Help!

Hello out there, my first post. I'm a newbie Kemper-er - bought mine just before Christmas. It's not working out like I hoped, so perhaps I'm doing something wrong (or lots of things wrong!). Here are some problems:

1. Latency - the manual says 3.5mS. If I take my guitar signal and split it with an analogue splitter pedal, then route one split through the Kemper and then into one input of my Apogee recording interface (connected to Logic on my Mac with a USB port), and the other split directly to the other Apogee input... ...the Kemper split records about 3mS late relative to the direct-to-Apogee split. Btw, this is with EVERYTHING turned off on the Kemper (no FX, no amp, no cab etc.). I can feel this latency, even with the guitar plugged directly into the Kemper and monitoring directly out of the Kemper with headphones. It feels like the Kemper is dragging (and again, this is with everything switched off). If I go one step further and monitor using the Apogee using its direct monitoring mode, I'm probably adding another 1-2mS just due to the Apogee convertors, therefore total latency is ~5mS and this, to me, starts to be a problem. Further, I wonder about the latency when you switch on amps and cabs. There is a difference between "physical onset" when the sound starts rising from digital silence and "perceptual attack" when you notice the attack of the sound. Latency often (always??) seems to be measured using physical onset - but when I start playing the Kemper (again directly monitoring with headphones plugged into the Kemper) it constantly seems to be dragging. Perhaps point 2 below has something to do with this as well.

2. Lack of attack transient - this is particularly a problem on distorted sound profiles. It makes it very difficult to play in time accurately when you can't hear the beginnings of the notes. Real amps don't seem to cut the transient off: they "thwack" even with loads of gain. I've experimented with the "Pick" parameter: to me it just sounds digi. Why weren't the profiles done properly in the first place?

3. Middly, flat sound - the upper harmonics seem to be missing / inadequate. It's hard to describe, but it's almost like the profile has too much proximity effect and / or the bass was turned up way too much on the amp and / or... ...well, I don't know, but it doesn't sound (to me) like a real amp. Often what seems to happen is that there's a burst of upper frequency energy at the start of the sound, but it fades away very rapidly and you're left with 500Hz and below sustaining (check it out on a frequency analyser). Real amps don't seem to do this in the same way.

4. Distorted sounds aren't very good - I will I'm sure be criticised for this - it's very subjective! But is it? To me, every Kemper overdriven / distorted profile I've heard sounds somehow "digi", metallic (and middly and flat too) and just not very convincing.

Any and all input appreciated!

Thanks in advance.

Question: it possible to improve Kemper's latency performance?

And he's some data as background.

I did some tests, using a Logic Klopfgeist click recorded onto my old Roland VS2480. This, if you like, was the "Control Click". I then bounced the CC using various routings to test the latency thereof. Results obtained by really zooming in on the waveform and measuring are as follows:

1. Out of VS2480 headphone output, back into VS2480 input. Result: 1.67mS delay (this is the "inherent" delay of one loop through the VS2480, obviously including it's DAC /ADC converter cycle, which is what you get when you record and monitor with this device).

2. Out of VS2480 master output, back into VS2480 input. Result: 1.67mS delay i.e. the same as 1, above (this was just to test that there's no difference between using the headphones out and the master out of the VS2480).

The following results are all stated both "gross" i.e. the latency of the whole chain, and "adjusted" i.e. the latency of just the component under test, after deducting the VS2480's "inherent" latency.

3. Out of VS2480 master output, into Apogee Duet connected to MacBook pro and with Logic booted up @44.1kHz sample rate and 64 samples I/O buffer. Then straight back out of the Apogee's headphone out i.e. not using software monitoring. The idea here is to test how good Apogee's "direct monitoring" is. Result: 3mS delay. Adjusting for the VS2480's 1.67mS inherent delay, this means Apogee - even in direct monitoring mode - is adding another ~1.3mS of latency.

4. Out of VS2480 master output, into 1998 POD on "POD Clean" patch. Result: 3.3mS delay (~1.6mS adjusted).

5. As for 4. but using a different POD patch: this time the "Brit Hi Gain" patch. Result: identical to 5. above, so it seems POD patch has little effect on latency.

6. Out of VS2480 master output, into Kemper with Stomps, Stack and FX all disabled. Result: 4.3mS latency (~2.6mS adjusted).

7. Out of VS2480 master output, into Kemper on "AC30 Clean SM57" patch (I think the 3rd patch that comes up on the factory default list). Result: 5mS latency (~3.3mS adjusted).

8. As for 7. above, but using AS Mars MP Gain 8 patch. Results: identical to 7. above.

So what?

Well, first, this means that in a "real world" recording scanario (recording using Kemper into an Apogee Duet using Apogee's "direct monitoring") total latency is ~3.3mS for Kemper (the manual I think says 3.5mS) plus a further ~1.3mS of latency for the Apogee Duet's "direct monitoring" i.e. a total of 4.9mS.

Latency seems to be a bit like having a drink. You don't notice the first one, or even the second. But after a few drinks you definitely notice the cumulative effect.

4.9mS is right on the cusp of when no less an authority than Yamaha say "playing starts to become difficult" due to latency (i.e. hearing what you're playing fractionally late verses your actual playing). Here's a link to that Yamaha article:

http://www.yamahaproaudio.com/…ter5/05_absolute_latency/

and, in summary, this is what it says.

signal path latency for in-ear monitor systems

1.15 - 2 ms Playable without any big problem.

2 - 5 ms Playable, however tone colour is changed.

5 - 10 ms Playing starts to become difficult. Latency is noticeable.

>10 ms Impossible to play, the delay is too obvious.

So, in summary, with a real world recording chain, the latency of playing using Kemper is such that "playing becomes difficult". This is my experience.

Back to my original question: is there any way of improving Kemper latency? I ask because my 20 year old POD has about HALF the latency of Kemper (~1.6mS vs ~3.3mS). And POD plus Apogee Duet comes in at ~2.9mS which is less than listening to Kemper with headphones plugged directly into Kemper.

To those that say "but 5mS of latency is like standing 5 feet away from a real amp / cab" I say: take a simple midi drum loop and shift e.g. the Kick backwards (or forwards) 5mS and then then try playing along to it. Or leave the Kick and instead move the Snare by 5mS. Or leave the entire loop as is, but add a click track mis-aligned by 5mS and try playing along listening to both. Then repeat the whole thing using 10mS instead of 5mS to see what Yamaha mean.

To me, Kemper drags. It just does. And I think latency is part of, but not, the problem. But it would be nice at least to try to improve the latency bit.

Thx!

I hear this latency "1 foot=1mS and think about what it's like standing 20 feet from a cab" all the time. It's not my experience. Depending on what type of sound one is aiming for, a lot of the time when recording one is monitoring through headphones. And it's disconcerting when you hear the sound even fractionally after you've actually played. And - yes in my experience - a few milliseconds makes all the difference. What I usually end up doing is uncovering one ear, listen to the backing track quietly through one headphone can and listen to my (electric) guitar playing acoustically. This sounds natural and means I play reasonably well in time. Listening ONLY to what comes through the cans from the Kemper (whether plugged direct into the Kemper headphones and guitar, or using direct monitoring with an audio interface) sounds - to me - lagging and un-natural and timing deteriorates dramatically. Those that don't hear this - well, you're blessed and good luck to you all! I'm an not a virtuoso musician - I'm 54 years old and I didn't start playing the guitar until I was 14. But I played the piano and did all the grades from age 6 - and latency matters. Playing is either tight and in time - or it's not. The issue - it seems to me - with Kemper is that the processing + a round of ADC / DAC gets you to that 3.5mS latency they quote in the manual; add another round of ADC / DAC if - like me - you're using an audio interface (in my case an Apogee) and you're up to 5mS of cumulative latency. Most independent academic studies say that >=5mS of latency starts to affect playing - and this is certainly my experience. The only solution I can see is like you do with guitar sim. plug-ins: record the dry sound and re-amp it afterwards. But this is a hassle and it never really works with overdriven sounds. And on top of all this, my ears are telling me the latency as measured by perceptual attack rather than physical onset is somewhat more. In fact, my 1998 vintage POD is more playable than the Kemper!

And separately on your other points - it may well be the case that many recorded guitar sounds these days are so processed by the time they're on a record that they've stopped sounding like real amps. This raises another issue which is: I wonder whether the reason some of the sounds on my 1998 vintage POD sound - to me - better than Kemper is because the developers at the time would have probably been about the same age as me at the time i.e. around 30 +/- and therefore grew up listening to the same sort of music I did and tried to emulate those guitar sounds. Whereas now, who cares what a "good guitar sound" was like in the late 70s and 80s? Who even knows how to do it these days? Some of the mics used on the Kemper profiles weren't invented in the 70s/80s. And it's rare to find a profile with e.g. an SM57 and MD421 (a classic combination). And so on.

Thanks for all the comments. I read somewhere that guitarists often buy new gear, and then worry about why it doesn't sound like their old gear. And then they try and MAKE their new gear sound like their old gear. Maybe there's some of this going on with me... HOWEVER, I find it impossible to play a semi-quaver (or 1/16th note as our transatlantic friends would call it) Nile Rogers-style funky guitar part accurately with the Kemper. I find it similarly impossible to chug in time - properly in time - at 120bpm with a standard rock overdrive sound. The culprit in both cases is Kemper latency and, IMHO, that problem with the lack of attack on the note. Either of the above musical endeavours is totally doable with my old 1998 POD. The Kemper to me, doesn't sound anything like my Brian May AC30, My Marshall TSL, my Cornford Harlequin, my Marshall 4210 combo and so on and so on. One difference though is, it doesn't hum, it doesn't have room pings, resonances and all the, errrrm, quirks of recording a real amp. Neither does it have the wires, mess and noise of a real amp. In the past, sometimes I've got a great recorded guitar sound with a real amp, but often I don't. And even if I do, reproducibility is a problem. All this is why I bought the Kemper. It's therefore sobering to find out that, after a couple of months of pretty systematic testing of it, that Kemper basically has all the same issues as a 100 quid software plug-in: i.e. latency, lack of defined attack, flat sound, lack of harmonics etc. etc. And - from the comments so far - it sounds like I'm actually not really doing anything "wrong", it's just that "digital isn't for me". So, no practical tips on switching off Pure Cabinet, or setting "Space" to Headphones only, or messing around with Tube Shape, switching cabinets assuming I'm using a merged profile etc. etc. etc. Oh well, looks like I wasted my money...!

Wheresthedug - I am impressed! 20mS of latency is 40 ticks at 125bpm. Or to put this in real world terms, that's a perceptible snare flam or like someone clapping slightly out of time.

Here's another experiment for you to try:

Set up a midi drum loop at 125bpm. Then move ONLY the Snare backwards (or forwards) 40 ticks (=20ms) and try playing along with this. Alternatively, move ONLY the Kick (backwards or forwards 20mS). Or if you prefer leave the Kick and Snare and only move the Hi-hat 20mS. Then try playing along with any of these permutations.

Another variation is to have a click going and have the entire drum midi either +/-20mS and try tracking with both click and offset midi drums.

If you can cope, as I said earlier you're blessed. I can't!

People say to me: "what the heck, 20mS is 1/50th of second". I reply, "yes". But equally, at 125bpm a semiquaver (1/16th note for US friends) lasts 120mS. So 20ms is 1/6th of a semiquaver or, put another way, 20mS of latency is like having semi-quavers played approx. 17% out of time. When I think of latency this way, I feel less bad about my inability to deal with it!

Here's what some other people - Yamaha - say about latency:

http://www.yamahaproaudio.com/…ter5/05_absolute_latency/

In summary, to save the hassle of booting up the link:

Signal path latency for in-ear monitor system:

1.15 - 2 ms Playable without any big problem.

2 - 5 ms Playable, however tone colour is changed.

5 - 10 ms Playing starts to become difficult. Latency is noticeable.

>10 ms Impossible to play, the delay is too obvious.

Kemper's latency, according to the manual, is 3.5mS or (I believe) if you hit the constant latency button 4.5mS. And this is plugging a guitar directly into Kemper and listening on headphones also plugged directly into Kemper. If one then goes via an audio interface, even with direct monitoring another cycle of ADC / DAC conversion is added and you're up to the circa. 5mS where, according to the Yamaha-latency-Beaufort-scale, latency starts to become a problem. This is Kemper.

For comparison, the declared latency of AmpliTube 4 is a mere 0.2mS. However, the problem with AT4 (and its ilk) is that to use it you need to software monitor. And for my set-up (probably not untypical) round-trip latency @64 samples I/O buffer is 5.8mS (even at 32 samples it's 4.3mS). Add the 0.2mS AT4 latency and (at 64 samples) you're up to 6mS cumulative latency and into storm-brewing-Yamaha-Beaufort-scale latency.

The only solution I've found is to split my guitar signal (analogue-ly) and send one split to my 1998 POD and the other to the Kemper. Each split then goes into the Apogee on Direct Monitoring and I monitor only the POD sound and record the Kemper. POD is not latency-free, but it's better than Kemper. And this produces monitoring sound which is (to my ears) in time with my playing. I can then re-position the Kemper track to compensate for latency afterwards. OR I can take it one stage further, and monitor with POD and record a dry DI and re-amp the latter (with AT4, GR5, Waves GTR3, Kemper or real amp). But, at the end of the day this is 1) a hassle, and 2) sobering that latest technology Kemper has an effective cumulative latency performance that is worse than a 20 year old POD.

I know I seem to have a gene in me which objects to latency, and this is a cross I must bear! But, equally, the above monkey maths are the facts.

More subjective is that, in dusting down my old POD for the above operation, I was struck by the other problems mentioned above in relation to the Kemper sound: lack of attack transient, flat sound, too much bass, too little harmonics and so on. POD may be 20 years old, but it stands up remarkably well. It it not perfect by any means - for example, there is a weird notch EQ dip about 1.3kHz on some Marshall presets that you don't get on the real thing or AT4 / GR5 or indeed Kemper Marshalls. This is a bit like that 750Hz notch on a bass SansAmp Bass DI which - to some tastes - mangles the sound of bass (and the new SA Bass DI now has a mid control added). Strange.

Anyway, thanks for all the posts. It seems like a) I am in fact not doing anything fundamentally wrong, b) there is a latency problem with Kemper if, like me and Yamaha, you notice these things, and c) the "sound issues" are subjective.

On c), if anyone knows of profiles that are recorded with just an SM57, or SM57/MD421 pair or similar i.e. the old fashioned way (no ribbon mics, or room condensors etc.) please let me know. Also, it would be nice if the SM57 wasn't completely jammed up against the cab grill (check out the SM57 manual - it recommends 6-12 inches distant for mic-ing up a guitar amp) and without the amp bass control on 11. Just a few decent Marshalls at sensible levels off gain, an AC30 from clean to flat out and maybe some clean Fenders for my occasional forays into funk playing - that's all I really need. Any and all such profile suggestions gratefully received.

And then I can use Kemper as intended when I bought it, which is to record guitar silently with headphones, and without wires, mess, hum and buzz... ...and without annoying my wife or disturbing my kids' studies!

I won't be around for the next few days, as I'm off to visit my Dad who has just had a knee replacement operation. I am going to enquire about getting my latency aversion gene removed, but I'm not sure they do this on the NHS!

It's not anything to boast about, but I definitely can (notice a few mS of latency). I think it's the combination of the Kemper 3.5mS / 4.5mS and a bit more once you add an audio interface, even using direct monitoring, where the extra ADC / DAC stages push the total over 5mS. We're talking about recording with headphones here, and endeavouring to "get it right" in terms of playing. Not live with back line, drummers etc. (that's different, obviously). FWIW, I don't think it's just the Kemper latency, it's the issues with the Kemper sound (lack of a proper transient attack on driven sounds etc., all as mentioned above).

Also as mentioned, I'm probably an average musician. I started playing the piano aged 6 and did all the grades, but I realised I was never going to be a concert pianist. I took up the guitar aged 14 and it was a lot more fun! The digital recording innovations of recent years mean I can actually get some of the sounds out of my head and onto disc (which, back in the days of Tascam 144s etc. didn't really happen!).

BUT, average or rubbish musician, I notice latency. And I'm not alone as per that Yamaha latency article earlier in the thread.

Anyway, it is what it is - and Kemper is not as good latency-wise as a 1998 POD. It just isn't.

Btw, one thing I really like about the Kemper is that you can't - at least I can't - really tweak the profiles effectively. If it doesn't sound good at the outset, find another profile and move on. This is not the case with even plug-in amp. emulators, where the temptation and opportunities to tweak are irresistible. For someone like me who should never go to a restaurant with a long menu (otherwise I will never decide what to order...), too much tweakability is a bad thing.

So, to cut to the chase, what I think I need is some SM57 and / or MD421 profiles, no room mics, no ribbons, sensible levels of gain for an old timer like me, a few classic amps, SM57 not too close and bass not on 11. Then I suspect all the re-amping palava will be worthwhile.

Atlantic. Even if I plug the guitar and headphones both directly into Kemper, that 3.5mS latency - to me - drags. The sound is behind my playing and I notice it, and everything deteriorates. Let's call this scenario 1.

If (and let's call this scenario 2) I plug Kemper and headphones into my Apogee interface and listen through the Apogee in direct monitoring mode, it's a bit worse due to an extra round of ADC / DAC conversion in the Apogee (direct monitoring is not zero latency because of the ADC / DAC). I reckon the cumulative latency in scenario 2 is about 5mS which, according to sources like Yamaha (please see earlier in this thread), is where latency starts to be a problem for musicians having to deal with it. This is my experience (it's a problem...).

A test is to do all this with all amp / cab / FX sections in the top 1/2 of Kemper disabled, thus in theory you're just getting a clean DI sound. Kemper still - to me - drags in both scenarios (and obviously scenario 2 is a little bit worse).

When amp / cab etc. get switched on, to me - and this may well be subjective - it's worse again because you can't hear the attack of the note properly. A real amp and cab - even on a high gain setting - has some "thwack" when you hit the strings. This, to me, is missing in Kemper and - again for me - it makes it hard to play properly in time.

Thanks.

It's more like 5mS latency when you take account of using an audio interface, even in direct monitoring mode.

And it's not just me. This is what Yamaha say:

http://www.yamahaproaudio.com/…ter5/05_absolute_latency/

In summary:

signal path latency for in-ear monitor systems

1.15 - 2 ms Playable without any big problem.

2 - 5 ms Playable, however tone colour is changed.

5 - 10 ms Playing starts to become difficult. Latency is noticeable.

>10 ms Impossible to play, the delay is too obvious.

I'm surprised more musicians don't notice this.

Finally - and this is the real killer - the latency performance of Kemper is materially worse than a 20 year old POD 2.0.

My bad though - all of this is in the public domain, caveat emptor and all that!