Subwoofer from Floor Standing Speaker distance

Quick question, does anyone know if there is an issue with having a sub being about 3 inches from my floor standing speaker, I have limited space and needed to push them closer together to see if a rack would fit between the main speakers.

I may end up inverting sub and speakers when the stand comes as my Roon ROCK would be too close to the big magnet of the sub currently. The doorway poses a challenge too.

If you are crossing over low (50-60Hz), then I would let the room dictate placement. Crossing over higher (up to 200Hz), then the subs need to be close to the mains due to localization and phase coherence issues. Hope this makes sense!
I don’t think your sub will cause an issue being that close to your mains if you have to do it- only way to tell is by listening and/or measuring your frequency response at different sub-mains positions.

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Thanks so much. I am crossing over at about 70 ish (9 clicks on the REL is about 40.5 above the 30 min setting).

As long as it’s not hurting anything and I can make it sound alright that is the important part.

Thanks again!

I was doing the same thing for a while. And letting the room dictate REALLY helped me. I listened to Pauls explanation of putting the sub in seating position and finding the best sound in the room and putting the sub there. Just saying even though I know that wasn’t actually your question.


also base your cross over on the specs of you full range speakers. You probably know that but…

I mains say they go down to 46, so I set the sub to 50…

Hope this helps and is not annoying

Hi Tony,

Not annoying at all! Thanks for the advice I do need to adjust it a bit, I need to do some measurements and see what things look like. I have tried a few and can’t tell what the heck they are telling me.

Will let you know how it goes if I find something that I can understand!

You mean spec measurements on you speakers? What measurements?


Sorry meant acoustical measurements of my room to understand if I am way over doing the bass

How big is your room? What mains are those. Do you have 2 subs? Reason I ask is my gut tells me you’re gonna get a lot of bass in that room. I moved an old set of speakers to hard wood and the bass increased fairly dramatically.

The room is roughly 13x13, and yup, had to turn the subs down pretty far to level match, by ear to the speakers. The speakers are the ATC SCM40 (the newer version not the 2005ish version)

Typical audiophile: nice gear in a poor (smallish/square) room.

Who told you that you needed a sub (let alone a pair of subs) in that room with the ATC SCM40?

Recommend trying a non-symmetrical layout, centered very roughly in the left corner and adding GIK 244 absorption panels on two adjoining walls to break up the echo (that would be driving me mad).

Read Floyd Toole’s “Sound Reproduction”. In it he describes bass behavior in a room as behaving like waves in a shallow bathtub. As you move your hand lengthwise the waves hit the end and bounce back until they encounter another wave, where they cancel, add, or just interfere. So you want the bass generators (speakers/subs) to NOT be side by side, and instead to be dispersed even flipping phase on one of the subs.

So recommend moving the left sub farther back in the room, locate by putting that sub (and disconnect the other while doing this) in your listening position, then crawl around the room to find where it sounds the loudest/clearest - that’s where it should go.

@jlm Thanks for the detailed instructions. Unfortunately the hobby has gotten the best of me in the only room in the house that we really have for it, which is my office. I do like the idea of adding in the GIK panels and will see what I can do about rearranging the subs, there is a bit I can do with location, but unfortunately I work from home if not at a client site so the primary purpose of the room is still as an office.

I may have followed Paul’s advice on the two subs too literally in such a tiny space. But I have cut the typical REL gain in half in both by only using one positive wire not tying both together for each separate sub. But I do love the results when I listen to something like Bruce Hornsby’s version of Madman Across the Water. Sounds crazy good.

I’ve got SF Bookshelf speakers on stands. Here is the best sounding position for my set-up. I got them away from the corner of the room. Did not like that place for them. Found the inside corner of the main speaker stand base to be the best sounding.

My guess is I will / should move my subs from the corners as you have done to minimize the amount of bass reinforcement. I just cant until I get the new stand (or I could but that would mean putting Roon ROCK somewhere else that I need to figure out with longer power cable for it.) It also means the wife is going to see the big speaker in the doorway and lose it, good times…

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That was my reason for doing the modeling in VISIO to make sure I had room for subs and the rack would hold it all in a small enough footprint. I also measured the distance from sub to the BHK300 pair that will straddle the rack in the future configuration and they fit and so does the XLR 0.6m cables…:+1:

Wow. Really nice utilization in that room. How big is it - apologies if I missed it.

12ft X 10ft X 21ft