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Connect Minidsp HD to Scarlett 6i6 Audio Interfaces
Old 1 week ago
  #31
Gear Nut
 

Quote:
Originally Posted by dinococcus View Post
Assuming the routing possible with the 6i6 (like all pro sound card) : Yes


In short, I will go this way.
From what I understand, the plugins you mention offer the same options as external machines, with the advantage of being free and without the need to make A/D D/A conversions.
There's nothing more to speak of.

Do people opt for external machines for aesthetics? or is it offering something that the plugins you mention can not offer? In that case, do I have something to lose for my purposes?

Another question: Do these programs work regardless of the source of reproduction within the computer? I'd like to do REW sweeps to check the frequency response after setting up the speakers. It's possible?

Thank you.
Old 1 week ago
  #32
Lives for gear
Quote:
Originally Posted by Doclad View Post
In short, I will go this way.
From what I understand, the plugins you mention offer the same options as external machines, with the advantage of being free and without the need to make A/D D/A conversions.
There's nothing more to speak of.

Do people opt for external machines for aesthetics? or is it offering something that the plugins you mention can not offer? In that case, do I have something to lose for my purposes?

Another question: Do these programs work regardless of the source of reproduction within the computer? I'd like to do REW sweeps to check the frequency response after setting up the speakers. It's possible?

Thank you.
The plug-in : yes and all for 0 coast. Except the time alignment (?) crossover and corrrection can do with rephase.

The external gears : avoid a computer crash, standalone work.
I say that but i do not use an external processor. I have only a theorycal knowledge.

If i understand well the last question : yes. You assign in rew the same entry used to enter in the vst host.
Old 1 week ago
  #33
Gear Nut
 

Quote:
Originally Posted by dinococcus View Post
The plug-in : yes and all for 0 coast. Except the time alignment (?) crossover and corrrection can do with rephase.

The external gears : avoid a computer crash, standalone work.
I say that but i do not use an external processor. I have only a theorycal knowledge.

If i understand well the last question : yes. You assign in rew the same entry used to enter in the vst host.
After a lot of patience nd using RTA...I found a good place for subs. The cones of the 4 speakers are the same distance from the listening point. Maybe +/- 1cm. In this case, is it necessary to align the subs temporarily? Intuition tells me no, but I want to be sure.
Old 1 week ago
  #34
Lives for gear
Quote:
Originally Posted by Doclad View Post
After a lot of patience nd using RTA...I found a good place for subs. The cones of the 4 speakers are the same distance from the listening point. Maybe +/- 1cm. In this case, is it necessary to align the subs temporarily? Intuition tells me no, but I want to be sure.
It depends the person.

In your case and in the case of most speakers, it is the tweeter who needs to be align with the woofer.
For the sub, who can the more, can the less and only you after listening could be say.
Old 1 week ago
  #35
Lives for gear
Quote:
Originally Posted by Doclad View Post
In this case, is it necessary to align the subs temporarily? Intuition tells me no, but I want to be sure.
There is a lot of debate about this, here is a pretty good article-

Georg Neumann GmbH - Professional Monitoring

The short version is that A) It is true that as frequency goes down, the threshold of audibility for group delay goes up. However, if you look at those graphs you can see that speakers can have a significant amount as you get to the lowest octaves (especially ported subs). As much as 40ms in those graphs.

Also B) Group delay of a sub is not constant, so if you want to truly correct it, you will not be able to do so with a constant delay value. Instead you need to go to FIR, which is the only process that will be able to fully correct it going low in frequency. That is at the cost of having a relatively high latency playback system.

The typical use of an IIR DSP crossover would be to time align the woofers at the crossover frequency. This at least makes it possible to have them fully in-phase and time aligned at that frequency. This is beneficial particularly for low slope crossovers.
Old 5 days ago
  #36
Gear Nut
 

Hi!!

Here is the .mdat of my little room. 12'x8'x8'.
The measurement is with the satellites and the pair of subwoofers at the same time.

I have the two subwoofer on the sides. I spent an afternoon playing with the phase, the gain and the passive croosover to flatten the frequencies.
SPL chart shows +/-5 to 1/24 smoothing. Considering the dimensions of my room I think it is a very good result.

The impulse seems good with the direct reflexes.
The problem is that I have absorbed the high frequencies too much. All my bass traps have a wooden board in the front, but the side panels, the cloud and the back panels have absorbed everything.
If I want to return life to the room, then impulses appear at -20db -20ms. I guess this is my commitment.
Any suggestions to return a little life? maybe a plugin?
Do you think the room is very dead?

In the spectogram you see a pretty good answer. Even so, there is a peak in 50hz that I could not kill in any way. It is not modal, because my lowest mode is 40hz. I do not know why there is that strange peak.

I would like you to tell me if I have phase problems. For some reason I can not see the Phase in REW.


In short, I am very happy.
Before starting to treatment my room, I listened the music in a 2.1 Logitech €120 placed in any way. The difference has been enormous.

I hope you give me some advice about what I can do to improve.

Thanks!!
Attached Thumbnails
Connect Minidsp HD to Scarlett 6i6-fr-empty-room.jpg   Connect Minidsp HD to Scarlett 6i6-fr-treatment-room.jpg   Connect Minidsp HD to Scarlett 6i6-impulse-treatment-room.jpg   Connect Minidsp HD to Scarlett 6i6-spectogram-empty-room.jpg   Connect Minidsp HD to Scarlett 6i6-spectogram-treatment-room.jpg  

Attached Files
File Type: mdat MyRoom.mdat (6.14 MB, 5 views)
Old 4 days ago
  #37
Lives for gear
 
akebrake's Avatar
 

Quote:
Originally Posted by Doclad View Post
... Considering the dimensions of my room I think it is a very good result...
Congrats! Yes, that's very good!

Quote:
The problem is that I have absorbed the high frequencies too much.
You are experiencing the universal "lack of bass absorption".
Soft absorbers are excellent high, mid and low-mid absorbers. Below 100 Hz the usual thing happens...
(I'll guess your sub woofers goes much lower than 100 Hz)

Quote:
I hope you give me some advice about what I can do to improve
.

All rooms can be improved! What's your budget?


My advice: Make some music in your new room and find out how it works for you.

Then do some tweaking.

Cheers
Old 4 days ago
  #38
Lives for gear
Quote:
Originally Posted by Doclad View Post
I would like you to tell me if I have phase problems. For some reason I can not see the Phase in REW.
Did you have "no timing reference" selected when you took the measurement? If so redo it with "use acoustic timing reference". It's in the dropdown menu under SPL and Impedance buttons at the top of the measurement page. In any case when I opened this in REW 5.20 the phase does show up.

With it unwrapped it goes from about -1100 degrees to about 200 degrees in the measurement which is about 3 and a half rotations. This is a good measurement in a room because it means there are not so many high amplitude early reflections to disrupt the phase response of the speakers themselves. It's debatable rather 3.6 rotations is a problem or not- the only real way to get much lower than this is with FIR correction. With the OpenDRC I can certainly hear a difference between FIR and IIR filter sets, but to be fair it's very difficult to match these so it definitely isn't conclusive that the difference is due to phase correction...


Also the spectrogram you posted is zoomed way out. Here it is with 50ms windowing and a 75ms limit at the top, looking at 20dB. You can see that your sub is late by about 25ms. This is again typical, generally you would be able to align this with the minidsp, and probably use steep slopes to minimize nulling in the crossover region. But again it's debatable how necessary this is.

My opinion, which I find difficult to prove to myself, is that overall phase/impulse correction is subtle but does offer some added tightness/cleanliness. That being said most recordings have a significant amount of *phase damage* from being eq'd in the mixing process...So it's tough to really say this is an area that needs to be fixed.

If you can measure with acoustic timing reference it would still be good to take a peak because the excess group delay box is still greyed out in the GD measurement.
Attached Thumbnails
Connect Minidsp HD to Scarlett 6i6-phase.jpg   Connect Minidsp HD to Scarlett 6i6-spec-75ms.jpg  
Old 4 days ago
  #39
Lives for gear
Quote:
Originally Posted by akebrake View Post
Congrats! Yes, that's very good!
You are experiencing the universal "lack of bass absorption".
Soft absorbers are excellent high, mid and low-mid absorbers. Below 100 Hz the usual thing happens...
(I'll guess your sub woofers goes much lower than 100 Hz)
Looking at these measurements (particularly with no smoothing), it seems he does have a pretty good amount of bass trapping to get this result in a room that is 12'x8'x8'.
Old 4 days ago
  #40
Gear Nut
 

Quote:
Originally Posted by RyanC View Post
Did you have "no timing reference" selected when you took the measurement? If so redo it with "use acoustic timing reference". It's in the dropdown menu under SPL and Impedance buttons at the top of the measurement page. In any case when I opened this in REW 5.20 the phase does show up.

With it unwrapped it goes from about -1100 degrees to about 200 degrees in the measurement which is about 3 and a half rotations. This is a good measurement in a room because it means there are not so many high amplitude early reflections to disrupt the phase response of the speakers themselves. It's debatable rather 3.6 rotations is a problem or not- the only real way to get much lower than this is with FIR correction. With the OpenDRC I can certainly hear a difference between FIR and IIR filter sets, but to be fair it's very difficult to match these so it definitely isn't conclusive that the difference is due to phase correction...


Also the spectrogram you posted is zoomed way out. Here it is with 50ms windowing and a 75ms limit at the top, looking at 20dB. You can see that your sub is late by about 25ms. This is again typical, generally you would be able to align this with the minidsp, and probably use steep slopes to minimize nulling in the crossover region. But again it's debatable how necessary this is.

My opinion, which I find difficult to prove to myself, is that overall phase/impulse correction is subtle but does offer some added tightness/cleanliness. That being said most recordings have a significant amount of *phase damage* from being eq'd in the mixing process...So it's tough to really say this is an area that needs to be fixed.

If you can measure with acoustic timing reference it would still be good to take a peak because the excess group delay box is still greyed out in the GD measurement.
Unfortunately OpenDRC is not an option for me. I have no more budget, I've spent it all on Rockwool hehehe ...
Dinococo suggested using some plugins but they have not worked at all. Rephase does not seem to be able to help me. I think it's just a program to generate corrections but it does not apply the corrections by itself. I am having problems because my native language is Spanish and there is very little information in my language about these topics. On the other hand, I wanted a simple plug-in to do xover with my monitors but both VSThost and the digital DSPs have not worked for me. I'm a little frustrated.

Regarding the phase is a term that escapes me, I do not understand at all how to interpret the graphics. But doing xover should be my priority now.

The .mdat that I have attached is with the 4 speakers playing LF at the same time. It is a headache. If I move a point on the gain knob of some speaker, LF deforms completely, showing valleys from -30db to 60hz. It's very weird. One of the subwoofers is set to 180° phase, I do not know if this has anything to do with this unusual behavior. If you increase the gain from MixControl Focusrite, one of the subwoofers is de-compensated with the other subwoofer and LF deforms. Therefore, I can not change the volume of my system because then I do not get a flat answer. I know it sounds weird, maybe it's just my ignorance.
Another curious thing: If I make a swept at -12db in REW and configure the subwoofers for a flat answer I get what you see in my attachment. But if I make a new measurement at -18db a gigantic valley appears at about 60hz. For some reason the subwoofers are decompensated. I do not understand why.


I can attach a .mdat with this anomaly if you want.

The spectogram:
I did not know that the delay of the subwoofers could be seen from this graph. Thanks for that.
I would like to alienate the monitors with the subwoofers, but evidently doing xover is the priority at this moment.
Old 4 days ago
  #41
Gear Nut
 

Quote:
Originally Posted by RyanC View Post
Looking at these measurements (particularly with no smoothing), it seems he does have a pretty good amount of bass trapping to get this result in a room that is 12'x8'x8'.
Yes, the room is very small.

I have rectangular soffits of 20" deep behind the speakers (bye bye SBIR) and the back wall is almost completely absorbed with a cotton sofa, 10" thick panels for early reflections and 18" traps in a corner and the the ceiling.

No doubt there is a compromise here: Kill the room and have ETC clean of early reflections, or cover with reflective panels to have life but an ETC that is ugly below -20db/-20ms. Up until this moment I had not understood how useful diffusion can be. Unfortunately in such a small room it does not seem to be an option.

I only try to follow the advice of the professionals in this forum.
Old 3 days ago
  #42
Lives for gear
Quote:
Originally Posted by Doclad View Post
Unfortunately OpenDRC is not an option for me. I have no more budget, I've spent it all on Rockwool hehehe ....
Well, that is a good choice! Money well spent-

You are correct about rephase, it doesn't do anything on it's own.

For the rest of the issues you describe, you are saying you can't change volume from the 6i6 and maintain the same response? That is weird...to me it seems like maybe an impedance issue, are you using Y cables to get to the subs and speakers? Something is changing the balance between subs with a change in input it seems.

It certainly is nice to have DSP control with subs. If it we me, I would save the extra 150 for the opendrc, but it does sound like the 2x4 hd or similar might still benefit you. I would email minidsp first and ask for the latency if that matters to you, their products are all over the map.

One option to restore life to a small dead room, without ruining it with ERs, is to add some rear speakers, delay them so they arrive at the listening position ~25ms later than the source and add subtle, short, diffused reverb and mix them in ~15dB or so below the primary speakers. The OpenDRC can actually load convolution reverb impulses (so says the manual, I haven't tried it yet or figured out how to get the correct format)...If you want to experiment with that you don't need very high quality rear speakers, but your crossover will need the extra outputs (6 in your case it sounds like).

From my experiments with this I liked it enough that I am designing my new commercial studio build around it (so it can be switched on and off). There are a lot of variables to play with because the ambient speakers can be positioned to illuminate diffusers/slats/reflective surfaces while the primary speakers can be positioned to minimize ERs. Also if you have multiple listening positions you can position the ambient speakers above a ceiling cloud (this is what I will be doing). Something to think about at least...
Old 3 days ago
  #43
Gear Nut
 

Quote:
Originally Posted by RyanC View Post
Well, that is a good choice! Money well spent-

You are correct about rephase, it doesn't do anything on it's own.

For the rest of the issues you describe, you are saying you can't change volume from the 6i6 and maintain the same response? That is weird...to me it seems like maybe an impedance issue, are you using Y cables to get to the subs and speakers? Something is changing the balance between subs with a change in input it seems.
Ryan

I can not find the impedance of the Samson subwoofer. In case they have different impedances...do you mean that everything is lost?
Old 3 days ago
  #44
Gear Nut
 

Well, you can see the problem in the .mdat file. When I set the subwoofers for a flat response I can only do it at a certain gain. The Samson subwoofer is not sensitive to the difference of -6db / -12db. Samson has a general volume knob and a volume knob for the subwoofer. I suppose it is used when you connect the network to your xover.

Is it a poorly designed subwoofer, or is there something I do not understand and this has some solution?

Thank you
Attached Thumbnails
Connect Minidsp HD to Scarlett 6i6-descarga.jpg  
Attached Files
File Type: mdat subwoofer measurements.mdat (796.1 KB, 2 views)
Old 3 days ago
  #45
Gear Nut
 

I just did another test with Samson.

It is sensitive to the difference of -18dbfs / -12dbfs. But not to the difference of -12dbfs / -6dbfs.

What does this mean?
I am perplexed.
Attached Files
File Type: mdat Samson.mdat (402.8 KB, 3 views)
Old 3 days ago
  #46
Lives for gear
Quote:
Originally Posted by Doclad View Post
I just did another test with Samson.

It is sensitive to the difference of -18dbfs / -12dbfs. But not to the difference of -12dbfs / -6dbfs.

What does this mean?
I am perplexed.
Interesting. It might have some sort of limiter...
Old 3 days ago
  #47
Gear Nut
 

Quote:
Originally Posted by RyanC View Post
Interesting. It might have some sort of limiter...
Yes, you have hit. The general sound controller of the SAMSON sub must be halfway.

I have already adjusted the subwoofers.

Attached Files
File Type: mdat samson + yamaha.mdat (658.4 KB, 1 views)
Old 2 days ago
  #48
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