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

[Calaverasgrande]

Originally Posted by dawind99

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.

respect,
David Luke
Revsound

In IT we call that the physical layer. Is it plugged in?

[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.

Duke, As I stated before, I think all the speaker manufacturers are making excellent products. We use Celestions because of my long history with the company and they fit the sound I was looking for. It’s up to you to find your “flavor”. I put together a few observations, and you can plug the numbers into the equations below for whatever speakers you might want to compare. I just threw out that the Celestions, move air and are fast. I postulated that it was due to cone materials/weight/strength and actually a stronger magnet perhaps. It is a combination of all these. This is what brought me there. And, at the end I decided for me: Xmax matters, and it doesn’t matter.

My observations:
The Celestion has a lower Xmax . It also has a Vas that is half that of, for example, the Eminence 10 Kappalite 3010 31.5l vs 62.4 indicating a stiffer cone assembly, a low Qts, and a lighter cone assembly. I suggest this is Celestions solution for a driver that functions as well with lower Xmax.
Acceleration is a critical component of creating SPL. The higher the rate of acceleration, the more pressure that can be created.

Newtons Second Law of motion:
F=m x a
The net force of an object is equal to the product of it's mass and it's rate of acceleration. F=m x a
Extrapolate:

A=F/m
Measurement of the force of a driver requires these (3) measurements:

1. BL - the combination of the magnetic field strength (B ) and the length of the voice coil in the gap (L)
2. I - the level of input current
3.) MMS=the weight of the cone assembly plus the ‘driver radiation mass load(the weight of the air the cone will have to push ie. Vd)

I suspect you will question using MMS as a substitute for M mass, but It is an equivalent in this situation..
Taking that information (BL and I) we have a driver applicable equation:

A =(BLx I)/m

From this we can calculate that:
1.) a + change in the magnetic field strength (B ) or the length of the voice coil (L) will increase the rate of acceleration (which the Celestion driver BL compared to (3) Eminence neo 10s compares at a factor of 1.5/1)
2. ) Increase of input current (I) will increase the rate of acceleration
3.) Increasing the mass of the driver will decrease the rate of acceleration
naturally, the inverse of these conclusions hold true as well. For example, if you decrease the moving mass of the driver, the rate of acceleration will increase.
Xmax is and is not relevant to SPL. But, they interact in such a fashion that requires you to choose what you want to sacrifice for what you gain.
More Xmax…easy right; longer voice coil, oh but wait; more mass, well that slows down things doesn’t it. A loud driver exhibits High BL, high power handling, low moving mass.
But, it’s the combination of these qualities/specs that give you the speaker with a “voice” that you want. We can postulate until the dirt’s on us. I would like talking about new technology, new ideas, and “what if’s” and “maybe this would work” even when the numbers say they won’t.

There is a sweet spot in choosing a driver for your enclosure, that’s my point I guess. Please know that we’re not having a “pistonic” contest here. I’m as fascinated as you in why you choose a driver and why one may be a better fit even though the traditional specs that you usually look for when choosing ( Xmax being one) don’t size up to another So, that’s my conclusion: oblique yet true.
A loud driver exhibits High BL, high power handling, low moving mass.
But, it’s the combination of these that give you the speaker with a “voice” that you want. We can postulate until the dirt’s on us. I would really getting a thread started about new technology, new ideas, and “what if’s” and “maybe this would work” even when the numbers say they won’t. Maybe it’s the musician side of me at war with the engineer. There's a lot going on out there.

Respect,
David Luke

[DukeLeJeune]

Hi David,

Just for the sake of clarity and continuity, let me mention again the statement of yours that I disagree with:

"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..."

My position is that, assuming competent woofer design and pistonic cone behavior, SPL at low frequencies is strictly a function of cone area times excursion. Improved materials simply do not allow a woofer to move more air with less cone travel.

Originally Posted by dawind99

Newtons Second Law of motion:
F=m x a
The net force of an object is equal to the product of it's mass and it's rate of acceleration. F=m x a
Extrapolate:

A=F/m
Measurement of the force of a driver requires these (3) measurements:

1. BL - the combination of the magnetic field strength (B ) and the length of the voice coil in the gap (L)
2. I - the level of input current
3.) MMS=the weight of the cone assembly plus the ‘driver radiation mass load(the weight of the air the cone will have to push ie. Vd)

A =(BLx I)/m

From this we can calculate that:
1.) a + change in the magnetic field strength (B ) or the length of the voice coil (L) will increase the rate of acceleration (which the Celestion driver BL compared to (3) Eminence neo 10s compares at a factor of 1.5/1)
2. ) Increase of input current (I) will increase the rate of acceleration
3.) Increasing the mass of the driver will decrease the rate of acceleration
naturally, the inverse of these conclusions hold true as well. For example, if you decrease the moving mass of the driver, the rate of acceleration will increase.

It is true that the lighter the cone and/or stronger the magnet, the more acceleration that can be applied to the cone... but that's irrelevant to the topic at hand. Let me explain:

Where does acceleration become a limiting factor? Down in the bass region? No... up at the top-end of the driver's range. Heavy cones and long, heavy voice coils don't go up as high as light cones and short, lightweight voice coils (inductance is a factor too). We see where acceleration becomes the limiting factor in the roll-off at the top of the driver's frequency response curve.

Originally Posted by dawind99

Xmax is and is not relevant to SPL. But, they interact in such a fashion that requires you to choose what you want to sacrifice for what you gain.
More Xmax…easy right; longer voice coil, oh but wait; more mass, well that slows down things doesn’t it. A loud driver exhibits High BL, high power handling, low moving mass.
But, it’s the combination of these qualities/specs that give you the speaker with a “voice” that you want. We can postulate until the dirt’s on us. I would like talking about new technology, new ideas, and “what if’s” and “maybe this would work” even when the numbers say they won’t.

There is a sweet spot in choosing a driver for your enclosure, that’s my point I guess. Please know that we’re not having a “pistonic” contest here. I’m as fascinated as you in why you choose a driver and why one may be a better fit even though the traditional specs that you usually look for when choosing ( Xmax being one) don’t size up to another So, that’s my conclusion: oblique yet true.
A loud driver exhibits High BL, high power handling, low moving mass.
But, it’s the combination of these that give you the speaker with a “voice” that you want. We can postulate until the dirt’s on us. I would really getting a thread started about new technology, new ideas, and “what if’s” and “maybe this would work” even when the numbers say they won’t. Maybe it’s the musician side of me at war with the engineer. There's a lot going on out there.

Of course X-max isn't the only thing that matters, otherwise we'd all be using subwoofer drivers.

Improved cone/surround materials do not somehow increase the linear air-moving capabilty of a speaker at low frequencies unless x-max is also increased (and yes there are different ways of measuring x-max; the Klippel curve gives the most apples-to-apples comparison). As I stated before, the amount of air that a woofer moves is a function of cone area times excursion. Improved materials may offer improved performance in other areas, but do not allow them to somehow "move the air with lower cone travel". The way to do that is, use a bigger cone. Or horn load it, a la Bill Fitzmaurice.

[Tactician]

Here in the UK people are way more covered for patent and copyright infringemnets than they realise. However not all countries and companies respect the law and you can find youself taking onthe might of a nation that doesn't respect the law - you know who I mean. Look at what happened to the Ebtech Swiss Army cable tester - got cloned by at least two products and completely outsold by these products coming in at 1/4 the price.

So we completely understand your reticence to devulge info - but once its out there don't expect the patents to work with foreign imports. Its more about getting outstanding product out there, building a rep, and building a relationship with your target niche.

[Roadkill]

BTW the drivers in my SVT210AV cabs have an xmax of 3.2mm and the cabs start to roll off at 150Hz - can't possibly sound good, eh?
http://www.eminence.com/pdf/Alpha_10A.pdf

[Chef]

^^^I love those lil cabs!

[Mike Arnopol]

The point is not that lower xmax drivers don't sound good---in some cases they may sound better---the point that's trying to be made is that their dynamic range and low end are limited in comparison to higher xmax drivers Which is why a 410 with higher xmax drivers can go as loud and possibly lower than an SVT. If you are using a lower xmax driver, especially in a sealed box you have to use a lot of them to get that huge sound. And I don't think that any one here is going to say that an SVT cab isn't one of the gold standards of bass tone. For some.

Some of the best bass sounds that I've gotten in my life have been with cool old speakers with a very low xmax. They just didn't go loud or low.

The discussion here about xmax was started by David's claims that SPL in the low end was not necessarily determined by xmax. Which is not true.

The fact that his speakers and others with low xmax can sound great was never in dispute. It's just that they won't go as loud or as low as a speaker or speakers with the same cone area and a longer xmax. Assuming proper cabinet design which was never in question.

[Roadkill]

Originally Posted by Mike Arnopol

The discussion here about xmax was started by David's claims that SPL in the low end was not necessarily determined by xmax. Which is not true.

Yup, ur right . OTOH (as I think you pointed out also) what folks perceive as "low end" ain't what most folks think it is. I probably enjoy playing through a flat-to-30hz system (possibly with the mids decimated) as much as the next guy but outside of my living room I know that sound ain't gonna cut it. As a sound guy one of my greatest pleasures is "reforming" lifelong "mid cutters" so I can mic their cabs (or at least take a post-EQ DI feed) instead of ignoring their inappropriate "tone" and having to take a pre-EQ DI feed .

[basswave]

I'm playing a Jazz brunch with my the 'Fusion RS210T' this weekend. My 8 year niece is my roadie for that gig...Thank God.

[Mike Arnopol]

Ah the joys of light cabs!

[dukeorock]

Originally Posted by Mike Arnopol

Ah the joys of light cabs!

You aint out frolicking again, are you Mike?

[liam_g]

Originally Posted by basswave

I'm playing a Jazz brunch with my the 'Fusion RS210T' this weekend. My 8 year niece is my roadie for that gig...Thank God.

Cool! I'd love to have a cab my 7 year old daughter could carry for me.

Cheers,
Liam

[dukeorock]

I'm afraid we're gonna have to report all the child labor abuses here

[Mike Arnopol]

Originally Posted by dukeorock

You aint out frolicking again, are you Mike?

Dude---I haven't had any frolic time this year! 4 to 5 gigs a week and working the rest of the time getting cabs out doesn't leave much frolicking time. I used to bitch about being on the road all the time---I really don't miss it but at least I had some down time!

Been through 3 potential assistants---no dice. Oh well----

[dukeorock]

Originally Posted by Mike Arnopol

Dude---I haven't had any frolic time this year! 4 to 5 gigs a week and working the rest of the time getting cabs out doesn't leave much frolicking time. I used to bitch about being on the road all the time---I really don't miss it but at least I had some down time!

Been through 3 potential assistants---no dice. Oh well----

Ouch! I'm sure you'll find the right one soon!

[CL400Peavey]

Originally Posted by Mike Arnopol

Dude---I haven't had any frolic time this year! 4 to 5 gigs a week and working the rest of the time getting cabs out doesn't leave much frolicking time. I used to bitch about being on the road all the time---I really don't miss it but at least I had some down time!

Been through 3 potential assistants---no dice. Oh well----

Now Im kicking myself for moving out of Chi-town a little while ago.

[Mike Arnopol]

I'm still waiting for you to come to Chitown for some hang time!

[Mike Arnopol]

What are the dimensions of the cab?

[kurosawa]

Originally Posted by Roadkill

Yup, ur right . OTOH (as I think you pointed out also) what folks perceive as "low end" ain't what most folks think it is. I probably enjoy playing through a flat-to-30hz system (possibly with the mids decimated) as much as the next guy but outside of my living room I know that sound ain't gonna cut it. As a sound guy one of my greatest pleasures is "reforming" lifelong "mid cutters" so I can mic their cabs (or at least take a post-EQ DI feed) instead of ignoring their inappropriate "tone" and having to take a pre-EQ DI feed .

A friend just gave me a cheap pair of 1 cubic foot 10" PA boxes. They sound like they're about 1/4 or less as loud as the 15PR400 in a MM cab that's sitting right next to them, and oddly, they sound more pleasant. So I'm interested in learning your idea of an ideal bass cab for live performance, both indoors and out. How would it differ from the reigning crop of hi-fi cabs? And if I could drop decent drivers into these boxes--I mean, there is a TON of great 1/2 to 1 cubic foot 10" drivers out there, or better yet, maybe a 310 tower, or 210 plus a downfiring 10--look at these little guys, http://www.usspeaker.com/faital%20pro%2010pr310-1.htm for the existing 1 cu ft boxes, or this 1/2 cubic foot job http://www.usspeaker.com/faital%20pro%2010hp1020-1.htm --that would actually fit in my tiny trunk, man, I'm ready to rock right now!

[pgk]

no, because i'd be chasing it around the stage half the night