As somebody else pointed out, at low frequency a flat response for a headphone sounds as if there isn't enough bass, for example pipe organ music sounds good, but doesn't sound like you are standing in the cathedral . talk ) 00 : 49, 24 June 2013 ( UTC)
32.
This is still subject to phase cancellation, but cone woofers can be driven to far higher levels due to their longer excursion, thus making equalization to a flat response easier, and they add distortion thereby increasing the area ( and therefore the power ) under the frequency response graph, making the total low frequency energy higher but the fidelity to the signal lower.
33.
However, the Kahn system suffered from lower stereo separation above 5 kHz ( reaching none at 7 kHz whereas FM stereo has 40 dB or more separation at 15 kHz ) and the radio antenna array on directional AM ( common on a lot of nighttime and some daytime stations ) had to have a flat response across the entire 20 kHz AM channel.
