustic fibreglass Bob uses for the MK2. The MK1 cabinet has a touch more ripple, but I reckon this will give a somewhat more open sound (not that the original is lacking in that respect.) 2) You might also try loosing the Zobel part of the BSC circuit. After all -you can always put it back.

Been there, done that... Well, I 've been playing with the stuffing a bit and taking more and more out each time and finally found the right amount and have been listening to it for awhile now. I haven't tried the blanket type of lining yet and might give that a try.

Got rid of the Zobel awhile ago and added a 3 ohm series resistor to the BSC circuit, added the $.99 tweak, and added caulking to the basket and magnet behind the drivers. For the top end, I added the RS super tweeter with cap and L-pad to sweeten things up just a tad.

Overall, I am quite happy with it, just thought I could make it a bit better. The last thing might be is to add a sub woofer for some punch on the bottom end.

Thanks for your help, Scottmoose...