Single 12" vs dual 10" subwoofers

[watchnerd]

"Most of the experiments were carried out in a 20’ x 24’ x 9’ virtual test room."
perhaps some in the thread have empty virtual rooms.

If your intent is to reference the Welti paper, the formulas are given such that you can use whatever dimensions you wish.

 

[scanspeak]

I built my own subwoofers so can offer some practical advice.
I used 2 subwoofers, each consisting of a 10" driver in a 40 litre sealed box.The driver is the Seas L26ROY04Y.

http://www.seas.no/index.php?option...4-l26ro4y&catid=97:extreme-woofers&Itemid=600

2 x 10" drivers have the same surface area as 1 x 15" woofer. Being placed close to my seating position means they require less power.

They are driven by a single stereo Rotel ICE amplifier (200W) and their narrow tall enclosures also serve as a stands for my rear surround speakers.
Good WAF, versatile placement, plenty of output.

 

[watchnerd]

I built my own subwoofers so can offer some practical advice.
I used 2 subwoofers, each consisting of a 10" driver in a 40 litre sealed box.The driver is the Seas L26ROY04Y.

http://www.seas.no/index.php?option...4-l26ro4y&catid=97:extreme-woofers&Itemid=600

2 x 10" drivers have the same surface area as 1 x 15" woofer. Being placed close to my seating position means they require less power.

They are driven by a single stereo Rotel ICE amplifier (200W) and their narrow tall enclosures also serve as a stands for my rear surround speakers.
Good WAF, versatile placement, plenty of output.

Those are nice drivers.

How much do they cost?

 

[scanspeak]

US$280.
https://www.madisoundspeakerstore.com/approx-10-subwoofers/seas-l26roy-10-subwoofer-d1001-04-4-ohm/

Test review here
https://audioxpress.com/article/test-bench-the-l26roy-10-subwoofer-from-seas

Someone elses project here
https://www.stereo.net.au/forums/topic/253708-seas-10-semi-diy-sealed-sub-project/

Build your own subwoofer(s) and you'll have premium parts compared to most retail subs, and save a fortune.

 

[georgeT]

If your intent is to reference the Welti paper, the formulas are given such that you can use whatever dimensions you wish.

My intent is to point out that those papers on multiple subs are for viewing/listening rooms without furniture not for regular rooms. It makes more sense to position furniture and treat the room such that one subwoofer produces all the low end you need.
REL recommends placing subwoofers in corners, one of the worst places to put a sub, but with one caveat, to cross them over at 20-30hz to avoid room modes in the 40-80 hz range which are the nastiest.

 

[Jukka]

In short: there is no such thing as too big subwoofer for given room. Once you kill room modes, every other problem is bested with volume knob.

Larger diameter allows better low extension and generally all 12" needs eq to reach 20 Hz flat in any place. My recommendation: big woofer in a closed box is best. If you cannot afford two, get one good and another later.

When in Europe, check out https://arendalsound.eu/ They got high performance yet excellent value subs.

 

[Senior NEET Engineer]

Go with the best single sub you are willing to buy, and add more later if needed. Multisub for room modes doesn't have much benefit unless you want to seat 5+ other audiophiles in a theater and have heavy bass trapping in the room.

 

[Koeitje]

In short: there is no such thing as too big subwoofer for given room. Once you kill room modes, every other problem is bested with volume knob.

Larger diameter allows better low extension and generally all 12" needs eq to reach 20 Hz flat in any place. My recommendation: big woofer in a closed box is best. If you cannot afford two, get one good and another later.

When in Europe, check out https://arendalsound.eu/ They got high performance yet excellent value subs.

In terms of budget I am looking at 2 SB1000's right now. Also easy to pick those up second hand (I don't buy new if I can buy second hand).

 

[Peas]

If you aim for budget, you really should consider DIY with multiple subs. Finished subs are okay as long as you just need one. But especially sealed subs have their own pre-EQ which you will override depending on exact positioning. So you don't need electronics within each sub as this can be done better by a central controller (a DSP).

For 20 Hz, you will need SPL, otherwise you won't hear it because the ear is not that sensitive for low bass at low volumes. Hence, systems like Audyssey add on up to 20 dB at 20 Hz to compensate for this.

That's why a typical setup aiming at 40 Hz isn't remotely as challenging. Most floorstanders can handle that although a DSP is recommended.

But when it comes to 20 Hz, things are different in every regard (room acoustics, cone area, amping ...).

I don't think you'll be satisfied with two 10" drivers in CB. I would recommend at least two 12" woofers.

Following your name, I assume that you come from the Netherlands, so have a look at these drivers:
https://www.soundimports.eu/de/dayt...MIldKn2srO6QIVx_hRCh1FoAeOEAAYASAAEgIlSPD_BwE

Otherwise, if you head for cheaper drivers, it will be easier to add on more later on if neccessary.

 

[Koeitje]

If you aim for budget, you really should consider DIY with multiple subs. Finished subs are okay as long as you just need one. But especially sealed subs have their own pre-EQ which you will override depending on exact positioning. So you don't need electronics within each sub as this can be done better by a central controller (a DSP).

For 20 Hz, you will need SPL, otherwise you won't hear it because the ear is not that sensitive for low bass at low volumes. Hence, systems like Audyssey add on up to 20 dB at 20 Hz to compensate for this.

That's why a typical setup aiming at 40 Hz isn't remotely as challenging. Most floorstanders can handle that although a DSP is recommended.

But when it comes to 20 Hz, things are different in every regard (room acoustics, cone area, amping ...).

I don't think you'll be satisfied with two 10" drivers in CB. I would recommend at least two 12" woofers.

Following your name, I assume that you come from the Netherlands, so have a look at these drivers:
https://www.soundimports.eu/de/dayt...MIldKn2srO6QIVx_hRCh1FoAeOEAAYASAAEgIlSPD_BwE

Otherwise, if you head for cheaper drivers, it will be easier to add on more later on if neccessary.

I don't have the room nor tools to build my own, and SB1000's have 12" woofers.

 

[Bjorn]

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.

Part of this is incorrect.

First of all: There's no rule that placing a subwoofer in the corner is necesarry bad in regards to trigger room modes, ringing and resonances. Quite the opposite: It's often something that works very well for monopoles with the combination of very flat response with added gain. But it depends and will vary.

Below is a response from a subwoofer placed in the corner of a room without any EQ:



Secondly. He says that using multiple subwoofers only evens out the response with 1-2 dB. You can't make a generalization like that. There are several ways to set up several subwoofers and it can even out the response a lot more than that.

But I would say is that the weaknesses with multiple subwoofer approcah are the following:
- It doesn't always sound well integrated but a bit messy. This will depend on several factors like placement and whether it's signal aligned
- It doesn't always make the time domain better (if it's non minimum phase behaviour)
- It doesn't do anything for the frequency area above approximately 80-100 Hz and this area is often more important than subfrequencies.

Bottom line is that you really need broadband bass treatment for an optimal result but use of several subwoofers can certainly help and work quite well.

 

[watchnerd]

My intent is to point out that those papers on multiple subs are for viewing/listening rooms without furniture not for regular rooms. It makes more sense to position furniture and treat the room such that one subwoofer produces all the low end you need.
REL recommends placing subwoofers in corners, one of the worst places to put a sub, but with one caveat, to cross them over at 20-30hz to avoid room modes in the 40-80 hz range which are the nastiest.

Please provide data to support the impact of furniture on room nodes.

Otherwise, you have a hypothesis with no proof.

You might be right, wrong, or half right. Without data, though, it's just an assertion or guess.

 

[gattaca]

^^^ Bjorn nailed it. +++ Yeap furniture / surfaces absorb and reflect. There's been debate for the past 20+ years on 1 or 2 or 3 or 4+ subs. We know we can double the output with 2 so it's size vs complexity. I view the answer as summing more smaller motors to handle the size of a job and what that costs to implement in more ways than just $.

The quality depends on which side of the sea-saw you are seeking (musical or theater). After that then the size, shape and construction of your listening space and finally the most important (and likely out-of your control) is the spouse-acceptance-factor or wife-acceptance-factor for "more black monoliths" in her room - as I've learned after so many years.

I've used twin HSU subs for 20+ years. I have been very pleased with the movie delivery in a nearly 9Kft3 "open floor plan". It's very hard to control all those room modes and placement of subs in these spaces vs "rectangular rooms" If you are designing a music room, then you have more control but what I've learned is when the SAF/WAF kicks in, it always wins - no matter which room it is...unless maybe it's your man cave.

When in doubt, give yourself audio headroom by using the larger woofers. The SAF/WAF visual difference in a 10" vs. 12" or larger size may be all you have to work with and those units may be only allowed to sit in certain non-optimal places. Out of walk ways seems to be the most difficult in open floor plans so multiples helps there. Bottom line: headroom - when you do need more lower-end frequencies for that killer movie, you might be able to deliver it. Of course, YMMV. Peace.

 

[watchnerd]

^^^ Yeap furniture absorbs and reflects. .

It does, but it doesn't do so equally at all frequencies.

 

[detlev24]

↑

@Wayne A. Pflughaupt or, if somebody is interested: I added a distortion measurement, which was taken after the calculated MSO tunings had been applied to both the subwoofers.

In terms of budget I am looking at 2 SB1000's right now. Also easy to pick those up second hand (I don't buy new if I can buy second hand).

In terms of budget, you should still not completely discharge BK Electronics. For instance, you could get 12" driven/12" passive radiator sealed subwoofer(s), with an equivalent area to a 17" woofer - or double 10" driven sealed subwoofer(s), with an equivalent area to a 14" woofer. Cabinet vibrations should be lower as well, as the subwoofer(s) simply have more weight. It is a bit hard to find measurements of the new BK subwoofers; but you might want to send a request directly to the manufacturer. // BK subwoofers would probably give you (one of) the best cost/performance ratio(s) in Europe; besides following a DIY approach.

I am not sure if the SB-1000 would allow for an "easy" integration with your M106, since it seems to roll-off quite early, prior to 80 Hz, on its base frequency response [called "Groundplane" on the following measurement, upper graph; where the blue curve shows the minimum, and the green curve the maximum low pass filter settings]. Although, it seems you plan to use the IOTAVX AVX1 processor for subwoofer integration, one of the higher low pass filter settings on the SB-1000 might be more practical; instead of bypass via [LFE]-position selection.


[ Source: SVS Germany ]

Furthermore, if we consider the two green 90 dB curves on the lower graph, we get a distortion of roughly 16% at ~27 Hz; by application of the formula to calculate THD in %: THD = [10^(-ΔdB/20)] x 100. Where in this specific case, Δ would be roughly 89 dB [fundamental] - 73 dB [distortion] = 16 [dB].

 

[Jukka]

In terms of budget I am looking at 2 SB1000's right now. Also easy to pick those up second hand (I don't buy new if I can buy second hand).

Some user reviews of Arendal 1723 Sub 1 say that it's far better than SB2000. I haven't got personal experience of those, but I'm very happy with my Arendal.

+1 for buying used. A used sub is usually about the same value as diy nowadays where I live. Always listen before buying.

 

[Koeitje]

Some user reviews of Arendal 1723 Sub 1 say that it's far better than SB2000. I haven't got personal experience of those, but I'm very happy with my Arendal.

+1 for buying used. A used sub is usually about the same value as diy nowadays where I live. Always listen before buying.

That one is €300 more than the SB1000, which is more in my budget range if I need two. I can easily fit two subs and have several options for placing them.

If somebody is interested: I added a distortion measurement, which was taken after the calculated MSO tunings had been applied to both the subwoofers.


In terms of budget, you should still not completely discharge BK Electronics. For instance, you could get 12" driven/12" passive radiator sealed subwoofer(s), with an equivalent area to a 17" woofer - or double 10" driven sealed subwoofer(s), with an equivalent area to a 14" woofer. Cabinet vibrations should be lower as well, as the subwoofer(s) simply have more weight. It is a bit hard to find measurements of the new BK subwoofers; but you might want to send a request directly to the manufacturer. // BK subwoofers would probably give you (one of) the best cost/performance ratio(s) in Europe; besides following a DIY approach.

I am not sure if the SB-1000 would allow for an "easy" integration with your M106, since it seems to roll-off quite early, prior to 80 Hz, on its base frequency response [called "Groundplane" on the following measurement, upper graph; where the blue curve shows the minimum, and the green curve the maximum low pass filter settings]. Although, it seems you plan to use the IOTAVX AVX1 processor for subwoofer integration, one of the higher low pass filter settings on the SB-1000 might be more practical; instead of bypass via [LFE]-position selection.

View attachment 65358
[ Source: SVS Germany ]

Furthermore, if we consider the two green 90 dB curves on the lower graph, we get a distortion of roughly 16% at ~27 Hz; by application of the formula to calculate THD in %: THD = [10^(-ΔdB/20)] x 100. Where in this specific case, Δ would be roughly 89 dB [fundamental] - 73 dB [distortion] = 16 [dB].

The BK Double Gem also looks pretty nice, but its hard to find proper reviews. I'm also looking at XTZ, they also seem to be pretty good.

 

[georgeT]

Please provide data to support the impact of furniture on room nodes.

Otherwise, you have a hypothesis with no proof.

You might be right, wrong, or half right. Without data, though, it's just an assertion or guess.

You mean to tell me a 6 foot dresser (for example) doesn't influence room modes??? It basically changes the room shape and I'm pretty sure there's been studies on room shape and room modes.

 

[watchnerd]

You mean to tell me a 6 foot dresser (for example) doesn't influence room modes??? It basically changes the room shape and I'm pretty sure there's been studies on room shape and room modes.

I didn't say that it doesn't have an effect.

I said please share the data that shows how much the effect is and at which frequencies.

Your dresser may resonate at frequencies above the fundamental frequency of the room, and thus above the standing wave room nodes.

I would expect a dresser to act a bit like a Helmholz resonator, with a Q depending on how empty it is.

 

[Bjorn]

In regards to two 10" vs one 12" subwoofer.
As long as the 10" subs holds high quality, two of those will general give you higher output and lower distortion compared to one 12". Obviously this can change if the quality differs.

King of subwoofer is horn by the way. But a true horn loaded subwoofer takes a lot of space.