TOPIC:

Hey Guys,
I´ve a Problem with my DDRC-24.

At higher levels (but not extremely high) I have disturbing noises at high frequencies and I have no idea why ... My custom Target Curve is relatively modest, and I'm sure it's not because of the speakers.

I have a 2.2 setup and use a Marantz NR1508 as a pre-amp, then go from the stereo pre-outs to the DDR24 and from there each into an amp for the speakers. For the two Infinity Ref1260w subwoofers I use a Behringer KM1700 amplifier and for the Disco-M speakers I use the PWR-ice125 amplifier without eq.

I hope someone can help me.

For additional Information, I´ve measured my output voltage outcoming of the Marantz Pre-Outs
and have stated that this is a maximum of 0.63V and clean without clipping only 0.14V. Could that be a problem? The input sensitivity of my Behringer amplifier I can set to 0.77V, 26dB or 1.44V. Could it be that my receiver just is not enough as a pre-amp?

The 2x4HD and DDRC-24 are both capable of outputting 2Vrms at full volume which can clip the input on some devices.

Nearly all audio measurements are in Vrms but most cheap DMM only measure Vpp so be sure to convert (Vrms = 0.3535 * Vpp)

Does setting the sensitivity on the Behringer KM1700 to 1.4Vrms help?

oh I have just noticed a mistake. I do not have the KM1700 but the KM750.
The thing is that I have noticed the noise so far only in the treble or midrange and the normal speakers are indeed operated with the pwr, which also has 2vrm. Unfortunately, I do not have that much idea of ​​the electrical way, I've always dealt only with room acoustics, etc.

I thought maybe the receiver is clipping. Do you mean a multimeter? That means the pre out will only make 0.3535 * 0.14 Arms :O

oh I just see that I have the PWR currently on 1Vrms. Could be helpful to put that on 2Vrms.

ok i tested it now and it got worse than before. I also turned off the subwoofer and switched off dirac and always the same. I once inserted an audio file in which you can hear the problem well. Even if I stop at the end of the memo, there is such a crackle.

@Spleentease

Most likely a clipping in your chain indeed. Typically quite simple to investigate.
- Inside the DSP, there are RMS in/out meters. Did you check them.
- Please share your dirac Project and DDRC-24 config file (xml). That will be more useful I think..

DevTeam

yes, I've looked over it in ddrc times and the inputs are definitely in the red area when it clipped or do you mean something else?
I've attached the files

mhm can't upload the project (.dprj)for some reason.

does anyone have an idea why?

I am now really confused about the subject of gain structure. I know in which setting my av-receiver delivers an undistorted signal, but I do not know how I have to adjust this with respect to my amplifier. What should the input gain controls stand for? Do I use those with or without active dirac? Can or should I set the output level of the pwr-ice 125 in the software to maximum? What do I do if everything is set correctly, but the volume is not enough for me? I just can not get on right now.

@Spleentease:

" I've looked over it in ddrc times and the inputs are definitely in the red area "
- Well, you've got your problem then... If it's at the input, you're feeding too much signal maybe. Bypass Dirac Live and see if you're also clipping. If you are, you need to lower your preamp out so you don't clip the DDRC-24.
Solve that issue before trying to go further as that is the key issue to solve here.. Agree?

- For sharing file, you can zip it or use an online file sharing (Eg.. google drive link)

DevTeam