Single or Dual SVS Subs

[Brash]

I'm looking to add sub's to an existing 2-channel hi-fi system in my living room.  The current system consists of a pair of Kef Q700's powered by a Schiit Vidar amp and fed by a Marantz streamer/pre-amp. At some stage I would be upgrading the Q700's to something like the Kef R3's. 

 

My room is 6m wide and 4m deep, and opens on one side to a kitchen. Ceiling is only 2.4m, so the main listening area is 24m², or 57m3. My listening taste is very broad. I wouldn't consider myself a bass-head, rather prefer my EQ to be on the flatter side.  I would consider myself to be a critical listener of good quality recording from any genre. 

 

I am considering either a single SVS SB-2000 Pro, or dual SVS SB-1000 Pros.  Everything I have read would indicate that the dual sub option is a better choice as it will avoid room nodes occurring, but does anyone have any experience with these models to advise whether either option will have any other pro's and con's? I don't tend to listen to music much above 70db, so my goal is to achieve low, tight base at moderate volumes without room nodes, which is why I'm leaning toward the dual setup.

[peterpan]

i use 2 subs atm , large room listen at 85db and above ,but a while back I used one Svs sb 2000 and it was really good. you could always get a second 2000 later if you feel you need it? 

carefully paced one sub especially at your listening volumes should be more than sufficient, imho. 

[Steff]

Here's some food for thought, or homework, depending on the way you look at it:

 

[Brash]

27 minutes ago, peterpan said:

i use 2 subs atm , large room listen at 85db and above ,but a while back I used one Svs sb 2000 and it was really good. you could always get a second 2000 later if you feel you need it? 

carefully paced one sub especially at your listening volumes should be more than sufficient, imho. 

You make a fair point, however the arrangement of all the gear in the space means the 2x 1000's could sit under a wall mounted TV cabinet between the mains, where as anything larger would need to sit outside the mains, and 2 of these would break the WAF requirements 

[Keith_W]

Dual subs are usually better. But what is equally important but often overlooked is a plan to integrate your subs into your system. 

 

This is the FR of the KEF R3. I can't find the FR of the KEF Q700 through a quick search, but i'll comment on this to give you some idea. 

 

 

The KEF R3's roll off bass steeply at 40Hz, but the bass actually starts deviating from target at 120Hz or so. That is very high. Your options to fix this would include: 

 

- run subwoofers up to 120Hz. This will make your subs easily localisable and really limits you to placing them on either side of the speaker. 

- run subwoofers with a steep XO slope to 50-80Hz and cut the volume of the KEF's to match. However you will lose volume and headroom by doing this. 

- run subwoofers with a gentle XO slope (e.g. Linkwitz 2nd order) up to 50-80Hz. You then run the risk of phase cancellation between main speakers and sub due to the substantial overlap between frequencies at the XO region. In fact you always have the risk of phase cancellation between mains and subs, but the risk is greater if you have more substantial overlap. 

- use EQ to boost the KEF's <120Hz. Not recommended, you will definitely run into distortion. 

 

I would also consider stuffing the port of the R3. The port is there to extend the bass frequencies which you no longer need since you have subwoofers. The port also introduces an out-of-phase rear wave that makes bass behaviour more unpredictable since you now have 2 front waves (from the speaker), 2 omnidirectional waves (from the subwoofers), and 2 out-of-phase and uncontrollable rear waves from the port. 

 

So with all that said, will the SVS SB-1000 Pro be able to fill in the missing frequencies? 

 

 

Source. The answer seems to be yes. I don't like how it rolls off <30Hz but that is a characteristic of many small subwoofers and you may get some room gain that fills in the lower frequencies. This is where smaller rooms are sometimes advantageous though I would generally recommend bigger rooms + bigger subs. I doubt if you would get much room gain since your listening room opens to a kitchen but there is no way to tell until you get those subs in your room. Bass that your sub does not create can sometimes be "created" through subwoofer placement but playing this game is somewhat dicey and you will only know after you have spent your money. Having two subs definitely helps. 

 

You will need some kind of bass management strategy. Have a look at my post that @Steff linked to and think about what you are going to do. Good luck! 

EDIT posted wrong graph for the R3 Meta! Oops!! Here is the correct graph. Fortunately the same comments apply. 

 

Edited May 15, 2024 by Keith_W

[Brash]

Thank you so much, this is very informative. I’ll also see if I can find a graph for the Q700’s or there updated Q750’s. With the addition of the bass radiators on each woofer and larger enclosed volume I would expect them to extend a bit lower than the R3’s. 

[Brash]

Here we go, the plot is from this review. Looks to roll off at 100hz at about 3db/oct. 
https://www.stereophile.com/content/kef-r700-loudspeaker-measurements

[Satanica]

2 hours ago, Brash said:

You make a fair point, however the arrangement of all the gear in the space means the 2x 1000's could sit under a wall mounted TV cabinet between the mains, where as anything larger would need to sit outside the mains, and 2 of these would break the WAF requirements 

 

You mind find placing subs on a wall mounted TV cabinet, to cause some kind of vibration issue.

Also, the main benefit of dual or more subs is only really realised when they are a significant distance apart from each other and most likely when there is some randomness in position e.g. one is closer to the main listening area than the other(s).

This assumes that the subwoofers are being run in mono.
Place subwoofers too close to each other, and they will act more like one subwoofer, or even much worse they will cancel each other out more than if there was only one.

I wish multi sub or single sub for that matter was simple, but it is not.

The fact that you have an opening of the listening space to one side, seemingly would help with some randomness.
 

Edited May 15, 2024 by Satanica

[Brash]

Ok, so if going 2x subs is not going to be the quick fix I may have thought, I could invest a similar amount into a single sub. 

 

If you had $2,000 and your priority was sound quality, what single sub would you go? A REL HT/1205 MKII perhaps?

[Satanica]

One subwoofer or two, I think Tonewinner deserves some consideration.

https://www.selby.com.au/catalogsearch/result/?q=Tonewinner+subwoofer

[Keith_W]

3 hours ago, Brash said:

Ok, so if going 2x subs is not going to be the quick fix I may have thought, I could invest a similar amount into a single sub. 

 

If you had $2,000 and your priority was sound quality, what single sub would you go? A REL HT/1205 MKII perhaps?

 

I would run far, far away from REL.

 

And please remember that actually placing the subwoofer properly and integrating it actually contributes more to the sound quality than the choice of subwoofer itself. All you want from the sub is that it produces the frequencies you need, at adequate volume with low distortion, and does not suffer from too much ringing. Of course it has to be priced to what you can afford and be aesthetically acceptable. But everything else - tightness, slam, weightiness, absence of peaks and dips - is a function of how well you have actually used the sub. 

 

Most people have the wrong idea about subs. "Slam" is not a subwoofer thing, it's actually a woofer thing. The sub only fills in the bottom part of the "slam" and gives it some weight. "Tightness" is only half a subwoofer thing, it's a function of whether the sub is time aligned and does not ring. 

 

I like to give a little demonstration in my system on the effect of subwoofers. First I play the system with the mains and subs on. Then I turn the subs off. What is most noticeable is the collapse of the soundstage, some of the texture of the music is also gone. The "boom-boom" is still there, because that is midbass and not low bass (in my system the XO point of the sub is 50Hz). Then I turn the mains off and play the subs by themselves. You can barely hear them, they are only barely perceptible as a low rumble. 

 

Getting one sub instead of two is a good idea. You can get a higher quality sub that way and you could always add another sub in the future if you need to. If you have more money to spend, choose a sub with a larger driver. A 10" sub has a surface area of 78 sq in, a 12" sub has a surface area of 113 sq in. Going up one size to 12" gives you almost 50% more surface area and therefore more volume. The reason why you want the capacity for more volume is not so that you can go loud, it is so that you can play the sub at low volume with less distortion. 

[tripitaka]

4 hours ago, Brash said:

Ok, so if going 2x subs is not going to be the quick fix I may have thought, I could invest a similar amount into a single sub. 

 

If you had $2,000 and your priority was sound quality, what single sub would you go? A REL HT/1205 MKII perhaps?

SVS is great bang for buck, suggest going for their Pro range.

[Grizaudio]

On 15/05/2024 at 6:22 PM, Keith_W said:

 

I would run far, far away from REL.

 

And please remember that actually placing the subwoofer properly and integrating it actually contributes more to the sound quality than the choice of subwoofer itself. All you want from the sub is that it produces the frequencies you need, at adequate volume with low distortion, and does not suffer from too much ringing. Of course it has to be priced to what you can afford and be aesthetically acceptable. But everything else - tightness, slam, weightiness, absence of peaks and dips - is a function of how well you have actually used the sub. 

 

Most people have the wrong idea about subs. "Slam" is not a subwoofer thing, it's actually a woofer thing. The sub only fills in the bottom part of the "slam" and gives it some weight. "Tightness" is only half a subwoofer thing, it's a function of whether the sub is time aligned and does not ring. 

 

I like to give a little demonstration in my system on the effect of subwoofers. First I play the system with the mains and subs on. Then I turn the subs off. What is most noticeable is the collapse of the soundstage, some of the texture of the music is also gone. The "boom-boom" is still there, because that is midbass and not low bass (in my system the XO point of the sub is 50Hz). Then I turn the mains off and play the subs by themselves. You can barely hear them, they are only barely perceptible as a low rumble. 

 

Getting one sub instead of two is a good idea. You can get a higher quality sub that way and you could always add another sub in the future if you need to. If you have more money to spend, choose a sub with a larger driver. A 10" sub has a surface area of 78 sq in, a 12" sub has a surface area of 113 sq in. Going up one size to 12" gives you almost 50% more surface area and therefore more volume. The reason why you want the capacity for more volume is not so that you can go loud, it is so that you can play the sub at low volume with less distortion. 

 

A sub is producing a fundamental frequency and a series integer multiple higher frequencies [harmonics], which impact much more than just the bass frequencies. 

 

These frequencies impact timbre [tone quality] and overall quality of sound. 

[playdough]

On 15/05/2024 at 6:22 PM, Keith_W said:

I would run far, far away from REL.

[andyr]

39 minutes ago, Grizaudio said:

These frequencies impact timbre [tone quality] and overall quality of sound. 

 

Very true!

 

However:

 

40 minutes ago, Grizaudio said:

A sub is producing a fundamental frequency and a series integer multiple higher frequencies [harmonics], which impact much more than just the bass frequencies. 

 

... as the sub has a LP filter applied to it ... this limits the frequencies - and harmonics of these frequencies - that it can produce.

 

[playdough]

10 minutes ago, andyr said:

.. as the sub has a LP filter applied to it ... this limits the frequencies - and harmonics of these frequencies - that it can produce.

Agree, gain structure and PEQ at these, at times tricky frequency points is also  super important.

Easy to wash out the upper frequencies with only a dB or 2 too much here, 40 through 70Hz. 

Edited May 16, 2024 by playdough

[Brash]

Thanks for everyone's feedback and advice.  I think I'm going to go with the a single SVS SB-2000 Pro and I have ordered a MiniDSP UMIK-1 to get it integrated as best as possible using the REW software. I've no doubt I have a lot of reading and learning to do regarding the set up but I consider myself a bit of a tinkerer so am looking forward to seeing what I can achieve. As mentioned early on, I can always add another sub if I'm not able to get satisfactory results.

[Keith_W]

Don't get a UMIK-1. Either get a UMIK-2 or a 48V Phantom Power mic. USB mics have separate clocks to the DAC and give you inconsistent timing information. Read John Mulcahy's (author of REW)  post here to see his experiments with a UMIK-1, UMIK-2, and EMM-6. Also, USB mics tend not to be calibrated, but proper calibration tends to affect the upper frequencies more, so you may not need a calibrated mic if you are only using it for subwoofer integration. 

 

Some people think that all UMIK-1's should be removed from the market. All that is required to make them give reliable timing is a little circuit change to include loopback, and they won't do it. 

 

If you enjoy tinkering you would loooooove the pain of adding a subwoofer. Basic adjustments will get you 90% of the way there but squeezing out the last 10% is where all the fun is 

Edited May 17, 2024 by Keith_W

[andyr]

18 minutes ago, Keith_W said:

Don't get a UMIK-1. Either get a UMIK-2 or a 48V Phantom Power mic. USB mics have separate clocks to the DAC and give you inconsistent timing information. Read John Mulcahy's (author of REW)  post here to see his experiments with a UMIK-1, UMIK-2, and EMM-6.

 

Very interesting, Keith!    As you know, I have the Dayton EMM-6 ... so it looks like I need to lash out and puy a UMIK-2.  

 

18 minutes ago, Keith_W said:

Also, USB mics tend not to be calibrated, but proper calibration tends to affect the upper frequencies more

 

The EMM-6 does have a calibration file (supposedly matched to your mic's serial no.) ... but how accurate this compensation is ... is unknown!

 

[Satanica]

39 minutes ago, Keith_W said:

Don't get a UMIK-1. Either get a UMIK-2 or a 48V Phantom Power mic. USB mics have separate clocks to the DAC and give you inconsistent timing information. Read John Mulcahy's (author of REW)  post here to see his experiments with a UMIK-1, UMIK-2, and EMM-6. Also, USB mics tend not to be calibrated, but proper calibration tends to affect the upper frequencies more, so you may not need a calibrated mic if you are only using it for subwoofer integration. 

 

Some people think that all UMIK-1's should be removed from the market. All that is required to make them give reliable timing is a little circuit change to include loopback, and they won't do it. 

 

If you enjoy tinkering you would loooooove the pain of adding a subwoofer. Basic adjustments will get you 90% of the way there but squeezing out the last 10% is where all the fun is 

 

I beg to differ, for the purpose of subwoofer optimisation, the inaccuracies of the UMIK-1 are irrelevant.
I'm pretty sure we've been over this before.

[Keith_W]

7 minutes ago, andyr said:

 

Very interesting, Keith!    As you know, I have the Dayton EMM-6 ... so it looks like I need to lash out and puy a UMIK-2.  

 

If you are going to "lash out", get a 48V Phantom Power mic Preferably an Earthworks. But if you don't feel like spending that much money, an iSemCon EMX-7150 is good. Or a Behringer ECM8000. 

 

 

7 minutes ago, andyr said:

The EMM-6 does have a calibration file (supposedly matched to your mic's serial no.) ... but how accurate this compensation is ... is unknown!

 

Mic cal files are not all the same. More expensive mics like the Earthworks are individually calibrated. Cheap calibrated mics are calibrated in batches. After a batch is manufactured, a number of mics are tested. They obtain the average and standard deviation of the mics in that batch and generate a cal file for all those mics. This will correct most mics but not all mics and might make some mics worse. 

 

To check if you have a batch calibrated mic, download another cal file from your manufacturer using a slightly changed serial number (e.g. 12346 instead of 12345) and compare that with your mic. 

 

 

This is the mic cal of my Earthworks M30 mic. You can see that the error is only a +0.3/-1.5 dB and it's mostly in the upper frequencies. 

[Keith_W]

1 minute ago, Satanica said:

 

I beg to differ, for the purpose of subwoofer optimisation, the inaccuracies of the UMIK-1 are irrelevant.
I'm pretty sure we've been over this before.

 

You're right, of course. A 300us difference in timing is irrelevant for subwoofer frequencies. But still, why buy a mic that has this limitation? 

[Satanica]

1 minute ago, Keith_W said:

You're right, of course. A 300us difference in timing is irrelevant for subwoofer frequencies. But still, why buy a mic that has this limitation? 

 

Because it's significantly cheaper than the one that doesn't.

[andyr]

6 minutes ago, Keith_W said:

 

If you are going to "lash out", get a 48V Phantom Power mic Preferably an Earthworks. But if you don't feel like spending that much money, an iSemCon EMX-7150 is good. Or a Behringer ECM8000. 

 

 

 

Thanks, Keith.

 

The Earthworks mic certainly is expensive!  And the EMX-7150 is similarly priced.  

 

What surprises me is that your 3rd recommendation - the Behringer ECM8000 - is only A$69 (from StoreDJ).  The UMIK-2, in comparison ... is USD195!

 

Can you tell me what "Phantom Power" means?  Where does the mic get its power from?

 

[Keith_W]

25 minutes ago, andyr said:

Can you tell me what "Phantom Power" means?  Where does the mic get its power from?

 

It's a condenser mic. It works like a capacitor. Sound causes the the plates to vibrate, changing the capacitance. For this to work, the mic needs to be powered by a 48V mic preamp. These can range from inexpensive (Focusrite 2i2) all the way up to several thousand dollars. 

If you get a Behringer ECM8000, send it to be professionally calibrated. This bumps up the price by about $150 (yes, it costs more than the mic itself). I own two ECM8000's. Compared to the Earthworks, these are lower sensitivity and do not go as high (Earthworks can go to 30kHz) and not quite as nicely built, although it's still a very nice microphone. The higher sensitivity of the Earthworks is a nice feature, but you could obtain the same by simply turning up the gain on your mic preamp.