Kemper Headphones Output vs Interface Heaphone Output

It does seem to be the consensus that the KPA headphone out is generally better than most interfaces used by "regular" users.

Barring any colouring of the headphone out of the KPA, then maybe it could be considered sending the DAW playback via the aux in on the kemper so you can monitor via kemper rather than the interface's headphone out (addressing your point 3) above). Don't know if the aux in is suitable for line level, though.

Its like on a Mixing Desk, the most important Part is the Preamp,

the Preamp on the KPA for the Headphones is simply a quality Part,

most other Vendors use cheap amps for HP out thats why they sound bad.

In my Opinion the Analog outs on there KPA carry the same Sound Quality

as the HP out, for me they sound better than SPDIF out

the Headphone out can't make Sound quality better, it can only deliver what it gets,

try it with a well produced track you know play it thru all you outs then you will have a ground

to decide what's best

The problem is, that in reality, the headphones output of the Kemper Profiler (33 Ohms) is quite bad. Its output impedance is way too high for a near linear frequency response (read below). The Focusrite headphones outputs (10 Ohms) are already quite a bit better in this regard. And my RME UFX+ headphones output (2 Ohms) is the best among the mentioned headphone outputs by far.

Just to give you guys yet another example of a high end headphones output … look at the highly praised RME ADI-2 Pro. Its headphone output has an impedance of only 0.2 Ohms!

Now, why does the Kemper Headphones Output seem to be better? First of all, it can drive even high impedance headphones pretty loud. The Focusrite interfaces lack in this regard while e.g. the RME UFX+ can go pretty loud as well, even with high impedance headphones.

But the most important thing happening with the Kemper Headphones Output is the very audible boost in the frequency range that is most important for guitar players. The 200Hz - 5kHz region gets a significant bump that leads to the impression that it sounds "clearer" or more "open" while the actual rig might not be that "clear" and "open" at all. This bump can be +6dB or more!

The best advice I can give on this subject is not to trust the Profiler's headphones output, at least much less than you might want to.

Cheers

Martin

but when i listen to track via aux in to HP out

i can't hear the bumps you mentioned ??

sound pretty flat

how come

I don't have the tools to do this, but it'd be helpful to see a frequency response curve of the Kemper HP out overlaid on a response of an audio interface HP out to qualify things.

just plug a track in the aux of your Kemper and listen to it

when it sound like you know it all is fine

we don't have to be to analytical here

the ear judges

Person 'A' hears a difference. Person 'B' doesn't. Would be nice to know for certain if the KPA headphone circuit is unique, other than using good quality components.

Quote from lightbox

The best advice I can give on this subject is not to trust the Profiler's headphones output, at least much less than you might want to.

but it sounds sooo good

Quote from don1960lp

it'd be helpful to see a frequency response curve of the Kemper HP out overlaid on a response of an audio interface HP out to qualify things

Here we go. Keep in mind though that even though my measurement shows the tendency I had previously described but it's not a 100% accurate measurement under scientific conditions. Also please note that the headphones I used were 250 Ohms, so the negative effect of the higher impedance output of the Profiler is less obvious. It might be more obvious with the 80 Ohms or even the 32 Ohms models.

I also want to mention that spikes and valleys in the range of 3.8kHz up can be caused by standing waves inside the closed system. The horizontal size of the closed system of both cans slightly pressed together is exactly 9cm which equals the frequency of 3.8kHz.

Anyway, it should give you a good enough indication of the level bump between 250Hz - 3500Hz

1) It s due to the AD/DA convertions:

When you listen a sound from the kpa's headphone, it s the kpa who makes the AD (guitar input) DA (headphone output).

When you re using the spdif with your soundcard and that you listen the sound from the soundcard 's headphone, it s the kpa who makes the AD (guitar input), sends this sound via spdif and then, your soundcard makes the DA (headphone output).

When you re using xlr with your soundcard and that you listen the sound from the soundcard 's headphone, it s the kpa who makes the AD (guitar input), then the DA to send this sound via xlr and then, your soundcard makes the AD (input) and at last the DA (headphone output).

The kemper's AD/DA are almost better than the AD/DA of our littles soundcards.

2) if you re using spdif, the sound recorded is the same that in the kpa, even if you listen something différent via your soundcard (due to his DA convertion). To prove it, record something via spdif, listen the sound through your soundcard. Then reamp it with everything off in the kpa and listen it via the kpa's headphone.

So there's no way?

I'm using RME Babyface Pro with RME ADI-2 PRO. Kemper is connected with Babyface Pro via analog cables.

When I record or even monitor the sound from Kemper there's no problem at all. But the problem is when I'd like to monitor via headphone out from ADI-2 Pro. The tone is totally different and lacks some vibe......

What should I do to get 'the right sound' from my headphone to capture all the sound from my DAW as well as Kemper?

Quote from lightbox

Here we go. Keep in mind though that even though my measurement shows the tendency I had previously described but it's not a 100% accurate measurement under scientific conditions. Also please note that the headphones I used were 250 Ohms, so the negative effect of the higher impedance output of the Profiler is less obvious. It might be more obvious with the 80 Ohms or even the 32 Ohms models.

I also want to mention that spikes and valleys in the range of 3.8kHz up can be caused by standing waves inside the closed system. The horizontal size of the closed system of both cans slightly pressed together is exactly 9cm which equals the frequency of 3.8kHz.

Anyway, it should give you a good enough indication of the level bump between 250Hz - 3500Hz

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The KPA plot appears to be around 2db louder across most of the frequency range. Perhaps a better way to think of that would be that the KPa output is very similar and possislightly less peaky higher up (which may not be true as you pointed out).

However, if you bring the pluts down to be in line it turns into a significant cut in frequcies below 250hz and a bit of a bump around 300hz.

Quote from SRKwon

What should I do to get 'the right sound' from my headphone to capture all the sound from my DAW as well as Kemper?

Trust the ADI-2 Pro more than the Kemper's headphones output. Monitor the Profiler through the ADI-2 Pro to setup/adjust your sounds, to record and to listen to your recordings.

I think, no matter what the actual cause of the difference is, you should make sure you use the same signal/monitoring chain for the entire process. Only this will give you consistent results.

PS: All I've written on this topic requires you/us to have ruled out all other possible differences like "Space vs. no Space", "Stereo monitoring vs. Mono recording", "Differences in monitoring level", etc.

Thanks lightbox for your quick reply, but here's the thing.

Firstly, of course I ruled out all possible output setting mistakes.

The problem is I have no problem with the following setups, except for headphone out from my ADI-2 PRO.

1. Kemper -> Babyface Pro -> ADI2 PRO -> Speaker Out

2. Kemper -> Babyface Pro -> Cubase recording -> ADI2 PRO -> Speaker Out

Only headphone out from ADI2 PRO gives me a weird lifeless sound.

Since I seem to be in analyzing mood, I measured yet another graph to compare the outputs directly. Directly means, I sent the frequency sweep to the following outputs and went by cable directly into the measuring return input. No mic, no phones involved. I matched the output levels the best I could (<0.2dB difference).

RME UFX+ Headphones Out

KPA Main Out

KPA Phones Out

As you can see, KPA Main Out and KPA Phones Out behave exactly the same. The KPA exposed a slight High- and Low-Cut compared to the RME UFX+. So I think we're safe to assume that there's no difference between the KPA outputs. The perceived difference must have another cause. One of the differences I tried to visualize before is the very different output impedance that matters when it comes to the interaction with headphones. Other potential reasons I listed in the PS of my prior post.

Quote from SRKwon

Only headphone out from ADI2 PRO gives me a weird lifeless sound.

Sadly I can't tell you what causes this impression. I don't know which headphones you use, I don't have a RME ADI-2 Pro here and I don't know your settings in the ADI-2 Pro (5-Band EQ, Bass, Treble, Loudness) and if you're using Phones output 3/4 to have a completely independent setup for your headphones. So bottomline: I can't analyze your situation, sorry