Do I need a sub woofer to match my ATC SCM11s

No doubt in most any room with most any smaller monitor speaker, no matter how good,  adding a sub or two and integrating it well betters the experience by extending the low end that is largely missing otherwise.

If you do it right you should as good off or probably even better off than if you simply invested in a pair of good quality large heavy expensive full range speakers.

Hi mapman,

    Don't you think it's more difficult to optimize the positioning of large full range speakers in relation to the listening seat since the midrange, treble and bass drivers are all located within a single cabinet? 
     I don't consider it difficult to position large full range speakers to optimize the mid/treble frequency response and imaging at the listening seat; it typically just takes some experimenting with the distance between the speakers, distance out from the front wall, distance from the listening seat, toe-in and often some room treatments along the side walls to control first reflection points. 
     Once the large speakers are optimally positioned for midrange/treble and imaging, however, the bass response at the listening seat cannot be optimized because the position of the bass drivers cannot be independently located within the room to do so.  The bass drivers are locked into position, usually at the bottom section of the large speaker cabinets below the midrange and treble drivers.  
     I agree with you that adding a sub or two to a system that uses small monitor speakers betters the experience by extending the low end that is otherwise missing.  
     But I disagree that a pair of good quality. large and expensive full range speakers would be superior to a pair of good quality, smaller and less expensive monitors on stands along with at least a couple of good subs.  The main reason being the ability of the monitor system to independently optimize the mid/treble/imaging at the listening seat with monitor positioning and the bass response at the listening seat with sub positioning.
     Of course, I think a pair of good quality, large and expensive full range speakers along with at least a couple of good subs independently positioned would be even better.

Tim

Why not just have an ATC subwoofer?

@jeres8860 , Your SCM 11s are lovely little two way monitors with very capable drivers. Adding subwoofers correctly to this type of loudspeaker takes them to an entirely different level of performance even better than most large three way floor standers. Because of the very small enclosures they have less trouble with enclosure resonance and diffraction leading to more precise imaging. Adding subwoofers can drop distortion dramatically at volume and increase the headroom 10 dB. That is twice as loud! That is like getting an amp that is three times larger.

Doing this wrong will just f--- things up. To do this correctly you have to get two subwoofers. Place them just inside each SM 11 up against a wall and try to keep all the speakers on the same radius from the listening position. I suggest 12" drivers. If you are a handy guy get kits from Parts Express and use the money saved to get a digital preamp with bass management. The MiniDSP SHD is only $1300.00 To drive the subwoofers get a commercial sound reinforcement AB amp like a QSC. It has to have a balanced input. If you want to go ahead with this and you have any trouble feel free to message me. Believe it or not, all this will cost you less than one 13" JL Audio subwoofer!  

I have a different take, The SCM 11 are not bass light or bass shy, they are actually the "warmest":(the most bass in relation to the midrange) of ALL the small ATC 2 ways. So the bass light impression of the SCM11 shoild not be, I suspect its all "room" related. The fact that sub seemed to "solve" the issue emphasizes the point. There could be multiple reasons for this, but lets start with the basic Idea that a room under 30 foot in dimensions is incapable of supporting a 32 hz wave (32 hz = 35 foot long wavelength).

Most speakers will be bass light in a normal size (12-20foot dimension) room. This is NOT solved by stand mount vs floor mount, or other myths. This issue is msot often solved with multiple small subs used a low level. 4 small 10s would not be wrong- they can even be small cheap subs. Without high passing your SCM11, adding subs [that are not ported] low passed in at somehwere around 60-90Hz could be the best solution. This would provide even bass throughout the space and also enable you to set the balance of sub to main to your taste.  I would not get overly concerned about LFE unless the min application fo these is film.

You will get quite a few with different ideas here, but this idea is one of the solutions we put in play in studio control rooms all over the US when they have the same problem, small dimensions.

Brad

 

Brad

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