panteragstk

panteragstk

Audioholic Warlord
HA!

beard·y
ˈbirdē/
adjective
informalderogatory
adjective: beardy; comparative adjective: beardier; superlative adjective: beardiest; adjective: beardie
  1. 1.
    (of a man) having a beard.
    "in the year of beardy hipsters, he looks nearly a decade out of fashion"
noun
noun: beardie; plural noun: beardies; noun: beardy
  1. 1.
    BRITISHinformalderogatory
    a bearded man, especially one regarded as lacking in style.
    "the cartoons show him as a mad beardie"
  2. 2.
    informal
    a bearded collie.
    "expect to be greeted with a bounce when you meet a beardie"
 
Mitchibo

Mitchibo

Audioholic
This one looks pretty good. Looks like you have a nice house curve going there. A little peak at about 45hz and a saddle between 50 and 90hz.
View attachment 22064
You're getting much better extension with your deeper bass now. You have to be able to hear it too. I'm just learning here, but I'd try putting a +3db low shelf filter on there and see what it does. I'm getting a little bit deeper bass than my subs are spec'd in my room. If your subs are good to 24 hz you might be able to get it down close to 20.

Before doing that though, I'd consider moving stuff around a little and see how smooth you can get with just placement first. Do a control sweep with no eq, no Audyssey or filters at all, then see if moving things around, even a few inches either way, makes any improvements. Take another sweep after every adjustment and compare.

One big factor for me was getting my speakers a little further from the walls and moving my subs closer together. That made some improvements by itself. Then I didn't have to do as much with the mini, which made things easier for Audyssey.
I tried pushing the low shelf around in the lower frequencies to no useful outcome. Next I'll try placement options. I also have the option of grouping them in two's and using the other sub output on the AVR. That might make setting up the mini more complex but Audyssey will calibrate up to two subs individually.

Time consuming.
 
Mitchibo

Mitchibo

Audioholic
Be careful, those subs simply are not designed to play low. Boosting at and below resonance of the woofer is a great way to over work the driver and produce that 'one note bass' symptom. Think car audio, BOOM BOOM. Loud? Hell yeah! Accurate? Not a chance!
No doubt. Not a fan of Boom-Boom. I think I'm safe though.
 
Pogre

Pogre

Audioholic Slumlord
I tried pushing the low shelf around in the lower frequencies to no useful outcome. Next I'll try placement options. I also have the option of grouping them in two's and using the other sub output on the AVR. That might make setting up the mini more complex but Audyssey will calibrate up to two subs individually.

Time consuming.
It is time consuming and a little tedious sometimes. I spent a fair amount of time nudging things around and doing sweeps. Try everything. You never know what might work best.
 
ATLAudio

ATLAudio

Senior Audioholic
@Mitchibo

Get your subs corner positioned if you can. Then use MiniDSP to get a flat response. It looks like you have a broad bump peaking at around 50hz. Try a -3dB Q = 3 peak filter.

Once you get it flat, run Audyssey and let me know what you think.

What kind of room is this? Size?
 
panteragstk

panteragstk

Audioholic Warlord
@Mitchibo

Get your subs corner positioned if you can. Then use MiniDSP to get a flat response. It looks like you have a broad bump peaking at around 50hz. Try a -3dB Q = 3 peak filter.

Once you get it flat, run Audyssey and let me know what you think.

What kind of room is this? Size?
I was going to ask this as well. @Mitchibo have you plugged your room dimensions into REW and positioned your subs according to the MLP? I did that and it totally changed my plan in my theater. Corner loading all 4 was by far the best thing I could do to flatten my room mode.
 
William Lemmerhirt

William Lemmerhirt

Audioholic Overlord
No doubt. Not a fan of Boom-Boom. I think I'm safe though.
Agreed. I'm pretty sure nobody is saying to boost what isn't there as far as LF response. I think the idea(for me anyway) is to let the subs play as low as they can naturally(without chopping off the LF signal), and pull down the peaks to level the response out. A bell shaped curve would no doubt sound boomy, and one note-ish.
 
Mitchibo

Mitchibo

Audioholic
@Mitchibo

Get your subs corner positioned if you can. Then use MiniDSP to get a flat response. It looks like you have a broad bump peaking at around 50hz. Try a -3dB Q = 3 peak filter.

Once you get it flat, run Audyssey and let me know what you think.

What kind of room is this? Size?
Three of the four are corner loaded, one is partially backed up to wall that opens to another room. I've pulled and peaked all available Db out from 40-50 hz where the bump was the worst. This is as flat as I can get it w/the mini and my knowledge of said device. Now it's on to placement measurements.

The room is 20ft wide x 14ft length x 8 ft ceiling.
 
Mitchibo

Mitchibo

Audioholic
I was going to ask this as well. @Mitchibo have you plugged your room dimensions into REW and positioned your subs according to the MLP? I did that and it totally changed my plan in my theater. Corner loading all 4 was by far the best thing I could do to flatten my room mode.
I did see "modal analysis" in the EQ tab. I haven't messed with this at all other than viewing the settings. I need to do a little refresh reading on this. Thanks.
 
panteragstk

panteragstk

Audioholic Warlord
I did see "modal analysis" in the EQ tab. I haven't messed with this at all other than viewing the settings. I need to do a little refresh reading on this. Thanks.
The room simulator is a great tool to essentially do a "sub crawl" for you or at least make it easier. It opened my eyes for sure.
 
TheWarrior

TheWarrior

Audioholic Ninja
Three of the four are corner loaded, one is partially backed up to wall that opens to another room. I've pulled and peaked all available Db out from 40-50 hz where the bump was the worst. This is as flat as I can get it w/the mini and my knowledge of said device. Now it's on to placement measurements.

The room is 20ft wide x 14ft length x 8 ft ceiling.
I've not yet seen anyone list the filters that they've plugged in to a minidsp. So if you wanted to break that trend, great! Don't need a pic, just type out Frequency-Q-Gain-Type

56 hz, 81 hz, 141 hz (rounded) would be the predicted modes. They are predictions, because rooms have doors and windows which allow the boundaries to flex, lowering the actual. So it needs to be clearly understood exactly what you've already plugged in to the minidsp, to which channel as it effects the measurements you posted. Additionally, do you have multiple couches, or arm chairs? Pillows? Heavy drapes?

Which wall holds the TV? Where are any doorways/windows in relation to that wall? What is the distance from that wall to the Listening Position? How close are the subs to the corners? In order to destructively drive that 20' length mode with 4 subs, knowing the position of the listeners in the room is crucial to applying the correct filters to the correct subs.

The measurement you posted had the first mode centered at 45 hz (20' wall), and is wide enough to stretch 40-50 hz (maybe a tad more), which is a Q (bandwidth) of 11. I don't think these measurements are 1/24 octave so I would recommend taking another measurement, with the speakers to at least 500 hz so we can clearly see the actual modal frequency because it can sharply change the measured Q and Gain of those modes. Seeing higher order modes (by measuring up to or above 500 hz) also helps determine the effectiveness of any filters added based on the attenuation of those modes.
 
ATLAudio

ATLAudio

Senior Audioholic
Three of the four are corner loaded, one is partially backed up to wall that opens to another room. I've pulled and peaked all available Db out from 40-50 hz where the bump was the worst. This is as flat as I can get it w/the mini and my knowledge of said device. Now it's on to placement measurements.

The room is 20ft wide x 14ft length x 8 ft ceiling.
Placement measurements? I don't follow. Do you have a new sweep you can post for where you're at so far?
 
Mitchibo

Mitchibo

Audioholic
Placement measurements? I don't follow. Do you have a new sweep you can post for where you're at so far?
I meant placement of subs. I have some room to reposition them and then take comparative measurements. I need to do that to remove as much placement bias as I can. Measurements to follow.
 
panteragstk

panteragstk

Audioholic Warlord
I meant placement of subs. I have some room to reposition them and then take comparative measurements. I need to do that to remove as much placement bias as I can. Measurements to follow.
I think if you're corner loaded that is usually one of the best places. I know that in my room a sub in all four corners canceled my room mode of 40hz. I'll find out when I actually get everything installed in the next few weeks.
 
William Lemmerhirt

William Lemmerhirt

Audioholic Overlord
I think if you're corner loaded that is usually one of the best places. I know that in my room a sub in all four corners canceled my room mode of 40hz. I'll find out when I actually get everything installed in the next few weeks.
Probably because corner loading excites all the room modes at once more evenly.
 
ATLAudio

ATLAudio

Senior Audioholic
I meant placement of subs. I have some room to reposition them and then take comparative measurements. I need to do that to remove as much placement bias as I can. Measurements to follow.
Great idea, let us know what you come up with.
 
TheWarrior

TheWarrior

Audioholic Ninja
I meant placement of subs. I have some room to reposition them and then take comparative measurements. I need to do that to remove as much placement bias as I can. Measurements to follow.
Your ears are a perfectly decent measurement instrument for that. The front towers should be set wide enough and toed in enough to achieve a 'phantom center' and control the precedence effect (it explains why two ears hear one sound from two speakers, when the effect breaks down by improper placement, you hear each speaker separately) at all listening positions. An omni mic won't be able to tell you that!


Mark Seaton Subwoofer Calibration Steps

I found this very useful. It's not dogma, and but I've tried all steps and kept what worked for me.

Correct, it's not dogma, it's guesswork. To assume you can look at a measurement and understand why it measured that way is a terrible mistake. Flat, is never the goal, only accurate. There have been far too many posts on this forum about applying DSP filters to achieve a visual effect in a measurement (flat) without taking any time to understand why the system measures in such a way. I ONLY recommend applying filters based on room mode measurements. You match a DSP filter's amplitude, Q and frequency to the frequency centered in a peak or null of a mode. Trying to boost subs below the influence of room modes can be detrimental to higher frequencies and is yet another cause of 'one note bass' issues. Failure to achieve desired low bass means more or more capable subs are needed.

It can be a good bit of work. But once it's done, it's done!


56 hz, 81 hz, 141 hz (rounded) would be the predicted modes. They are predictions, because rooms have doors and windows which allow the boundaries to flex, lowering the actual. So it needs to be clearly understood exactly what you've already plugged in to the minidsp, to which channel as it effects the measurements you posted. Additionally, do you have multiple couches, or arm chairs? Pillows? Heavy drapes?

Which wall holds the TV? Where are any doorways/windows in relation to that wall? What is the distance from that wall to the Listening Position? How close are the subs to the corners? In order to destructively drive that 20' length mode with 4 subs, knowing the position of the listeners in the room is crucial to applying the correct filters to the correct subs.

The measurement you posted had the first mode centered at 45 hz (20' wall), and is wide enough to stretch 40-50 hz (maybe a tad more), which is a Q (bandwidth) of 11. I don't think these measurements are 1/24 octave so I would recommend taking another measurement, with the speakers to at least 500 hz so we can clearly see the actual modal frequency because it can sharply change the measured Q and Gain of those modes. Seeing higher order modes (by measuring up to or above 500 hz) also helps determine the effectiveness of any filters added based on the attenuation of those modes.

I hope you give this a try!
 
ATLAudio

ATLAudio

Senior Audioholic
@TheWarrior

“Correct, it's not dogma, it's guesswork.”

I’m comfortable in my opinion that it’s based on far more than guesswork.

“To assume you can look at a measurement and understand why it measured that way is a terrible mistake.”

Define “terrible mistake.” Below the transition frequency of the room, the room controls bass response. There are varieties of tools which allow one to properly correct them. This list is fairly comprehensive in detailing them.

“Flat, is never the goal, only accurate. There have been far too many posts on this forum about applying DSP filters to achieve a visual effect in a measurement (flat) without taking any time to understand why the system measures in such a way.”

Where does it say in this link that “just flat” was the end goal? While flat response is indeed accurate, preference can be anything. Steps 9-16 reflect this.

“I ONLY recommend applying filters based on room mode measurements.”

I ONLY disagree! I found that I have to go past simply knowing room modes and ONLY filtering them to get the response which I prefer. You do it your way, but this is what worked for me, so I pass it on. If you did it this way and it didn’t work for you, that’s also fine. But, do you have a concise detailed list which DID work for you? Please share!

“You match a DSP filter's amplitude, Q and frequency to the frequency centered in a peak or null of a mode.”

Right, most of us know how to use REW.

“Trying to boost subs below the influence of room modes can be detrimental to higher frequencies and is yet another cause of 'one note bass' issues.”

Boosting, cutting, or leaving response alone, to the preference of the listener, leads to a satisfied listener. What you might think is one note car bass (ad hom) might be audio ambrosia to another. If you don’t want to boost any particular arbitrary aspect of your response, and that approach works for you, by all means do it that way. I’m comfortable letting the listener decide what sounds good or not, and to boost, cut accordingly. This is also reflected in steps 9-15.

“Failure to achieve desired low bass means more or more capable subs are needed.”

Sometimes, but certainly not always. The satisfaction many here have had using REW/MiniDSP, suggests otherwise.

“It can be a good bit of work. But once it's done, it's done!”

Figuring out your room modes is fairly easy, but it’s tertiary information by itself. REW can even calculate them into a curve for you (YMMV). In any event it’s usually apparent when you do your first sweep. Finding proper location for your subs takes a lot of this out of the question in the first place. I’ll be honest, I think you’re on a massive Dunning Kruger kick and are simply too quick to condescend to ideas if they don’t absolutely reflect your own.
 

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