有大買大的迷思

alzard · 發表於 2009-8-7 20:11

看過"有感而發"後(其實我一路有睇開那條thread)﹐提起我對"有大買大"內的單元大小VS速度的興趣﹐所以就上網search一下看看有甚麼發現。

小弟都係好典型的AV初學者﹐"有大買大"已經聽過好多次﹐而前前後後都換了好幾個subwoofer。另一方面聽過sales講話買細反應快D﹐唔駛買咁大而買了有個8"的subwoofer回家﹐最後買買賣賣換返12"。

經過親身體驗過後﹐我都覺得同牌子同系列的話買大無壞﹐當然首要條件係:
1. 有錢
2. 有地方擺

簡單D講﹐subwoofer單元大小收放速度成反比﹐呢點係物理上的定律(Newton's second law - http://en.wikipedia.org/wiki/Newton's_laws_of_motion)係無可否認。而實際上分別有幾大﹐聽唔聽得出又係另一個問題﹐所以搵到少
少有趣的東東給大家參考下。

下面係一個forum內的subwoofer test結果﹐兩條curve分別係Velodyne SPL800R同
SPL1500R的Group Delay。Delay愈小﹐低音愈清/爽﹐反之會矇/慢。

結果係兩個subwoofer power一樣的情況下, SPL800R慢過SPL1500R少少。可能唔同牌子會有唔同結果﹐又或者分別唔係我地所想咁大。

800R Test: http://www.avtalk.co.uk/showthread.php?t=12075
1500R Test: http://www.avtalk.co.uk/showthread.php?t=18485
SPL-R Spec: http://www.velodyne.com/products/specs/SPL-R.html

syau · 發表於 2009-8-7 20:21

不過 sub 仔地方細用太大會唔會食唔起？

alzard · 發表於 2009-8-7 20:44

不過 sub 仔地方細用太大會唔會食唔起？
syau 發表於 2009-8-7 20:21

上網搵過好多resource但係無定案﹐所以唔知點答。

starball · 發表於 2009-8-7 20:47

岩岩學識四字詞語(一步到位)

孤身走我路 · 發表於 2009-8-7 21:15

岩岩學識四字詞語(一步到位)
starball 發表於 2009-8-7 20:47

唔..........................冇錯 ! 就係一步到位 !

alzard · 發表於 2009-8-7 21:24

The magnet and voice coil structure of the SPL800 and SPL1500 are totally different story. Look at the spec.

SPL800

Magnet Structure: 204 oz. (12.7 lbs)
Voice Coil: 2.5" inside/outside

SPL1500 ...
ryanenen 發表於 2009-8-7 21:11

True, the larger size of magnet structure may be used to compensate the inertial difference between the cones. I think the manufacturer already taken into account in their product design between different model of their subwoofers.

alzard · 發表於 2009-8-7 21:26

That's why the 單元大小VS速度 is not only depend on woofer size.

Velodyne HGS18 Group delay is far better than the above subwoofers with smaller woofer size. It also depends on its design and ampli ...
ryanenen 發表於 2009-8-7 21:03

Yes, that's why I am quoting only SPL800R and 1500R because they are using AMPs with the same specification.

HGS18 should be a completely different design and AMP power which may lead to an endless argument between "egg first or chick first".