Would you be interested in approx. 25lb 4x10 or 16lb 2x10 (sound in the vein of a Ber

[Mike Arnopol]

Originally Posted by dawind99

Mike, not bashing at all! Great observations, and you are obviously familiar with being told you what you can't do Much appreciated. I never know when I begin to develop a new idea whether it will work as designed or not. I do a lot of "mental chess" before going forward to the build. I'm sure you do as well.
Here is where I've landed in 2012 regarding Xmax:

Xmax is a number provided by speaker manufacturers as part of the Thiele Small parameters for enclosure designers to plug in to whichever "Design " program they are using. (all based on Thiele Small parameters) for general reference. I see a lot of folks hanging on to Thiele Small parameters as if they were carried down on tablets from the mountain and not accepting them for what they are: brilliant formulas from two Australian gentleman devoted to understanding and defining propagation of sound. They are electromechanical formulas, and therefore need specific definable measurements either provided by the speaker manufacturer(not always correct), or gathered by the designer/builder. Compliance provided by new cone/surround materials available, in my opinion, has had a significant effect on how these parameters should be used/viewed and their relativity, specifically the relationship between Q (ts,ms,es,) and Xmax. The new surround, cone, and spyder, materials allow the same performance with a lower Xmax. Longer Xmax is longer travel time, longer travel=slower response, analogies; think Bruce Lee, bigger bungee cord....as ridiculous as it sounds. The Xmax does not make the wave travel further or faster, it was just a mechanical limit assigned to the driver. So, believe or at least consider that with todays materials a lower Xmax could indeed be more favorable.

That said I use a combination of modelling programs and what I have always done; stuck my head in the cab and adjust tuning.

respect,
David Luke

Of course xmax doesn't tell everything. What it does is give an idea of how much air a speaker can move. When deciding on drivers I find that VD (xmax or excursion times cone area) gives me a relatively good idea of how much air a speaker can move. And low frequencies are all about moving air. Other factors are important---Qts gives me an idea of the quality of bass but I find that xmax gives me a good idea of the quantity of bass. I have found that this has behaved very consistently. And the speed of the speakers response is largely dictated by the mass to be moved x the power of the motor. If the strength of the motor is increased the "speed" of a driver can be maintained. With the new neo drivers the strength of the motor can be increased dramatically without paying the price in weight.

So---my experience has been that a driver with an xmax of 8mm will go much louder than a driver (same diameter) with an xmax of 4 mm. The amount of air moved will be roughly the equivalent of two of the 4mm drivers. Not talking about quality of sound, but quantity.

Which is why the Kappalites seem to be the choice of many contemporary speaker designers.

I'm super open to discussing why this is not the case---just speaking from personal experience.

[davidjbass]

I just played one of the REV Sound RS410t cabs and I have to say it's hands down one of the best sounding and most lightweight 410's I have ever played. It's so light that I can pick it up in one hand and carry it in comfort. It has a nice full range sound and it's loud. The tweeter design is very comfortable to the ear. And I am not a tweeter kinda guy. Construction is top notch and it fits in my small car with no problem.

I am not a techno person and don't really get into the specs of design and why something sounds so good. I just play and if I like what I hear from equipment I try I own it. So I am about to be a proud owner of one of these cabs.

My advice. Don't get so technical. Let your ears and back do the judging.

[DukeLeJeune]

Originally Posted by dawind99

Compliance provided by new cone/surround materials available, in my opinion, has had a significant effect on how these parameters should be used/viewed and their relativity, specifically the relationship between Q (ts,ms,es,) and Xmax. The new surround, cone, and spyder, materials allow the same performance with a lower Xmax.

A good motor and good suspension system will enable a cone to exceed x-max "gracefully"; that is, the onset of fartout can be delayed somewhat. However the region of best performance is still within the region of linear excursion.

Originally Posted by dawind99

Longer Xmax is longer travel time, longer travel=slower response, analogies; think Bruce Lee, bigger bungee cord....as ridiculous as it sounds.

Lower frequency = longer travel time. X-max has nothing to do with "travel time".

If we want to move the same amount of air with less excursion, we need to increase cone area (or otherwise increase the acoustic radiation resistance - but that's another topic).

Originally Posted by dawind99

The Xmax does not make the wave travel further or faster, it was just a mechanical limit assigned to the driver. So, believe or at least consider that with todays materials a lower Xmax could indeed be more favorable.

Agreed, x-max is a mechanical limit (though usually a "soft" one), indicating the onset of non-linear cone movement. Beyond x-max, the amplitidue of the output no longer corresponds to the amplitude of the input. Subjectively, it starts out as a loss of impact, a compression of peaks, and eventually fartout sets in.

When we're talking about equal-area cones that have a ballpark 2:1 difference in x-max (such as Kappalite LF's vs most other bass guitar woofers), we're talking about a 4:1 difference in power handling before fartout sets in, assuming the same efficiency and equivalent motors and suspension systems. So greater x-max pays significant dividends in the real world.

[dawind99]

Originally Posted by Mike Arnopol

Of course xmax doesn't tell everything. What it does is give an idea of how much air a speaker can move. When deciding on drivers I find that VD (xmax or excursion times cone area) gives me a relatively good idea of how much air a speaker can move. And low frequencies are all about moving air. Other factors are important---Qts gives me an idea of the quality of bass but I find that xmax gives me a good idea of the quantity of bass. I have found that this has behaved very consistently. And the speed of the speakers response is largely dictated by the mass to be moved x the power of the motor. If the strength of the motor is increased the "speed" of a driver can be maintained. With the new neo drivers the strength of the motor can be increased dramatically without paying the price in weight.

So---my experience has been that a driver with an xmax of 8mm will go much louder than a driver (same diameter) with an xmax of 4 mm. The amount of air moved will be roughly the equivalent of two of the 4mm drivers. Not talking about quality of sound, but quantity.

Which is why the Kappalites seem to be the choice of many contemporary speaker designers.

I'm super open to discussing why this is not the case---just speaking from personal experience.

Mike, Really appreciate your interest and open mindedness. I think I might not have been as clear as I wanted to be relative to Xmax not being as valid as it use to be. The new drivers with lower or even equal cone mass due to cone/surround materials and the strength and tortional ridgidity they're afforded allow them to move the air with lower cone travel and recover more quickly. Once the wave is propagated the air is moving. The ability for the cone to not have to travel so far before recovering gives it faster transient response. All the driver companies out there are making excellent motors. We just chose to use the Celestion because of my history with them, the Kevlar impregnated cone, and that it works for us. I absolutely love the 12s JBL is using in their SRX series cabs but the fact that they like to see 800 watts to get pumping, and @ well over 400. a driver none of my musician friends or my son's friends in High School would ever be able to afford a cab using them. I need to make a profit, but I want my cabs to be accessible to a "starting out" player/teenager and have the sound quality and durability for my pro friends. That was always part of my mission and remains most important. As a kid growing up playing you probably went through the same thing I did. We played what we had and could afford. If I had a guitar with strings under 3/8 of an inch off the fretboard and a decent amp I would have been where I am as a player a lot sooner. No regrets; just saying.

Regarding the Xmax thing I think a new thread for the topic would be a good idea, and maybe we could get some more folks that are as willing to be open to new possibilities as you are to brainstorm. I think that would be great.

respect,
David Luke

[Roadkill]

Thanks Mike and Duke for injecting a bit of reality into this conversation - but that said I really did enjoy the sound of those Celestions in the Rev Sound cabs, and they are well built and light. I hope this silliness about a 25lb 4x10 or a 16lb 2x10 doesn't cause anyone not to give their "real world light" cabs a serious look. If I didn't already have a pair of SVT210AV's and a pair of 212MBE's I'd be seriously GASsin' after some .

And Dave, your understanding of cone motion isn't. Hope you weren't listening to BF up in NH ?

[Balog]

Originally Posted by dawind99

I am interested in participating and made the trip to the GTG in Hampton, CT. the prototype was there. It was a great get together of open minded, cool individuals with a common bond. BASS. I drove down in the am from northern NH after playing the night before. So glad I did. People played, listened, shared ideas, and made some new friends. So, yes, I'd love to participate....kind of a sound geek, not incredibly social, and definitely what's on/in my mind comes out uncolored. I've been building/designing for 35 years with large companies and my own.
I've been playing professionally from age 14 and still play 3 nights a week. My first job out of college was with Microwave associates in Burlington, MA where I was an R&D Engineer assigned to HS switching modules that were failing in the bellies of F4 Phantom IIs, and F14A Tomcats and they were being taken down by SAMs. The other engineers on my team, who were much older, "seasoned" and very capable looked at everything but the simplest: the solder joints were not bonding to the chips.
I found that, hopefully saved some planes and pilots and learned a lesson I've held on to: If it doesn't work, see if it's plugged in before you take the back off.

I love sharing ideas, talking about what I'm doing and would appreciate folks to bounce ideas off. Please feel free to ask anything and I will answer best I can. I remain in it for the long haul.

respect,
David Luke
Revsound

Hi, thanks for commenting. I appreciate you taking the time, certainly sounds like you have a full schedule.

The only question I have is pretty simple: do you have (or anticipate having) cabs that will meet the weight goals set out in the OP ie 16lb 2x10 and 24lb 4x10? If so, how does their performance compare to other, heavier cabs? Thanks.

[Mike Arnopol]

Originally Posted by dawind99

Mike, Really appreciate your interest and open mindedness. I think I might not have been as clear as I wanted to be relative to Xmax not being as valid as it use to be. The new drivers with lower or even equal cone mass due to cone/surround materials and the strength and tortional ridgidity they're afforded allow them to move the air with lower cone travel and recover more quickly. Once the wave is propagated the air is moving. The ability for the cone to not have to travel so far before recovering gives it faster transient response. All the driver companies out there are making excellent motors. We just chose to use the Celestion because of my history with them, the Kevlar impregnated cone, and that it works for us. I absolutely love the 12s JBL is using in their SRX series cabs but the fact that they like to see 800 watts to get pumping, and @ well over 400. a driver none of my musician friends or my son's friends in High School would ever be able to afford a cab using them. I need to make a profit, but I want my cabs to be accessible to a "starting out" player/teenager and have the sound quality and durability for my pro friends. That was always part of my mission and remains most important. As a kid growing up playing you probably went through the same thing I did. We played what we had and could afford. If I had a guitar with strings under 3/8 of an inch off the fretboard and a decent amp I would have been where I am as a player a lot sooner. No regrets; just sayin

I guess we'll save the xmax discussion for another thread---it just differs from my knowledge/experience base as I've said.

I think that it's very cool to offer a higher end cab that is financially accessible for younger players. It's nice for them to have an option other than the stuff at Guitar Center. That is one thing that bums me out about my cabs---they're expensive and it limits the amount of players who can afford them. Hell---I can't afford them!

The reason I started making cabinets when I was 16 (before the advent of electricity) was that I couldn't afford the ones I wanted. So I reverse engineered an Acoustic 360! That's a lot of miters for a 16 year old with a Skil saw!

[dawind99]

Originally Posted by Balog

Hi, thanks for commenting. I appreciate you taking the time, certainly sounds like you have a full schedule.

The only question I have is pretty simple: do you have (or anticipate having) cabs that will meet the weight goals set out in the OP ie 16lb 2x10 and 24lb 4x10? If so, how does their performance compare to other, heavier cabs? Thanks.

I don't know yet. I expect the new RS210 fusion to come in at close to 20, perhaps under if all goes as planned. I'm relatively confident it will. I've changed the construction technique. I surf (not well but I love it) and the original design was using monocoque construction technique without fiberglas web or epoxy based resin, which although are strong are not pleasant to work with and are pretty heavy. I sourced a polymer that works great on a flat surface, has a density of 2025lbs/in and moisture cures. Unfortunately it's not time effective and I've move id another direction. If anyone is interested and already has skills in surfboard shaping I would be happy to send you a sample of what the polymer will do and explain how I got where I was. I am just headed in a direction that is more "shop friendly" for us.

thanks Michael,
David Luke

[DukeLeJeune]

Originally Posted by dawind99

The new drivers with lower or even equal cone mass due to cone/surround materials and the strength and tortional ridgidity they're afforded allow them to move the air with lower cone travel...

Okay, this is where you lose me.

I hope you don't mind my asking, but would you please explain how improved cone rigidty from new materials makes a difference in the cone excursion required to reach a particular SPL down in the low frequency region, when conventional cones are operating pistonically in that region already.

Your post goes on to claim improved transient response due to the cone not having to move as far, but this of course depends on your premise that new cone/surround materials result in less excursion being needed to "move the air". I would like to see that premise explained and established first, if you don't mind.

Thanks.

[davidjbass]

A pic of me with Basswave's RS410t. I got one of the same coming my way in a couple of weeks. Can't wait. Thanks for letting me borrow it Tony. You might have to pry it from my hands to get it back.

[dawind99]

Originally Posted by DukeLeJeune

Okay, this is where you lose me.

I hope you don't mind my asking, but would you please explain how improved cone rigidty from new materials makes a difference in the cone excursion required to reach a particular SPL down in the low frequency region, when conventional cones are operating pistonically in that region already.

Your post goes on to claim improved transient response due to the cone not having to move as far, but this of course depends on your premise that new cone/surround materials result in less excursion being needed to "move the air". I would like to see that premise explained and established first, if you don't mind.

Thanks.

Cone type drivers move "pistonicaly", that's a given. If a cone was made out of a dishrag stretched tight would it move the same air a piece of waxed paper would? Does a 20 year old "fatigued" JBLD130 move as much air as a 10 year old E140? Would a Kevlar impregnated cone move as much air as a traditional paper cone?
I know the first 2 answers. The third, I don't know empirically, but I suspect the Kevlar impregnated (and from what I have experienced using them live) indeed move as much air creating spl equal to or beyond their traditional counterparts of the same wattage ratings. how far does a cone have to move to move air? It just needs to move. "The lower the frequency, the further the cone needs to travel to impart a given amount of acoustic energy to the air. The cone excursion is inversely proportional to the square (approximately) of the frequency."
I'm not sure this is a truth. What do you think Duke? And, I humbly ask this question to someone I hope is open minded.
I still have some contacts at MIT and I will try and get someone to post or at least send us their opinion.

You might get a kick out of this: search Woody Norris and you can see where the possibilities are going.

I'm at the shop all day tomorrow and playing tomorrow night. I love discussion/debate but only if it moves forward. Please feel free to give me a call. 603.651.9800

respect,
David Luke

[bobcruz]

A pic of me with Basswave's RS410t. I got one of the same coming my way in a couple of weeks. Can't wait. Thanks for letting me borrow it Tony. You might have to pry it from my hands to get it back.

I dig the subtle, almost invisible logo on the grill. That's one I wouldn't feel like I had to paint over to remove the SHOUTING LOGO syndrome that could distract an audience from my mediocre playing!

[dawind99]

Originally Posted by Roadkill

Thanks Mike and Duke for injecting a bit of reality into this conversation - but that said I really did enjoy the sound of those Celestions in the Rev Sound cabs, and they are well built and light. I hope this silliness about a 25lb 4x10 or a 16lb 2x10 doesn't cause anyone not to give their "real world light" cabs a serious look. If I didn't already have a pair of SVT210AV's and a pair of 212MBE's I'd be seriously GASsin' after some .

And Dave, your understanding of cone motion isn't. Hope you weren't listening to BF up in NH ?

Reality is what you accept It's mine and rather than remain static and stay inside because the weatherman said it's raining I'm going outside to see if it's really snowing And, Mike and Duke Rock!! Open minds keep us from becoming dinosaurs.

re BF: No man, mostly listen to the wind up here. By the way what's BF?

[fdeck]

Originally Posted by dawind99

how far does a cone have to move to move air? It just needs to move. "The lower the frequency, the further the cone needs to travel to impart a given amount of acoustic energy to the air. The cone excursion is inversely proportional to the square (approximately) of the frequency."
I'm not sure this is a truth. What do you think Duke? And, I humbly ask this question to someone I hope is open minded.

This might help:

http://personalpages.tds.net/~fdeck/bass/speaker.pdf

The reason for the relationship between excursion and the square of the frequency is that the amplitude of the sound pressure wave is proportional to the volume acceleration of the cone.

Of course my derivation only applies to the pistonic realm, but it would take a profound amount of cone flexing to cause an audible deviation from pistonic behavior at low frequencies. And Xmax doesn't matter at high frequencies because of the same relationship between excursion and frequency.

By way of disclaimer, I'm quite open minded. I've experienced having a number of my misconceptions about the inner workings of gear overturned as I gain a better and better understanding.

[Roadkill]

Originally Posted by dawind99

Open minds keep us from becoming dinosaurs.

Yup - while acoustics tells us many things with certainty psycho-acoustics tells us other things that few with a solid understanding of the former understand. Reproducing the fundamental isn't as important or desirable as some here go on about. And running drivers past their xmax generates harmonics that make the ear perceive those missing fundamentals and makes the cab sound much louder than it really is. I'd postulate that the lower xmax of the Celestions is why they sound so powerful . http://en.wikipedia.org/wiki/Psychoacoustics

By the way what's BF?

http://www.billfitzmaurice.com

[DukeLeJeune]

Originally Posted by dawind99

I don't know empirically, but I suspect the Kevlar impregnated (and from what I have experienced using them live) indeed move as much air creating spl equal to or beyond their traditional counterparts of the same wattage ratings.

Equal to its traditional counterparts, I would easily believe. Moving more air than its counterparts without actually physically moving farther, that is what I question. I don't doubt that you hear a difference, I just don't think it's because the new cone material somehow moves more air without actually moving farther, which is what I think you've been saying. If I've misunderstood you, my apologies, and please correct me.

Originally Posted by dawind99

"The lower the frequency, the further the cone needs to travel to impart a given amount of acoustic energy to the air. The cone excursion is inversely proportional to the square (approximately) of the frequency."
I'm not sure this is a truth. What do you think Duke? And, I humbly ask this question to someone I hope is open minded.

Likewise, I hope you are open minded to the possibility of cone area x excursion = amount of air moved = acoustic energy at a given frequency, and that beyond the rigid cone stipulation the material it's made out of doesn't have a bearing on this relationship, assuming competent design.

To answer your question, yes I think the statement you quoted is correct for a purely direct-radiator loudspeaker (it's a little more complicated for a ported box in part because some of the air movement is contributed by the port), but I would have left out the word "approximately". Why are you "not sure this is a truth"?

Originally Posted by dawind99

You might get a kick out of this: search Woody Norris and you can see where the possibilities are going.

Woody Norris gave a TED presentation a couple of years ago where he demonstrated a device that uses an ultrasonic speaker to "beam" sound very precisely. Since the emitting diaphram is quite large relative to the wavelengths reproduced, the thing beams like a laser. I think it works something like this: Two ultrasonic signals are used, one being a version of the original audio signal, and the other is the carrier wave. The "beat" between these two waves produces both a sum and a difference signal, and the difference signal is down in the audio region, so we can hear it. Sorry for the off-topic, but you mentioned Norris, and yes he does some cool stuff.

[Mike Arnopol]

Originally Posted by Roadkill

Yup - while acoustics tells us many things with certainty psycho-acoustics tells us other things that few with a solid understanding of the former understand. Reproducing the fundamental isn't as important or desirable as some here go on about. And running drivers past their xmax generates harmonics that make the ear perceive those missing fundamentals and makes the cab sound much louder than it really is. I'd postulate that the lower xmax of the Celestions is why they sound so powerful . http://en.wikipedia.org/wiki/Psychoacousticshttp://www.billfitzmaurice.com

It's absolutely true that the fundamental is not as important as some think. But only the lowest fundamentals. Which is why Fdeck's HPF works so well. Which is why Dukes goal was to catch the first harmonic of the B string as a design goal. Even with a low B string we don't need the fundamental. The psycho-acoustics allow the ear to fill in the information. But we do need relatively flat to 60hz. (we need the first harmonic)And 60hz at a high volume requires a lot of xmax. Running drivers past their xmax is not a very good idea. I'll let Duke and Francis explain more clearly. The driver won't sound more powerful. It will exhibit less low end control. The entire frequency range will suffer. And there isn't a whole lot of room between xmax and hitting the back plate.

Most people associate huge low end with mid bass frequencies. Which is why people think that an SVT bottom has huge bass. It doesn't. It has huge midbass. When you hear all of that bass coming from those lovely urban automobiles it's all above 100 hz. So---you can get the illusion of a lot of bass from a speaker with little output below 100hz. But these days bass sound has evolved to intelligently utilize the octave below 100hz. Or maybe not-so-intelligently in many cases.

I've never heard David's cabs but I don't doubt that they sound really nice. It's just that if we're going to use technical terms to describe the function of our speakers that we can come to an agreement as how to describe them in technical terms that are consistent with accepted knowledge.

I'm involved in a project (I won't go into details here) where the technology is pretty new and different. And I made some pretty absurd-sounding claims. And I was raked over the coals to back them up. Which (while some people were pretty rude and confrontational) was totally fair.

I'm always trying to learn--which is why this thread intrigued me. I do wish that the thread title was changed--it's pretty misleading and demeans the integrity of what I'm sure are very nice sounding cabinets. My ego is invested in my playing---not my cabs. So if someone comes up with something new and super-cool--I couldn't be more excited.

[Tactician]

I think we are more in agreement than discord. As a guitar and bass teacher I find I'm often coaching students who are in bands, in how to get an acceptable sound. It comes down to basically, what sounds great in the bedroom will often mix badly into a live band. You can hear plenty of sub and fundementals down below 100hz solo in practice - but that doesn't carry very well in a live band unless you've really spent a lot on amps and cabs to get that across to an audience. On the other hand, clunky, top end bass may sound great when practicing a solo - but how often is the average bass player do solos? So that top end sound sounds like the guitarist riffing on his E and A strings. (Think using a normal guitar through an octaver.)

In the end it comes down to what it sounds like within a band mix. For the average player they are knocking it out in the 100hz to 400hz range with harmonics loaded on top of that. That's why those old Marshall cabs from my early years in the 60's sounded the way they did - speakers that didn't go very low, cabinets that were as small as they could be for 4x12s, and sealed backs. There wasn't any real design criteria - just - was it acceptable? Since there was nothing else anything like them, they sold.

But there's the rub. We got used to heavy big cabs and associate them with good sound. As soon as anyone comes along with a smaller / lighter cab, they are up against tradition. I bet the marketing guys at Phil Jones fight this every day.

I'm as sure as You Dave L, that a light powerrful cab is possible. Bill Fitzmaurice is pretty much there with those Jack Lite cabs made from light ply and lots of braced curve sections. I can imagine a cab made from 1/4" ply, with a load of inner bracing doing a great job. But the bottom line is would people buy them when they seem so light, LOOK like they are lightly built AND construction costs 3x what a straight box costs.

I'd be interested in seeing what the sales numbers and trends are for all commercially available cabs. Is Phil Jones gaining market share? Are traditional heavy cabs holding their own? Is the trend - cabs are getting smaller? I suspect 85%+ of the market is budget buys for learners up to semi pros - and all those guys buy cheap, Asian built, simple box cabs.

That doesn't mean the isn't a big market. It means that market is niche and specialist. If you know how to get to those guys (route to market) you have a business proposition. Ampast business contact of mine was Ivor Teifenbrum, the owner of Linn Products - specialist and very top end Hi Fi equipment. His view was that there will always be a small group of people who want the best - the absolute best you can buy. Those in turn divide down into many groups, such as the super rich who'll buy because its the best, and the fanatic who doesn't have much money, but its his 'thing' to have the best. (like Fararri owners - the rich and/or the obsessed).

If you build it you'll need a route to the market and a way of targetting the 'must-have-it' buyer. And I guess talking about it here is a great start.

[basswave]

Originally Posted by davidjbass

A pic of me with Basswave's RS410t. I got one of the same coming my way in a couple of weeks. Can't wait. Thanks for letting me borrow it Tony. You might have to pry it from my hands to get it back.

David J
I'm stoked that you like the cabinet...
Like David J, I'm player that does a lot of different styles
and I'm not technicial audio person like some of the folks on here who started taking this off topic a bit.

All I know is what sounds good to Me, my Bandmates, Artists, Producers and last but not least the muscial director.
I have been using the RS410T and RS210 for the following type of gigs, some of this with no PA support.

-Theater with muptiple percussion
-Rock/Funk
-Country pop
-Piano Jazz trio

No complaints for anyone.

For those who think the 410 or 210s are outdated.

Well I don't see Strats, Les Pauls, P & J basses going way of the dodo.

If you look at light night TV what do you see all the bass players playing (Sadowsky, an updated J bass sytle instrument).

Thats how I look at Revsound cabinets.

Un updated version of 410s 210s ect...That work.

Back on topic. The Fusion has the possibility of taking it to the next level.

[Roadkill]

Originally Posted by Mike Arnopol

Running drivers past their xmax is not a very good idea. I'll let Duke and Francis explain more clearly. The driver won't sound more powerful. It will exhibit less low end control. The entire frequency range will suffer.

There's a whole lot of live sound guys running 1500+ watts into each 18 because according to them they don't "come alive" below that. As you probably know there is only a theoretical 3db advantage over running 750w but there is a large apparent difference in output. I attribute this to the harmonics generated by exceeding xmax that the ear is much more sensitive to. What's your theory?

And there isn't a whole lot of room between xmax and hitting the back plate.

Most drivers I've looked at have a 2:1 ratio (AKA 6db) between xmax and xlim. And - as you know - the non linearity past xmax increases that substantially. That means a driver that reaches xmax at 200w at 60Hz needs 800-1200 watts to "fart out". OTOH you're right in that many drivers don't have a suspension to handle constant excursions past xmax and will have a dramatic shift downward of their fs over time (AKA get "flabby") and the cab will no longer be "tuned" to them. Many of the guys I know running big power to their subs swap them out yearly.

[...]if we're going to use technical terms to describe the function of our speakers that we can come to an agreement as how to describe them in technical terms that are consistent with accepted knowledge.

+1000

I'm involved in a project (I won't go into details here) where the technology is pretty new and different.

Hey, can you shoot me a link either here or in PM? Thanks!

I do wish that the thread title was changed--it's pretty misleading and demeans the integrity of what I'm sure are very nice sounding cabinets.

Exactly what I said in an earlier post .

BTW in the interest of full disclosure I'm an EE "In Real Life (tm)" but as said above I do try to understand why folks say the things they do that apparently contradict the science. When all is said and done "If it sounds good it is good" .