[raduray]

I just got a Qudelix 5K to go along with my 650S2 and am wondering, for a given sound level will there be a difference in battery life between using single ended or balanced output?

 

[Tom Brown]

I will share an opinion based on theory and speculation. It would be difficult, although not impossible, to get objective data so this is probably all you will get.

Before I opine, let's keep in mind the Q5K has the job of moving power from the battery to the headphone drivers. That is its job.

At low volume, it should be roughly the same. I don't know if the inverting amplifier is active during single ended use but I assume so.

There is the discussion of double ended halving impedance, so increasing the load on the output transistors. To match volume, power will be decreased. So, it will come down to the efficiency of the output transistors at higher levels versus lower levels. MOSFETs tend to be more efficient as they get closer to saturation, so this tends to suggest single ended being more efficient but this is going to be a really, really, tiny factor. We are deep in the weeds, here.

At higher volume, balanced will drain the battery more quickly. By delivering higher peak power, the amp will play louder before clipping (flat top sine wave).

A much, much larger factor is the PEQ settings. If you set bass boost to 4dB on AutoEQ, you will kill the battery way, way faster than if it is set on 2dB.

When I was tuning PEQ for HD58X, I found that 3dB was the max bass boost the Q5K could reasonably handle and still manage a reasonable volume. This varies with recordings. Something recorded in 1970 might do fine at high volume with 4dB of bass boost. Anything by Tool will tax the device at medium volume with no bass boost at all.

The end result of the PEQ tuning is that my Q5K is a 50 minute device when paired with HD58X. They are 50 glorious minutes, though.

With my desktop stack, I run 4dB of bass boost on the HD58X and 6dB of bass boost on Sundara. The amp is an A50s (3W of power) and it runs out of power on the Sundara when playing Tool or any bass heavy content. I'm not complaining. The A50s/Sundara produce a magnificent result that my ears cannot handle at top volume for more than a very brief period. My only point is: The Sundara could take more if it was available.

So, IMO, taste is going to play a far, far larger role in battery life than any other factor, on the same headphones.

 

[raduray]

Off the original topic, but have you tried the Qudex as a PEQ DAC with its headphone output into the A50s?

 

[Tom Brown]

Off the original topic, but have you tried the Qudex as a PEQ DAC with its headphone output into the A50s?

No. I use a PEQ on my PC.

The PC PEQ (EasyEffects) is better because it can load APO files from AutoEQ.app.

Actually, that's how I find the sound I want. I use AutoEQ to slowly home in on the sound signature I prefer. Once I have that, I transfer it manually to the Q5K.

This let's me test many dozens of profiles. It took a few evenings per headphone because I find my ears wash out after listening to the same tracks, dozens of times, at high volume. Eventually, everything kind of blends and sounds washed out. I give it a couple of days and start again.

I'm in my 50s so loud music is not really my thing. What I call loud would not satisfy my younger friends. I'm looking for maximum impact, not maximum sound pressure.

It would be really helpful if the Q5K could load an APO file. It is a sadly lacking feature, IMO.

BTW, in every case, the Q5K needs 3-6 dB less bass boost than the A50s. It just doesn't have the power. It still produces warm and amazing sound. It just isn't the wonderland produced by the A50s.

Switching back and forth, I much prefer the A50s. But, when I'm working around the house with the HD58X / Q5K / BT, I absolutely love the sound and do not wish for anything. Its absolutely brilliant.

 

[Tom Brown]

For what its worth, I like the HMS 3 curve (least aggressive of the curves) and I tone it down with -0.15 of tilt. From there, I add a small amount of bass boost (varies with the headphones) and that's about it.

 

[raduray]

No. I use a PEQ on my PC.

The PC PEQ (EasyEffects) is better because it can load APO files from AutoEQ.app.

Actually, that's how I find the sound I want. I use AutoEQ to slowly home in on the sound signature I prefer. Once I have that, I transfer it manually to the Q5K.

This let's me test many dozens of profiles. It took a few evenings per headphone because I find my ears wash out after listening to the same tracks, dozens of times, at high volume. Eventually, everything kind of blends and sounds washed out. I give it a couple of days and start again.

I'm in my 50s so loud music is not really my thing. What I call loud would not satisfy my younger friends. I'm looking for maximum impact, not maximum sound pressure.

It would be really helpful if the Q5K could load an APO file. It is a sadly lacking feature, IMO.

BTW, in every case, the Q5K needs 3-6 dB less bass boost than the A50s. It just doesn't have the power. It still produces warm and amazing sound. It just isn't the wonderland produced by the A50s.

Switching back and forth, I much prefer the A50s. But, when I'm working around the house with the HD58X / Q5K / BT, I absolutely love the sound and do not wish for anything. Its absolutely brilliant.

No. I use a PEQ on my PC.

The PC PEQ (EasyEffects) is better because it can load APO files from AutoEQ.app.

Actually, that's how I find the sound I want. I use AutoEQ to slowly home in on the sound signature I prefer. Once I have that, I transfer it manually to the Q5K.

This let's me test many dozens of profiles. It took a few evenings per headphone because I find my ears wash out after listening to the same tracks, dozens of times, at high volume. Eventually, everything kind of blends and sounds washed out. I give it a couple of days and start again.

I'm in my 50s so loud music is not really my thing. What I call loud would not satisfy my younger friends. I'm looking for maximum impact, not maximum sound pressure.

It would be really helpful if the Q5K could load an APO file. It is a sadly lacking feature, IMO.

BTW, in every case, the Q5K needs 3-6 dB less bass boost than the A50s. It just doesn't have the power. It still produces warm and amazing sound. It just isn't the wonderland produced by the A50s.

Switching back and forth, I much prefer the A50s. But, when I'm working around the house with the HD58X / Q5K / BT, I absolutely love the sound and do not wish for anything. Its absolutely brilliant.

I've never heard of AutoEQ before and just did a bit of searching. I use Oratory's profile which I loaded manually on the SoundSource PEQ on my MacBook Pro. When loading my headphone model into AutoEQ, and selecting the Oratory settings, it provides significantly more bass boost than the original Oratory levels. I see that you can adjust the individual parameters to your ears' preference, but I can do that directly in SoundSource, so it's not clear what AutoEQ does for me.