Minidsp/Dirac/Bass management noob confusion

[Bornsceptic]

Hi!

First time poster but have been lurking the forum for almost a year. And I must begin by saying how impressed I am by the level of knowledge here. I was so happy when I found ASR, but also equally baffled by the fact that I have been spending so many years being totally fooled by reviewers, store “experts” and the audio industry in general. Also, how is it possible that so many myths continue to live and thrive, and not only that, are actually considered basic knowledge? For example, the myth about amplifier colouring sound - how is it possible this is considered a “truth” and a “fact” by 99% of everyone involved in Hifi? Scary.
So thank you @Amir and everyone here for the work that you do!

But enough rambling. I actually need to ask a question and have some advice on the subject of dsp and subwoofers.
First off, I’m on a limited budget so want to upgrade my system. I currently have a pair of Atohm GT-1 bookshelves and a Rel T5 sub. Upgrading, to get rid of bad room modes on bass and overall performance, I’m thinking of either: 1) new sub with built in DSP, most likely a SVS sb1000pro or 2) MiniDSP DDRC-24. Whatever I don’t buy will be the second purchase down the line.

Now to the question and confusion. I’ve really been trying to read up on this on this and MiniDSPs forum, but since I’m neither rather technical nor experienced in this I’m afraid some of the explanations are lost to me. My aim is to get good bass, and of course also good sound across the freq curve, and a DSP is a way to accomplish that, and Dirac sounds like a very good solution for someone not to eager to spend hours and hours learning REW and tweaking and tuning. What I don’t understand is the thing with Dirac “bass management”? I get that the Minidsp only has two inputs, not a separate one for the Sub. But isn’t the point getting the sound from source (dac) into the Minidsp, eq’d and tuned with Dirac, and then output to L, R and Sub in an altered way (differently depending on if it’s frequencies for the sub or for the stereo speakers)? Why all the discussions on Minidsp not having Dirac Bass management? What’s missing in the above setup?

And, if I get a sub with built in DSP and correction features as the SVS 1000 pro, will I likely solve most of my sound issues anyway and not bother with the Minidsp until later? In short, since I already have a sub, although not a super-good one, should I start with a MiniDSP or the SVS, since that already has built in DSP, albeit only for bass?

Sorry if above appears confused, probably because I am

 

[AdamG]

Hi!

First time poster but have been lurking the forum for almost a year. And I must begin by saying how impressed I am by the level of knowledge here. I was so happy when I found ASR, but also equally baffled by the fact that I have been spending so many years being totally fooled by reviewers, store “experts” and the audio industry in general. Also, how is it possible that so many myths continue to live and thrive, and not only that, are actually considered basic knowledge? For example, the myth about amplifier colouring sound - how is it possible this is considered a “truth” and a “fact” by 99% of everyone involved in Hifi? Scary.
So thank you @Amir and everyone here for the work that you do!

But enough rambling. I actually need to ask a question and have some advice on the subject of dsp and subwoofers.
First off, I’m on a limited budget so want to upgrade my system. I currently have a pair of Atohm GT-1 bookshelves and a Rel T5 sub. Upgrading, to get rid of bad room modes on bass and overall performance, I’m thinking of either: 1) new sub with built in DSP, most likely a SVS sb1000pro or 2) MiniDSP DDRC-24. Whatever I don’t buy will be the second purchase down the line.

Now to the question and confusion. I’ve really been trying to read up on this on this and MiniDSPs forum, but since I’m neither rather technical nor experienced in this I’m afraid some of the explanations are lost to me. My aim is to get good bass, and of course also good sound across the freq curve, and a DSP is a way to accomplish that, and Dirac sounds like a very good solution for someone not to eager to spend hours and hours learning REW and tweaking and tuning. What I don’t understand is the thing with Dirac “bass management”? I get that the Minidsp only has two inputs, not a separate one for the Sub. But isn’t the point getting the sound from source (dac) into the Minidsp, eq’d and tuned with Dirac, and then output to L, R and Sub in an altered way (differently depending on if it’s frequencies for the sub or for the stereo speakers)? Why all the discussions on Minidsp not having Dirac Bass management? What’s missing in the above setup?

And, if I get a sub with built in DSP and correction features as the SVS 1000 pro, will I likely solve most of my sound issues anyway and not bother with the Minidsp until later? In short, since I already have a sub, although not a super-good one, should I start with a MiniDSP or the SVS, since that already has built in DSP, albeit only for bass?

Sorry if above appears confused, probably because I am

Welcome Aboard @Bornsceptic.

 

[Dougey_Jones]

Now to the question and confusion. I’ve really been trying to read up on this on this and MiniDSPs forum, but since I’m neither rather technical nor experienced in this I’m afraid some of the explanations are lost to me. My aim is to get good bass, and of course also good sound across the freq curve, and a DSP is a way to accomplish that, and Dirac sounds like a very good solution for someone not to eager to spend hours and hours learning REW and tweaking and tuning. What I don’t understand is the thing with Dirac “bass management”? I get that the Minidsp only has two inputs, not a separate one for the Sub. But isn’t the point getting the sound from source (dac) into the Minidsp, eq’d and tuned with Dirac, and then output to L, R and Sub in an altered way (differently depending on if it’s frequencies for the sub or for the stereo speakers)? Why all the discussions on Minidsp not having Dirac Bass management? What’s missing in the above setup?

Not sure if this reply will be helpful, but, Dirac and REW don't really care HOW you're reproducing your sound, they're taking measurements and then allowing you to perform EQ in the digital domain. Once the EQ is performed, you either send the EQ'd digital signal, or depending on the hardware you purchase and configure, EQ'd analog signal and that goes into whatever amplifier/receiver/integrated/powered speakers you may have down chain.

 

[richard12511]

Hi!

First time poster but have been lurking the forum for almost a year. And I must begin by saying how impressed I am by the level of knowledge here. I was so happy when I found ASR, but also equally baffled by the fact that I have been spending so many years being totally fooled by reviewers, store “experts” and the audio industry in general. Also, how is it possible that so many myths continue to live and thrive, and not only that, are actually considered basic knowledge? For example, the myth about amplifier colouring sound - how is it possible this is considered a “truth” and a “fact” by 99% of everyone involved in Hifi? Scary.
So thank you @Amir and everyone here for the work that you do!

But enough rambling. I actually need to ask a question and have some advice on the subject of dsp and subwoofers.
First off, I’m on a limited budget so want to upgrade my system. I currently have a pair of Atohm GT-1 bookshelves and a Rel T5 sub. Upgrading, to get rid of bad room modes on bass and overall performance, I’m thinking of either: 1) new sub with built in DSP, most likely a SVS sb1000pro or 2) MiniDSP DDRC-24. Whatever I don’t buy will be the second purchase down the line.

Now to the question and confusion. I’ve really been trying to read up on this on this and MiniDSPs forum, but since I’m neither rather technical nor experienced in this I’m afraid some of the explanations are lost to me. My aim is to get good bass, and of course also good sound across the freq curve, and a DSP is a way to accomplish that, and Dirac sounds like a very good solution for someone not to eager to spend hours and hours learning REW and tweaking and tuning. What I don’t understand is the thing with Dirac “bass management”? I get that the Minidsp only has two inputs, not a separate one for the Sub. But isn’t the point getting the sound from source (dac) into the Minidsp, eq’d and tuned with Dirac, and then output to L, R and Sub in an altered way (differently depending on if it’s frequencies for the sub or for the stereo speakers)? Why all the discussions on Minidsp not having Dirac Bass management? What’s missing in the above setup?

And, if I get a sub with built in DSP and correction features as the SVS 1000 pro, will I likely solve most of my sound issues anyway and not bother with the Minidsp until later? In short, since I already have a sub, although not a super-good one, should I start with a MiniDSP or the SVS, since that already has built in DSP, albeit only for bass?

Sorry if above appears confused, probably because I am

While you do get some built in PEQ with the SB1000, I don't think it supports multiple subwoofers, and it only has 3(?) bands. A miniDSP with Dirac should be considerably more effective with the EQs it can generate.

 

[Bornsceptic]

Not sure if this reply will be helpful, but, Dirac and REW don't really care HOW you're reproducing your sound, they're taking measurements and then allowing you to perform EQ in the digital domain. Once the EQ is performed, you either send the EQ'd digital signal, or depending on the hardware you purchase and configure, EQ'd analog signal and that goes into whatever amplifier/receiver/integrated/powered speakers you may have down chain.

Indeed this is how I understood it. So the Eq part is fairly straight-forward for me to grasp. But then there is obviously something else related to "bass management" apart from only Eq, that I don't get with the MiniDSP and Dirac...? Time-alignment? Phasing? Other?

While you do get some built in PEQ with the SB1000, I don't think it supports multiple subwoofers, and it only has 3(?) bands. A miniDSP with Dirac should be considerably more effective with the EQs it can generate.

Great points; I do actually already have an additional sub in the same living-room (now used for HT), so if I figure out a way to use it in the stereo set-up that could be very interesting. Also, didn't think about only 3 bands! I have yet to do any measurements in my room, but I suspect there will be need for more than 3 areas on the curve needed to be fixed

 

[fluid]

I get that the Minidsp only has two inputs, not a separate one for the Sub. But isn’t the point getting the sound from source (dac) into the Minidsp, eq’d and tuned with Dirac, and then output to L, R and Sub in an altered way (differently depending on if it’s frequencies for the sub or for the stereo speakers)? Why all the discussions on Minidsp not having Dirac Bass management? What’s missing in the above setup?

To get the Dirac Bass Management features you need to be using one of the DDRC-88 A or D units and the DDRC-88BM plugin. The stereo MiniDSP Dirac units are not able to access that function.

https://www.minidsp.com/applications/home-theater-tuning/bass-management-with-ddrc-88bm

 

[Bornsceptic]

To get the Dirac Bass Management features you need to be using one of the DDRC-88 A or D units and the DDRC-88BM plugin. The stereo MiniDSP Dirac units are not able to access that function.

https://www.minidsp.com/applications/home-theater-tuning/bass-management-with-ddrc-88bm

Thank you. However, I knew that the DDRC-88 was needed for DBM. What I still don’t quite get, even having read the text in your link, is what’s actually the difference between Eq’ing the bass with Dirac and a DDRC-24, and using a DDRC-88 and performing ”Bass management”. What am I missing?
I believe these are obvious things for most of you technically savvy people on this forum, but for me it’s far from easy to understand .

 

[abdo123]

Thank you. However, I knew that the DDRC-88 was needed for DBM. What I still don’t quite get, even having read the text in your link, is what’s actually the difference between Eq’ing the bass with Dirac and a DDRC-24, and using a DDRC-88 and performing ”Bass management”. What am I missing?
I believe these are obvious things for most of you technically savvy people on this forum, but for me it’s far from easy to understand .

with bass management Dirac would be able to set crossover frequencies, delays (phase), filters to each and every one of the subwoofers.

with DDRC-24, Dirac can only apply filters to ‘Left channel’ and ‘Right channel’ so you have to phase align and set the crossover between subs and mains.

 

[fluid]

The DDRC-24 will apply any correction to the Left and Right stereo channels. The bass management option with more channels will allow corrections to be made to individual subwoofers. This will allow the subwoofers to work together to reduce spatial variability (the difference in response throughout the room) and provide a better frequency response and reduce modal ringing.

Some background reading on the use of multiple subwoofers would be a good idea.

http://www.gedlee.com/Papers/multiple subs.pdf

https://mehlau.net/audio/multisub_geddes/

Edit abdo123 got there first

 

[Bornsceptic]

Ah, thank you both @fluid and @abdo123 ! So, very simplified, bass management will be mostly a huge benefit when using multiple subs?

 

[abdo123]

Ah, thank you both @fluid and @abdo123 ! So, very simplified, bass management will be mostly a huge benefit when using multiple subs?

not just that, bass management is for integrating any subwoofer(s) to main speakers in general for inexperienced people.

 

[Bornsceptic]

not just that, bass management is for integrating any subwoofer(s) to main speakers in general for inexperienced people.

Aha! Now you got me confused again So when we talk about subwoofer integration, you would say that Bass Management is needed, and only using Dirac live for stereo as in the case of the DDRC-24 would NOT be a tool for helping me integrating my sub? Or is it a case of the former being a 90-100% solution and the latter a 50% (that will still imorove my integration a lot compared to nothing)?

 

[abdo123]

Aha! Now you got me confused again So when we talk about subwoofer integration, you would say that Bass Management is needed, and only using Dirac live for stereo as in the case of the DDRC-24 would NOT be a tool for helping me integrating my sub? Or is it a case of the former being a 90-100% solution and the latter a 50% (that will still imorove my integration a lot compared to nothing)?

To integrate a subwoofer, you need to:

1) Gain match the speakers to the subwoofer, SPL matching is also possible but not as effective. you will use the MiniDSP for volume control from now on.

2) apply crossover, usually low pass 4th order LR (24db/oct) at 80Hz to the subwoofer and high pass at 80Hz 2nd order BW (12db/oct) to the main speaker.

3) adjust the delay so your crossover region (80-120Hz) does not have any dips

4) lower the speakers' gain by 4 db to adhere to the harman target curve

5) apply your preferred method of room correction.

Bass management does all of these things automatically, while with a regular MiniDSP you need to do these processes yourself.

 

[fluid]

This is not really a one line subject. "Bass management" as a term refers to how the low frequencies are controlled often in a home cinema setup but also in a music setup, generally where there is more than one subwoofer. The left and right channels can be sent to separate subwoofers placed near the main speakers and there are some (but not many) people who advocate for this setup to preserve separate left and right signals all the way to the lowest frequencies. The majority of people will combine the bass below the crossover frequency into a single monophonic channel and then send this same signal to all the subwoofers. Depending on where the subwoofers are placed in the room will depend on what sort of response they give. In a system where there is control over level, delay, phase and EQ for each subwoofer separately, when combined at the listening position/area the result can be quite flat and even.

There is another option where the main channels if they can produce low enough bass are allowed to run full range without a crossover and the subwoofers only have a low pass filter applied to them. This creates additional bass sources and can help further with smoothing out the spatial variability.

The Dirac MiniDSP solution is not that cheap and will not give the best result possible but it will hold your hand through the process, measurements and fiddling about will still be required.

 

[abdo123]

This is not really a one line subject. "Bass management" as a term refers to how the low frequencies are controlled often in a home cinema setup but also in a music setup, generally where there is more than one subwoofer. The left and right channels can be sent to separate subwoofers placed near the main speakers and there are some (but not many) people who advocate for this setup to preserve separate left and right signals all the way to the lowest frequencies. The majority of people will combine the bass below the crossover frequency into a single monophonic channel and then send this same signal to all the subwoofers. Depending on where the subwoofers are placed in the room will depend on what sort of response they give. In a system where there is control over level, delay, phase and EQ for each subwoofer separately, when combined at the listening position/area the result can be quite flat and even.

There is another option where the main channels if they can produce low enough bass are allowed to run full range without a crossover and the subwoofers only have a low pass filter applied to them. This creates additional bass sources and can help further with smoothing out the spatial variability.

The Dirac MiniDSP solution is not that cheap and will not give the best result possible but it will hold your hand through the process, measurements and fiddling about will still be required.

I would personally not entertain any of these rabbit holes, specially on my first time integrating a subwoofer.

 

[fluid]

Certainly setting up a system properly with multiple subwoofers is not easy even for the experienced. As far as Dirac bass management in the minidsp is concerned all it does is combine all the input channels in to one so any subwoofer setup and tuning is left to the user. I think the OP was hoping for a fully automated setup.

 

[abdo123]

Certainly setting up a system properly with multiple subwoofers is not easy even for the experienced. As far as Dirac bass management in the minidsp is concerned all it does is combine all the input channels in to one so any subwoofer setup and tuning is left to the user. I think the OP was hoping for a fully automated setup.

that's not true, Dirac offers two options 'Upmix only' and 'Full bass optimization'

Full bass optimization will SPL match all the subs and apply crossovers, delays and whatnot.

 

[fluid]

Is that for Dirac in the MiniDSP plugin? The minidsp documents only show downmixing to a single channel for bass management from what I have seen.

 

[abdo123]

that's just the routing matrix.

 

[fluid]

That video refers to a different device and the OP was asking about minidsp devices. Dirac is not quite the same across all platforms. So whilst Dirac itself in some forms has that capability the version in the mindsp does not seem to according to their documents.