What to Do With Creased Acme Drivers?

[Zooberwerx]

Understood, although I certainly hope someone wouldn't be turned off to the cabs by reading about a couple of concerns voiced on an internet message board. Heck, any cab you name can have that baggage!

I think Acme undeservedly receives more than their fair share of questionable press: "power hungry", "inefficient", and on and on. If I'm buying a piece of gear and need a fair, unbiased review, I go to TalkBass for the true dope. A lot of people do the same. Our opinions carry more weight than you would imagine.

Riis

 

[KJung]

I think Acme undeservedly receives more than their fair share of questionable press: "power hungry", "inefficient", and on and on. If I'm buying a piece of gear and need a fair, unbiased review, I go to TalkBass for the true dope. A lot of people do the same. Our opinions carry more weight than you would imagine.

Riis

Actually, Andy himself uses the terms 'inefficient' and 'power hungry', and wears those terms like a badge of honor! These are not negatives, but do represent the uniqueness of the design (along with the three way design, etc.).

The key with these cabs is that IMO and IME, they are very different that typically voiced two way cabs. That differences is great for some styles of playing and some tone preferences, and not so good for others.

Deep low end extension comes with a price.... relatively high power requirements versus more 'traditionally' voiced speakers, some lack of perceived volume versus other cabs due to the wider, flatter, voicing, and some additional and special EQ requirements in some cases (high pass filters, etc.).

These are great cabs, and very high quality, but are surely not for everyone. And, for some with certain rigs and playing styles and tone goals, there can be some problems with them... like any other rather specialized piece of gear IMO.

 

[Folmeister]

Anthony at Eminence send his best to everyone. Eminence does, indeed, make Acme drivers, but has a closed agreement with Andy. This is the closest analog in the non-OEM Eminence line

http://www.eminence.com/guitar_speaker_detail.asp?model=LEGENDBP102&speaker_size=10&SUB_CAT_ID=5

Is the difference just the voice coil?

 

[Lonnybass]

These are great cabs, and very high quality, but are surely not for everyone. And, for some with certain rigs and playing styles and tone goals, there can be some problems with them... like any other rather specialized piece of gear IMO.

Couldn't agree more. Despite certain frustrations my experience was generally quite positive and I would certainly recommend Acme products if given an understanding of a particular player's goals and applications.

I'd also like ot give props to Lonny for not taking any of what has been written here and misunderstood it as a criticism of himself personally. I've seen far too many internet discussions go south when discussion is perceived as personal attack.

Now, let's get down to the personal attacks, shall we? It seems perfectly clear that NONE of you know what you are talking about!!!

Lonnybass

 

[KJung]

Couldn't agree more. Despite certain frustrations my experience was generally quite positive and I would certainly recommend Acme products if given an understanding of a particular player's goals and applications.



Now, let's get down to the personal attacks, shall we? It seems perfectly clear that NONE of you know what you are talking about!!!

Lonnybass

 

[Folmeister]

They are not even recycled by Eminence. The magnets are not even salvageable. They go in the trash. So sad, too bad. I have a B1 and a B2 and only use them when I can get fairly predictable cabin volume, like car speakers. Acmes work really well if you can use the room to get the most out of them.

 

[alexclaber]

I wonder if Andy would ever be interested in offering a version of his cabs with higher wattage (which I assume would mean more robust) speakers.

Actually higher wattage speakers wouldn't be any more robust because it is not thermal power handling that limits the output. The vast majority of woofers, Acme or otherwise, are damaged by exceeding their mechanical power handling - and due to Acmes' large excursion their mechanical power handling is roughly four times that of typical bass guitar woofers.

Jim Bergantino uses a similar 'long throw' high xmax design in his larger cabs, and those things handle power and slapping and wumping like nobody's business.

Jim's woofers have more Xmax than most but not as much as Acmes. But what makes the bigger difference is that Jim's woofers are squeezed into 'undersized' cabs which reduces their low frequency sensitivity and thus the cone excursion. You may say, but Acme cabs are just as small - the difference is that the Acme woofers have a lower Vas which means they can get full bass response from a smaller cab. the Bergantino cabs are also tuned higher so the port is sharing the load more through the 60-80Hz region, hence less excursion. If you try to get output from the Bergantinos at 30Hz the cones will leap madly!

It always struck me as unusual that the Acme's are known to 'want a lot of power' due to that deep low end extension, but then had one of the lower 'suggested maximu power ratings'... I think 250 watts for the B2... can't quite remember.

The Acme site recommends about 500W for the Low-B2. That a good amount assuming the amp is accurately rated and has plenty of peak power above that. Up to 1000W will get more output but you definitely need a 30Hz filter if you're playing with that much power.

I know Andy is trying to keep costs down, but I can imagine that those cabs with more powerful drivers in them might really be something.

How do you define a 'powerful driver'? The Acme woofer can move more air than other bass cab woofer. The difference between it and other bass cabs is that the design actually allows the speaker much fuller response. If you actually want to create deep bass at high SPL the only way to do so is to have a large area of speakers moving a long distance. So any cab whose speakers aren't moving much isn't actually producing much low bass. This is why you can hit the smaller Schroeder cabs with so much power because whatever you do the speakers are in such a small enclosure for their specs they cannot produce much output below 100Hz. But if you took these woofers, or the Epifani woofers, etc and put them in a larger cabinet which lets them movely freely and thus produce good sub 100Hz output, they'd have a much fuller deeper sound than in their existing cabs but run out of power handling long before the Acmes.

I have to say though that I started bugging Andy with similar questions some years ago and could never quite understand his answers. Having messed around with WinISD etc I can now see what's going on and why higher wattage speakers wouldn't make any difference.

'Watts' simply don't matter!

Alex

 

[oddio]

Andy's manual and the website are both fairly clear on the fact that heavy percussive tapping can cause a problem. I managed to crease a few cones exactly this way using an Aggie DB750, whereas I never had a problem using a DB680+QSC PLX with the 30Hz filter engaged even playing at much higher levels. If you slap and pop, going easy on the bass boost controls and the precaution of using a 30Hz (where the cabinet is tuned) or 50Hz high-pass filter does the trick for me. I haven't had a problem with an Acme since.

 

[KJung]

Actually higher wattage speakers wouldn't be any more robust because it is not thermal power handling that limits the output. The vast majority of woofers, Acme or otherwise, are damaged by exceeding their mechanical power handling - and due to Acmes' large excursion their mechanical power handling is roughly four times that of typical bass guitar woofers.



Jim's woofers have more Xmax than most but not as much as Acmes. But what makes the bigger difference is that Jim's woofers are squeezed into 'undersized' cabs which reduces their low frequency sensitivity and thus the cone excursion. You may say, but Acme cabs are just as small - the difference is that the Acme woofers have a lower Vas which means they can get full bass response from a smaller cab. the Bergantino cabs are also tuned higher so the port is sharing the load more through the 60-80Hz region, hence less excursion. If you try to get output from the Bergantinos at 30Hz the cones will leap madly!



The Acme site recommends about 500W for the Low-B2. That a good amount assuming the amp is accurately rated and has plenty of peak power above that. Up to 1000W will get more output but you definitely need a 30Hz filter if you're playing with that much power.



How do you define a 'powerful driver'? The Acme woofer can move more air than other bass cab woofer. The difference between it and other bass cabs is that the design actually allows the speaker much fuller response. If you actually want to create deep bass at high SPL the only way to do so is to have a large area of speakers moving a long distance. So any cab whose speakers aren't moving much isn't actually producing much low bass. This is why you can hit the smaller Schroeder cabs with so much power because whatever you do the speakers are in such a small enclosure for their specs they cannot produce much output below 100Hz. But if you took these woofers, or the Epifani woofers, etc and put them in a larger cabinet which lets them movely freely and thus produce good sub 100Hz output, they'd have a much fuller deeper sound than in their existing cabs but run out of power handling long before the Acmes.

I have to say though that I started bugging Andy with similar questions some years ago and could never quite understand his answers. Having messed around with WinISD etc I can now see what's going on and why higher wattage speakers wouldn't make any difference.

'Watts' simply don't matter!

Alex

This all makes sense, and I was just trying to come up with some sort of solution for the issues that some of us have had/have with these cabs. Quite frankly, it still seems somewhat silly to me to build in all that low end extension and then use a hi pass filter to eliminate some of that low From your description above, it seems Bergantino has come up with quite a good solution (at least in his larger cabs and IP's) that provides a lot of low end extension versus most other two way cabs (but not the extreme low end that seems to be causing the trouble and that many seem to eliminate anyway), high power handling, and also no need to use special filters or EQ's to either 'tighten up the tone' or keep the speakers from pistoning out the front of the cab.

However, I did assume that a speaker that was truly rated to handle more power would have less of a chance of being damaged like the Acme drivers. It seems I was wrong on that one.

 

[12bass]

Seems to me a 30 Hz high-pass filter isn't going to affect the fundamentals of the bass, just the unwanted rumble below....

 

[alexclaber]

This all makes sense, and I was just trying to come up with some sort of solution for the issues that some of us have had/have with these cabs. Quite frankly, it still seems somewhat silly to me to build in all that low end extension and then use a hi pass filter to eliminate some of that low

That's where people are going wrong - use a 30Hz highpass filter, nothing higher! Such a filter will lower the low B fundamental by 3dB which is pretty hard to hear - though if it bothers you you can certainly add a little bass EQ. The key with a filter is that the slope is very steep so that little power hits the cab below the tuning frequency without affecting the sound/output at and above the tuning frequency (if you try to do this with EQ then you'll end up removing the good 30-50Hz output as well as the high risk area below 30Hz due to the less narrow bandwidth of such controls)

This is absolutely standard procedure with any high power true woofer cabs but right now there is not one single other bass cab manufacturer that is producing cabs with true PA sub-like bass extension, hence no other bass cabs need this filtering because their response drops so much below 100Hz and thus excursion remains small enough. If you EQ your cabs to produce bass like the Acmes (though this is only possible down to the tuning frequency) then you'd start to see big excursion and thus a need for high pass filtering. (The IP cabs do exactly this and therefore have such filtering built-in).

I disagree with using a filter with a higher knee frequency - having tried the 50Hz filter on my QSC I found that it actually increased cone excursion because the port wasn't getting to share the load.

From your description above, it seems Bergantino has come up with quite a good solution (at least in his larger cabs and IP's) that provides a lot of low end extension versus most other two way cabs (but not the extreme low end that seems to be causing the trouble and that many seem to eliminate anyway), high power handling, and also no need to use special filters or EQ's to either 'tighten up the tone' or keep the speakers from pistoning out the front of the cab.

I like Jim's design approach, it's a nice halfway house between conventional cabs and Acme cabs. Unfortunately he doesn't sell anything that can produce such deep bottom from a smaller cab without the huge extra expense of a built-in amp with DSP. But there's nothing particularly special about a highpass filter - plenty of power amps have them built in, and if they don't you buy passive standalone filters to place in FX loop or between pre and power amp.

I know you've often commented on deep bass causing problems in a lack of tightness and excessive boom. I don't believe this is a direct result of deep bass extension - it's what happens whenever a cab is asked to produce more output in the lows than it is comfortable with, this therefore results in extra mid-bass output being created by the harmonic distortion. Most boom is as a result of excess output and room resonance in the 100-200Hz area, and that's exactly where those low note distortion overtones happen. Other issues are as a result of interaction between PA subs and the cabs - with any bass cabs and serious PA subs I strongly recommend EQing out your lows to prevent bad interactions.

The very low group delay, fast transient response and deep bass extension without EQ from Acmes actually allows them to produce far quicker tighter bass than any other cab on the market. HOWEVER, if your hands and instrument fail to create the lows you want to hear, in sounding too boomy or whatever, then you will hear that.

Alex

 

[KJung]

Again, makes sense. Just trying to brainstorm, since there are quite a few owners who have posted about these issues.

Also, FYI, I never had any problems with blown bulbs or creased cones with my B2's.... they just didn't quite work for my playing style, rather aggressive instruments, and the busy mixes that I typically work in. Great cabs if you are looking for that rather unique, deep, organic type tone!

 

[Lonnybass]

My head is spinning...

Lonnybass

 

[KJung]

My head is spinning...

Lonnybass

My brain is creasing

 

[Lonnybass]

My brain is creasing

This post made my day, and it's only 9:13 CST.

Lonnybass

 

[pogipoints]

I've also creased both speakers on my B2, using a Stewart 2.1, bridged to 8ohms, but that's my fault for using a single 2x10 with a semi-loud drummer. Now I use an Epi T310 for louder gigs.

I'm still loving the B2's sound though.

Question for alexclaber (of course anyone can chime in)

I see that you use the 30Hz filter on the PLX. How about the HPF on the SWR Grand Prix, will that work as good as the PLX's HPF?

 

[bassbrock]

I bought a used Acme B-2 back in January and it came to me with both cones creased. I was able to purchase replacements from Andy (he was very helpful, by the way, even though I wasn't a customer). I was burned by paying $400 bucks for the cab. Externally, it was in great condition.

I didn't realize the cones were creased at first until I started noticing that the speakers would 'fart' out at even moderate volumes. Just playing around in the house I didn't notice it. Once I hooked up with the rest of the band it was like Montezuma's Revenge! Reading around here on TB, I learned that the Acme's should NOT fart, even at loud volumes.

Since the replacements, I haven't had any trouble. Of course, now I've spent about the same as a new cab for a used, four year old unit. The seller I bought the cab from claimed no knowledge of the speakers being creased and said he sold it to me AS IS, so my problem. You couldn't really see the creasing until you removed the front grille, or if you shined a flashlight. He said he had bought the cab used himself but didn't have a use for it as he already had two B4 units.

My B2 gets stupid loud, even with two guitar players, a piano player, four vocalists and a stupid-loud drummer. I'm often asked to turn down!

 

[bassbrock]

Oh, and I was also going to note that IF my replacement drivers start to crease, I'm just gonna say heck with it and buy an EarCandy cab so I can fill a whole stadium with chest thumping bass with a single 2x12! ;-)

 

[Kindness]

My B2 gets stupid loud, even with two guitar players, a piano player, four vocalists and a stupid-loud drummer. I'm often asked to turn down!

This has been my experience with my B2 as well, but I wonder if I just don't need the ridiculous volume others must need.

 

[WCunha]

I bought a used Acme B-2 back in January and it came to me with both cones creased. I was able to purchase replacements from Andy (he was very helpful, by the way, even though I wasn't a customer). I was burned by paying $400 bucks for the cab. Externally, it was in great condition.

I didn't realize the cones were creased at first until I started noticing that the speakers would 'fart' out at even moderate volumes. Just playing around in the house I didn't notice it. Once I hooked up with the rest of the band it was like Montezuma's Revenge! Reading around here on TB, I learned that the Acme's should NOT fart, even at loud volumes.

Since the replacements, I haven't had any trouble. Of course, now I've spent about the same as a new cab for a used, four year old unit. The seller I bought the cab from claimed no knowledge of the speakers being creased and said he sold it to me AS IS, so my problem. You couldn't really see the creasing until you removed the front grille, or if you shined a flashlight. He said he had bought the cab used himself but didn't have a use for it as he already had two B4 units.

My B2 gets stupid loud, even with two guitar players, a piano player, four vocalists and a stupid-loud drummer. I'm often asked to turn down!

I know this is an old thread but I was searching for some answers and my B2 doesn't seem to get stupid loud. I would like it to though since I love the tone it puts out.

I just had a practice last night in a small room with a loud drummer and one loud guitar player and I have to say my one Acme B2 just could not keep up on its own and I really don't want to drag my second one over there.

I love the sound of them and have had them for quite a long time but I do get nervous about damaging them. I think a big part of it is that the guitar player just doesn't know how to dial in his tone. It can be so drowning in a little room. I'm thinking of changing cabs that I can slap the snot out of.

I do need something that is full range like a PA cab. I use a Pod X3 as my preamp and have had great success with the tone. I love the tone but I need something loud. Power shouldn't be a problem I use a Peavey DPC1400X bridged. If I had the time I think I would build a fEarful.