TOPIC:

Hi

I'm trying to understand the target curve file format in order to generate them in an external text editor and load them into DLCT. Hope someone can shed some light on this.

Here's an example of a target curve file:

Hi Markus, it looks like the first group is (frequency, dB) per line of the little dots. rest might need some guesswork/ experimentation.

Hi John

What I've found so far:

LOWLIMITHZ/HIGHLIMITHZ
No filter is applied beyond these frequencies. The lower limit seems to be 10Hz, the upper limit 24000Hz.

BREAKPOINTS
Defines the points that are "connected" by the target curve. They need to be higher than LOWLIMITHZ and lower than HIGHLIMITHZ.

HPSLOPEON/LPSLOPEON, HPCUTOFF/LPCUTOFF, HPORDER/LPORDER
Lowpass/Highpass filter (on/off, frequency, slope). Activated by setting HPSLOPEON/LPSLOPEON to 1.
Not sure why this isn't available in the user interface of the DLCT. I consider a high pass filter an essential feature for people that want to protect their ported subs from over-excursion.

Great info, more options to experiment with! I think you meant high pass for over-excursion protection.

Yep, corrected.

HPSLOPEON/LPSLOPEON - nice discovery!

Is that file for a single channel or all of them?

You load it for a group of linked channels

Ok that makes sense then. What I want to know and if someone tested it please do tell but if I make a high pass filter and set it to 12HZ which is where I need it to start at will it simply stop at 10hz or will the curve go below the 10hz cut off point?

Has anyone tried this yet as I have a subwoofer that is ported to 12HZ and need to keep the driver safe and sound.

Well, it's an undocumented feature... if you depend on it, I would suggest use a separate 2x4?

I do have a 2x4 if need be but I was hoping to avoid having a other item in the chain. I guess I could try it if I end up getting one and measure with rew and see what it does.

Group of linked channels? Could the HPF/LPF be set differently for the sub vs the rest of the channels? If so could that be used for bass management instead of using the xover in the AVR?

merlin wrote:

Group of linked channels? Could the HPF/LPF be set differently for the sub vs the rest of the channels?

Yes. You can load any target curve for any group of channels. If you don't have grouped channels then you could even load an individual target curve for each channel.

merlin wrote:

If so could that be used for bass management instead of using the xover in the AVR?

No because high/low pass filtering is just one step in bass management. The other step is to sum channels in the subwoofer channel. The latter can't be done in the 88A.

The LOWLIMITHZ can be set below10hz I set mine to 5hz will that allow for a high pass filter to be applied to that point? I also noticed that when you do this and load that curve you can drag a point off the area that you can see and draw a curve down to single digits I am really thinking about testing this out with rew and see what it does. Any thoughts on such?

^
I got filter errors from DLCT when setting low limit below 10Hz.