Yes.
Hmm. the 18" has not more linear x but xmax is P-P 40mm. With 96.5dB/W.
table with Thile Small of all TADs
http://www.pioneerelectronics.com/Pioneer/CDA/Industrial/SpecificationDetails/0,1448,1541,00.html
zx3chris said:http://www.stryke.com/store/shop.cgi/page=preorder.html/SID=PUT_SID_HERE
stryke AV15
xmax 23mm one way
Fs: 19.7 Hz
Qms: 4.71
Qes: .399
Qts: .368
Vas: 228 L
Re: 2.97 ohm
Z: 4 ohm
BL: 15.5 Tm
Cms: .25 mm/N
Mms: 260 g
Pe: 500W
1W/1m: 88.5dB
2.83V: 92.5dB
Xmax: 23 mm
Xsus: 30 mm
Sd: 802 sq cm
Vd: 3.8 L
these are amazing subs...
bottomline, if you want volume you need to move the air. this means you need area, and you need excursion.
when looking at subs, checking their eff is prolly the least important parameter. most often it is not accurate at all and it changed anyway by the installation or enclosure it is put into. as far as making subs 8ohms??? why.. the lower impedence the better, get more power out of your amps---and i hope no one talks about damping
I have this woofer in my files. Can I ask you a question?
When they say Xmax 23mm, and Xsus 30 mm, do
they mean Xmech? And if so, How can the Xmax
be 7 mm to the Xsus?
While I'll agree moving air is good, without,
power, and, efficiency (no. 0.421%) aren't
we back at stage one?
Can anyone explain why efficiency is not a factor.
Here we have the AV 15, and the 6174. The
AV 15 is 4 ohms, and the 6174 is 8 ohms.
Both are getting 500 watts. Both are
scaled under "High Fidelity" recomendation.
Since, I'm not talking box size here, why should
I take the AV 15, over the 6174?
Here we have the AV 15, and the 6174. The
AV 15 is 4 ohms, and the 6174 is 8 ohms.
Both are getting 500 watts. Both are
scaled under "High Fidelity" recomendation.
Since, I'm not talking box size here, why should
I take the AV 15, over the 6174?
Attachments
It doesn't matter, the rules are the same. A PA sub for example would most likely trade off extension for efficiency. But if the PA sub does need to reproduce more sub bass, we'd need to apply relatively more power down low, which is where more Xmax/driver (or simply more drivers) comes in handy. There's always a trade off in each application and the rules are the same.
The chart is not wrong, but its curves are just estimates. And given the two yellow curves, it would seem BB is taking an even shorter shortcut by evaluating power-excursion limited graphs from an equation or two -- not from its actual models. LEAP 5 or SoundEasy are much better at estimating large signal behaviour.
Best thing to do is take measurements
Those simulations are actually from constant-voltage calculations -- not from constant-power calculations. So at the points were the steady-state impedance of the woofer is at, say, 4 ohms, you do see the output (at those frequencies) given, say, 500W. But at a different frequency where the impedance is not 4 ohms, the applied power is not 500W. At low frequencies in particular, the driver will exceed its motor/suspension excursion limits well before the applied power reaches 500W. A constant-power graph is different from a constant-voltage graph.
Xsus = Xmech (unless otherwise stated).
Best thing to do is take measurements
Those simulations are actually from constant-voltage calculations -- not from constant-power calculations. So at the points were the steady-state impedance of the woofer is at, say, 4 ohms, you do see the output (at those frequencies) given, say, 500W. But at a different frequency where the impedance is not 4 ohms, the applied power is not 500W. At low frequencies in particular, the driver will exceed its motor/suspension excursion limits well before the applied power reaches 500W. A constant-power graph is different from a constant-voltage graph.
Xsus = Xmech (unless otherwise stated).
f4ier,
I know their estimates, but the 6174 is still leading the
AV 15
Raw Driver 1 watt measurement
6174 = 93.88 dB, 1.489%
AV 15 = 88.45 dB, 0.421%
500 watts 8 ohms 6174 = 121 dB 32 Hz
500 watts 4 ohms AV 15 = 114 dB 32Hz
7 dB is a big ratio, among the two woofers
wouldn't you say.
Thanks for the Xsus answer!
So, where did the Xmax 23 mm one way come from?
For the Record, the 6174 measured Xmech is 50
Thanks! I see you've been doing some editing too!
I know their estimates, but the 6174 is still leading the
AV 15
Raw Driver 1 watt measurement
6174 = 93.88 dB, 1.489%
AV 15 = 88.45 dB, 0.421%
500 watts 8 ohms 6174 = 121 dB 32 Hz
500 watts 4 ohms AV 15 = 114 dB 32Hz
7 dB is a big ratio, among the two woofers
wouldn't you say.
Thanks for the Xsus answer!
So, where did the Xmax 23 mm one way come from?
For the Record, the 6174 measured Xmech is 50
Thanks! I see you've been doing some editing too!
Which driver is this?
Running any driver past its Xmax, close to its Xmech, is not recommended, the sound quality would be lower.
Thanks! I see you've been doing some editing too!
Yeah
After ironing out the bugs in SubSim's step- / square-wave-response calculator, my mind is now demanding a bit of idle time 
It's now 3am, g'night and happy speaker building Cheers,
Isaac
Till:
Maybe there is a misunderstanding about when a suspension is called linear:
Linear behaviour is definitely NOT when the suspension's restoring force is constant and independant of excursion.
It is called linear when the restoring force is PROPORTIONAL to excursion. I.e. it is following Hooke's law. Otherwise the excursion, as a function of input power (to be more exact: proportional to input current at a given frequency), would be undefined, specially below fs.
BTW: There are some suspensions that are deliberately nonlinear, i.e. they have a progressive restoring force in order to be more immune against abuse.
Regards
Charles
/having fed 300 watts peak into a 17 cm Dynaudio driver without causing any damage, due to its progressive suspension
Maybe there is a misunderstanding about when a suspension is called linear:
Linear behaviour is definitely NOT when the suspension's restoring force is constant and independant of excursion.
It is called linear when the restoring force is PROPORTIONAL to excursion. I.e. it is following Hooke's law. Otherwise the excursion, as a function of input power (to be more exact: proportional to input current at a given frequency), would be undefined, specially below fs.
BTW: There are some suspensions that are deliberately nonlinear, i.e. they have a progressive restoring force in order to be more immune against abuse.
Regards
Charles
/having fed 300 watts peak into a 17 cm Dynaudio driver without causing any damage, due to its progressive suspension
OK, i understand this. But : from experiments in university i learned, its even hard if not impossible to say exactly the point between proportional and not anymore proportinal force over stretch if you measure steel springs. How is a value given from different manufacturers comparable? xmax before mechanical damage (one time amplitude) is easy to measure. The point of damage with some thousands of excursions near to xmax is possible to measure to, but not so exactly to interpoate, and only done with mechanical parts - not with speakers i belive. "linear" xmax i suspect is something every manufacturer calls like ghe wants, or is there a DIN or ISO or ANSI for measure it? What would say more is distorsion Level over frequency AND SPL. Or SPL over frequency AND different input Watt Levels.
Xmag = Excursion limit due to the magnetic limitations of the driver's motor. Xmag is the displacement at which BL has fallen to 70% of its value at the cone's rest position.
Xsus = Excursion limit due to the driver's suspension. Xsus is the point at which the compliance of the suspension has decreased to 25% of the value at the cone's rest position.
Xmax is simply the shortest of Xmag or Xsus values. Xmag and Xsus do not always give the same throw in both directions -- ie, it may be 10mm foward but only 8mm reversed, so in these cases Xmax is determined by the average of the minimum. this is why Xmax is considered the linear limit---its as far as the cone can move w/o any noticable distortion (based upon the tolerances above)--note; the cone can move further.
Xmech is the maximum mechanical limit---it is not based upon any limitations or standards like Xmax is (based on Xmag and Xsus which are based on %'s of the rest position). Ignore Xmech ratings. Cheap sub companies that actually produce their t/s params yuo can see---5mm of Xmax, 30mm of Xmech.. that means 25mm of NONLINEAR excursion... as mentioned before, sometimes this is wanted in PA systems or to reduce distortion, however in a system where you want things to sound good, not blowup.. ignore Xmech.
-chris
Xsus = Excursion limit due to the driver's suspension. Xsus is the point at which the compliance of the suspension has decreased to 25% of the value at the cone's rest position.
Xmax is simply the shortest of Xmag or Xsus values. Xmag and Xsus do not always give the same throw in both directions -- ie, it may be 10mm foward but only 8mm reversed, so in these cases Xmax is determined by the average of the minimum. this is why Xmax is considered the linear limit---its as far as the cone can move w/o any noticable distortion (based upon the tolerances above)--note; the cone can move further.
Xmech is the maximum mechanical limit---it is not based upon any limitations or standards like Xmax is (based on Xmag and Xsus which are based on %'s of the rest position). Ignore Xmech ratings. Cheap sub companies that actually produce their t/s params yuo can see---5mm of Xmax, 30mm of Xmech.. that means 25mm of NONLINEAR excursion... as mentioned before, sometimes this is wanted in PA systems or to reduce distortion, however in a system where you want things to sound good, not blowup.. ignore Xmech.
-chris
doing non linear speaker simulation requires $1000+ programs like LEAP which most peple cant afford and you need other params like Hag Bl and Hvc which most manufacturers dont give out --- if u get a speaker with a high xmax u can confidently operate it linearly w/o having to worry about exceeding its normal linear range and 'hoping' it wil sound good, bc most ppl dont have the parameters necessary for non linear simulation.
-chris
-chris
zx3chris,
Since you insulted every major speaker manufacter
around the globe that uses Xmech, I only have one
question.
What is the mathamatical Xmax of the Stryke AV 15
I know the Xmax number is always boosted,
however the mathamatical Xmax tells it like it
is.
So ..................... What is it?
Because there's is no way I can see an Xmax
of 23 mm, and Xsus of 30. I need the standard
Xmax or mathamatical Xmax listed in my files.
Please
Thank you
Since you insulted every major speaker manufacter
around the globe that uses Xmech, I only have one
question.
What is the mathamatical Xmax of the Stryke AV 15
I know the Xmax number is always boosted,
however the mathamatical Xmax tells it like it
is.
So ..................... What is it?
Because there's is no way I can see an Xmax
of 23 mm, and Xsus of 30. I need the standard
Xmax or mathamatical Xmax listed in my files.
Please
Thank you
Hi
Peerless says:
Max linear displacement = (Length of coil - Height of gap)/2
Look here: http://www.d-s-t.com/main/tech/displace.htm
Keld
Peerless says:
Max linear displacement = (Length of coil - Height of gap)/2
Look here: http://www.d-s-t.com/main/tech/displace.htm
Keld
i think efficiency is important--but everythign is important.
- if u cant afford plate amps which are 560$ NZ with only 240watt into 4 ohm and even less power into 8ohm..
so i had a choice-efficiency,or lowbass.
this time i chose efficiency,and tuned it low,with 3db of EQ it goes to 30hz.
when i can afford a 500watt amp il buy a shiva or somthing like that..i dont want my amp to clip.
already i have a 100watt kit,on the distortion-power graph it shows that 50watts is clean and 100watts is like infinity distortion so i DONT have 100watts to use
---bridging to 200watt @ 8ohm, into 98db 15inch speaker 160litres.--
- if u cant afford plate amps which are 560$ NZ with only 240watt into 4 ohm and even less power into 8ohm..
so i had a choice-efficiency,or lowbass.
this time i chose efficiency,and tuned it low,with 3db of EQ it goes to 30hz.
when i can afford a 500watt amp il buy a shiva or somthing like that..i dont want my amp to clip.
already i have a 100watt kit,on the distortion-power graph it shows that 50watts is clean and 100watts is like infinity distortion so i DONT have 100watts to use
---bridging to 200watt @ 8ohm, into 98db 15inch speaker 160litres.--
The Stryke AV15 has a 53.34mm long voice coil in a 9.5mm gap. By using the traditional method of (VClength - gapheight)/2 to get xmax, the AV15 gets roughly 22mm each way.
However, the traditional method shown above is quite poor when compared to modern analysis methods such as DUMAX and Klippel. When DUMAX tested, the AV15 got between 23 and 26mm one-way (in real world tests.)
The 23mm xmax Stryke claims is the smaller of the two real world measurements the AV15 achieved, and is quite fair. The 30mm Xsus mentioned for the AV15 is the distance the suspension can travel before hitting 400% of its rest Cms (suspension compliance). This is not where the suspension "bottoms out", mind you and is much more conservative than other manufacturers Xmech ratings, which are usually given at the point where the driver sustains physical damage - where the spider rips away from the voice coil assembly, or where the voice coil bottoms against the back plate, or where the surround is stretched to its limit and the glue joint between the surround and basket/cone starts to deteriorate.
The two numbers Stryke gives for the AV15 are good real-world guidelines for the driver - you can plan to have at least 23mm of linear throw each way, and you can plan to use the driver to about 30mm each way without the suspension restoring force becoming too great.
Xsus and Xmech in this case are not interchangeable. To do a valid comparison between the Xsus given by Stryke and the Xmech given by other manufacturers, you need to know the exact conditions the Xmech was measured under. Xsus is always more conservative than Xmech.
However, the traditional method shown above is quite poor when compared to modern analysis methods such as DUMAX and Klippel. When DUMAX tested, the AV15 got between 23 and 26mm one-way (in real world tests.)
The 23mm xmax Stryke claims is the smaller of the two real world measurements the AV15 achieved, and is quite fair. The 30mm Xsus mentioned for the AV15 is the distance the suspension can travel before hitting 400% of its rest Cms (suspension compliance). This is not where the suspension "bottoms out", mind you and is much more conservative than other manufacturers Xmech ratings, which are usually given at the point where the driver sustains physical damage - where the spider rips away from the voice coil assembly, or where the voice coil bottoms against the back plate, or where the surround is stretched to its limit and the glue joint between the surround and basket/cone starts to deteriorate.
The two numbers Stryke gives for the AV15 are good real-world guidelines for the driver - you can plan to have at least 23mm of linear throw each way, and you can plan to use the driver to about 30mm each way without the suspension restoring force becoming too great.
Xsus and Xmech in this case are not interchangeable. To do a valid comparison between the Xsus given by Stryke and the Xmech given by other manufacturers, you need to know the exact conditions the Xmech was measured under. Xsus is always more conservative than Xmech.
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