alexclaber
Commercial User
Fortunately not! Entirely different kind of system although the F-holes in a 'Cello are also Helmholtz resonators.
Enjoy the benefits of a premium membership!
Upgrade Account
-
TalkBass has been independent since 1998. Add your voice.
Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
Join free Log in
Want zero display ads or expanded classifieds tools? Compare plans.
Acme Full Range Series III 112
- Thread starter KJung
- Start date
Fortunately not! Entirely different kind of system although the F-holes in a 'Cello are also Helmholtz resonators.
Something to remember about the Acme is that he did tailor the top end of the modified 3012LF to be pleasant to the ear. IMHO, you'd be better off with a stock 3012LF, a higher tuning, and some kind of passive filter (say like GB's standard 12sub crossover), if you wanted to achieve Flatwound-like profile.
GB, what kind of top end would a 12Sub have with the standard low pass you use? Would it be similar to the Flatwound, or a bit lower?
GB, what kind of top end would a 12Sub have with the standard low pass you use? Would it be similar to the Flatwound, or a bit lower?
Wait a minute. If Andy "tailor[ed] the top end of the modified 3012LF" to build the actual Flatwound, why would anyone be "better off with a stock 3012LF, a higher tuning, and some kind of passive filter (say like GB's standard 12sub crossover), if you wanted to achieve Flatwound-like profile" !?
- Dec 18, 2000
- 13,201
- 340
- Disclosures
- greenboy designs: fEARful, bassic, dually, crazy88 etc
I'm not making any sense out of that either.
But somewhat related, the 3012LF actually sounds pretty good throughout its range, as is - unlike some full-scale subwoofer drivers or longer-xmax choices.
But somewhat related, the 3012LF actually sounds pretty good throughout its range, as is - unlike some full-scale subwoofer drivers or longer-xmax choices.
It's two (maybe three) separate thoughts I guess I should have paragraphed up.
1. That Andy didn't just sacrifice a 3012LF's sensitivity for more lows and drop it in a box, he also tweaked parameters to get a nicer top end. So the discussion is a tiny bit more complicated than just comparing low end profiles.
2. That you could just use a 3012LF and do a little tone shaping up top and achieve a very similar result without making that huge sensitivity sacrifice.
--and then asking how the 12Sub would sound on its own - is the low pass section there high enough to sound pretty good on its own?
1. That Andy didn't just sacrifice a 3012LF's sensitivity for more lows and drop it in a box, he also tweaked parameters to get a nicer top end. So the discussion is a tiny bit more complicated than just comparing low end profiles.
2. That you could just use a 3012LF and do a little tone shaping up top and achieve a very similar result without making that huge sensitivity sacrifice.
--and then asking how the 12Sub would sound on its own - is the low pass section there high enough to sound pretty good on its own?
alexclaber
Commercial User
My points were nothing to do with mid/high design goals, they were regarding T/S spec targets, cab size and tuning and the resulting bass response. The 3012LF sounds fine fullrange, if limited in treble extension - far less spiky on top than many popular bass guitar woofers. We put one in a Midget T by accident once and it sounded really rather nice despite the 1/2 octave gap between woofer rolling off and tweeter kicking in. You could easily have an OEM version tweaked to go a bit higher as with the two Acme 12"s but the high inductance is always going to limit the treble extension more than with shorter voice coil woofers.
Most of you are aware that Andy doesn't regularly participate (never?) in TalkBass forum discussions, but I thought this one would interest him and sent it over. To my surprise, he provided this response and authorized me to post it:
Duke and Greenboy are essentially right-on. I have a little bit of a problem with Duke's explanation of the Helmholtz resonator, because of the similarity of a bottle to a tuned pipe, which resonates as a wave device, not a pressure device, as does a true Helmholtz resonator, but in fairness, the HR is VERY difficult to explain, and is counter-intuitive. Walt Hyde reinterpreted my explanation, and explained it better in an email than I was able to on my site, and I share his words:
"Likewise when you said that the port output is in phase with the cone's output, a light went on in my head. You've been saying all along that a speaker is a pressure device, and not a wave device. So I started thinking about it... we usually think of it as as wave device, with the woofer going out and sucking air into the port, and the woofer going in and pushing air back out of the port. Out of phase, even, Maybe this is true at infrasonic frequencies. But if the speaker is a pressure device - a Helmholtz resonator - then the static air mass inside will be expanding and contracting in the same direction from both the cone and the port. The woofer serves as an excitation to compress and rarify the air mass. At resonance, the mass-spring model of the air, well, resonates at its natural frequency, and the woofer doesn't have to work very hard to introduce energy into the system to overcome the Q losses. But on either side of the resonant frequency, the woofer moves more, and the phase drifts away from zero to some degree. Loudspeaker as a pressure device - now it makes sense!"
I believe all of the questions about port tuning, and box volume, as relates to response can be answered using my "Evaluate Woofer Sealed or Vented" spreadsheet in the Speaker Design section of my site. I'm not aware of anybody presenting the work of Small in such an intuitively obvious fashion, which is why I did it, and it should be helpful to some of the questioners. I don't get into port area versus length, but I think Duke and Greenboy do a good job with that. I'd like to know what software Greenboy is using to make those pretty graphs.
Sometimes these issues can be understood better if you remember that the enclosure is part of an acoustic circuit. The air volume is a capacitor, and the port is an inductor. The loudspeaker system as an acoustic circuit is the essense of what Small taught us, and just as with an electrical circuit, the capacitance and the inductance can be manupulated to realize a targeted response.
My friend Alex does a good job of explaining some stuff too, but the idea that port tuning has no effect at low volume levels is not quite right. An inductor's inductive reactance is independent of voltage, and a port's acoustic reactance is unrelated to volume level. I would also clarify about the 31 Hz tuning. Power handling decreases rapidly, and response rolls off at 24 db/octave below the enclosure's tuning frequency. To maintain power handling down to "B," it's necessary to tune the system to that frequency, or at least close to it. It then becomes necessary to design a woofer which is optimized to work with that tuning, in a real-world enclosure. That's what both my 10" models and my 12" models are about. The unfortunate fact is that if you tune an enclosure much higher than 31 Hz, and pound it with a "B" note for long, you will destroy the driver. The other option is to use a sealed enclosure, which maintains power handling essentially to DC. This would be the SVT.
Your faithful messenger,
Duke and Greenboy are essentially right-on. I have a little bit of a problem with Duke's explanation of the Helmholtz resonator, because of the similarity of a bottle to a tuned pipe, which resonates as a wave device, not a pressure device, as does a true Helmholtz resonator, but in fairness, the HR is VERY difficult to explain, and is counter-intuitive. Walt Hyde reinterpreted my explanation, and explained it better in an email than I was able to on my site, and I share his words:
"Likewise when you said that the port output is in phase with the cone's output, a light went on in my head. You've been saying all along that a speaker is a pressure device, and not a wave device. So I started thinking about it... we usually think of it as as wave device, with the woofer going out and sucking air into the port, and the woofer going in and pushing air back out of the port. Out of phase, even, Maybe this is true at infrasonic frequencies. But if the speaker is a pressure device - a Helmholtz resonator - then the static air mass inside will be expanding and contracting in the same direction from both the cone and the port. The woofer serves as an excitation to compress and rarify the air mass. At resonance, the mass-spring model of the air, well, resonates at its natural frequency, and the woofer doesn't have to work very hard to introduce energy into the system to overcome the Q losses. But on either side of the resonant frequency, the woofer moves more, and the phase drifts away from zero to some degree. Loudspeaker as a pressure device - now it makes sense!"
I believe all of the questions about port tuning, and box volume, as relates to response can be answered using my "Evaluate Woofer Sealed or Vented" spreadsheet in the Speaker Design section of my site. I'm not aware of anybody presenting the work of Small in such an intuitively obvious fashion, which is why I did it, and it should be helpful to some of the questioners. I don't get into port area versus length, but I think Duke and Greenboy do a good job with that. I'd like to know what software Greenboy is using to make those pretty graphs.
Sometimes these issues can be understood better if you remember that the enclosure is part of an acoustic circuit. The air volume is a capacitor, and the port is an inductor. The loudspeaker system as an acoustic circuit is the essense of what Small taught us, and just as with an electrical circuit, the capacitance and the inductance can be manupulated to realize a targeted response.
My friend Alex does a good job of explaining some stuff too, but the idea that port tuning has no effect at low volume levels is not quite right. An inductor's inductive reactance is independent of voltage, and a port's acoustic reactance is unrelated to volume level. I would also clarify about the 31 Hz tuning. Power handling decreases rapidly, and response rolls off at 24 db/octave below the enclosure's tuning frequency. To maintain power handling down to "B," it's necessary to tune the system to that frequency, or at least close to it. It then becomes necessary to design a woofer which is optimized to work with that tuning, in a real-world enclosure. That's what both my 10" models and my 12" models are about. The unfortunate fact is that if you tune an enclosure much higher than 31 Hz, and pound it with a "B" note for long, you will destroy the driver. The other option is to use a sealed enclosure, which maintains power handling essentially to DC. This would be the SVT.
Your faithful messenger,
- Dec 18, 2000
- 13,201
- 340
- Disclosures
- greenboy designs: fEARful, bassic, dually, crazy88 etc
Always a couple ways to think about it. You can even model this woofer in a box stuff in a Spice application, as LCR, if you are masochistic. Parallels are drawn between springs and mass and LCR circuits in some quarters.
alexclaber
Commercial User
I think there was some misreading there! I said port area is irrelevant at low levels, not port tuning. Everything I was talking about was about the importance of port tuning decisions.
As I've said before I strongly disagree with the "tune to lowest note fundamental" approach. Real world usage has repeatedly shown that the old Acme cabs which follow this principle suffer far more worn out and blown woofers due to overexcursion than similarly high excursion cabs with less extremely low tunings. Actual energy content of low bass guitar notes and frequency response of amplifiers should be considered - just thinking about 31Hz sine wave behaviour is overly simplistic. Such low port tuning can result in great sounding, if relatively quiet, cabs but it actually makes life harder for a woofer when you're thumping out high volume low
Bs than if the cab was designed around a higher tuning frequency. Hundreds of well gigged Barefaced cabs out there confirm this with two blown woofers out of the entire lot (both thermal not over-excursion failures with a ~1000W heavyweight amp into a 450W 15").
But as I've also said we continue to disagree on that design decision!
Yeah IIRC from GB's waterfall plots, something like twice the energy is at the 1st overtone (62hz) when playing a low B (...or it might be better to say the fundamental has half the energy as the next overtone). Correct me if I'm wrong. I just remember the discussion was about why the 1st overtone was more important.
- Dec 18, 2000
- 13,201
- 340
- Disclosures
- greenboy designs: fEARful, bassic, dually, crazy88 etc
Yeah, sometimes more than that yet. The first 4 overtones are the biggies.
Another thing that was covered is how little sensitivity the ear has to the lowest content until the SPL level is way way up there, and how people can actually not audibly perceive content down there as especially pitch-based when it is stripped of all-speaker generated harmonic distortion or upper content. Content down there generally exists to tell you to run from the volcano (yes, you can feel it), or to show off your blueray theater.
But that doesn't mean the Acmes don't have girth. That's more a function of tonal balance. If you have a lot of sub-100 hz content relative to the +100 Hz content it's going to sound big and deep. That's one of the tricks of EQing in fact - to change the relative balance of various regions by cutting, to highlight other ones. And vice versa.
Another thing that was covered is how little sensitivity the ear has to the lowest content until the SPL level is way way up there, and how people can actually not audibly perceive content down there as especially pitch-based when it is stripped of all-speaker generated harmonic distortion or upper content. Content down there generally exists to tell you to run from the volcano (yes, you can feel it), or to show off your blueray theater.
But that doesn't mean the Acmes don't have girth. That's more a function of tonal balance. If you have a lot of sub-100 hz content relative to the +100 Hz content it's going to sound big and deep. That's one of the tricks of EQing in fact - to change the relative balance of various regions by cutting, to highlight other ones. And vice versa.
Cool... Not often that you get Alex, Andy, Duke, and Greenboy in the same thread.
Reluctant to interrupt with something so basic, but I'd like to contribute on the matter of Helmholtz resonance; something I think many people (not these guys, obviously) have trouble conceptualizing. An analogy I like for describing HR is that of a paddle ball.
The ball has a natural frequency at which it will go up and down, determined by the mass of the ball, and the stiffness of the rubber band.
Translating this model to a ported speaker cabinet, the speaker cone is the paddle, the air mass contained in the port is the ball, and the air in the cabinet is the rubber band.
This model is imperfect, but hopefully, is intuitive for anyone who has played with a paddle ball.
Reluctant to interrupt with something so basic, but I'd like to contribute on the matter of Helmholtz resonance; something I think many people (not these guys, obviously) have trouble conceptualizing. An analogy I like for describing HR is that of a paddle ball.
The ball has a natural frequency at which it will go up and down, determined by the mass of the ball, and the stiffness of the rubber band.
Translating this model to a ported speaker cabinet, the speaker cone is the paddle, the air mass contained in the port is the ball, and the air in the cabinet is the rubber band.
- Adding length to the port (like making the ball heavier) lowers frequency.
- Making the cabinet smaller (like making the rubber band shorter) raises frequency.
- The air in the port is only excited into resonance when the speaker cone (like the paddle) is moving at it's natural frequency.
This model is imperfect, but hopefully, is intuitive for anyone who has played with a paddle ball.
Jazzdogg
Less barking, more wagging!
I love effortless deep bass with 5-string electric, and the bottom provided by the Acme calls out to me like a siren near a rocky shoal. But my goal is 2 cabs that can double. How are Acme 12s with DB?
I keep coming back to a small sub, like the Danley TH mini or JTR Growler, and a Thunderchild; TC alone for DB, add the SUB for 5-string electric.
I think there was some misreading there! I said port area is irrelevant at low levels, not port tuning. Everything I was talking about was about the importance of port tuning decisions.
As I've said before I strongly disagree with the "tune to lowest note fundamental" approach. Real world usage has repeatedly shown that the old Acme cabs which follow this principle suffer far more worn out and blown woofers due to overexcursion than similarly high excursion cabs with less extremely low tunings. Actual energy content of low bass guitar notes and frequency response of amplifiers should be considered - just thinking about 31Hz sine wave behaviour is overly simplistic. Such low port tuning can result in great sounding, if relatively quiet, cabs but it actually makes life harder for a woofer when you're thumping out high volume low
Bs than if the cab was designed around a higher tuning frequency. Hundreds of well gigged Barefaced cabs out there confirm this with two blown woofers out of the entire lot (both thermal not over-excursion failures with a ~1000W heavyweight amp into a 450W 15").
But as I've also said we continue to disagree on that design decision!
While much of what Andy posted was over my head, I have to agree with you here (I remember having many discussions with you about this as you were moving from your Acme B210's to using cabs of your own design).
When Andy says that playing the lower B string notes can 'damage' regular speakers, that obviously doesn't ring true, since as you say, the original Acme's were much more likely to be damaged than a little Guitar Center 110 cab.
Since Andy is not an idiot
, I'm assuming what he means is that EQing so that the fundamental frequencies of the lower notes on the B string comes cranking through a 'typical cab' can be a bad thing, and I think we've all experienced that.Where the disagreement comes in is how much of the true fundamental is actually needed to provide a 'good sounding' low end from an extended range bass. For all of us who have gigged Eden 410XLT's, the answer is clearly 'not much'.
So, IMO, this seems to be more of just a design decision for me. I am actually just as impressed with the girth and fatness of the notes on the A and E strings with the Acme12 as with the full fundamental wump of the lower notes of the B string. It is just a fat sounding cab, and you pay the price in efficiency. Makes sense to me, and given the nice light weight of the Acme 12's, using two of them with an amp with enough power to make them sing is a pretty viable option for those who are looking for this particular tone profile. And, to be clear, a single 4ohm Acme112 Fullrange or Flatwound with a wump of power into it from an amp designed with a big but controlled low end like the Genz Streamliner can result in this cab being signficantly louder than the typical 'commercial 112'. Just to make that clear again, I was playing with a relatively loud band in a relatively large room with a single 12, and the low notes all the way down to the open B were full and loud. You aren't going to get there with a Markbass or GK cab or whatever... no way. So, we shouldn't overstate the efficiency thing too much when talking about a single 112!
I continue to dig the cab a lot, and there is something about that 'fat' tone profile that results in not really needing that typical higher efficiency in the midrange that most cabs exhibit, at least for some playing contexts. That all being said, playing the Acme also makes me realize how well Duke reached the almost perfect compromise for the gigging freelance 'big city' bassist... smaller size than many production 112's, 4ohm impedance for optimal use with micro's, a low end that is tuned as a 'perfect compromise' of more full low end than almost any production 112, but the mechanical ability to pump that sound out at surprisingly high volumes, and an almost 'studio monitor' midrange response that is extended but natural. Quite amazing.
Again, really nice job Andy did on this cab, and IMO it is a significant improvement (for me anyway) from the original B series boxes in tone, performance and weight.
That being said, DEFINITELY a different voicing and performance that will be IMO disliked more than liked by the general bass community.... almost the definition of a niche product for me. I would think, rom Andy's comments on his website, he would agree with this. The cabs 'are what they are'.
Honest question here: Is this generally because of the design, or is it user error? I ask because when these cabs hit the market, they were among the least efficient designs out there, and "common knowledge" was that you needed to throw a lot of power at them. It seemed to me at the time that people were driving them with very high-powered power amps in bridge mode, and a lot of people likely didn't heed the fact that they were playing through a single 2x10 cab.
I guess I shouldn't have said user error...the Acme literature does imply that you can and should use a lot of watts.
PS- I'm moving to the UK early next year, and hoping to look into Barefaced cabs when I do. If logistics permit, maybe I can get my Flatwound across the Atlantic and we can do some live shootouts.
I like reading these threads about the new design bass cabs, but, it seems like most of the players are 5 string guys, commenting on how well the B string rings out. Having played neither one of these cabs, I would guess that, for a guy like me, who plays the kind of gigs that Ken plays ( pop, rock, motown, dance floor faves), that the Thunderchild would be the way to go for a 4 stringer. It seems to me, from comments I have read, that it covers more musical genres better than most, especially the Acme . OTOH, if I was in a classic Motown band, I might go for the Acme. But, would you guys say, in general, that these cabs are a little overkill for the 4 string player ? I don't mean that in a negative way, btw.
IMO, I don't believe these cabs are overkill for anything. I play 4-, 5- and 6-string, and am currently in a progressive rock band, a 70s-90s rock cover band, a hip-hop funk band and a jazz/folk band, and my Acmes sound great in those contexts, with all of my basses including upright. I think there is a propensity to pigeon-hole them into a "5-string only" cab, or a "P-bass-with-flats" cab, but I'm neither of those players and both work great for me, in practice and on stage.
I think Ken has done a nice job of cataloging the differences between the Acme and the TC, so what I got from his comparison is; if max spl and dispersion (at the expense of a little low-end) are your priorities then the TC is best for your preferences. If you want the ability to go lower (meaning "meatier down low", not just B-string reproduction), at the expense of some efficiency and dispersion, go Acme.
YMMV.
+1. I believe Ken has mentioned once or twice that the Acme is not just B-string cab, it adds meat across the board. I personally think it's a great classic rock, R&B, and jazz cab.
Since I'm doing a good bit of doubling between my Lakland 55-94 and Double Bass these days, the Thunderchild is my go to cabinet for most gigs. It's just the ideal cabinet for 4 string or 5 string. Sometime when Ken gets to St. Louis, he and I can compare the two with my 59 P Bass and my Mirecourt Double Bass.
I haven't been on any gigs where the Thunderchild would have been overkill. It a relatively small box with a beautiful sound. So far, I've never used the port plugs, but there available if I need them.
Ric
alexclaber
Commercial User
Acme cabs were what introduced me to proper bottom from a bass rig - and I used them very happily for almost a decade until I designed and built my own and the whole Barefaced thing started. I remember being constantly surprised when I heard other 'boutique' cabs and wondered where all the bottom was! And that was with 4-string mostly. With the Barefaced Big Series cabs I was determined to keep that bottom end but without such a compromise at high SPL - I really really like deep lows and done properly they are no downsides to them.
Regarding 'user error' with the Acmes, it's certainly not design error - they're really well designed for their end goal. But when you're playing rock 'n roll (and anything that's spun off in the past sixty years) things often get a bit too loud and silly and things go wrong. I prefer to make stuff all but unblowable because I hate the idea of a bassist not taking his amazing sounding rig to a gig with shared backline because he's scared of a clueless newbie toasting it.
Regarding 'user error' with the Acmes, it's certainly not design error - they're really well designed for their end goal. But when you're playing rock 'n roll (and anything that's spun off in the past sixty years) things often get a bit too loud and silly and things go wrong. I prefer to make stuff all but unblowable because I hate the idea of a bassist not taking his amazing sounding rig to a gig with shared backline because he's scared of a clueless newbie toasting it.
