Can E9 drive LCD2 well - Page 3

Quote:

Originally Posted by SanjiWatsuki 

Most computer outputs have around 1-1.2V.

That varies, some sound cards have less than 1V, while the better (but still quite affordable) ones can output 2-3V. The output impedance varies greatly, I have measured a few Ohms as well as more than 100.

Quote:

Originally Posted by SanjiWatsuki 

To reach 110dB SPL with the LCD-2, you need closer to 9V but not everyone needs that kind of volume from their headphones.

Is that sure ? According to the measurement on InnerFidelity, the LCD-2 (rev 2) needs 0.225 Vrms for 90 dB, that translates to 2.25V for 110 dB. A few other LCD-2/LCD-3 measurements are also available there, all of which indicate better sensitivity.

Yeah, I was completely off base with the 9V and already edited that mental flop my post. I'm not sure what I was thinking when I posted that. 

I was estimating more the integrated sound cards. There are some excellent sound cards on the market in terms of output, though. And, yes, the output impedance does vary greatly on them.

Quote:

Originally Posted by stv014 

 

That varies, some sound cards have less than 1V, while the better (but still quite affordable) ones can output 2-3V. The output impedance varies greatly, I have measured a few Ohms as well as more than 100.

 

Is that sure ? According to the measurement on InnerFidelity, the LCD-2 (rev 2) needs 0.225 Vrms for 90 dB, that translates to 2.25V for 110 dB. A few other LCD-2/LCD-3 measurements are also available there, all of which indicate better sensitivity.

 

Quote:

Originally Posted by kicker 

well do they give like 80 or 85 % of it capacity? or less ? if it less then it wont make sense to me to spend 1k on this i would rather get a hooker for 1 year nonstop

You cannot quantify sound however if you are spending a lot of money on headphones it would be wise to spend $200 or so on a nice source.

There's more to amplifiers than just power. The two biggest factors are output impedance rating and distortion. The E9 has a 10 ohm output impedance, not terrible, but also not great. This means that they are ill-suited to power low-impedance dynamic headphones. A high output impedance colors the sound by normally emphasizing bass around 100hz on low impedance headphones (this all relies entirely on impedance ratings of a pair of headphones at a given frequency, there are charts of this). This can also affect how much control a source has over a dynamic driver at low frequencies, which can result in low electrical damping, but that's a whole different topic. Do note that this advice is specific for dynamic headphones.

If you're really interested in impedance ratings and their effect on sound, I made a topic on the Sound Science forum about my thoughts. 

As for distortion, it is exactly what it sounds like. Super high end amplifiers should have a lower amount of distortion. Personally, I think the Fiio E9 probably doesn't add enough distortion to be truly audible, but to each their own.
 

Edit: To some degree, amplifiers can color the frequency response of a sound, but that's just a poorly designed amplifier. Most amplifiers beyond $50 won't do this unless they are purposefully doing it and it is advertised. 

Quote:

Originally Posted by Hzwwwc2 

So E9 has more than enough power to drive LCD2? then what is the advantage of much more expensive amplifier. I head that amp does more than drive, but I don't know what it is.
 

 

Output impedance is something that either has to be measured by someone with the equipment or published by the manufacturer. Almost no manufacturer publishes it. 

Here's a link to Fiio's own site with a republished review of the Fiio E9 with someone who measured it, though. 
 

Quote:

Originally Posted by Hzwwwc2 

Thank you so much for the detailed explanation. I'll look into your other posts on impedance rates. 

Plus, where do I look for the output impedance rating? I looked over the specs of E9 and didn't find it.Is it something to be calculated?

Well, not all amps are able to put out enough voltage for all headphones. Their published distortion specs may not always be accurate and they can fluctuate depending on listening conditions, too.  Some people also like having a DAC built into their amplifiers, such as the Fiio E7 or iBasso amps. Some amps come with special functions like bass boost which is essentially the main function of Digizoid's amps. Some prefer the "warm sound" of tube amps that can be caused by their funky impedance ratings and how it alters the frequency response (Reading up on Richard Clark's $10000 wager on tube amps is a good read). Other people buy into aspects which I find to be snake oil, such as the the difference in sound output between different op amps. 

For the most part, though, if it has enough power, low distortion, and a low output impedance, the amp is golden as far as I'm concerned. There are a few other issues like channel imbalance that can pop up, but I think for most well-designed amps that is a minor issue that is rarely a big problem.

Quote:

Originally Posted by Hzwwwc2 

So it looks like as long as desktop amp, there always will be enough power to drive them. It is all the impedance rating and distortion that matter. And since impedance rating can be tested, distortion rating is written on the product spec, can I say based on the two numbers I can decide whether it's a good amp or now. If that, why there're so many people listening to all different kinds of amp, is there something more about amp that can't be measured?

Most portable headphones have a low impedance, meaning the lower output impedance is more important for them.

The E9 is normally used to power higher impedance & more power hungry headphones that are less affected by higher output impedance. 
 

Quote:

Originally Posted by Hzwwwc2 

why E7 E5 are much better in output  impedance, while E9 is desktop amp and e5 e7 is portable amp?

Will the E7/E9 make the LCD-2 sound good. Likely.

Is it ideal? Far from it.

Honestly, $1000 headphones are more than just plug and play, they need a system to be built around them (source/dac/amp/cables, etc...).