Who Can Answer My Six Easy / Tricky Subwoofer Questions?

Hear Here

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Feb 14, 2020
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Portsmouth, UK
OK, here the situation. I have never owned a stand-alone sub, as all my speakers have offered very good and deep bass without the need for them. With the exception of my ATC50 Actives (with a single 9” bass driver), all my speakers in the last 30+ years have had twin 10” or twin 12” bass drivers. Earlier ones (from the 1960s) had single 15” drivers.

So here are my questions, prompted by claims that adding subs will significantly improve the quality of bass by filling in or neutralising anomalies in the sound that reaches my ears, as a result of room features. Incidentally the room – see rough plan attached – has already been worked on to achieve a good sound with partial carpeting, curtains, soft furnishings, etc as well as very careful speaker setting up.

1. Do my Avantgarde Duo XD speakers with their twin 12” drivers, need subs at all to improve sound quality or to smooth the bass response? I suspect many will say Yes.

2. If so, do I need these subs to have 12” or larger drivers? I’m hoping that smaller subs, perhaps with 10” drivers will do the job just as well, as I don’t need deeper bass, just smoother

3. How many subs should I be looking to add? I’m told that at least 2 is the likely answer, but my new preamp (if I get the NAD M66) has outputs for up to 4 subs, all of which can be DSP’d by Dirac Live and / or Dirac Live Bass Control.

4. I don’t want signal cables trailing across the floor to these subs. Can I run subs equally well wirelessly? If so what (preferably XLR – XLR) transmitter / receiver devices would do the job. I’m not concerned about power cables as power can be found locally. Or I could use subs that already have a wireless feature, but of course I don’t want to compromise on quality.

5. The big question – which subs should I go for and how many? Good quality without having daft prices.

6. The equally big question - where should I place them? Main options, marked in green on the plan with a number or a letter, are where subs could be placed. Subs in positions B, 3 and 4 could be hard-wired to the preamp using XLR interconnects.

Your expert knowledge of all things sub and your imagination would be greatly appreciated.

A challenge I hope you may enjoy! :) Thanks. Peter
 

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subs need to be powered off of speaker terminals
now this is not an absolute but here is a reason why
amps play to your speakers and have there own sound due to loads
so if you use a preamp out you have now placed an Additional load on your preamp this effects how the speaker sound
if you use speaker term out your getting exactly what is going to your speakers
so it’s more accurate. if you use wireless I can’t say this is bad as long as high outputs are used
next why and how to blend them so all is not cut into pcs.
have you measured your room to see not only hear
What is taking place there.
maybe I’m asking too many questions lol
 
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subs need to be powered off of speaker terminals
now this is not an absolute but here is a reason why
amps play to your speakers and have there own sound due to loads
so if you use a preamp out you have now placed an Additional load on your preamp this effects how the speaker sound
if you use speaker term out your getting exactly what is going to your speakers
so it’s more accurate. if you use wireless I can’t say this is bad as long as high outputs are used
next why and how to blend them so all is not cut into pcs.
have you measured your room to see not only hear
What is taking place there.
maybe I’m asking too many questions lol
Thanks for replying.

M66 - Front and Back Panels.pngIf I go for the M66 preamp, it offers multiple sub outputs at line level - see photo. It also include DL and DLBC to ensure that each sub is adjusted to work in harmony with the main speakers and the main speaker's signal is totally unaffected by any sub attached via the preamp's sub outs. There's no way my 100 watt power amp would like to have multiple subs attached to its terminals! So I have no concerns about most of your points as the preamp and its built-in DSP is designed to cater for these multiple subs.

I have measured the room but not recently. My Dirac filters (that I preferred not to engage) in my present NAD M33 were lost when I had to do a factory reset. I'll do more readings soon using REW and a calibrated UMIK-1 microphone. However, this will be done primarily to make DSP adjustments within my speakers' sub amps, using Avantgarde's own XD software. I could also use Dirac's software to create an "auto-adjust" filter within the M33. However I am unlikely to find this Dirac filter beneficial. In the past, I've always preferred the sound without the Dirac filter.
 
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I’m sorry for not giving a better reply
when i said to use the amp output terminals for subs
I only mean for signal input to subs and assuming they have both line and speaker level inputs and are self powered.
now having said this that’s a nice receiver
and yes dedicated subs line level is a cool feature
does this receiver have settings to limit the low freq to main speakers ?
this feature is useful as it allows for a true cross over point so you don’t have 2 different drivers at same freq
your room is very large and looks nice
how high is the ceilings ?
location on your plan seems ok but can you place subs on both sides of the tv / main speakers
not on sides touching but on either side
to better balance the sound of subs in the room
 
Hello

No expert but what has worked for me.

Size depends on how low and how loud. SD is the king as the more air you can move the more a sense of ease.

How low do your mains actually go? What 40Hz? If you want -6 and @20 or -6@ 16?

I am -6@ 20Hz and I find it plenty WRT pants flapping.

I have 4 15"s in my HT 2 LFE and a L/R. My living room I use a single 14 so I would start with a pair and see how well things go.

My placement has always been very close to the main speaker plain. I have been lucky with placement and they integrated best there.

Looks like you have excellent bass management so you should have an easier time getting it all to work providing you take the time to really learn the software available to you.

Looks like a nice room!

Have fun!

Rob :)
 
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Hello

No expert but what has worked for me.

Size depends on how low and how loud. SD is the king as the more air you can move the more a sense of ease.

How low do your mains actually go? What 40Hz? If you want -6 and @20 or -6@ 16?

I am -6@ 20Hz and I find it plenty WRT pants flapping.

I have 4 15"s in my HT 2 LFE and a L/R. My living room I use a single 14 so I would start with a pair and see how well things go.

My placement has always been very close to the main speaker plain. I have been lucky with placement and they integrated best there.

Looks like you have excellent bass management so you should have an easier time getting it all to work providing you take the time to really learn the software available to you.

Looks like a nice room!

Have fun!

Rob :)
Thanks Rob and Alrainbow for your helpful replies.

Sorry, but I'm totally confused by the many abbreviations you use. For example, what is a "HT 2 LFE", or SD, or 14, or even L/R, though I guess this may be Left / Right.

The Duo XD's bass extension from its twin 12" drivers each channel is quoted as 18 or 22 Hz depending on where you look. However, as I said, I'm not interested in more bass or deeper bass. The suggestion is that adding subs may improve the quality of the bass.

The M66 has outputs for up to 4 subs and the active XO within the M66 can be adjusted between 80m - 200 Hz, although I imagine this could also be set using the sub's own settings. The preamp's Dirac Live and / or Dirac Live Bass Control should avoid any "2 different drivers at same freq" problem you mention.

I could place subs close to the main speakers - easier on the left speaker as there's a display cabinet to the right, that could be moved if necessary.

Sadly the ceiling height is a rather low 7 ft 7".

Room photo here


20210708_185716.jpg
 
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Nice 4X5, must be special.
 
Thanks Rob and Alrainbow for your helpful replies.

Sorry, but I'm totally confused by the many abbreviations you use. For example, what is a "HT 2 LFE", or SD, or 14, or even L/R, though I guess this may be Left / Right.

The Duo XD's bass extension from its twin 12" drivers each channel is quoted as 18 or 22 Hz depending on where you look. However, as I said, I'm not interested in more bass or deeper bass. The suggestion is that adding subs may improve the quality of the bass.

The M66 has outputs for up to 4 subs and the active XO within the M66 can be adjusted between 80m - 200 Hz, although I imagine this could also be set using the sub's own settings. The preamp's Dirac Live and / or Dirac Live Bass Control should avoid any "2 different drivers at same freq" problem you mention.

I could place subs close to the main speakers - easier on the left speaker as there's a display cabinet to the right, that could be moved if necessary.

Sadly the ceiling height is a rather low 7 ft 7".

Room photo here


View attachment 131430

Sorry for the confusion

I have 4 15 inch woofers in my Home Theater used as subs 2 Low Frequency Effects and a Left/Right. All crossed at 80 hz. I also use Left and Right 15" mid-woofers so I have a lot of surface area covering 300Hz and down.

On a personal note larger woofers with more area, SD, sound better to me moving a fraction of an inch vs 8's going through 1 inch strokes to move the same air. That's a preference thing to me less excursion = effortless not strained.

My living room I use a single 14 inch subwoofer crossed over to a pair of Revel F 206's @80Hz. Takes the heavy lifting off the pair of 6" woofers. Small room more than enough with the single.

Why do you think adding subs will help in the bass?

It's large space do you get good pressurization and can you feel it?

Does it have the extension but not enough weight?

Does the low bass compress assuming it has built in amps for the 12's?

If you are not output shy and don't have issues with room modes can you borrow a sub from a dealer or friend and experiment?

Before you pull the trigger I would see it adding sub's works for you and gets the improvement you are seeking.

Rob :)
 
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Generally I would put subwoofers on a ham sandwich.

Even if there is some overlap with the full range speakers which results in a touch of muddiness (ideally there would not be any muddiness or any other sonic negative) it is outweighed, for me, by increased corporeal-ness and impact and sound-stage ambiance and weight to the overall sonic foundation.

I think a pair of REL 212/SX is easy to connect, is not tragically expensive and would teach you a lot about whether or not you like the whole subwoofer concept.
 
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Here's a breakdown of your questions about improving the bass response of your Avantgarde Duo XD speakers:
  1. Subwoofers for Smoother Bass:
  • Your speakers with dual 12" drivers can benefit from subwoofers for smoother bass response. Room acoustics and placement can significantly impact bass. Subs can help fill in low-frequency dips and achieve a more even response.
  • Not everyone agrees adding subs is necessary. You might want to try optimizing speaker placement and room acoustics first.
  1. Subwoofer Driver Size:
  • You don't necessarily need 12" drivers in the subs. Smaller 10" drivers can work well for smoothing bass, especially if you're not aiming for ultra-deep bass extension.
  1. Number of Subwoofers:
  • Two subwoofers are ideal for smoother, more even bass distribution across the listening area. This helps counteract room modes that cause uneven bass response.
  • With Dirac Live in your NAD M66 preamp, you can potentially utilize up to 4 subs and achieve excellent bass control. However, 2 well-placed subs with Dirac Live can be very effective.
  1. Wireless Subwoofers:
  • Wireless subwoofers offer convenience, but wired connections (XLR or RCA) are generally preferred for better sound quality due to potential latency and compression issues with wireless.
  • If you choose wireless, prioritize high-quality systems with minimal latency and good reviews. Look for brands with established reputations in subwoofers.
  1. Subwoofer Recommendations:
  • It's difficult to recommend specific models without knowing your budget. However, focus on reputable subwoofer brands known for good sound quality and room correction capabilities. Look for models with built-in DSP or compatibility with Dirac Live. If you want to keep budget on control, would start checking Perlisten subwoofers
  • Online resources like AudioScienceReview subwoofer reviews can be helpful for comparing subwoofer performance.
  1. Subwoofer Placement:
  • Experiment with different placements to find the optimal locations. Ideally, avoid corners,which can lead to boomy bass.
  • Use Dirac Live room correction software to measure and calibrate your subwoofers for the best performance in your listening space.
Additional Tips:
  • Start with two well-placed subwoofers and Dirac Live calibration before adding more.
  • Consider in-wall subwoofers if aesthetics are a concern and placement allows.
  • Consult a professional audio installer for assistance with subwoofer selection, placement, and calibration.
By adding subwoofers you can improve the bass response of your Avantgarde Duo XD speakers and achieve a more satisfying listening experience.
 
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Thanks Rob and Alrainbow for your helpful replies.

Sorry, but I'm totally confused by the many abbreviations you use. For example, what is a "HT 2 LFE", or SD, or 14, or even L/R, though I guess this may be Left / Right.

The Duo XD's bass extension from its twin 12" drivers each channel is quoted as 18 or 22 Hz depending on where you look. However, as I said, I'm not interested in more bass or deeper bass. The suggestion is that adding subs may improve the quality of the bass.

The M66 has outputs for up to 4 subs and the active XO within the M66 can be adjusted between 80m - 200 Hz, although I imagine this could also be set using the sub's own settings. The preamp's Dirac Live and / or Dirac Live Bass Control should avoid any "2 different drivers at same freq" problem you mention.

I could place subs close to the main speakers - easier on the left speaker as there's a display cabinet to the right, that could be moved if necessary.

Sadly the ceiling height is a rather low 7 ft 7".

Room photo here


View attachment 131430
Beautiful room! RELs generally have well-regarded wireless solutions. On the outer edge of the main speakers seems a logical place to start, one on each side. Given the likely dispersion and room-filling capability of your AG horns, I would not be at all afraid to go for some of their bigger flagships or their stacked solutions with smaller subs...real dispersion capability done right in my experience means lower distortion at the same level. Plus, the latter option of stacked subs (with some setup work) might prove to be better in-room in terms of adjustability as each sub in the stack (2 or 3 per side) are then independently adjusted.
 
Sorry for the confusion

I have 4 15 inch woofers in my Home Theater used as subs 2 Low Frequency Effects and a Left/Right. All crossed at 80 hz. I also use Left and Right 15" mid-woofers so I have a lot of surface area covering 300Hz and down.

On a personal note larger woofers with more area, SD, sound better to me moving a fraction of an inch vs 8's going through 1 inch strokes to move the same air. That's a preference thing to me less excursion = effortless not strained.

My living room I use a single 14 inch subwoofer crossed over to a pair of Revel F 206's @80Hz. Takes the heavy lifting off the pair of 6" woofers. Small room more than enough with the single.

Why do you think adding subs will help in the bass?

It's large space do you get good pressurization and can you feel it?

Does it have the extension but not enough weight?

Does the low bass compress assuming it has built in amps for the 12's?

If you are not output shy and don't have issues with room modes can you borrow a sub from a dealer or friend and experiment?

Before you pull the trigger I would see it adding sub's works for you and gets the improvement you are seeking.

Rob :)
Generally I would put subwoofers on a ham sandwich.

Even if there is some overlap with the full range speakers which results in a touch of muddiness it is outweighed, for me, by increased corporeal-ness and impact and sound-stage ambiance and weight to the overall sonic foundation.

I think a pair of REL 212/SX is easy to connect, is not tragically expensive and would teach you a lot about whether or not you like the whole subwoofer concept.
Thanks Rob and Ron - all helpful stuff.

I think Ron has described the sort of improvement I am hoping for and what others have suggested both here and on other forums. No extra bass volume and likely no deeper bass is needed, but hopefully the benefits he suggests resulting in better bass and overall improved sound..

Rob - I hope the above paragraph addresses some of your points, but I'm not into Home Theatre, hence my search only for "better bass" not so much for more of it.

Regarding your next 3 questions, I'm really very happy with my simple system of just 2 full-range high quality speakers with their hybrid (1000 watt) active twin 12" bass drivers. However I feel, prompted by many here and elsewhere, that adding subs should sort out any remaining room-influenced nodes, etc. With the purchase of the M66 with its built-in DL and DLBC and 4 Sub Outs, now is perhaps the time for me to consider this previously alien concept!

From what you and others have suggested, I should perhaps start by arranging a loan of 2 subs. The dealer I'm likely to get my M66 from has a huge range on his website, though perhaps not many available for loan. I would like to think that subs with 10" drivers may satisfactorily deal with nodes, etc, as the thought of those huge RELs fills me with dread! I really wouldn't relish the sight of those monsters in my living room - but perhaps worth trying if my dealer has them. Thanks again. Peter
 
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Rob - I hope the above paragraph addresses some of your points, but I'm not into Home Theatre, hence my search only for "better bass" not so much for more of it.

Hello Peter

My HT and main stereo are the same system. When I run stereo I only use Left and Right subs. They are there to complete the bass as my 15 inch mid bass drivers are high sensitivity @ 98dB 1 watt and don't have the last octave and a half. They give up the ghost at about 60Hz. The subs are the foundation for the speakers and the bass isn't right without them.

That said I understand more is not what you are looking for. That's why I asked about room modes as an example as multiple subs can be beneficial if indeed that is where the problem lies.

Let is know how it goes!

Rob :)
 
Here's a breakdown of your questions about improving the bass response of your Avantgarde Duo XD speakers:
  1. Subwoofers for Smoother Bass:
  • Your speakers with dual 12" drivers can benefit from subwoofers for smoother bass response. Room acoustics and placement can significantly impact bass. Subs can help fill in low-frequency dips and achieve a more even response.
  • Not everyone agrees adding subs is necessary. You might want to try optimizing speaker placement and room acoustics first.
  1. Subwoofer Driver Size:
  • You don't necessarily need 12" drivers in the subs. Smaller 10" drivers can work well for smoothing bass, especially if you're not aiming for ultra-deep bass extension.
  1. Number of Subwoofers:
  • Two subwoofers are ideal for smoother, more even bass distribution across the listening area. This helps counteract room modes that cause uneven bass response.
  • With Dirac Live in your NAD M66 preamp, you can potentially utilize up to 4 subs and achieve excellent bass control. However, 2 well-placed subs with Dirac Live can be very effective.
  1. Wireless Subwoofers:
  • Wireless subwoofers offer convenience, but wired connections (XLR or RCA) are generally preferred for better sound quality due to potential latency and compression issues with wireless.
  • If you choose wireless, prioritize high-quality systems with minimal latency and good reviews. Look for brands with established reputations in subwoofers.
  1. Subwoofer Recommendations:
  • It's difficult to recommend specific models without knowing your budget. However, focus on reputable subwoofer brands known for good sound quality and room correction capabilities. Look for models with built-in DSP or compatibility with Dirac Live. If you want to keep budget on control, would start checking Perlisten subwoofers
  • Online resources like AudioScienceReview subwoofer reviews can be helpful for comparing subwoofer performance.
  1. Subwoofer Placement:
  • Experiment with different placements to find the optimal locations. Ideally, avoid corners,which can lead to boomy bass.
  • Use Dirac Live room correction software to measure and calibrate your subwoofers for the best performance in your listening space.
Additional Tips:
  • Start with two well-placed subwoofers and Dirac Live calibration before adding more.
  • Consider in-wall subwoofers if aesthetics are a concern and placement allows.
  • Consult a professional audio installer for assistance with subwoofer selection, placement, and calibration.
By adding subwoofers you can improve the bass response of your Avantgarde Duo XD speakers and achieve a more satisfying listening experience.
Many thanks - This is just the sort of advice I was looking for as I'm still a sub-virgin! Up till recently I've dismissed most of the sub "advice" I've been offered, but as my #12 post above suggests, I'm now giving the idea serious consideration.

I will carefully study your advice and suggestions and will talk with my dealer with these in mind. As a matter of interest / curiosity, I notice from your profile an absence of subs in your own system! Is this because you have them but haven't listed them, or you find you don't need them with your Magico speakers?

I've worked hard to get my Avantgardes as well set up as I possibly can and added features such as partial carpeting to reduce room problems without resorting to nasty-looking room treatment. I'm confident they are sounding their best given the level of electronics I'm using to feed them. The plan is to replace the NAD M33 with M66 plus a pair of Atma-Sphere Class D monos.

Beautiful room! RELs generally have well-regarded wireless solutions. On the outer edge of the main speakers seems a logical place to start, one on each side. Given the likely dispersion and room-filling capability of your AG horns, I would not be at all afraid to go for some of their bigger flagships or their stacked solutions with smaller subs...real dispersion capability done right in my experience means lower distortion at the same level. Plus, the latter option of stacked subs (with some setup work) might prove to be better in-room in terms of adjustability as each sub in the stack (2 or 3 per side) are then independently adjusted.

Many thanks - Please read the above reply as addressed to you too. Very helpful and encouraging to see some degree of consensus.
 
Just a thought?

Have you evaluated your set-up using a test disk? All you need is to try a LF sweep and you are going to hear immediately if you have modes and where they are.

Rob :)
 
Just a thought?

Have you evaluated your set-up using a test disk? All you need is to try a LF sweep and you are going to hear immediately if you have modes and where they are.

Rob :)
Some while ago I ran a series of Dirac and REW sweeps and saw the results on my PC. I have ancient Hi-Fi News and Stereophile test CDs - perhaps I'll dig these out. Fresh Dirac and REW sweeps are on the cards as my Dirac filters were lost after a factory reboot of my amp - though I always preferred the sound without these filters.
 
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Some while ago I ran a series of Dirac and REW sweeps and saw the results on my PC. I have ancient Hi-Fi News and Stereophile test CDs - perhaps I'll dig these out. Fresh Dirac and REW sweeps are on the cards as my Dirac filters were lost after a factory reboot of my amp - though I always preferred the sound without these filters.
Hmm me too I had Dirac older version and staid analogy EQ 31 band and 1/8 octave on the subs. The Dirac just killed the sense of space. Of course no EQ is best but really hard to achieve!
Rob :)
 
First of all, large and interesting room. It is likely not without acoustical challenges both in the bass and the rest of the frequency range. In your replies to others you have claimed you are very happy with the sound. When looking for a solution, it's always a good idea to start with a problem. :) That being said, sometimes we don't know what we're missing.

If possible, I think you would benefit greatly from being able to do some measurements of your setup from the listening position. This will help you both see what issues you currently have, and also better track any improvements made when/if introducing subwoofers.

You've got some good replies so far, I will still reply with my perspective as well, hope it is helpful.

1) Will your speakers benefit from subwoofers? Yes, that is an almost certainty unless you are extremely lucky with the room and setup. The primary gain will likely be more even frequency response in the range where the subwoofers assist. This means you should not go the "REL-route" where the subwoofers only help out at the very bottom, but rather have subwoofers play up to 80-100hz, and use a high pass filter so that the speakers does not play these frequencies. The NAD M66 will support this.


2) Do I need subwoofers with 12" or larger drivers? Not necessarily, and it's not about driver size, but total driver surface area. So multiple smaller drivers may work too. Your space is pretty large, so if you are looking to use compact subwoofers, you may need several.


3) How many subs? Yes, at least two.


4) Wireless connection? You can. In a "traditional" system, wireless will introduce some delay / latency which may introduce issues. But the M66 will be able to delay the different channels accordingly, so that the introduced latency of the wireless transmitters won't be a problem.


5) Which subwoofers? I am a subwoofer manufacturer, so I am not able to give an objective answer to this. :)


6) Where? They should not necessarily be placed at the same position as the speakers. Asymmetric position can be beneficial. Position B/3/4 will likely not fully smooth out your bass response, at least not alone. So you could put two in position 3 and 4, and consider also adding two in the positions A and C.
 
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Many thanks - This is just the sort of advice I was looking for as I'm still a sub-virgin! Up till recently I've dismissed most of the sub "advice" I've been offered, but as my #12 post above suggests, I'm now giving the idea serious consideration.

I will carefully study your advice and suggestions and will talk with my dealer with these in mind. As a matter of interest / curiosity, I notice from your profile an absence of subs in your own system! Is this because you have them but haven't listed them, or you find you don't need them with your Magico speakers?

I've worked hard to get my Avantgardes as well set up as I possibly can and added features such as partial carpeting to reduce room problems without resorting to nasty-looking room treatment. I'm confident they are sounding their best given the level of electronics I'm using to feed them. The plan is to replace the NAD M33 with M66 plus a pair of Atma-Sphere Class D monos.



Many thanks - Please read the above reply as addressed to you too. Very helpful and encouraging to see some degree of consensus.
There are a couple of reasons I don't currently work with a subwoofer, although several of my friends do, including one with an AG Trion and four Basshorns.

1. Space: The main reason is space. The typical living room size in the average apartment here is limited. With so many components already in place, fitting in a subwoofer or two where my setup is located is almost impossible.

2. Logistics: Subwoofers require electricity and cables, necessitating an upgrade to my electrical system and outlets, which are already stressed.

3. Recent Upgrade: I just ordered an S5 to replace my S3. While the S5 can't address all the acoustic issues that a subwoofer can, it is more than sufficient for handling the lower octaves.
 

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