Need advice on dj/pa speakers

[ogp]

I would like to build a set of high power, decent sounding speakers for dj and sound reinforcement use. I really wouldn't want to spend much more than $300 or so for the drivers and crossover. I have found a design here, http://www.dancetech.com/aa_dt_new/pa/full-range-s.cfm. What do you think? Could anyone recommend drivers or another design? Also, I have read that you really shouldn't use a woofer larger than 8" for midrange, does this not really apply to PA use or is this just a bad design? I have never built a crossover and was wondering if anyone would have advice on this? I have read that active crossovers are easier to design but they require multiple amplifiers. Do you think it would be better to use an active or passive crossover on a speaker for this type of use? What about using this active crossover kit, http://www.t-linespeakers.org/pomann/crossover.htm? And when I choose drivers, do I need to make sure they all have the same resistance or is this compensated for in the crossover? I would also like to make these 4 ohm speakers as newer amps can drive these with more power...is this achieved with the crossover as well? Any responses are greatly appreciated.

Dave

 

[Super]

I think that a 10 inch midrange is definitely too big, unless your tweeter is designed to be crossed over VERY low. Whether or not this is the case for a bullet tweeter, I don't know. A piezo tweeter, for example, can be used without a crossover. Either way, a 10 inch driver for a midrange isn't going to perform very well in the upper midrange. DJ and SR speakers require a lot of bass, so a 15 inch driver would be suitable, and porting it will give it good slightly better power handling. When picking a 15 inch driver, I'd suggest getting one with a rubber surround: higher power handling and it will last longer. As for the midrange, I'd probably steer you more along the lines of an 8 inch driver.

I'd also suggest the use of an active crossover for DJ use. In some cases, you can buy one for about the cost that you can build one for. As for impedance, this is determined by the drivers themselves. Some active crossovers can compensate for impedances though, with a 4 or 8 ohm output, although it isn't the most common thing. It also isnt necessary to match the impedances of the driver, but it isn't a bad idea to do so. In general, no speaker impedance is exactly 4 or 8 ohms. It varies from driver to driver.

 

[km]

hi.

i have been making a living of designing and building these for 20+ years

feel free to contact me for suggestions and more...

bye k madsen - cadaudio.dk / km_cad@yahoo.com

ps. about your design (hehe) you can hardly call it that , to my best knowledge it was made for a celestion diy book 15+ years ago in 30 minutes (for the whole book) up to some fair

 

[ogp]

ok...so if I did go the active crossover route, the individual drivers would determine the amount of power the speakers could handle, right? I have read lots of information leading me to believe that getting the crossover right for a 3 way design is very difficult, would this not be the case for an active crossover? Are you able to adjust those as necessary with the crossover? I'm really new to the world of diy speakers and such, but I think it is a great way to get a better sounding product for less money. Since this is the first speaker I have built, I thought it would be better to go with someone else's proven design, but that was the only one I could find. All the other's are for home use. So do you think buying an active crossover from somewhere like partsexpress is the way to go? I have read that to get the best sound, it is better to design your own. Or does this not really apply in the active crossover area? Thanks again for the responses.

Dave