ok, so after revisiting the system tonight. i established my settings on the amp were for a microphone ( i had it setup for public speaking a few months back. )
so i fixed those, and omg. in love all over again. the depth has returned, they no longer drive full range sound. and they rumble like no other!
im attempting to sell my first cab, what i call the SS12. not sure on selling rules, so i wont post it here. if i can sell it off, im hoping to build two more SS15 cabs with the money i get
so i fixed those, and omg. in love all over again. the depth has returned, they no longer drive full range sound. and they rumble like no other!
im attempting to sell my first cab, what i call the SS12. not sure on selling rules, so i wont post it here. if i can sell it off, im hoping to build two more SS15 cabs with the money i get
Hi klampy,
The top cabs are inspired by a jbell design which is hidden somewhere in this huge thread. It's a 50l bass reflex / front loaded horn design for the Eminence Beta 12A-2, with the Eminence PSD-2002 Tweeter in a Dayton 12" waveguide.
Unfortunately, I ended up leaving the subwoofer at home for the weekend, so just the tops got field tested. But I do have one extra pic of the sub to show, revealing the design with the cone volume correction and somewhat added path length.
thanks for that JWMbro.
so i sold my "SS12" and now the cash is burning a hole in the pocket, ill be visiting bunnings and making some sawdust this coming thurs or friday (or both?) and knocking up two more SS15 cabs. on the way to saving up for two more JB1500N's
anyone able to tell me if four SS15s will comfortably fill a hall the size of two basketball courts with enough sound to satisfy 1000people?
so i sold my "SS12" and now the cash is burning a hole in the pocket, ill be visiting bunnings and making some sawdust this coming thurs or friday (or both?) and knocking up two more SS15 cabs. on the way to saving up for two more JB1500N's
anyone able to tell me if four SS15s will comfortably fill a hall the size of two basketball courts with enough sound to satisfy 1000people?
got my JB1500N's today
Im just a Little concerned with xmax only being 6mm and then saying they can be run up to 1200watt, not that I have crunched the numbers or anything.
im not sure if youre saying this is a bad thing or not, but so far, im yet to really push them, but they seem to be doing exactly what i want them to... they flex nicely when unfiltered. and, i will be running them with a 50hz filter on the eq, and on the amp is a 30hz subsonic filter, which i will have active.
As far as I know the tapped horn design requires large xmax numbers to reach its power handling potential or they will just break apart trying to get there. The Ande and Eminence drivers have a fair bit higher xmax than your JB. I dont claim that I know everything about xmax and how it matters and what numbers are bad/good, there are much more knowledgeable people here for that.
I will be building some SS15 soon with ande drivers and was looking at your drivers since they are cheaper however the smaller xmax figure has put me off, given what little I know about it.
I will be building some SS15 soon with ande drivers and was looking at your drivers since they are cheaper however the smaller xmax figure has put me off, given what little I know about it.
11mm x-max=
If the Ande were to have an actual 11mm one way x-max the coil would be so long that it would easily bottom, more likely the coil is 22mm tall, and take from that the gap height, commonly ~6-8mm on cheap woofers leaving you basically the same actual x-max as the JB1500N.
If the Ande were to have an actual 11mm one way x-max the coil would be so long that it would easily bottom, more likely the coil is 22mm tall, and take from that the gap height, commonly ~6-8mm on cheap woofers leaving you basically the same actual x-max as the JB1500N.
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After seeing the 10mm top plate 11mm x-max is within the realm of possibility...
Not to take a poo on the Ande...
I can't find complete specs for these drivers but what I see for the Ande, the 10mm top plate is thick and so I'd venture a guess that the coil is ~17mm long... (17/2)+(10/4) would put it in the 11mm ballpark. Having no idea about the JB1500N, the straight overhung number guess is 18mm coil and 6mm gap plate as it looks pretty thin. X-max is a numbers game and both woofers are probably Chinese in origin so short of measuring them yourself you are flying blind. The Ande is stronger on paper and due to the thick top plate it also sports ~1.5mm more x-max as a calculated guess. How long the coils actually are is hard to know without tearing a driver apart...
Not to take a poo on the Ande...I can't find complete specs for these drivers but what I see for the Ande, the 10mm top plate is thick and so I'd venture a guess that the coil is ~17mm long... (17/2)+(10/4) would put it in the 11mm ballpark. Having no idea about the JB1500N, the straight overhung number guess is 18mm coil and 6mm gap plate as it looks pretty thin. X-max is a numbers game and both woofers are probably Chinese in origin so short of measuring them yourself you are flying blind. The Ande is stronger on paper and due to the thick top plate it also sports ~1.5mm more x-max as a calculated guess. How long the coils actually are is hard to know without tearing a driver apart...
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just thought id bring the pic from last page forward
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theyre definately different.
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theyre definately different.
An externally hosted image should be here but it was not working when we last tested it.
The JB1500N Sd 908cm² seems a bit inflated... that's 340mm∅, the cutout is 355mm∅
The calculated Sd for the JB1500N is 878.261201056914cm²... still looking a bit fake...
BL²/Re=73.4563636363636... /Sd=83.6384023754706
The Ande driver calculates to be 841cm², more realistic...
BL²/Re=83.2654545454546... /Sd=99.0076748459627
The Ande is stronger but I don't think x-max is almost double...
The calculated Sd for the JB1500N is 878.261201056914cm²... still looking a bit fake...
BL²/Re=73.4563636363636... /Sd=83.6384023754706
The Ande driver calculates to be 841cm², more realistic...
BL²/Re=83.2654545454546... /Sd=99.0076748459627
The Ande is stronger but I don't think x-max is almost double...
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"the 10mm top plate is thick and so I'd venture a guess that the coil is ~17mm long... (17/2)+(10/4) would put it in the 11mm ballpark."
A 17mm coil would have 7mm overhang, so (7/2)+(10/4)=6mm x-max.
The JBL 2226H has a 19.05mm coil, 8.1mm top plate, so (10.95/2)+(8.1/4)=7.5mm (JBL says 7.6mm).
A 17mm coil would have 7mm overhang, so (7/2)+(10/4)=6mm x-max.
The JBL 2226H has a 19.05mm coil, 8.1mm top plate, so (10.95/2)+(8.1/4)=7.5mm (JBL says 7.6mm).
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The thought is that it represents the 70% Bl point with only 75% of the gap filled with coil.
The old standard was coil overhang/2 plus 10% of the total coil length, but this did not predict the 10% distortion point (especially with the newer thicker top plates) and required a current probe and an oscilloscope to observe the distortion in the current waveform (and some guessing as to what constituted 10% distortion).
Most of the pro sound speaker manufacturers are following the gap height/4 method, so it is usually and apples vs apples comparison.
Faital Pro chooses not to follow, and uses to use Xmax = [(winding depth - magnetic gap depth) / 2] + (magnetic gap depth / 3) , which tends to make their specs look better (that what they probably are).
The gap height/4 method correlates well with Du-Max measurements for 70% Bl.
An Aura/TC Sounds 18 has an underhung 3" gap with a 1.5" coil, they claim a geometric x-max of 19mm and a 70% Bl of 31mm (30% of the coil out of the gap). Mechanical noise on the back side of the driver starts to climb above about 1.5" P-P travel.
The old standard was coil overhang/2 plus 10% of the total coil length, but this did not predict the 10% distortion point (especially with the newer thicker top plates) and required a current probe and an oscilloscope to observe the distortion in the current waveform (and some guessing as to what constituted 10% distortion).
Most of the pro sound speaker manufacturers are following the gap height/4 method, so it is usually and apples vs apples comparison.
Faital Pro chooses not to follow, and uses to use Xmax = [(winding depth - magnetic gap depth) / 2] + (magnetic gap depth / 3) , which tends to make their specs look better (that what they probably are).
The gap height/4 method correlates well with Du-Max measurements for 70% Bl.
An Aura/TC Sounds 18 has an underhung 3" gap with a 1.5" coil, they claim a geometric x-max of 19mm and a 70% Bl of 31mm (30% of the coil out of the gap). Mechanical noise on the back side of the driver starts to climb above about 1.5" P-P travel.
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Take a 17mm Voice Coil and inseret it into the 10mm tall gap across the poles.
The Xmax used to be stated as [17 - 10] / 2 = 3.5mm
You are saying that by accepting a much lower BL and the distortion that ensues from the lower BL that Xmax is now "longer".
eg.
low BL version of Xmax = [17 - 10] / 2 + 10/4 = 6mm
or very low BL version of Xmax = [17 - 10] /2 + 10/3 = 6.83mm
Balderdash !!!
Xmax is the linear excursion where the Voice Coil is still inside the major part of the gap flux. Yes there are fringes at the edges of the gap where the flux is almost as high as within the gap. So the 3.5mm result will be an underestimate of the measurable Xmax.
Xmax cannot be increased by >70% (6 cf.3.5) or by >95% (6.83 cf 3.5) just because the manufacturers/retailers want to exaggerate the performance of their product.
Lies and damn lies seems little different from disreputable manufacturers' claims when it comes to audio product.
The Xmax used to be stated as [17 - 10] / 2 = 3.5mm
You are saying that by accepting a much lower BL and the distortion that ensues from the lower BL that Xmax is now "longer".
eg.
low BL version of Xmax = [17 - 10] / 2 + 10/4 = 6mm
or very low BL version of Xmax = [17 - 10] /2 + 10/3 = 6.83mm
Balderdash !!!
Xmax is the linear excursion where the Voice Coil is still inside the major part of the gap flux. Yes there are fringes at the edges of the gap where the flux is almost as high as within the gap. So the 3.5mm result will be an underestimate of the measurable Xmax.
Xmax cannot be increased by >70% (6 cf.3.5) or by >95% (6.83 cf 3.5) just because the manufacturers/retailers want to exaggerate the performance of their product.
Lies and damn lies seems little different from disreputable manufacturers' claims when it comes to audio product.