• Registered: 2017-08-26
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Topic: Normal or Hi Power for Audeze LCD-5

I did some initial testing this weekend with my ADI-2 Pro FS R BE and was able to use the normal power mode to power my LCD-5 to comfortable listening levels while working, but if I recall, I was in the -15 to -8 range on the headphone output. Not super close to 0dB, but getting there...then I noticed that the level control goes higher than 0dB.

I experimented a little with hi power vs. normal and decided to go with normal mode but I won't be able to test again for a few more days. Generally speaking, they seemed to require a little more gain than the LCD-X or LCD-4z did to reach the same listening levels, but I'm not quite sure that it means going over to hi power mode.

I know that using my ears and trial and error is best but from a purely technical standpoint, working with material that is being mastered (so anywhere from -14 LUFS to -7 LUFS on average), would one suggest using the normal mode, or hi power mode?

Here are the headphone specifications:

Transducer size - 90 mm
Maximum SPL - >130dB
Frequency response - 5Hz - 50kHz
THD - <0.1% @ 100 dB SPL
Sensitivity - 90 dB/1mW (at Drum Reference Point)
Impedance - 14 ohms
Max power handling - 5W RMS
Min recommended power - > 100mW
Recommended power level - >500mW

2 Reply by KaiS (edited by KaiS 2022-02-09 21:07:53)

  • KaiS
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Re: Normal or Hi Power for Audeze LCD-5

Hi Power doesn’t change the headphones amp in any way, same sound and dynamic range, Low- or Hi-Power.
Low Power does NOT limit the HP-Amp‘s power, it‘s still capable to deliver full power if needed, e.g. to eliminate driver's back EMF, or to drive very low impedance loads.

It‘s just the gain stage between DAC and Power Amp that’s changed by 15 dB, to make best use of the DAC‘s dynamic range.
Same mechanism like Auto Reference Level for the Line Output.

In fact the terms Lo- and Hi-Power aren‘t technically quite correct, it should be Low- and Hi-Gain.


Switch on Auto Reference Level and ADI-2 cares for the optimum setting for all kinds of music and mood.

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  • Registered: 2017-08-26
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Re: Normal or Hi Power for Audeze LCD-5

KaiS wrote:

Hi Power doesn’t change the headphones amp in any way, same sound and dynamic range, Low- or Hi-Power.
Low Power does NOT limit the HP-Amp‘s power, it‘s still capable to deliver full power if needed, e.g. to eliminate driver's back EMF, or to drive very low impedance loads.

It‘s just the gain stage between DAC and Power Amp that’s changed by 15 dB, to make best use of the DAC‘s dynamic range.
Same mechanism like Auto Reference Level for the Line Output.

In fact the terms Lo- and Hi-Power aren‘t technically quite correct, it should be Low- and Hi-Gain.


Switch on Auto Reference Level and ADI-2 cares for the optimum setting for all kinds of music and mood.

Thanks. I'll feel it out as I get to spend more real-world time with it, I just wanted to see if there were any technical reasons to not regularly work with the gain set so close to 0dB.

4 Reply by KaiS (edited by KaiS 2022-02-09 21:36:49)

  • KaiS
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Re: Normal or Hi Power for Audeze LCD-5

Jperkins wrote:

...I just wanted to see if there were any technical reasons to not regularly work with the gain set so close to 0dB.

As long as you don’t use any DSP function that boosts the level (like Bass/Treble, PEQ) - you’re fine up to 0 dB Volume setting.

Still better with Auto Reference Level, that calculates the optimum setting for you.

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  • Registered: 2017-08-26
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Re: Normal or Hi Power for Audeze LCD-5

KaiS wrote:
Jperkins wrote:

...I just wanted to see if there were any technical reasons to not regularly work with the gain set so close to 0dB.

As long as you don’t use any DSP function that boosts the level (like Bass/Treble, PEQ) - you’re fine up to 0 dB Volume setting.

Still better with Auto Reference Level, that calculates the optimum setting for you.

Thanks. I'll try the Auto Reference Level next time I have it hooked up.

6 Reply by KaiS (edited by KaiS 2022-02-10 14:53:32)

  • KaiS
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Re: Normal or Hi Power for Audeze LCD-5

Jperkins wrote:
KaiS wrote:
Jperkins wrote:

...I just wanted to see if there were any technical reasons to not regularly work with the gain set so close to 0dB.

As long as you don’t use any DSP function that boosts the level (like Bass/Treble, PEQ) - you’re fine up to 0 dB Volume setting.

Still better with Auto Reference Level, that calculates the optimum setting for you.

Thanks. I'll try the Auto Reference Level next time I have it hooked up.

Not to force wrong expectations:

“Auto Reference Level” calculates the optimum setting of the Low-/ Hi-Power switch, no more and no less.
If you already have the best setting it won’t make any difference.

For me, in daily use, it saves me from watching the output level display to do this manually.

KaiS's Website

  • Registered: 2021-01-07
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Re: Normal or Hi Power for Audeze LCD-5

Jperkins wrote:

I know that using my ears and trial and error is best but from a purely technical standpoint

Me too. I use Audeze LCD-3 headphones plugged into the IEM socket (on ADI-2 DAC). It sounds fine to me, but my head tells me that this "shouldn't" be correct - i.e. to plug such not-sensitive headphones into the IEM low-power socket. Which is 10dB less powerful than Jperkins's situation. I tend to listen between -25dB and -5dB on the volume control.

I often wonder if, at say -5dB on volume, whether I am allowing insufficient dynamic headroom.

P.S. I leave my HD800S connected to the "phones" socket.

  • 04gto
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Re: Normal or Hi Power for Audeze LCD-5

KaiS wrote:
Jperkins wrote:
KaiS wrote:

As long as you don’t use any DSP function that boosts the level (like Bass/Treble, PEQ) - you’re fine up to 0 dB Volume setting.

Still better with Auto Reference Level, that calculates the optimum setting for you.

Thanks. I'll try the Auto Reference Level next time I have it hooked up.

Not to force wrong expectations:

“Auto Reference Level” calculates the optimum setting of the Low-/ Hi-Power switch, no more and no less.
If you already have the best setting it won’t make any difference.

For me, in daily use, it saves me from watching the output level display to do this manually.

This is the way.

9 Reply by KaiS (edited by KaiS 2022-02-11 11:23:23)

  • KaiS
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Re: Normal or Hi Power for Audeze LCD-5

Mark Dirac wrote:

I often wonder if, at say -5dB on volume, whether I am allowing insufficient dynamic headroom.

The concept of “dynamic headroom” is one of these typical audiophile myths that have no base in reality.
Solid State amps do work linear and with full quality up to their maximum power or voltage.

ADI-2’s analog headphones amp stage offers an extra headroom or 1 dB above the DA-conversion’s 0 dBFS, so every value up to 0 dBr Volume (with Auto Reference Level on) is handled perfectly clean.

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  • Registered: 2018-09-12
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Re: Normal or Hi Power for Audeze LCD-5

KaiS wrote:

Solid State amps do work linear and with full quality up to their maximum power or voltage.

I'd appreciate some additional information on this.
According to the manual "high power" has more power and more voltage (1,7V vs 10V with high impedance headphones).
See 31.9 Extreme Power charts.
So when I read the manual, with my limited tech knowledge, I get the impression "high power" has more power?

11 Reply by KaiS (edited by KaiS 2022-02-11 15:52:33)

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Re: Normal or Hi Power for Audeze LCD-5

entertainme wrote:
KaiS wrote:

Solid State amps do work linear and with full quality up to their maximum power or voltage.

I'd appreciate some additional information on this.
According to the manual "high power" has more power and more voltage (1,7V vs 10V with high impedance headphones).
See 31.9 Extreme Power charts.
So when I read the manual, with my limited tech knowledge, I get the impression "high power" has more power?

The analog headphones power amp itself doesn‘t change when switching Hi- / Lo- Power.

On Lo-Power the DAC‘s maximum output level is reduced, so it doesn‘t drive the analog headphone amp to full VOLTAGE (not POWER!).

Look at the upper charts of DAC and Pro:
slightly below the 8 Ohms impedance ALL power graphs meet, because the VOLTAGE is high enough to produce full power, even on “Lo-Power”.
This wouldn’t be the case if the headphones power amp stage was altered in any way.
This is why I say the names Hi- and Lo-Power are a bit misleading, should be Hi- and Low-Gain.

Of course higher voltage capability leads to more power capability for middle and high impedance headphones.
But higher gain means more noise, so only use it when it’s really needed.


The block diagram looks like this:

[DAC chip] —> [switched Gain stage Hi = 0 dB, Low = -15 dB] —> [headphones power amp]


The advantage of this approach is:

In low power mode you can drive the DAC Chip hotter, and make better use of it’s Signal to Noise Ratio.
The headphones power amp has a very much higher Signal to Noise Ratio than the DAC, so it does not need to be switched.

Only when high Voltage is needed for insensitive headphones to play loud, Auto Reference Level switches to Hi-Power, always takes care to keep the signal clean while producing the recommended Output.

KaiS's Website

  • Registered: 2018-09-12
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Re: Normal or Hi Power for Audeze LCD-5

Sorry but I still can't follow, "high power" also has more mW (power) into headphones with an impedance of 8 Ohm or higher. According to the reference charts in chapter 31.9.
So "low power" has less mW and less V than "high power".

My ADI 2 DAC FS with auto ref level "on" seems to switch from "low" to "high" at -20db regardless of the sensitivity of the headphones. I don't have an dt880 600 Ohm at hand so I can't test it with music running and I don't want to push the HD650 that hard. -20db on the volume is VERY loud. I've turned up the volume with a HD650 or a Austrian Audio Hix65 plugged in, without music playing becuse I don't want to risk damaging the drivers.

In theory 1.7V is hardly enough to drive an HD650 (7V for 120db) and not at all suited to drive a dt800/600 (15V for 120db).
120db headroom, not volume of course.

My level of audiotech expertise is very low so I hope I don't have things uttlerly wring, I try to learn and understand.

13 Reply by KaiS (edited by KaiS 2022-02-11 16:25:42)

  • KaiS
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Re: Normal or Hi Power for Audeze LCD-5

My main point is:
There is no need or sound advantage manually switching to Hi-Power if you don’t need the power.
The opposite is true.

entertainme wrote:

Sorry but I still can't follow, "high power" also has more mW (power) into headphones with an impedance of 8 Ohm or higher.

Read again, I wrote “below 8 Ohm” the curves meet (extrapolated a few millimeters).

entertainme wrote:


My ADI 2 DAC FS with auto ref level "on" seems to switch from "low" to "high" at -20db regardless of the sensitivity of the headphones.
...
-20db on the volume is VERY loud. I've turned up the volume with a HD650 or a Austrian Audio Hix65 plugged in, without music playing becuse I don't want to risk damaging the drivers.

ADI-2 Pro switches at -15 dBr with no DSP function active, and adapts if you use, e.g. the EQ or other gain changing functions.

The switching is not dependent on what headphones you plugged in, or if the music is playing or not.

Auto Reference Level’s switching optimize the SNR between DAC and the headphones power amp.
Only if you dial more Volume than Lo-Power can supply, you’ll get more, ->Hi-Power.

entertainme wrote:

In theory 1.7V is hardly enough to drive an HD650 (7V for 120db) and not at all suited to drive a dt800/600 (15V for 120db)

As you hear, practically it is!

Just rely on what RME has thought out for you.
You won’t need to understand a car in every detail to drive it.

KaiS's Website

14 Reply by Jperkins (edited by Jperkins 2022-02-11 16:59:36)

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Re: Normal or Hi Power for Audeze LCD-5

Thanks for all the info. I am going to leave it in low power mode since I can listen comfortably without the gain getting too close to or reaching 0dB.

  • KaiS
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Re: Normal or Hi Power for Audeze LCD-5

Jperkins wrote:

Thanks for all the info. I am going to leave it in low power mode since I can listen comfortably without the gain getting too close to or reaching 0dB.

Then keep an eye on the PostFX meters.

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