Exmax

[Nate197]

I do not understand EXmax fully because the specifications for my sub say that it can handle 16.1 mm. I thought EXmax meant how much excursion the sub could handle. I think my sub is getting about an inch of excursion. What do they mean when they say 16.1 mm thanks.

[chewie]

xmax is peak to peak measurement. max + and max - movement. so your speaker moves 16.1 mm from the maximum- to the maximum + without damage

so safely your speaker moves 0.6 of an inch just above half an inch

please do correct me if im wrong. this is my understanding

Edited May 11, 2008 by cerwinvega

[LSN2meBoom916]

xmax is peak to peak measurement. max + and max - movement. so your speaker moves 16.1 mm from the maximum- to the maximum + without damage

so safely your speaker moves 0.6 of an inch just above half an inch

please do correct me if im wrong. this is my understanding

You're partially right.

Although this term is used "loosely" among many companys it's a lot like "real wattage" ratings.

Everyone is gonna give the figure that makes them look the best.

Some companies (the good ones) give their xmax rating in terms of "One way, linear" meaning the most USABLE excursion you can get out of a given sub before it starts moving NON-linearly (sideways or askew/at angle).

Non linear or NOT straight in and out means the cone is moving in a way that will possibly permit its Voice coil to contact the inside of the magnet and short out or burn the coil (I'm sure there's a name for this area around where the voice coil resides... I wanna say shorting ring or maybe considered part of the gap? I'll have to look it up and edit this later).

If the sub moves NON linearly (sideways or askew) enough to make contact with that part while the Voice coil is energized...=all bad. Blown sub.

So yes it's how much the sub will move, and yes some companies give thier "peak to peak" measurement and others give it as "one way linear" (which means it's really twice the number they give..if ur accounting for positive+ stroke and negative- stroke)

EDIT*

I looked around and I guess I was right the 1st time

The area in which the voice coil resides is referred to as "the air gap"..on more than one site I was reading...including:

http://www.cyberus.ca/~ec091357/TheVoiceCoilAndMagnet.shtml

Some good info here too

http://www.angelfire.com/ultra2/london/

Edited May 11, 2008 by LSN2meBoom916

[chewie]

You're partially right.

Although this term is used "loosely" among many companys it's a lot like "real wattage" ratings.

Everyone is gonna give the figure that makes them look the best.

Some companies (the good ones) give their xmax rating in terms of "One way, linear" meaning the most USABLE excursion you can get out of a given sub before it starts moving NON-linearly (sideways or askew/at angle).

Non linear or NOT straight in and out means the cone is moving in a way that will possibly permit its Voice coil to contact the inside of the magnet and short out or burn the coil (I'm sure there's a name for this area around where the voice coil resides... I wanna say shorting ring or maybe considered part of the gap? I'll have to look it up and edit this later).

If the sub moves NON linearly (sideways or askew) enough to make contact with that part while the Voice coil is energized...=all bad. Blown sub.

So yes it's how much the sub will move, and yes some companies give thier "peak to peak" measurement and others give it as "one way linear" (which means it's really twice the number they give..if ur accounting for positive+ stroke and negative- stroke)

thanks for clearing that up.

ive already learned so much just by browsing these forums.

[LSN2meBoom916]

thanks for clearing that up.

ive already learned so much just by browsing these forums.

Np.

Welcome to the good forum. (smd)

Also just an aside...

"Xmax is defined as the width of the voice coil that extends beyond the front plate plus 15% (See Diagram 2). This relates to how far the speaker can move in either direction without appreciable distortion."

From:

http://www.xtant.com/archives/html/techSupport/speakers.cfm

Edited May 11, 2008 by LSN2meBoom916

[chewie]

Np.

Welcome to the good forum. (smd)

Also just an aside...

"Xmax is defined as the width of the voice coil that extends beyond the front plate plus 15% (See Diagram 2). This relates to how far the speaker can move in either direction without appreciable distortion."

From:

http://www.xtant.com/archives/html/techSupport/speakers.cfm

so is this why i can see about a inch and a half of voice coil sticking above the face of the motor on my brothers c.v vmax 15?

his speaker also has dual spiders. i hear this improves sq at high excursion rates it keeps the voice coil nice and straight in the motor and keeps the voice coil from hitting the magnet. the spiders are offset so at + stroke the bottom one is straight and at - stroke the top on is straight this is at the +- stroke extremes.

Edited May 11, 2008 by cerwinvega

[LSN2meBoom916]

so is this why i can see about a inch and a half of voice coil sticking above the face of the motor on my brothers c.v vmax 15?

his speaker also has dual spiders. i hear this improves sq at high excursion rates it keeps the voice coil nice and straight in the motor and keeps the voice coil from hitting the magnet. the spiders are offset so at + stroke the bottom one is straight and at - stroke the top on is straight this is at the +- stroke extremes.

Hmmmm....

You can see the voice coil?...are you missing a dustcap perhaps?

Is it the older Vmax w/ the red surrounds and pulp (i think) cone? or the newer ones w/ the aluminum cone?

I don't see in EITHER case how you could see the VC sticking up...? and..."above the face of the motor"....huh? You shouldn't be able to see that either....the face of the motor should be hidden by the spider/s, which would be covered by the cone which attaches to it at the center, and then that is topped off w/ the dust cap if there is one...

So hmmmm....you got me buddy.

Pix?

Edited May 11, 2008 by LSN2meBoom916

[chewie]

Hmmmm....

You can see the voice coil?...are you missing a dustcap perhaps?

Is it the older Vmax w/ the red surrounds and pulp (i think) cone? or the newer ones w/ the aluminum cone?

I don't see in EITHER case how you could see the VC sticking up...? and..."above the face of the motor"....huh? You shouldn't be able to see that either....the face of the motor should be hidden by the spider/s, which would be covered by the cone which attaches to it at the center, and then that is topped off w/ the dust cap if there is one...

So hmmmm....you got me buddy.

Pix?

you can see it if you look through the side. there is quite a gap for air flow to cool the coil below the spiders. the spiders are up high. but its definatly visable. when i have the speaker in hand ill snap some pics.

hes pushed it preety hard and after a hard run theres no real heat buildup near the center of the cone. even when he reverse mounted one. (we were messin around) the motor and everything wasnt any warmer than luke warm. this is pushing the speaker with around 900 watts rms

edit*

http://cas07.businessflow.ms/3.9.5/media/g...73ad&size=1

theres a pic of a 15.... the three slots are all the way around the speaker and you can get quite a view of the voice coil from there.

its a new one but they are still pulp cones. theres a very very thin aluminum/plastic..decal/dustcap that covers the whole cone. the whole cone is very light . i got to hold a voice coil/cone when my brothers failed due to a car accident. blew outta the box and something hit the center .

for what we paid for these speakers 99 apeice otd i was really impressed with the quality and the sound.

17.4 mm of xmax it isnt much but thats what you get with most low end speakers.

the stroker pro has triple spiders and adjustable xmax. up too 44.5 mm

Edited May 11, 2008 by cerwinvega

[LSN2meBoom916]

Hmmm...ok.

well unless I'm just totally misunderstanding what exactly ur asking...you wanna know why you can SEE the VC through those vent holes?

If THAT's the Q then the answer is easy...its simply because the designer chose to put holes there so air could flow in and out as the speaker moved and that would provide air cooling for the VC.

If there's some other Q here i guess just try askin it again, and I'll try to answer/better, it if I can, if I havn't already...you tell me.

I think we're on diff pages for some reason.

Edited May 11, 2008 by LSN2meBoom916

[chewie]

Np.

Welcome to the good forum. (smd)

Also just an aside...

"Xmax is defined as the width of the voice coil that extends beyond the front plate plus 15% (See Diagram 2). This relates to how far the speaker can move in either direction without appreciable distortion."

From:

http://www.xtant.com/archives/html/techSupport/speakers.cfm

nope i was just verifying what you posted