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Focal Clear Review (headphone)

nhatlam96

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What is it you are trying to get to? What is concerning you?
My concern was, that a higher voltaged dac could make the sound louder.
For example, this setup here:
DAC (2V) > Amp > Headphone.
What happens when I increase the DAC voltage to 4V? Will the sound get louder?
Also does it increase the output voltage of the amplifier?
 

RayDunzl

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My concern was, that a higher voltaged dac could make the sound louder.
An increase in the input signal should increase the output signal.

Adjust the volume knob as necessary.


What happens when I increase the DAC voltage to 4V? Will the sound get louder?
Also does it increase the output voltage of the amplifier?
Yes, and yes.

Maybe.

---

Simple answer:

An amplifier multiplies the voltage it receives.

Music is a varying voltage. The output voltage of the amplifier traces the same waveshape as the input, but covering a different voltage range,.

The volume knob increases or decreases the range of the signal voltage sent to the amplification stage.

If the amp has 10dB gain, then one volt in will create 3.162 volts out (maximum). - the multiplier is 3.162

Change the input level to two volts, and you'll get 6.324 volts out (maximum) - the multiplier is still 3.162

If the amplifier has a different gain ratio, the multiplier will be different.

15dB gain = a voltage multiplier of 5.623

http://www.sengpielaudio.com/calculator-gainloss.htm
 
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solderdude

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Higher impedance lighter voice coil...then a higher impedance (all other things equal) implies better sensitivity (?)
But the DT-770 250 has less sensitivity than the 80 ohm version (?!)
Less voltage sensitivity, the same power sensitivity. The driver coil power is what brings the motor force. Higher resistance, less current at the same voltage, less SPL.
 

Joachim Herbert

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The most offensive aspect of these headphones isn't the clipping it's the fact that replacement earpads are $200 o_O
Have a look at the drop offering for the Elex. Same pad, different color, less than half the price.
 

solderdude

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My concern was, that a higher voltaged dac could make the sound louder.
For example, this setup here:
DAC (2V) > Amp > Headphone.
What happens when I increase the DAC voltage to 4V? Will the sound get louder?
Also does it increase the output voltage of the amplifier?
Yes, it will get 6dB louder. That's why there is a volume control.
The output voltage of an amp is controlled by a volume control which again is controlled by your sense of loudness.
Should you always listen to a certain loudness level then when swapping a 2V DAC for a 3V DAC for instance will make you dial the volume down.

The different volpot position, however, has a psychological effect on you.
A practical effect can be that a low listening level (volpot below 9'o clock) can mean more channel imbalance.
That's why some amps have a gain switch. To get a more usable volume adjustment range.
Then there is another effect that in some cases might cause problems.
Take the O2 for instance. In high gain mode with the volume knob turned down a higher voltage DAC will cause the input stage to clip and not sound as nice as it should be. Only a few amps have this though.
 

Helicopter

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Mine just don't want to crackle. The deep bass is awesome, and I can definitely feel and hear it. If Amir is not listening loudly, then my Clears must be working better.

I removed the HPF and increased the low shelves to +4/+3dB.

1608634722130.png


1608634776263.png


This is louder than I would ever listen.

20201222_060354.jpg


I guess if mine crackles, I'll just turn the volume down.
 
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Bob-23

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My concern was, that a higher voltaged dac could make the sound louder.
For example, this setup here:
DAC (2V) > Amp > Headphone.
What happens when I increase the DAC voltage to 4V? Will the sound get louder?
Also does it increase the output voltage of the amplifier?
The questions you ask are mostly justified, and a sign for an inquisitive mind, I'd encourage you to continue on that path - once upon a time, one of my teachers used to say: there are no dumb questions, only dumb answers.

But you may, additionally, do some further readings of your own, e.g. what NwAvGuy wrote is very informative.

For those of us who do practical experiments, many things are easier to understand, because you did it with your hands, you measured it, and you saw: If I input 2V in an amp with gain 2x, I get out 4V (that's within the limits of an amp). And, by the way, opamps themselves (in an output stage of an amp) have practically zero output impedance, but you might want to add a small resistor as a short circuit protection, so that the amp always sees a resistance (as if a headphone were plugged-in) even if it's shorted. In case, at least, the opamp itself has no short circuit protection (which tolerates longer shorts).

You could even start experimenting yourself, in order to find answers to your questions, getting a breadboard and a collection of components etc: the proof you get from doing it yourself, with your own hands and eyes, is so much more convincing...
 

Jimbob54

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My concern was, that a higher voltaged dac could make the sound louder.
For example, this setup here:
DAC (2V) > Amp > Headphone.
What happens when I increase the DAC voltage to 4V? Will the sound get louder?
Also does it increase the output voltage of the amplifier?
@RayDunzl gave you the right answer rather than any layman nonsense I would have said.

But just to check something I suspected based on your various posts in this and other thread-

You have 2 separate rigs feeding 2 different headphones with differing impedances. You're not trying to volume match the 2 headphones by calculating from DAC output V, amp multiplier and headphone impedance are you? So that you "know" the SPL out of each headphone is the same and therefore comparable ( as we would say testing DACS/ amps should be). Because I dont think that would work to anything like the degree of accuracy you would need to even begin to say the SPL of 2 separate rigs was the same
 

Jimbob54

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Have a look at the drop offering for the Elex. Same pad, different color, less than half the price.
I bought a pair of Dekoni (via Drop, but not the Drop ones you refer to) for Focal for about $40. Not swapped yet but feel not too dissimilar to the stock pads - hopefully they dont have a meaningful impact on sound . I dont think they have re-Dropped the actual Focal/ Drop pads for the Elex since first release. But I might be wrong
 

acbarn

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My dealer said it was older batches (I wasn't the only one reporting it) so hopefully they only make fixed versions now. I was going through a bunch and as soon as he changed his distributor to one that had newer batches, the first replacement didn't clip.
It’s interesting that they’ve fixed a problem that they also claimed was a “feature”. Which one is it, problem or feature?

I have to admit to being disappointed in the way they’ve handled this. I‘ve owned various Focal headphones and have been generally satisfied, but would be hesitant to invest further in their products given the less than transparent communication around this driver issue.
 

dfuller

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More like "weird design tradeoff that for some reason they found acceptable".
 

Joachim Herbert

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Hm. Once you start correcting for equal loudness it gets really complicated. These are the equal loudness contours as stated in ISO 226:2003. Please note that you need to boost a 20 Hz tone by almost 35 dB to make is appear to be as loud as a 1000 Hz tone playing at 80 dBA. Not sure if there is ANY equipment on the market that would accomplish this. But maybe I just do not understand the science behind this.

So the question seems more like "how close can you get", or "do you want that?". Is there any such content in live music? If artists put it on a CD (a record would not be able to carry the signal) what is the intention, give that close to 0 listeners would be able to experience this due to lack of playback capability? What about the room, whart about health issues.

Not intending to defend the Clear here, but what are reasonable design parameters for audio transducers, speakers and headphones alike.


1608655901938.png

By Lindosland at en.wikipedia - this image created by lindosland Dec 2005 using OpenOffice Draw., Public Domain, https://commons.wikimedia.org/w/index.php?curid=16477782
 

RayDunzl

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Regarding the ISO vs Fletcher Munson curves:

Do you really need 30dB additional gain at 20 Hz at 100 phons?

That's 31 times the unadjusted voltage.

1608656894367.png


My opinion:

The folks that make the recordings generally do a good job of balancing bass audibility vs midrange and treble audibility.

I've never seen such a large bass boost vs the rest of the range, either in a recording, or in monitoring and (long ago) recording a combo or two.

I tried matching the ISO curve once, and was not impressed with the result.

50dB 20hz boost at 60 phon midrange level?

1608657250890.png


316 times the midrange voltage? For the "same" perceived level?

That's nuts.

---

I go with the Fletcher Munson curve, and adjust for my "critical listening" level, of about 100 phon (peak), and make the power levels flat.

And don't worry about what difference might be indicated at lower SPL.

Nobody has complained.

---

Maybe I'm looking at this incorrectly, so straighten me out, if you like.

---

Spectrum of a pipe organ recording (slopes is not atypical of all recordings - flat to 1kHz, then a break downwards)

Other than that one note they wanted to show off in this piece, I don't see any ramping of voltage levels at the low frequencies:

Left channel

1608659395414.png


Right Channel

1608659611401.png
 
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Helicopter

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Regarding the ISO vs Fletcher Munson curves:

Do you really need 30dB additional gain at 20 Hz at 100 phons?

That's 31 times the unadjusted voltage.

View attachment 100953

My opinion:

The folks that make the recordings generally do a good job of balancing bass audibility vs midrange and treble audibility.

I've never seen such a large bass boost vs the rest of the range, either in a recording, or in monitoring and (long ago) recording a combo or two.

I tried matching the ISO curve once, and was not impressed with the result.

50dB 20hz boost at 60 phon midrange level?

View attachment 100958

316 times the midrange voltage? For the "same" perceived level?

That's nuts.

---

I go with the Fletcher Munson curve, and adjust for my "critical listening" level, of about 100 phon, and make the power levels flat.

And don't worry about what difference might be indicated at lower SPL.

Nobody has complained.

---

Maybe I'm looking at this incorrectly, so straighten me out, if you like.
I can't make sense of it either. My Clears sound a little bass heavy, and a little fake, and like synthesized dance/electronic music headphones with [email protected]/[email protected] low shelf boost I was using to see if I could get them to chatter. To my ears, Amir's 3dB/2dB is better. If you do want a big bass boost with PEQ, planars will work better anyway.
 

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Rottmannash

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I bought a pair of Dekoni (via Drop, but not the Drop ones you refer to) for Focal for about $40. Not swapped yet but feel not too dissimilar to the stock pads - hopefully they dont have a meaningful impact on sound . I dont think they have re-Dropped the actual Focal/ Drop pads for the Elex since first release. But I might be wrong
It was a disaster.
 
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