i have tested the 18tbx46 in this housings and they worked well. The 18tbx46 sounds not as god as the oberton 18 xb 700 between 80-120hz, but from 40-80/100 hz it worked very well.
http://www.paforum.de/phpBB/viewtopic.php?t=52047&highlight=oberton
no it isn't 
the cad programm generates the 252,03 mm ...
+- 1 mm should be no problem.
I think this is a box problem because the speaker is 2000 wrms and that is the reasen why I want other boxes. Do you agree?
We all are absolutely sure: 18TBX46 will never handle an RMS load of 2000W. This may be the pulse peak load for milli seconds, no more. It likes to work in WSX foldet Horns. :wink:
hello!
tja, what means better in your eyes?
double electrical output means 3 db more in acustical output - in theory!
in reality there´s powere compression.
it´s ok to call it headroom - for live-music maybe it´s an advantage.
in your case it isn´t necessary, i think.
I don't understand this:
Benötigte MULTIPLEX Platten: 3x 556mm x 626mm Rückwand, LS1&2 Platte.
Why 3 times?
... because of the special forced baffle :wink:
Hi thoving,
bottom line is
speaker destruction can only be avoided by headroom, or levelling / limiting .
We are discussing those amp clip issues in two forums and all agree in using stronger amps when limiting or other techniques are not in place. So the bigger amp can never be wrong.
I used to setup an 18" bass horn and mid/hi horns (3way, active) for drumfill use (you call it a drum monitor in other countries, right ?).
The bass section consistet of a front loaded bin featuring RCF 18/851KN or SAMMI SR18AW500G, driven by an CROWN MT1200-Amp.
Still, it was only sufficient when signal was limited. The sound material was / is Metal, the very loud drummer "singing" himself thru a head mike ...
I switched over to a 2KW-amp, delivering at least 1400 W / 8 ohms, limited. The stack sounds ok now.
Hello thoving,
>>Winding Depth 25 mm (1 in)
Magnetic Gap Depth 12 mm (.47 in)<<
This will give you the real x- max, it is 6,5 mm like the most 18" chassis on the market. It is easy to view the excursion in bright light, a little white dot (white tape) on the cone will help. Compare the excursion with a ruler, held in 90° to the baffle. If you reach an overexcursion of about 2mm (means 17 mm peak to peak), in the used cabinet, with defnitely not clipping Amp, then the amp has enough power. Test this with different kinds of music, or short sinewave Bursts. Please use earplugs while testing.
For save operation you have to make shure, that the amp never goes into clipping. Some Amps have a cliplimiter, thats a good way, but if the cliplimiter is permanently limiting the coil will burn...
If the only way to avoid clipping is the use of a big Amp, then keep in mind that overexcursion generates distortion and shortens the lifetime of the speaker. But with clipping amp the speaker will fail within minutes.
greetings
Hello thoving,
B&C gives you the real data in addition to "marketing data". The hopefully linear electrical driven excursion ends with the coil leaving the gap. For this chassis to one side 6,5 mm, or 13mm peak to peak. In case of low acoustic radiation resistance a little bit of overexcursion is acceptable, the distortion does not sudenly rise in audible katastropy. But the 9mm "x-max" in the datasheet marks 10% distortion according to AES measuring method (i think). The 11 mm will sound rough (i am sure).
The tape... i think with a high quality chassis the cone motion is the same at any place on the cone, so put it where you can see it well.
With the limiter in the digital x- over and the limiter in the amp you have the equipment to avoid clipping, check out witch sounds better to you with your speaker. Maybe a combination is it, watch the excursion, listen how it sounds to you. If you cannot reach overexcursion with your amp put it in bridge mode for testing one speaker.
greetings
