NSB Project #1: Small Sealed Box
Maryann and Susan (sisters) decided to build small sealed boxes around single NSB drivers (PE #269-570) also nicknamed the 90 cent wonders.  The pictures below chronicle their progress.  Tonight we auditioned them.  Very nice, a bit "airy," clean and smooth.  The Clio response graphs are included below, as well.  They could use a baffle step compensation circuit and a small subwoofer (the sisters are going to start the accompanying sub in a few days).  Here are some details for those who might want to copy their design:
Our measured T-S parameters:                                                             Box dimensions:
                                               Fs          104 Hz                                      0.179 cubic feet air inside
                                               Qms       5.021                                        all butt joints
                                               Vas         3.27 L                                      1/2 inch mdf on 4 surfaces
                                               Cms        0.721                                       1/2 inch particle board on 2 surfaces
                                               Mms       3.2 g
                                               Rms       0.421 kg/s                                 12.25 inches high
                                               Xmax      1 mm                                        8 inches deep
                                               P-Diam   84.85 mm                                  5.3 inches wide
                                               P-Vd      0.00565 L
                                              Qes         0.915                                         1 shelf brace about 60% of the distance from
                                              Re           6.9 ohms                                                     bottom to top ends
                                              Le           0.58 mH                                    interior joints sealed with silicon rubber
                                              Z            8.3 ohms                                    all inner walls lined with PE #268-035
                                             BL           4.0 Tm
                                             Qts          0.774                                         stuffed 70% with fiberglass bare insulation
                                   1-watt SPL/m     88 dB                                        outside covered with PE vinyl #260-014

                                             Thick cardboard trim tab was removed from the edge of the driver surrounds using a
                                             razor utility knife.  This caused the surround to separate from the cardboard beneath it
                                             and the frame, so we reglued it using PE # 340-076
The two response curves represent overlays of the measurement of each box separately.  It is clear that about 4 dB of BSC wouldn't hurt at all.  One should ignore the readings below 100 Hz as they are subject ot random room noise and other artifacts.  The girls were very pleasantly surprised at the quality of the sound these speakers produce.

Next project to be completed (in a couple of days) is Ami's 6 driver-per- sealed box mini line array.
The bandpass subwoofer designed to support the NSB satellites from 140 Hz and down.  An 8 inch Vifa (unknown 4 ohm model, donated by dB) plus a 150 watt PE plate amp melds very well with the NSBs. 
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