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Sub bass of the subwoofer in a small room

Phoney

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I have the Q Acoustics 2070Si sub in a small room (13m² untreated square room, about 5m*2.6m*2.6m) with Airpulse A100 speakers near field. The sub is set to crossover 60hz. When I play electronic music with sub bass in it, the sound certainly sounds off and unpleasant. I'm having no issues with the rest of the sound, but sub bass surely doesn't go too well with my room. I'm not looking to buy treatment, so what seems like the best and easiest fix for this? I use eq, so I could put on a dip or low pass filter at 40hz and below for example. I could also just turn down the volume of the sub itself, but in doing so I will also have less volume at around 60hz +/-.
Info about the sub

20221019_115009.jpg

20221019_115018.jpg

20221019_115047.jpg
 

flipflop

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1) Acquire a measurement mic (UMIK-1 or equivalent)
2) Install REW and run a MMM measurement:
3) Create EQ filters that address room modes below the transition frequency
4) Run another measurement to confirm the filters are working as intended
 

DJNX

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Way too many things of notice.

-Why 60Hz with such small monitors?
-Is it a proper crossover with lowpass filter and highpass filter?
-Are you sure about the problematic frequencies? Have your run test tones or sweeps? In such small room it would be unsurprising the modes that are giving you problems are in the 100-250 Hz range.
-What is your bed made of? You can take advantage of that and get a mattress with dense, layered foam and it should act as absorption.
-Try doing tests with your door open and closed.
-You said you can just turn the volume down on the sub. Is your sub calibrated? A sub is for frequency range extension. Once calibrated the volume of the sub is not touched again.

If it’s not calibrated, then you could just be overpowering the signal (and your room) with bass.
 
OP
Phoney

Phoney

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Way too many things of notice.

-Why 60Hz with such small monitors?
-Is it a proper crossover with lowpass filter and highpass filter?
-Are you sure about the problematic frequencies? Have your run test tones or sweeps? In such small room it would be unsurprising the modes that are giving you problems are in the 100-250 Hz range.
-What is your bed made of? You can take advantage of that and get a mattress with dense, layered foam and it should act as absorption.
-Try doing tests with your door open and closed.
-You said you can just turn the volume down on the sub. Is your sub calibrated? A sub is for frequency range extension. Once calibrated the volume of the sub is not touched again.

If it’s not calibrated, then you could just be overpowering the signal (and your room) with bass.

60hz is the high pass filter of the sub, I didn't adjust low pass. Airpulse A100 has a normal low pass in it's original frequency response that starts at around 72-74hz. It makes sense to put the low pass on 60hz, since both will produce bass between 60 and 74hz? The filters are not brick walls. Using a tone generator, I felt like 60hz high pass on the sub sounded okay and the bass sounds kind of balanced when you consider bad placement in the room and no treatment.

Airpulse A100 Measurements Predicted in-room Frequence Response Powered Speaker Monitor (1).png


I'm listening pretty near field, while I did have problems from 100-250hz, placing the speakers closer to me and further away from the wall behind kind of solved that problem and it doesnt sound that much off for the most part. I only have issues when music has content below 30-40hz, it feels like the low bass affects the rest of the spectrum.

Buying a measurement mic will add to the cost, I don't need perfect balance. I use a tone generator for approximity and response seems okay enough for my use. It's just that when my double 6,25 inch woofer plays the lowest frequencies in my small room, it seems like it's causing issues. Other types of music seems pretty good to me.
 

DJNX

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Great, you are not as lost as I somewhat feared.
OK then, first, you didn't answer if the sub was calibrated. (Without calibration you could be outputting 3 or 6dB more than in the source, and that can be enough to mess up things pretty badly)
Second, could you provide some example tracks? Let's take a look on a spectrogram and see how low they actually go.
 

FrantzM

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Hi

You are an enthusiast, no doubt. Save and buy a measurement microphones. Automatic recommendation is the miniDSP Umik-1, around $125.oo shipped in the USA. One of the best investment you would have made, also long term: You'll use it for years and across systems.

Peace
 

Chrispy

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I wouldn't expect much from that sub below 30hz....and probably not too much below 40 either (or pretty much any sub with such small drivers). Don't see much info with your link as to lower frequency spec (like an f3 or f6, even though that may not be mean much depending on spl level it's quoted at)....ever see a third party test of this sub with measurements? Are you using the low pass filter adjustment on the sub at 60?
 
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Phoney

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Great, you are not as lost as I somewhat feared.
OK then, first, you didn't answer if the sub was calibrated. (Without calibration you could be outputting 3 or 6dB more than in the source, and that can be enough to mess up things pretty badly)
Second, could you provide some example tracks? Let's take a look on a spectrogram and see how low they actually go.

Hmm calibration? I put the phase at 0. It has a DSP on the back. I'm a bit lost on some things, like calibration.

20221011_184003.jpg


Here is the track where I really noticed it at first

I wouldn't expect much from that sub below 30hz....and probably not too much below 40 either (or pretty much any sub with such small drivers). Don't see much info with your link as to lower frequency spec (like an f3 or f6, even though that may not be mean much depending on spl level it's quoted at)....ever see a third party test of this sub with measurements? Are you using the low pass filter adjustment on the sub at 60?

I checked with my tone generator, it shakes the room quite a bit down to 30hz. It seems like it drops off below 30hz like you say. So the problem area is possibly 30-40hz. Some tracks seems to benefit from the sub, like they sound pretty good with the sub and bass light without. But with deeper bass it seems a bit too much. It could also be that if a track uses too much of the sub frequencies in general, it becomes a problem. Might not just be 30-40hz. The sub is 9 years old, so not really the newest technology. However upgrading it would be costly, since I don't really get much from selling.
 

Chrispy

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Hmm calibration? I put the phase at 0. It has a DSP on the back. I'm a bit lost on some things, like calibration.

Here is the track where I really noticed it at first



I checked with my tone generator, it shakes the room quite a bit down to 30hz. It seems like it drops off below 30hz like you say. So the problem area is possibly 30-40hz. Some tracks seems to benefit from the sub, like they sound pretty good with the sub and bass light without. But with deeper bass it seems a bit too much. The sub is 9 years old, so not really the newest technology. However upgrading it would be costly, since I don't really get much from selling.
I'm spoiled but also have much larger rooms, but would love to see a test of that :) Sounds hopeful but I still wouldn't expect a very high spl that low (any measurement of that?). Phase at 0 is a good start, but flip it to 180 (assuming that's the control it's got, which is actually just flipping polarity) and see which gives you the stronger response. The low pass filter setting on the sub is 60? What dsp particularly does it have?
 
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Phoney

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I'm spoiled but also have much larger rooms, but would love to see a test of that :) Sounds hopeful but I still wouldn't expect a very high spl that low (any measurement of that?). Phase at 0 is a good start, but flip it to 180 (assuming that's the control it's got, which is actually just flipping polarity) and see which gives you the stronger response. The low pass filter setting on the sub is 60? What dsp particularly does it have?

It has a phase knob aswell as you see for more exact adjustments. Yeah I guess the low pass filter is at 60hz on the sub, I said high pass earlier by mistake. It doesn't have a high pass filter for the speakers, but their frequency response has one already (see pic above) which rolls off naturally at around 72-74hz. Unfortunately I can't find measurements or measure the sub, but it's low pass filter goes down to 50hz minimum and it sounds pretty loud to me down to 30hz in a tone generator. Maybe it starts rolling off at 32hz, but I think it plays well below 40hz before it starts rolling off.
 

Chrispy

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It has a phase knob aswell as you see for more exact adjustments. Yeah I guess the low pass filter is at 60hz on the sub, I said high pass earlier by mistake. It doesn't have a high pass filter for the speakers, but their frequency response has one already (see pic above) which rolls off naturally at around 72-74hz. Unfortunately I can't find measurements or measure the sub, but it's low pass filter goes down to 50hz and it sounds pretty loud to me down to 30hz in a tone generator. Maybe it starts rolling off at 32hz, but I think it plays well below 40hz before it starts rolling off.
Then vary the knob and see if you get particularly strong response at other than 0..... I thought you meant low pass but wasn't sure.....I'd set your low pass higher than 60 with those speakers....but experiment there as well. Does it have some sort of eq when you say it has dsp ?
 
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Phoney

Phoney

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Then vary the knob and see if you get particularly strong response at other than 0..... I thought you meant low pass but wasn't sure.....I'd set your low pass higher than 60 with those speakers....but experiment there as well. Does it have some sort of eq when you say it has dsp ?

Oh okay, what LPF frequency on the knob do you think would be appropriate with the response of the speakers I posted earlier? No, it doesn't have eq, but I can eq it in roon. The eq will affect both the speaker and the sub simultaneously.
 

Tom C

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Sounds to me like you’ve nearly zeroed in on it.
Even if you had a measurement mike today, it would do you no good to only know where the problem is. You have to be able to correct it. Do you have EQ available to you? If so, you can try applying a cut to the frequency range you suspect contains the problem. If you get an improvement, you’re on the right track.
If you can’t EQ, that’s a problem you’ll have to solve before you can progress.
 

Chrispy

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Oh okay, what LPF frequency on the knob do you think would be appropriate with the response of the speakers I posted earlier? No, it doesn't have eq, but I can eq it in roon. The eq will affect both the speaker and the sub simultaneously.
Was more curious what the sub had onboard. I'd probably start at 75-80.

ps just saw the photo of the back of the sub....I guess it hadn't loaded when I scrolled thru originally.
 
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Tom C

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I don’t have any sub in my house crossed lower than 100Hz, and that’s with a unit that has a 10” woofer in the upper cabinet. That sub has an 18” driver. For bookshelf style speakers, I would start at 125 or even 150. But that’s just me. There are plenty of people who don’t care for that much bass.
 

Chrispy

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I don’t have any sub in my house crossed lower than 100Hz, and that’s with a unit that has a 10” woofer in the upper cabinet. That sub has an 18” driver. For bookshelf style speakers, I would start at 125 or even 150. But that’s just me. There are plenty of people who don’t care for that much bass.
Is that using an actual crossover, tho? Or you just like some overlap? All he's got is the sub's lpf....
 

Tom C

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I’m not a Roon user, so I don’t know its capabilities, but the OP says he has EQ available in Roon.
As to your question, it’s a mix. Two of my systems have built-in high pass and low pass, another is multichannel home theater I use with JRiver and Denon AVR, with actual crossovers. For the music only systems, I like to let the sub run full range, and use a high pass on the mains, set to cut the low frequencies where the distortion is the greatest. With formal room correction, the bass response is even and well controlled. The music only systems have a lumpy bass response, and some uncontrolled room modes, but give a suffusive quality I find quite enjoyable.
 

sarumbear

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I have the Q Acoustics 2070Si sub in a small room (13m² untreated square room, about 5m*2.6m*2.6m) with Airpulse A100 speakers near field. The sub is set to crossover 60hz. When I play electronic music with sub bass in it, the sound certainly sounds off and unpleasant. I'm having no issues with the rest of the sound, but sub bass surely doesn't go too well with my room. I'm not looking to buy treatment, so what seems like the best and easiest fix for this? I use eq, so I could put on a dip or low pass filter at 40hz and below for example. I could also just turn down the volume of the sub itself, but in doing so I will also have less volume at around 60hz +/-.
Info about the sub

View attachment 238042
View attachment 238043
View attachment 238044
It’s not your room. Your desktops need filtering low frequencies.

The sub has a low pass filter in built but there’s no matching high pass in your system. As the word implies you need to “crossover” the filters in both high and low speakers.

The only solution is to replace your amplifier which has high pass filter built in. Then set it to cut at 100Hz and reset your subwoofer to 100Hz as well. Your room is too small you will be perfectly OK with a crossover frequency of 100Hz.
 
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Phoney

Phoney

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I’m not a Roon user, so I don’t know its capabilities, but the OP says he has EQ available in Roon.
As to your question, it’s a mix. Two of my systems have built-in high pass and low pass, another is multichannel home theater I use with JRiver and Denon AVR, with actual crossovers. For the music only systems, I like to let the sub run full range, and use a high pass on the mains, set to cut the low frequencies where the distortion is the greatest. With formal room correction, the bass response is even and well controlled. The music only systems have a lumpy bass response, and some uncontrolled room modes, but give a suffusive quality I find quite enjoyable.

I have EQ in Roon, but I can't put lpf and hpf seperately for the speaker and the sub there. So that's why I just use the lpf knob on the back of the sub, while the speakers themselves already has a built in hpf in its FR which rolls off at around 74hz.
 

sarumbear

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I have EQ in Roon, but I can't put lpf and hpf seperately for the speaker and the sub there. So that's why I just use the lpf knob on the back of the sub, while the speakers themselves already has a built in hpf in its FR which rolls off at around 74hz.
EQ and filter are different processes. You can’t replace a cut filter with an EQ.
 
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