Answered Do I need dual subs in my 2.1 system?

BarKohba

Active Member
Hi

I've got a yamaha 2.1 system im rreally happy with: 803D stereo receiver, B750 bookshelves and an SW700 sub. I've finished srtting it up and tweaking it after almost 2 days, crossover at 80hz, yamaha's ypao (room correction dsp) done, everything is really beautifully blended in and I can't locate the sub with my ears - it's "invisible" as it should be.

However i've been reading and seeing on youtube that dual subs is the way to go - somehow the bass is better, etc.

I dont need -more- bass at all, but I'm wondering if adding another sub (making my system a 2.2) would benefit my setup in any way considering the single sub i have is very well integrated?
 

BlueWizard

Distinguished Member
Not that this is my area of expertise, but Dual Subs give a more uniform distribution of sound in the room with fewer hot-stops and nulls.

Whether is would benefit you is another matter. That is going to hinge on the size and layout of the room, and the general acoustics, and whether this is a Music System or a Movie System.

If you have a good blend now, then I would just go with it.

Or if you could perhaps get a friend to bring his Sub over so you can try the pair.

Steve/bluewizard
 

BarKohba

Active Member
Im using it mostly for music. Dont have a friend with a sub unfortunately, was just wondering if someone here has experimented with such a system for music and had benefits
 

larkone

Distinguished Member
Two subs are twice as hard to balance correctly unless you are using some sort of room correction that will do it for you.
 

BlueWizard

Distinguished Member
Two subs are twice as hard to balance correctly unless you are using some sort of room correction that will do it for you.

He does have an Amp with Room Correction (Yamaha RN803D). And while I agree that two Subs are harder, I won't go so far as to say Twice as hard.

But, the key factors are the room itself, how much space is available to place the Subs, and where the equipment is placed in the room. In a very small room with limited space, there is no need for a second Sub, and in fact it probably just complicates things.

Given that this is a music system, a given that the Original Poster is pretty satisfied with things the way they are now, I'm inclined to say - stick with what you have.

The goal is very different between Movies and Music, though a bit simplistic, for Movies you want Chest Kickers that serve the LFE-Channel in the movie sound track. So the more Subs and the more air you push, the greater the impact.

But, for Music, in my opinion, the goal is very different. The goal is not to kick you in the chest, but rather to seamlessly and perfect blend with your Front Speakers. To blend so seamlessly with the Front that there is no distinction between them, the Subs just become an extension of the Front Speakers.

But a lot of factors effect the ability to do that - Room Size, Speakers Placement, Bass Management, the type of Sub chosen, and other factors. It seems to me, again in my opinion, that the blending of Front and Sub in a Music system is more subtle and refined than in a Movie system.

So, it would seem, the determining factors in whether a second Sub would work are all in factors that we currently don't know. They are all in very fine details of the room and system.

It seems as if a Single Sub is working well for the OP. If he senses no directionality from the Sub, that is, the bass is coming from over there, then he has achieved his goal.

If he does sense some degree of directionality, then perhaps lower the Sub Crossover by 5 or 10hz.

But then ...that's just my opinion.

Steve/bluewizard
 
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BarKohba

Active Member
He does have an Amp with Room Correction (Yamaha RN803D). And while I agree that two Subs are harder, I won't go so far as to say Twice as hard.

But, the key factors are the room itself, how much space is available to place the Subs, and where the equipment is placed in the room. In a very small room with limited space, there is no need for a second Sub, and in fact it probably just complicates things.

Given that this is a music system, a given that the Original Poster is pretty satisfied with things the way they are now, I'm inclined to say - stick with what you have.

The goal is very different between Movies and Music, though a bit simplistic, for Movies you want Chest Kickers that serve the LFE-Channel in the movie sound track. So the more Subs and the more air you push, the greater the impact.

But, for Music, in my opinion, the goal is very different. The goal is not to kick you in the chest, but rather to seamlessly and perfect blend with your Front Speakers. To blend so seamlessly with the Front that there is no distinction between them, the Subs just become an extension of the Front Speakers.

But a lot of factors effect the ability to do that, Room Size, Speakers Placement, Bass Management, the type of Sub chosen, and other factors. It seems to me, again in my opinion, that the blending of Front and Sub in a Music system is more subtle and refined than in a Movie system.

So, it would seem, the determining factors in whether a second Sub would work are all in factors that we currently don't know. They are all in very fine details of the room and system.

It seems as if a Single Sub is working well for the OP. If he senses no directionality from the Sub, that is, the bass is coming from over there, then he has achieved his goal.

If he does sense some degree of directionality, then perhaps lower the Sub Crossover by 5 or 10hz.

But then ...that's just my opinion.

Steve/bluewizard

I guess the issue i was thinking about is even though im 100% satisfied, you never know "better" until you get to hear it. So I was wondering in general if it would benefit any audio system by a sensible amount as far as sq goes (2.2 vs 2.1, where the 2.1 is nicely blended and there are no comprimises).

Think of it as a speaker upgrade - would it be any effect like that, addadd a 2nd sub?

Im the meantime i found some songs that had certain bass notes where the sub was actually pulling attention to itself. As the yamaha crossover processor only jumps in increments of 20h, I switched the crossover to 60hz (my speakers are rated at about 45hz @ -10db), and bumped up the sub by about 3db. (For) now it's perfectly integrated.
 

BlueWizard

Distinguished Member
I guess the issue i was thinking about is even though im 100% satisfied, you never know "better" until you get to hear it. So I was wondering in general if it would benefit any audio system by a sensible amount as far as sq goes (2.2 vs 2.1, where the 2.1 is nicely blended and there are no compromises).

....

Again, the Devil is in the details, we would need Intimate information about your specific room and the placement within the room to make any kind of recommendations.

The problem is that most discussion of Dual or Multiple Subs are about Movie Surround Systems. So, it is hard to transfer that discussion to Music systems.

If you have enough space, sufficient space that you have a degree of flexibility in placing the Subs, then perhaps you can gain something.

For myself, in a pure Stereo system, I have often considered Dual Stereo Subs, but rather than one or two large Subs, I would be more inclined to go with two Smaller Subs, probably 10" but perhaps in the right circumstances two 8". Keep in mind while I want deeper bass, for Music, especially for my music, I don't need 20hz or Sub-20hz bass. If I can drag it down smoothly to 25hz with Drivers similar or slightly larger than the drivers on my main Front speakers, I'm good.

In reality, the only thing I can think of that does Sub-30hz in Music would be Pipe Organs, then we have to ask, even if you are listening to a Pipe Organ, how often are they really hitting those lowest of the low notes?

So, if I can go Sub-30hz, fine, but I don't need to go much lower. In my own experience with two speakers having 2x8" each and rated at 28hz, when I played 28hz tones, I did not hear a tone, rather I simply heard the Fuff-Fuff-Fuff of the driver moving. Again, the point being that while Sub-30hz is nice, I don't need to go all that much below it for the music I commonly listen to.

Also, let's say you use 2x12" Subs in a reasonable sized but still modest room, just the volume of air creates a degree of impact. I would be worried that no matter how low I functionally turned the Subs down, they would still push so much air in the room, that they would stand out from the Front speakers.

So, like I said, probably two 10" would not be grossly bigger than the speakers I'm likely to have, and with the right 8" Sub, perhaps even two 8" would do.

The key is that buy pushing some of the bass weight off onto the Sub, you are making the job of the Front that much easier, and pushing the bass off on to the Sub, I speculate, would likely clear up the Front Speakers nicely.

You can see how much more complex this is for a pure Music system.

In your system, the Yamaha NS-B750 Bookshelf Speakers are not cheap, but they are a 5" (130mm) 2-way. The Yamaha SW700 is a 10" (300w, 20hz) Sub, that seems like a very nice blend, and those should compliment each other nicely.

NS-B750 - Speakers - Yamaha - Australia

NS-SW700 - Subwoofers - Yamaha Australia

Sorry to use Australia, but it was the first reference that came up on a Search.

If by chance you decide to try TWO Subs, I would either get another SW700 or get two New Subs.

Though again, it sounds like you have a very nice blend of the system you have now. I'm not sure it needs improvement.

Curious, there must be some type of Calibration/Setup program in the RN803, what did it choose for the Sub/Front Crossover? The Calibration/Setup Program actually measures the room and sets things accordingly.

Also, have you run Room EQ with the system?

Steve/bluewizard
 

BarKohba

Active Member
Again, the Devil is in the details, we would need Intimate information about your specific room and the placement within the room to make any kind of recommendations.

The problem is that most discussion of Dual or Multiple Subs are about Movie Surround Systems. So, it is hard to transfer that discussion to Music systems.

If you have enough space, sufficient space that you have a degree of flexibility in placing the Subs, then perhaps you can gain something.

For myself, in a pure Stereo system, I have often considered Dual Stereo Subs, but rather than one or two large Subs, I would be more inclined to go with two Smaller Subs, probably 10" but perhaps in the right circumstances two 8". Keep in mind while I want deeper bass, for Music, especially for my music, I don't need 20hz or Sub-20hz bass. If I can drag it down smoothly to 25hz with Drivers similar or slightly larger than the drivers on my main Front speakers, I'm good.

In reality, the only thing I can think of that does Sub-30hz in Music would be Pipe Organs, then we have to ask, even if you are listening to a Pipe Organ, how often are they really hitting those lowest of the low notes?

So, if I can go Sub-30hz, fine, but I don't need to go much lower. In my own experience with two speakers having 2x8" each and rated at 28hz, when I played 28hz tones, I did not hear a tone, rather I simply heard the Fuff-Fuff-Fuff of the driver moving. Again, the point being that while Sub-30hz is nice, I don't need to go all that much below it for the music I commonly listen to.

Also, let's say you use 2x12" Subs in a reasonable sized but still modest room, just the volume of air creates a degree of impact. I would be worried that no matter how low I functionally turned the Subs down, they would still push so much air in the room, that they would stand out from the Front speakers.

So, like I said, probably two 10" would not be grossly bigger than the speakers I'm likely to have, and with the right 8" Sub, perhaps even two 8" would do.

The key is that buy pushing some of the bass weight off onto the Sub, you are making the job of the Front that much easier, and pushing the bass off on to the Sub, I speculate, would likely clear up the Front Speakers nicely.

You can see how much more complex this is for a pure Music system.

In your system, the Yamaha NS-B750 Bookshelf Speakers are not cheap, but they are a 5" (130mm) 2-way. The Yamaha SW700 is a 10" (300w, 20hz) Sub, that seems like a very nice blend, and those should compliment each other nicely.

NS-B750 - Speakers - Yamaha - Australia

NS-SW700 - Subwoofers - Yamaha Australia

Sorry to use Australia, but it was the first reference that came up on a Search.

If by chance you decide to try TWO Subs, I would either get another SW700 or get two New Subs.

Though again, it sounds like you have a very nice blend of the system you have now. I'm not sure it needs improvement.

Curious, there must be some type of Calibration/Setup program in the RN803, what did it choose for the Sub/Front Crossover? The Calibration/Setup Program actually measures the room and sets things accordingly.

Also, have you run Room EQ with the system?

Steve/bluewizard

I havent ran room eq - not sure what that is.

The yamaha calibration is called YPAO and it uses a mic. After calibrating, I was 90% pleases with the result. It set the speaker output to low cut (as it should, as opposed to full range which is the other option) and the cut was at 80hz. I was very happy with it but there still are some areas of some tracks that pull attention towards the sub - so I went with 60hz to solve this (here, having 2 subs would let me use 80hz with no problem).

It also set the sub output to -9db / -10db. Basically the instructions are to set the volume on medium on the sub, and the receiver decides anuwhere from -10 to +10db. And -9 worked perfect fot 80hz, but after setting it at 60hz i went to -4.5db to get the correct resuult (for my ears).

It also takes into account the speaker distance, which was mostly correct besides the sub which was set 20cm further, but that actually made it sound tighter.

As for eq - it applies an eq setting which i dnt like - very little bass which made the sound very thin, and theres also "ypao volume" which is actually a loudness eq - very helpful for watching movies at night, thats when i activate it.
 

Don Dadda

Distinguished Member
I guess the issue i was thinking about is even though im 100% satisfied, you never know "better" until you get to hear it.

True but also Curiosity killed the cat. So If it ain’t broke, don’t try fix it.
 

BarKohba

Active Member
I just researched the multi sub subject a bit more.

Considering one has the subs crossed over from 60hz, which is basically an almost completely non directional sub bass band - why would there ever be an advantage for using dual subs (besides the cases where your listening room is a giant one and one sub just can't handle filling the space) when all they are doing is reproducing a non directional sound that can't be located and therefore basically isn't even stereo, or at least having 2 sources produce these same frequency would (to my mind) add nothing due to the sound's non-stereo, non-directional nature?

Did I get this right or am I missing something, and there actually is a pretty good advantage in using 2 subs for 20-60hz reproduction?
 

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