12" cab, high power handling recommendations

[monsterthompson]

All of this watts, SPL, displacement, yadda yadda yadda, is a lot like gas mileage claims for vehicles. You have to know all of the parameters involved in the test, horsepower, wind drag, weight and so on. You must have repeatable exact conditions to make comparisons. You can't say a Ford Zippy gets better mileage than a Chevy Chimp just by driving them around. Both cars must be subject to identical conditions, same gas, same route, same driver, same weather and much more. Nor can you compare one speaker/cab owned by Jack and played at gig A, to one played by Jill at gig B. To make a fair comparison, both cabs must be operated under identical conditions at the same time.
Subjective comparisons are just that, subject to the preferences of the person using it and the conditions of its use. As many have said before, and just like with cars, your mileage may vary.

And for the record, skepticism is the very foundation upon which science is built.
Scientist, engineers and technicians understand that.
If you are not of those disciplines it can seem to be a strange concept.

This.

The OP asked for a cab with specific criteria (12" & 800w). I think the majority of known cabs that approach that criteria (either based on advertising or anecdotal claims) have been posted.

 

[ThisBass]

Any recommended amplifier power tells nothing but recommended amplfier power.
So there is no stated number how much of average power is produced once transients of the signal do a cut off at headroom ability of the amplifier.

Any attempt to derive rather standard driver power handling (AES, RMS) from recommended amplifier power is just nothing but reading in crystal ball.
Very likely the BB-2 driver comes with a large Xmax of around 10mm but rather "generic" VC diameter of 3" at most.
Based on the given SPL 1Watt 1meter of 97dB I'd expect a 2.5" VC.
In a rather conservative mind thinking a driver of this ranking should provide appro 300..400 watt "thermal" power handling.
So in regards of power handling the BB-2 loaded driver very likely isn't any better than generic mass production drivers.

Way to often the relationship between dynamics of a signal and it's average and it's crest number is untended.

given SPL of 1watt 1meter: 97dB
To get 107dB SPL implies the need of amplifier power of 10watt minimum
To get 117dB SPL implies 100watt amplifier power.

Any consideration like this is missing the point in real world practice cause audio signals are rarely distinct steady sine waves.
How much amplifier power actually is needed to get a distinct "average" of SPL depends on the signal itself.
If the crest number of a given signal results in 9dB peak to rms ratio THEN the needed amplifier power would read like the following
97dB: 6watt
107dB: 60watt
117dB: 600watt

Depending on the distinct nature of a given signal there may be less or more amplifier power neccessary to get a distinct "average" of SPL.

A larger driver Xmax may enhance the "recommendable" amplifier power but there is no automatism the "standardized" power handling was enhanced just the same way.
recommended amplifier power <> standardized power handling (AES, RMS)

With a bass guitar I wouldn't expect more than 1/4 average of amplifier potential in a long term view.
That's around 200 watt "thermal" strain to the driver in combination with a 800watt amplifier, while mechanical strain was at "full power" just the same time.

While SPL numbers for 1watt 1meter may be very usefull to compare different drivers/cabs IMO it makes no sense to rate a distinct max. SPL based on max amplifier power.
Unless the signal itsels is unknown there is no way to predict any distinct average SPL, if in doubt I'd discount -6 .. -9dB off by default to get a rather real world number for bass guitar application. With an 800watt amplifier I'd expect around 100..200watt average, so a cab with 97dB "sensitivety" would give me around 117dB of noise at best if the driver as well suffers on some compression losses.
117dB <> 127dB

 

[agedhorse]

Yes I hear what you are saying. I'm rarely interested in a driver's power rating. I tend to look for the F3, the excursion and the max SPL. As you said...at 400w most drivers are way past a linear response. I still think that there is more power safety and SPL in using multiple drivers / cabs.

Let me expand on this a bit, because you are hinting at an important part of the comparison equation except that you are missing one important term, and using an industry mid-stated description for another term, plus simplifying a third term (probably without realizing it).

1. Excursion is a term that can not be directly compared without considering other variables that are tightly interwoven with it. To double the excursion, the displacement doubles (Sd x excursion) but this places all of that additional wire outside the magnetic gap. This means that the sensitivity decreases by almost the same amount unless the gap height increases which requires a stronger magnet to maintain flux density. A taller gap height requires a few more thousandths of clearance which decreases sensitivity, and increasing magnet size/weight is not a 1:1 proposition to increasing gap strength because of geometry issues. The greater winding height will generally increase moving mass and inductance, both of which decrease high frequency response (mid voicing potential). Additionally, the resistive portion that ends up residing outside the gap serves to increase Q which Ames the system appear more sloppy (less tight) So, displacement doesn't exist in a vaccum without considering its impact on other very important variables. Often, better overall performance for MOST players occur where sensitivity and excursion are balanced.

2. F3 represents only a single point in the rolloff knee of the frequency response. The low end of the frequency curve is mathematically described as a set of electrical filter equations, because electrical and mechanical systems share many identical properties. Aside from F3, there is the rolloff slope(s) and the Q that describe the behavior surrounding rolloff. The Q in this case represents the total damping and the rolloff slope represents the interaction of the various parameters responsible for the rolloff. A shallower slope with a higher F3 and a lower F10 might be better (a lot better) for some players. The distance between F3 and F10 divided by 7dB give you the slope. This is part of what makes a sealed cabinet desirable for some player. The Q more or less translates to the tightness if the response, this too is usually lower in a sealed cabinet resulting in a tighter feel.

3. Maximum SPL is something that needs to be well defined before making any comparisons because this is not an easily derived or measures number. In fact it's not even a single number but a set of numbers that vary with power, excursion and temperature. Remember my comments about non-linearity and the large signal model? Since most manufacturers calculate max SPL from the ideal small signal model, the non-linear terms (thermal, flux modulation, electromagnetic saturation, mechanical suspension losses) must be subtracted out from the max SPL that extrapolated purely from the small signal model. This can easily result in a 6dB difference between real and theoretical... a VERY significant difference IMO.

Hope this helps.

 

[Old Garage-Bander]

Let me expand on this a bit, because you are hinting at an important part of the comparison equation except that you are missing one important term, and using an industry mid-stated description for another term, plus simplifying a third term (probably without realizing it).

1. Excursion is a term that can not be directly compared without considering other variables that are tightly interwoven with it. To double the excursion, the displacement doubles (Sd x excursion) but this places all of that additional wire outside the magnetic gap. This means that the sensitivity decreases by almost the same amount unless the gap height increases which requires a stronger magnet to maintain flux density. A taller gap height requires a few more thousandths of clearance which decreases sensitivity, and increasing magnet size/weight is not a 1:1 proposition to increasing gap strength because of geometry issues. The greater winding height will generally increase moving mass and inductance, both of which decrease high frequency response (mid voicing potential). Additionally, the resistive portion that ends up residing outside the gap serves to increase Q which Ames the system appear more sloppy (less tight) So, displacement doesn't exist in a vaccum without considering its impact on other very important variables. Often, better overall performance for MOST players occur where sensitivity and excursion are balanced.

2. F3 represents only a single point in the rolloff knee of the frequency response. The low end of the frequency curve is mathematically described as a set of electrical filter equations, because electrical and mechanical systems share many identical properties. Aside from F3, there is the rolloff slope(s) and the Q that describe the behavior surrounding rolloff. The Q in this case represents the total damping and the rolloff slope represents the interaction of the various parameters responsible for the rolloff. A shallower slope with a higher F3 and a lower F10 might be better (a lot better) for some players. The distance between F3 and F10 divided by 7dB give you the slope. This is part of what makes a sealed cabinet desirable for some player. The Q more or less translates to the tightness if the response, this too is usually lower in a sealed cabinet resulting in a tighter feel.

3. Maximum SPL is something that needs to be well defined before making any comparisons because this is not an easily derived or measures number. In fact it's not even a single number but a set of numbers that vary with power, excursion and temperature. Remember my comments about non-linearity and the large signal model? Since most manufacturers calculate max SPL from the ideal small signal model, the non-linear terms (thermal, flux modulation, electromagnetic saturation, mechanical suspension losses) must be subtracted out from the max SPL that extrapolated purely from the small signal model. This can easily result in a 6dB difference between real and theoretical... a VERY significant difference IMO.

Hope this helps.

WOW! I must have stayed in the right hotel last night because I feel pretty smart right now.

I have a good background in electronics, but not so much in speakers as a subspecialty.
(Might have said woofers as a SUB specialty.) Groan.

I know just enough that I can follow what you say and that helps me learn more about this fascinating subject.
The concepts and terminology are familiar ground for me, and that helps me to be able to wrap my head around what you say.

Thank you Agedhorse, for being the guy who is willing to take the time to explain these things as well as you do, in spite of the detractors.

People who fear your charts and graphs apparently just don't have the background to understand them and equate them to being the tools of Voodoo. There is nothing wrong with not understanding complex ideas, unless they also think that when someone take a photo of them, that person has stolen their soul.

If any non-technical person would read your posts and pick out just one piece of jargon or one small concept, and Google that so as to better understand that single point. And continue to do that when something new pops up, they would increase their technical knowledge immensely. I've worked for well over fourty years as a electronics technician, and I still do web searches to help me better understand something of which I am not clear.

There is no shame in lacking knowledge as long as it partners with a willingness to increase one's knowledge.

 

[agedhorse]

WOW! I must have stayed in the right hotel last night because I feel pretty smart right now.

Did they at least leave the light on for you?

When you mentioned (pro) subwoofers, yes it is possible to get high power handling and reasonably good sensitivity numbers and good LF response but of course the tradeoff is HF response... which is a MAJOR difference between a driver that is a good choice for bass guitar and one for sub frequencies. Most high powered sub drivers are sorely lacking above 1kHz, and what's there is full of distortion harmonics because drivers are not only non-linear with respect to power but also to frequency.

Man, there's just no free lunch these days!!!

 

[R Baer]

This is just not true. Audiokinesis, Baer, Bergantino, Warwick, and Mesa all have drivers that they have designed themselves or specifically for their applications, and I am sure there are more.

Literally all of the companies you mentioned use either stock drivers or moderately modified stock drivers.

As Agedhorse mention in his reply, it is just too expensive for the average bass amp company to create custom parts due to the huge tooling fees and minimum order qualities involved. So, while it's true that we design around stock mechanical components, like the basket, cone, spider, etc., things like the voice coil can be wound to our exact specs. We also have control over a few other variables as well. Our current 12" driver was the result of over a years worth of R&D with Eminence, which involved making numerous samples and tweaks to get the drivers to act and sound just the way we wanted them to.

Think of it this way. Imagine 10 chefs who are tasked with making a pot of chili. Each chef is given the choice between dozens of different ingredients from which to create his recipe, but each chef may only choose 10 ingredients total. Given the many variations that are now possible, it's easy to imagine how differently each recipe can taste from the others.

An amazing amount of work can go into a "moderately modified" driver.

 

[Turn Em Loose]

1100 watts into one speaker is a surefire way to kill that speaker. However, if you're set on a 112, then I would recommend the Barefaced Big Baby 2 or the Super Midget.

This.

 

[sratas]

And for the record, skepticism is the very foundation upon which science is built.
Scientist, engineers and technicians understand that.
If you are not of those disciplines it can seem to be a strange concept.

Sorry, my job is clinical research, and I have an honoured career. I have more than a few experimental works published on high impact factors medical papers, mainly usa based

Skepticism and preconceptions do not belong to science, but to common people and superstition. logic thinking, experimental method, and concrete proofs are. What I was saying is that if someone wants to say that cab A is not capable of...etc etc, it has to own one, test it, measure it, and then he can come back to me. Or, if it has been claimed something unfair and untrue by the manufacturer, I wanted to know.

 

[ThisBass]

In the world of audio engineering there are a couple of common standards that apply to a very "specific" consideration.
The most common fault is to apply a common standard to every situation possible, which then is missing the point cause every application and situation is very special on it's own.
It was just the same like merchandse only one medicine for different symptoms of disease.

As in the audio world it's impossible to have common standards that capture every personal requirements and specific situation, so every approach to a solution must be done in a different way.
At first there is need to really understand the proposition of a common standard and also there is need to understand why a common standard exists as is.
For example, driver power handling can be determined differently, one possible approach is based on Zmin, while an equivalent approach is based on Znom.
As both ways lead into substantial different numbers of power handling someone may claim that only one approach can be true while the other one is done only for marketing department reasons.
Nothing at all, it all depends. It depends on what exactly I want to know about a driver and the meaning for a distinct "specific" application.

A very similar fault may be often done with all kinds of SPL considerations. Although the given common standard 1watt 1meter can't be directly translated into high powered systems and specific applications this common standard isn't impractical per se.

Manufacturers stated compression losses, sample of 12" driver 450watt with a 3" VC

Note: These losses are calculated from a five minutes AES power test
applying band limited pink noise (25-1200 Hz). The loudspeaker is free-air
standing.


In a rather simplistic consideration I could claim the compression losses will be -5dB if the driver is powered by a 450 watt amplifier running at full power.

In a more realistic consideration I'd do at first an assessment of the signals crest and then estimate the losses for a 450 watt amplifier. As I personally like a somewhat compressed tuby sound, and also prefer a more melodic bass line playing I claim the average does not exceed 100 watt with a 450watt amplifier running at full.
So instead of -5dB compression losses with the amplifier running at full power there will be only appro -2dB but the amplifier still running at full power.

The average of 100watt then also tells how much of noise I will get based on the standard SPL 1watt 1meter.
SPL 96dB 1watt 1meter
100watt: 116dB
compression losses -2dB
100watt: 114dB

I think that's plenty of noise for a single 12" driver powered by 450watt amplifier.

Note, the sample for the compression losses are calculated for pink noise. Although it isn't explicitely stated, to power a pink noise +6dB peak limited signal of 450watt means there is need for a power amp of 900watt minimum.

 

[bdplaid]

Skepticism and preconceptions do not belong to science, but to common people and superstition. logic thinking, experimental method, and concrete proofs are.

+1. Right. You reminded me of the trouble had by Galileo, Lister, Pasteur, etc. Cold-hearted logic and evidence, yes.

 

[agedhorse]

Skepticism most certainly has its place, anybody remember the supposed link between vaccines and Autism? That link did not hold up, the skepticism presented by the science community was found to be healthy when the study linking Autism to vaccines was proved to be fraudulent, using made up data.

The same applies to any claims of devices that return greater than 100% efficiency (plenty of examples) or of perpetual energy devices.

 

[sratas]

+1. Right. You reminded me of the trouble had by Galileo, Lister, Pasteur, etc. Cold-hearted logic and evidence, yes.

Galileo was at the top of my list when I was writing this.

Accidentally, or not, Galileo was also the pionneer of the experimental method, the absolute cornerstone of scientific experiments...hypothesys-experiment-conclusions

Ok...

 

[Old Garage-Bander]

Sorry, my job is clinical research, and I have an honoured career. I have more than a few experimental works published on high impact factors medical papers, mainly usa based

Skepticism and preconceptions do not belong to science, but to common people and superstition. logic thinking, experimental method, and concrete proofs are. What I was saying is that if someone wants to say that cab A is not capable of...etc etc, it has to own one, test it, measure it, and then he can come back to me. Or, if it has been claimed something unfair and untrue by the manufacturer, I wanted to know.

It puts the lotion on its skin.

Seriously, I agree with you for the most part. My intent was to say that skepticism is a basic tool of science. Without it, would not the first version of any theory simply be accepted as fact? And yes. In the fields of science, engineering and technology, there is no room for preconception.

Someone, I don't recall who, during this thread made, what is in my opinion, a disparaging comment related to charts and graphs. I took that to be a comment about how science shrouds itself in math and statistics to intentionally keep the common people out. Certainly you, better than most of us, understand the need for all of the data that is compiled during testing of any type.

So other than what appears to be a slight difference in how we each think skepticism fits, or does not fit, within the sciences, we seem to be pretty much on the same page.

ps I applaud your accomplishments and contributions to the medical sciences.
If it were not for folks like you, I probably would not be able to carry out this conversation.

 

[sratas]

It puts the lotion on its skin.

Seriously, I agree with you for the most part. My intent was to say that skepticism is a basic tool of science. Without it, would not the first version of any theory simply be accepted as fact? And yes. In the fields of science, engineering and technology, there is no room for preconception.

Someone, I don't recall who, during this thread made, what is in my opinion, a disparaging comment related to charts and graphs. I took that to be a comment about how science shrouds itself in math and statistics to intentionally keep the common people out. Certainly you, better than most of us, understand the need for all of the data that is compiled during testing of any type.

So other than what appears to be a slight difference in how we each think skepticism fits, or does not fit, within the sciences, we seem to be pretty much on the same page.

ps I applaud your accomplishments and contributions to the medical sciences.
If it were not for folks like you, I probably would not be able to carry out this conversation.

thanks mate, sometimes words on the internet are easy to misunderstand. Wish you the very best.

 

[Passinwind]

What I was saying is that if someone wants to say that cab A is not capable of...etc etc, it has to own one, test it, measure it, and then he can come back to me. Or, if it has been claimed something unfair and untrue by the manufacturer, I wanted to know.

In this case the onus on a third party of having to buy one or more cabs and destroy it/them in order to verify the power handling claims is pretty high, so perhaps it's more reasonable to ask the manufacturer to specify their test protocol a bit more explicitly? Link Removed

AFAIK, Agedhorse is bound by the TB CUP agreement to avoid negative comments about other manufacturers, so I don't think it's really fair to ask him to call out any specific case.

 

[sratas]

In this case the onus on a third party of having to buy one or more cabs and destroy it/them in order to verify the power handling claims is pretty high, so perhaps it's more reasonable to ask the manufacturer to specify their test protocol a bit more explicitly? Link Removed

AFAIK, Agedhorse is bound by the TB CUP agreement to avoid negative comments about other manufacturers, so I don't think it's really fair to ask him to call out any specific case.

good call passinwind. It seems reasonable to ask the manufacturer, if he wants to chime in, we are here to know, with legit curiosity and open mind. I wanna know for sure.

ad far as TB CUP, I was surprised to read that agedhorse was saying that...in fact, even without law restrictions, I find unfair to say the barefaced can't do this and that and when I consider that he hasn't even touched the cab, it becomes even more so. He is, somehow, a barefaced commercial contender.

Anyway, I have not married barefaced, nor Mesa or others. I never understood when a customer falls in love with a model or a brand till becoming simply a fan, so I'm more than prone to changing my ideas and mind if someone proofs the contrary. This is science, a truth keeps its value until it is scientifically proven the contrary, and this works in both directions.

 

[HaphAsSard]

I was surprised to read that agedhorse was saying that

Saying what? And please quote specific passages.

 

[sratas]

Saying what? And please quote specific passages.

from a post (previous page of thread), talking about the BB2:


"I am generalizing when claims are made that simply can not be realized no matter how good the intention, but violate the laws of physics. It is simply not possible to take the combination of variables available to come to that conclusion....


So is the BB2 an 800 watt speaker or a 600 watt speaker or a 500 (or 400) watt speaker and what units of measure?....


It's all in the details my friend, perhaps an essential detail is incorrect? That's what it looks like to me...."


Nothing bad, but these doubts have to be cleared. I mean, both ways.

 

[sratas]

anyway...till we hear the other bell, we cannot keep this path, it's sad.

we can try to talk about 12 cabs with high power handling, and keep the thread less brand oriented instead

 

[HaphAsSard]

from a post (previous page of thread), talking about the BB2:


"I am generalizing when claims are made that simply can not be realized no matter how good the intention, but violate the laws of physics. It is simply not possible to take the combination of variables available to come to that conclusion....


So is the BB2 an 800 watt speaker or a 600 watt speaker or a 500 (or 400) watt speaker and what units of measure?....


It's all in the details my friend, perhaps an essential detail is incorrect? That's what it looks like to me...."

And your problem with these quotes is what exactly?

Nothing bad, but these doubts have to be cleared. I mean, both ways.

His general comment about claims that must abide the laws of physics is simple common sense. Furthermore, nothing specific he said is in contrast with what is stated on the Barefaced website, as far as I've been able to determine. If you have concluded otherwise, by all means point out how. And if you have further questions enquire with the manufacturer, not third parties.