2 * BK XLS400 or one SVS SB2000 Pro?

Another set of measurements with front LR speakers with and without subs, set at large or 90Hz crossover. Audyssey on and off. I'm puzzled as to:
1. Why the measurements are almost identical between 20 and 15hz whether or not subs are on. Is the room and/or speaker positions the cause?
2. The cause of the dip at 100Hz which is there to one extent or another with or without subs or crossovers. I tested 40hz up to 150hz, best around 120Hz. Any suggestions as to how to improve that?
3. The null between 45 to 80Hz with the front LR speakers set on large. Ignore as the subs fill that in with Audyssey on? or could anything be done to improve that?

Apart from that it looks quite flatish to my eyes with Audyssey on in the frequencies that the subs operate in.

front lr.jpg
 
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1, My opinion on matters below 20hz is it doesn't matter, you feel not hear, and you would need some serious dB to actually feel it. If you've the space and budget for big subs to make you feel 15hz, then I'm sure it's awesome. But, there's bugger all content that low anyway, and in most modest setups it seems a distraction.

2, that's being caused by speaker position (in relation to listening). I believe the issue is one called SBIR, essentially a reflected wave is coming to you out of phase as that of the direct sound, and causing a cancellation. Rear, side walls obvious choices, but could be ceiling or floor too. I've got the same issue at almost the same point (my speakers are about 40cm from the walls), and potentially I'm thinking about GiK Scopus T100 traps behind the speakers. I am however getting a lot of conflicting info on how to treat it at the moment. It's looking like I might have to just buy a couple of different types of panels and see, because I can't move my speaker or listening positions.

3, the only thing that really matters is the final result with subs. As long as the subs are crossed over below the point you can identify them that is. I'm mostly a 2ch guy, and I've recently bunged my speaker ports for the reason that it with all things considered it simply sounds better to have the sub play the lower stuff. (i.e the bungs effectively roll the speaker off early, and the sub picking up the bass with PEQ allows tighter control).

Your corrected response is overall good though, I think it's being flattered slightly by the scale you've used mind. From what I have seen standard convention is to have the vertical scale at 5dB.
For my preference the only thing I would like on that is to build in a house curve (I'd like another 10dB on the bottom end), I'd do some compression sweeps next and see how much headroom you have.
 
1, My opinion on matters below 20hz is it doesn't matter, you feel not hear, and you would need some serious dB to actually feel it. If you've the space and budget for big subs to make you feel 15hz, then I'm sure it's awesome. But, there's bugger all content that low anyway, and in most modest setups it seems a distraction.

2, that's being caused by speaker position (in relation to listening). I believe the issue is one called SBIR, essentially a reflected wave is coming to you out of phase as that of the direct sound, and causing a cancellation. Rear, side walls obvious choices, but could be ceiling or floor too. I've got the same issue at almost the same point (my speakers are about 40cm from the walls), and potentially I'm thinking about GiK Scopus T100 traps behind the speakers. I am however getting a lot of conflicting info on how to treat it at the moment. It's looking like I might have to just buy a couple of different types of panels and see, because I can't move my speaker or listening positions.

3, the only thing that really matters is the final result with subs. As long as the subs are crossed over below the point you can identify them that is. I'm mostly a 2ch guy, and I've recently bunged my speaker ports for the reason that it with all things considered it simply sounds better to have the sub play the lower stuff. (i.e the bungs effectively roll the speaker off early, and the sub picking up the bass with PEQ allows tighter control).

Your corrected response is overall good though, I think it's being flattered slightly by the scale you've used mind. From what I have seen standard convention is to have the vertical scale at 5dB.
For my preference the only thing I would like on that is to build in a house curve (I'd like another 10dB on the bottom end), I'd do some compression sweeps next and see how much headroom you have.
Thanks for your comments. Graph at 5dB vertical scale doesn't look so good, let alone at 2dB...:(

What would be the best crossover between 80, 90,100 or 110Hz?.
Seems swings and roundabouts. 110Hz crossover raises the 100hz dip at the cost of lower 40-70Hz (-3dB) while 90Hz gives the best 40-70hz at the cost of worse 100hz (-2dB) and 140Hz dips.

I'll try bunging the front LR ports if I can find the bungs and see if that makes any difference with the 100hz dip (and/or bung one but not the other). Moving the front left just a few inches made a huge difference in eliminating a couple of bad nulls which no longer appear, perhaps the right one might benefit from that too.
xovers5.jpg


xovers.jpg
 
Can you change the scale to logarithmic as well? Should be one of the buttons at the top right.
 
I'd go for more output lower down and take the hit on the null. You're unlikely to hear it as it's very narrow. Most content isn't one frequency at a time.

Your low end is rolling off quite heavily with the green line.
 
Yeah 90hz crossover for sure in my opinion.

The bungs are unlikely to make a difference to the 100hz null, I found all it did was alter much closer to the tuning freq of the ports, my KEF have 2 ports and I tested all combinations - but by 120hz it was negligible and the null was still the null in essence.

147429575_10159674898229644_3081459978893455116_o.jpeg


(this is the effect of bungs alone. Also it's a 2ch output so no room correction other than some PEQ on the sub & set with a 40hz LR24dB crossover)

To fix a 100hz null, you're going to need to move the speaker (maybe listening spot), or get the room treated. Like you I could do with a minimum of 5dB and ideally 8-10dB at my similar null.
I'm pretty sure I've worked out the paneling I need this weekend without making the room look like a studio! But it's not cheap as it requires multiple products... cheaper to move the speakers if you can... :)
 
Check out Mafia panels if you’re just after plain panels. I did my whole room with under £300 for seven panels.
 
Check out Mafia panels if you’re just after plain panels. I did my whole room with under £300 for seven panels.
Thank you but unfortunately plain panels won't pass muster. As it's a lounge there's a stringent aesthetic commission to pass, which involves in summary Acupanel kitting out the front wall whilst incorporating a few GiK 244's with range limiters, then the side wall is getting some of the Impression series wood ones. The 244's also need to be a custom size!
But it should look awesome and be functional, so if I can kill 2 birds so to speak, then I can use a little man maths to deflect the cost from being pure 'hifi' related....! :)
 
Yeah 90hz crossover for sure in my opinion.

The bungs are unlikely to make a difference to the 100hz null, I found all it did was alter much closer to the tuning freq of the ports, my KEF have 2 ports and I tested all combinations - but by 120hz it was negligible and the null was still the null in essence.

View attachment 1472830

(this is the effect of bungs alone. Also it's a 2ch output so no room correction other than some PEQ on the sub & set with a 40hz LR24dB crossover)

To fix a 100hz null, you're going to need to move the speaker (maybe listening spot), or get the room treated. Like you I could do with a minimum of 5dB and ideally 8-10dB at my similar null.
I'm pretty sure I've worked out the paneling I need this weekend without making the room look like a studio! But it's not cheap as it requires multiple products... cheaper to move the speakers if you can... :)
Yep bungs made little to no difference at all for my setup..
I will not moving the speakers for a while as moving a sub last night has done my back in. Not too seriously as I can still walk around OK but enough to let me know if I do it again I'll likely be in big trouble. However unless I completely rearrange the room any speaker move will be a matter of inches forward/back left or right at most.

So I resorted to moving the mic position around 6-8 inches left or right and forwards. While mostly detrimental it does show the 100hz dip can be mostly eliminated by listening position move. But that just makes the 40 to 70hz dip much worse.
blue = move right 6 inch and forward 6 inch (worst 40-70, best 100hz)
gold: 6 inch left (better 40-70hz) crap 100hz
green = original position giving goldilocks like measurements in the middle of the above.

There is probably potential here to get better results by doing XT32 eqs for a number of mic positions and switch between them with the editor app and remeasure with REW. As it was, all of the positions were within the XT32 6 position measuring box.

So to return to my original question given the limitations of the room and available speaker positions would I get any benefit from a new subs(s)? And if so where would it be frequency wise? Just more SPL at 40hz downwards where the current subs drop off?

mikemove.jpg
 
Yeah running room EQ on each mic position would optimise it for that position, but the fundamental problem will still exist. Unfortunately this is nothing unique to your setup, every room has modal problems below 300hz, and the smaller the room usually the worse it is (can be up to 500hz I recall in smaller rooms). You just need to find the best balance of locations, and multi sub is usually the best way to a broaden the response (as we've discussed as long as you have the locations free in the room), which also helps in the the left/right mic movement problem too.

So to return to my original question given the limitations of the room and available speaker positions would I get any benefit from a new subs(s)? And if so where would it be frequency wise? Just more SPL at 40hz downwards where the current subs drop off?
As a rule if a sub location remains the same, then bass will still propagate in the same way and the room will still interact in the same way. So you technically only gain in more output, but you can potentially create a flatter response due to it.

That total output maybe something you need, depends on listening levels, but your graph does look like some more output from 40hz down would be welcome.
However with more output higher up it can be useful as you can EQ down to an overall flatter response, I wouldn't expect miracles from it all, and also be aware any nulls will still remain as voids in the response at the same points.
I.e if you raise overall the total spl output, then EQ down output either side of a null, it won't end up flat...the null will still exist where it is :( Been there, got the t-shirt!!
 

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