It depends on the specific frequencies. Sub 100hz omni-directional low bass response "seat to seat", consistency can be improved to a decent level +/- 3db with multiple subs & dsp but you would have to be willing to place 3 or more subs anywhere in the room and spend a lot of time tweaking the set up. For an overall even tonality and good stereo image, Besides the physical position of the speakers and acoustic treatment, You also have to consider the off-axis performance of the speaker itself. Even if there was no comb filtering, It would not be ideal to move away from the sweet spot as you'd lose the stereo image. So in a music studio environment a "good bass everywhere in room" is not all that important as the engineer should never move away from the sweet spot and use a good pair of ref headphones if one's experiencing any comb filtering cancellations.
as an acoustician you want to control the frequency response and other temporal phenomena in a certain are of the room (the mixing engineer seat or the main listener seat) and not everywhere
Four subs near each corner, eq the peaks out, accept the nulls that are left. You'll lose the co-located SPL, you'll gain the smoother seat to seat response.
@@sh91899 What trap will deal with a null in the 15-30hz range? The wavelength is too dang long, isn't it? That'd be another advantage of quad subs. (It's certainly an expensive answer, but not compared to some of the craziness in the audiophile world...)
Ryan Kramer those are odd nulls... diaphragmatic would work as well as tuned limp mass and helmholtz resonators. I plan to integrate AVAA. Not cheap but pretty small and rated for 15-150 (I think).
This is why you should use single subwoofer that takes care of everything below ~75-100hz and it helps the issue quite a bit. In Live sound we do stuff like this all the time. I don't like using two spaced subwoofers as many people do in small setups, I like single in the middle or two as a cardioid (if I want to limit the volume at the stage or i'm worried of reflections from surrounding walls) to get more even bass response throughout the audience. In larger setups doing complex arrays and making compromises between bass response being even and bass being loud are every day occurence.
This is why some of us use multiple subwoffers. The best I have heard is at my friend that have 16 12"woffers placed like a frame around the front of the room. 2speakers=bas problems.
I have one question: The bass hunter technique says, place your speaker in the corner, after finding the right spot re-place them. Doesn't that mean that you "move" the peak and nulls of the standing wave again after replacing the speakers, thus leading to a new situation (shifted peaks and nulls of the room modes)?
No, the standing waves are created by the dimentions of the room. Moving the speaker out of the corner obviously will change the sound, but based on the room modes, you have found your ideal listening position and can now focus on nailing the optimal speaker position.
Hey Jesco, I've got a bit of an issue in my room at around 260Hz - I've noticed middle C sticks out a lot compared to other notes. What would you recommend to help with that? It's not super low, but it's almost a mid frequency. Could also be getting the lower octave at 130hz-ish. Thinking of getting 2 or 3 bass traps to put around the room. I don't necessarily have a lot of room in the corners due to doors and cupboards, so I'm thinking a wall/ceiling solution might be best. Cheers
A minimum of 3 bass on each corner is what Ethan Winer recommends. The more coverage of that corner the better. Go at least 16 inches from the corner and it’s best to hang your bass traps. Leave an air gap for better low end absorption. Low frequency’s build up in the corner of your walls the most and I’ve read that covering the tri-corners closest to the floor or the ceiling is better than placing it in the dead center but I could be mistaken. Use a hybrid acoustic panel behind you aka your rear wall. Hybrid acoustic panels usually have pine wood as a casing. This will help absorb the low frequencies and also scatter the mid and high frequencies. Again, leave an air gap for more low end absorption. If you have a low 8 foot ceilings use a cloud acoustic panel. This is a panel that usually hangs directly above your studio desk. The smaller the room the more problems you’ll have with frequencies reflecting from the walls clashing together causing phase cancellation of certain frequencies. You can also add a skyline diffuser or a hybrid acoustic panel behind you on the rear wall to scatter the high and mid frequencies. I usually stop there and never worry too much about the wall in front of me as long as the side walls, corners and back walls are taken care of that should usually be enough to reduce reflections. If you want maximum absorption and want to deaden your room as much as possible don’t use a diffuser or hybrid acoustic panel. Just use bass traps. Buy your acoustic panels on Etsy and no matter how aesthetically pleasing some might look from countries like Ukraine, etc.. be wary of the insulation they use in their panels. Rigid fiberglass or Mineral wool/Rockwool is ideal. Broadband acoustic panels should be the most common and most reliable for a home studio.
But even if I find the sweet spot for low end in my room by walking around listening to two speakers play stereo music, isn't that low end response going to change as soon as I move my speakers and desk to my newfound listening position? Where does this end? What if when I move everything to accommodate that spot it sounds wonky again in the lows? Great videos by the way. I love what you're doing.
You have to understand that Axial modes are along two parallel walls, So you have to treat both parallel walls. You also might have some modes against the side walls, and other modes along the front/rear walls and maybe another mode between the floor and ceiling. And with small rooms, you may find that you simply don't have the room to fill the room with low frequency treatment. The best Low Frequency absorption devices are at least 12inch or thicker in terms of the depth and you may need them all along the walls and ceiling thus reducing the useable size of the room. I would highly suggest checking out Acoustic Fields, they have better videos explaining low frequency problems and how to treat and what to look for…. Plus, they have the best designed products using activated carbon which they have patents on, but they do sell DIY plans and you can buy the carbon from them and make your own and save money.
There is only one listening position in stereo, right? Why expect bass to be perfectly balanced anywhere else? Surely the changes in level are due to room mode peaks and troughs??
@@mladia Hi,,, a little yes, lol. One thing even though not knowing the size of the room, treated well or not, 3 subs is likely overkill. Adding to a compound problem. Add treatment, for one sub is a lot, but the room has 3. 2 Subs placed correctly in a treated room can work if done right in the right space. I gave a vague answer not knowing the intended mix purpose or situations.
Just go to monophonic and be happy. Or, learn to live with the realities of stereo and be happy you aren't attempting to deal with 5.1, or 7.1, or....... lol! For all the purists, you could test using two double-bass violins about 8 - 10 feet apart. Walk around and experience all kinds of fun low-frequency interactions.
No. I found the best way to get rid of most annoying sound in general is just use good NC headphones where you can play your own silent relaxing music (or whatever you please). All low end problems dissapear also. And by far the cheapest solution, but still a compromise...
@@marcpanther7924 4 Months later and still suffering ? You mean from the neighbours music right ? Only other thing is talk to your neigbours or the police, or move, or try to not get angry about it. If you can feel it surely a basstrap isn't going to do anything for you, i'm sorry. Something is bothering me also and I can't do anything about it, living in an appartment where the neighbours smoke on the balcony and when we want some fresh air to come in....
Dear Jesco, Kudos for all the good work that you are doing. However, pl use some simple graphics where possible, they can be nicely hand-drawn too, but are needed for easier understanding. And last but the least - that halo light behind your head is really annoying and making me bipolar!
Great video - as always. Thank you. I have a question: Are standing waves independent of placement of the monitors and a sub, as they are a given by the room dimensions / frequency only? Or does the placement of the woofer create comb filters, and they influence the (fundamental) standing waves? Or are comb filters completely independent of the room standing waves? It's a question I'm struggling with for some time now Thanks a lot!
Not an expert (at all!) but my understanding of the comb filter effect he is talking about, is that it is an inherent issue BECAUSE you are using two seperate speakers to reproduce what is a "phantom" centre for the bass. Which is where we usually want the bass end to be. So i think you will find this effect even if you have two speakers set up in an open field, i.e. no room resonances or reflections at all. This is simple inherent in the physics when you use two speakers, which is why he said it wouldnt occur if you mixed in mono, with only one speaker. Of course as soon as you set up your monitors in a room, then all the room modes with standing waves (resonances) due to the dimensions of the room, and the path reflections such as the floor, ceiling walls, these all conspire to make your problem worse. These you can mitigate to a certain extent, with good sound treatment, symmetrical but not parallel wall construction (which is fine if you are building a studio room literally from the ground up, but who has that kind of budget for a home studio?!?) and other bass taming constructions. Bottom line, this is an irreducible issue, with two full range speakers. If you monitor with one sub, only for the entire bass end, and the rest of the frequency range by the stereo speakers, i would guess this might be the only way round this. Anybody can correct me here? Just a guess on my part!
The modes ("standing waves") of the room are independent of any sourcing. Mathematically, they are solutions to an equation without a source term. They indicate that if you put energy into the room, and remove it, there will be a resulting pressure which will be some combination of the infinitly many modes; that combination will depend on how you put energy into the room and where. When you add a loudspeaker to the room, the placement (and type, meaning monopole vs dipole) will decide how much each mode will be excited. And where you put your ears relative to the excited modes will of course also be of importance. But with one or more loudspeakers actually sourcing the room, you will have an additional issue, and that is what is called SBIR (Speaker Boundary Interface Response) as the sound can take a direct path to your ears, but also be reflected off of the walls. Audioholics have a good video on this topic th-cam.com/video/eXfpAn3gkGs/w-d-xo.html.
It's not about the number of ways as much as the crossover points and the distance between the acoustic centers of the drivers. If you're really close to the speakers like in nearfield the best monitors are often 3 way but they are designed with really tight driver spacing and crossovers unlike a 12" 2-way PA speaker for example which is quite the opposite with high xovers and large drivers. In that case the 3-way ATC will be much better than the 2-way QSC in the nearfield in terms of coherency.
You can achieve even bass across a couple feet with multiple subs. Not even close to even bass throughout the room. I've got duals, along with a NASTY dip at MLP around 55-70hz, then a minor null around 120. Even though I have duals (and really, really good subs from SVS), It took weeks of testing with REW, room correction, and about 30 different configurations, just to bring the null up a tiny bit. Meaning, its not a complete suck-out anymore. I can actually hear bass at 55hz...a little bit. But its not even close to even. Treating my room properly will help this out, but panels that help down to 50hz are 8-11" thick and very expensive. I don't want to say it will be fixed, because it is what it is. It can't be fixed, just managed. If you have a cancelation because of comb filtering or whatever the case, adding a sub isn't just going to power through that cancelation. Each sub will help bring it back to life, just a little bit. This is why people who have home theaters with multiple seating positions use 4 subs. For 1(or 2 very close) seating position(s), you can manage it with acoustics and dual subs, most likely. Some rooms just suck. I know people who have built their home theaters and studios from the foundation to the studs to the treatments and even with 4 subs..the bass is not going to be the same in any 2 spots that are at least 3-4 feet away from each other.
It depends on the specific frequencies. Sub 100hz omni-directional low bass response "seat to seat", consistency can be improved to a decent level +/- 3db with multiple subs & dsp but you would have to be willing to place 3 or more subs anywhere in the room and spend a lot of time tweaking the set up. For an overall even tonality and good stereo image, Besides the physical position of the speakers and acoustic treatment, You also have to consider the off-axis performance of the speaker itself. Even if there was no comb filtering, It would not be ideal to move away from the sweet spot as you'd lose the stereo image. So in a music studio environment a "good bass everywhere in room" is not all that important as the engineer should never move away from the sweet spot and use a good pair of ref headphones if one's experiencing any comb filtering cancellations.
A weight has been lifted off my shoulders, thank you so much for this video!
exactly!
Información de calidad como siempre, gracias por enseñarnos
as an acoustician you want to control the frequency response and other temporal phenomena in a certain are of the room (the mixing engineer seat or the main listener seat) and not everywhere
Jesko, du bist der fokkin beste. Great explanation about something i was tinking of too, while studying acoustics and treating my studio right now
Bro...I Just wanted to see if the bass changes?? The look on his face was priceless for sure....
Four subs near each corner, eq the peaks out, accept the nulls that are left. You'll lose the co-located SPL, you'll gain the smoother seat to seat response.
And correctly-placed traps will nail those nulls.
@@sh91899 What trap will deal with a null in the 15-30hz range? The wavelength is too dang long, isn't it? That'd be another advantage of quad subs. (It's certainly an expensive answer, but not compared to some of the craziness in the audiophile world...)
Ryan Kramer those are odd nulls... diaphragmatic would work as well as tuned limp mass and helmholtz resonators. I plan to integrate AVAA. Not cheap but pretty small and rated for 15-150 (I think).
Lol ok
This is why you should use single subwoofer that takes care of everything below ~75-100hz and it helps the issue quite a bit. In Live sound we do stuff like this all the time.
I don't like using two spaced subwoofers as many people do in small setups, I like single in the middle or two as a cardioid (if I want to limit the volume at the stage or i'm worried of reflections from surrounding walls) to get more even bass response throughout the audience.
In larger setups doing complex arrays and making compromises between bass response being even and bass being loud are every day occurence.
How does a subwoofer help if I have a 50hz peak for example? Thx
More excellent info. Thank you, sir!
Your videos are really good, straight to the points. (y)
thank you, your videos are really usefull and well explained
This is why some of us use multiple subwoffers. The best I have heard is at my friend that have 16 12"woffers placed like a frame around the front of the room. 2speakers=bas problems.
Excellent video advice ATB Peter
Great video!
I have one question:
The bass hunter technique says, place your speaker in the corner, after finding the right spot re-place them. Doesn't that mean that you "move" the peak and nulls of the standing wave again after replacing the speakers, thus leading to a new situation (shifted peaks and nulls of the room modes)?
No, the standing waves are created by the dimentions of the room.
Moving the speaker out of the corner obviously will change the sound, but based on the room modes, you have found your ideal listening position and can now focus on nailing the optimal speaker position.
Does a mono bass sub woofer help this problem, l guess the monitors will still give out enough bass the cause the effect you describe?
Another great video
Very useful information, thank you very much! :)
Pure Value !
Hey Jesco, I've got a bit of an issue in my room at around 260Hz - I've noticed middle C sticks out a lot compared to other notes. What would you recommend to help with that? It's not super low, but it's almost a mid frequency. Could also be getting the lower octave at 130hz-ish. Thinking of getting 2 or 3 bass traps to put around the room. I don't necessarily have a lot of room in the corners due to doors and cupboards, so I'm thinking a wall/ceiling solution might be best.
Cheers
i hope you had resolved the problem, but 1 diaphram bass trap on the note would help man
A minimum of 3 bass on each corner is what Ethan Winer recommends. The more coverage of that corner the better. Go at least 16 inches from the corner and it’s best to hang your bass traps. Leave an air gap for better low end absorption. Low frequency’s build up in the corner of your walls the most and I’ve read that covering the tri-corners closest to the floor or the ceiling is better than placing it in the dead center but I could be mistaken.
Use a hybrid acoustic panel behind you aka your rear wall. Hybrid acoustic panels usually have pine wood as a casing. This will help absorb the low frequencies and also scatter the mid and high frequencies. Again, leave an air gap for more low end absorption.
If you have a low 8 foot ceilings use a cloud acoustic panel. This is a panel that usually hangs directly above your studio desk. The smaller the room the more problems you’ll have with frequencies reflecting from the walls clashing together causing phase cancellation of certain frequencies.
You can also add a skyline diffuser or a hybrid acoustic panel behind you on the rear wall to scatter the high and mid frequencies. I usually stop there and never worry too much about the wall in front of me as long as the side walls, corners and back walls are taken care of that should usually be enough to reduce reflections.
If you want maximum absorption and want to deaden your room as much as possible don’t use a diffuser or hybrid acoustic panel. Just use bass traps.
Buy your acoustic panels on Etsy and no matter how aesthetically pleasing some might look from countries like Ukraine, etc.. be wary of the insulation they use in their panels. Rigid fiberglass or Mineral wool/Rockwool is ideal.
Broadband acoustic panels should be the most common and most reliable for a home studio.
But even if I find the sweet spot for low end in my room by walking around listening to two speakers play stereo music, isn't that low end response going to change as soon as I move my speakers and desk to my newfound listening position? Where does this end? What if when I move everything to accommodate that spot it sounds wonky again in the lows?
Great videos by the way. I love what you're doing.
yeah im thinking the same every timei move my setup... ill measure it anyway
You have to understand that Axial modes are along two parallel walls, So you have to treat both parallel walls. You also might have some modes against the side walls, and other modes along the front/rear walls and maybe another mode between the floor and ceiling. And with small rooms, you may find that you simply don't have the room to fill the room with low frequency treatment. The best Low Frequency absorption devices are at least 12inch or thicker in terms of the depth and you may need them all along the walls and ceiling thus reducing the useable size of the room.
I would highly suggest checking out Acoustic Fields, they have better videos explaining low frequency problems and how to treat and what to look for…. Plus, they have the best designed products using activated carbon which they have patents on, but they do sell DIY plans and you can buy the carbon from them and make your own and save money.
Where do I find the pdf
There is only one listening position in stereo, right?
Why expect bass to be perfectly balanced anywhere else?
Surely the changes in level are due to room mode peaks and troughs??
Agree 100% !
I use 3 subs.. 2 upfront and one near the MPL. The corner near the MLP has standing waves at 50-55... Sadly there is a wood door there. What can I do?
Maybe hang a panel on the door if you are willing to do that.
Try only one Sub, less is more sometimes ;) Well, unless you tried that already, lol.
@@TheeRocker you must know about Floyd toole
@@mladia Hi,,, a little yes, lol. One thing even though not knowing the size of the room, treated well or not, 3 subs is likely overkill. Adding to a compound problem. Add treatment, for one sub is a lot, but the room has 3. 2 Subs placed correctly in a treated room can work if done right in the right space. I gave a vague answer not knowing the intended mix purpose or situations.
Downloads are not working!!!
Just go to monophonic and be happy. Or, learn to live with the realities of stereo and be happy you aren't attempting to deal with 5.1, or 7.1, or....... lol!
For all the purists, you could test using two double-bass violins about 8 - 10 feet apart. Walk around and experience all kinds of fun low-frequency interactions.
Hi. If the bass vibrations are coming from neighbors above, will bass traps placed in my room help to dampen the vibrations too?
No. I found the best way to get rid of most annoying sound in general is just use good NC headphones where you can play your own silent relaxing music (or whatever you please). All low end problems dissapear also. And by far the cheapest solution, but still a compromise...
that is a problem of isolation and transmission loss criteria, not acoustic performance of a room
@@MacetazzOpina :(
Do you know of any solution for my case? It's giving me a headache
@@BrainHurricanes Unfortunately, this is a bass problem, where you "feel" the impact rather than "hear" it :(
@@marcpanther7924 4 Months later and still suffering ? You mean from the neighbours music right ? Only other thing is talk to your neigbours or the police, or move, or try to not get angry about it. If you can feel it surely a basstrap isn't going to do anything for you, i'm sorry. Something is bothering me also and I can't do anything about it, living in an appartment where the neighbours smoke on the balcony and when we want some fresh air to come in....
Thank you...again 👌🏼
Dear Jesco, Kudos for all the good work that you are doing. However, pl use some simple graphics where possible, they can be nicely hand-drawn too, but are needed for easier understanding. And last but the least - that halo light behind your head is really annoying and making me bipolar!
Does this mean that two subs are not ideal then?
Great video - as always. Thank you.
I have a question: Are standing waves independent of placement of the monitors and a sub, as they are a given by the room dimensions / frequency only? Or does the placement of the woofer create comb filters, and they influence the (fundamental) standing waves? Or are comb filters completely independent of the room standing waves? It's a question I'm struggling with for some time now Thanks a lot!
Not an expert (at all!) but my understanding of the comb filter effect he is talking about, is that it is an inherent issue BECAUSE you are using two seperate speakers to reproduce what is a "phantom" centre for the bass. Which is where we usually want the bass end to be. So i think you will find this effect even if you have two speakers set up in an open field, i.e. no room resonances or reflections at all. This is simple inherent in the physics when you use two speakers, which is why he said it wouldnt occur if you mixed in mono, with only one speaker.
Of course as soon as you set up your monitors in a room, then all the room modes with standing waves (resonances) due to the dimensions of the room, and the path reflections such as the floor, ceiling walls, these all conspire to make your problem worse. These you can mitigate to a certain extent, with good sound treatment, symmetrical but not parallel wall construction (which is fine if you are building a studio room literally from the ground up, but who has that kind of budget for a home studio?!?) and other bass taming constructions.
Bottom line, this is an irreducible issue, with two full range speakers. If you monitor with one sub, only for the entire bass end, and the rest of the frequency range by the stereo speakers, i would guess this might be the only way round this.
Anybody can correct me here? Just a guess on my part!
The modes ("standing waves") of the room are independent of any sourcing. Mathematically, they are solutions to an equation without a source term. They indicate that if you put energy into the room, and remove it, there will be a resulting pressure which will be some combination of the infinitly many modes; that combination will depend on how you put energy into the room and where. When you add a loudspeaker to the room, the placement (and type, meaning monopole vs dipole) will decide how much each mode will be excited. And where you put your ears relative to the excited modes will of course also be of importance. But with one or more loudspeakers actually sourcing the room, you will have an additional issue, and that is what is called SBIR (Speaker Boundary Interface Response) as the sound can take a direct path to your ears, but also be reflected off of the walls. Audioholics have a good video on this topic th-cam.com/video/eXfpAn3gkGs/w-d-xo.html.
what if a 3 way monitor was used?
It's not about the number of ways as much as the crossover points and the distance between the acoustic centers of the drivers. If you're really close to the speakers like in nearfield the best monitors are often 3 way but they are designed with really tight driver spacing and crossovers unlike a 12" 2-way PA speaker for example which is quite the opposite with high xovers and large drivers. In that case the 3-way ATC will be much better than the 2-way QSC in the nearfield in terms of coherency.
Yo can achieve that by using multiple subwoofers
It helps but it will almost never completely fix it in a small room.
You can achieve even bass across a couple feet with multiple subs. Not even close to even bass throughout the room. I've got duals, along with a NASTY dip at MLP around 55-70hz, then a minor null around 120. Even though I have duals (and really, really good subs from SVS), It took weeks of testing with REW, room correction, and about 30 different configurations, just to bring the null up a tiny bit. Meaning, its not a complete suck-out anymore. I can actually hear bass at 55hz...a little bit. But its not even close to even. Treating my room properly will help this out, but panels that help down to 50hz are 8-11" thick and very expensive.
I don't want to say it will be fixed, because it is what it is. It can't be fixed, just managed. If you have a cancelation because of comb filtering or whatever the case, adding a sub isn't just going to power through that cancelation. Each sub will help bring it back to life, just a little bit.
This is why people who have home theaters with multiple seating positions use 4 subs. For 1(or 2 very close) seating position(s), you can manage it with acoustics and dual subs, most likely.
Some rooms just suck. I know people who have built their home theaters and studios from the foundation to the studs to the treatments and even with 4 subs..the bass is not going to be the same in any 2 spots that are at least 3-4 feet away from each other.
In an echoic chamber the bass is the same volume everywhere
Multisub is amazing for this