TOPIC:

Hello, crew. In the fine review of the nanoavr in the latest Stereophile issue, Kal Rubinson notes a flaw in the bass management channel summing. In the manufacturer's comments, the minidsp team agrees and says that it expected to release an updated software patch (or maybe just different instructions) on how to resolve this. Has this been done or is following the bass management instructions on the website still going to yield an inproper result? Thanks. JCR

Hi, is the review online or only in print?

So far, just in print on pages 49-55 of the July Stereophile. Kal concludes by suggesting that one can start equalizing like a pro with the nanoAVR and REW for $299, as compared to $13.599 for a Trinnov MC processor. High praise. But, what do we know about miniDSP's promise -- stated in the manufacturer's comments to Kal's review -- to release reworked software and DSP firmware to allow standard bass management implementation? The release was supposed to come in May. JCR

I'm just curious as to what he actually said.

DevTeam -- what say you all to the original question as to bass management on the nanoAVR? JCR

@Jrobbins50,

Sorry we missed that post... Had quite few traffic and lots of support tickets with everybody asking their questions...
As to the question of the Bass Management, we indeed told Kal Rubinson that we'd do an update to the DSP structure to improve the Bass management. Requiring quite a reorganization of the whole DSP structure, it just wasn't a 5min job on a Friday afternoon.. Few weeks of holidays for some core team members and a busy dev schedule later, the update is now finalized. We have few beta testers that seem to find everything fine.

All this to say that most likely by tomorrow, we'll release it! We just want to finalize the documentation hopefully else we end up with more questions than we need..
See attached the new tab of the plug-in which will basically allow you to select the LPF for each speaker rather than the overall value of the earlier version.



In the mean time, we're reworking the app note to include that section and explain how to use it.
Hoping this makes sense.

DevTeam

Dear All,

As promised and just in time for a fun week end of tuning, the updated nanoAVR plug-in with newer bass management feature is now available as a Beta under your UserDownloads section!

Note also that we've taken the time to update the application note here (www.minidsp.com/applications/home-theate...ning/bass-management
0to make sure you have a starting point. Please start reading this first so it's easier to understand what you're doing..

Finally, note that this plug-in has a complete different DSP structure (XML configuration) than the earlier plug-in. In other words, I'm afraid that you can't "load" a preview configuration to it. You'll need to copy over your settings manually.

We look forward to hearing your feedback.

Devteam

Great work everybody on the dev team.

I have a question. Is it possible to do bass management in stereo?
To me it looks like you assume that everybody wants to route the bass to a mono subwoofer output, but what if you want to route the bass from the surround speakers to the front speakers? Or if you don't use the back surround and want to use these channels for stereo subwoofer out?

The nanoAVR looks like a really great product, but to me(if I'm not mistaken) it seems like the frontend/plugin limits the hardware somewhat.
What I personally would like to see is a plugin that lets me route any input to any output with level adjustment AND band pass filtering. No mono LFE mgt tab, but rather full filtering and level adjustment on each routing.

Example:
//Front in unchanged to front out
Input FL - > Output FL, 0dB
Input FR - > Output FR, 0dB

//High pass surround out
Input SL - > Output SL, 0dB, HP(80Hz, 18dB/oct)
Input SR - > Output SR, 0dB, HP(80Hz, 18dB/oct)

//Send low pass surround to front out
Input SL - > Output FL, 0dB, LP(80Hz, 30dB/oct)
Input SR - > Output FR, 0dB, LP(80Hz, 30dB/oct)


Please don't take this as criticism on your work. This is just a suggestion from my side to make this already great product better.

With regards //Andreas

Edit - hang on, I got mixed up there. Let me program it in and try again

Example:
//Front in unchanged to front out
Input FL - > Output FL, 0dB
Input FR - > Output FR, 0dB

//High pass surround out
Input SL - > Output SL, 0dB, HP(80Hz, 18dB/oct)
Input SR - > Output SR, 0dB, HP(80Hz, 18dB/oct)

//Send low pass surround to front out
Input SL - > Output FL, 0dB, LP(80Hz, 30dB/oct)
Input SR - > Output FR, 0dB, LP(80Hz, 30dB/oct)

OK, let me try that again. You're right, this specific configuration can't be programmed into the nanoAVR. What CAN be done is lowpass filter and sum SR and SL to the LFE Mgt channel, and then mix that into FR and FL. So only the surround bass below 80 Hz is not "stereo."

Or, if one had "stereo subs" and were not using RR and RL out, then one could mix FR and SR to RR out and low pass filter, and connect to the right sub. Similar for the left sub.

I'd be a bit curious as to the need for "stereo bass" on the surround signals. By sending this to the front you are already removing the assumption that it is directional, at least in part...?

adzer wrote:

What I personally would like to see is a plugin that lets me route any input to any output with level adjustment AND band pass filtering. No mono LFE mgt tab, but rather full filtering and level adjustment on each routing.

If I understand your suggestion, this means a low pass filter everywhere there is a gain control on the routing screen? ie 64 lowpass filters.

john.reekie wrote:

OK, let me try that again. You're right, this specific configuration can't be programmed into the nanoAVR. What CAN be done is lowpass filter and sum SR and SL to the LFE Mgt channel, and then mix that into FR and FL. So only the surround bass below 80 Hz is not "stereo."

Or, if one had "stereo subs" and were not using RR and RL out, then one could mix FR and SR to RR out and low pass filter, and connect to the right sub. Similar for the left sub.

Thanks for taking the time to test this yourself.
So routing bass from surround to front have to be mono, but using two dedicated sub channels can be in stereo.

john.reekie wrote:

I'd be a bit curious as to the need for "stereo bass" on the surround signals. By sending this to the front you are already removing the assumption that it is directional, at least in part...?

Well there isn't really a need per se since I doubt I would be able to here any difference between the surround bass in only one sub channel or in both. It's just that I like the option to configure everything the way I want with no restrictions. Call it perfectionism, need for control, engineers syndrome or whatever you want

john.reekie wrote:

If I understand your suggestion, this means a low pass filter everywhere there is a gain control on the routing screen? ie 64 lowpass filters.

Yes I would like gain control and band pass(i.e. HP & LP) for every single one of the 64 possible routings. And then not just the same filter for everyone. I would like to be able to change the frequency and slope individual as well as the biquad option. I personally use different crossover frequencies for the different speakers so individual filtering for each routing would be very appreciated.

I understand that most of your customers don't need this level of configurability, but for those who do this would go a long way to make this product really perfect.
If you are worried that this would make the GUI more complicated to use you could always give the option between a basic and an advance view. I trust that the dev team would be able to come up with something that would be both easy to use and give the user the option to configure the hardware any way he likes.


Thanks again for taking the time to read my suggestions.

//Andreas

Andreas,

Just a comment with regards to your suggestion of adding 64 x HPF + LPF, providing we say we have 48db slopes (i.e. 4biquad per HPF or LPF), that's a whopping 512 biquads to be added to the already fully featured DSP structure. Bottom line it wouldn't be possible on the DSP unless that matrix mixer LPF+HPF setup is the only thing the DSP does.. Sorry..

DevTeam

devteam wrote:

Andreas,

Just a comment with regards to your suggestion of adding 64 x HPF + LPF, providing we say we have 48db slopes (i.e. 4biquad per HPF or LPF), that's a whopping 512 biquads to be added to the already fully featured DSP structure. Bottom line it wouldn't be possible on the DSP unless that matrix mixer LPF+HPF setup is the only thing the DSP does.. Sorry..

DevTeam

I know it wouldn't be possible to use them all at once. But often you don't want to route every singe input to every single output using both HP and LP. At least I don't. You could always add a max number of filters that can be used. Say you have 64*2(HP & LP) possible filters, but you could only use 25 simultaneously. I think that would be an acceptable compromise.

Well that's my thoughts on the subject. Good luck

//Andreas

Andreas,

Unfortunately, dynamic management of filters is what you're looking at (i.e. creating 512 biquads in the DSP structure flow but only allowing a certain amount to be controllable/used ). It's a conceptually a good idea but a very complex step for both the software and firmware engineers so not a Friday afternoon 5min job I'm afraid..

devteam wrote:

Andreas,

Unfortunately, dynamic management of filters is what you're looking at (i.e. creating 512 biquads in the DSP structure flow but only allowing a certain amount to be controllable/used ). It's a conceptually a good idea but a very complex step for both the software and firmware engineers so not a Friday afternoon 5min job I'm afraid..

As a software engineer myself I totally understand. This was just my thoughts and wishes.
The "easier" solution could be to add another LFE mgt. That way you could at least always route LFE in stereo if you want, but enough of this. Good luck. I'm sure you guys will do your best

ps. I just ordered a nanoAVR

//Andreas, over and out.