这估计又会涉及：监听 VS HIFI 的讨论
eggmud 发表于 2019-8-8 10:22
典型案例：有个叫halcro的音响品牌，设计师属于物理大师，后级失真指标业内最低，驱动力很强，但不好听；它 ...
Halcro确实谈不上好听，但很明显听出来就是失真度极低的声音。听音经验丰富的烧友可以辨别出这种失真度极低的器材的声音——基本就是很白开水的声音，但非常透明和细腻。那种可以形容为“韵味丰富”的机器，失真度都不会很低。
本帖最后由 Phase 于 2019-8-8 12:38 编辑
小白 发表于 2019-8-8 12:21
Halcro确实谈不上好听，但很明显听出来就是失真度极低的声音。听音经验丰富的烧友可以辨别出这种失真度极 ...
因为这些thd失真度其实测的都是一瓦到最大功率，说白了，在实际听音中，只对应最大的那些声音信号，也就是说发布指标thd极低的机器，只是说明能把最大的声音放准确了，而音乐的细节依然可能放的很差。音乐细节一旦放的差，那么余音，韵味，微动态，音色这种东西都是出不来的。
引用一段，有个功放设计师说halcro在极小功率的测试下失真是很严重的。这也说明了halcro为什么不好听。而直热三极管的wavac在极小功率的thd远远好于halcro
MEASURING ULTRA LOW-LEVEL MUSICAL AMPLIFIER SIGNALS
This may be the most important letter I have ever received from a reader. The letter speaks for itself, and is unedited, with my bold. (My "personal comments", plus a sceptical and cautionary perspective from another source, will follow below).
"My name is Steve Keiser, the 'K' of B&K components, and presently design engineer with Luminance Audio. I have developed a measurement system which is able to quantify distortion levels at micropower quantities down to 1/1000th of a watt. These measurement techniques are unprecedented, and have revealed a number of revelations of amplifier distortion characteristics, at micropower levels, which are in direct opposition with traditional and scientific assumptions up unto this point.
The emphasis of my work is to definitively quantify low level signal linearity measurements of power amplifiers, and attempt to correlate these measurements with subjective listening results, as well as establishing the significance of low level distortion. Conventional test equipment generally does not resolve meaningful distortion measurements below 100mw, since the measurements become predominated by noise.
I have modified a spectrum analysis software program, which uses time-averaging to effectively cancel out noise products, leaving an identifiable signal and its related harmonics. This time-averaging approach is to identify extremely weak signals from spacecraft, amid a very high noise ambient background. Using this method, I am able to resolve a standardized total harmonic distortion measurement down to 1/1000 watts, and an approximate measurement down to 1/500,000th of a watt.
My measurement results oppose common engineering supposition, in that it is commonly believed that very low signal linearity is essentially 'virtually perfect', and that only high level signal linearity is a relevant parameter. My measurements indicate exactly the opposite is true of this common held assumption, particularly for amplifiers employing solid state devices.
To give you an example: the Halcro DM58 amplifier measures .007%THD at 2 watts, whereas at 1/1000th watts, THD measures 8.9%! By contrast a Wavac SH833 measures .57%THD at 2 watts and 1.6%THD at 1/1000th watts. The tube Wavac exhibits significantly lower THD at low signal levels by orders of magnitude than the Halcro. I have measured numerous amplifiers, both solid state and tube, which I will provide to you as well as any other information you may want pertaining to this work.
Phase 发表于 2019-8-8 12:36
因为这些thd失真度其实测的都是一瓦到最大功率，说白了，在实际听音中，只对应最大的那些声音信号，也就 ...
他的问题反映在主观听感上主要是小功率时、特别是小音压声音不活，听上去平板。
Phase 发表于 2019-8-8 12:36
因为这些thd失真度其实测的都是一瓦到最大功率，说白了，在实际听音中，只对应最大的那些声音信号，也就 ...
或者可以这么说，按照这段文字的意思，halcro更适合现代材质低灵敏度扬声器，而wavac胆机更适合古董号角全频等高灵敏度扬声器？
Phase 发表于 2019-8-8 12:36
因为这些thd失真度其实测的都是一瓦到最大功率，说白了，在实际听音中，只对应最大的那些声音信号，也就 ...
哈哈哈这解释了我的听感，halcro的确力大声粗，小声点就糙得很。
Phase 发表于 2019-8-8 12:36
因为这些thd失真度其实测的都是一瓦到最大功率，说白了，在实际听音中，只对应最大的那些声音信号，也就 ...
不过这玩意也不科学吧，谁会在50db左右听音乐呢应该测1/10w和1/100w
那现在又有个问题，很多喇叭在85db挺直的，到了70db还直吗？最现实的情况是70db在家里还直吗？
微动态不好很头大的，实际上家用多数时间是在听小音量。
eggmud 发表于 2019-8-8 10:22
典型案例：有个叫halcro的音响品牌，设计师属于物理大师，后级失真指标业内最低，驱动力很强，但不好听；它 ...
halcro的数据距离最强还差不少呢
很巧
stereophile测过halcro/蒂瓦雷/ahb2/宝达
自己比比就知道了什么情况了
反正烧油天天被厂家话术忽悠是常态;P
amex 发表于 2019-8-10 21:50
很巧
stereophile测过halcro/蒂瓦雷/ahb2/宝达
自己比比就知道了什么情况了
帝瓦雷只有初代机的测试，现在的220pro进步多了……参见https://stereo-magazine.com/archive/?tx_archive_pi1%5Barticle%5D=70043&tx_archive_pi1%5Baction%5D=download&tx_archive_pi1%5Bcontroller%5D=Archive&cHash=0b16d441fd00102e2f75be5814553a7f
即使是初代机测试，也跟ch l1半斤八两。
amex 发表于 2019-8-10 21:50
很巧
stereophile测过halcro/蒂瓦雷/ahb2/宝达
自己比比就知道了什么情况了
要看stereophile测的指标最好，那就数benchmark了……只不过这后级有人会拿它跟宝达，群星，金嗓子旗舰比吗？貌似只有stereophile这杂志这么比。
xy1689 发表于 2019-8-11 08:18
要看stereophile测的指标最好，那就数benchmark了……只不过这后级有人会拿它跟宝达，群星，金嗓子旗舰比 ...
不会。
但预算有限时，问就是ahb2，同价位怕不是没有能打的。
谢谢谭版的好文章！
设备的标称指标确实要具体研读和分析，才可以通过它们了解设备的真实性能。举个例子，最近对喇叭频响曲线有兴趣，发现很多品牌喇叭单元，标出来的是在障板条件下的曲线，而不是实际音箱条件的曲线，当然是很漂亮的曲线。有网友将相关喇叭与在特定声箱下的曲线作对比，确实相差很大。其实也并非这些品牌公布不切实际的数据，甚至是假数据，而是一个虚拟的数据，但仍具参考意义。问题是解释得不够清楚，一般消费者碍于经验不足，容易被误读。假如这些品牌喇叭公布两种数据，一种是障板条件下的数据，一种是实际环境下的数据（当然这要将测试条件写得很清楚，包括声箱类型，密闭、倒相、传输线等；尺寸；以及其它参数等），消费者就更容易明白。
