Single 12" vs dual 10" subwoofers

[Koeitje]

So I am at the point where I can actually start adding a sub or subs to my setup. My room is about 38m2 with a 16m^2 listening area. Currently I have my speakers all the way at one end of the room up against the long wall, but I might be putting them on the short wall instead. Listening distance would be about the same, but I wouldn't have a wall behind my head in that case. Not sure if I can make it all fit (that short wall is slightly sloped, so its a bit of a struggle), but a quick measurement on the short wall showed that the massive 50hz peak was less extreme than on the long wall. The nulls were also less in that setup. I will have to confirm that with a more thorough measurement, because for this one I just moved one speaker a bit forward and turned it 90 degrees.

So my real question is how would one €1000 12" do versus two €500 10" subs? I don't need massive SPL output, but I want it to go low and tight and I have the capability to go for an opposite corner setup with dual subs. My gut says 12", but my brain says to just get 2 cheaper 10" subs. I will be pairing them with Revel M106's and I will probably plug the port on those so more of the low end will have to be played by the subs (does that make sense?).

Attached is a single measurement of one of my speakers (plugged port) at its current long wall position. The other channel shows similar peaks and nulls. Under 300hz I'm lacking so much output. How do I save this

 

[Kal Rubinson]

The advantage of two 10s over one 12 is that they can be placed to minimize modal interaction in the room. 3 or 4 is even better.

 

[Koeitje]

The advantage of two 10s over one 12 is that they can be placed to minimize modal interaction in the room. 3 or 4 is even better.

So in this case I would go for the dual 10", even if they are a quality level below the 12"?

 

[Kal Rubinson]

So in this case I would go for the dual 10", even if they are a quality level below the 12"?

I didn't say that since I don't know that. 10s are usually cheaper than 12s.

 

[Promit]

Generally speaking, multiples of a smaller sub are able to put out more bass but have less low extension than the larger woofer. In a room, the multiple subs are much more likely to provide a smooth and consistent response across the frequency range and across the seating area. For most practical purposes, you should get the 12" now if you think you'll be able to add another 12" down the road. Otherwise you'll have to sell both 10s and eat the loss to get two new 12s.

 

[detlev24]

So in this case I would go for the dual 10", even if they are a quality level below the 12"?

That generally depends on the products you are looking at - regarding their overall performance - and on your targeted application.

Since you list €-prices, I guess you are considering the EU market exclusively; right? No US import - that, at least, would not be possible at the total costs you mentioned.

I think it would be great to know which subwoofers you are trying to compare. Regarding multiple subwoofers, Harman has shown that this makes sense; but the benefit of 3 or 4, over 2 carefully placed subwoofers is not that big anymore. In short, multiple subwoofers likely will give you a higher combined output at lower distortion levels [vs. a single subwoofer of the same model]; and they allow for "filling of room modes" and thus for creation of a bigger sweet spot.

Of course, if you have just one fixed listening position with no spare seats, e.g., for friends (and if you are not after the combined boost in SPL), you might as well get equally happy with 1 subwoofer!

 

[detlev24]

[...] but have less low extension than the larger woofer. [...]

That is not necessarily the case, as a low(er) extension is just a matter of internal EQ, on active loudspeakers.

For instance, all Rythmik Audio subwoofer have basically the same frequency response; starting at well below 20 Hz in-room. Larger - or multiple - woofers will generally allow for a higher output at lower distortion levels, though.

 

[AudioJester]

The advantage of two 10s over one 12 is that they can be placed to minimize modal interaction in the room. 3 or 4 is even better.

I understand multiple bass sources can smooth out the room response. One thing I dont get about multiple subs, is they each localise above 80Hz, and hence need to be crossed over less than this.
So what do you do between 80-300Hz, considering there is much more content in this range and it looks just as bad as under 80Hz?

 

[Koeitje]

That generally depends on the products you are looking at - regarding their overall performance - and on your targeted application.

Since you list €-prices, I guess you are considering the EU market exclusively; right? No US import - that, at least, would not be possible at the total costs you mentioned.

I think it would be great to know which subwoofers you are trying to compare. Regarding multiple subwoofers, Harman has shown that this makes sense; but the benefit of 3 or 4, over 2 carefully placed subwoofers is not that big anymore. In short, multiple subwoofers likely will give you a higher combined output at lower distortion levels [vs. a single subwoofer of the same model]; and they allow for "filling of room modes" and thus for creation of a bigger sweet spot.

Of course, if you have just one fixed listening position with no spare seats, e.g., for friends (and if you are not after the combined boost in SPL), you might as well get equally happy with 1 subwoofer!

Its Europe yes, and currently I am eyeballing dual KEF 10B's or a single SB2000. The KEFs will be a little bit more expensive, but the SB2000 will also force me to buy a source with enough line level outputs while I would use the KEFs high-level inputs. Looking at these because the KEFs have some basic DSP control and the SB2000 has even better DSP. Dual SB1000's are also on the table, thats 2x12" but no DSP at all. In the future I want full DIRAC or something else, but that is a long term thing.

I don't need extreme SPL levels, my M106's wont handle that anyway. The 10B's peak at 110dB+ according to the specs, my Revel's will be up in smoke long before that .

I understand multiple bass sources can smooth out the room response. One thing I dont get about multiple subs, is they each localise above 80Hz, and hence need to be crossed over less than this.
So what do you do between 80-300Hz, considering there is much more content in this range and it looks just as bad as under 80Hz?

You make a good point, because it seems I would need to cross them higher than ideal....I will do some proper measurements tomorrow. What could be the cause of the low output below 300hz? Is my room really nulling so much?

 

[Promit]

That is not necessarily the case, as a low(er) extension is just a matter of internal EQ, on active loudspeakers.

For instance, all Rythmik Audio subwoofer have basically the same frequency response; starting at well below 20 Hz in-room. Larger - or multiple - woofers will generally allow for a higher output at lower distortion levels, though.

You can EQ whatever you want, until you run out of power or Xmax. And "In-room" is a weasel word for "we added a low shelf boost to the response curve". There are many design parameters to consider, as seen in PSA 18" subs that distinctly do not have that subsonic authority (owing to pro style woofers and undersize cabinets). But in most cases, people are comparing similar system designs at similar price points and the generalization is a good rule of thumb.

 

[detlev24]

I understand multiple bass sources can smooth out the room response. One thing I dont get about multiple subs, is they each localise above 80Hz, and hence need to be crossed over less than this.
So what do you do between 80-300Hz, considering there is much more content in this range and it looks just as bad as under 80Hz?

Actually, frequencies up to 100 Hz do still follow an omnidirectional dispersion pattern; 80 Hz has just become the "standard reference" crossover frequency.

Just recently, part of your question has been discussed here. Above 100 Hz, if we talk about room modes, (early) reflections etc.: The best thing you can do is to apply proper acoustic room treatment. However, digital room correction - manually with REW; or semi-automatic with Dirac Live etc. - will most likely be able to smoothen the frequency response to an enjoyable level; even without any acoustic treatment in place. So, this is basically what can be done provided, that you already have found the most feasible setup in your room.

But note, there are certain limitations an EQ cannot fix. Again, proper acoustic room treatment would be the first choice; and room EQ can always be applied thereafter, for further fine-tuning.

 

[Kal Rubinson]

Generally speaking, multiples of a smaller sub are able to put out more bass but have less low extension than the larger woofer.

Sure but I am using a 10" sub with useful in-room response below 15Hz. Multiples of them do just fine for me.

 

[Kal Rubinson]

I understand multiple bass sources can smooth out the room response. One thing I dont get about multiple subs, is they each localise above 80Hz, and hence need to be crossed over less than this.

If they are all producing the same signal, they are less localizable as an ensemble.

So what do you do between 80-300Hz, considering there is much more content in this range and it looks just as bad as under 80Hz?

I have regular speakers for that range.

 

[Wes]

this may help some who are trying to understand modal or smoothness comments above:

https://en.wikipedia.org/wiki/Standing_wave

 

[detlev24]

[...] I don't need extreme SPL levels, my M106's wont handle that anyway. The 10B's peak at 110dB+ according to the specs, my Revel's will be up in smoke long before that .

[...] What could be the cause of the low output below 300hz? Is my room really nulling so much?

Ideally, you would find the best integration in your room - for (a) subwoofer/s with the M106 - as briefly mentioned here [same link as before]. Hence, by crossing-over with the subwoofer(s), the M106 would not require to play that deep anymore and much more headroom would become available - in short: they would be able to safely exceed the manufacturer's rated maximum SPL.

Furthermore, our hearing is non-linear. See: Interactive Ear Sensitivity Chart from Independent Recording Network. The threshold of hearing a 20 Hz tone lies at ~75 dB SPL, which is the equivalent of "hearing" a ~2 kHz tone at 0 dB SPL. Thus, you might want to consider higher output capabilities at lower frequencies.

Hard to say without further information; regarding the "low output below 300 Hz". Re-arranging your setup, loudspeakers and/or listening position(s) in your room, might help.

====
Do I understand correctly, that you would require a subwoofer with high-level input? Especially in this case, within Europe, you might want to consider BK Electronics - manufacturer distribution, exclusively: better prices and great configuration(s).

 

[Koeitje]

Ideally, you would find the best integration in your room - for (a) subwoofer/s with the M106 - as briefly mentioned here [same link as before]. Hence, by crossing-over with the subwoofer(s), the M106 would not require to play that deep anymore and much more headroom would become available - in short: they would be able to safely exceed the manufacturer's rated maximum SPL.

Furthermore, our hearing is non-linear. See: Interactive Ear Sensitivity Chart from Independent Recording Network. The threshold of hearing a 20 Hz tone lies at ~75 dB SPL, which is the equivalent of "hearing" a ~2 kHz tone at 0 dB SPL. Thus, you might want to consider higher output capabilities at lower frequencies.

Hard to say without further information; regarding the "low output below 300 Hz". Re-arranging your setup, loudspeakers and/or listening position(s) in your room, might help.

====
Do I understand correctly, that you would require a subwoofer with high-level input? Especially in this case, within Europe, you might want to consider BK Electronics - manufacturer distribution, exclusively: better prices and great configuration(s).

in the future I want to actually cross-over my M106's, but that's a long term project. What I can do for now is close the port, that should at least stop the woofer from over-exerting itself.

I'm not a big fan of BK because they have zero build in equalisation, which would be practical in my current situation. But yeah, I need to use high level connections. If I need low level I'd have to change my source.

 

[detlev24]

What do you mean by "they have zero built-in equalisation"? Would the backside controls not allow for a decent integration with a higher flexibility, than many other manufacturers offer? Especially the variable phase control is of interest; vs. just a 0° or 180° switch. // On high-level input you have fewer tuning possibilities, anyways.


[ Additional picture from avforums. ]

Just to be clear: A higher crossover frequency than 100 Hz can be chosen in case of tiny satellite loudspeakers or small center/surround/bookshelf loudspeakers; provided the subwoofer(s) do(es) cover the "higher" frequency range as required. This might diminish flexibility of subwoofer placement, though, since above 100 Hz, the subwoofer(s) might become localizable more easily. Hence, in this scenario, a subwoofer placement in close proximity to the crossed-over loudspeaker(s) would probably be preferred.

[ EDIT ]
I see what you have been referring to, regarding built-in EQ. Following, some 'KEF Kube 10b' measurements, taken from LowBeats. Again, a variable phase control is much more crucial for a seamless subwoofer integration and I personally would prefer to have a more even frequency response at much lower distortion levels; which any BK subwoofer should provide.

EQ
Low-pass
Distortion

 

[georgeT]

I'm inclined to believe this guy

One big, properly placed sub, with proper room treatment is better than multiple small subs. But if you can't place your sub where it needs to be and you can't manage room modes then multiple subs will help while probably being more expensive.

 

[detlev24]

[...] One big, properly placed sub, with proper room treatment is better than multiple small subs. But if you can't place your sub where it needs to be and you can't manage room modes then multiple subs will help while probably being more expensive.

Further, much more precise information on that topic can be found there:

Bass Trap Myths

 

[tifune]

There are many design parameters to consider, as seen in PSA 18" subs that distinctly do not have that subsonic authority (owing to pro style woofers and undersize cabinets).

Can you tell me a little more about that? Considering 2x PSA 15" sealed units, honestly just because they're downfiring and that's a good solution for my situation (a living room where kids have fast paced adventures all day).

The opposition is an on-sale monstrous Monoprice 15" which is easily capable of producing the volume/extension I need but I only have 1 corner I can safely place it vs being able to put 2x downfiring units anywhere that wires will allow. Mixed use music/movies