Hi-
First post, thanks for having me. Still getting acclimated to the Kemper, and have not yet nailed my main amp, a Cornford Hellcat. In particular, I'm having trouble getting accurate dynamics when then gain is on.
Here's a quick A/B. Signal chain:
Les Paul Classic -> Hellcat, red channel, max gain -> pine cab -> H30 -> SM57 -> JLM Audio preamp -> Kemper -> Lynx Aurora -> Macbook.
Amp clip:
https://soundcloud.com/graphics8/hellcat-amp
Kemper clip:
https://soundcloud.com/graphics8/hellcat-kemper
What I'm hearing here in the Kemper track is over-compression, particularly in the bass. Whereas the amp track is stiff and chuggy, the Kemper track sags. This squishy sound is not unlike what happens when you reamp a track too hot into an amp. However both of these clips were live -- no reamping.
In addition, the Kemper is picking up a ton of sub. The '57 does not put out much below 100hz, but the Kemper seems to think so. You should be able to hear this in good headphones or studio monitors. Additionally, here's the Match EQ curve in Logic:
http://img542.imageshack.us/img542/9294/he…mpermatcheq.png
Aside from the huge bass roll-off, the rest of the curve is actually very close. Reasonably flat from 200hz to 1k. And dead flat from 1k to 10k. You can click this curve on and off in Logic and the mids and upper mids sound essentially identical.
So... If this were a real amp, I'd assume I was simply going into the amp too hot. The Les Paul has a 500T in the bridge which is a very hot pickup, but I have the "Clean Sens" at 4 and I'm not getting any red lights.
Dropping the gain (or "Dist Sens") doesn't help - that just reduces the overall saturation, not the bass strangulation that's happening here.
Definition is already at 9.7 -- nowhere to go from there.
Filtering out bass using "Studio Eq" before the stack just eviscerates the sound. And frankly should not be necessary if the profile is correct.
As an additional test, I installed the "Hellcat Red Channel" profile from the rig exchange, increased the gain to 7.5 to match my profile, and swapped cabs with my profile. Here's what that sounds like:
https://soundcloud.com/graphics8/hellcat-red-kemper
Still pretty squishy.
Thoughts? Is anyone else having this issue with high gain profiles?
FYI:
For the "refining" phase, I simply played the same riff a few times. From the manual, Wiki, and forum, there seems to be endless speculation and no real consensus on what the box actually needs to hear during refining. My own experimentation has produced widely varying results -- "definition" values and frequency curves all over the map. For the mean time, I've settled on using the test riff itself to introduce the fewest variables.
Moving forward, more transparency on the refining phase would be welcome. If any guitar will suffice, as the manual states, then the Kemper should probably just play its own refining signals to eliminate the needless fumbling in the dark. By comparison, creating IRs of speaker cabs is a clear-cut, repeatable, and highly accurate process.
Thanks!