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Skeptico Saloon: An Objectivist Joint - Page 29

post #421 of 820
And are the same differences in sound heard with easy to drive headphones? Meaning it's likely a characteristic sound of the amps themselves, and not necessarily because one is driven by the speaker amp, and the other isn't.
post #422 of 820
Quote:
Originally Posted by xnor View Post
 

A better comparison would be actually measuring the volume to be equal and switching back and forth between the amps.

 

Well the next questions would be why do they sound different (or sound at all) and how (technically).

 

Of course, though I don't have the equipment to do that. I wish I did, it would make doing proper comparisons much easier.

 

The two amps I was testing were the Matrix M-Stage and the Emotiva XPA-200. The XPA-200 has more bass, deeper bass (perhaps a misinterpretation from or a result of the increased bass response), and highs that I can listen to for longer at louder volumes (less emphasized). I noticed the M-Stage had treble that was slightly uncomfortable to listen to after moderate periods of time, and my first impulse was to turn down the volume. This is interesting because if you ask most people, the M-Stage is the one with reduced highs and increased bass response, while the Emotiva is a "bright" amp. I frequently listened to a song I use to test equipment, The Bridgeport Run by The Flashbulb. It's excellent for testing specific aspects of a headphone such as transient response and detail. I noticed a more exaggerated (whether it was technically accurate I can't say, since it's electronic music) dynamic range as well as faster transient response (leading to the "punchy" type sound). I also was able to better distinguish the individual noises in the song, it's a very difficult song for most headphones to reproduce because it's just a ton of varied noises on top of each other with wild swings in volume and duration, which usually end up blending together in gear that doesn't have the ability to properly reproduce it. Essentially, it sounded "clearer", and the noises did not blend together as much with the XPA-200.

 

As for why, because I don't have the equipment to do proper measurements and official measurements can be scarce and often incorrect, I don't think I have enough information to say. The only thing I am willing to say is that there is a possibility that during dynamic peaks, I am using enough power to noticeably increase distortion on the M-Stage during those peaks. This is often incorrectly interpreted as sounding "loud" and could explain why I am able to comfortably listen to the XPA-200 at a higher volume, why the M-Stage is difficult to listen to at higher volumes, and why my impulse is to lower the volume on the M-Stage and not on the XPA-200.

 

Quote:
Originally Posted by miceblue View Post

And are the same differences in sound heard with easy to drive headphones? Meaning it's likely a characteristic sound of the amps themselves, and not necessarily because one is driven by the speaker amp, and the other isn't.
 
Unfortunately, the only other headphones I have to test are the Denon D7000, which are 25 ohm and 108db/mW and I'm not willing to power them with a 150w speaker amp, sorry.
 
I will say, though, that I love the way the D7000's sound on the M-Stage.

Edited by Taowolf51 - 11/28/13 at 7:39pm
post #423 of 820
Quote:
Originally Posted by Taowolf51 View Post
 

Of course, though I don't have the equipment to do that. I wish I did, it would make doing proper comparisons much easier.

 

For level matching, a simple $10-20 DMM is enough. Or even a sound card line input (available on any recent PC motherboard), but you need to be very careful with a speaker amp, and it must have a common ground for the input and both outputs (it cannot be bridged). Also, you should preferably make the comparison blind, since you already expect the speaker amp to sound better.

post #424 of 820
Quote:
Originally Posted by miceblue View Post


Ah, mmk.
Still, I see people saying headphones "transform" when hooked up to speaker taps.

Perhaps the extra power "fus ro dah'd" their eardrums. Nice! I didn't know binaural beats were considered an auditory illusion.

Actually, speaker taps do make my headphones transform.

 

The need to spend outrageous amounts of money on amps of  dubious merit seems to magically disappear!


Edited by swspiers - 11/29/13 at 9:37am
post #425 of 820

Quote:

Originally Posted by Taowolf51 View Post

 

Unfortunately, the only other headphones I have to test are the Denon D7000, which are 25 ohm and 108db/mW and I'm not willing to power them with a 150w speaker amp, sorry.

 

What headphones do you use, LCD2? Difference in sensitivity between the LCD2 and AH-D2000 is about 7 dB.


Edited by xnor - 11/29/13 at 12:11pm
post #426 of 820
Quote:
Originally Posted by xnor View Post
 

Quote:

 

What headphones do you use, LCD2? Difference in sensitivity between the LCD2 and AH-D2000 is about 7 dB.

The difference in sensitivity between the LCD-2 and the D7000 is 18db/mW (90 vs 108). The maximum power into 60 ohms (LCD-2) would be about 20w, while into 25 ohms (D7000) it would be about 48w. Excluding the dangers of it, the volume control may be too sensitive, and the noise floor too high for a proper comparison.

post #427 of 820
Quote:
Originally Posted by Taowolf51 View Post

The difference in sensitivity between the LCD-2 and the D7000 is 18db/mW (90 vs 108). The maximum power into 60 ohms (LCD-2) would be about 20w, while into 25 ohms (D7000) it would be about 48w. Excluding the dangers of it, the volume control may be too sensitive, and the noise floor too high for a proper comparison.

Power sensitivity and voltage sensitivity are two different matters. It was the difference in the latter that xnor was quoting, and that you have to worry about in the sense of blowing up your headphones. smily_headphones1.gif
post #428 of 820
Quote:
Originally Posted by Joe Bloggs View Post


Power sensitivity and voltage sensitivity are two different matters. It was the difference in the latter that xnor was quoting, and that you have to worry about in the sense of blowing up your headphones. smily_headphones1.gif

 

That makes more sense, I thought he was talking about power sensitivity.

 

I tried plugging the D7000's into the amp, and my fears about the noise floor were right. The noise floor is very audible with the D7000, about conversational level. I don't think I could make an appropriate comparison with so much noise.

post #429 of 820

I am not comparing the specs but real measurement data, and sensitivity specified for 1 mW doesn't help here. dB SPL @ 1V is the way to go.

 

Btw, the LCD2 only needs a couple of milliwatts to produce blaring loud sound so I'm not sure why you would drive them with a power amp.

post #430 of 820
Quote:
Originally Posted by xnor View Post
 

I am not comparing the specs but real measurement data, and sensitivity specified for 1 mW doesn't help here. dB SPL @ 1V is the way to go.

 

Btw, the LCD2 only needs a couple of milliwatts to produce blaring loud sound so I'm not sure why you would drive them with a power amp.

 

Makes sense, though still, considering how loud the noise floor is with the D7000's, I'm not quite sure how much of a help or how accurate a comparison would be.

 

Honestly? Because I like the way it sounds more than the M-Stage. I really couldn't care less about anything else. It also doesn't cost me an ungodly amount of money like most other amps ($30 for the converter so far).


Edited by Taowolf51 - 11/29/13 at 7:05pm
post #431 of 820
Say you needed music to reach a peak SPL of 120 dB, the LCD-2.2 requires 0.87 mW of power at 58 Ω to reach 90 dB SPL according to Innerfidelity's measurements.

A +3 dB SPL gain equates to doubling the required power.

To reach 120 dB SPL, you double the power 10 times.
120 dB SPL - 90 dB SPL = 30 dB SPL
30 dB SPL / 3 dB SPL/double of power = 10 doubles of power

0.87 mW * 2^10 = 890.88 mW at 58 Ω


How about 115 dB SPL?
115 dB SPL - 90 dB SPL = 25 dB SPL
25 dB SPL / 3 dB SPL/double of power = 8.333 doubles of power

0.87 * 2^8.333 = 280.61 mW at 58 Ω
post #432 of 820
Quote:
Originally Posted by miceblue View Post

Say you needed music to reach a peak SPL of 120 dB, the LCD-2.2 requires 0.87 mW of power at 58 Ω to reach 90 dB SPL according to Innerfidelity's measurements.

A +3 dB SPL gain equates to doubling the required power.

To reach 120 dB SPL, you double the power 10 times.
120 dB SPL - 90 dB SPL = 30 dB SPL
30 dB SPL / 3 dB SPL/double of power = 10 doubles of power

0.87 mW * 2^10 = 890.88 mW at 58 Ω


How about 115 dB SPL?
115 dB SPL - 90 dB SPL = 25 dB SPL
25 dB SPL / 3 dB SPL/double of power = 8.333 doubles of power

0.87 * 2^8.333 = 280.61 mW at 58 Ω

 

I know.

post #433 of 820

Anyone heard the new Schiit Vali yet? Impressions?

post #434 of 820
Quote:
Originally Posted by ssrock64 View Post

Anyone heard the new Schiit Vali yet? Impressions?
Someone, or two, might bring one to the next local Head-Fi meet. I'm skeptical, but I've got the Objective 2 at hand for comparisons.
post #435 of 820
Quote:
Originally Posted by miceblue View Post


Someone, or two, might bring one to the next local Head-Fi meet. I'm skeptical, but I've got the Objective 2 at hand for comparisons.

That's precisely the comparison I want to hear; I'll hold you to that duty if you get the chance.

 

I've heard all the hype, but all the talk of microphonics and hiss is quite concerning.

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