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Converting Kef 104/2 to biwire/amp

 
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we5004
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Joined: 01 Mar 2014
Posts: 8

PostPosted: Fri Apr 11, 2014 4:03 pm    Post subject: Converting Kef 104/2 to biwire/amp Reply with quote

I have a pair of single wired Kef 104/2s and have added a second pair of SP2050 crossovers. I have used 5.6 ohm 50 watt wirewound resistors to provide dummy loads where appropriate on both crossovers. I am using two Arcam Alpha 10 amplifiers but am surprised to hear that, whilst a degree of presence and air have been achieved, the tweeters are too bright to be comfortable. Can anyone explain why this might be the case please, and the best way to evercome? Many thanks. Peter
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audiolabtower
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Joined: 06 Jan 2009
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PostPosted: Fri Apr 11, 2014 7:24 pm    Post subject: Reply with quote

Do I understand your post properly? You are trying to bi wire/bi amp a single pair of 104/2s by using 2 sets of crossovers on 2 stereo amps with the relevant non-used drive units replaced by resistors to load the crossovers?

It will not work because the drive units are a combination of inductance and resistance mainly and thus the frequency balance will be altered from original design by the removal of the drive unit inductance?

The way to do it is to separate the bass and treble circuits of a single crossover in each speaker by cutting tracks on the printed circuit board and running 4 cables from each speaker back to each stereo amp. I would suggest using each stereo amp for each channel in a pseudo monoblock arrangement - left channel stereo amp for left channel speaker (amp left for speaker treble, amp right for speaker bass). Ditto for other speaker and stereo amp.

Good luck! I have a similar arrangement on my 105s with 3 power amps and feel it is really worthwhile upgrade equivalent to a much more expensive hi-end single amp.

By the way this the music forum so maybe a mod can move the thread to the Speakers forum?
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we5004
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Joined: 01 Mar 2014
Posts: 8

PostPosted: Fri Apr 11, 2014 7:33 pm    Post subject: Reply with quote

Thank you very much for your reply. I guess you are referring to biamping vertically rather than horizontally. I will try what you are suggesting. The other option I suppose is to wait until I can get a crossover from an old pair of biwireable 104/2s. I did have a pair of 105/3s but couldn't afford sufficient amplification at the time, so sold them. What an idiot!
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