Colinear Acoustics - new 8 channel DSP preamplifier

[Lucerne]

Thank you, I missed that…I’ll contact them again next week.

 

[Halbknapp]

What i found out (not me but want to bring to attention): Output seems inverted (impulse Response is negative and other way around then on other devices).

In Addition sometimes Changes are not commited to the device when pressing apply (even the * marking on the profile that indicates a not comitted Change stays the same). Only exporting and importing the settings will help, otherwise they are lost on reconnect.

On the rightmost PEQ the tooltips popping up will always obstruct your view of the value setting after clicking into the field to input something (move your mouse away helps but still annoying). And last but not least the Arrow up/down Value Change in the Q Value of a PEQ is too granular (changes a Q of 1.000 to 1.001 -> more sense to change to 1.100).

When Switching Profiles the display of the profile you would switch to onscreen is too tiny. I cant read it safely from more then a meter away. Thats a pity as switching is so smooth and much faster then on a minidsp flex.

Just for safety reasons i find it very appealing that you can commit changes to profiles not in use and it is almost impossible to accidentally change Profile or change something on a running system just by pressing somewhere (as you always have to commit).

 

[Halbknapp]

Tldr: colinear has (remote controlled) volume control after the dsp stage so you can't simply apply boost without consequences as you can with minidsp that would reduce the input on volume control and therefore have that much headroom. If you boost on colinear you have to lower the corresponding (or overall) input sensitivity by that amount.

Suspected, not fully confirmed:
Another one very big difference from colinear to minidsp seems to be the handling of volume control. Minidsp will scale down the input signal and Colinear will scale the output signal. That means you have to watch out when boosting a signal. I ran into that on my active speaker where the Woofer has a 5db boost at 40hz and sometimes the bass sounded like the speaker had a whistling leak on louder volumes. However pc sweeps (at not full scale ) were always clean and I could hear nothing when wandering around the speaker. Only when using a gliding sinewave generator at almost full scale I noticed severe distortion at 40hz (and at not very high absolute volume). Reducing the generator Volume in 0,1db steps reduced the distortion and made it go away in one single step. I then checked my gain structure and reduced input on colinear dsp to -5db and now I could increase the remote controlled volume setting on the dsp up until -3db (from - 25 before) for the clipping to reappear.
Thats not that big of a deal but something I forgot to take care of as minidsp flex would reduce the input signal on volume control and therefore not digital clip even if you boost a lot just until you run into the physical output limits of the unit.

 

[ghemink]

Tldr: colinear has (remote controlled) volume control after the dsp stage so you can't simply apply boost without consequences as you can with minidsp that would reduce the input on volume control and therefore have that much headroom. If you boost on colinear you have to lower the corresponding (or overall) input sensitivity by that amount.

Suspected, not fully confirmed:
Another one very big difference from colinear to minidsp seems to be the handling of volume control. Minidsp will scale down the input signal and Colinear will scale the output signal. That means you have to watch out when boosting a signal. I ran into that on my active speaker where the Woofer has a 5db boost at 40hz and sometimes the bass sounded like the speaker had a whistling leak on louder volumes. However pc sweeps (at not full scale ) were always clean and I could hear nothing when wandering around the speaker. Only when using a gliding sinewave generator at almost full scale I noticed severe distortion at 40hz (and at not very high absolute volume). Reducing the generator Volume in 0,1db steps reduced the distortion and made it go away in one single step. I then checked my gain structure and reduced input on colinear dsp to -5db and now I could increase the remote controlled volume setting on the dsp up until -3db (from - 25 before) for the clipping to reappear.
Thats not that big of a deal but something I forgot to take care of as minidsp flex would reduce the input signal on volume control and therefore not digital clip even if you boost a lot just until you run into the physical output limits of the unit.

Ahh, I noticed something similar, sounded like my purifi woofer bottomed out on some crazy bass tracks while I was NOT pushing full output (at least I think so). I just reduced the input volume setting to take care of it like you do, compensating with the max EQ amount. Actually from a DSP headroom point of view, this approach should be superior as the DSP will always get the full range input signal to process, the more bits it gets at the input of all the DSP calculations, the better it should be, the volume control at the output sounds like the most technically correct solution to me. The software could give a warning to say “hey, you are boosting your EQ with xdB, you may want to reduce your input volume with xdB to prevent digital clipping” I prefer it this way as I feel it is the more correct solution from an engineering point of view.

 

[Draki]

Also there is the option of setting the output level from 2 to 2.5 V (SE) and from 4 to 5 V (Bal). It is about 2 dB gain, but still...
Be aware of your amps input sensitivity.

 

[Multiway]

Tldr: colinear has (remote controlled) volume control after the dsp stage so you can't simply apply boost without consequences as you can with minidsp that would reduce the input on volume control and therefore have that much headroom. If you boost on colinear you have to lower the corresponding (or overall) input sensitivity by that amount.

Suspected, not fully confirmed:
Another one very big difference from colinear to minidsp seems to be the handling of volume control. Minidsp will scale down the input signal and Colinear will scale the output signal. That means you have to watch out when boosting a signal. I ran into that on my active speaker where the Woofer has a 5db boost at 40hz and sometimes the bass sounded like the speaker had a whistling leak on louder volumes. However pc sweeps (at not full scale ) were always clean and I could hear nothing when wandering around the speaker. Only when using a gliding sinewave generator at almost full scale I noticed severe distortion at 40hz (and at not very high absolute volume). Reducing the generator Volume in 0,1db steps reduced the distortion and made it go away in one single step. I then checked my gain structure and reduced input on colinear dsp to -5db and now I could increase the remote controlled volume setting on the dsp up until -3db (from - 25 before) for the clipping to reappear.
Thats not that big of a deal but something I forgot to take care of as minidsp flex would reduce the input signal on volume control and therefore not digital clip even if you boost a lot just until you run into the physical output limits of the unit.

From what I understand reading this DSP-8C handles this similarly to WAF Najda (of DIYaudio fame).
You have to watch input gain and boosts even out or clipping results.

Najda lights up a warning LED to tell you / also in the live running PC SW, and it's alerting enough to warn you.

I'll find out more about DSP-8C soon enough as I'm ordering one.

 

[Bjorn]

Glad to hear that Colinear Acoustics are checking implementation of Dirac Art.

The combination of Dirac Art with manual FIR for at least crossovers and manual EQ on inputs would make it stand out product.

Dirac Art is great for bass management with multiple subwoofers but shouldn't replace manual FIR or manual global correction.

 

[Digital_Thor]

Good point. Any type of digital correction should only correct what can't be corrected otherwise. Simple DSP filters and EQ here, for coax and two woofers. Integration with mains is done with a mix of MSO and manual EQ. It works really well, and I don't see much need for any other automated solution, unless I knew less or didn't like the process of fiddling with it myself.

By the way, does anyone know which type of Q this product uses?
Mine uses either constant or proportional Q, but I've noticed that MSO/REW stick to terms like RBJ and Legacy Q. Blending Q-types when dialing in things, do not give the correct result... I learned ... the hard way

 

[Kaameelis]

Colinear Acoustics had changed the Q definition they use. Before v1.3.0 and firmware 1.4 was Q defined like REW Generic/Configurable PEQ/Symmetric. Now Q is defined like REW Generic.

 

[Digital_Thor]

Colinear Acoustics had changed the Q definition they use. Before v1.3.0 and firmware 1.4 was Q defined like REW Generic/Configurable PEQ/Symmetric. Now Q is defined like REW Generic.

Interesting. Apparently there's no clear agreement on this type of value.
In my situation I simply tried and found that 'standard' EQ in MSO, seems to fit with a constant Q in my DSP. Haven't bothered to test other combinations yet.

 

[Kaameelis]

I have make tests on before v1.3.0 and firmware 1.4. and then Q was not as Colinear Acoustics told, REW generated EQ where totally wrong, with Configurable PEQ/Symmetric I get correct results, but to import EQ you need to manipulate the REW file headers.

 

[beresniak]

Glad to hear that Colinear Acoustics are checking implementation of Dirac Art.

That's great news! I asked Colinear a few months ago about the possibility of their collaboration with Dirac, and they replied that they don't plan to do so at the moment. Can you share how you obtained this information?

 

[Bjorn]

That's great news! I asked Colinear a few months ago about the possibility of their collaboration with Dirac, and they replied that they don't plan to do so at the moment. Can you share how you obtained this information?

I asked them directly recently and they replied they would soon contact Dirac to see about the technical requirements for integrating Dirac into the DSPs. Up to now they have been busy working on the firmware/software, which might be the reason they gave you the answer they did a few months ago. But now the firmware/software is reaching its final and stable version.

Hopefully this works out and Dirac Art will be be implemented. Fingers crossed.

 

[Premier]

Hi Community,

Colinear Acoustics is developing a new DSP device with 4 channels, which I could find interesting especially for room correction.

For those who bought their 8-channels, What are the experiences so far?
Is the setting of a dynamic loudness compensation based on ISO226 curves possible with their software?

Thanks for sharing your thoughts.

 

[Multiway]

I've had one just over 3 months.
I'm very pleased with it.

Don't know about - "Is the setting of a dynamic loudness compensation based on ISO226 curves possible?"

My experience;

Clean, but not sterile sound. Better DACs than my previous 4 in 8 out DSP, and enough horse power to do decent FIR.
Comparisons between Colinear and old solution were done on the same IIR implementation on my 3 way Multi Entry Horn + 2 tapped horn subs setup.

I tried various measuring and correction techniques, and found I most like REW psychoacoustics averaged out over 10 measuring spots across the listening sofa.
Correction against Target curve, fairly shallow XO slopes etc.
Once into it, it was straightforward enough with REW and rePhase to get results that exceeded anything I'd got before.
Many check backs as I iteratively improved the FIR.

Operation is very easy and reliable.

I found Oli very easy and open to communicate with when I had questions and suggestions.

I awaiting the next release of SW/Firmware for 'some more'..

 

[Premier]

@Multiway Thanks for sharing your experience.

With 'dynamic loudness compensation' I meant the loudness function similar to the preased one of RME ADI DAC FS. If the device has a preamp and if not yet available, I think, in case it can be also easily implemented by Colinear at anypoint in time with their firmware.

What is exactly the 'some more' you are awaiting from the next soft/firmware release?

 

[Multiway]

some more

Can't disclose this..

 

[Kaameelis]

Can't disclose this..

Dirac?

 

[Halbknapp]

I would assume dirac integration is more of a medium to long term thing. But as I understand from Oli their list of possible improvements is VERY long, including all aspects of operation from better interface, easier programming, more performance/taps, more functions and so on. Every user will probably have a slightly different list of priorities here.
However I have no clue what makes it into the next update or when it comes out (very curious though)

 

[Kaameelis]

I have understanding from Oli information that more taps is not possible without hardware upgrade, it mean also soon will be released new hardware version?