Low frequency issues and measurements

[atoprak]

Dear all,

Last week I have created another topic about the null area right on my listening position and how to fix that.
As I also believe in science and measurements I ordered Umik-1, taken some measurements before investing (or may be not investing at all ) for DSP or even another sub.

Here is my first measurements.
Keep in mind that this is my first measurement with Umik-1 (with any mic actually) and just followed tutorial from a nice guy on YouTube

As it is recommended, I have taken several measurements from different listening positions and also some measurements without subwoofer

I have a pair of Monitor Audio Rx6 and a BK XLX200Mk2 subwoofer (I believe the rest shouldn't have an effect for that measurements.... oh may be cables... joking )
My sub is rolled off around 90 hz and has a 90 degree phase as of now... these are all subject to change ... and by the way, the mesh grills of the speakers and the sub was on ... I am hearing significant change when I put them away at high frequencies (but not the subject for now )

My ideal listening position with sub.

My ideal listening position without sub

Subwoofer alone

and also with sub and without

Question ...
Is the patient dead or can be survived with my a better sub with bit more features or bit better placement) as replacement .. or a DAP can help me a bit about anything ... or is it necessary (must may be ) to buy a second sub... ? Second sub is big deal.... not the financial part but the wife factor mostly... She hates even the one I have ... also leaving this as it is ..and setting up a close field listening with a pair of active monitors at my work place might be the another option .. What do you think ?

 

[RayDunzl]

Show a measurement with the subwoofer by itself.

 

[ppataki]

Dear all,

Last week I have created another topic about the null area right on my listening position and how to fix that.
As I also believe in science and measurements I ordered Umik-1, taken some measurements before investing (or may be not investing at all ) for DSP or even another sub.

Here is my first measurements.
Keep in mind that this is my first measurement with Umik-1 (with any mic actually) and just followed tutorial from a nice guy on YouTube

As it is recommended, I have taken several measurements from different listening positions and also some measurements without subwoofer

I have a pair of Monitor Audio Rx6 and a BK XLX200Mk2 subwoofer (I believe the rest shouldn't have an effect for that measurements.... oh may be cables... joking )
My sub is rolled off around 80hz and has a 90 degree phase as of now... these are all subject to change ... and by the way, the mesh grills of the speakers and the sub was on ... I am hearing significant change when I put them away at high frequencies (but not the subject for now )

My ideal listening position with sub.

View attachment 217253

My listening position while I am standing

View attachment 217254

Another listening position .. very close to sub and left speaker ... (feels a bit boomy now) sitting at 90 degree to speaker and sub

View attachment 217255

My ideal listening position without sub

View attachment 217256

and ideal listening position as I am standing but without a sub

View attachment 217257


Observations ...
I must say that I am bit puzzled with these measurements ...
First, without a sub scenario... I am hearing significantly better low frequency while I am standing but the measurements seems not justifying this There is two graphs on top ...

View attachment 217258


Same goes to with sub measurements as well..

View attachment 217259

and with and without a sub scenario on my ideal listening position


View attachment 217260

What I am hearing is a lot when I listen music... but the measurements show not that much ... may be missing something ??


Question ...
Is the patient dead or can be survived with my a better sub with bit more features or bit better placement) as replacement .. or a DAP can help me a bit about anything ... or is it necessary (must may be ) to buy a second sub... ? Second sub is big deal.... not the financial part but the wife factor mostly... she hates even the one I have ... also leaving this as it is ..and setting up a close field listening with a pair of active monitors at my work place might be the another option .. What do you think ?

Can you please attach the zipped measurement file?
Thank you

 

[atoprak]

@RayDunzl Measurements are attached

 

[goat76]

Why do you want to optimize for when you stand up, are you often standing in that position when you listen to music?

I only optimize my house curve for the optima sweet spot because that's the only time I'm really concentrating on the music listening, otherwise, it's just for background listening and the "perfect sound" is not important.

When it comes to room treatments and EQ adjustments it's never about optimizing the sound for the whole room, it's just about how it sounds in the sweet spot, and maybe the other seats close to that position if compromises are needed to be done for more than one listening position. It doesn't matter if it's a bass boom in some corner in the room if that bass boom doesn't reach your ears in the listening position/s.

Is your subwoofer really rolled off at 80 Hz, or do you mean it has the crossover at that frequency?
Anyway, it doesn't seem to do much or anything for the bass, are you sure it receives any signal in those measurements?

 

[atoprak]

Why do you want to optimize for when you stand up, are you often standing in that position when you listen to music?

I only optimize my house curve for the optima sweet spot because that's the only time I'm really concentrating on the music listening, otherwise, it's just for background listening and the "perfect sound" is not important.

When it comes to room treatments and EQ adjustments it's never about optimizing the sound for the whole room, it's just about how it sounds in the sweet spot, and maybe the other seats close to that position if compromises are needed to be done for more than one listening position. It doesn't matter if it's a bass boom in some corner in the room if that bass boom doesn't reach your ears in the listening position/s.

Is your subwoofer really rolled off at 80 Hz, or do you mean it has the crossover at that frequency?
Anyway, it doesn't seem to do much or anything for the bass, are you sure it receives any signal in those measurements?

Something is wrong... there is no movement on sub while sine wave testing
but the sub is working with the music .. cant understand

 

[goat76]

Something is wrong... there is no movement on sub while sine wave testing
but the sub is working with the music .. cant understand

It's simple, you are not sending a signal from the subwoofer channel when you are measuring just left, right, or both the main channels.

I think you can configure the received signal from the subwoofer in the settings of REW. In preferences, you can tick the box for "Secondary Output" and maybe find the correct channel from your subwoofer?

Personally, I have never done it, I have my REL subwoofers connected from the same binding posts as my main speaker's and just turn on or off the subs when I measure the room response. If you don't figure it out by yourself, someone else can probably tell you how it's done.

 

[atoprak]

It's simple, you are not sending a signal from the subwoofer channel when you are measuring just left, right, or both the main channels.

I think you can configure the received signal from the subwoofer in the settings of REW. In preferences, you can tick the box for "Secondary Output" and maybe find the correct channel from your subwoofer?

Personally, I have never done it, I have my REL subwoofers connected from the same binding posts as my main speaker's and just turn on or off the subs when I measure the room response. If you don't figure it out by yourself, someone else can probably tell you how it's done.

Sorry ...
Made a huge mistake ...
My sub acts weird in a way that I couldnt understand so far ... may be kind of signal cancellation ... I am using my stereo amps PreOut amp outs (L+R) to connect my subs low level inputs .. they are working fine while listenin music .. bu on sin wave, these channels probably get cancelled on Subs pre amp, and sub was not acting ... When I unplug the one of the line in and put the second one to Mono in, It worked... shame on me. .. Sorry again...

I have modified the main thread with my new measurements ...

 

[atoprak]

Can you please attach the zipped measurement file?
Thank you

Sure, I have attached them

 

[atoprak]

Show a measurement with the subwoofer by itself.

Sure, you can find the sole sub measurement on the main topic

 

[holbob]

What gain is the sub at? Turn it up if it doesn't result in excessive distortion. I've owned 2 xls200 in the past, I don't remember the distortion being that high.

 

[dc655321]

Sure, you can find the sole sub measurement on the main topic

Your sub clearly is not crossed over at 90Hz. Start there…

 

[ppataki]

@atoprak
I have taken a look at your measurements (jnew2_nosub) and just playing around with it in REW and came up with the below EQ:

I used 1/12 octave smoothing, set the target to 64.5dB, set the range to 20-20kHz and did not allow REW to introduce any boosting filters
The result looks way better than your original frequency response

You could further add a low cut filter in the Target type (by setting it to Full Range speaker) but I think in general this alone will help tremendously

The EQ filter values are attached - you can use those in any software or hardware EQ (I prefer CraveEQ) or you can also save the filter impulse response in REW and use it in a Convolver

You could try this per channel too (Left and Right individually), that will provide even better results (in that case make sure to set the Target level to the same value so the volume of the channels will be the same)

The dips you can try to fill by allowing REW to use boosting filters by even lowering the Target to around 60dB and set the Individual Max Boost and Overall Max Boost to 18 and 12 respectively - but then some unwanted ringing might occur; you will need to try that to see/hear for yourself

Then also you can use a volume boost of 10-15dB to compensate for the volume loss due to lowering the Target above (just be careful not to run into digital clipping - you can avoid that by using volume control at the beginning of the audio chain, for example Jriver's internal 64-bit volume control)

EDIT: forgot to add that after all this you might need to add a 'room curve' to increase the low end and decrease the high end. You can do that either in REW using the Room Curve feature or using a second instance of an EQ and create a custom curve there (I personally prefer the latter). I use a boost (low shelf) at 100Hz with Q=1 and use a cut (high shelf) at 20kHz with Q=0.2

 

[holbob]

All a bit pointless until he integrates the subwoofer properly with gain/xover/delay settings.

 

[atoprak]

Well, actually I realised that I have set "LFE" to "out" position while I was trying to fix my issue with sub not working initially with REW, Sin wave.. ) ... till then I have realised a bit muddy sound around 100-300hz range.. way over boosted.. I checked the setting and saw that and turn the switchback to "in" position ... that muddiness gone and the sub started to act like properly (in very low frequency range) ..

The problem is that these measurements are taken with this settings ... bit boosted ... I think I have to take these measurements again ...

 

[atoprak]

@atoprak
I have taken a look at your measurements (jnew2_nosub) and just playing around with it in REW and came up with the below EQ:

View attachment 217518

I used 1/12 octave smoothing, set the target to 64.5dB, set the range to 20-20kHz and did not allow REW to introduce any boosting filters
The result looks way better than your original frequency response

You could further add a low cut filter in the Target type (by setting it to Full Range speaker) but I think in general this alone will help tremendously

The EQ filter values are attached - you can use those in any software or hardware EQ (I prefer CraveEQ) or you can also save the filter impulse response in REW and use it in a Convolver

You could try this per channel too (Left and Right individually), that will provide even better results (in that case make sure to set the Target level to the same value so the volume of the channels will be the same)

The dips you can try to fill by allowing REW to use boosting filters by even lowering the Target to around 60dB and set the Individual Max Boost and Overall Max Boost to 18 and 12 respectively - but then some unwanted ringing might occur; you will need to try that to see/hear for yourself

Then also you can use a volume boost of 10-15dB to compensate for the volume loss due to lowering the Target above (just be careful not to run into digital clipping - you can avoid that by using volume control at the beginning of the audio chain, for example Jriver's internal 64-bit volume control)

EDIT: forgot to add that after all this you might need to add a 'room curve' to increase the low end and decrease the high end. You can do that either in REW using the Room Curve feature or using a second instance of an EQ and create a custom curve there (I personally prefer the latter). I use a boost (low shelf) at 100Hz with Q=1 and use a cut (high shelf) at 20kHz with Q=0.2

Thanks for all the details and work .. very, very much appreciated.

I am not fan of using subwoofers even if these very much required for the full range sound (and also fun part... ) .. It is unbelievable thing for me that If I can fix this and eliminate sub ...
First of all, I am using my computer to stream music to my DAC.. thats being handled with my Bluesound Node streamer... So there is no way for me to EQ my my system with very basic tone controls on my stereo amp and streamer. .... which led me to think about a DSP, right ?

Can I really get your "predicted" curve with these settings and a help of DSC like MiniDSP or anything similar ?

 

[ppataki]

Thanks for all the details and work .. very, very much appreciated.

I am not fan of using subwoofers even if these very much required for the full range sound (and also fun part... ) .. It is unbelievable thing for me that If I can fix this and eliminate sub ...
First of all, I am using my computer to stream music to my DAC.. thats being handled with my Bluesound Node streamer... So there is no way for me to EQ my my system with very basic tone controls on my stereo amp and streamer. .... which led me to think about a DSP, right ?

Can I really get your "predicted" curve with these settings and a help of DSC like MiniDSP or anything similar ?

You are welcome
I am also not a fan of subs hence I started with your no sub measurement
Yes, REW's prediction is usually pretty accurate so what you see on that curve is really close to what you will see in reality too
Since you already use a computer as a source (thumbs up!) you don't really need a hardware DSP like miniDSP but a software one like Jriver
That will provide you with endless flexibility and better (actually the best) quality

 

[atoprak]

You are welcome
I am also not a fan of subs hence I started with your no sub measurement
Yes, REW's prediction is usually pretty accurate so what you see on that curve is really close to what you will see in reality too
Since you already use a computer as a source (thumbs up!) you don't really need a hardware DSP like miniDSP but a software one like Jriver
That will provide you with endless flexibility and better (actually the best) quality

Damm , typo… no I am not using my computer all streaming is being handled by my Bluesound Node player …

I really don’t know why I am doing all that mistakes about this topic … finally, a typo… not even a typo missing negation May be I am cursed by my wife not spending any pennies on electronics…

 

[ppataki]

Damm , typo… no I am not using my computer all streaming is being handled by my Bluesound Node player …

I really don’t know why I am doing all that mistakes about this topic … finally, a typo… not even a typo missing negation May be I am cursed by my wife not spending any pennies on electronics…

No worries
In this case you can either add a hardware DSP to your chain (like a miniDSP) or you can still add a computer at the beginning of the chain

 

[goat76]

Thanks for all the details and work .. very, very much appreciated.

I am not fan of using subwoofers even if these very much required for the full range sound (and also fun part... ) .. It is unbelievable thing for me that If I can fix this and eliminate sub ...
First of all, I am using my computer to stream music to my DAC.. thats being handled with my Bluesound Node streamer... So there is no way for me to EQ my my system with very basic tone controls on my stereo amp and streamer. .... which led me to think about a DSP, right ?

Can I really get your "predicted" curve with these settings and a help of DSC like MiniDSP or anything similar ?

If you don't like subwoofers, you have probably never got them to integrate well with the main speakers. Well-integrated subwoofers will never be heard as separate sound sources if set up correctly, just add clean deep bass. And like you say, if you want to have the "full-range sound" the subwoofers are probably needed in most systems.

As holbob said, I think you should get the subwoofer integration well before it's time for any EQ adjustments to the system. And when it comes to EQ, you should probably not do too many adjustments over at least 300-500 Hz, based on the "house curve" measurements. As I have understood it, the direct sound is the dominating factor you hear from the 300-500 Hz and upward in frequency from your speakers, therefore, you should (maybe by measuring the speaker at a closer range or with the use of gated measurements) make sure it's really is the direct sound that needs adjustments over that point.

I'm not an expert on REW, maybe someone with better knowledge can tell us how to set up REW for gated measurements at a preset frequency point?

Personally, I don't do any EQ adjustments over 100 Hz.