Driver selection question for a 3-way bass guitar cabinet

[fandsen]

Im planning to build a 3-way bass guitar cab using the PRV 3 way 1.2k/2.5k crossover..

http://www.parts-express.com/prv-audio-3df12k-25k-3-way-passive-speaker-crossover--294-2861

What drivers and enclosure size/tuning do you guys think would give me the best results from a price/performance standpoint?

[Chris Roemer]

Re: Driver selection question for a 3-way bass guitar cabinet

I did a 2-way bass once, but why a 3-way?

[fandsen]

Re: Driver selection question for a 3-way bass guitar cabinet

I did a 2-way bass once, but why a 3-way?

I have seen a few bass cab 3-way designs with a large woofer on lows, sealed back midrange on the mids, and a tweeter or compression driver up top.. which got me interested in the project. I assume splitting the LF/mid duties between a large woofer and a smaller woofer allows them to function with less distortion, since they are being fed power closer to their designed frequency range. I also assume this layout reduces beaming since the uppermid frequencies are crossed over to a smaller diameter midrange woofer?

Your question does bring up an interesting point though.. would I be better off using a 2-way crossover at 2khz or so and ONLY having a 15 inch woofer + a sealed back mid? OR even going with a 15 + compression driver and essentially building a very nice PA cabinet that is large enough/tuned low enough to be used for bass guitar? I guess it boils down to how good/bad a nice pro audio 15 inch driver sounds when being fed everything from 50hz-2khz. I have little experience with 15's in the $150+ range, so perhaps someone can weigh in on this?

[wg_ski]

Re: Driver selection question for a 3-way bass guitar cabinet

First off, that crossover is a 2.5 way, not a 3 way. It was intended for a 2 way dual 15x1" with baffle step correction (the 0.5 woofer). Implemented right they sound very good, but I have my doubts with the HF driver crossed at 2.5k. A real 3 way would have a dedicated mid (6 to 10 inch) and be crossed lower between the 15 and the mid.

There are a few 15's that will "go" up high and not sound too bad doing it. Off axis will not be good, but they don't sound "awful" as instrument speakers. Something like a Delta Pro 15 - with a low moving mass, small voice coil/dustcap, and semi-exponential cone. Not real good over 100 watts because of limited displacement and cone defomation. But I do like the way those things sound run full range - like in the old vacuum tube days when you couldn't overpower it. B&C has some nice stuff too, but the prices are higher. Performance tends to be better, but you still can't get rid of the beaming effect.

If you used a sealed back mid, you'd probably want low crossover 500-800 Hz, and upper crossover 2-3k (depending on mid size and HF driver capability).

[tron]

Re: Driver selection question for a 3-way bass guitar cabinet

Well I thought about it and wondered why you wanted to build a 3 way. I looked over at my Bass rig and I actually use a hybrid 3 way. My head is an Ampeg SVT4 which is a two channel rig with an electronic XO. The speaker system is 4X10" EV and Brand X horn tweeter in one cab and 1X15" Eminence Magnum in another cab. The 4X10" + horn cab sits on top of the 1X15".

I run the SVT4 in Bi-amp mode with the Xover set around 150hz. The 15" gets 150hz and down and the upper 4x10" + horn gets 150 and up. The Horn has a cap and a coil on it as well as an adjustable Lpad. So I guess what I am saying is I have a 3 way bass rig.

I did not design the 4x10...it is a Peavey cabinet with EV speakers in it. I went to EV when the cabinet went out of warranty. I got tired of replacing them! I built the 1x15".

I really like this type of rig. The 4x10" punch through the stage mix really good and the 15" just makes it dig a little deeper. I have been using this rig for over 10 years and I love it. It has the powerful punch of multiple 10's and the low end of a 15". The horn is also nice for clarity when slapping. THIS RIG HAS PLENTY OF STAGE VOLUME! Did I say that loud enough?

I hope this helps. If you decide to go with a 3-way I would use an amp that will Bi-amp or use a commercial amplifier with an electronic Xover.

ToddT