Acme and Accugroove???

[Gruuve]

Just curious here folks...both of these are positioned as the cabs with the closest-thing-there-is-to "flat" response. Both certainly look to be engineered very well.

 

So, here's the part I'm curious about. On the Acmebass.com web-site, Andy mentions that it's not possible (due to physics) to have a driver that has extreme low-frequency response AND still have reasonably high sensitivity. One of the big components of LF response is the cone excursion (how far the cone can actually move back and forth), and it even makes intuitive sense that it takes more power to move a cone than can move further. In keeping with this, the Acme LowB2 has a sensitivity of 93db/1W/1m, and the LowB4 has a sensitivity of 96db/1W/1m.

 

Keeping this physics constraint in mind, I notice that most of Accugroove's cabs have much higher sensitivities...like in 100-102 db/1W/1m. So, can anyone explain this apparent anomole, because I'm really curious?

 

Dave

[wurmhole78]

I too am curious about any hard, and/or inside info on this subject as well, however, here's what I've dug up super fast.

 

For one, upon comparing the Low B-II to the Tri210, the Acme is roughly 62% as large as the AG. It is also 7 lbs. lighter without the use of Neo drivers.

 

Second, the AG has a slightly larger mid driver (6 vs. 5in.) as well as a second tweet. I'm guessing the noise they make have a little something to do with the final sensitivity rating.

 

Oh yeah, and for 800 bucks you should get some magic.

[LLroomtempJ]

My guess:

 

Accugroove cabs have multiple drivers. Smaller drivers to handle higher frequencies and larger ones to handle lower frequencies. Acme's are just regular cabs.

 

I also would venture to say that Accugroove 10s are probably some patented technology which allows them unprecedented low end response...but what do i know?

 

mr whappo himself should make an appearance soon. If i'm right i'd expect him to make me some sort of job offer seeing that i'm a senior in mechanical engineering.

 

<--at mark from accugroove

 

jason

[Gruuve]

Wurmhole78,

 

Actually, that's a really good point. The cab volume is always a restriction (unless it's really bizarre design). The resonant frequency of the driver in the cab is always higher than the resonant frequency of the driver in open air. The smaller the cab volume, the higher the resonant frequency gets pushed, and the more power/cone excursion/etc. required to get the same LF response.

 

Dave

[wurmhole78]

Just for future reference, ACMEs are 3-way speakers. Much like the AccuGroove. I'm really not trying to fight the fight for ACME, I haven't played through AGs, I'm sure they are as super duper as they should be for their price point.

[Whappo]

Good questions. Ive talked with Andy before & hes a great guy & builds nice cabs.

 

it's not possible (due to physics) to have a driver that has extreme low-frequency response AND still have reasonably high sensitivity.

 

The issue of sensitivity is multifaceted & not an easy one. The first drivers we had developed sounded great, but they were not very loud. Most of the time there is a trade off between sensitivity and the sound you are looking for. If you get one, you may have to compromise on the other. (In keeping with the quote above)

 

However, after testing 1,200 different drivers from 6 different countries, we finally got things nailed down where we were able to get the best of both worlds. It wasnt easy. But if it was, everyone would be doing it. There are over 21 different parameters that can be changed like a Rubiks Cube to make the driver do what you want. What a puzzle?

 

After worrying about the driver, its the cabinet design that also contributes. This includes volume, porting, tuning, material, etc. By the time you make many small changes to multiple items, it can add up.

 

The bottom line is that like us, Andy makes his cabinets unique & different compared to what everyone else does. We builders choose a path we think is best & hope that players tend to agree.

 

Are our specs correct? You bet your low B string!

 

Whappo

AccuGroove

 

<--to Jason from accugroove

[...]

Something in Whappo's post above speaks volumes and might be overlooked for whatever reason. It's a lesson I learned in my interest in high end audio years ago. No matter how good your speaker is, if your enclosure is crap; it

's going to sound like crap. The enclosure design can so amazing things to a speaker. It can make a cheap speaker sound like the best thing ever and it can make the most expensive driver you can find sound like absolute butt. I have heard Whappo's cabs and I think that he and his crew have found an excellent combination of speakers and cab design. The Accugroove stuff sounds smooth, is responsive, and is honest to how your bass really sounds. One of these days, I'm going to stick my money where my mouth is and buy an El Whappo cab or two.

[alexclaber]

The key difference seems to be AccuGroove giving each driver more volume to operate in and then removing most of the weight gain through cunning bracing and neo drivers. And then tweaking every last ounce of potential with lots and lots of R&D. IIRC Mark once mentioned that they've never even tried to cover their original R&D costs - a true labour of love!

 

If you compare the cab dimensions for Acme and AccuGroove's 2x10" and 1x10" models you'll see that the AccuGrooves are about 70% larger than the Acmes. They also have a higher tuning frequency and steeper roll-off. This means they don't put out quite so much on the fundamentals of the lowest notes but they gain quite a lot of sensitivity as a trade-off. To be honest, I don't think you need so much output right down there so it's a good compromise. The extra sensitivity gained beyond the extra cab volume and reduced ultra lows, is no doubt due to almost a decade's improvement in raw speaker design and all that experimentation in getting the perfect speaker/cab match.

 

Sensitivity, frequency response and RMS power handling doesn't tell the whole story - for bass amplification the limitation of a speaker's power handling is excursion related, which varies with frequency, and bass output is directly related to excursion multiplied by projected area. So although all the AccuGroove cabs will be louder than the Acme ones with a given amount of power, the Acmes' maximum output will not be as far behind as you'd think. But you will need to use a bigger amp to get there.

 

Irregardless, with both these companies you get significantly more than you pay for!

 

Alex

[Gruuve]

Hey Mark:

 

Thanks for the reply...nothing like hearing the skinny from the designer!

 

I'm sure no one doubts the specs from either of you guys...now that you've offered an explanation, I see that the differences are more decisions made in terms of design tradeoffs moreso than any magical physics at work!

 

Thx,

Dave

[Big Daddy from Motown]

Whappo how do you measure the sensitivity of your speakers? At what frequency?

You tested 1200 drivers? I'm impressed that you had that much start up capital.

[alexclaber]

Originally posted by Dave Sisk:

I'm sure no one doubts the specs from either of you guys...

They should doubt the specs, based on those quoted by the majority of bass cab makers... And then be pleasantly surprised that Acme and AccuGroove are amongst the select few that don't just pluck marketable numbers out of the air but actually speak the truth!

 

BDFM, from Mark's previous writings I got the impression that AccuGroove was never intended to be a business, just a tone obsessed bassist and a hi-fi expert buddy indulging themselves trying to make the best cab they could, and spending a fair wodge doing so. Who were then coaxed into producing cabs for public sale once other bassists had heard it. Of course, I may be wrong, it's happened before...

 

Alex

[Big Daddy from Motown]

Alex being an electronic tech. i've got enough test equipment to do frequency response measurements, and i'm forced to agree with your comments concerning frequency response of bass cabs. I've haven't measured either Acme's or AccuGroove's but the dozens of cabs i have measured have all dropped off like mad below 100 HZ. Most are unable to produce much clean volume at 40HZ let alone the 29HZ of low B.

[Tom Capasso]

This has been an interesting thread. The surprise I got was that I never heard anyone refer to AccuGroove as "flat". I've heard this about Acme, and I know that many other high-end companies come close to flat, but that is not usually the goal. I'm splitting hairs here, but most cab makers want to reproduce the full range of sounds, but exactly flat?

 

thanks to all, especially Mark.

 

Tom

[Gruuve]

Actually, I guess I was under the impression that Accugroove is slated as one of the "flat responders". Maybe that is actually incorrect! I've generally, heard Accugroove, Acme, and EA lumped into the flat category, but that may have been implicit rather than explicitly intended.

 

Good catch Tom!

 

Dave

[alexclaber]

From the AccuGroove website regarding the El Whappo: "It's like a giant studio monitor..." To me that equates to flat response.

 

Alex

[alexclaber]

And EA: "At EA, we believe that neither amps nor speakers should have tone."

 

And Acme: "Flat Frequency Response."

 

I don't know of any other bass cab manufacturers making such claims or having this philosophy, but I do know that Bergantino comes fairly close with their HT range, though by striving to impart a more subtle colour than typical, instead of aiming for zero colouration.

 

Alex

[Gruuve]

Good posts Alex. However, I disagree on the Bergantino's...I've got an HT322, and it is far from anything remotely resembling flat. It does have very good LF extension, but the mids are very colorful and pronounced. My basses sound entirely different through the SWR head and Berg HT-322 than they do through my studio monitor setup (M-Audio BX8's and a Samson 120a Resolv sub). It's a fantastic sounding cab, but it's most definitely not flat!

 

I also find that my tone is quite different going through the SWR+Berg than it is the church PA (where we use PA only).

 

I really like how the Berg sounds, but I'm seriously considering now taking the flat approach. In terms of getting the same sound in recording, church, and through my rig, there are some definite advantages to this approach. There might be an Acme or Accugroove in my future.

 

On the EA's, I haven't had an opportunity to try one of their newer cabs. I did once play through one of their previous generation cabs that had 2-10's, 2-6's, and a tweeter...don't remember the exact model. I was not at all impressed. If I so much as touched the B-string, it immediately farted out. It looked cool, but the utility ended there. Maybe their newer cabs have more to offer, but that experience certainly left a bad taste in my mouth.

 

Dave

 

 

Dave

[alexclaber]

Originally posted by Dave Sisk:

Good posts Alex. However, I disagree on the Bergantino's...I've got an HT322, and it is far from anything remotely resembling flat.

Ah yes, that is renowned as a grunty cab. The HT-310 and HT-112 seems to stack up well as PA cabs according to Tom Bowlus, and he'd know!

 

Originally posted by Dave Sisk:

On the EA's, I haven't had an opportunity to try one of their newer cabs. I did once play through one of their previous generation cabs that had 2-10's, 2-6's, and a tweeter...don't remember the exact model. I was not at all impressed. If I so much as touched the B-string, it immediately farted out. It looked cool, but the utility ended there. Maybe their newer cabs have more to offer, but that experience certainly left a bad taste in my mouth.

Unless the cab was broken (which I doubt) I can guarantee that was 100% down to the amp having insufficient power to drive the VL-210. The VL-210 is pretty much the loudest and deepest 2x10" that's ever been produced and can handle absolutely massive amounts of power without farting out - like well over 1000W per cab. Unfortunately they weigh more than some 4x10" cabs. Like Acmes they take a lot of power to go loud and low, so more modestly powered amps will really struggle to push them to useful volumes.

 

Alex

[Whappo]

Whappo how do you measure the sensitivity of your speakers? At what frequency?

For final specs, we flew our cabs to a professional Sound Engineering company over a thousand miles away to ensure our gear would be fairly & correctly tested using only the best equipment & facilities. We put two specs out for each cabinet because various manufactures tend to publish one or the other. The El Whappo, as an example: Freq. Re. & SPL: 35 Hz - 18 kHz (29 Hz@-6db) 102 dB SPL. These are tested at 1 watt, 1 meter.

 

Whappo

AccuGroove Speaker Cabinets

[Gruuve]

Alex:

 

Ah...OK, that could very well be the case with the Berg then...I can't speak with any experience for any others except the HT212 and HT322. It does indeed have ample grunt.

 

Hmmm...I'm actually wondering if maybe the EA cab I tried actually was broken (it was in there on consignment, as were most of the cabs and amps). I don't recall it being that large...I'm trying to find a pic, maybe it was a 1-10 + 1-6 + tweeter. I guess I've flushed it out of my memory since it was such an unpleasant experience!

 

The problem definitely was the cab though. The amp was one of the Mesa-Boogie 600 or 800 watt full tube amps. I tried it with a couple other cabs in the place, and I can definitely say it had plenty of juice to offer.

 

Dave

[Whappo]

You tested 1200 drivers? I'm impressed that you had that much start up capital.

Mark once mentioned that they've never even tried to cover their original R&D costs - a true labor of love!

BDFM, from Mark's previous writings I got the impression that AccuGroove was never intended to be a business, just a tone obsessed bassist and a hi-fi expert buddy indulging themselves trying to make the best cab they could, and spending a fair wodge doing so. Who were then coaxed into producing cabs for public sale once other bassists had heard it.

From the AccuGroove website regarding the El Whappo: "It's like a giant studio monitor..." To me that equates to flat response.

It was a personal project to solve my private frustration of not being able to get the true sound of my instrument live that I could get in the studio. Over 30 years had been spent buying & selling what was supposed to be the best gear on the planet & it still didnt work for me. I finally cracked & reluctantly decided to do it myself with the help of my good friend David Innis. (Now my business partner)

 

The only criteria were the perfectly pure, true studio sound of any of my basses at any live venue. I did not care how long it took nor did I care how much it cost. If I would have been trying to start a company I would have cared deeply about cost & time, but then we never would have had the same results. (For the record, my other company spent over $50k for this personal project)

 

After a couple of years when we were done, that was it. I had my cabinet & I was fat, dumb & happy. However, pro players starting hearing my rig & wanted to place orders for the world tours. I still did not want to start a company & refused to build them anything. Eventually we were hounded to death & realized we were being selfish.

 

Im the first to admit that we are not the best business people because to this day, we design a cabinet, beta test it & send it out on tour. We do not care how long it takes or how much it cost. Only after it is completely ready to bring to market do we reverse engineer it & find out what it cost to build. Time & money never factor into the design of our cabinets, only the sonic value.

 

A case in point is our Tri 210L. 4 years ago we had pro players telling us it was the best 2x10 they ever heard, however I was not completely happy. So, we spent another 3 years fine tuning it until it met my demands.

 

I hope this helps you to get a better picture of the what & why of AccuGroove.

 

Humbly,

Whappo

AccuGroove Speaker Cabinets

[alexclaber]

Originally posted by Dave Sisk:

Hmmm...I'm actually wondering if maybe the EA cab I tried actually was broken (it was in there on consignment, as were most of the cabs and amps). I don't recall it being that large...I'm trying to find a pic, maybe it was a 1-10 + 1-6 + tweeter. I guess I've flushed it out of my memory since it was such an unpleasant experience!

The VL-210 isn't a big cab, it's smaller than a Tri-210L, but it's incredibly dense due to the transmission line design and 5 high quality drivers - it's half the size of your HT-322 but about the same weight!!!

 

Originally posted by Dave Sisk:

The problem definitely was the cab though. The amp was one of the Mesa-Boogie 600 or 800 watt full tube amps. I tried it with a couple other cabs in the place, and I can definitely say it had plenty of juice to offer.

I still think the problem was probably the amp - there's no way a full tube amp could be anywhere near 600 or 800 watts, in fact the only all-tube dedicated bass head made by MESA puts out 300W on a very good day with a following wind. Just because that amp sounded loud with various conventional bass cabs doesn't mean it had enough power to drive the EA.

 

FWIW, EA's new cab designs are far more efficient and much lighter. They're not quite so precise sounding or capable of quite such unflappability at silly SPL, though.

 

Alex

[Gruuve]

Alex:

 

Actually, the amp was a Mesa Boogie M-Pulse 600.

 

http://www.mesaboogie.com/Product_Info/Bass_Amps/M-Pulse-600/M-Pulse-600.html

 

I was incorrect, it's not all tube...the power amp section is some sort of hybrid tube + mosfet deal.

 

I've tried to open the archive section of EA's product list, but the link doesn't seem to work.

 

Dave

[alexclaber]

For enlightenment on all things flat(ish)-frequency-response and bass cab related, this is the man to talk to, as he owns most of them!

 

http://bowlusblog.blogspot.com/

 

Alex

[davio]

Oh my goodness...

 

I was looking at his list of gear and wondering where he would keep all of that stuff with a family sharing the house. Then I got down to the pics...*drool* Maybe I should've shot for law school.

[Tom Capasso]

From talking to Jim B, I would say "flat" is something he is aware of, but not what he strives for in every cab. He plays music through the cabs to test them, but I think anyone who has heard an HT322 knows that this is a bass cab, not a hi-fi cab. I agree with Alex on the HT112, and have used it for keys with sparkling results. Jim has other customers that have used these cabs as PAs in a pinch.

 

I stand corrected as to who is working toward flat (thanks Alex!). Just the same, I heard the EA cab with 1 12. I can't say I fully tested them (music, etc.), but they didn't seem "flat" as much as they seemed "pure". In other words, all frequencies seemed clean, but the emphasis was down low. I liked them.

 

Mark - thanks for the history/methodology lesson. Having seen how a few cab makers work, I'm starting to think I should write a book on cabs like Jim Roberts did on American Basses. I don't have the tech background to do it justice (who's that guy Fletcher, and what does he want with Munson?), but it's an idea.

 

Tom

[ArwinH]

Originally posted by Tom Capasso:

 

I Just the same, I heard the EA cab with 1 12. I can't say I fully tested them (music, etc.), but they didn't seem "flat" as much as they seemed "pure". In other words, all frequencies seemed clean, but the emphasis was down low. I liked them.

 

 

Tom

I just found out yesterday that the founder of ea cabinets used to work in audiophile electronic systems when his until his friend Michael Tobias let him know about an interes in small, yet powerful and good sounding amplifiers and cabinets for bass players. So then he used his previous knowlede to start ea amplification.

Pretty cool, I think.

[g.]

Wasn't around when this thread rolled...

 

Big Daddy from Motown: You tested 1200 drivers? I'm impressed that you had that much start up capital.

It's pretty easy to test a lot of drivers in a speaker cab sim/modeling program. Then you can winnow out a majority right on the computer. You knew this, I suspect ; }

 

Alex being an electronic tech. i've got enough test equipment to do frequency response measurements, and i'm forced to agree with your comments concerning frequency response of bass cabs. I've haven't measured either Acme's or AccuGroove's but the dozens of cabs i have measured have all dropped off like mad below 100 HZ. Most are unable to produce much clean volume at 40HZ let alone the 29HZ of low B.

Yup. Many bass cab companies have gotten away with murder for decades because they were selling to a credulous market that WANTED to believe all the ridiculous claims for response, sensitivity etc. And all the while other builders had to weigh in their minds and hearts whether to join the fray with specs figuratively inflated with heavy equipment compressors to near-bursting - or to look worse on paper but to be presenting data that ws essentially truthful - though hardly anybody used AES guidelines or qualified how they arrrived at their figures or graphs.

 

I still wish the bass cab industry would

 

(1) educate the consumers of their products, how specs are relevant, and how some may not always want just the best numbers but also voicings that are appropriate for their intended use.

 

(2) follow the SR industry in testing and publishing procedures.

[alexclaber]

I'd just like to retract all the comments I made above supporting AccuGroove. Current evidence points to me being wrong. Yes, I know, it doesn't happen often...

 

Alex

[g.]

Other than the Accuswitch stuff I see Accugroove no more blemished than a lot of other big name (in bass guitar circles) boutique cab companies who've made outrageous claims in specs and/or ad copy. From working as an engineer, and researching and buying a lot of gear for SR and studio, it just seemed amazing that buyers were going around and dissing what others had using those specs as indicators of objective truths.

 

In the SR and studios sectors the specs actually chart something that also translates into the character and reliability and performance; there they are useful for both purchase decisions and use. Of course, the scenarios are a little more complex for those sectors too - it isn't just people who want to be loud or whatever ; }