Hi there,
Are there any circumstances under which it could be feasible to make a tapped horn based on a 12" subwoofer with only a 3" voice coil? It would likely be driven fairly hard as it's for live sound use. The only factor I can think of which might make it possible is the higher tuning, which would like to be about -3dB at 50-55hz.
thanks
Are there any circumstances under which it could be feasible to make a tapped horn based on a 12" subwoofer with only a 3" voice coil? It would likely be driven fairly hard as it's for live sound use. The only factor I can think of which might make it possible is the higher tuning, which would like to be about -3dB at 50-55hz.
thanks
"Fairly hard" is an ambiguous amount of power.
Many tapped horns have been made using the Eminence LAB12 (LAB stands for Live Audio Board), which uses a 2.5" voice coil.
Live sound usually has much higher crest factors than much of the pre-recorded material popular with DJs.
The average power for live generally is under 1/8th the peak, while for some EDM and hip hop the crest factor is only 3dB, same as a sine wave, 8 times more.
Voice coils can be cooked at any frequency, but it's more likely to happen with sustained input at the excursion and impedance minima, where the most power is converted to heat with the least amount of vent cooling.
Many tapped horns have been made using the Eminence LAB12 (LAB stands for Live Audio Board), which uses a 2.5" voice coil.
Live sound usually has much higher crest factors than much of the pre-recorded material popular with DJs.
The average power for live generally is under 1/8th the peak, while for some EDM and hip hop the crest factor is only 3dB, same as a sine wave, 8 times more.
Voice coils can be cooked at any frequency, but it's more likely to happen with sustained input at the excursion and impedance minima, where the most power is converted to heat with the least amount of vent cooling.
My POC3 TH uses a 12" driver with a 3" coil. Unfortunately it's also tuned to around 39 Hz, so its output is more excursion than power limited.
You should be fine with using a 12" driver with a 3" coil. Just watch what its predicted excursion in the passband looks like.
You should be fine with using a 12" driver with a 3" coil. Just watch what its predicted excursion in the passband looks like.
Obviously a bigger voice coil will give less thermal compression - better power handling.
The SS15 used the 3015 kappalite which is a 3" coil. It gave killer performance up to a certain level but eventually compressed, probably due to the driver & the lightweight construction.
As Brian said a lower tuning will be limited by excursion - and a higher tuning will often be power limited.
There are far more variables then just the voice coil size.
Running sims in Hornresp will allow you to evaluate excursion & filter settings with your chosen cabinet & driver.
You could find that the driver you are concidering is just completely unsuitable!
If the response is flat enough & loud enough for your uses and fits the budget go for it!
The SS15 used the 3015 kappalite which is a 3" coil. It gave killer performance up to a certain level but eventually compressed, probably due to the driver & the lightweight construction.
As Brian said a lower tuning will be limited by excursion - and a higher tuning will often be power limited.
There are far more variables then just the voice coil size.
Running sims in Hornresp will allow you to evaluate excursion & filter settings with your chosen cabinet & driver.
You could find that the driver you are concidering is just completely unsuitable!
If the response is flat enough & loud enough for your uses and fits the budget go for it!
Thanks
Yeah I was aware there are other factors that determine how strong the driver is.. I just thought this one might be particularly important and might mean that the speaker is not going to be able to survive a reasonable lifetime.
I’ve run Pmax in horn resp and it appears to perform similarly to the 4” vc drivers I’m looking at.
On power compression- has anyone ever tried using a fan or something to cool the driver? Or is that a bit of a wacky idea?
Yeah I was aware there are other factors that determine how strong the driver is.. I just thought this one might be particularly important and might mean that the speaker is not going to be able to survive a reasonable lifetime.
I’ve run Pmax in horn resp and it appears to perform similarly to the 4” vc drivers I’m looking at.
On power compression- has anyone ever tried using a fan or something to cool the driver? Or is that a bit of a wacky idea?
The Community Airforce series did use forced air cooling in (IIRC) the mid 1990's, but the product didn't take off.
Tom Danley used a centrifugal blower fan on the Bass Tech servo-motor-drive front loaded bass horn subs in the mid 1980s.
Wayne Parnham made a cooling plug and heat exchanger plate for the LAB12s used in his 12Pi front loaded bass horn around 2005.
Since then, loudspeakers with far better passive cooling have been designed.
Wayne Parnham made a cooling plug and heat exchanger plate for the LAB12s used in his 12Pi front loaded bass horn around 2005.
Since then, loudspeakers with far better passive cooling have been designed.