bass cabs

[drf]

I am thinking of building a bass cab, just wondering what allignments people curently use and what particular sonics they attribute to specific allignments, I am not overly concerned about the particulars of what each size driver should be capable of, but more what peoples impressions are.

For example I was thinking of a single 15" cab with a 2x 12" cab ontop, the idea being low end and a certain amount of projection in the one stack. Maybe even some piezo tweeters to compliment the 2x12"'s ?

cheers

dr f

[Bryan Nemecek]

drf wrote:

I am thinking of building a bass cab, just wondering what allignments people curently use and what particular sonics they attribute to specific allignments, I am not overly concerned about the particulars of what each size driver should be capable of, but more what peoples impressions are.

For example I was thinking of a single 15" cab with a 2x 12" cab ontop, the idea being low end and a certain amount of projection in the one stack. Maybe even some piezo tweeters to compliment the 2x12"'s ?

cheers

dr f

Are you are building the speaker box, or buying a box to put a speaker into? Will the box be ported?
Is this bass speaker intended for 'sub' duty?
What will the sound duty of the 2x12's be, to produce 'full range' sound?
You mentioned tweeters, will this system be actively or passively crossed-over?

You may want to post your question over in the "DIY Speakers and Subwoofers" area.

B-DoGG

[Wayne A. Pflughaupt]

drf,

Is this for PA use? The reason I ask is that your driver compliment seems peculiar. Usually PA’s use 18” horn-loaded subs, 15” woofs for the mids, and compression drivers for the highs.

Regards,
Wayne

[drf]

sorry, I meant bass guitar cabinets. I am currently designing a head amp. But I wanted some opinions on the different qualities each particular setup has:

E.g

do 4x10" cabs generally have a crisp sound? and or does a single 15" generally have a boomy quality?

I realise a lot of tone is dependent on many things like driver quality, application and environmental accoustics, however I am just after general feeling or impressions as I haven't had the opportunity to compare varying setups.

My idea with the 2x12"s was a single cabinet with some tweeters to get the higher freq's.

I haven't thought about crossovers because I usually decide/design those to suit whatever driver arrangement I have settled on.


edit: just learning how to use google sketchup, this is something along the lines I was thinking but haven't done any mathes and is not to scale:
basscab.JPG

[Danny]

Question - if it is a bass guitar cab why are you putting tweeters in it? IMO they are unneeded.

[drf]

IIRC Bass guitar has harmonics upto 2khz, with some snap and edge definition above this (5 to 7Khz is not unheard of). The average 12" driver can breakup at 2Khz. This, to me, seems to leave some of the defining characteristics of the instrument to the mercy of a larger drivers high end ability. So I figure a tweeter or 2 could relieve the drivers of this burden.

[Sonnie]

I believe large full range drivers are available aren't they? I'm thinking those who do the Open Baffle type systems.... they use full range 15" drivers. Could you use those okay?

[Wayne A. Pflughaupt]

Danny wrote:

Question - if it is a bass guitar cab why are you putting tweeters in it? IMO they are unneeded.

drf wrote:

IIRC Bass guitar has harmonics upto 2khz, with some snap and edge definition above this (5 to 7Khz is not unheard of).

Not to mention, the highs from large-diameter drivers is very directional and “beamy.” So everything sounds very different to listeners who are in front of the cabinet, vs. listeners who aren’t.

do 4x10" cabs generally have a crisp sound? and or does a single 15" generally have a boomy quality?

I never could fully get behind the 4-10 arrangement, always seemed to lack in the lowest frequencies.

Interestingly, there is a migration in bass cabinets these days towards 12” drivers, as a “best of both worlds” between the 10s and 15s. I played on a little Aguilar 1-12 w/ tweeter several months ago, and it’s arguably the best sounding cabinet I’ve ever heard. Great extension, even with a 5-string, and very smooth and linear from the low notes to the high, no “boominess” or one-note quality. I want one!

If I was going to do a custom rig like yours, I’d do it like they do with home speakers, not like they typically do with bass cabinets. With bass systems, they typically have the big driver running full range and handing off the upper frequencies to the smaller drivers. What I’d do is run the small drivers as low as they’d play, then hand off the lower frequencies to the large driver. Naturally, this will require bi-amping with a good electronic crossover.

I’d also pass on peizo tweeters, as those things are pretty cheap and nasty-sounding, IMO. I’d go for a good-quality horn-loaded compression driver, like they use in PA systems. Makes perfect sense, especially if you’re going to be patched into a PA system anyway: what you here on-stage will be a better match for what your audience will hear of you from the system.

Another thought, if you’re going to be patched into a PA system with subs, you can dispense with the 15” altogether and let the system carry the bottom end for you. After all, what’s the point of trying to make a 15-incher compete with a pair of horn-loaded 18” subs??

You might want to bounce your question off the guys at the Talkbass Forum. Lots of good, informed advice there.

Regards,
Wayne

[drf]

Thanks, I have no problems with bi-amping, to be Honest I much prefer active crossovers/biamping to passive.

If I was going to do a custom rig like yours, I’d do it like they do with home speakers, not like they typically do with bass cabinets. With bass systems, they typically have the big driver running full range and handing off the upper frequencies to the smaller drivers. What I’d do is run the small drivers as low as they’d play, then hand off the lower frequencies to the large driver. Naturally, this will require bi-amping with a good electronic crossover.

That sounds like a good idea, I could set out the amp to have a selectable crossover so a 15" cab can be added at a future date. Only problem with that is I didn't really want to build three poweramps for the one head, just two. I suppose I could have a pre out that is low passed, then just add a third amp when using the 15.

I believe large full range drivers are available aren't they? I'm thinking those who do the Open Baffle type systems.... they use full range 15" drivers. Could you use those okay?

I could use those, but even the best built 15" drivers will suffer cone breakup after 1-2Khz. In some cases they barely make it to 1Khz before breakup can be measured/heard.

[Sonnie]

Wayne A. Pflughaupt wrote:

Not to mention, the highs from large-diameter drivers is very directional and “beamy.” So everything sounds very different to listeners who are in front of the cabinet, vs. listeners who aren’t.

drf wrote:

I could use those, but even the best built 15" drivers will suffer cone breakup after 1-2Khz. In some cases they barely make it to 1Khz before breakup can be measured/heard.

I wonder how the likes of Hawthorne Audio get their OB (open baffle) systems with full range drivers to sound good... and they use those for home theater and two channel. They actually have some pretty good reviews too. I think we have someone who is writing up something on their OB's and it may give us some insight. It just got me thinking that they must have better full range drivers available somewhere.

[drf]

I don't know much about Hawthorne Audio or Open baffle setups, suffice to say I believe in order to get them to sound better than everyday "run of the mill" speakers you have to spend quite a lot of time building and measuring. Also I think those drivers will probably still breakup and beem (because they are used full range?), as breakup is a function of the sound wave in relation to the cones radius, and the material of the cone's ability to dissipate its energy into sound pressure. Not that I want to question hawthorn audio, I just simply don't know enough about there product to understand how they overcome issues like cone breakup, and IMD.

You are right though, there are good full range drivers out there, Fostex come to mind, but if I were to use them for instruments or SR they'd probably burnout very quickly.

[Danny]

While we are talking about bass cabs and guitars. Does anyone know if it is alright to use a sub and amp instead of a dedicated bass cab. I have the sub and amp lying around and don't want to buy a bass cab unless i have to

[drf]

It should be alright, just watch out for excursion limits on the sub as any guitars dynamic range is much larger than the average Hifi/HT signal. A good whack on the strings with too much gain in the amp could blow your speaker. You may also need a pre-amp depending on your sub amp and guitars pickups.

How serious are you about playing? you may be better of investing in a little practice amp or DIY'ing a nice little combo.

[Wayne A. Pflughaupt]

What drf said. Don’t expect to play it at the levels you would a regular bass amp. As long as you keep the levels moderate, you’ll be fine.

That said, don’t expect it to sound all that great. Home subs typically fall off rapidly above about 150 Hz when used full-range, so expect your higher notes, especially up towards the second octave of the G string, to sound weak (reduced level). Also lacking will be the second and third harmonics that give your instruments its tonal quality or “voice.” Basically, it’s probably going to sound pretty flat and lifeless.

Regards,
Wayne

[Danny]

I had a look at the spec and it has a reasonably flat response until about 2000 - 2500 Hz but then it drops off quickly. Levels should not be a problem - playing music it goes at about 120Db. I'm only using a 400watt amp and the driver can handle up to 600 so it should be hard to overload it, will have to watch the amp for clipping though. May invest in a proper setup when i have cash.

[Randall R. Dibble]

I just learned of this site today.

It looks good!


I hope I'm not intruding in this thread but as a Bassist who has built many bass speaker cabinets I suggest you check out Bill Fitzmaurice website.

There a number of good designs for Bass Guitar speaker cabinets for sale.

I myself use a Omni-10 with twin Eminence BP102 drivers.

He has forum that supports builders these designs as well.

Also some myths regarding speaker design and placement are revealed.


Check It out!

http://www.billfitzmaurice.com/

http://billfitzmaurice.com/phpBB2/

[BoomieMCT]

Randall R. Dibble wrote:

I just learned of this site today.

I myself use a Omni-10 with twin Eminence BP102 drivers.

I always wondered about those Omnis. Do they dig low enough to be used with a bass by themselves, or do they need a sub to fill in the fundamentals?

[Randall R. Dibble]

I use my Omni-10 with Bp102's in small to medium club's and a Tuba24 with the larger clubs and outside. I bi-amp when using the tuba with a Behringer Bass V-Amp Pro pre-amp and a Peavey CS800 to drive the full setup.

The Omni-10 by it's self works great in most Situations and it's a relatively small in size.

[drf]

Well, I have started work on the 2x 12 cab. I have decided to make it from Chipboard for a couple of reasons:

1, it only has to last 2-3 years, before I get bored and want something different.
2, its my first attempt at a 2x 12 so I don't want to spend extra cash on a design that has the potential to flop.

have decided to go with the cheaper piezos because of what I read on the site linked by Randall R. Dibble (thanks for your thoughts). If they don't work in this box I can always replace them with some decent compression drivers.

current design will have an FR from 40 to 15Khz, with a modeled response within 6dB variation.
200Watts RMS @ 4ohm.

hopefully I'l get pics up soon.

cheers Drf.

[WillyD]

drf wrote:

I am thinking of building a bass cab, just wondering what allignments people curently use and what particular sonics they attribute to specific allignments, I am not overly concerned about the particulars of what each size driver should be capable of, but more what peoples impressions are.

For example I was thinking of a single 15" cab with a 2x 12" cab ontop, the idea being low end and a certain amount of projection in the one stack. Maybe even some piezo tweeters to compliment the 2x12"'s ?

cheers

dr f

Interesting thread!

I too have been brainstorming a bass cab for myself. I just bought a Behringer CX2310 for xover use, and as of now I think I'll be going with a 15" woofer, maybe two 8" midwoofers, and a decent compression driver. I'll be shooting for full range performance so I can use the cab for anything.

I haven't chosen the drivers yet, but so far I like the BMS 15N630 for the woofer.

http://www.assistanceaudio.com/02_BMScones.html

http://www.bmspro.info/

[drf]

That BMS woofer looks like it would benifit from being in a horn loaded enclosure, either a front loaded or folded horn arrangment. Then stack on top of that a 2x 10 mid cab with compression horns and you should have a pretty sweet sound. Have checked out Eminance drivers, reports say they are very robust speakers and can take fair pounding.

[WillyD]

Really? I never thought of that. Was just gonna put it something like 120 liters ported enclosure, tuned to 30Hz. And I am going to choose my mids carefully. I want them to play up to the xover point of the compression driver, and abit past it, cleanly. I don't think 10s will do that for me. Hell, I'll probably be crossing the BMS (or whatever woofer I choose) at 250Hz, or so.