Product Review

B&W 804S Floor-Standing Speakers and HTM3S Center Channel Speaker

Part II

August, 2005

John E. Johnson, Jr.


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 removed.

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 more important.

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. -

Copyright 2005 Secrets of Home Theater & High Fidelity

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