Mid-bass Horn calculations (BD-Design)

by Marco, Bern, Sunday, August 12, 2012, 21:36 (4273 days ago)

Hi to all, I (Marc) am new here and planning a horn-setup. Bert's tutorial is very useful. Some basic decisions remain before the individual components can be planned correctly.
Tapped Horn : BC 18PS100, TH with one fold. 30-130 Hz ( details later)
Mid-bass horn : BC 12NBX100 ( http://www.bcspeakers.com/product.php?id=366) with spherical wave horn calculated in hornresp, below are the data ( I couldn't upload the text-file, my fault ?). Back chamber should be 3.8 L, lower roll-off was better with 6-8 L. Throat chamber is set at 0.7 L. I will make the throat chamber with MDF, does the form matter ? How do you measure the air volume of the basket btw ? Total driver volume is 3 dl3. Avantgarde Acoustics ( kompendium_der_horntechnik.pdf) writes that the throat chamber is a 6 dB high pass filter, high or low ? Smaller throat chamber increases the upper range in hornresp. I will build a mold and make the horn in fiberglass.
ID=28.00
Ang=2.0 x Pi
Eg=2.83
Rg=4.00
Fta=89.26
S1=85.00
S2=11300.78
Sph=92.20
F12=120.00
S2=0.00
S3=0.00
L23=0.00
AT=6.54
S3=0.00
S4=0.00
L34=0.00
F34=0.00
S4=0.00
S5=0.00
L45=0.00
F45=0.00
Sd=531.00
Bl=25.60
Cms=1.27E-04
Rms=2.49
Mmd=30.63
Le=1.40
Re=5.10
GCd=1
Vrc=7.00
Lrc=8.00
Fr=0.00
Tal=0.00
Vtc=500.00
Atc=400.00
Pmax=100
Xmax=10.0
Comment=12NBX100
MF and HF horns - later. I would wellcome any comments and critics. Thanks !