|
|
被你引来引去的文章，看人家的结论：7 ~. k2 F% v' T! l2 K4 h& J
Obviously, the cable is just a pair of wires below the transition frequency, and your speaker cables (regardless of claims or cost) are exactly the same. In case you may want to simulate this effect yourself, I used DCR=1Ω, L=200nH and C=100pF per metre, and used a 100 metre line. A shorter line does exactly the same thing, but the frequency where it becomes a transmission line (rather than a couple of wires) increases as the line length is reduced. For a 10 metre cable, the frequency is 1Mhz, and for 3 metres this increases further to 3.3MHz. These effects were present in all the previous simulations, but were masked by the amplifier's rolloff.
% D) E* q3 }- @- p- d+ a4 g% @+ R; K) l7 b4 G
不管是同轴电缆还是你的音箱线，即便是以他用来计算的放得很大的模拟参数DCR=1Ω, L=200nH and C=100pF per metre，10米的线在1Mhz的频率以下都可以认为是理想传输线，3米的极限是3.3Mhz。) @% V3 P6 L. ?, `. o0 U. p5 z
: M$ q( [8 p; _/ X& E2 X: w: [
7 n' ]/ {9 F# n' n- @4 d
It is worth noting that none of these cables is 1dB down on midband level at any frequency up to 20kHz, and even the Figure-8 lead is only 1dB down at 50kHz - it is a rare tweeter indeed that will be anywhere near as good, regardless of price4 r9 k' I; z' c, L! G
$ @3 O* p# _. Z3 M
即便是五金店卖的8号线，在50khz也不过是1db的衰减。
- M: R3 ~! n: w: Q% h6 \3 ` t! s* b注意了，人家比的是图21里红绿线的差值。: P- l, j7 H l3 H9 [! L
- W Q( s$ S! E- B! w& `
, and the Goertz cable will set you back about US$200 a pair for 4 metre lengths (and maybe make your amplifier oscillate). Naturally, you can spend a great deal more (and still make the amp oscillate), but I don't see much point.
" H: ~6 V; j8 R& [2 E: I, C& p* k2 Y- ?% }2 c
由于它过大的电容，200美刀一对的好线可能会引起放大器反馈振荡（应该是这意思吧），尽管它在超出20k以上的频段取得了很好的频响拟合，但作者还是看不出它可取之处。 |
|
IP卡
狗仔卡
发表于 2010-1-15 14:28
显身卡
