XXX vs. MX

[SQBubble 10+ year member]

last time i remember the LMT ( all tc sounds driver) had the most linear curve, between xbl^2 and all the other drivers... but are ineficient though...

is that correct?

also, yall should consider the new lms in this discussion... i'm curious about it..

 

[audioholic 5,000+ posts]

last time i remember the LMT ( all tc sounds driver) had the most linear curve, between xbl^2 and all the other drivers... but are ineficient though...
is that correct?

also, yall should consider the new lms in this discussion... i'm curious about it..

Im not sure Ive seen a BL curve on the LMT, but I assume its flat. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif If its flatter than an xbl^2 topology, it cant be by much as xbl^2 has an extremely flat BL curve already (same/very similar to other BL optimized motor designs like the split coil, the W7's motor, etc).

I have zero experience with the LMT so I'll leave my comments at that.

 

[newusername 10+ year member]

Im not sure Ive seen a BL curve on the LMT, but I assume its flat. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif If its flatter than an xbl^2 topology, it cant be by much as xbl^2 has an extremely flat BL curve already (same/very similar to other BL optimized motor designs like the split coil, the W7's motor, etc).
I have zero experience with the LMT so I'll leave my comments at that.

Most LMT drivers are pretty much ruler flat until the whole voice coil leaves the gap, which is a lot of linear travel because they are also pretty tall voice coils. It is easily the most linear technology out there. It has it's own positives and negatives to it. It is not a particularly efficient option unless you add a lot of B (Mms is very high due to the large number of windings), but Fs is very low due to the high Mms. Inductance isn't very good (again, a function of the voice coil), but BL linearity is exceptional.

I know I don't have to say this to you as an engineer, but there's always sacrifices.

 

[95stroked1500 10+ year member]

i was commenting back in one post to multiple trains of thoughts. so it might not pertain to just one poster.

i never said the spider was the only factor. it is a very important factor that not just everyone can master to the degree that others can. i have never discredited the importance of the coil and gap geometries, the cone material, etc, each having an effect on the big picture.

it was asked what to tweek where. i cannot go over that info. what i learned, was under the word that i wouldn't openly pass certain things along. sorry, i will not.

all i can say is observe spider movement. see how and where it flexes under diff power levels and different tunes. apply the coating to certain regions, and note the changes in sound. is one method of finite tuning. it can be done to an assembled speaker. it is very time consuming. there is also the major changes of dropping in new soft parts with different base parameters to the suspension.

yes, modeling programs are useful to get you close.

we can do a lot more today with calculating and predicting than we could 10 years ago. but we still are not 100% on track where we need to be. and that is my biggest arguement.

the day we produce 100% dynamic results to what was modeled, when just any ol' company can produce a high end speaker because the science is dialed, speakers that are 90% efficient instead of .3% - 2%, i will have more positive attitude on using pure science and physics on acoustical reproduction.

i'm not trying to attack or bash anyone. so don't take it as such. i'm just standing on a different side of the fence.

 

[audioholic 5,000+ posts]

i was commenting back in one post to multiple trains of thoughts. so it might not pertain to just one poster.
i never said the spider was the only factor. it is a very important factor that not just everyone can master to the degree that others can. i have never discredited the importance of the coil and gap geometries, the cone material, etc, each having an effect on the big picture.

it was asked what to tweek where. i cannot go over that info. what i learned, was under the word that i wouldn't openly pass certain things along. sorry, i will not.

all i can say is observe spider movement. see how and where it flexes under diff power levels and different tunes. apply the coating to certain regions, and note the changes in sound. is one method of finite tuning. it can be done to an assembled speaker. it is very time consuming. there is also the major changes of dropping in new soft parts with different base parameters to the suspension.

yes, modeling programs are useful to get you close.

we can do a lot more today with calculating and predicting than we could 10 years ago. but we still are not 100% on track where we need to be. and that is my biggest arguement.

the day we produce 100% dynamic results to what was modeled, when just any ol' company can produce a high end speaker because the science is dialed, speakers that are 90% efficient instead of .3% - 2%, i will have more positive attitude on using pure science and physics on acoustical reproduction.

i'm not trying to attack or bash anyone. so don't take it as such. i'm just standing on a different side of the fence.

Thankyou for the explanation 95stroked.

I guess what Im missing at this point is, are you saying this process is not accounted for with American made subwoofers? If this subtle nuance to speaker design is so necessary as to render specialists in training for years, and American companies cant get it right, why do we have so many companies that build such musical subwoofers? I wont get into any US vs European arguements, but it seems anyone arguing American manufacturers cant make a top notch SQ sub are simply biased, and wrong. No offense to your friend, everyone has a bias. Too bad his wasn't made more positive, but sadly I understand... we Americans can be such d*cks. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

Again, Im no subwoofer designer, but it seems to me a technological advance like BL optimization (American invention) would make a more audible difference, across a wider spectrum of install possibilities, than would subtle changes to the spider coatings. But then, as stated in this thread (by myself and others), a table-top BL curve isn't always preferred. *shrug* My point is everything has its place.

Im confident your European friend would think one of his hand built subs sounds superior to a driver who factually outputs less distortion, at any/all levels... but then the arguement over whether SQ is subjective or not comes up. Who cares. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Im sure your friend will make a comfortable living tweaking spiders, and American companies will continue improving their designs as well, and the vast majority of car audio 'enthusiasts' will still go out and buy whatever their cousin tells them "bumps the hardest".

Im not sure I completely agree, but again I do thank you for explaining your position better.

 

[I want SExxx 10+ year member]

1. For someone who behaves as if you have a great grasp on motor topologies, why would you make such a bad blanket statement? "split coil = better then XBL^2 for More power and getting louder." Sure, that's true if there's more coil than on the XBL^2 motor that's being compared. It certainly doesn't make for a great blanket statement. Look at the other positives that make XBL^2 a much better topology than split coil.
2. SQ is not subjective; sonic preference is. A speaker that accurately reproduces the input signal is an "SQ" speaker (god I hate that term) and no audible interpretation can change that. A speaker that sounds good but fails to produce the input signal accurately is NOT an "SQ" speaker.

1. Split coil used in an application to get the same results as XBL^2, will have a larger coil. That's the nature of the design. XBL^2 uses smaller coils. And XBL^2 is not better then split coil. If it were then why would Scott Atwell use split coil after using XBL^2. I know XBL^2 has it's advantages, but I'm not a fan. I believe that you do not have to use a linear motor to have a great sounding driver, the Arsenal for example (IN MY OPINION) is a much better sounding driver the a brahma or XXX. I guess my biggest beef in an XBL^2 design is it is extremely inefficient. Your cutting the motor strength in half so you have to use huge motors that act like tiny motors once everything is said and done. Take the arsenal and Avalanche for example. In a ported enclosure they have almost identical output levels, in fact the arsenal is a tad bit louder. And that is a fine example of a driver getting plenty loud and sounding just as good using traditional motor designs.

2. SQ is subjective. Driver A may accurately produce 20-40hz but have serious lag in the upper frequencies. While driver B will be great at reproducing higher pitches and quick basslines. The driver C comes in and plays every note flawlessly, but has to have serious eqing to make up for lost low end. There is not one single subwoofer out there that can do it all perfectly from 10 hz to 80 hz rumbles to punches and fast basslines to slower basslines. That is why SQ is subjective. Now can you say that an Avalanche sounds better then an MT? Yes by all means that can be said, because it does in almost every aspect, unless you like mechanical sounds.

 

[audioholic 5,000+ posts]

Sound Quality is not subjective. Is water quality subjective? How about air quality? These are measureable quantities. The accuracy of the reproduction of the original recording, that is sound quality. But, our means for measuring it many times IS subjective. Add to that the notion everyone should be able to individually determine what 'sound quality' is based on their own personal preferences, and you have yourself one miscontrued term.

Again, I personally prefer the sound of my IDQ's to my XXX's. But I wont try and fool myself into believing the IDQ's are technically more accurate. That's exactly what some of you guys are attempting to do here.

Lets not start comparing 'output levels' of various types motors, many times that's a function of the particular design, enclosure size/type/alignment etc... not necessarily the motor topology.

 

[zebo 10+ year member]

1. Split coil used in an application to get the same results as XBL^2, will have a larger coil. That's the nature of the design. XBL^2 uses smaller coils. And XBL^2 is not better then split coil. If it were then why would Scott Atwell use split coil after using XBL^2. I know XBL^2 has it's advantages, but I'm not a fan. I believe that you do not have to use a linear motor to have a great sounding driver, the Arsenal for example (IN MY OPINION) is a much better sounding driver the a brahma or XXX. I guess my biggest beef in an XBL^2 design is it is extremely inefficient. Your cutting the motor strength in half so you have to use huge motors that act like tiny motors once everything is said and done. Take the arsenal and Avalanche for example. In a ported enclosure they have almost identical output levels, in fact the arsenal is a tad bit louder. And that is a fine example of a driver getting plenty loud and sounding just as good using traditional motor designs.
2. SQ is subjective. Driver A may accurately produce 20-40hz but have serious lag in the upper frequencies. While driver B will be great at reproducing higher pitches and quick basslines. The driver C comes in and plays every note flawlessly, but has to have serious eqing to make up for lost low end. There is not one single subwoofer out there that can do it all perfectly from 10 hz to 80 hz rumbles to punches and fast basslines to slower basslines. That is why SQ is subjective. Now can you say that an Avalanche sounds better then an MT? Yes by all means that can be said, because it does in almost every aspect, unless you like mechanical sounds.

What you need to stop and realize\accept is that the function of a speaker is to as accurately as possible reproduce its input signal. That means the driver with the least amount of distortion will be closest to the intended goal. That said, just accept the fact that you prefer drivers that introduce some distortion to the original signal. Period. If you are going to try and tell me that a standard motor is going to sound better to you than a linear one, great , that’s your preference but the truth of the matter is that you are preferring some added distortion. Is this an insult to you , your ability to perceive distortion ect.. hell no, but you could at least accept it for what it is.

I don’t know why people can’t realize that just because a driver may be preferable to your ear, it certainly does not mean it is because it is the most accurate.

…and if you don’t mind, validate your statement about xbl being inefficient and requiring a huge motor. I personally think you are blowing smoke about that whole topic.

 

[newusername 10+ year member]

…and if you don’t mind, validate your statement about xbl being inefficient and requiring a huge motor. I personally think you are blowing smoke about that whole topic.

No, he's totally correct about that statement.

Efficiency = (B^2 * L^2) / (R * Sd^2 * Mms^2)

XBL^2 machines a notch in the gap. This notch decreases B in an effort to flatten the overall BL curve. As well, it uses a smaller coil similar to an underhung motor. Due to the nature of the efficiency equation, lower B and lower L causes a pretty big drop in efficiency. Yes, the BL is very linear, but there is certainly a BL sacrifice made and that hurts efficiency.

 

[zebo 10+ year member]

No, he's totally correct about that statement.
Efficiency = (B^2 * L^2) / (R * Sd^2 * Mms^2)

XBL^2 machines a notch in the gap. This notch decreases B in an effort to flatten the overall BL curve. As well, it uses a smaller coil similar to an underhung motor. Due to the nature of the efficiency equation, lower B and lower L causes a pretty big drop in efficiency. Yes, the BL is very linear, but there is certainly a BL sacrifice made and that hurts efficiency.

Oh I understand, but he is making it sound like that the efficiency issue is a complete show stopper, there are plenty of excellent drivers that use xbl that don't require tons of power, same goes for any other topology.

What I was getting at is that he sounds like he just doesn't like it for whatever (non technical) reason.

IMO the slight drop in efficiency and lower thermal power handling are acceptable tradeoffs for the end result.

 

[B_Campbell 10+ year member]

Sound Quality is not subjective. Is water quality subjective? How about air quality?

I think NIKE shoes quality is crap, others don't. I think thats the notion he was getting, what sounds good to some might not for others, not that accuracy is subjective.

 

[Brian Owens 10+ year member]

Man I guess I am in trouble. . . .MT's sound awesome to me. Play 80's music like no other.

Oh, BTW, I added this reply to get rid of "Hello Brian Owens it appears that you have not posted on our forums in several weeks, why not take a few moments to ask a question, help provide a solution or just engage in a conversation with another member in any one of our forums?" at the top of my screen, but I REALLY do like the sound of my MT's //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Brian

 

[B_Campbell 10+ year member]

Man I guess I am in trouble. . . .MT's sound awesome to me. Play 80's music like no other.

Oh, BTW, I added this reply to get rid of "Hello Brian Owens it appears that you have not posted on our forums in several weeks, why not take a few moments to ask a question, help provide a solution or just engage in a conversation with another member in any one of our forums?" at the top of my screen, but I REALLY do like the sound of my MT's //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Brian

Are you going to rice killers next week?

 

[SQBubble 10+ year member]

Man I guess I am in trouble. . . .MT's sound awesome to me. Play 80's music like no other.

Oh, BTW, I added this reply to get rid of "Hello Brian Owens it appears that you have not posted on our forums in several weeks, why not take a few moments to ask a question, help provide a solution or just engage in a conversation with another member in any one of our forums?" at the top of my screen, but I REALLY do like the sound of my MT's //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Brian

wow man, by lookin' at your sig, I have to ask... for how long you've been in car audio and is 140-145db loud for you or not?

 

[tommyk90 5,000+ posts]

And this thread, my friends, is a shining example of why I stick to SPL competitions.

I have the objectivity of an SPL meter that is consistent across the board instead of having 1 person tell me that another driver "sounds better" than the other because of either 1) their personal opinion or 2) because some T/S spec sheet and a computer program told them so.

Please try to tell me that you can guarantee higher SPL performance based off a T/S sheet, then I'll laugh at you and show you my test results with numerous "SPL-oriented" woofers.