[Duke]

Anyone who plays bass guitar here, what would you like to see in a bass cab?  From perusing a bass guitar forum or two, there seems to be a trend towards lightweight cabs and two or three-way cabs (with a midrange and/or tweeter to give a bit more top end). 

I'd be interested in hearing thoughts on bass cabs from any audiocircle members.

Thanks,

Duke

[Drofo]

Hey Duke,
I am kind of old school and have to admit that i like the sound of the Ampeg SVT (8 x10") rig. However I have absolutely no desire to hump something like that around.  What i use is  a 2x10' plus horn in a small cab. I can stack another 2x10 if needed. That is a good combo of size output and portability.  Really for most venues, that is sufficient for stage volume.

While 10's can sound good, they don't have the same weight as a good 15". Maybe you could do a 2x10, plus HF driver plus a 15 in a separate cab. If stackable and roughly the same size, that would be versatile little unit. I am not sure if you could cross the 15" high enough to add a HF driver, but that would really increase the versatility.

Here is one time I would really be thrilled to see the Law broken. Hoffman's,  that is.

Regards,

Drofo

[Duke]

Thank you, Drofro.

I presume your 2x10 plus horn is an 8-ohm load, and then you parallel it with another 8-ohm
 2x10 - is that correct?

Does the other 2x10 also have a horn?  If not, do you change the level of the horn in the first 2x10, or just use tone controls/eq to correct?

The modular system you describe does sound attractive.  I was thinking about a modular system with a single (maybe 12") woofer in the smaller box, as there's not much to choose from among 4 ohm (or 16 ohm) 10" drivers.  Also, I don't like what happens to the horizontal polar pattern when two 10's are placed side-by-side.

Duke

[Drofo]

Hi Duke,

The 2x10 cab is actually a 4 ohm. Yes doubling it gets down to 2 ohms, but the amp can handle it.  I imagine making it 8 ohms would be a lot safer especially if you had no idea what would be driving it.

The 2x10 each has its own horn. That way if one is down you can still get top end off the other. Each also has it own attenuator for the HF.  That way you can set levels independently as well.

A single 12 sounds great. It would meet the needs of size and portability and would get good output. How small a box could you get a 12 into? How much top end can you get off a single 12. With guys now playing 6 and 8 strings, top end is more important than it used to be.

This is really funny, but I have totally separate thoughts processes when I think of audio and instrument amplification.  I actually don't combine the two. That said, forgive a possibly naive question, but when dealing with such low frequencies, why does polar dispersion matter. I would have thought that with such low frequencies (down to 26 - 29Hz on a 6 string) , it would make no difference.

Regards,

Drofo

[ooheadsoo]

I look forward to seeing what results from this inquiry.  I play a little bass but have no real experience picking out and tuning gear.

As for the polar dispersion, the woofers will play quite a bit higher than 26hz, I would imagine. 

I have heard some pretty awesome 4x10"+1"ers and wouldn't mind getting such a rig, myself, but with bass gear, price has always been a huge obstacle because, and I would like to think this applies to many of us, most of us do not play bass for a living nor play on a daily basis.  I play at church weekly and leave the kit there, so there is a high chance that little kids will abuse it.  Metal grills are definitely a good idea.  And yes, light weight would be really nice, or included casters, because moving it is no fun.  No roadies to help me out, you know...

[Duke]

Drofro, thanks for the additional information.  Very interesting.

You're right that the very deep bass is omnidirectional.  But, the mid and highs are not, and they're an important part of the timbre of the instrument.  A large cone will be quite beamy at high frequencies, even though its on-axis response may extend quite high.  Take a look at the second page at this link:

http://www.parts-express.com/pdf/264-334.pdf

Now at most normal listening distances the power response (summed omnidirectional response) dominates, so even though the on-axis response shows a distinct rise in the lower treble region the overall energy put out into the room up there is significantly down in level.  Still using this driver as an example, I'd be inclined to cross over to a wider-pattern driver (midrange or tweeter) above 2 kHz to preserve the upper harmonics.  I'd probably filter the woofer's output so that we don't get an on-axis "hot spot" up close, where that screaming peak at 3 kHz rips your head off.

So anyway it's not at the lower part of the spectrum that I'd worry about the radiation pattern - it's in the upper part.

Now maybe I'm being totally unrealistic here, but seems to me that most bass guitar cabs are optimized to give the loudest usable bass per dollar.  That's no doubt a worthy goal, but I wonder if, at a given price point, some bass players might trade off some quantity for a bit higher quality.  I'll probably have to build a prototype or two to find out. 

As ooheadsoo points out, light weight is definitely desirable in a bass cab for those who don't have roadies.  Unfortunately, adding a good mid/high frequency driver plus crossover can easily add 8 or 10 pounds and a couple hundred dollars in cost, so as in all things audio it becomes a juggling of compromises.

As a side note, light weight may become a desirable feature in a home audio speaker.  If the present economic downturn continues for a long time, it will squeeze brick-and-mortar high-end audio shops pretty hard.  With fewer places to demo speakers, shipping speakers for an in-home audition may play a larger role.  I probably picked the wrong type of speakers to manufacture for that situation - mine range from big to huge, and from heavy to you've gotta be kidding me. 

I appreciate you both participating here.  You're helping me out.

Duke

[Drofo]

Hey Duke,
Thanks for the info. I was unsure if lobing would still come into play on twin 10's with the addition of the HF driver.   I remember reading an article by Anthony Jackson, (one of the early proponents of  "quality" in bass amplification) who prized smooth roll off and wide dispersion in his speakers.

Yes ooheadsoo, I have also played on the 4 x 10. They are nice but they are larger, and include a HF driver too.  And with them you almost certainly have to have casters, adding to the cost. True, the metal grilles are not optional.

I realize that at some point you can't make a lightweight bass cab, that is affordable. You are right, drivers, are large and heavy. The cabinets have to be rigid and sturdy enough to take abuse, cause anytime you move something frequently, there's gonna be accidents. As you said the crossover adds weight. So yes you are not going to get it down beyond a certain weight, no matter what. I am sure that something could be done with carbon fibre, and aluminum, but who would pay for it   Really though, a 12" with HF driver would be pretty comparable to what's out there in weight. Probably on par with the 2 x10.

Ok, here's an idea, a single 12 cabinet, with a separate compression horn in its own stackable cabinet. You could use the cab and horn for stage/studio use, and if you needed more output, you could stack another 12 like an MTM arrangement.  They would all be reasonably sized, portable with decent weight. Would something like that work?

Drofo

[ooheadsoo]

Don't remind me about casters.  I play on a 70s era 15"+6.5" birch ply cab about the size of a 4x10, and my shoulders just sag whenever I even think about having to move it.  Even my 2x10+T is no fun to move.  Ok, maybe I'm just lazy.

Between durability, light weight, and affordability, it seems as if one must go for the other two to exist.   

Duke, what direction are you looking to take this project?  It wouldn't be healthy for me to have another bass gear to lust after, but what the hey.  Meanwhile, I'm still trying to save up enough for a decent bass guitar.

As for Drofo's idea, in that situation, I think it might be easier to produce a 12"+T and a 12" standalone rather than have the T in a separate enclosure.

I'm curious as to what kind of alignment the cabinet would have.

[DaveC113]

Hey Duke,
I am kind of old school and have to admit that i like the sound of the Ampeg SVT (8 x10") rig. However I have absolutely no desire to hump something like that around.  What i use is  a 2x10' plus horn in a small cab. I can stack another 2x10 if needed. That is a good combo of size output and portability.  Really for most venues, that is sufficient for stage volume.

While 10's can sound good, they don't have the same weight as a good 15". Maybe you could do a 2x10, plus HF driver plus a 15 in a separate cab. If stackable and roughly the same size, that would be versatile little unit. I am not sure if you could cross the 15" high enough to add a HF driver, but that would really increase the versatility.

Here is one time I would really be thrilled to see the Law broken. Hoffman's,  that is.

Regards,

Drofo

I completely agree. I have an Epifani 2x10 cab w/horn tweeter, which can easily stand on its own (and is an excellent reference btw)....  but an 18" woofer makes a good stand for the 2 x 10 and fills out the bottom nicely. They are bi-amped with an adjustable crossover, currently set around 100 Hz. The stack can make the whole house vibrate  aa   

Dave

[Duke]

One approach I'm considering is a two-piece system.

The main cabinet would have a 12" woofer with a very capable motor, so it can move a lot of air, but it wouldn't be super-efficient.   I'd aim for good reproduction of the first harmonic of both 4-string and 5-string bass.  Reproducing the lowest fundamentals (41 Hz and 31 Hz respectively) at full volume calls for a much bigger cab, and/or much lower efficiency, than I think is practical.  This cab would include a midrange driver that goes up to at least 6 kHz, along with a level control of some kind.  I could take it up higher than 6 kHz without too much trouble, if that would be worthwhile.

The other cab would house a 15" woofer with the same high quality motor as the 12" unit, but it would be about 3 dB more efficient (and predictably, this cabinet would be about twice as large).  So adding the 15" woofer would boost the maximum bass level by nearly 6 dB.  The midrange driver would be efficient enough that it could be adjusted to keep up when the 15" woofer is in use.  I'd try to keep the voicing the same whether or not the 15" cabinet was in play.

I hope to come in around 30 pounds for the small cabinet and 45 pounds for the big one.   Each cabinet would have an impedance of 8 ohms and could handle about 400 watts, both thermally and mechanically. 

The idea would be that you could take the small cab to practice and small gigs, and then bring along the big one when needed.   

Any thoughts?  Is this "different" enough from what's already out there to be worth a try?

Duke

[ooheadsoo]

30# sounds doable if the cabinet is small enough to carry easily by either 1 hand or two.  When moving both cabinets, it would be really nice if the two cabinets stack securely - and that they fit conveniently on a dolly if casters aren't involved.  Nice idea.

[Russell Dawkins]

I used to be a bass player - does that count?

I would like to see something a little more different, and I think if you want to catch the attention of the masses so you can become rich and retire with your Ongaku amps driving your Feastrex field coils while you sip your single malt, you need to catch the market's attention.

There is the market positioning thing, which I think is very important.

In the world of bass guitar speakers I think this might be done by marketing speakers where the value is in the drivers, not the cabinet - like the Emerald Physics CS2s. I'm thinking two cheap-but-good 15's in a shallow H-baffle - could even have folding side panels for compactness and driver protection. Variants would be 2 x 12 and 2 x 18. If I were a bass player doing smallish clubs now, I would be interested in an easily carried open baffle speaker. I can see it as having a handle on one side and being carried in the same manner as a bass guitar. I'm thinking something along the lines of Eminence Beta 15s or Goldwood 18s. Reports of the way these sound in an H baffle have really caught my attention of late.

The uniqueness of the market position would relate to the fact that, like the CS2, the "open-baffleness" would be made very apparent by the form factor (shallow, front to back) and in the promotion where it would, of course, be promoted as better than a box.

From what I've read (and admittedly I have read only one relevant account!) open baffle works really well with bass guitar, although what I read about was a larger array where the player arrived at a large venue with, I think, 4 or 6 - 15s on a baffle - no sides, just a panel. The sound man thought he was in for trouble, but when the player plugged in and played a few notes he realized this would not only work but it was about the best quality bass sound he had ever heard.

[jimdgoulding]

This has absolutely nothing to do with the topic, but if you, like me, think that bass guitar isn't well reproduced in most recordings, check out If Only I Could Remember My Name by David Crosby.  Jack Casady and Phil Lesh are on this and there is more tone and timbre to be heard from their instruments in this than I know of anywhere.  Well, there's a good bit in Hot Tuna.  There may be a problem for those of you w/o turntables- boy, this is getting more anticlimatic by the minute- cause THE way to hear this is on Classic Records.  Oh well, maybe somebody does.  Besides that, it's a great collaboration of exceptional players from the place (west coast) and time.  Not a throwaway track on it, IMO.

[DaveC113]

One approach I'm considering is a two-piece system.

The main cabinet would have a 12" woofer with a very capable motor, so it can move a lot of air, but it wouldn't be super-efficient.   I'd aim for good reproduction of the first harmonic of both 4-string and 5-string bass.  Reproducing the lowest fundamentals (41 Hz and 31 Hz respectively) at full volume calls for a much bigger cab, and/or much lower efficiency, than I think is practical.  This cab would include a midrange driver that goes up to at least 6 kHz, along with a level control of some kind.  I could take it up higher than 6 kHz without too much trouble, if that would be worthwhile.

The other cab would house a 15" woofer with the same high quality motor as the 12" unit, but it would be about 3 dB more efficient (and predictably, this cabinet would be about twice as large).  So adding the 15" woofer would boost the maximum bass level by nearly 6 dB.  The midrange driver would be efficient enough that it could be adjusted to keep up when the 15" woofer is in use.  I'd try to keep the voicing the same whether or not the 15" cabinet was in play.

I hope to come in around 30 pounds for the small cabinet and 45 pounds for the big one.   Each cabinet would have an impedance of 8 ohms and could handle about 400 watts, both thermally and mechanically. 

The idea would be that you could take the small cab to practice and small gigs, and then bring along the big one when needed.   

Any thoughts?  Is this "different" enough from what's already out there to be worth a try?

Duke

I'd consider 2 10s instead of a 12 and an 18 instead of a 15.... the 15/12 combo just won't hit the same volume or have the same impact.

[Duke]

Ooheadsoo, thanks for the encouragement.  At this point I've run into a couple of hurdles on enclosure cost, so may have to rethink a bit.

Russell, I did some modelling of dipole bass systems and to keep up with a drum kit looks to me like we'd need an awful lot of woofers.   You mentioned the Eminence Beta 15 - we'd need about eight to rival the bass region SPL that one could give us in a good a vented box.  

That being said, maybe there's a window of opportunity for a dipole guitar speaker.  Open-backed guitar cabs are a type of dipole, for that matter - perhaps there's room for improvement there.  As usual, the challenge will be doing justice to the lower end of the instrument's spectrum. 

Jim, thanks for the recording recommendation!  I used to have "If Only"; loved the song "Orleans".  Looks like it's time to get another copy.

Dave, the drivers I have in mind have exceptional excursion capability.  The 12 can move more air than any pair of bass guitar 10's I know of and more than most 15's, and the 15 can move more air than most 18's.  The limiting factor in bass cabs is almost always displacement rather than thermal power handling, but in this case the woofers will run into their thermal and mechanical limits at just about the same time - so this is a more efficient use of their available capabilities.

[DaveC113]

Dave, the drivers I have in mind have exceptional excursion capability.  The 12 can move more air than any pair of bass guitar 10's I know of and more than most 15's, and the 15 can move more air than most 18's.  The limiting factor in bass cabs is almost always displacement rather than thermal power handling, but in this case the woofers will run into their thermal and mechanical limits at just about the same time - so this is a more efficient use of their available capabilities.

Sounds like a very large amp will be required... 

[Duke]

Time for an update on the bass guitar cab project.

I ran a poll over on TalkBass.com inquiring as to whether a modular cab system, or a superior tonal quality system, would be of greater interest to bass players.  The weight of opinion, and the stronger arguments (or so it seemed to me), were on the side of pursuing tonal quality.

So I have decided to set aside the modular idea for now at least, and focus on creating a cab with a distinctive, superior sound quality.  I think this is where I can most distinguish myself from the competition (assuming my stuff gets "out there" and is actually heard).  For right now I'm keeping the details of how I plan to do this under my hat, but there will be something going on in the midrange region that I don't think has been done before in this context.  In the bass region, well, there's not much that hasn't already been done with a reflex bass cab, so until Hoffman's iron law is repealed there's not nearly as much opportunity there as in the midrange region.

[Russell Dawkins]

Verily, I think that the best tone quality, even for a bass cab, is no tone quality - no tone.

In the same way the ideal home speaker has no character, so the character of the music (or recording) can shine through, I think this is an unrealized ideal in instrument speakers.

Accordingly, I'll bet a truly useful and surprising innovation in bass cabs would be for it to have less personality, for maximum expressiveness. When you shut up, it should shut up. The fall time should be as fast as the rise time.

Fortunately, this ties in with the cheaper-than-ever power available these days, because I think the solution lies in sealed cabinets and contoured signals. The box could be smaller, too, and that's a bonus that wouldn't be hard to sell. Back to back drivers are another  solution (like the Barefoot Monitors).

I think I've finally pretty well had it with ported speakers of any kind, including transmission lines, now. It's the resonance I don't like. Once you've heard a speaker that doesn't hum along with the music, there's no going back.

In the past I have enjoyed a few speakers' bass where the box turned out to have a resistive port, like most of the cheaper Fried designs (Irving had a gift, in my eyes) and the evergreen Dynaco A25.

[JP78]

2x18's in open baffle / dipole, with the folded sides holding multiple 5" midrange cones? this could all fit in a 25x45x10 inch space, which would all fit within almost any car trunk or backseat.  also, the amp would fit nicely to bolt on if it were 19" rackmount style. well, just a thought, but i'm all for novelty with innovation instead of just typical innovation .

[Duke]

Hi Russell,

I definitely agree with you that the best tone is no tone - let the instrument, not the cabinet, do the talking.  This paradigm is one of my secret weapons.  However, "no tone" is not part of the language that's spoken on TalkBass.  So that's what I'm going to give them, but I'll have to call it something else. 

I considered doing a sealed box, but there's a serious shortage of prosound woofers suitable for sealed box operation.  And those few that I'm aware of have poor midrange performance. 

Have you ever heard a good low-tuned vented system?  A properly designed low-tuned vented system can emulate the rolloff of a low-Q sealed box over about two octaves.   They sound very tight and fast, not unlike a resistive port system (which might be, in effect, similar to a low-tuned vent; I'm not sure how to analyze it).  Anyway by using a modular port system, the owner can choose between tight bass and a "fatter" sound, depending on the gig.

JP78, I do like the way a good dipole bass system sounds but I think it's impractical for a bass cab.  Even with two 18's on a big baffle, after equalizing for the losses from dipole cancellation we'd probably have less output than a typical 2x10.   There may well be a market for the system you describe, but it will take someone with more... ah... optimism than yours truly to attempt it!