I really don't think there is a "sub norm", there are people not satisfied unless hitting single digit LF at 120 dB, and folks that think a Bose wave radio is as big and low as they want.
regarding this, I am only relating to professional PA, which is where we get these top pro woofers from
no doubt the Xmax have gone up
and pole plate thickness is also increasing
all together this means loss of efficiency
still, the larger Xmax means SPL can be maintained, or even increased
so, instead Fs is raised to push up efficiency
looks to me like last years pro woofers might be better for home use than next years pro woofers
but ofcourse only speculation
What are you powering that with? I play bass as well.
I agree that lighter duty pro drivers are better for home use. I'm building around b&c's cheapest 18". Four of them. Sensitive and smooth extended response.
OT ... answered by PM
maybe, but I will never buy cheap semi pro woofers again
but did get this one cheap, on sale
GOSH! ... 18" really is BIG
(unfortunately they also delivered a damaged one
)just getting excited, sorry
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B&C posts the peak to peak "excursion before damage" for most of their drivers, but not in the TS parameters.
Excursion before damage is the same as Xmech, or Xlim, but like Xmax, are one way, not peak to peak.
Xmech can not be assumed to be a given doubling of Xmax, some drivers have very little difference between the two, others more than double.
I generally use the Xvar figure for figuring acceptable excursion as the speaker will still have little distortion up to Xvar.
Note that the 15TBW100 has a longer magnetic gap depth and shorter coil depth, giving it a longer Xvar than the 15SW115, yet has a shorter Xmech.
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yep, I've noticed that on a couple.
So "xmech" is only listed in the comments section on *some* of the models.
That being said, givin ricci's High power free air excursion tests, I doubt xmech can ever be reached with many of the BC woofers.
"This driver is relatively quiet until about 1" peak to peak and starts to make some suspension and motor noise from there. At large excursions the motor does emit some noise and there is a very large amount of air flowing out of the pole piece and from under the spiders. At about 1.5" peak to peak the driver starts making a lot of suspension and motor noise. Further increases in input power produce little increase in excursion indicating that the suspension and or motor are not responding linearly to further power increases and resulting in excess heat to the voice coil. It should be noted that while the manufacturers Klippel verified xmax is about 15mm the usual calculation of gap height minus the the height of the coil wind, divided by two results in only 9.5mm. Physical hard bottom Xmech is supposed to be 30mm inward but it is unlikely that the driver can physically produce this much excursion judging from obscene amounts of power being dumped into the driver with test tones in free air. The amplifier is rated at 1400w into the load in the video and is clipping at the highest excursions shown. "
21sw152-4free.mp4 Video by Data-Bass | Photobucket
So "xmech" is only listed in the comments section on *some* of the models.
That being said, givin ricci's High power free air excursion tests, I doubt xmech can ever be reached with many of the BC woofers.
"This driver is relatively quiet until about 1" peak to peak and starts to make some suspension and motor noise from there. At large excursions the motor does emit some noise and there is a very large amount of air flowing out of the pole piece and from under the spiders. At about 1.5" peak to peak the driver starts making a lot of suspension and motor noise. Further increases in input power produce little increase in excursion indicating that the suspension and or motor are not responding linearly to further power increases and resulting in excess heat to the voice coil. It should be noted that while the manufacturers Klippel verified xmax is about 15mm the usual calculation of gap height minus the the height of the coil wind, divided by two results in only 9.5mm. Physical hard bottom Xmech is supposed to be 30mm inward but it is unlikely that the driver can physically produce this much excursion judging from obscene amounts of power being dumped into the driver with test tones in free air. The amplifier is rated at 1400w into the load in the video and is clipping at the highest excursions shown. "
21sw152-4free.mp4 Video by Data-Bass | Photobucket
Here is the spec sheet for the 15tbw100-4, along with the spec sheet for the 15SW115-4, thanks to the guys at B&C!
I don't doubt that the LAB15 will play lower as you had stated previously, however I needed the power handling of the B&C to be able to safely handle what my amp can output.
F3 for the Dayton HO's was around 33.5hz, with the 15TBW100-4's it's about 30.75hz. The B&C's are about 1 db less sensitive at 40hz, but are 6 db more sensitive at 150hz, which should provide for some greatly improved kick drum action from the subs. I currently low pass at 190hz, 4th order BW, but may switch to a lower order.
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Very nice Faital Pro 15XL1400. Seriously considered it in the 4 ohm version, but it would have been $150 each more than the 15TBW100 for about the same power handling and output, though much lighter.
Seems about right. In my model I see an excursion peak of 15mm or so at 90v at 50 hz, 9.5 ohms, 850w. Power peak is 2500w at 35hz (tuning freq) at 90v, 3.25 ohms. When going at near max volume, 112-115 db at listening position, the amount of driver noise shown in the video will be nowhere near noticeable, especially when in a box.
Was just a matter of comparing apples to apples was all. 18 Sound has the 18" NLW9601 at 1130Sd while BC has a generic 1210. Not a big deal really was just curious was all.
Thinking about building a few TH designs but trying to narrow it down to a pair of cabinets. When simulating I am just seeing what they can do with correct specs.
Thinking about building a few TH designs but trying to narrow it down to a pair of cabinets. When simulating I am just seeing what they can do with correct specs.
A little late in the game but RCF - LF18X451
Again it may not be cheaper depending on location but here it's £299 where the B&C is almost double that!
13.5mm of Xmax, Thiele Small parameters VERY similar to the B&C 18SW115. It models almost identical (tiny fractions of a dB) and the cone is 260g which should be reasonable for load bearing applications such as horns.
I seem to remember another forum member finding this one when I was looking at bass reflex, and it has become the ideal candidate for my latest 6th order bandpass concept.
Again it may not be cheaper depending on location but here it's £299 where the B&C is almost double that!
13.5mm of Xmax, Thiele Small parameters VERY similar to the B&C 18SW115. It models almost identical (tiny fractions of a dB) and the cone is 260g which should be reasonable for load bearing applications such as horns.
I seem to remember another forum member finding this one when I was looking at bass reflex, and it has become the ideal candidate for my latest 6th order bandpass concept.
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Have you tried ebay ".com". Parts express does stuff on there with better shipping prices than were available a year ago. For me in new zealand I can have the 18TBW100 landed incl import duties(GST) for 50 pound more than what your 299.
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