Sundown vs Type-R help chew chew chewsing

[audioholic 5,000+ posts]

jacob says a sub with a flat bl curve will have lower distortion and be more true to the music over an overhung motor like sundowns.
thats not proving the alpine type r will be better, but generally with the designs the subs use, the alpine should have less distortion, and be the more accurate driver.

To understand this topic, you need to understand BL, and how it affects performance. BL is, of course, motor forced applied to the coil via the magnetic field. Motor force isn't, as most people think, simply the force to 'push' the cone in or out, its the force to control cone motion. The motor force doesn't simply throw the cone out, then let it bounce off the suspension and rebound back to center. It extends the cone in one direction (imagine hooking a speaker to DC), then the signal reverses polarity which slows and stops the cone's motion (aided by the suspension), and reverses it, to start the cycle over again.

Now that you understand how BL controls cone motio

Standard overhung and underhung motor topologies lose motor force at a fairly steady rate. The further the coil moves from the center position (the further the cone excursion is), the less of the coil is in the area of the concentration of effective magnet flux.

Now that you understand how BL controls cone motion, that standard motor designs with parabolic shaped BL curves lose motor force as cone excursion increases, and that at maximum cone excursion is simultaneously when the speaker needs all the motor force it can to reverse cone motion AND is also the same time motor force is the least, you can understand why "BL distortion" is responsible for about 80% of speaker induced distortion.

XBL^2 motors have a pretty much flat BL 'curve'. Their BL tends to be very linear, with much steeper drop offs in BL at each end when compared to the gentler slopes of the standard designs. XBL^2 setups (and BL optimized motors in general) are designed to work within this plateau of flat BL, keeping their motor force very consistent throughout the cone's stroke. In other words, the motor is basically just as strong at full cone excursion as it is when the coil is centered. BL distortion, which again accounts for about 80% of audible distortion from a speaker, is lowered to inaudible levels.

Now with all that being said, a couple other factors must be remembered. When I talk about BL distortion accounting for '80% of speaker distortion', that's only talking about the distortion generated by the speaker itself. That is speaker-level distortion. There is also signal-level distortion, which is distortion generated in the signal chain and passed on to the amplifier to process just like the original signal material. In other words, removing the vast majority of speaker-level distortion doesn't mean your system will never sound distorted again, the sub can/would still make audible any distortion coming from over-driving the signal source (h/u) or amplifier.

Another factor to consider is, not everyone prefers the 'sound' a BL optimized driver creates. Think about it, the vast majority of music we have ever listened to in our lives, was not live, it's been reproduced, by speakers, virtually of which have had a parabolic BL curve. Many of us are so use to hearing our favorite music WITH that BL distortion, that it feels natural, and when its gone something is wrong. Psychoacoustics at work.

The last contributing factor is, distortion levels are not the only factor in determining the 'audible footprint' a speaker creates. Suspension type/stiffness, fs and other design specs, and of course the enclosure design itself (and how it interacts with the speaker placed in it) all contribute to how a speaker 'sounds' to a person. Dont obsess over BL curves or distortion levels if it means ignoring other contributing factors.

 

[09civic 5,000+ posts]

To understand this topic, you need to understand BL, and how it affects performance. BL is, of course, motor forced applied to the coil via the magnetic field. Motor force isn't, as most people think, simply the force to 'push' the cone in or out, its the force to control cone motion. The motor force doesn't simply throw the cone out, then let it bounce off the suspension and rebound back to center. It extends the cone in one direction (imagine hooking a speaker to DC), then the signal reverses polarity which slows and stops the cone's motion (aided by the suspension), and reverses it, to start the cycle over again.
Now that you understand how BL controls cone motio

Standard overhung and underhung motor topologies lose motor force at a fairly steady rate. The further the coil moves from the center position (the further the cone excursion is), the less of the coil is in the area of the concentration of effective magnet flux.

Now that you understand how BL controls cone motion, that standard motor designs with parabolic shaped BL curves lose motor force as cone excursion increases, and that at maximum cone excursion is simultaneously when the speaker needs all the motor force it can to reverse cone motion AND is also the same time motor force is the least, you can understand why "BL distortion" is responsible for about 80% of speaker induced distortion.

XBL^2 motors have a pretty much flat BL 'curve'. Their BL tends to be very linear, with much steeper drop offs in BL at each end when compared to the gentler slopes of the standard designs. XBL^2 setups (and BL optimized motors in general) are designed to work within this plateau of flat BL, keeping their motor force very consistent throughout the cone's stroke. In other words, the motor is basically just as strong at full cone excursion as it is when the coil is centered. BL distortion, which again accounts for about 80% of audible distortion from a speaker, is lowered to inaudible levels.

Now with all that being said, a couple other factors must be remembered. When I talk about BL distortion accounting for '80% of speaker distortion', that's only talking about the distortion generated by the speaker itself. That is speaker-level distortion. There is also signal-level distortion, which is distortion generated in the signal chain and passed on to the amplifier to process just like the original signal material. In other words, removing the vast majority of speaker-level distortion doesn't mean your system will never sound distorted again, the sub can/would still make audible any distortion coming from over-driving the signal source (h/u) or amplifier.

Another factor to consider is, not everyone prefers the 'sound' a BL optimized driver creates. Think about it, the vast majority of music we have ever listened to in our lives, was not live, it's been reproduced, by speakers, virtually of which have had a parabolic BL curve. Many of us are so use to hearing our favorite music WITH that BL distortion, that it feels natural, and when its gone something is wrong. Psychoacoustics at work.

The last contributing factor is, distortion levels are not the only factor in determining the 'audible footprint' a speaker creates. Suspension type/stiffness, fs and other design specs, and of course the enclosure design itself (and how it interacts with the speaker placed in it) all contribute to how a speaker 'sounds' to a person. Dont obsess over BL curves or distortion levels if it means ignoring other contributing factors.

Holy story

 

[ejschultz 10+ year member]

I feel enlightened after reading that. I now understand BL a little bit better. Thanks.

 

[dragonrage 10+ year member]

Holy story

There's a quiz on Friday, so make sure to study up.

 

[09civic 5,000+ posts]

I feel enlightened after reading that. I now understand BL a little bit better. Thanks.

How could you not when its that long lol

 

[Cruzer 10+ year member]

Now that you understand how BL controls cone motion, that standard motor designs with parabolic shaped BL curves lose motor force as cone excursion increases, and that at maximum cone excursion is simultaneously when the speaker needs all the motor force it can to reverse cone motion AND is also the same time motor force is the least, you can understand why "BL distortion" is responsible for about 80% of speaker induced distortion.
XBL^2 motors have a pretty much flat BL 'curve'. Their BL tends to be very linear, with much steeper drop offs in BL at each end when compared to the gentler slopes of the standard designs. XBL^2 setups (and BL optimized motors in general) are designed to work within this plateau of flat BL, keeping their motor force very consistent throughout the cone's stroke. In other words, the motor is basically just as strong at full cone excursion as it is when the coil is centered. BL distortion, which again accounts for about 80% of audible distortion from a speaker, is lowered to inaudible levels.

Now with all that being said, a couple other factors must be remembered. When I talk about BL distortion accounting for '80% of speaker distortion', that's only talking about the distortion generated by the speaker itself. That is speaker-level distortion. There is also signal-level distortion, which is distortion generated in the signal chain and passed on to the amplifier to process just like the original signal material. In other words, removing the vast majority of speaker-level distortion doesn't mean your system will never sound distorted again, the sub can/would still make audible any distortion coming from over-driving the signal source (h/u) or amplifier.

Another factor to consider is, not everyone prefers the 'sound' a BL optimized driver creates. Think about it, the vast majority of music we have ever listened to in our lives, was not live, it's been reproduced, by speakers, virtually of which have had a parabolic BL curve. Many of us are so use to hearing our favorite music WITH that BL distortion, that it feels natural, and when its gone something is wrong. Psychoacoustics at work.

The last contributing factor is, distortion levels are not the only factor in determining the 'audible footprint' a speaker creates. Suspension type/stiffness, fs and other design specs, and of course the enclosure design itself (and how it interacts with the speaker placed in it) all contribute to how a speaker 'sounds' to a person. Dont obsess over BL curves or distortion levels if it means ignoring other contributing factors.

i have much to learn, i know this, and i dont claim to know everything.

u bring up signal-level distortion, but thats not what were discussing here. even if u do have significant signal-level distortion, replacing a high distortion driver with a lower distortion driver, u should still notice a difference in the lower distortion. u will still have a lot because its signal related, but it should still be reduced from driver to driver. no?

99.9% of people believe **** is ok, does that mean its ok? or over 50% of the world smokes, does that make it ok? just because most people feel a low distortion driver, low bl curve driver doesnt sound right, doesnt mean it doesnt. ive seen lots of people talk about xbl2 subs sounding dry and lifeless, and after i talk with them, i get them to admit that they like distortion, which is why they dont like the "dry" and "lifeless" sound of the low distortion xbl2 subs.

i, and jacob(in the post i linked) both said generally speaking a driver with a flat bl curve generally sounds better than one that is not so flat. there are more than just flat bl curve to distortion and sq, but its a great start. if u ask me, a flat bl curve should be at least minimial to all drivers.

big thing that jacob points out in the post that i linked, is that they have to use overhung with people like on this forum, that want to put x2, x3 the rated power, and push subs to their limits. overhung is more durable, and allows for the other parts to be more durable for the high power.

imo thats why so many people know nothing, or little of bl curves, or sq, or distortion. they havent heard low distortion, so they dont care, and dont care to learn/read about it.

good info you provided though, always good to read more

 

[outsideshot23 10+ year member]

i dont like to jump on the sundown boner but if those are the options.. lol.

 

[Ge_off_me 5,000+ posts]

Go get 2 12'' Incriminator Audio Lethal Injections //content.invisioncic.com/y282845/emoticons/thumbsup.gif.3287b36ca96645a13a43aff531f37f02.gif

 

[dragonrage 10+ year member]

i, and jacob(in the post i linked) both said generally speaking a driver with a flat bl curve generally sounds better than one that is not so flat. there are more than just flat bl curve to distortion and sq, but its a great start. if u ask me, a flat bl curve should be at least minimial to all drivers.

A non-flat BL curve will ALWAYS ALWAYS ALWAYS cause distortion when played past the point of BL linearity. It's always going to be best to have a way to linearize the BL curve such as underhung topology, or XBL^2 or LMS.

This is why some people do Klippel testing of subwoofers. I would go so far as to say that ANY driver that doesn't have a nice BL curve is useless garbage. Since this is not the only factor in a good speaker, there are also drivers that do have a nice BL curve that also ****.

 

[Liquid Bass 10+ year member]

Type Rs are loud and can take a lot of power. My vote goes to the R for spl. Plus the price is better

 

[Guyver 10+ year member]

EZ, consider other subs.... go with volfenhag or pyramid. They never disappoint.

 

[dragonrage 10+ year member]

Type Rs are loud and can take a lot of power. My vote goes to the R for spl. Plus the price is better

The SA12 has a little bit more Xmax then the Type R, but it's VERY close. The R does lose, though. I wouldn't consider either of them for any sound quality applications. For SPL, SA12 can move just a bit more air.

Type R is never the answer for anyone who cares about their system. Ever. Type R's are for recommending to people that ask us about subwoofers when we don't want to spend the effort explaining where to get the real good stuff.

 

[Cruzer 10+ year member]

A non-flat BL curve will ALWAYS ALWAYS ALWAYS cause distortion when played past the point of BL linearity. It's always going to be best to have a way to linearize the BL curve such as underhung topology, or XBL^2 or LMS.
This is why some people do Klippel testing of subwoofers. I would go so far as to say that ANY driver that doesn't have a nice BL curve is useless garbage. Since this is not the only factor in a good speaker, there are also drivers that do have a nice BL curve that also ****.

i agree, but try and explain that to 99.9% of people around here. i wouldnt go as far and call them useless garbage, but, ya i love when something like the FI Q gets called a sq subwoofer when its not going to sound any better than all the other subs mentioned on here. though i did read somewhere recently that the "I Heat Ring" option is a shorting ring. then would the FI Q be better than some, but still not going to be a highly regarded sq sub

 

[audioholic 5,000+ posts]

i have much to learn, i know this, and i dont claim to know everything.
u bring up signal-level distortion, but thats not what were discussing here. even if u do have significant signal-level distortion, replacing a high distortion driver with a lower distortion driver, u should still notice a difference in the lower distortion. u will still have a lot because its signal related, but it should still be reduced from driver to driver. no?

99.9% of people believe **** is ok, does that mean its ok? or over 50% of the world smokes, does that make it ok? just because most people feel a low distortion driver, low bl curve driver doesnt sound right, doesnt mean it doesnt. ive seen lots of people talk about xbl2 subs sounding dry and lifeless, and after i talk with them, i get them to admit that they like distortion, which is why they dont like the "dry" and "lifeless" sound of the low distortion xbl2 subs.

i, and jacob(in the post i linked) both said generally speaking a driver with a flat bl curve generally sounds better than one that is not so flat. there are more than just flat bl curve to distortion and sq, but its a great start. if u ask me, a flat bl curve should be at least minimial to all drivers.

big thing that jacob points out in the post that i linked, is that they have to use overhung with people like on this forum, that want to put x2, x3 the rated power, and push subs to their limits. overhung is more durable, and allows for the other parts to be more durable for the high power.

imo thats why so many people know nothing, or little of bl curves, or sq, or distortion. they havent heard low distortion, so they dont care, and dont care to learn/read about it.

good info you provided though, always good to read more

You are correct that we are not discussing signal level distortion here. That was my point, that people here not confuse signal distortion with speaker-level distortion.

Yes, less BL distortion, even in a system with significant signal distortion, will result in less over all inaccuracy. I never intended to imply one trumped the other.

Just because so many people prefer BL distortion in their speaker does not make it right, no. My point was just because one speaker looks better on paper, or in this case on a computer screen, doesn't mean someone should run out and buy it. Accuracy is objective, listener preference is subjective.

You are exactly correct on the wide spread use (still) of the over hung design in the marketplace.

 

[Cruzer 10+ year member]

Just because so many people prefer BL distortion in their speaker does not make it right, no. My point was just because one speaker looks better on paper, or in this case on a computer screen, doesn't mean someone should run out and buy it. Accuracy is objective, listener preference is subjective.
You are exactly correct on the wide spread use (still) of the over hung design in the marketplace.

They dont have to run out and buy it, but if ur looking to upgrade the SQ in ur setup, or when buying new imo u should look for something that will produce the music most accurate, which would be a low distortion driver over something that changes the sound with distortion.