checking horn measurments are correct

i took another look at my measurments using your advice guys, i simed with dth of 11cm after using the methods above it should of been 11.6cm the plot smoothed out a little between 1k and 3k. smiley20 Still dont know how to sim a plug in akabak, but when added it should help even more. Im gonna start making up 1 horn this week then play with plugs etc. :geek:

ok this is a predicted plot of the mt121 12" section with my 6" section and 1" hf what do you guys think....



mind you it could turn out nothing like this smiley19

all B&C speakers

What is the xover points that your gonna use?
how do you sim the compression driver?

very interesting work! smiley20

around 1khz for the 12" to 6" and 2.5 for the 6" to the hf. the hf is the original plot b&c provide just over layed. the hf is a guess......... what do you think about the xover points.

SIMS !!! What's the point. I once asked everyone who had simmed a cab, whether, after the build and test, whether it was accurate. no one said it was the same, most people who answered said it was different.
I bring up this point, as I know from experience that you cannot fix anything like a crossover point form a sim. you have to measure the box and adjust accordingly. The sim doesn't show the phase reaction between the components and you certainly won't know how the x/o points will react in a real situation. Only when the cab is built can you do the proper job.

thanks tony, the xover i posted are are real guess... the horn could turn out nothing like i plan, smiley19 i hope it will, if it doesnt ill just start again till i get it right smiley27

When cabs are built do you have anything to measure the response with.

i have a copy of arta but nothing propa........

Arta does quite a good job, not that I have anything more exotic to compare it with.

The other programs with it are quite useful for doing impedance, distortion and phase plots. I'm still not there yet with the phase plots, I just get a crazy zig zag line, off the top then back on at the bottom several times, I've heard talk of needing to 'unwrap' the plot, but haven't figured out how yet.

As well as the software you will need a reasonable mic and phantom power, several resistors and bits of wire. I use a berry ecm8000, not the best mic but fine for doing comparisons with.

Have you made a start on the sawdust pile yet?

Kieran

yep the first 3 layers of fibre glass are on, and the moulding of the flare is well under way ill post pics soon...