Where i should put the tweeter?

[ramiro77]

Hi everyone!
I´ve ordered a pair of Peerless HDS 830875 and a pair of Seas H1189 tweeters.
I´m going to build a pair of bookshelfs, but i don´t know how i can calculate the distance between the midwoofer to the tweeter, and the distance between the tweeter to the side walls of the cabinet.
Basically the cabinet will be builded with curved walls and curved edges to avoid the baffle step.
Hope someone can help me.

[PeteMcK]

The tweeter should be as close to the mid-woofer as possible;

re: 'curved walls and curved edges to avoid the baffle step' - you're confusing baffle step with baffle diffraction, curved edges & walls will not avoid baffle step.

(Fortunately, baffle step isn't important in most bookshelf designs - but this depends on how you want to use them)

Diffraction from baffle edges

[head_unit]

Re " Where i should put the tweeter?"

Oh, sooooo tempting to give an anatomical answer

But yes, as close as possible to the woofer to reduce lobing at the crossover transition. Then for baffle diffraction, off-center if possible (but not too much as it tilts the off-axis response). Flushing in the woofer and tweeter also eliminates one more set of tiny reflections.

[nickf]

As others have noted, as close to the woofer as possible so that the sound pressure at crossover frequency from both drivers combines.

Next, place it different distances from every edge. The last time I tried to figure some optimal distances I placed the center of the tweeter 35% of the way across the cabinet horizontally and the distance from the top of the cabinet to the center of the tweeter was 45% of the width of the cabinet.

Hope this makes some sense...

[ramiro77]

Interesting!
So i will put the tweeter off center, i have enough space to do that. And closest possible to the midwoofer.
Flushing mount will be a must.

Thanks a lot for the answers

[jrenkin]

Originally Posted by nickf

As others have noted, as close to the woofer as possible so that the sound pressure at crossover frequency from both drivers combines.

Next, place it different distances from every edge. The last time I tried to figure some optimal distances I placed the center of the tweeter 35% of the way across the cabinet horizontally and the distance from the top of the cabinet to the center of the tweeter was 45% of the width of the cabinet.

Hope this makes some sense...

Maybe this helps?
Tweeter diffraction

Regards -j

[ramiro77]

Yes jrenkin, i´ve heard about tweeter diffraction and flush mounting.
I´ve heard too that the best proportion to put the tweeter is a ratio of 1.6 (known as golden number).
Casually, putting the tweeter at 35 percent of width, you are respecting the golden number (aproximately).
I will put the tweeter in that proportion, and midwoofer horizontally centered, closest possible to the tweeter.
What do all of you think?

[nickf]

You can use Edge software to simulate the effect of the position of a speaker on a baffle.
Home of the Edge

[ramiro77]

Well, i´ve been working with different driver´s positions according to suggestions and measurements, and i´ve found that this is the best:



The tweeter is off center. The woofer is placed in that position to take advantage of its truncated part, and thus bring it closer to the tweeter.
I know that it´s not the most aesthetic position, but according to measurements is the best.
What do you think about?

[cocolino]

Looks good to me!
Regarding 'aesthetics': I like it too, looks really fancy.