For the fronts I plan to make some high end DIY towers... Heres my dilemma though what driver to use for the fronts? Right now the drivers I have next to me as I type are...
Hiq OWII-FS
Scan Speak d3004/6600
Scan Speak 18s Rev
Scan Speak 15w Rev
I have a passive network designed by madi through the LEAP for the 6600 and 18s, it sounds great but I think it can be better, as the design wasnt done w/ the baffle. So Im looking to re do to get it optimal. For the passive this time I will have it once again designed on Leap but with the measurements taken from the baffle. I just dont know what drivers I should use and what would give me optimal results to mesh well with the subwoofer.
...I've thought about adding another 18s and doing a MTM, and I've also thought about doing a 6600, 15w, 18s three way, but it would prob be better to use a larger driver for the midbass, so Ive thought about adding a 10" woofer.
You've got some first rate drivers and it would be a shame to use anything but a first rate crossover for them. It seems you understand quite a bit about speaker design, but you don't have the tools or experience to design your own crossover. Nothing wrong with that, just ask for help. You already get the concept of mounting the speakers in the cabinet first before dealing with a crossover. This would select the baffle width and narrow down the choices for a baffle step compensation circuit that will be part of the crossover network.
I would get another 15W Revelator, combine it with the Hiquphon OWII ¾" tweeter in an MTM tower. With the right crossover, you could have transparent clear sounding midrange and excellent off-axis dispersion. I've never heard the 6600 tweeter and it certainly seems good on paper, but the Hiquophon ¾" tweeter will do better at off-axis dispersion than any 1" tweeter no matter how good it may be.
Both those tweeters are much more sensitive than one of either those woofers. If you use two woofers in an MTM, you won't have to pad down the tweeter response so much. Too much use of resistors to lower the response of tweeters always runs the risk of sucking the life out their sound.
Depending on your cabinet design, you might get good bass response as low as 35-40 Hz. As a guess, two 15W drivers would do well in a vented cabinet tuned somewhere around 30-45 Hz - I don't think you need larger woofers. Your subwoofer could fill in below that.
The reason I would rather use the 15W over the 18s is the high frequency response of those drivers. Look at the spec sheets from Madisound for the
18s and the
15W. (did I pick the correct drivers?) With the 15W woofers your speakers will sound smoother across the upper midrange. About 2 kHz and higher, the 18s goes into break up mode. It could sound harsh and glaring unless those peaks are filtered out enough so you don't hear them. I don't think the LEAP designed crossover from Madisound will suppress that break up noise enough. And either of your tweeters will have trouble being crossed over low enough to avoid the 2+ kHz noise. The 15W has also has elevated response at 2 kHz and higher, but it looks much better at those freqs than the 18s driver. An experienced crossover designer should be able to filter those properly.
If you click on the link for the SongTower QWT speakers in my signature line below, you can see a very similar design using the same tweeter and less expensive SEAS CA15 woofers. If you email Dennis Murphy, the designer of those speakers, (go to
http://murphyblaster.com/content.php?f=main.html and look for his email link on that page), he just might be interested in designing a crossover for that combination of drivers. He often likes doing this kind of work for DIY builders who don't have measuring and design tools of their own. Contact him and find out if he is interested and what you would have to send him (drivers, baffle, or cabinet) so he could do his own measurements and design a crossover that will be much better than anything you could buy.
