Have been experimenting with Room EQ

IWC Dopplel

Distinguished Member
When I pick one up I should be able to check the alignment as at the moment I am adding a front channel to the 2x4 and I have EQ'd L,R in combination with the delays for the sub group which shows alignment at 40 Hz, I can check the centre as well when its connected. I have the ability to add delays to each channel in the Panasonic and I can check the alignment with the sub foreach channel. I guess all you can do is align at one frequency and one position in any case ?
 

Conrad

Moderator
No, that's the point, you're not aligning anything. The all pass changes the phase response independently of the impulse response, I think.

If you align center and subs, and then change the delay on L to better align with the subs you'll get a mismatch between L and C and pans will sound weird and you'll likely get cancellations between L and C (although they'll both sound good with the subs, but only individually).

The All Pass filter allows you to change the phase without changing the timing. I think.

These are the articles I was shown:

I haven't tried it, but I know a man that has, I'll see if I can get him to comment. He's using 88s though, not 10x10s.

This is the approach that DBLC uses I believe. As I say, I'm expecting Trinnov to implement it in their next firmware. I heard that they're working on improved bass management, which makes sense given the advances that Dirac have made.
 

Conrad

Moderator
When I pick one up I should be able to check the alignment as at the moment I am adding a front channel to the 2x4 and I have EQ'd L,R in combination with the delays for the sub group which shows alignment at 40 Hz, I can check the centre as well when its connected. I have the ability to add delays to each channel in the Panasonic and I can check the alignment with the sub foreach channel. I guess all you can do is align at one frequency and one position in any case ?
Also, the approach isn't to align the phase at the crossover frequency, necessarily, it's to ensure the smoothest response through the crossover range. I don't know if that's what you meant by "alignment at 40Hz".
 

IWC Dopplel

Distinguished Member
I think 🤔 when you have two speakers at different locations they will only align at one location and one frequency, so you typically choose the xover when integrating ?
 

Conrad

Moderator
I'm going to rope in @AndreNewman now as he's doing something similar to you and knows more about it, I'm educated-guessing based on limited theoretical knowledge.
 

AndreNewman

Active Member
I'm working towards doing the MSO satellite optimisation that Conrad linked to but I'm not there yet.

So far I have a DDRC-88A and a DDRC-24 doing 5.1.4 with two subs.

The DDRC-24 does center and LFE withing timing and EQ for two subs with bass management in the AVR before the Minidsps and the DDRC-88A does the remaining channels.

I've got as far as a conventional subs only MSO optimisation and Dirac over the top of that. I found that Dirac was interacting with my MSO EQs and I'm currently a/b ing between the MSO only, MSO+Dirac full range 15-200Hz and MSO+Dirac curtains at 55-200Hz. the latter is the best measuring but not really the best sounding, so far.

The Satellite optimisation thing using MSO is intriguing because as I understand it has a lot in common with Dirac's DLBC. There has been some issues with DLBC and the Level 2 fix that is one of the fixes being beta tested, on paper, looks a lot like what MSO can do with a bunch of Minidsps, interesting.

So the key thing with the MSO satellite optimisation is that it must have corresponding all pass filters in all channels to work. If you miss out a channel that channel will have a terrible crossover that I believe will be unfixable.

I originally had 7.1 through the DDRC-88A and my 4 atmos speakers on the AVR directly, this sounds pretty good but doesn't allow me to try the MSO thing. So I upgraded my minidsp 2x4 to DDRC-24 and this is where I am.

I was never good as the maths side of Electronics at college but I understand that an all pass filter allows phase to be varied around a center frequency without affecting amplitude. So MSO will adjust these all pass filters in pairs for L&R compared to the LFE+BM channel and then separately for SL&SR with LFE+BM then TFL&TFR and LFE+BM etc. etc. the end result being around the crossover frequency the phase of all of the satellite speakers will be in phase with the subwoofers LFE+BM channel. Usually we get the best crossover when the subs and satellites are in phase throughout the crossover region.

The LFE channel is optimised first as a conventional MSO subs run, then the all pass is added. Then each individual pair is measured and optimised to the sub, pair by pair.

As Andy says in the docs, tedious.
 

MI55ION

Distinguished Member
Looking at the DDRC-88A and trying to get my head around it.

What's does the 88BM plugin offer that isn't included with the 88A? Is it just a multi-channel version of the control UI that comes with a regular 2x4HD? Is it necessary when using DIRAC software or it just allows for greater flexibility?
 

AndreNewman

Active Member
Looking at the DDRC-88A and trying to get my head around it.
Yeah, it confused me until I sat down with an 88A in front of me.
What's does the 88BM plugin offer that isn't included with the 88A? Is it just a multi-channel version of the control UI that comes with a regular 2x4HD? Is it necessary when using DIRAC software or it just allows for greater flexibility?
If you have the plain 88A you don't get any control UI beyond setting channel groups/zones, master volume and launching Dirac Live.

I was coming from the 2x4HD and expecting at least similar features with an optional addon bass management thingy. I wondered what was so amazing about the BM that they sold it separately, now I know.

In reality the bass management is actually bass management, peq, timing, matrix, crossovers, biquads, everything. So the BM addon is actually better value but the plain 88A is less so, it's "just" an 8 channel Dirac box, absolutely nothing else.

So for Dirac you don't need the BM plugin, it's the same software, same UI but almost everything is greyed out, you do everything in Dirac. I don't have the BM and my Dirac is fine.

I'm doing my subs on a DDRC-24 so I get all the peq, timing etc that I had when it was a 2x4HD. the only thing that disappears when you do the Dirac update is the IIR feature.

I believe the BM update for 88A does pretty much the same as the 2x4HD but with 8 Channels, you can flick through the UI and see what's there before you connect to the 88A. As soon as you connect, the UI greys out, I thought mine was broken when I first got it home...
 

MI55ION

Distinguished Member
Thanks a bunch for that, I've had to go over it a couple times! So for a simpleton like me, if you purchased the 88A with Dirac, you simply don't need the BM, is that correct? Do you still have control of those functions (BM) for user adjustment?
 

AndreNewman

Active Member
Thanks a bunch for that, I've had to go over it a couple times! So for a simpleton like me, if you purchased the 88A with Dirac, you simply don't need the BM, is that correct?
Yes, don't need the BM addon for Dirac, I don't have it.

Do you still have control of those functions (BM) for user adjustment?
Nope, you have to do BM in the AVR or processor before the 88A sees it.

There's no BM or crossover functionality in the Dirac that works on the 88A, you still have to do sub timing, distance tweak, whatever in your AVR or another DSP.

It works with Dirac 3, I have 3.0.14 but the 88A doesn't have what's needed to use the new DLBC addon for Dirac, not at any level. You tell the 88A which is LFE but it does absolutely nothing with the information, maybe it just stops Dirac panicking that the speaker didn't do anything higher than 300Hz! Actually it's not even that because the DDRC-24 doesn't have that bit and I'm using it for LFE.

What channels are you planning to push through the 88A? If you want to push LFE through the 88A and connect multiple subs to it then you would probably want the BM licence, if you are doing LFE separately like I am you don't need it.

Hope that helps.
 

MI55ION

Distinguished Member
I was planning on using the 88A to primarily EQ (Dirac) all 7.1 channels. The .1 channel would then feed a 2x4HD for multi-sub control, BEQ etc.

Somthing I don't get is what does DLBC offer that isn't already available within the 88A's Dirac based correction? Also is the 88A hardware limited to take advantage of DLBC?

Sorry to be a pain, I really need to visit the relevant AVS thread and start from the beginning. :confused:
 

AndreNewman

Active Member
I was planning on using the 88A to primarily EQ (Dirac) all 7.1 channels. The .1 channel would then feed a 2x4HD for multi-sub control, BEQ etc.
Ah ok, I had that exact setup when I first got the 88A, works well.

Do the subs stuff on 2x4HD first, then do the Dirac on the 88A, then fine tune the over all delay on the 2x4HD for crossovers after Dirac has been at it.
Somthing I don't get is what does DLBC offer that isn't already available within the 88A's Dirac based correction?
Lots;
It allows you to adjust crossovers in Dirac, see how it affects the signal.
With the extra levels
It will independently eq the sub, (or subs with the extra extra licence) for seat to seat response.
It will phase all the crossovers to match up with the subs.

You can do some (maybe all) of the above with REW and MSO but this is manual, tedious, complicated and (as I'm finding) sometimes Dirac will fight you along the way.
Also is the 88A hardware limited to take advantage of DLBC?
There's no DLBC possible on the 88A, Minidsp don't (yet?) make anything that can do DLBC.
Sorry to be a pain, I really need to visit the relevant AVS thread and start from the beginning. :confused:
No worries, I went through all the same stuff.

I would say that you want to be comfortable with how to do all this stuff before jumping in with the 88A, there's a lot to do and a lot of futzing about needed and that's after you've understood it all.

I got a two week old DDRC-88A from someone who seemed to want it all done for him in a hour or two with a fancy interface. I like the clear technical interface that minidsp provide, I don't want a warm and fuzzy interface that hides everything but that's not for everyone.

I suspect that I will be selling on my Minidsp stuff in a year or two and getting a HTP-1 so I can take advantage of DLBC, simplify things and get a lower noise floor. For now I'm using the Minidsp as a cheap way to find out if I like Dirac, if it fixes the remaining issues in my room (I do and it mostly does).

With the noise floor comment, I can hear a faint hiss on all my channels if I listen next to the tweeter. That was not there until I put the 88A & 24 in circuit, I have only 12dB headroom in the minidsp so that's probably as good as it gets. The improvement I get from Dirac is worth the low level hiss, for the money.
 

MI55ION

Distinguished Member
Ah ok, I had that exact setup when I first got the 88A, works well.

Do the subs stuff on 2x4HD first, then do the Dirac on the 88A, then fine tune the over all delay on the 2x4HD for crossovers after Dirac has been at it.

Lots;
It allows you to adjust crossovers in Dirac, see how it affects the signal.
With the extra levels
It will independently eq the sub, (or subs with the extra extra licence) for seat to seat response.
It will phase all the crossovers to match up with the subs.

You can do some (maybe all) of the above with REW and MSO but this is manual, tedious, complicated and (as I'm finding) sometimes Dirac will fight you along the way.

There's no DLBC possible on the 88A, Minidsp don't (yet?) make anything that can do DLBC.

No worries, I went through all the same stuff.

I would say that you want to be comfortable with how to do all this stuff before jumping in with the 88A, there's a lot to do and a lot of futzing about needed and that's after you've understood it all.

I got a two week old DDRC-88A from someone who seemed to want it all done for him in a hour or two with a fancy interface. I like the clear technical interface that minidsp provide, I don't want a warm and fuzzy interface that hides everything but that's not for everyone.

I suspect that I will be selling on my Minidsp stuff in a year or two and getting a HTP-1 so I can take advantage of DLBC, simplify things and get a lower noise floor. For now I'm using the Minidsp as a cheap way to find out if I like Dirac, if it fixes the remaining issues in my room (I do and it mostly does).

With the noise floor comment, I can hear a faint hiss on all my channels if I listen next to the tweeter. That was not there until I put the 88A & 24 in circuit, I have only 12dB headroom in the minidsp so that's probably as good as it gets. The improvement I get from Dirac is worth the low level hiss, for the money.

Thanks @AndreNewman, you've broken it down perfectly and saved me hours of searching. :smashin:

I'm thinking of it as a stopgap solution like yourself but I've also reached the limits of tweakability in my current system/room and would actually like the challenge of taking on something new and the learning process it involves. From what you've said sounds like exactly what I'd want.

My only reservation at the moment, I place an order for one and a couple months down the line Minidsp announce a new unit with everything the 88A has to offer plus DLBC. Sort of a fear that I might be getting something toward the end of its shelf life.
 

AndreNewman

Active Member
Thanks @AndreNewman, you've broken it down perfectly and saved me hours of searching. :smashin:
No worries.
I'm thinking of it as a stopgap solution like yourself but I've also reached the limits of tweakability in my current system/room and would actually like the challenge of taking on something new and the learning process it involves. From what you've said sounds like exactly what I'd want.
That's where I was.

My only reservation at the moment, I place an order for one and a couple months down the line Minidsp announce a new unit with everything the 88A has to offer plus DLBC. Sort of a fear that I might be getting something toward the end of its shelf life.
See my post on AVS :rolleyes:

This is why I bought a second hand 88A


#18,135

So now Minidsp can announce their new 16 channel processor, Monolith can announce UK sales of the HTP-1, Dirac can make a general release of the DLBC fixes and Onkyo, Integra, Pioneer can mailshot me about their Dirac models available next week :rolleyes:
 

MI55ION

Distinguished Member
Well I wouldn't be interested in any of those except the (imaginary) minidsp and the elusive htp-1. Suppose it should make the decision easier for me. :D
 

AndreNewman

Active Member
Well I wouldn't be interested in any of those except the (imaginary) minidsp and the elusive htp-1. Suppose it should make the decision easier for me. :D
Well now I've bothered to get amplifiers for all channels I guess I'm only interested in the HTP-1 or something similar that minidsp might theoretically produce. They did mutter something about a replacement worth waiting for when they discontinued the nanoavr but that's been a while now.
 

AndreNewman

Active Member
Hope you got XLR inputs, I hear issues of popping with RCA.
I don't, this was one of the reasons I didn't order a HTP-1 from the US and hope it didn't ever need to go back.

I would have to modify all my amps to have proper balanced inputs, most of them have XLR but they aren't balanced.

I have to say, I have faint popping from the 88A when playback starts or stops!
 

Topmetom 2

Distinguished Member
No worries.

That's where I was.


See my post on AVS :rolleyes:

This is why I bought a second hand 88A


#18,135

So now Minidsp can announce their new 16 channel processor, Monolith can announce UK sales of the HTP-1, Dirac can make a general release of the DLBC fixes and Onkyo, Integra, Pioneer can mailshot me about their Dirac models available next week :rolleyes:
Id be interested in anything that runs dirac and isnt as bugged up as starship troopers tbh
 

AndreNewman

Active Member
Id be interested in anything that runs dirac and isnt as bugged up as starship troopers tbh
Well yes...

That seems to be a difficult thing to achieve.

I went for the Minidsp as my Yamaha AVR works, doesn't crash, doesn't make siren noises, decodes all the formats I need to all the speaker layouts I need, doesn't overheat (especially now it doesn't have any speakers connected) I can leave it on Dolby Surround and it always decodes or upmixes to the best format it's fed, no dramas.

I don't think it's possible to say that about ANY of the current Dirac processors or AVRs at any price.

I followed the:
NAD Threads until it became apparent that current NAD will never have DLBC.
Arcam Threads, they have few bugs now but attitude to fixing seems bad, not clear what was hardware bugs and what was software. They have just posted an update for the older AVRs so maybe they are changing their ways.
Monolith HTP-1 Threads, was very buggy but very good attitude to fixing stuff, still have some issues, quite clear what is hardware and what is software.

I will follow the Onkyo,Integra,Pioneer AVRs as they become available, I suspect it will be a mess at launch and the financial issues behind all this make me wonder if they have the backing to fix bugs for the future.

Likely outcome will be buying a HTP-1 in a year or two, when they have an audio board that outputs unbalanced properly (non AKM DACs I expect) and maybe a HDMI 2.1 video board but I have a Vertex2 so I'm not bothered about that. Oh and when they sort out their controller board that craps out on a power outage! A UK dealer would be good too, although the price will probably shoot up if they do that.
 

IWC Dopplel

Distinguished Member
My solution which I will start next month is to EQ the subs as a group, integrate the timing with other channels using processor and/or the Mini DSP 10x10. I will only EQ the bass using 8 analogue channel in and three out to the subs. at the moment I am doing this successfully with a 2x4 HD with the appropriate setting in to EQ and align the subs as a group (lots off REW and experimentation). I want to leave all speakers full range and just fill in the missing bass using the 10x10 HS which for me will be 8in (7 just the same feed that is going to each channel direct in parallel) 3 subs out. As I am only 7.3.0

I know I can do this as I have successfully added the fronts via a second feed in to the sub group then filter the input so I remove some of the request to the subs where the mains are not needing augmentation (2x4, is LFE,mains in, additional EQ on the mains in, no additional EQ on the LFE in and the same EQ on the subs out)

So much more manual and only 8 channels
 

MI55ION

Distinguished Member
Whilst browsing the Dirac site, came across something called Dirac Live Desktop and had a light bulb moment, might not even need a miniDSP. So I've installed the 14 day trial on my desktop 2.1 system, currently comparing it back to back against what I was able to achieve with JRiver EQ.

Next step will be to install it on my HTPC in the main system and if it a) plays nice/ is compatibe, and b) sounds good, then I might have just come across a solution. Other than the software license, there's no added expense or AD/DA conversion steps necessary. Would be interested to hear from anyone who might have walked this road already.
 

AndreNewman

Active Member
My solution which I will start next month is to EQ the subs as a group, integrate the timing with other channels using processor and/or the Mini DSP 10x10. I will only EQ the bass using 8 analogue channel in and three out to the subs. at the moment I am doing this successfully with a 2x4 HD with the appropriate setting in to EQ and align the subs as a group (lots off REW and experimentation). I want to leave all speakers full range and just fill in the missing bass using the 10x10 HS which for me will be 8in (7 just the same feed that is going to each channel direct in parallel) 3 subs out. As I am only 7.3.0

I know I can do this as I have successfully added the fronts via a second feed in to the sub group then filter the input so I remove some of the request to the subs where the mains are not needing augmentation (2x4, is LFE,mains in, additional EQ on the mains in, no additional EQ on the LFE in and the same EQ on the subs out)

So much more manual and only 8 channels
So like double bass, crossover to subs but bass goes to full range speakers as well?
Or more like very low frequency crossover?

Maybe the MSO satellite alignment thing would have a big effect on how well that works as all channels would need to be in phase for the whole frequency range that the subs and mains overlap for. I know the all pass filters can do that for a range around the crossover frequency, maybe that range can just be widened.

I'd love to see MSO chewing on that measurement set!
 

AndreNewman

Active Member
Whilst browsing the Dirac site, came across something called Dirac Live Desktop and had a light bulb moment, might not even need a miniDSP. So I've installed the 14 day trial on my desktop 2.1 system, currently comparing it back to back against what I was able to achieve with JRiver EQ.
I was considering that to see if I liked Dirac, problem for me is it can only handle 8 channels. Even if it could do more there's no way to get them to the atmos speakers.

The other issue is I hate the JRiver user interface...
 

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