Tuesday, November 25, 2008

Sennheiser HD-280 pro headphones

The HD-280 pro's are closed-ear headphones designed for professional-quality monitoring. Sennheiser claims a frequency response of 8 to 25,000 Hz (-10 dB) and up to 32 dB of noise attenuation which make them particularly useful for in noisy environments. The long coiled cable has a 3.5mm jack with a 1/4" adapter that screws on for a solid connection. The street price is about $85 (hover your mouse over the picture to do a quick price check).

For the past 2 years my HD-280 pro headphones have gotten a moderate amount of use in a studio environment and they have stood up very well, in fact they still appear brand new. The HD-280 pro's are a tight fit and that is key to their deep bass response. I own a number of different subwoofers and the HD-280 pro's bass performance exceeds them all by at least an octave. I fondly call them my "pressure cans" partly because of their tight fit but mainly because that's what bass an octave below 20 Hz feels like. I've surprised myself many times listening to recordings that I thought I knew very well only to hear (feel) bass that I didn't know was even there. I fully believe Sennheiser's claim of frequency response down to 8 Hz.

The HD-280 pro headphones do an amazing job of attenuating external environmental noise. When you put them on you feel like you are in a quiet room. Sennheiser claims "up to 32 dB of attenuation" which may be true in the ultrasonic frequency range. My tests with a function generator show these attenuations with the following signal sources:

  • pink noise -6 dB
  • white Gaussian noise -9 dB
  • 100 Hz sine -1 dB
  • 400 Hz sine -3 dB
  • 1000 Hz sine -6 dB
  • 2000 Hz sine -9 dB
  • 4000 Hz sine -12 dB
  • 5000 Hz sine -15 dB
  • 7000 Hz sine -18 dB
  • 10000 Hz sine -24 dB
  • 14000 Hz sine -30 dB
The HD-280 pro's attenuation of external noise is a function of frequency. Above 400 Hz the attenuation appears to follow a -3 dB / octave reduction curve. Bass frequencies don't have much attenuation. The signal structure of white noise has less low frequency energy than pink noise which results in -3 dB more of attenuation.

Except for the 14 kHz high frequency sine wave test these numbers are all a lot lower than 32 dB but this needs to be put into comparison. Good foam earplugs will give a 30 dB reduction. The HD-280 pro's have better external isolation than any other headphone I've tried but they aren't in the same league as foam ear plugs. That said, the dB attenuation of the HD-280 pro headphones is very significant in that it creates a lower background noise floor which allows the use of a lower volume level while also improving the audibility of weak signals.

  • very accurate sound
  • deep bass pressure
  • attenuation of environmental noise

  • tight fit
  • large and heavy
  • top band messes up hairdo
  • must be worn correctly for deep bass performance

I highly recommend the Sennheiser HD-280 pro headphones to anyone who appreciates high quality audio at a value price. Bass enthusiasts and those who appreciate a quiet background environment will be pleased.

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