The 15'/6'/1' Bass Cab Appreciation Thread!!

[faulknersj]

Ha! Indeed monkeyking! I want to hear that whole wall of cabs fire off at once. That would be a real rig of doom!

 

[tocs100]

Correct, because once you put in a crossover between the two, the impedance doesn't work like combining series cabinets.

I realize that's the case with active x/o's, as I design 'em all day long. But not with passive x/o's? A tiny bit of techno-explaino plz? Just as long as I'm clear on that it'd save me (and others here) a bit of reading and I could in turn focus on imparting advice on stuff I'm more familiar with, etc. etc.

For example, this neat crossover site and modeler shows that I could solder a __microfarad capacitor in series with an 8ohm Eminence Alpha 6" (or for my needs 2 4ohm Alphas in-series) and get a 6db rolloff below 500Hz. That's still a chunky bass response between 500Hz & 125Hz, while still being down 24db at 30Hz.
http://www.bcae1.com/passxovr.htm

Then, if I wanted to run my 2-Alpha-6"-cube with my fEarful 8ohm sub in parallel, my stack would be 4ohm, and the crossover, reacting to the new impedance, would raise its rolloff point to 1kHz, which would be perfect for when cranking the stack. I'd also get 3dB insertion loss to the cube due to the capacitor/crossover, so the cube would be automatically padded a bit.

Right? Wrong?

There's also other reasons the idea isn't that sound. At a lower crossover point like 100 or 125 Hz it'd almost be worth doing. So much of the information I've tried to impart in fEARful and other threads would lead one to that conclusion - or to resources that would. Part of the glory of DIY is that people can learn stuff.

Anyway. It's more efficacious to have a dedicated monitor for the drummer, one that is dealing out both bass guitar and whatever else he wants to hear more of, which almost always seems to include kick. And guess what works real well for that?

But I just bought a fEarful sub today to cover weak front-of-house woofers and will be eating Ramen 'til Thanksgiving to cover it (vs. making do with a Carvin PA speaker I just sold for peanuts)
And I find lots of bass-content in monitors is actually a nightmare near the drummer cuz they bleed and feedback thru the drum mics, So I end-up having to run a separate mix to the drummer and hey darnit I'm the bass player, hired to play bass, and not the (often absent or resource/knowhow-strapped) club soundguy.

 

[tocs100]

^Added question. Please bear with me if I'm missing crucial, subtle factors like notch-resonance, etc. Online articles go-off on that stuff w/o answering my basic design question. Just trying to grasp the basics, then I'd hire a pro, or better yet make it a TB project.

For example, this neat crossover site and modeler shows that I could solder a __microfarad capacitor in series with an 8ohm Eminence Alpha 6"s (or for my needs 2 4ohm Alpha's in series) and get a 6db rolloff below 500Hz. That's still a chunky bass response between 500Hz & 125Hz, while still being down 24db at 30Hz.
Passive Crossovers

Then, if I wanted to run my 2-Alpha-6"-cube with my fEarful 8ohm sub in parallel, my stack would be 4ohm, and the crossover, reacting to the new impedance, would raise its rolloff point to 1kHz, which would be perfect for when cranking the stack. I'd also get 3dB insertion loss to the cube due to the capacitor/crossover, so the cube would be automatically padded a bit.

Right? Wrong?

 

[tombowlus]

And now we know why the magnetic poles are shifting - they're being drawn to tombowlus' wall o' 15's!

That is but a small sampling of the Bowlus Bass Borg.

 

[Sundogue]

That is but a small sampling of the Bowlus Bass Borg.

No kidding. I think Tom has the largest collection of bass cabs in the world.

Word has it Tom once stacked up all his cabs in his back yard and people came from miles around thinking there was going to be a Grateful Dead concert.

 

[tombowlus]

Word has it Tom once stacked up all his cabs in his back yard and people came from miles around thinking there was going to be a Grateful Dead concert.

LOL!

 

[Foz]

...and then there was a Grateful Dead concert.

Damn Tom that fEarful stack just looks so cool the way the mids lock up

 

[BurningSkies]

I realize that's the case with active x/o's, as I design 'em all day long. But not with passive x/o's? A tiny bit of techno-explaino plz? Just as long as I'm clear on that it'd save me (and others here) a bit of reading and I could in turn focus on imparting advice on stuff I'm more familiar with, etc. etc.

For example, this neat crossover site and modeler shows that I could solder a __microfarad capacitor in series with an 8ohm Eminence Alpha 6" (or for my needs 2 4ohm Alphas in-series) and get a 6db rolloff below 500Hz. That's still a chunky bass response between 500Hz & 125Hz, while still being down 24db at 30Hz.
Passive Crossovers

Then, if I wanted to run my 2-Alpha-6"-cube with my fEarful 8ohm sub in parallel, my stack would be 4ohm, and the crossover, reacting to the new impedance, would raise its rolloff point to 1kHz, which would be perfect for when cranking the stack. I'd also get 3dB insertion loss to the cube due to the capacitor/crossover, so the cube would be automatically padded a bit.

Right? Wrong?




But I just bought a fEarful sub today to cover weak front-of-house woofers and will be eating Ramen 'til Thanksgiving to cover it (vs. making do with a Carvin PA speaker I just sold for peanuts)
And I find lots of bass-content in monitors is actually a nightmare near the drummer cuz they bleed and feedback thru the drum mics, So I end-up having to run a separate mix to the drummer and hey darnit I'm the bass player, hired to play bass, and not the (often absent or resource/knowhow-strapped) club soundguy.

Without going into details because:
A) I'm not really fully versed in passive crossover design
B) There are people here who are waaay more on top of this than I am as well as being really knowledgeable about the other variables that can effect the end performance of your speaker setup...

I'll say this. The standard fEarful combines two 8 ohm speakers...and still is conservatively rated an 8ohm cab. Its not rated a 4ohm cab. This is because of how the impedance curves work for each speaker and how the crossover passes lows and highs to its speakers. I'm sure you know that impedance in speakers is a moving target in a few ways. But here, what you're getting is each speaker being fed different signal, therefore their impedance not being a fixed value across whatever is being presented, but also since the mid (or in your case multiple mids) are being fed well above where they're hitting their rated impedance you're not getting a 5ohm (actually 5.3333) load out of it one way or another.

 

[greenboy]

The acoustical factors of why it's not going to work well to point just an 800-Hz-and-up source at the drummer have to do with directionality. The 15" woofer has become increasingly directional by the time it reaches 800 Hz. Definitely by 200 Hz it begins to sound disembodied having the woofer at 90 degrees angle from a mid source that's also above it. And it gets worse as frequency climbs. There's a lot of weird combing too that notches out real deep. Between the disembodied SPL mis-match and the tendency to hear way too much reflected sound from the woofer compared to its direct output, it's going to be a disconcerting smeary mess that in most environments could actually be distracing to hear, rather than helpful.

...I often drag my Carvin LS1503 to loud gigs for a drum monitor, because with its retrofitted 3015 it can handled as much bass guitar and kick as the drummer needs and then some, as well as any other stuff he wants in the mix. But often it's just set up correctly on the given stage size, and he can always hear me. If I was using 12/6cube atop the 15/6 (or vice versa) I could turn one or the other toward him at 90 degrees, but usually it's just 12/6cube, or 12/6cube atop 15sub.

EDIT: My conclusion using a lot of biamped rigs and doing SR is that any higher than around 200 Hz at the most is crazy for some 90 degree source placement as described earlier. 100-125 Hz would be better. 800? Not even. One merely needs to hear an 800 Hz and up source (like a Headcase) to determine it's not suitable for monitoring anyway. You need integrated lower midrange to even begin to have something substantial.

 

[BurningSkies]

I thought I'd also post this:

Link Removed

If anyone is interested in tackling the nuts and bolts of crossover design, this is the software to use. The online calculators are pretty light weight and surface value only.

I haven't personally had any real experience with it because I'm happy with the CBG in my 15/6 and I fear that I tend to get into pointless, expensive and obsessive hobbies too easily.

 

[BigGuns]

Not one of those cabs has a 15-foot woofer or a 6-foot midrange cone.

I know, what the hell.

 

[lomo]

Word has it Tom once stacked up all his cabs in his back yard and people came from miles around thinking there was going to be a Grateful Dead concert.

ROFLMAO

 

[tocs100]

Great info from Greenboy here, but I just want to clarify some minor spec-stuff, as after 3 "no's" via pm's here I found a guy who will at least experiment with a protoype of my dual-6"-cube. Yes, there will be anomalies, like Avatar's tb153, but plenty are liking that cab. I just wanna come-up with something inexpensive that fills a niche and doesn't depend on others' designs, as I need some small income from music-tech stuff (esp. after 2 builders ran-off with my c/o-eq-pedal design). Others too, like me, have physical disabilities meaning they must buy premade products rather than being able to diy stuff--even from kits.

The acoustical factors of why [tocs' original specs for his dual 6" cube] it's not going to work well to point just an 800-Hz-and-up source at the drummer have to do with directionality. The 15" woofer has become increasingly directional by the time it reaches 800 Hz. Definitely by 200 Hz it begins to sound disembodied having the woofer at 90 degrees angle from a mid source that's also above it... the tendency to hear way too much reflected sound from the woofer compared to its direct output, it's going to be a disconcerting smeary mess that in most environments could actually be distracing to hear, rather than helpful.

...I often drag my Carvin LS1503 to loud gigs for a drum monitor, because with its retrofitted 3015....

EDIT: My conclusion using a lot of biamped rigs and doing SR is that any higher than around 200 Hz at the most is crazy for some 90 degree source placement as described earlier. 100-125 Hz would be better. 800? Not even. One merely needs to hear an 800 Hz and up source (like a Headcase) to determine it's not suitable for monitoring anyway. You need integrated lower midrange to even begin to have something substantial.

^Gotcha. I've done the full-range to the drummer and have a list of pros and cons. Some cons include bass-bleed into the drum-mics, and just overkill in basements (wives will love the efficient, bell-like mids and lack of woofing, lol) and on small-stages. Taking gb's advice, I decided on a rolloff slope at 125Hz when load is 16ohms (barely noticeable when using the cube alone) but about 350Hz at 5ohms (that is, when combined with an 8ohm cab. Again, no crossover involved, just a 1-cap passive rolloff on the 2 mid-drivers.) And the slope is only -6dB per octave, so there'll still be lots of chunk around the still-"embodied" 175Hz. The 4-octaves between 250Hz-4kHz will be perfect though--unlike 10"s which scoop there so when you bi-amp them you don't get much more than a hissy tweeter. :=( :=( (I despise 10"s! lol.)

Forget the calculators. Start working with driver data for specific drivers in specific enclosures....Forget about slopes and third order this second order that and BW and LR because it's all just an approximation construct that fails to address the realities you will find.

^This stuff is just beyond me. Unless someone wants to volunteer any advice, I'll just have the 2 Eminence Alpha 6a"s mounted in an 8" square cube. (I think my builder has driver-data-software too.) The single-cap rolloff defeats the low-bass, so I don't see the need for porting--it's basically just 2 mid-boxes combined, but angled 90-degrees away for versatile dispersion. I want to use this with my guitar amp too.

Last quote below here links to others besides here curious about a simple (under $300), mid-satellite better suited than a tweet or a (scooped) 10":

...[make] a decent 2-way rig?
Was thinking that all the guys with TL606 cabs, could build a very small cabinet with an 8" mid and a simple crossover for cheap.
Would this be an improvement or a waste of time and money?

 

[thouser1]

Come on tax money, I'm in!

 

[thouser1]

Anyone running two of the TB153's or would this be too much of a good thing?

 

[faulknersj]

Thouser, I only run 1 TB-153 and it kills! The only application I could see needing 2 of thes for isinsanely loud heavy rock, thrash, metal, etc. One of the beauties of this cab is that it is a 1 cab solution for most of us.

 

[faulknersj]

I have posted this on other threads, but here is new video from a live gig with my 73' Fender jazz with chrome flats, my Genz Benz Streamliner 900, and Avatar TB-153 15inch 3 Way Cab. It sounds exactly like it did to me in real life in the video.

YouTube - Genz Benz Streamliner 900+Avatar TB-153 The JJ's Band

 

[BurningSkies]

Thouser, I only run 1 TB-153 and it kills! The only application I could see needing 2 of thes for isinsanely loud heavy rock, thrash, metal, etc. One of the beauties of this cab is that it is a 1 cab solution for most of us.

Or reggae.

Keep in mind, any time you're playing music that emphasizes lows, it'll help to keep your cabs alive longer if you have more drivers. Once I moved to a double fEARful setup, I found I could stop boosting my lows almost entirely. Less stress per speaker equals happier speakers.

 

[thudfromafar]

I have posted this on other threads, but here is new video from a live gig with my 73' Fender jazz with chrome flats, my Genz Benz Streamliner 900, and Avatar TB-153 15inch 3 Way Cab. It sounds exactly like it did to me in real life in the video.

YouTube - Genz Benz Streamliner 900+Avatar TB-153 The JJ's Band

sounds good, and it looks like you are having a real good time! haha

 

[faulknersj]

Maybe 3 too many scotches thudfromafar!