Thuneau
New Head-Fier
- Joined
- Aug 14, 2004
- Posts
- 16
- Likes
- 2
Hi, my first post in this forum. I posted this at Headwize.com but I thought I might get a few more comments here.
I recently bought the AKG K-1000 headphones, and while these are a well known entity with many reviews on the web and in press, I haven't seen the approach I'm about to describe, so I thought I'd share.
When first listening to the K-1000 I noticed that they exhibit a rather significant IMD (intermodulation distortion) when faced with deep bass in music played at any level above average (85dB SPL or so). The overall sound becomes a bit strained and "gargly" as the distorting low frequencies modulate the midrange. I use a pretty powerful amp (200W/ch at 8 Ohm Adcom) and a tube preamp. It's not my electronics that are straining.
The low frequency extension of the K-1000 is about 50Hz with a natural 2nd order rolloff. I happened to have an older Nakamichi EC-100 crossover, which uses 2nd order electrical filters. It's a mixed opamp/transistor design with high quality ceramic NE 5532 opamps at the heart of the filters. I decided to utilize it in connection with my JBL LSR-12P studio subwoofer. The sub has a fixed 4th order Linkwitz/Reiley Low Pass filter at 80Hz. I provide a full range signal from my preamp to the sub and use the second order Nakamichi filter before the headphone amp. That filter, when dialed in (by ear) to about 70Hz results in a fourth order acoustic High Pass filter that complements the sub very nicely. The K-1000 when relieved from the low bass duties really shines. There is no strain in the music at any (sane) level. I can hear some coloration from the Nakamichi crossover, but for me the quality gains in IMD distortion far outweigh the losses due to opamps in the path. In the future I will investigate a fixed 2nd order HP, either passive or active with purist design, but for now the enjoyment is just great. The added bonus is a real bass "pressure-on-the-chest" feeling that no headphones can provide. Highly recommended path for experimentation.
I recently bought the AKG K-1000 headphones, and while these are a well known entity with many reviews on the web and in press, I haven't seen the approach I'm about to describe, so I thought I'd share.
When first listening to the K-1000 I noticed that they exhibit a rather significant IMD (intermodulation distortion) when faced with deep bass in music played at any level above average (85dB SPL or so). The overall sound becomes a bit strained and "gargly" as the distorting low frequencies modulate the midrange. I use a pretty powerful amp (200W/ch at 8 Ohm Adcom) and a tube preamp. It's not my electronics that are straining.
The low frequency extension of the K-1000 is about 50Hz with a natural 2nd order rolloff. I happened to have an older Nakamichi EC-100 crossover, which uses 2nd order electrical filters. It's a mixed opamp/transistor design with high quality ceramic NE 5532 opamps at the heart of the filters. I decided to utilize it in connection with my JBL LSR-12P studio subwoofer. The sub has a fixed 4th order Linkwitz/Reiley Low Pass filter at 80Hz. I provide a full range signal from my preamp to the sub and use the second order Nakamichi filter before the headphone amp. That filter, when dialed in (by ear) to about 70Hz results in a fourth order acoustic High Pass filter that complements the sub very nicely. The K-1000 when relieved from the low bass duties really shines. There is no strain in the music at any (sane) level. I can hear some coloration from the Nakamichi crossover, but for me the quality gains in IMD distortion far outweigh the losses due to opamps in the path. In the future I will investigate a fixed 2nd order HP, either passive or active with purist design, but for now the enjoyment is just great. The added bonus is a real bass "pressure-on-the-chest" feeling that no headphones can provide. Highly recommended path for experimentation.
