Subwoofer damping
I just read Dukes comments and I still don't get it ... a variovent is supposed to allow for a smaller box than the woofer would normally require....but the box itself is already so huge. Maybe this design is close to an infinte baffle subwoofer with IB type drivers(excursion protected)? |
The box must be a folded horn or bass bin....it is too big for acoustic suspension. The problem with folded horns is the out of band noise from cabinet vibration (two parallel sides along the horn) and issues at sharp angles as you turn corners. You may need to open them up as something may be loose (perhaps glue has dried out and cracked when it was stored or something warped due to humidity/damp). Bass bins are what would be used in a disco bar...(a type of band pass design) See this for an explanation |
For example, a variovent with a high-end TC Sounds woofer, like the ones used in JL Audio subs, would probably work very well. Yes but even the LMS-Ultra 18 with 4 inch Voice Coil and 30 mm Xmax is suited to a 6.5 cu Ft sealed box - this is one of the best subwoofer drivers in the world - so why the 20+ cu ft that Wavetrader has? (Surely they are folded horns/bass bins?) BTW - I heard TC Sounds is bankrupt does this mean JL audio will not be able to use their drivers anymore? |
If this is the case, then you have a band-pass enclosure. And if it uses Scan-Speak drivers . . . the vast majority of which have a pretty low Qes . . . that means that this is probably a sixth-order bandpass enclosure. Also, a 6th-order bandpass box, with two 16" drivers, tuned to low frequencies, could easily be as freaking huge as what you have. Kirkus - you are thinking the same way I am...surely this has got to be bandpass... |
the present crossover does'nt provide a low pass filter IMHO, whay you may need is a "high pass filter" to prevent ultra LF reaching the drivers...I'd cut everything below 30 Hz....I don't think you have a "subwoofer" in the modern sense - I think you have something that was intened and designed to enhance bass reprodution in a large space like a club - it probably works best from 40 to 100 Hz. |
Interesting.......the NHT X2 should provide the needed flexibility I am not familiar with it. However a word of caution - I don't see high pass for removing ultra LF on the specifications. "50 Hz" is the lowest high pass filter which sounds like this is intended to provide a feed to mains. You might need adjustable high pass at 10 to 40 Hz and adjustable low pass set from 50 to 90 Hz with various filter slope options. Although I would expect the crossover that originally came with your box would take care of this...could one of the caps have dried out..you know certain caps don't like to be left in storage and will easily blow the first time you fire them up....that might be your only problem... a dud Cap... |
Crossover Frequency 50Hz, 80Hz, 110Hz high pass With a 12 db slope this will be down 12 db at 25 HZ and down 24 db at 12.5 Hz... As I mentioned, this filter look like it was designed for the feed to main speakers. 50Hz-140Hz adjustable low-pass filter This filter appears to be the feed for your subwoofer and it does not appear to have protection or a filter for ultra LF (which is normal because a modern subwoofer usually can handle ultra LF often having momentary gain reduction built in etc.) If you look at the behringer device then you will see it has a limiter to protect bass woofers...this could be useful. I am not familiar with NHT x2 - sorry - I just thought you might need pro bass management seeing as what you have was previously in a disco bar,,, |
