PEARL PR-2 Woofers
PEARL PR-2 8" woofer (note: PEARL's web-site is still pretty sparse)
These are very rare unique hand built bass drivers in Calgary by Bill Perkins. The picture above is of the larger magnet version. The basket, motor structure is designed so that a bolt can go thru the pole piece and attach the speaker to the enclosure. I plan to take advantage of this to bolt the speakers together. That, the massive baskets, steel rod beween the respective bolt holes, and a small, rigid enclosure should go a long way towards realizing the full potential for push-push loading to cancel the Newtonian effects of the moving cone. They will load a TL.
The 4 units I have are older, superceeded small magnet version -- the olny reason I was able to get them was because they were surplus.
|
|
||||||||
|
A |
B |
C |
D |
Average |
||||
|
Electrical/Mechanical Parameters |
||||||||
|
Revc |
(DC VC Res ) |
3.6 |
3.6 |
3.6 |
3.6 |
3.6 |
Ohm | |
|
Fo |
(Res Freq ) |
31.3 |
30.4 |
29.5 |
26.6 |
29.5 |
Hz | |
|
Zo |
(Zmax at Fo) |
36.4 |
39.6 |
45.5 |
67.7 |
|
Ohm | |
|
Sd |
(Piston Area) |
0.02 |
0.02 |
0.02 |
0.02 |
0.02 |
sqM | |
|
BL |
(Flux x Length) |
6.8 |
7.1 |
8.4 |
8.5 |
|
TM | |
|
no |
(Ref Effncy) |
0.65 |
0.72 |
0.87 |
0.78 |
|
% | |
|
SPLo |
(SPL at 1W ) |
90.2 |
90.6 |
91.4 |
90.9 |
|
dB | |
|
Qms |
(Mech Q) |
2.93 |
2.82 |
2.46 |
3.52 |
|
||
|
Qes |
(Elec Q) |
0.322 |
0.282 |
0.212 |
0.198 |
|
||
|
Qts |
(Total Q) |
0.290 |
0.256 |
0.195 |
0.187 |
0.232 |
||
|
Vas |
(Acous Vol) |
70.5 |
74.9 |
74.1 |
85.0 |
76.1 |
Litre | |
|
Cms |
(Compliance) |
1242.0 |
1319.0 |
1305.4 |
1496.8 |
|
uM/N | |
|
Mms |
(Total Mass) |
20.8 |
20.8 |
22.3 |
24.0 |
|
Gram | |
|
Mmd |
(DiaphmMass) |
19.2 |
19.2 |
20.7 |
22.4 |
|
Gram | |
|
|
||||||||
|
Motor Impedance Parameters |
||||||||
|
Levc |
(Induc at 1kHz) |
0.90 |
0.850 |
0.75 |
0.74 |
|
mH | |
|
Levc |
(Induc at 20kHz) |
0.36 |
0.35 |
0.32 |
0.32 |
|
mH | |
|
Krm |
(Resistance Cons) |
9.9 |
6.7 |
4.5 |
6.0 |
|
mOhm | |
|
Kxm |
(Reactance Cons) |
12.7 |
11.2 |
9.1 |
8.8 |
|
mH | |
|
Rem |
(Res at 1kHz) |
3.4 |
3.0 |
2.7 |
2.7 |
|
Ohm | |
|
Rem |
(Res at 20kHz) |
24.7 |
24.5 |
24.2 |
22.3 |
|
Ohm | |
|
Erm |
(Resis Expont) |
0.67 |
0.70 |
0.73 |
0.70 |
|
||
|
Exm |
(React Expont) |
0.70 |
0.71 |
0.71 |
0.72 |
|
||
|
Measurements by Aaron Drabbitt LMS Version 3.72 / Delta Mass Curve Pair / Mass Added to Cone = 16.00 Gram |
||||||||
More info on the line for these here.
[ Back to the TL Speaker Page ]