On the Bench
The measurements at 31.5 Hz, 40 Hz, and 50 Hz were taken at
12" from a spot in between both woofers. All distortion measurements
and response curves - except where specified - were taken with the port plug
At 31.5 Hz, and 100 dB, THD+N was less than 10%, which is
good for woofers in a floor-standing speaker.
At 40 Hz, THD+N went down to about 5%.
And, at 50 Hz, 4% THD+N.
The next two graphs are taken from the midrange driver,
again, at 12".
A 1 kHz input signal gave less than 0.2% THD+N.
IMD with 1 kHz and 1.5 kHz input signals was 0.014%. The
software looks at the highest of the two fundamentals and uses all spurs,
not including the other fundamental, within 500 Hz (± 250 Hz), to give the resulting IMD
number. The A+B peak (fundamental A plus fundamental B), at 2.5 kHz, is 76 dB
below the largest fundamental (fundamental A at 1 kHz). The B-A peak, at 500
Hz, is 73 dB below fundamental A.
The next three graphs were taken from the tweeter, at 12".
At 5 kHz and 6 kHz input signals, IMD was less than 0.006%.
The A+B peak, at 11 kHz, is 48 dB below fundamental A. The B-A peak, at 1
kHz, is 60 dB below fundamental A.
At 10 kHz, there were only two harmonics, the second and
third, with THD+N at less than 0.6%.
Using 10 kHz and 11 kHz input signals, IMD was less than
0.006%. The A+B peak, at 21 kHz, is 52 dB below fundamental A. The B-A peak,
at 1 kHz, is 69 dB below fundamental A.
A port plug is supplied with the 804S. If you take it out,
you get more bass output, as shown in the room response graph below.
The off-axis response of the 804S is very good, as shown
below. There is some attenuation below 40 Hz and above 1 kHz.
For the HTM3S, the off-axis response is also very good. Note
that the bass does not fall off as it did with the 804S.
MLS quasi-anechoic frequency response of the 804S showed a
few dips. However, this is not what happens in the room response, which is
Impedance of the 804S peaks at 28 Hz, 55 Hz, and 2.5 kHz.
The minimum impedance is at about 4 Ohms. Electrical phase stays within
about ± 600.
Well, the verdict is in. Of all the speakers made
throughout the world, for those that I have listened to, B&W remain some of
my favorites. Their powerful, yet smooth, sound reminds me of
some of my other preferred designs, namely, ribbons and ESLs. In particular,
the HTM3S is one of the best center channel speakers out there.
I would have absolutely no problem being very
satisfied with a set of 804S all around, and that terrific HTM3S as the
anchor in my home theater.
- John E. Johnson, Jr. -