Maz
Jan 27 2003, 03:11 AM
After reading that the Alpine Type R has 44mm of mechanical excursion it has got me thinking what the precisions are capable of.
Does anyone know the maximum exursion of a precision 12 or 15?
bassmekanik
Jan 27 2003, 03:26 AM
where did you read that they do 44 i read 55 somwhere
Walkinshaw
Jan 27 2003, 06:00 AM
55mm.......thats a whole bucket of excursion. I didnt think type R's had that much (let alone linear)
BA5513
Jan 27 2003, 07:19 PM
whats the difference between x-max, x-peakand mechanical excursion?
Walkinshaw
Jan 27 2003, 07:49 PM
technicaly X-Max, is the distance the cone can move away from rest(in one direction) with linear travel/control.
X-peak, erm.......i guess the maxamum distance the cone can move in one direction.
Mechanical excursion is the totoal distance the cone can move from peak to peak before reaching extent of surround/spider or pole piece
BA5513
Jan 27 2003, 11:06 PM
So xmax is hpw far the cone can move safley without distortion or harm and mech xcursion is how far it can move when you push it ya self...
Maz
Jan 28 2003, 05:05 PM
Mechanical excursion is how far the sub will travel when your putting 1 kilowatt through the sub during an SPL comp
bassmekanik
Jan 28 2003, 06:47 PM
the correct term is how far it can move peak to peak without leaving the VC gap or whacking the magnet
Bodyjar
Jan 28 2003, 09:09 PM
QUOTE
Originally posted by Maz:
Mechanical excursion is how far the sub will travel when your putting 1 kilowatt through the sub during an SPL comp
Errr... who told you this? That is not correct...
I believe there is a more technical definition, but basically how far the cone can move up and down... one way xmax being how far it can move only one way, and not total...
I dont think the Type Rs have 55mm xmax? thats quite a lot...
the[K]id
Jan 28 2003, 09:34 PM
Ummm, there is 2 parts to xmax, something like xsus and xmag, I dunno, anyway, ask Bassaholic for details, he'll know :-)
One of em is mechanical excursion (how far you can strectch surround/spider, etc) and other is electrical movement (related to things like top plate thickness and VC height). Xmax is the lesser (limiting factor) of the two.
PuRpS
Jan 28 2003, 10:42 PM
i think u would be lucky to get 20mm P TO P out of a jaycar dvc 12
the surround is what holding them back with the fatter surround im sure they would do a lot better
Maz
Jan 28 2003, 11:04 PM
nah 55mm is not its Xmax, that is only 14mm. The specs stay linera up to 14mm but if you put heaps of power through a type R it would move 50mm i take it?
bassmekanik
Jan 28 2003, 11:20 PM
in sealed a type r sould move 50 mm easy i reckon
50mm x-max when I connect it to my 3 phase and the cone launches across the room.
i doubt the cone have 55mm movement one way or both. the spider or surround and basket would hit b4 that.
[ January 28, 2003, 22:03: Message edited by: KraSE ]
BlackIce
Jan 29 2003, 12:35 PM
I do believe mech. X is the furthest the cone can possibly move before inventing a new X by blowing the suspension and launching the cone..
the[K]id
Jan 29 2003, 03:48 PM
QUOTE
Originally posted by bassmekanik:
in sealed a type r sould move 50 mm easy i reckon
If you jump on it?
Free air would give the greater movement, as the Type R has a bit of mech travel I think, prolly just not a heap of elec travel. (Even subs such as inhumans, re's, etc dont do 55mm of anything near linear travel)
Maz
Jan 29 2003, 04:15 PM
nah the Brahma has 27mm of one-way LINEAR excursion. So thats 54mm Peak to Peak, and thats just XMax.
My Venom has an Xmas of 5mm and it moves up to an inch P2P with 450wrms.
So the Brahma would have (guestimate) maximum excursion of well over 60mm Peak to Peak, maybe even 70mm.
So is there 3 excursion specs???
XMax: The amount the cone moves while stayign linear.
X Peak: The maximum the cone can move with power?
Max Mechanical Excursion: Max it can move with your foot standing on it? or Phase 3 power?
[ January 29, 2003, 14:23: Message edited by: Maz ]
the[K]id
Jan 29 2003, 04:26 PM
What, since when have we been talking pk to pk?
Thats like talking peak power, just silly
Walkinshaw
Jan 29 2003, 04:34 PM
Brahma has 27mm one way xmax, yet maximum one way mechanical movement is 28.5mm. Hence the brahma will play clean right up untill it hits mechanical limit. So....DONT PLAY A BRAHMA TILL IT SOUNDS BAD! it means its past its mech limit !
Bassaholic
Jan 29 2003, 06:31 PM
QUOTE
Originally posted by the[K]id:
Ummm, there is 2 parts to xmax, something like xsus and xmag, I dunno, anyway, ask Bassaholic for details, he'll know :-)
One of em is mechanical excursion (how far you can strectch surround/spider, etc) and other is electrical movement (related to things like top plate thickness and VC height). Xmax is the lesser (limiting factor) of the two.
Xsus is the amount of linear suspension travel.. Using wide diameter progressive spiders, and wide foam surrounds, you can get large amounts of linear travel. However, the commonly available suspension components are limited to around 28mm of one way travel..
Xmag is the amount of linear magnetic travel.. However, with the new generation of subwoofer models, the old method of working out xmag by the amount of coil left in the gap is no longer accurate enough.. (particularly with the LGLC - long gap, long coil designs available today)
Xmax is of course the lesser of the two..
bassmekanik
Jan 30 2003, 10:27 PM
i did not mean 50 mm linear travel god i wish that sounds good but not in the next coupla years
Quoted direct from alpine website SWR-1221D
Check the fourth from last line
Thiel Small Parameters
Coil Height (Hvc) : 36.7mm
Cone Area (Sd) : 467.59 sq. cm
D.C.Coil Resistance (Re) : 1.8 ohm + 1.8 ohm
Electrical Q (Qes) : 0.40
Equivalent Suspension Stiffness (Vas) : 58 liters(2.04cu.ft.)
Free Air Resonance (Fs) : 27Hz
Frequency Response : 24Hz - 1kHz
Gap Height (Hag) : 10mm
Impedance (Nominal) : 2 ohm + 2 ohm
Inductance (Le) : 2.41mH at 1kHz (0.84mH at 20kHz)
Linear Excursion (X linear) : 13.35mm
Maximum Excursion (X peak) : 26.7mm
Mechanical Excursion (Peak-to-Peak) : 55mm
Mechanical Q (Qms) : 8.68
Sensitivity : 87 dB/W/M
Total Loudspeaker Q (Qts) : 0.38
[ January 30, 2003, 20:29: Message edited by: bassmekanik ]
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