simple crossover question.. clarifation

[ark]

I 've noticed that most people see to choose speakers where each overlaps more or less where the other falls off.

I am new to this so I wonder if someone could explain.

What if i have a speaker that is say 6" and nearly ruler flat from 80hz to 20k.

And I put it above a 10" speakers that is flat from 30hz to 1800hz..

Both are 93-94 db efficient at 8ohms

both have equal dimensions depth wise (time aligned)

There is a lot of overlap.

Would a first order crossover be simple? appropriate?

At what point would you cross over?


In case your curious the combination I had in mind are these
Supravox 165-2000 field coil
http://www.supravox.fr/anglais/mesures/mes165_20001.htm

And


TAD TL-1102
http://www.pioneerelectronics.com/pn..._34187,00.html

I was looking at both of these for completely different projects then thought.. what if i put them together? us a cone speaker above the tad instead of a horn or waveguide/dome horn thing.. etc.

any thoughts?

[angsuman]

Get a crossover modeling program such as Passive Crossover Designer. Also those drivers seem very esoteric and not worth their price...

A first order electrical crossover might be feasible it really all depends.
and you'd definitely need a tweeter to help out the 6in woofer.

[ark]

6.5 inch 'full range' over a 10 inch woofer.

anyhow, regardless of the "esoteric" drivers.

I was wondering if there was any problem crossing over two drivers at points where they are so flat vs. where the slopes start form..

?

[owdi]

There is more to choosing a crossover frequency than just a smooth FR. You also need to consider off axis response, harmonic distortion and energy decay.

For example, look at the off axis performance of the 6.5" full range. High frequencies roll off as you move off axis, but the midrange stays strong. Unless you are listening on axis, the speaker will sound dull. This is a problem with all drivers this size, which is why we use tweeters.

To answer your question, no there is no problem. If both drivers are flat in that area, then you can use a 1st order filter. If you plan on using only a capacitor as a low pass filter, you will need compensate for the impedance peak at fs of the full range.

Dan

[ark]

thanks dan.
that answered my question.

in this case both speakers have excellent off axis response.
initially i was planning on using the tads with horns up above, or a waveguide /horn.. then the xover became complicated.. the supravox i was thining about for an open baffle single driver project in another room.. then got to thinking.. it might actually mate well for an "all paper 2-way..

interesting. thanks a lot!