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发表于 26-8-2009 09:29 AM
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原帖由 大明明 于 25-8-2009 08:10 PM 发表 
离开新山还蛮远的，不过，我有一次从大山脚开车到新加坡（在新山住一晚）去抬回一对 Pro-Ac 3.5 那是四年前的事咯。 严格说起来，你比我们有优势呢！因为新加坡很多靓野!
哇！那你的车油都去掉多少钱了哦。。。
真的吗？？新加坡很多便宜的宝贝啊？？你是怎么样找到的?? |
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发表于 26-8-2009 12:02 PM
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原帖由 needforsleep 于 26-8-2009 12:51 AM 发表 
大明兄，你好。。。我想询问一下那de-couping rubber在哪里购买。。。那是hifi的牌子还是机器coupling的rubber。
那个 de-cloupling rubber 是在 Wisma Audio （Penang） 买的。 4片大概 RM160 （~6x6cm Per 片）。 它必须是特定的硬度,弹性...才有正面效果. 太软或太硬会有反效果. 以下是 Peter Holstein soft de-cloupling 理论全文:
"The theoretical side of soft deoupling" ( 04-09-2002 )
For many years the spike has been a regular part of improving a loudspeaker set up. Thoug now it is time to look at this from a complete new point of view:
Most of the acustical resonances we experience in the listening of music does not come from the acoustical output the loudspeaker itself, but rather from the mechanical coupling between the loudspeaker and the floor. As such the slow and boomy bass from most active subwoofers is caused by the mechanical resonances in the floor and not the "poor" quality of the subwoofer!
What happens is what we will call the "Tuning Fork Principle". When we use the tuning fork to tune an instrument, the first thing we do with it is to hit the edge of i.e. a table to make it swing. As long as we have the tuning fork between our fingers, we hardly can hear it, and as such we always place it in the resonance box to amplify the acoustical output from the tuning fork.
This is exactly what happens with a loudspeaker or a subwoofer – as long as we "hold the speaker between our fingers", we cannot hear the vibrations in the cabinet, but as soon as the cabinet couples to the floor or a shelf, the acoustical output of the mechanical resonances is dramatically increased.
When the correct soft material is used vibrations between loudspeaker cabinet and floor / shelf, then the speaker cabinet is as isolated as "hold the speaker between our fingers".
Mathematically we can illustrate the effectiveness of the decoupling as follows: (As example we use the Holfi Charisma mkII loudspeaker)
Te weight of the speaker is 35 kg each, and the moving mass of the woofer diaphrames is approx 35 g. As such, when the diaphrames move forward 1 cm, then the cabinet will move backwards 1000 times less or 0.01 mm backwards.
1000 times = 60 dB
100000 times = 100 dB
The soft decoupling feets works as a second order swinging system, that is the damping effect will increase by 12 dB / Octave or 40 dB / decade going below or beyond the system resonance frequency. Using the Holfi SB-XL-Feet with the Tyra Charisma makes a 2 Hz system resonance (or free swinging resonance frequency). At 20 Hz the SB-XL-Feet will provide 40 dB damping of the swinging system and 80 dB at 200 Hz. As the swinging is caused by the diaphrames moving, then we can add on 60 dB in the damping from the mass / moving mass relationship between cabinet and diaphrames.
In total we will have 100 dB damping at 20 Hz and 140 dB damping at 200 Hz! As such when the woofers move forward 1 cm, then the cabinet will move backwards less than 0.0001 mm!
Thereby the cabinet is defenately in a "fixed" position, yet we have no mechanical coupling between cabinet and floor. And this is why we hear the bass much more refined, clear, precise, powerfull and dynamical rather than using the spikes. Also the harsness in midrange and treble from mechanical resonances in speaker cabinet is now completely gone as we have avoided the "Tuning Fork Principle".
The Holfi decoupling feet are available in three different versions:
Holfi BV-Feet can be used for decoupling both electronic products and loudspeakers of weight less than 15 kg.
Holfi SB-Feet can be used for decoupling both electronic products and loudspeakers of weight between 15 kg and 25 kg.
Holfi SB-XL-Feet can be used for decoupling both electronic products and loudspeakers of weight plus 25 kg.
Please click the feet in the right hand menu to read more details. |
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发表于 26-8-2009 03:15 PM
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发表于 28-8-2009 02:40 AM
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回复 1167# 大明明 的帖子
又学到野。。。多谢！ |
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发表于 28-8-2009 01:57 PM
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看了过后觉得头昏眼花。。。好多毒品。。。。。。。。。。。。。
要开始存钱了。。 |
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发表于 2-9-2009 04:10 AM
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原帖由 楊小邪 于 1-9-2009 04:55 PM 发表
初哥的入門玩具
http://photos-p.friendster.com/photos/68/98/46838986/2_552416118l.jpg
http://photos-p.friendster.com/photos/68/98/46838986/2_769142446l.jpg
http://photos-p.friendster.com/photos/68/9 ...
你的树胶买多少钱,
放了有什么做用...声音变得怎样 |
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发表于 2-9-2009 11:24 AM
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原帖由 楊小邪 于 2-9-2009 10:19 AM 发表
防震咯,但我木耳听不出放和不放的分別,可能心理作用較大吧!
对咯！DIY很多时候常常都是拿个心理安慰罢了。。。哈哈！ |
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发表于 3-9-2009 03:24 AM
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发表于 3-9-2009 03:21 PM
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发表于 4-9-2009 11:53 PM
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发表于 5-9-2009 12:34 AM
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发表于 5-9-2009 12:44 AM
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原帖由 黑仔3838 于 4-9-2009 11:53 PM 发表
小弟献丑.....了！！！！
以下就是小弟我最近所更换的音响系统
...
哗！不得了，整套换过。美感一流！我本身喜欢座地喇叭，希望你会享受 full range 的乐趣！ |
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发表于 5-9-2009 02:33 AM
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回复 1185# 黑仔3838 的帖子
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劲啊。几乎都换掉。相信声音也完全是不一样的吧。升级到这么快。真是羡慕死我啦。 |
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发表于 5-9-2009 08:21 AM
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发表于 5-9-2009 03:54 PM
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发表于 5-9-2009 04:03 PM
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发表于 5-9-2009 04:08 PM
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发表于 5-9-2009 04:21 PM
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发表于 5-9-2009 05:27 PM
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发表于 5-9-2009 05:57 PM
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