Optimizing the KPA for the Yamaha DXR10

I'm interested in taking sort of a scientific approach for matching the KPA to my DXR10 and since it seems to be quite popular among Kemper users it might provide helpful to others, but before that happens I think I'm going to need some help from the audio experts around here.

I have set my old Behringer Ultra Curve (DSP 8000) to take a RTA curve of the Yamaha DXR10 using its internal pink noise generator and a Peavey PVR reference microphone.

The microphone is positioned as follows:

[Blocked Image: http://www.deny.mus.br/images/dxr10_pvr.jpg]

And the resulting RTA curve is as follows:

[Blocked Image: http://www.deny.mus.br/images/ultra_curve_dxr10.jpg]

Interesting, huh? From that pic I'd say the overall response of the DXR10 is fairly flat from 80Hz through 20kHz as we'd expect, except for:

1. A slight peak around 120Hz (2.5dB)
2. A slight dip around 2.2kHz (3dB) - this is where the presence control actuates and also where harshness lives I believe
3. A slight peak from 4kHz - 8kHz (2.5dB)
4. A much more pronounced peak around 12kHz (6dB)

Before I go any further I'd like to hear ideas, opinions on whether I'm doing this right. Mic positioning for instance, I know the PVR is omnidirectional but any ideas on improving its position are welcome. Next step I think will be connecting the pink generator -> KPA FX return -> EQ -> DXR10 -> Mic -> RTA. That way I can try to compensate the DXR10 for the flattest possible response.

Quote from tylerhb

Well, perhaps you read my post that i used the DEQ2496 (the successor of the DSP8000) to flatten my JBL EONs. I am not sure if the DSP8000 has the same features and a separate RTA mic input. But i connect the KPA Master (or monitor) outputs to the input of the DEQ which then goes into the EONs. The RTA mic just goes into the RTA mic input of the DEQ.

To get the best result out of the DEQ, i did about 10 measurements with different distances and angles and stored each EQ curve. They all show the same tendency which looks similar to your curve, only with more extreme cuts and boosts. But since the DXR gets nice reviews with the KPA it seems a lot flatter compared to my EONs, which really does not sound good without the DEQ. i tried simulating a live gig situation, and brought the whole setup into a completely different room. The sound was still very nice there. But since you can recall the different curves very quickly it would mean no trouble to change the EQ to another curve which suits better to a different situation.

Thanks for the tips, I'm going to take a few more measurements and average them before drawing any conclusions. My next step will be trying to get as close as possible to a flat response using the monitor out eq, so when I tweak my profiles I'll be sure that they're well tonally balanced. Yes I know, my OCD is starting to kick in a bit harder

Quote from badtoneno

Or you could just use your ears, see what sounds good to you and in the mix & call it a day.

Unfortunately my ears are not that good
I mean, it's not like they suck but I tend to lose reference easily so I feel more comfortable relying on more accurate measurings. Of course in the end I expect that the result of all this will be more consistent tone for the FOH PA and more enjoyable tones for myself

Quote from Jimmyno

Well, so please, let us know what will your finale correcting EQ will be, since all the present and maybe future owners of DXR can enjoy a flatter monitor with a competitive price.

Will do, stay tuned

Quote from aas

Interesting... but your mic is too close to DXR10. Basically you should put the mic a the same distance of your ears for optimized settings.

I wish I could do that, but neither the Ultra Curve nor that little mic seem to have enough gain for far miking

Unless I crank up the volume a bit, last night I scared the shit out of our little dog while taking measurements which made me feel a bit guilty, it ran away barking and went to hide behind the fridge the poor thing

I'll see if I can figure out a way of doing this more consistently without tearing down the house, I'm giving it another shot tonight

So I've put the pink noise output through the FX return of the Kemper and tried to compensate for the DXR10 response using *only* the monitor out EQ like Zappledan suggested (it was my plan anyway).

Here's what the RTA screen looks like with Bass -1.0, Treble +0.5 and Presence -2.0:

[Blocked Image: http://www.deny.mus.br/images/dxr10_corrected.jpg]

Ok, but the question is "how does it sound?" Well, my first impression is that it sounds *very good*

I browsed through a few factory and user rigs and started to understand what this thing must sound like through a good pair of really expensive reference monitors. I'd say give it a try and tell me what you guys think

Quote from tylerhb

I think the best way to use it is to leave the FOH sound unchanged and just use the Behringer for the stage monitoring. That´s why i wouldnt put the EQ in the KPA loop because this would affect the FOH main out and the monitor out at the same time. You could set the monitor out to carry the master left and the direct out to carry the master right signal. These two ouputs go into the Behringer in stereo and then into your monitors for a stereo setup. If you have only 1 monitor, then just use the monitor out with the master mono signal.

If you put the RTA mic too close to your monitor you will get a lot of proximity effect, which means that the bass will be too strong. With my 15" Eons, i got the best result at about 1.5 to 2 meters distance. With a 10" system this might be a totally different story. I guess you can move the mic closer in this case. I would start at about 30 cm distance and then take further measurements, increasing the distance in 5 or 10 cm steps. If you store all the curves you can recall those later with fresh ears and decide which one sounds best.

The idea isn't really using the Behringer as my monitoring EQ, the above result was achieved by using *only* the monitor out EQ on the Kemper, no compensation on the Ultra Curve was done whatsoever. Heck, I'm into modeling basically for the smaller footprint, so no point in dragging another 2U rack to gigs

Instead of creating a new thread I've decided to do a follow up on this one since it's about the same subject (KPA + DXR10).

Lately I've been comparing a certain profile with its original and haven't been very satisfied with the results, the original sounds a lot darker and still for some reason more articulate and pleasant. So I've put a Studio EQ after the amp block in the profile and started searching for the offending frequency. Didn't expect it to be what it was since apparently the DXR10 has a subtle dip in that area, nevertheless here's the settings if you want to give it a shot:

Studio EQ (using one of the parametric bands only)
Level: -3.7dB
Frequency: 2500 Hz
Q: 0.900

Now I'm kinda wondering if the emphasis in that frequency comes from the KPA or the DXR10, it would be interesting if someone would try the above settings using a different speaker and report back with the results.

New EQ settings if anyone's interested - yes, I am very persistent

Again a Studio EQ in the "X" slot using only one parametric band, settings:
Frequency: 3,000 Hz (3kHz)
Q: 0.960
Gain: -3.3 (at around 80 dB SPL, higher volumes might require more cut)

I feel it does sound better like this, I've felt more "connected" with these settings but tried them only with a couple of profiles, will test on a few more tonight. I wish the KPA had some sort of EQ compensation curve in the master section for popular speakers like the DXR10.