Subwoofer Positioning & settings

I've recently bought a BK XLS200 DF subwoofer, it is a sealed unit.

I've experimented with positioning the subwoofer in different locations and have found that the best position for the sub is in between my main speakers.

Is it unusual to position a subwoofer this way as I see some have them positioned in a corner ?

I've spent considerable hours over a few days adjusting the position of my mains speakers and subwoofer. The advantage I've found is that I am able to bring my main speakers into the room further away from the rear wall creating a better soundstage. The subwoofer is then compensating for the slight loss of bass with the main speakers away from the wall.

I've not used any software or measuring equipment, I've just trusted my ears to establish the optimum position, but wonder if it is u usual to find the best location for the subwoofer is between my main front speakers.

The room size is approx 14 foot x 13 foot, I only use two front speakers which are Rega RX3.

As for the crossover I have it set at 80 with the Gain at almost 10 0'clock, the Phase I have at approx 140.

 

I forgot to mention also that I have the subwoofer connected at high level to the connections at the back of my Heed Obelisk MK2 amplifier

 

Every room is different so really no way to guess where it may sound best without some exhaustive measurements. Sounds like you did good. The only thing I would advise is to try and set the crossover point as low as you can, and maybe use some lightweight filler (like lambs wool) in the ports of the main speakers to slow their rolloff for better integration, which is what I do, along with having the main speakers well away from the walls. I use a second order rolloff on the woofer and run the mains full, and generally have the level pretty low. My subwoofer wound up one of the side walls, but I don't have the ability to try it between the speakers. The subwoofer will become more directional if you cross it over too high, and also may have some cabinet resnances that will get excited more. Just something to try, there's really no best way to do it, just experiment, and maybe make some notes.

 

Your ideal subwoofer placement will be room dependent, I think the rule of thirds is solid physics so I have mine like my speakers, about a third into the room. Also a third from the sidewall. I crossover about where my speakers drop off. This plus room treatment has eliminated most node problems for me

 

No it's not usual AFAIK, wished I could position it between my floorstanders as I did on my previous home. Now, corner, and it was a bitch to set up.

 

If you had a mono speaker and were listening to the Beatles mono masters, that's where you'd put the main speaker. Makes sense as a location for a mono sub.

However, since the low bass frequencies can't easily be localized, one can take advantage of wall and corner placement to boost the output, and additionally may leave you with less room nodes, as the pressure wave simply radiates out from that point without cancellations before you hear it. If it's too far off to the side, you can get more sound pressure in one ear than other, which is detectable and odd-feeling, and if the sub makes non-program noise (port, rattling, distortion) or is crossed over too high, you can also start to locate the source of sound in the room.

 

Thanks for the replies, it's been quite an interesting time setting up the subwoofer.

So far I have tried with the subwoofer positioned between my front speakers in front of my hifi system which is also between my front speakers. As in the photo below.

Even though it seemed to blend well with my main speakers, I found the actual position of the subwoofer awkward in the position that it was in.

So this evening I have made significant changes to the layout of my system.

I now have the speakers moved away from my main system so that the only thing between the front speakers is the subwoofer (see picture below)
In this situation I have found that I need much less gain and also the cross over point at 65 instead of 80 in the original set up. Although as can be seen I need longer length of speaker cable.



It's interesting how the set up of the subwoofer needs adjusting dependant on the various points I have placed it. I have the phase set at about 150 which seems to suit it.
I am going to persevere with adjusting by ear for the next few days. My guess is I will have to adjust further once I replace my speaker cable with a more suitable length.

 

I like your lamp table

But seriously, I recently tried a subwoofer in my set up and the best sounding location was in between the speakers. It sounds best, but I'm not loving the look. I also have my equipment off to the side with just the amp behind the subwoofer.

edit: My description seems lacking so here's a pic:

 

If that’s the spot then that’s the spot.
I’m lucky my living room is rectangular and the corner works perfect. The kitchen is very boomy
I usually do the subwoofer crawl if it’s a difficult room.

 

Is the sub a bottom firing sub? If so I find that placing it nearer the back wall tends to flesh out the sound some, although that also depends a lot on things like what the walls are made of, is it suspended or has a concrete pad underneath, etc.

Anyway, I'm glad your ears are telling you you got things right. No measurements can beat that.

 

I place my Martin Logan Depth sub 4" from the back wall and face the speakers to the wall to disperse the bass more and make it harder to detect even though it's Xover at 45Hz. It's also 180 out of phase.

I found that even at low Xovers the sub can be detected on some tunes.

I'd also suggest you Xover at a lower point. Optimally the Xover should be about 20 Hz higher than the lowest Hz your speaker is rated for although in room responses do vary the low point. That is why I Xover at 45 because my speakers go to an in room measured 23 Hz.

 

Subs are highly room dependent. Unless your listening room is devoid of furniture, no matter where you put it, there will be one sweet spot and several spots that aren’t so sweet.

 

My single Martin Logan Grotto is between my speakers too. I use a combo of listening and measuring with a test cd and spl meter from 200 down to 20 hz. Low pass at 65hz and my mains roll off steeply at 80hz. Too much overlap higher than that. I also have my sub level potted down to match spl levels with my mains. I don’t detect any directionality on any material.

 

With regards the Phase Setting, due to having my subwoofer in between my speakers,
would the likely phase setting be 0 degrees or near to 0 degrees.

I have the option to adjust the setting gradually from 0 degree to 180 degrees, and I only have two front speakers, there are no rear speakers.

Thanks again.

 

No way to tell, it depends on the main speaker crossovers and amplifiers, as well as the type and steepness of the filter in the subwoofer and its amp, and the driver phase responses, along with the actual position of the sub in relation to the mains. You can use a test CD and try adjusting phase for maximum volume around the crossover point as a start, or if you have a mic and pink noise source, look at the spectrum. Lots of tools available, but ultimately you just have to experiment and listen.

 

Maybe but probably not. There is no guarantee that the mains will be at zero phase where the sub is blended in. Very few speakers are time and phase coherent. Plus adjusting the sub's crossover point will move the sub's phase.

Listen and measure to find out what works. Rarely will zero work.

My sub is on the same plane as the mains, located between the mains and the phase is off around 20 degrees to blend them well.

 

vinylsam,

I would help if you post your system in your user profile. If we understand your components better, then we are in a better position to comment.

You tower speakers look like they should go down to 50-Hz. If so, try you sub at 50-Hz.

The lower you play your sub, the less localization you will have. This will not be an issue if you have the sub positioned in the center between your two front mains, but it does help if they are placed off to the sides.

80-Hz. bass can be easily localized, 40-Hz. bass, not so much. Always try to set your sub as low as it can go.

 

Thanks I will do the update on my profile later, thanks for letting me know about that.
In the meantime my system is
Linn Sondek LP12 with Sole Subchassis & Analogue Origami Modified Rega RB251 tonearm & Heed Orbit 1 turntable Power Supply
Denon DL110
Heed Obelisk MK2 Amplifier
Heed Questar MM Phono Stage
Heed Q PSU power supply for phono stage
Rega RX3 Speakers also Epos ES 14 (in use occasionally)
Naim CD5x CD player and Naim Flatcap power supply

 

Thanks for the recommendation. I thought it post a picture of what I've arrived at being the best settings.
Surprisingly to my ears I've found the best crossover frequency at approx 90hz
With the Gain at almost 10 o'clock and the Phase at just after 10 o'clock on the dials.

I did try it with the crossover at various other points such as 50hz , 60hz but it didn't seem to support the same frequency as my main speakers.
With the frequency at about 90hz the bass is more tuneful and maintains a Timbral quality to the instruments, it just sounds more natural. Also I'm not getting any harmonic distortion with these settings.

Not sure if the settings I have are unusual but it seems to be working for me.

 

Same with my setup, and my floorstanders go down to 39 hz ! So I get full-range sound from my speakers -which is often enough for a lot of recordings- and engage my sub only for recordings lacking bottom end. I also find 90hz adds the perfect reinforcement. Are you running your mains full-range or just letting the sub take care of the bottom end ?

 

My are run at full range. I have the subwoofer cable connected to the back of my amplifer speaker connections, using the high level option.

 

Me too

 

My sub filters 150 Khz when connected to the speakers. So I run separate sets of cables to the mains and sub. If you feel the sound is more accurate or fuller, or just more to your liking, don't mind the rules about the overlapping of frequencies. Sometimes reinforcing the bass that your mains already produce is more satisfying than merely extending the response (which is done at any crossover setting anyway)

My mains go down to 39 and my sub is set at 90. That's a pretty beefy overlap so I engage it when the recording begs for it, kind of using the sub as a big loudness device. Happy as a clam.

 

Mine is set at 65 or a little higher. Seems good. Oh then there’s phase. 90

 

Only thing that concerns me, is that I have enough free room someplace so I'm not running it inches from the turntable. Of course I keep my sub quiet, so it's only perhaps noticed in a grand burst of sound. Otherwise it's rolled-off to just take up slack from the bottom of the fronts, and low enough that I have to kneel right down to it to ascertain it's even performing. I don't put it there to be "heard".