What could cause this issue?

[rafaeldatarock]

Hi everyone!

After messing around with a tone generator and an EQ I sorta managed to correct a major error in my listening setup. But only sorta...
I noticed two especially problematic frequencies:

• 113Hz (way too quiet) ±18dB
• 123Hz (way too loud) ±18dB

In both cases, the correction seems to work best with a very sharp Q (factor 10).
I think the 123Hz bump is simply a standing wave, when I pull it down by 18dB's the volume levels out nicely compared to lower and higher frequencies.
The 113Hz dip is a but more interesting, because this dip only occurs: in front, between the speakers. Not: in front, outside the speakers. It's as if this exact frequency is exactly 180° out of phase between both speakers.

So this made me wonder, what could be the cause of the 113Hz problem? I don't know if this makes sense, but it is as if the 123Hz bump problem is caused by the length of my room, and the 113Hz dip problem is caused by the width of my room. I am on the right track here?

I'm interested to hear what you think!

P.S. Attached is a screenshot of the correction curve which smooths out both, for my listening position.

 

[rafaeldatarock]

Anyone?

 

[thothsong]

Have you tried plugging your room dimensions and speaker placement into REW's Room Simulation?

 

[ddude003]

Try this https://amcoustics.com/tools/amroc
Post up your .mdat file... Screen shots aren't much use... Also, a little info about your kit and room dimensions would be helpful for those of us who might help...

Depending on how narrow the dip (null) is it may be inaudible... Also, you may not want to boost it by +18db with traditional EQ...
For extra credit... What is the size/distance of a 113Hz wave? And does it equal the width of your room?

 

[Todd Anderson]

What kind of system do you have? Speakers or speakers and subs?

 

[JStewart]

Hi everyone!

After messing around with a tone generator and an EQ I sorta managed to correct a major error in my listening setup. But only sorta...
I noticed two especially problematic frequencies:

• 113Hz (way too quiet) ±18dB
• 123Hz (way too loud) ±18dB

In both cases, the correction seems to work best with a very sharp Q (factor 10).
I think the 123Hz bump is simply a standing wave, when I pull it down by 18dB's the volume levels out nicely compared to lower and higher frequencies.
The 113Hz dip is a but more interesting, because this dip only occurs: in front, between the speakers. Not: in front, outside the speakers. It's as if this exact frequency is exactly 180° out of phase between both speakers.

So this made me wonder, what could be the cause of the 113Hz problem? I don't know if this makes sense, but it is as if the 123Hz bump problem is caused by the length of my room, and the 113Hz dip problem is caused by the width of my room. I am on the right track here?

I'm interested to hear what you think!

P.S. Attached is a screenshot of the correction curve which smooths out both, for my listening position.

Although most of it goes right over my head, this thread may provide a clue as to what is going on for you.
The OP is the author of FlexAsio, by the way.

Bass arriving out of phase at the listening position

So riddle me this: The above graph shows the response at my listening position from my left speaker (red), right speaker (green) as well as the response of both playing at the same time (blue). All graphs use 1/12 octave smoothing for readability. Ignore the large null on the right channel...

www.audiosciencereview.com

 

[NBPK402]

I do not know if this will help, but I read somewhere that when tuning your speakers you should have the left and right channel both on when tuning bass. They said that by having both channels on bass eliminates bass being cancelled. They said that your mids and highs could still be tuned individually.

 

[rafaeldatarock]

Thanks for the responses everyone!

 

[rafaeldatarock]

What kind of system do you have? Speakers or speakers and subs?

I have a set of Adam A7's paired with a sub (BNS SDS-Sub mkII) by an obscure and long gone speaker builder from the Netherlands.
I don't have a lowcut on the Adam's, but I do have a highcut on the sub at +- 80Hz. (I have no idea what slope, can't find any documentation on this sub online and the booklet that came with it is of a different model)

 

[rafaeldatarock]

Have you tried plugging your room dimensions and speaker placement into REW's Room Simulation?

I will do this and report back!

 

[rafaeldatarock]

Try this https://amcoustics.com/tools/amroc
Post up your .mdat file... Screen shots aren't much use... Also, a little info about your kit and room dimensions would be helpful for those of us who might help...

Depending on how narrow the dip (null) is it may be inaudible... Also, you may not want to boost it by +18db with traditional EQ...
For extra credit... What is the size/distance of a 113Hz wave? And does it equal the width of your room?

Will definitely not use +18dB EQ!
And you are spot on, the length of a single 113Hz cycle is ~3,04m.. Which is exactly the width of my room. Thanks!

 

[rafaeldatarock]

Have you tried plugging your room dimensions and speaker placement into REW's Room Simulation?

Mmh, this doesn't seem to match up with the problems i'm experiencing..

 

[ddude003]

Will definitely not use +18dB EQ!
And you are spot on, the length of a single 113Hz cycle is ~3,04m.. Which is exactly the width of my room. Thanks!

Nulls caused by room mode(s) can not be corrected by boosting EQ... Because direct sound is cancelled by the reflected sound... If you try to equalize, boost, you will increase both direct and reflected sound... A catch 22... And traditional EQ at those low frequencies may cause (pre)ringing...

Speaker placement, sub placement, multi subs, and bass trapping are pretty well known solutions... And then there are some interesting ways like...

 

[Todd Anderson]

I have a set of Adam A7's paired with a sub (BNS SDS-Sub mkII) by an obscure and long gone speaker builder from the Netherlands.
I don't have a lowcut on the Adam's, but I do have a highcut on the sub at +- 80Hz. (I have no idea what slope, can't find any documentation on this sub online and the booklet that came with it is of a different model)

Hmm. So this is happening well above a crossover point between your sub and Adams. I'm baffled. It does look like a phase issue... I wonder if wiring in one of the speakers is crossed?

Admittedly, this is a bit outside of my realm of expertise. Super interesting, tho

 

[ddude003]

@rafaeldatarock... If I read the specs on those Adams correctly, they go down into the 40Hzs... You might try moving your subs crossover down somewhere a little above where the Adams go down to... Post up an .mdat file with single Left, single Right, and single Sub sweeps... And what are the rooms measurements?

Is this a Near field or desktop type system? Could be reflections from ceiling and desktop or mixing console... It is always helpful to give up a little more information about your use case and the entire kit involved...