Subject: hd414 "classic" headphones From: Bob Carlyon <bob.carlyon(at)MRC-APU.CAM.AC.UK> Date: Fri, 22 Dec 1995 12:31:24 +0000Some of you may recall brian moore's message informing us that sennheiser have re-introduced the hd414 headphone for a limited period. I was so excited that I bought a bunch. We have now calibrated 5 headsets (10 earpieces), and thought that some of you might be interested in the results. The headphones meet all the manufacturer's specifications, but the distortion is considerably higher than that on several "old" pairs of 414s . The range across headsets of second and third harmonic distortion re a 1V primary (with that seen on one old headset in parentheses), was as follows: (* = not measurable) 2nd harmonic 3rd harmonic Freq Atten re primary Atten re primary 250: 38-47 (66) 33-65 (73) 500: 48-55 (68) 49-73 (69) 1000: 55-60 (72) 67-* (*) 2000: 52-67 (78) * (*) 4000: 33-63 (71) 60-* (*) 8000: 65-49 (70) 73-* (*) Measurements were made using a B&K 4153 artificial ear and a B&K 0.5 inch condenser microphone, model no 4134. Analysis was performed with the aid of an HP3562A spectrum analyser, Jay Datta, Christian Lorenzi, and Minoru Tsusaki. And merry christmas to you too. Bob ------------------------------------------------------------------------------ Bob Carlyon MRC Apllied Psychology Unit 15 Chaucer Rd. CAMBRIDGE CB2 2EF England Phone: (44) 1223 355294 ext 720 FAX: (44) 1223 359062 email: bob.carlyon(at)mrc-apu.cam.ac.uk ---------------------------------------------------------------------------- --