[gguy]

What does the wall opposite the archway look like?

The opposite wall is closed off.

[mick wolfe]

Looks like there's now more space behind the Otica's compared to the original pic, but your listening position is now too close to the Otica's for proper driver integration. You would have to move the couch back a couple feet for starters. That said, not sure what room logistics/complications you're dealing with if you were to move the couch back.

[S Clark]

The opposite wall is closed off.

Of all of the bad options, that one might be the best of them.  I'd certainly try it and see. 
I've got a bad room to deal with, but yours takes the cake.  Good luck.

[gguy]

Looks like there's now more space behind the Otica's compared to the original pic, but your listening position is now too close to the Otica's for proper driver integration. You would have to move the couch back a couple feet for starters. That said, not sure what room logistics/complications you're dealing with if you were to move the couch back.

The placement of the drivers in the pic is how i normally have them, 4ft from the back wall.  I’m experimenting with some different seating positions, the current placement is at the 1/3 length mark.

[Badd99]

For a good WAF that will help with standing waves what about covering your front wall with

https://www.audimute.com/soundproofing-acoustical-products/for-walls/acoustic-panels/acoustiwood-acoustic-wood-alternatives

If you can swing jt with do both the sidewalls as well...

[gguy]

So I have been working on this for a few days now, starting out with just the NX-Otica's in the room.  After going through some tracks, the speakers ended up mostly in the same position I had them previously, about 4ft from the front wall, 5.5ft apart, and the LP about 3ft from the back wall.  Pulling the speakers in the room farther (to about 55") yielded a better soundstage but caused a bump around 200hz which muddied the sound.  At least at this point I have a general area to move the speakers and LP to get it dialed in even more, but I would like to get the two main subs set correctly before fine tuning.

After bringing the subs back into the room, I tried moving them around (even flipping them around) in the general area they currently reside and did some sweeps in REW.  The results were mostly the same, with a large dip around 60hz.  I ended up leaving the subs about 40" from the front wall (wall to baffle), I also moved them closer to the outside wall, which helped clean up some muddiness I was hearing having the sub cabinets too close to the NX-Oticas.  What did make a difference is the LP, having the LP 1ft from the back wall yielded a smoother response below 80hz, but choppier between 80 and 150.  Having the LP 3ft from the back wall was the opposite.  My final LP will likely fall between one and three feet from the back wall.


Next step is to dial in the subs with the mains, below is my current status with no integrating done.  I'm not sure what smoothing should be done to determine the -3db point, or what steps to take from here.

Plate Amp Settings:
PEQ off
Phase: 0
Volume: 12 oclock
Crossover: 80hz
Line In/Low Pass: AVR/12
Rumble Filter: Off
Extension Filter: 14/High Damping



The Rythmik L12's are here, but I am not going to break them out until this is dialed in.

[poseidonsvoice]

gguy,

You are making a good effort so kudos.

That being said, it would be best if you restrict the measurements to about 400Hz max (so that way you can still see how the subs blend with the mains) and also remove the 'variable' smoothing setting so you can see even more detail. No smoothing would be best but I understand it is hard to visualize the response with warts. So a good compromise is 24 dB/octave smoothing. I would then initially measure with mains only playing (and maybe you have already done that) and position them for the flattest response you can get from 400Hz on down. Next, add one OB sub stack, move it around, play with the filter settings, etc...then add the second OB sub stack when you are satisfied with the single OB stack + mains.

Each addition you make must look like an improvement in the frequency domain. If it makes it worse, something is off and you need to try again.

Some of the deep nulls you are seeing in the response is a room mode itself and it is near impossible to remove those without adding in room treatments. EQ/DSP will not help with nulls in the bass response (they do help with small peaks however). The other option is to move the subs away from the front wall listening position which may be impossible both from a visual standpoint and the fact that they are OB's.

Moving the LP position is an excellent idea and you should do so. I find that moving the LP position can make a tremendous difference. Ultimately, there is a compromise as you do not want imaging/staging to be maligned. You already have the main NX Otica's about 5 feet from the front wall.

As you can see there are many variables. Typically, for me, it takes several hours of measurements before I begin to 'understand' the room, and the interaction of all the speakers within that room. If you can enlist a friend it can dramatically help.

Best,
Anand.

[sunnydaze]

Dunno if you've done it yet, but have you tried the speakers set up on other walls?  Are you locked into this setup?  You are doing an awful lot of work, could be a losing battle with speakers setup on current wall.

If your living situation allows it, try a diagonal setup with speakers setup across a corner firing into the opposite corner.  This has worked well for me in difficult rooms.  No idea how OB take to this setup...never owned any.

But in general...and I hate to say it....but to me it just looks like too much speaker for the room.  Especially since to work properly, OB require much air around them.  You simply have no flexibility in placement, especially with the subs in that room.  5.5 feet of spread?  Seriously?           Everything just looks too "jammed in".

Not saying a smaller more traditional speaker solves the problem, but it would certainly allow for more placement options and the ability to get closer to boundaries and therefore achieve a better speaker spread.

Good luck!

[poseidonsvoice]

But in general...and I hate to say it....but to me it just looks like too much speaker for the room.  Especially since to work properly, OB compels much air around them.  You have simply no flexibility in placement, especially with the subs in that room.  5.5 feet of spread?  Seriously?     

Yes! 

Look at sledwards' build right here to see how much room they really need.

Best,
Anand.

[gguy]

gguy,

You are making a good effort so kudos.

That being said, it would be best if you restrict the measurements to about 400Hz max (so that way you can still see how the subs blend with the mains) and also remove the 'variable' smoothing setting so you can see even more detail. No smoothing would be best but I understand it is hard to visualize the response with warts. So a good compromise is 24 dB/octave smoothing. I would then initially measure with mains only playing (and maybe you have already done that) and position them for the flattest response you can get from 400Hz on down. Next, add one OB sub stack, move it around, play with the filter settings, etc...then add the second OB sub stack when you are satisfied with the single OB stack + mains.

Each addition you make must look like an improvement in the frequency domain. If it makes it worse, something is off and you need to try again.

Some of the deep nulls you are seeing in the response is a room mode itself and it is near impossible to remove those without adding in room treatments. EQ/DSP will not help with nulls in the bass response (they do help with small peaks however). The other option is to move the subs away from the front wall listening position which may be impossible both from a visual standpoint and the fact that they are OB's.

Moving the LP position is an excellent idea and you should do so. I find that moving the LP position can make a tremendous difference. Ultimately, there is a compromise as you do not want imaging/staging to be maligned. You already have the main NX Otica's about 5 feet from the front wall.

As you can see there are many variables. Typically, for me, it takes several hours of measurements before I begin to 'understand' the room, and the interaction of all the speakers within that room. If you can enlist a friend it can dramatically help.

Best,
Anand.

Hi Anand, adjusted measurements are below, these were taken with the LP one foot from the back wall.  I haven't gone too deep into the plate settings yet, as I am trying to understand how to establish the crossover point at the mains.  I mainly used my ears to adjust the back and forth position of the Otica's, moving the LP seemed to make the biggest difference in the smoothness of the low end, the LP at one foot from the back wall was the most ideal in the current state.

Dunno if you've done it yet, but have you tried the speakers set up on other walls?  Are you locked into this setup?  You are doing an awful lot of work, could be a losing battle with speakers setup on current wall.

If your living situation allows it, try a diagonal setup with speakers setup across a corner firing into the opposite corner.  This has worked well for me in difficult rooms.  No idea how OB take to this setup...never owned any.

But in general...and I hate to say it....but to me it just looks like too much speaker for the room.  Especially since to work properly, OB require much air around them.  You simply have no flexibility in placement, especially with the subs in that room.  5.5 feet of spread?  Seriously?           Everything just looks too "jammed in".

Not saying a smaller more traditional speaker solves the problem, but it would certainly allow for more placement options and the ability to get closer to boundaries and achieve a better speaker spread.

Good luck!

I did think about having a diagonal setup, but ultimately would be sitting right on top of the speakers.  I have gone through this with a previous setup, which was more conventional, with the results being the same.  Here is a thread I started prior to purchasing the speakers:  https://www.audiocircle.com/index.php?topic=166789.msg1771584#msg1771584.

[mlundy57]

I use 1/6 octave smoothing and a range that allows the major increments on the scale to be 5dB apart with minor gradations 1dB apart to make it easier to read for integration.

Also, the crossover point is where the Oticas are -6

[EdwardT]

The 12 foot dimension in your room is almost a perfect wavelength and 1/2 wavelength for those big low end peaks, that’s your huckleberry. There's not really any solving that with dsp.

[poseidonsvoice]

gguy,

So you clearly have modal issues like all rooms, and here it appears to be in the 40Hz area (and several other areas as well). You can see that the Otica's which typically rolloff at 60-70Hz or so, do not do so in this room. There is this big boost/null below that point. You need to separate speaker from room influences.

One trick you can try is to take the mic and place it very close to one of the woofer cones on the Otica's (or in between the woofer cones if you want). Something like 1 inch or less. That way, you minimize the room influence as much as possible. Next, just play frequencies from 400Hz on down and see what the actual rolloff the Otica's are.

You can do the same with each of the subs as well.

This also verifies that you built these speakers properly.

I always do a close mic measurement of any speaker I built (or purchased) to see if there are any unforeseen anomalies. I also do an impedance/phase measurement.

mlundy makes good points and sometimes we need to add smoothing to distinguish the forest for the trees; but once we do, we can take the analysis much further and minimize the smoothing as much as possible.

I would be curious to see what the F6 of each of your Otica mains are at this point with a close mic measurement. It can clue you in on a good crossover starting point for the subs.

You can use this calculator to see all your modes:

https://amcoustics.com/tools/amroc

Good luck!

Best,
Anand.

[DannyBadorine]

Dunno if you've done it yet, but have you tried the speakers set up on other walls?  Are you locked into this setup?  You are doing an awful lot of work, could be a losing battle with speakers setup on current wall.

If your living situation allows it, try a diagonal setup with speakers setup across a corner firing into the opposite corner.  This has worked well for me in difficult rooms.  No idea how OB take to this setup...never owned any.

But in general...and I hate to say it....but to me it just looks like too much speaker for the room.  Especially since to work properly, OB require much air around them.  You simply have no flexibility in placement, especially with the subs in that room.  5.5 feet of spread?  Seriously?           Everything just looks too "jammed in".

You're definitely correct.  That room is far too small for those speakers and you can see it in the frequency response.  If there is that much build up around 40Hz (I'm guessing the room is around 14'x14' which would give you that kind of build up) then the subs are just going to add more problems, which is why one or two subs is more than enough.  Ultimately, it's just far too much wall reflection for the low end which will lead to big humps in some frequencies and nulls in others as seen on your graph.  Some room treatment might help a bit but low frequencies from large drivers need room to breathe or they just bounce off of the walls, hit each other and cancel out or sum in unpleasing ways.  Sorry to be negative but in a room that size you need smaller speakers and only one or two subs.  Or you can just jam as many speakers as you want in there and turn it up.  It might not sound clean but it will be awesome.

Not saying a smaller more traditional speaker solves the problem, but it would certainly allow for more placement options and the ability to get closer to boundaries and therefore achieve a better speaker spread.

Good luck!

[sunnydaze]

Danny.....
your reply got buried into the original post quote.  For clarity I broke it out for you.  Hope you don't mind.

But in general...and I hate to say it....but to me it just looks like too much speaker for the room.  Especially since to work properly, OB require much air around them.  You simply have no flexibility in placement, especially with the subs in that room.  5.5 feet of spread?  Seriously?           Everything just looks too "jammed in".

per DannyBadorine:

You're definitely correct.  That room is far too small for those speakers and you can see it in the frequency response.  If there is that much build up around 40Hz (I'm guessing the room is around 14'x14' which would give you that kind of build up) then the subs are just going to add more problems, which is why one or two subs is more than enough.  Ultimately, it's just far too much wall reflection for the low end which will lead to big humps in some frequencies and nulls in others as seen on your graph.  Some room treatment might help a bit but low frequencies from large drivers need room to breathe or they just bounce off of the walls, hit each other and cancel out or sum in unpleasing ways.  Sorry to be negative but in a room that size you need smaller speakers and only one or two subs.  Or you can just jam as many speakers as you want in there and turn it up.  It might not sound clean but it will be awesome.

[gguy]

I would be curious to see what the F6 of each of your Otica mains are at this point with a close mic measurement. It can clue you in on a good crossover starting point for the subs.

Here are some measurements I took of the low and mid woofers for each side.  The 40hz bump was still picked up even when up close.
*Deleted*

Danny.....
your reply got buried into the original post quote.  For clarity I broke it out for you.  Hope you don't mind.

per DannyBadorine:

You're definitely correct.  That room is far too small for those speakers and you can see it in the frequency response.  If there is that much build up around 40Hz (I'm guessing the room is around 14'x14' which would give you that kind of build up) then the subs are just going to add more problems, which is why one or two subs is more than enough.  Ultimately, it's just far too much wall reflection for the low end which will lead to big humps in some frequencies and nulls in others as seen on your graph.  Some room treatment might help a bit but low frequencies from large drivers need room to breathe or they just bounce off of the walls, hit each other and cancel out or sum in unpleasing ways.  Sorry to be negative but in a room that size you need smaller speakers and only one or two subs.  Or you can just jam as many speakers as you want in there and turn it up.  It might not sound clean but it will be awesome.

This may be the case, but this setup does still sound better than anything I previously had.  I tried to do my homework before making the investment on this setup, the feedback I got from users on this forum, and from GR, indicated they should work great in my room, but those are only opinions.  The reality is that the bass in this room has always sucked, looking back at some previous posts of measurements I took, that 40hz bump has always been there.  I have had a minitower/dual sub setup and a full range tower setup prior to this one, both left me chasing something more.  I don't know if going backwards, or sideways, will solve the problem.  I either have to live with it, or fix the room.  At this point, I just want to get the most out of what I have right now, whatever the result.

[poseidonsvoice]

gguy,

Yup, big 40-60Hz room mode. So much of it that even a close mic measurement of the Otica's can't eliminate it. Hello room treatments or different room.

As can be seen here, an OB setup requires quite a bit of work, and it also requires room treatments, it isn't a panacea unfortunately. I learned a ton when I helped setup sledwards' system in his LARGE room.

How does the system sound with JUST the NX Otica's, i.e. shut the OB sub stacks off.

Best,
Anand.

[Tyson]

You need bass traps and EQ.

[gguy]

gguy,

Yup, big 40-60Hz room mode. So much of it that even a close mic measurement of the Otica's can't eliminate it. Hello room treatments or different room.

As can be seen here, an OB setup requires quite a bit of work, and it also requires room treatments, it isn't a panacea unfortunately. I learned a ton when I helped setup sledwards' system in his LARGE room.

How does the system sound with JUST the NX Otica's, i.e. shut the OB sub stacks off.

Best,
Anand.

Sorry, my last post was just the NX-Otica Drivers, and not the subs,  see below.  I'm not sure why the mid drivers measured louder, I could have screwed something up with the measurements.  The FR's below are an average of all of the measurements by driver type.



When I restarted this process, I started with just the NX-Oticas in the room, but constrained my movements assuming I still needed to fit the subs in (also relying more on my ears than measurements).  I'll run it back without the subs and see what I come up with, this time using the RTA.  The Otica's did sound good on their own, albeit with no low end grunt.  Last night I did some listening with the subs on, and I did notice some improvements across the board, mainly less mudiness, so at least I am getting somewhere. 

I know room treatments are unavoidable at this point.  I am looking into DIY tube traps for the corners and absorption panels for behind the LP, these can be easily taken down and put away when not in use.  The ceiling will be a bit tricky, I'm not sure what to do there, if anything.  GIK suggested hanging (4) 244 full range panels above the speaker side, close to the center of the room.

[Early B.]

Hey OP -- if you're gonna throw more money at the problem, the next cash outlay should be hiring an acoustic engineer to give you professional advice.