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Acme Low B-2 - This is how power hungry!

Discussion in 'Amps and Cabs [BG]' started by Jim C, Apr 14, 2009.

  1. Jim C

    Jim C Is that what you meant to play or is this jazz? Supporting Member

    Nov 29, 2008
    Bethesda, MD
    So, my original post asked the question would this cab be good with an SVT 3Pro; I passed on the unit that was for sale as many thought it wouldn't have enough power.


    Just received this from Andy:

    Hi Jim,
    Thanks for the inquiry.

    In fact, the SVT Pro3 is an amp I recommend to users of our 2x10, just because our customers love the combination. I have no personal experience with the amp, I only know what I'm told.

    The 2x10 will hold its own up to the point where light drum miking is used, as in snare and kick. If your band is loud enough so the full drum kit must be miked up, you will probably need a larger rig, or a little PA support yourself.

    Andy Lewis
    Acme Sound Ltd

    arrghh; maybe should have bought that cab as most rave about the tone; down side being power hungry :crying:
  2. Zooberwerx

    Zooberwerx Gold Supporting Member

    Dec 21, 2002
    Virginia Beach, VA
    Doesn't the SVT do 275 watts @ 8 ohm, 450 @ 4 ohm?

    Andy recommends it based on the subjective testimonials of others so take it with a grain of salt. On a more positive note, I see B-2's pop up on TB, E-bay, etc.....keep your eyes peeled.

  3. Rick Auricchio

    Rick Auricchio Registered Bass Offender

    +1. Everybody has his own idea of loudness.

    For example, I sub occasionally with an "outlaw rock" (country-flavor) band. Electric guitar, acoustic guitar, drums, bass. All but the drummer sing.

    I'll do those gigs with the Eden WTX-260 and one D112XLT.

    Now, someone else's drummer might be much louder...
  4. Jefenator

    Jefenator Supporting Member

    Aug 22, 2008

    Some people love their B-2 with 450 watts or even less.

    All I know is, my B-2 was always clipping the Stewart World 1.2 power amp (one side @ 450).

    I did indeed get some heavenly tone moments. But for my application, I'm glad to now have a bit more speaker area for heft & a bit more efficiency plus a slight low-mid bump to give the poor power amp a break.

    I'll let you know if I ever sell the GS212! ;)
  5. greenboy


    Dec 18, 2000
    remote mountain cabin Montana
    greenboy designs: fEARful, bassic, dually, crazy88 etc
    And I've journalled here at least a couple times how weak that amp is when dealing with demanding jobs. And seen over the course of ten years many others who have experienced that too. I'm sure someone somewhere hasn't had problems when really putting those to the full monty but sure enough folk have.

    So it's probably the last or one of the last amps in the world I'd use with an Acme, regardless of wattage class.
  6. KJung

    KJung Supporting Member

    IMO, you did well on passing on the SVTIIIpro. IMO, that head is at the very low end of current ss/hybrid offerings regarding the price/weight/quality/power/features continuum.

    Also, IMO Andy's comment on volume is a gross oversimplification, since individual drum volume (e.g., Billy Cobham playing full out is a very different thing from Brian Blade, etc.) and also the particular playing context (mutliple guitars, singers, etc.) can have a huge impact on volume requirements, especially with the very wide, pure, deep voicing of the Acme cabs.
  7. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    Jim Y' blew it and you still have the impression that Acmes are power hungry. That's sad that! If an Ampeg, just as an example, is rated at 400W would you call it power hungry? How it it that an Acme B2 rated at 350W is power hungry? The only difference is that Acme CAN handle more if you are so inclined.

    I posted that given 350W each a pair is as loud as I could ever need. Do I have to use that much - of course I don't. I doubt whether I'm using 2-300W total when I am at my very loudest. My only caveat was that I didn't think that one 2x10 is enough to gig with regularly. That applies to any 2x10 you choose.

  8. KJung

    KJung Supporting Member

    I know this is an old discussion, but just to make sure people don't go down the wrong hole on this. The power 'rating' of a cab is relatively useless information, and has nothing to do with SPL that we are talking about here.

    Also, there is no such thing as 'SPL of a cab', only SPL at a given frequency (with the published SPL being typically at 1K). As most know, the issue with the Acme's is that the SPL frequency curve is more even than with many production cabs out there (I believe this is Andy's primary selling point). What does this mean in my 'layman's understanding' of SPL curves? Well, it means that the Acme's actually have HIGHER SPL in the very low frequencies where many cabs roll off.

    As a result of the higher deep low end SPL (which I believe is a result of the cab tuning resulting in the impedance of the Acme cabs at those very low fequencies being quite a bit lower than many other cabs... that's another point, there really isn't such a thing as 'cabinet impedance' either, just nominal impedance, which I guess is kind of an 'average impedance' when considering the entire range of the cab), the Acme cabs need more power to deliver an overall level of volume versus other cabs. This is because low end frequencies take more power than higher frequencies to hit the same SPL.

    So, the Acme's can take quite a bit more power to reach the same 'overall SPL" since they put out so much 'power intensive' low end relative to other cabs. This is a good thing for many.

    Illustrating this is very easy. Hook up your amp to an Acme cab (let's just say an 8ohm B2 for this example). Set your amp so that it sounds good to you, and turn it up so that it is relatively loud. Now, without changing any settings, turn off the amp and unplug the Acme and plug in, for example a Bag End SD15 (or another more tightly voiced, higher 'published SPL' cab). The difference in perceived volume will literally be shocking. Of course, that's because, in this case the Bag End is rolling off way higher than the Acme, and cranking the mids which sound brutally loud to our ears.

    Finally, the reason some of us don't like the Acme's in certain mixes is that the RATIO of mids to low end is quite different than most cabs, and in many rooms, it's amazing how much upper mid and treble you have to wump through a mix to get an even, wide, pure tone with as much volume about 1K as below 100hz, given the people, carpet, drapes, etc. absorbing that upper frequency response, and also the drums and guitar masking those frequencies. I believe this is why many cab companies 'pre tune' their cabs a bit to take this into account (i.e., for the cab to sound a bit more even 'in a typical room' versus in an isolated sound chamber on a scope). Of course, if you are one who likes an old school 2 x 115 tone, then the 'above 1K issue' I mention is a moot point:).

    IMO, and based on a layman's understanding of the EE issues that I've learned on this site. Maybe my buddy TBer 'Kindness' can fix any (or all!) inaccuracies. Assuming the above is relatively correct, the whole 'Acme power thing relative to perceived volume' makes total sense to me.
    Snaxster likes this.
  9. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    It's simply the lower sensitivity in the midrange that makes Acme cabs quieter - but that's as a result of the cabs being designed to go low. They can handle a lot more power in the true lows than other similar sized cabs, so for those that like a deep fat sound and have enough power an Acme 2x10" will be louder than any other 2x10". For those that are more into midrange punch and growl they may find that other cabs go as loud or louder with less power.

    I found in direct A/B testing that without changing the knob positions a 4 ohm B2 was marginally louder in the midrange and highs than an 8 ohm UL112 but had significantly thicker fatter deeper bottom. And it can handle the amp being turned up quite a lot more.

    Strangely enough Acme cabs don't tend to draw more power in the lows, they actually draw less because the speaker, cab and port are designed to encourage more resonance and thus greater low frequency efficiency. But some amps do cop out with Acmes because although they may be rated at 400W (like some of the old Eden heads) they don't have the power supply or cooling to sustain that output, and the lower sensitivity of the Acme demands more power input for a given SPL output.

    Sadly although watts are watts there's a lot of leeway in how they are specified!

    Snaxster likes this.
  10. KJung

    KJung Supporting Member

    Ah, thanks for the clarification on the power draw. (Edit: However, this still can be a bit misleading. Yes, the Acme's are more efficient WAY down low than other speakers. However, as you point out, that still takes a lot of power, hence my point on needing more power, and your point on some amps not being able to deliver that power). I agree, if you try to pump a ton of low deep low end into a cab that is -10db down there, it will be 'less efficient' than the Acme. The key is, do you want those low frequencies in your tone (i.e., the classic 'polite mids/deep low end' of the Acme voicing. It's neither inherently better or worse than other voicings, but it sure is different.

    Regarding your 4ohm B2 comparison with a small and relatively deeply voiced 8ohm 112, that doesn't surprise me, and is a bit different than the comparisons we made at GTG's, etc.

    Quick question, I got that 'lower impedance' thing from the EA site, which talks about how the transmission line design results in more low end by lowering the impedance of the cab in the low fequencies, hence letting more power being delivered at lower frequencies. Is that correct, and if so, is that specific to a transmission line design, or is it just marketing hooey!:D

    Also, given the three way design, there should be no reason for lower sensitivity in the midrange with the Acme (Andy's whole deal of the little midrange driver 'allowing' him to design a speaker with a woofer and tuning that can go LOW). That's a design flaw I assume due to using too small or too low SPL or whatever of a midrange driver, correct?
  11. bassbrock


    Feb 20, 2007
    Callahan, FL
    My current rig at the moment is an G&L L2500 -> Zoom B2.1U -> Aguilar Tone Hammer -> Behringer EP2500 Power Amp Bridged @ 4 ohms (2400W) into a pair of Acme Low B4 8 ohm cabs in parallel. I have all the volume and tonal variety I could want at the moment. :)
  12. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    I haven't spent much time on transmission line (or quarter wave) designs so will have to get back to you on that one. Bass tuning is all about altering the impedance curve by altering the resonant characteristics of the system so I wouldn't discount their explanation.

    The midrange driver only takes over from about 1kHz so if it was much louder then it would sound too harsh/honky compared to the woofer. If the woofer was higher sensitivity (like in my Barefaced cab with the midrange driver) then you would have to use a higher sensitivity midrange speaker. I'm loving the combination of relatively high sensitivity and huge power handling with the Big One, its tone remains so consistent however loud you go.

  13. Jefenator

    Jefenator Supporting Member

    Aug 22, 2008
    I guess I just still have doubts as to whether the Ampeg in question (SVT3Pro) would be appreciably better than what I was using at first to power my B-2.

    I like and trust Andy, but I still don't know exactly how many satisfied 3Pro/B-2 customers he is referring to and what kind of situations they use their rigs for.

    I have read a few accounts, all of which seemed credible to me, that the SVT3Pro's power section can be lacking. If some users are unsatisfied with the power, probably using conventional speakers, going the Acme route is definitely going to exacerbate that IMO.

    Some people love their SVT3Pros - apparently even with Acme - so obviously it works fine for some applications.

    But if there's any doubt as to the conservativeness of a 450 watts rating... and if you're trying to milk a certain degree of performance from a cab for a certain setting (in OP's case, moderately loud funk band w/ TWO guitars + keys)... my experiences cause me to remain skeptical.
  14. KJung

    KJung Supporting Member

    Cool. That makes sense, and that lack of midrange sensitivity is, I guess, why my B2's ended up not working very well for me.
  15. jerry

    jerry Doesn't know BDO Gold Supporting Member

    Dec 13, 1999
    My real-time experience with a Acme B2 and SVT3 pro was they were not a great match. IMHO and all that.
  16. greenboy


    Dec 18, 2000
    remote mountain cabin Montana
    greenboy designs: fEARful, bassic, dually, crazy88 etc
    Pretty much all's been covered here. As far as what an Acme is capable of, if you are playing in a mix where it's not about cutting through so much as it is floating the rest of the band on a swell of richness with detail, if without PA support - and/or you like hearing that depth and warmth and non-brash articulation onstage, it's good... I'm listening to Me'Shell Ndegeocello's PEACE BEYOND PASSION right now - that'd be one style of mix the Acmes would be superlative for - in this case a mix with an uncluttered arrangement style with everything slotted just so, and very full, rich, sustained, and sometimes layered bass.

    Which brings up another thing I like about Acmes - you can play live using a full bass sound that's a lot more like what you hear on really good recordings - no throwing out the bottom octave just to get over. That's good for blues, reggae/dub, soul/R&B, hip-hop spinoffs, acid jazz, funk, horn bands, Headhunters-type stuff, many fusion and jazz stylings - and not so good for ultradistorted guitar bands, where the Acmes just don't have the upper mid and treble headroom to really do the "cut-through" thing.

    I like floating a band like a bottle with a note in it on the open ocean also, but also being able to punch right through any amount of distortion and clutter, so if I am not intruding to say my designs are kind of like Acme in the low end but have the goods to "cut through" and shine for styles where the Acmes are not as favored. They also sound glorious with bigtime distortion. They owe to my exposure to both types of cabs.

    I'm interested in what Andy will do next, given all the time bassists and he have had to evaluate where the current Acmes are weak and where they are strong.
  17. zombywoof5050


    Dec 20, 2001
    One of the bands I'm in is a Pink Floyd tribute band.
    Would a pair of Acme B2's sound good with this band?
    I would always use two B2's (4 ohm), and would be giving each 4 ohm cab 700 watts from my Carver PM1400 power amp, paired with an Alembic F-2B preamp and a Fender P-bass with flats. Do you think this would work well? I wish I could try the Acme's before buying, but I can't.
  18. That should do well i would think.
    Acme's are either loved or hated.. unlike Bergies.. or Aggies which almost all have universal appeal on this board.
    I would venture to say you REALLY have to listen to the acmes before you buy them... (moreso than with others listed) they have a tad different voicing, and thier own unique sound.
  19. rockstarbassist

    rockstarbassist Banned

    Apr 30, 2002
    The Woodlands, TX
    Endorsing Artist: HCAF
    I had volume problems with a 3Pro through a Mesa Deisel 610... :scowl:

    You would have had issues I do believe with that combo.
  20. Zooberwerx

    Zooberwerx Gold Supporting Member

    Dec 21, 2002
    Virginia Beach, VA
    Don't sweat it. If its a Pink Floyd tribute band, you won't have to play a note. Just feign ineptitude and let the lead guitarist cover your parts.

    Otherwise, the Acmes might be a good choice. Whereabouts do you live?


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