Stereo speakers with or without subwoofer for mixing and mastering

[Teon]

Hello to the community, I hope that you all are having a great start of the week. I have a question regarding using a subwoofer for mixing,

Let’s imagine two setup scenarios:

Setup #1: We have a L and R channel and the speakers reproduce the entire available frequency range in Stereo. No subwoofer is used in this case

Setup #2: We have a L and R and a Single subwoofer that has a X-over(crossover) frequency of let’s say 80 Hz. This setup will reproduce the frequencies above 80 Hz through the L and R speakers, and will play the frequencies below 80 Hz through the single subwoofer. Basically above 80 Hz is Stereo, but below 80 Hz (essentially bass) will be in Mono.

Below are my questions:

1-What are the pros and cons of each setup if mixing and later translation to both “stereo with subwoofer” and “stereo without subwoofer” is the main priority?

2-Now I am aware that bass is omni-directional but I have also read on one of the threads that all frequencies are omni-directional. Is this correct? (Please educate me on this point.)

3-What are your thoughts on which setup is better for mixing? What will be your approach? How does each setup affect what we hear?

4-What are your thoughts on a setup that uses L and R speakers with two subwoofers? Are there any benefits? Pros and Cons? (basically below 80 Hz will also be stereo.)

I appreciate the time you put into reading and answering to this.

Thanks in advance to the wonderful community,

Teon

 

[Purité Audio]

If you have ‘full-range’ loudspeakers they you don’t have the hassle of properly integrating subs which with traditional designs requires some form of processor/filtering.
Keith

 

[Teon]

If you have ‘full-range’ loudspeakers they you don’t have the hassle of properly integrating subs which with traditional designs requires some form of processor/filtering.
Keith

Thank you for you reply, but this does not answer any of the questions mentioned above. More details in your answer are greatly appreciated

 

[Purité Audio]

Bass below 80Hz is omni-directional, there ‘shouldn’t’ be too much difference if the subs are properly integrated.
But to have full range traditional designs you are looking at really big enclosures ( with a minimum required listening distance) or small mains and subs or look at more contemporary designs which are full-range , relatively compact and can be sited close.
As to which is best that would be your preference.
Keith

 

[Ellebob]

1. The best location for bass is rarely the same location for mids and highs.

2. In theory that is true that sound will radiate in all directions but in reality it is not true due to the different wavelength sizes. If we're using a 80 Hertz crossover the bass waves are between 14 ft at 80 HZ and about 56 ft long at 20 HZ. So the speaker which we will say is only about a foot big for typical bookshelf has no effect on these larger waves. As we go higher in frequency and waves are only inches long more sound is radiated in front of the speaker then behind it. Some sound still goes behind it, that's why if he had a speaker in a field playing a higher frequency and you stand behind the speaker you can still hear it. Just not as loud as if you if you were in front of it. Anyway, smaller waves we can localize. If we are localizing bass it's usually because the bass is causing other resonances at higher frequencies.

3. I would always go with a sub, the disadvantage is it can be tougher to set up and integrate with the mains. Plus mains typically need to be pretty large to play the lower octaves. Most speakers that are that large and you're using them in a near field environment you will not get the combined sound of all the drivers.

4. You won't hear stereo bass. A 14-ft wavelength hits both ears at the same time, we don't know where it's coming from. Usually, when the quarter wavelength gets to be closer to our head size that's when we can localize. This is typically closer to 160HZ give or take. 80hz is used because it is roughly half that and some lower male vocals begin at just over ~100hz (like James Earl Jones) so we like all the vocals from the speakers.

Multiple subs is talked about a lot but it is used for different purpose and not stereo bass. For mixing if you are only listening in one spot two or more subs are not necessary. Two or more subs are used to get the same or similar bass response in multiple seats. If you only care about one seat, you put that seat in a good location, put the sub in a good location and then you equalize the sub. Whether using one or multiple subs EQ is needed.
Hardest part about doing this is realizing to get the best sound your room needs to be set up where it is best for your speakers, sub and seating. Most people place everything where it's convenient and not for the best sound. Sometimes, using two subs will help to get a better bass response if your seat is not in a good location.
When taking classes on acoustics there is one common theme. Just like real estate it is all about location, location, location and location.
Location of seating, location of speakers, location of sub(s), location of acoustic treatments. Seating is first on the list!

 

[Oddball]

The first question is what max SPL you will try to achieve at MLP. The second is what frequency response you are targeting. There is no specific cut off point for "stereo" and depends on the material/artist/producer.

This might give you a clue how powerful full range mains you would need. In general, solid 1kW subs with 12" or larger drivers would play louder and with less distortion from 50-60-ish hz (to be generous) compared with capable towers with multiple 8" or larger drivers even if you have large amps on towers. If the full range towers could not meet your requirements or would be too expensive, perhaps the subs are the only practical solution.

 

[Teon]

1. The best location for bass is rarely the same location for mids and highs.

2. In theory that is true that sound will radiate in all directions but in reality it is not true due to the different wavelength sizes. If we're using a 80 Hertz crossover the bass waves are between 14 ft at 80 HZ and about 56 ft long at 20 HZ. So the speaker which we will say is only about a foot big for typical bookshelf has no effect on these larger waves. As we go higher in frequency and waves are only inches long more sound is radiated in front of the speaker then behind it. Some sound still goes behind it, that's why if he had a speaker in a field playing a higher frequency and you stand behind the speaker you can still hear it. Just not as loud as if you if you were in front of it. Anyway, smaller waves we can localize. If we are localizing bass it's usually because the bass is causing other resonances at higher frequencies.

3. I would always go with a sub, the disadvantage is it can be tougher to set up and integrate with the mains. Plus mains typically need to be pretty large to play the lower octaves. Most speakers that are that large and you're using them in a near field environment you will not get the combined sound of all the drivers.

4. You won't hear stereo bass. A 14-ft wavelength hits both ears at the same time, we don't know where it's coming from. Usually, when the quarter wavelength gets to be closer to our head size that's when we can localize. This is typically closer to 160HZ give or take. 80hz is used because it is roughly half that and some lower male vocals begin at just over ~100hz (like James Earl Jones) so we like all the vocals from the speakers.

Multiple subs is talked about a lot but it is used for different purpose and not stereo bass. For mixing if you are only listening in one spot two or more subs are not necessary. Two or more subs are used to get the same or similar bass response in multiple seats. If you only care about one seat, you put that seat in a good location, put the sub in a good location and then you equalize the sub. Whether using one or multiple subs EQ is needed.
Hardest part about doing this is realizing to get the best sound your room needs to be set up where it is best for your speakers, sub and seating. Most people place everything where it's convenient and not for the best sound. Sometimes, using two subs will help to get a better bass response if your seat is not in a good location.
When taking classes on acoustics there is one common theme. Just like real estate it is all about location, location, location and location.
Location of seating, location of speakers, location of sub(s), location of acoustic treatments. Seating is first on the list!

Thanks for your feedback,

You mentioned that “ If we're using a 80 Hertz crossover the bass waves are between 14 ft at 80 HZ and about 56 ft long at 20 HZ. So the speaker which we will say is only about a foot big for typical bookshelf has no effect on these larger waves.”

I don’t think I fully understand this, could you give an example of a scenario that a foot big speaker “has” an effect on the sound waves? What kind of effect are we talking about in here?

 

[sigbergaudio]

Hello to the community, I hope that you all are having a great start of the week. I have a question regarding using a subwoofer for mixing,

Let’s imagine two setup scenarios:

Setup #1: We have a L and R channel and the speakers reproduce the entire available frequency range in Stereo. No subwoofer is used in this case

Setup #2: We have a L and R and a Single subwoofer that has a X-over(crossover) frequency of let’s say 80 Hz. This setup will reproduce the frequencies above 80 Hz through the L and R speakers, and will play the frequencies below 80 Hz through the single subwoofer. Basically above 80 Hz is Stereo, but below 80 Hz (essentially bass) will be in Mono.

Below are my questions:

1-What are the pros and cons of each setup if mixing and later translation to both “stereo with subwoofer” and “stereo without subwoofer” is the main priority?

2-Now I am aware that bass is omni-directional but I have also read on one of the threads that all frequencies are omni-directional. Is this correct? (Please educate me on this point.)

3-What are your thoughts on which setup is better for mixing? What will be your approach? How does each setup affect what we hear?

4-What are your thoughts on a setup that uses L and R speakers with two subwoofers? Are there any benefits? Pros and Cons? (basically below 80 Hz will also be stereo.)

I appreciate the time you put into reading and answering to this.

Thanks in advance to the wonderful community,

Teon

1. I am biased as we are a manufacturer of speaker systems with integrated subs. But as long as properly setup, both variations will work well, but a setup with subwoofer is likely to have better bass capacity and lower frequency response.

2. For practical purposes / in this context, the answer is no. From traditional speakers, the frequencies are omnidirectional up to 100-200hz, and they become increasingly directional as frequency increases.

3. As mentioned in point 1, both can sound good and similar and correct if properly setup.

4. This will give you better capacity, more even frequency response and potentially slightly better stereo cues if the subwoofers are crossed high. In practice it is however very hard to hear where the sound is coming from below 80hz. And you are likely to mix most sound below 80hz in mono anyway?

 

[NTK]

I don’t think I fully understand this, could you give an example of a scenario that a foot big speaker “has” an effect on the sound waves? What kind of effect are we talking about in here?

It is from the the physics of sound wave propagation. Sound waves "bend" around corners due to an effect called diffraction. The amount of diffraction is related to the wavelength of the wave, the size, and shape of the object (how sharp the corner is). Below are two screenshots from simulations of a radiating source "blocked" by a box to approximate a subwoofer.

https://falstad.com/ripple/

The first one is low frequency, and the wavelength of the sound wave is a few times that of the dimensions of the box. The sound wave generated diffracts around the box and the radiation pattern is near spherical. The second one is at a higher frequency where the wavelength is a fraction of the box dimensions, and the sound wave "beams" toward the front.

If we have a subwoofer that is a 1.5 ft cube, at 80 Hz, the wavelength will be ~9 times the box dimensions, which looks like it is even a bit higher than what is shown in the first figure.

 

[Teon]

It is from the the physics of sound wave propagation. Sound waves "bend" around corners due to an effect called diffraction. The amount of diffraction is related to the wavelength of the wave, the size, and shape of the object (how sharp the corner is). Below are two screenshots from simulations of a radiating source "blocked" by a box to approximate a subwoofer.

https://falstad.com/ripple/

View attachment 389950View attachment 389951
The first one is low frequency, and the wavelength of the sound wave is a few times that of the dimensions of the box. The sound wave generated diffracts around the box and the radiation pattern is near spherical. The second one is at a higher frequency where the wavelength is a fraction of the box dimensions, and the sound wave "beams" toward the front.

If we have a subwoofer that is a 1.5 ft cube, at 80 Hz, the wavelength will be ~9 times the box dimensions, which looks like it is even a bit higher than what is shown in the first figure.

Are the two figures basically showing the box of a subwoofer enclosure? If so, shouldn’t the soundwaves be starting from the surface of the driver and not from inside the enclosure?

 

[NTK]

Are the two figures basically showing the box of a subwoofer enclosure? If so, shouldn’t the soundwaves be starting from the surface of the driver and not from inside the enclosure?

The simulation is done with a source (in this case a short line source) placed in front of a box. See the 2 little squares, they are the end-points of the line source.

 

[Multicore]

Sound On Sound podcast recently talked about setting up a home studio. They said home studio rooms are usually small and never have enough bass absorption so don't use speakers bigger than 6" and if you really have to have a sub to rock the vibe, don't use it when mixing.

Setting Up A Home Studio | SOS Podcast

Paul White and Hugh Robjohns discuss the basics of a good home studio setup, including choosing the right equipment and setting up your space correctly to achieve the best recording and mixing results.

www.soundonsound.com

 

[sigbergaudio]

Sound On Sound podcast recently talked about setting up a home studio. They said home studio rooms are usually small and never have enough bass absorption so don't use speakers bigger than 6" and if you really have to have a sub to rock the vibe, don't use it when mixing.

Setting Up A Home Studio | SOS Podcast

Paul White and Hugh Robjohns discuss the basics of a good home studio setup, including choosing the right equipment and setting up your space correctly to achieve the best recording and mixing results.

www.soundonsound.com

If that is correctly represented, that sounds like silly advice. But it is a fact that you can't just throw in a sub without ensuring the response is even. But you may get many of the same issues in the bass even with a 6" monitor, so..

 

[Multicore]

If that is correctly represented, that sounds like silly advice. But it is a fact that you can't just throw in a sub without ensuring the response is even. But you may get many of the same issues in the bass even with a 6" monitor, so..

The entire podcast didn't mention room correction EQ. It did mention room modes and typical dimensions of rooms that people use for home studios. They recommended using headphones to mix if the music has lots of bass and you don't have enough bass traps, which you probably don't.

I thought it was an interesting counterpoint to what we usually get here on ASR where most people want m o a r bass.

 

[sigbergaudio]

The entire podcast didn't mention room correction EQ. It did mention room modes and typical dimensions of rooms that people use for home studios. They recommended using headphones to mix if the music has lots of bass and you don't have enough bass traps, which you probably don't.

I thought it was an interesting counterpoint to what we usually get here on ASR where most people want m o a r bass.

I would assume you sit in a pretty fixed position when mixing music, then you can correct pretty well for room modes with EQ.

 

[Ellebob]

Thanks for your feedback,

You mentioned that “ If we're using a 80 Hertz crossover the bass waves are between 14 ft at 80 HZ and about 56 ft long at 20 HZ. So the speaker which we will say is only about a foot big for typical bookshelf has no effect on these larger waves.”

I don’t think I fully understand this, could you give an example of a scenario that a foot big speaker “has” an effect on the sound waves? What kind of effect are we talking about in here?

I think NTK tried to show this with the graphic. Let me see if I can explain this better.
Imagine a tennis ball sized rock dropped in a pond and you see the wave travel equally in all directions away from the rock. Making nice circles going away from the rock Now place a box in the water with part of the box sticking out of the water. Drop the rock again. Do you get the nice circles around the rock? No, some of the waves bounce off the box. So more waves go towards the side the rock was dropped and less behind the box. This is similar to higher frequencies coming out of a speaker. Much of sound go forwards and not behind the speaker.
Now let's drop a boulder the size of car next to the box. This time the wave is so big it goes right over the box and it looks like those circles again. Like the box was not even there and you can hear sound equally well behind the speaker with bass.
Hopefully, this explains a little better.

 

[Teon]

I think NTK tried to show this with the graphic. Let me see if I can explain this better.
Imagine a tennis ball sized rock dropped in a pond and you see the wave travel equally in all directions away from the rock. Making nice circles going away from the rock Now place a box in the water with part of the box sticking out of the water. Drop the rock again. Do you get the nice circles around the rock? No, some of the waves bounce off the box. So more waves go towards the side the rock was dropped and less behind the box. This is similar to higher frequencies coming out of a speaker. Much of sound go forwards and not behind the speaker.
Now let's drop a boulder the size of car next to the box. This time the wave is so big it goes right over the box and it looks like those circles again. Like the box was not even there and you can hear sound equally well behind the speaker with bass.
Hopefully, this explains a little better.

If I understood correctly, you mean we place a hollow box in the water and we drop the water in the part of the water surrounded by the box walls, is that correct?

 

[sigbergaudio]

@Teon Perhaps it's easier to see visually how frequencies spread from a speaker? Below is what is called a horizontal polar map from a traditional speaker enclosure. On the x-axis you have frequency, and on the y-axis you have degrees (implying sound measurement from different angles around the speaker). The colors are energy. As you can see, the lower in frequency you get, the more evenly spread the energy is all around the speaker, while when you move up in frequency, the energy is reduced as you move towards the side and back of the speaker.

 

[Teon]

@Teon Perhaps it's easier to see visually how frequencies spread from a speaker? Below is what is called a horizontal polar map from a traditional speaker enclosure. On the x-axis you have frequency, and on the y-axis you have degrees (implying sound measurement from different angles around the speaker). The colors are energy. As you can see, the lower in frequency you get, the more evenly spread the energy is all around the speaker, while when you move up in frequency, the energy is reduced as you move towards the side and back of the speaker.

View attachment 390032

I have a hard time visualizing how the measurement angle of the microphone will look in real life. Could you provide some photos please?

Also, the graph shows how the frequencies spread from a speaker, but from which surface of the speaker? Is this graph showing the woofer/tweeter spread, back of the speaker, too etc.?

 

[Purité Audio]

Worth a look.
Keith