Lots of bass at walls, lack of bass in center of room/listening position

Try turning the subs down. Like whispering at 40 hz.

i’ve had the EXACT same issue w huge dip at 80-100hz by mandated listening position. completely solved w a smaller driver(very fast) sub. The b&w db1 is a true system changer. it will play at 80-90hz without any detection issues. i place it just inside left speaker. it has several phase choices which are very easy to hear allowing perfect match w mains. in my room 270 degrees is the correct setting for me. neither 0 or 180 worked well. try it as you will be overwhelmed at the seamless integration. 

Actually this seems to collapse my sound stage and squash imaging towards the center as well

Hey just made a discovery.

Just played around with the roon dsp, i hit invert on my left channel, and all of a sudden the bass came out of nowhere, was focused, intense and powerful and evenly distributed as I lean left and right. When you turn invert off on the left it weakens and becomes much more diffuse. So maybe i have something wired incorrectly? Only thing is if i leave invert on, i sometimes get some popping and crackling so sounds on the inverted channel.

I had an issue with my room few years ago, bass was not filling up around my sitting area. Tried many ways to get them filled up by moving sitting position, speaker placement and I was even contemplating of getting a sub in. After I was introduced by Micahel Green with his Room Tune pillows and consulting him I did some placements of his room tune pillows in my room and finally presto bass is now more around my sitting position. Eventhough I'm not getting super low notes as I'm using bookshelf speakers but it was night and day improvement for me. 

@smodtactical,

I have been down your path many times over the years. Experiment, experiment, and learn from others for sure. So many factors play into getting good bass response, and as others have mentioned, normally, it’s complicated to get even bass distribution throughout the room with room modes playing with your ideal settings and affecting the listening quality. I have learned to use the Velodyne SMS1 Sub EQ for my sub integration needs. Well, lately,  not much at all due to my new Classic Audio Loudspekers T1.5, which is in another post. 
Anyway, here are some views of my smoothing progress as measured at the center of the room, which is the new listening position with my giant speakers. You can see the initial response and after response. Playing with different frequencies, phase, etc., and given time, you will get a smoother plot.
https://www.amazon.com/photos/shared/rP9gxID-Ts6SZNr4AwftqA.NFFn8vgXexCg9g-SaViCMW

 But, and I say this, do you really want a smooth bass plot? It’s sort of a rhetorical question, but if you want excited bass at let’s say, 50hz, you may want to visualize what it will sound like for you, in your room, with your equipment. I think smooth bass is okay for critical listening if your speakers need it, but not all speakers need extra bass. But yes, if they do, then add subs to help augment that portion of the musical spectrum that your speakers can’t reproduce. 
I find myself using subs less now that I have speakers with 18” downward firing bass, and 15” front firing bass. 
The room is a major component of your audio system. If you can, spend money on room infrastructure things such as sound insulation (Roxul safe and sound) in the walls, Quietrock sheet rock, anything that will assist with noise abatement that will inhibit noise and bass from leaving The room will greatly benefit your listening pleasure and bring peace to your family who do not want to listen to Aerosmith at 100db with a 50hz bass bump to feel the kick of the drum. I spot treated with absorbers, diffusion as needed after I listened and measured the room to suit my needs. Good luck on your journey. 

@Smodtactical, I suggest you purchase a Minidsp. You have already invested a significant amount in your system. The Non-Hd version of the Minidsp is $100. The HD version of the Minidsp is even better and can do more.  

It  appears you are using REW and that is a good thing. REW will generate equalization filters specifically for the Minidsp. You then load them into the system via computer. There are videos on the web to guide you through the process.   

There is a learning curve to all of this. You are getting many suggestions all with good intentions. The bottom line is you have to experiment and learn as you go. Don't give up, and have fun on the journey.           

Yeah, I saw the recycled denim stuff, but it didn’t appeal to me. It just didn’t look rigid enough for what I wanted.
Actually, I glued, then used a brad nailer to secure the frame. Using glue and finishing nails would work if you don’t have a compressor.
Don’t overlook the Cambric material and 3M adhesive spray. It makes a difference. You’ll save money by not having to cover the back of the panels with Guildford of Maine cloth. I wrapped the entire batt with it (cambric material).
You could see if Home depot will cut to size and deliver, but you need to order the right wood. If you go there yourself, you can pick the best pieces (straightest, and less knots). They’ll cut it for you there as well.
Something like this for the walls or ceiling (lumber edges are rounded and smooth):
https://www.homedepot.ca/product/thd-generic-1x2x8-framing-lumber/1000173739
For 3" for Bass traps you could use this:
https://www.homedepot.ca/product/thd-generic-1x4x8-millstead-spf-sdry/1000100188
You’ll probably want some D-rings for hanging them. Each panel will weigh almost 10 lbs (over 20 lbs for Bass traps), so I used these - https://www.homedepot.ca/product/ook-large-2-hole-d-ring-hangers-value-pack-10pcs/1001027224

OP,

OK, I see the confusion. When I do an image search I get a lot of the Be series of Yamaha’s show up as NS 5000 speakers.

If this is the new, Zylon speaker, then the FR does not make sense to me at all.


Best,
E

@golfnutz Ya I think making them myself makes sense, can save a ton of cash. I wonder if I can order the wood pieces cut to precise size via home depot and have them delivered or something with the rockwool. And just order the fabric as you said, awesome plan. So then I just nail everything together and staple?
Just curious I heard some people using this special denim material that is a bit safer? Any thoughts on that?

@erik_squires Appreciate it man but ya I think NS5K is a totally different speaker.

He has NS5000... not NS1000... how did you make that mistake?

Enthusiastically!

Refunds are in the mail.

Still, the basic FR issues appear shared. 

AHA !!!

If these are the original NS 5000 I strongly suggest you get Troel’s crossover upgrades:

Everything I was complaining about in your measurements (except for the choppy HF) is fixed here.


http://www.troelsgravesen.dk/Yamaha-NS1000.htm


Otherwise, DSP is a necessary option. If you don’t want to do the EQ yourself, Anthem makes a pre and integrated that will do it for you and integrate your sub.



Best,

E

He has NS5000... not NS1000... how did you make that mistake?

If you're thinking about Acoustic Panels, you should consider making them yourself. The Rockwool Comfortboard 80 from Home Depot is as good as anything out there and it's only $58 for 6 pieces. It's very rigid, so you don't need to treat it at all. Check out the Acoustical Performance here -  https://www.rockwool.com/products/comfortboard-80/?selectedCat=comfortboard%E2%84%A2%2080%20downloads#Specifications&Sizes
For Bass Traps, just double up with 2 pieces for 3".
All you need to do is build a wooded frame, add the Comfortboard 80, and staple some Guildford of Maine FR701 cloth on it (about 5yds), which you can order from Duvaltex in Quebec. I added Cambric dust collection fabric to keep any loose particles intact, which is very cheap to buy (use 3M 77 spray adhesive to glue it on over the Comfortboard 80). Anything you buy won't be better than making your own.

AHA !!!

If these are the original NS 5000 I strongly suggest you get Troel's crossover upgrades:

Everything I was complaining about in your measurements (except for the choppy HF) is fixed here.


http://www.troelsgravesen.dk/Yamaha-NS1000.htm


Otherwise, DSP is a necessary option.  If you don't want to do the EQ yourself, Anthem makes a pre and integrated that will do it for you and integrate your sub.



Best,

E

Thanks guys. Will look into treatment and DSP.
I do plan to move to a bigger space in 2-3 years so thats why I have the NS5000. But I agree totally a smaller speaker might be better. Although not sure it would be better for bass impact?

+1 dznutz
...or as I suggested apply professional digital correction.

The best success I have had is using the Vandersteen speaker placement calculations for the main speakers.  This is available on their website.  I have two subs.  I have 11 acoustic panels, diffusers and traps.  I can walk around my room and the music sounds good.  It was not that way at all previously.  Several peaks and nulls. Good luck. 

Clearly you have not chosen the right speakers for your room.  The NS5000 are WAY too big.  Adding subs to that room is insane.

Best solution... get a bigger room.

Second best... get rid of those subs and speakers and choose the right monitors for your room.

That is so fascinating using all different kinds of subwoofers. Is there any downsides to this? Do they have different speed or timbre? 

Speed or timbre. With a sub. Good one. Guess you missed the part above where I said:

human beings cannot even hear low bass at all, at less than a full wave.

So for proof, my first sub was a ported isobaric Talon Roc. Isobaric is two drivers mounted back to back so one removes the air pressure from the back of the other one helping it move faster. Because the Talon Khorus uses the same isobaric design and so of course the bass has to be "fast" to match. This is the way they think. 

This way of thinking is baloney. My DBA with sealed and ported, and none of the drivers as massively powerful as the one in the Roc, is way better. It sounds faster, more tuneful and articulate, in spite of what looks on paper as if it would have to be much worse.  

You have to get out of the trap of thinking of low bass the way we think of midrange and treble. They are both waves and the physics is the same but the way we hear them is quite a bit different. 

Like, midrange we can pinpoint the source in 3D space. Low bass we cannot localize at all. Treble and midrange we can hear a millisecond blip. Low bass we cannot hear less than a full wave. At all. That's like 50ms. Midrange we are very sensitive to volume and hear volume changes accurately. Low bass we hardly hear at all until it gets quite loud (hence the Loudness switch), and then once it does we are overly sensitive to volume.  

What all this adds up to is with midrange and up we need two and only two perfectly matched speakers placed precisely symmetrical to create a 3D soundstage- but we can use a whole bunch of subs of all kinds and put them just about anywhere and yet they will integrate perfectly into that 3D sound stage.

These are the ns 5000? Excellent choice. I really appreciate what Eric is suggesting. I have a 6’x8’ piece of carpet hanging on the sidewall of my listening room, it helps. One day I may replace it with vicoustics or another brand, but it showed me how important taming that 1st reflection point is. 

Yes! It might make a difference between a standing wave or none- at your listening position.

@atmasphere  Does subwoofer direction make a difference since the waves are omnidirectional below a certain frequency?

Right now they are about 10 inches off the wall and they probably need to be moved out more.

@smodtactical  If your bass is rolled off, you're usually better off moving the speaker closer to the wall behind it. This is particularly true in the case of a sub- as it gets closer to the wall, the boundary effects start to come into play. So the bass goes up not down. But standing waves will also be more pronounced, so you should try the sub pointed in different directions, with different phase and in different locations along the wall if you can. The right spot might only be a few inches wide so if you're playing with a single sub this requires patience!

That is so fascinating using all different kinds of subwoofers. Is there any downsides to this? Do they have different speed or timbre?

Absolutely. Notice my system https://systems.audiogon.com/systems/8367 There's a 12" isobaric Talon Roc sub in the front left corner, two sealed 10" subs towards the front on the left and right, and two 10" ported subs in the back along the L and R walls. Each sub is near the wall but they are all different distances from the corners.  

The response of each of these subs is different, and the locations are different, and they even are adjusted somewhat differently. The Talon is powered and so its independent. The left two are on one Dayton amp, the right two on another. Left and right are close but not identical in level. Or phase. All this asymmetry would be a nightmare for the mains, but is actually what you want with subs. All the slightly different responses produce different modes, in different places, and at different levels.  

Placement becomes a whole lot easier with more subs. With just one you have one or two nasty humps to figure out. With four each one plays at a lot lower level so the humps are much smaller, and you can put them just about anywhere you want. I tried a lot of different things because it mattered so much with just the one. But with five I find it hardly matters at all.  

Hook em all up, you will see. 

Thanks guys for the great thoughts.
Erik, sounds like a good plan.
Miller, should I still use my 18s with the 10s? Like 2 18s and 2 10s?
Strojo: Via RCA from preamp to subs.

Your room is absolutly unique regarding the positioning and integration of a subwoofer/s. Other people's dimensions and locations, even if they're identical or similar, will require a great deal of trial and mostly error.

If you locate a sub at the listening position by using long enough interconnects (Monoprice or Bluejeans Cable) and an extension power cord while playing low frequency tone/s will allow you to walk (or crawl) around your room and map out YOUR rooms modes and nulls. This test tone download should be useful https://realtraps.com/test-cd.htm

This method is simple and need only be done one time. Once you've mapped YOUR room you can experiment by placing your sub/s at or very near the mode (louder bass) areas.

I found multiple subwoofers evened out my rooms modes. Controlling the subwoofers frequency response is a product of equalization and room treatment (Eric's blog). No amount of subwoofers can control frequency. While using four large subs I found equalization absolutly made such a desirable improvement I found two small subs to be sufficient. Then again, along with personal taste every room is unique. 
This is well worth the effort good luck with it. 

Hi OP,

Here's my blog on how well a 2-way can function in a small room, with room treatment.

https://speakermakersjourney.blogspot.com/2020/01/the-snr-1-room-response-and-roon.html

Best,

E

How are you all connecting multiple subs to your electronics?

It would be great though if I could solve this without subs. I wonder if bass traps would allow me to turn my subs up more while still retaining cleaner bass.

So here's how that works. In order to get even bass the conventional way you have to turn the subs up loud enough to bring the drop-offs up to where they sound good. This means having way too much energy at other frequencies. So you try and damp that out with traps.  

But the traps and loud spots are only in certain places, while the excess energy is everywhere in the room. This physical energy excites the walls, the whole room, and physically dissipates over time. Its the dissipation of this energy that smears and muddies bass response. There really is nothing you can do about it. More and more traps leads to more and more EQ and you just never get enough. 

What's funny is everyone knows the last thing you want is to have an overdamped room. A certain amount of acoustic reverb is nice and helps create a sense of spaciousness. Too dead and the room sounds... dead. Yet that is exactly what a lot of these bass trap people are having you do, only with bass instead of midrange and treble. So you don't notice it when you walk in the room the way you would with panels all over the walls that kill the sound. But its the same thing, only lower in frequency. 

You don't need 12" or 14" subs. Those are for when you haven't figured out the answer is more subs and still think its more sub. That "s" makes all the difference in the world. You can easily use 10" subs. I have four of em. Its not how big. Its how many. And where. Dispersed asymmetrically around the room. 

This will cost less, take up less space, and work better than all other options. I really cannot think of a single objection, other than the mental effort required of any new idea.

Hi OP:

Use the tools you have. Move the speakers back to see if you can find a better bass balance. Next, see the tooth like ridges in the high frequency? That’s evidence of regular reflections, possibly even slap echoes.

Yes, diffusion is a great idea, but at $400, I suggest you call GIK Acoustics and see what they could do in your budget. I mean, I am sure these are find diffusors, but for maybe a little more you might be able to get a lot more room treatment from GIK. They have an online service where you can send them pictures and room measurements. I strongly suggest you take advantage of it.

So, this is the order I recommend you work:

1. Main speaker placement
2. Room treatment
3. EQ
4. Subwoofer

For 3, the Schiit Loki ($149) may be just perfect. Only after you have sorted this out should you spend too much time attempting to integrate your sub.  I can't tell you how much more important 2 is going to be though. 

Again, what speakers are you using though?  This may provide clues.

Best,

E

@millercarbon: Ya I am not against a bass array. I would have to get probably 2 more subs and they would have to be smaller, maybe 12s or 14s because I am really running out of space. It would be great though if I could solve this without subs. I wonder if bass traps would allow me to turn my subs up more while still retaining cleaner bass.
@erik_squires : Ya moving the speakers around, forward, back, side to side seems something worth while and free! You mentioned dispersion, do you think dispersion panels behind the speakers would do anything  or be of any value ? My friend is selling two really nice 2 foot x 3 foot wood panels that look extremely well made for $400 usd for the pair.

OP:
We haven’t discussed your main speakers. What are they and where are they? It is possible they need more rear wall reinforcement. You also, 100% need mid-high frequency damping and dispersion.

If the former is true, moving the speakers towards the rear wall should help reduce the bass-mid imbalance. That is, you should get more bass out of these speakers.

Some one else mentioned Roon. Yes, if you have access to DSP and the other suggestions are not available to try first, this can help, but convolution filters are WAY overboard here. Simple parametric filters will fix everything you have, and not overtax your server.

However, room acoustics are the first place to go. You can’t fix your mid-HF hash with an EQ.

Also, the sub response honestly looks really good.  I was expecting to see a lot more garbage.  This is why I am suggesting that for now, you ignore it, and fix the mains.  That's where your problems are, and there's nothing you can do in the sub to fix this. 

You can play with them till the end of time, no amount of moving them around will have the least effect on the underlying physics. Been there. Done that. Found a better way. Don't do that no mo.

Probably I need to keep playing with speaker positioning as you guys are saying. I'll try to keep moving them around. Right now they are 28 inches off the front wall with 10 degree toe in.

Good thing you are measuring your room/system. Terrible curves unfortunately. I would skip the subs or cross them at 30-40 Hz and use the Roon digital equalisation. Preferably using convolution filters. You seem to have a "loaded" room so I don't think acoustical treatment will give you much help.

I had a similar issue.. Solved.. Do you have 3 way tower speakers ? if so, try this.. I first found the perfect toe in.. Then I placed 3/4 in rubber pads underneath the front of my speakers to tilt it back some..  Improved my bass a lot.. Sounds crazy, maybe ? It works for me..  Note that my bass driver sits towards the bottom of the tower.. Good luck.. hope you find a solution

BTW, the one thing I don't see evidence for is the need of bass traps.

I know the world will be shocked, but this is not the case here.  What you need is the slope from 1kHz to 10kHz to go further down.  The problem is not, as often the case, that you have too many room modes.  The problem is the relative output from 100 Hz to 1 kHz is far too low relative to the rest, and that is making your system feel like there's way too little bass.

Fix that and you may not even want a sub. :)  As I wrote in my blog:

But wait, you are trying to fix a bass problem right? Well, what if the problem is not too little bass, but too much midrange or treble? A live room will sound much brighter. Reduce that and, like magic, the bass appears like a Spanish galleon emerging from the ocean at low tide.

Here is another comparison, this time with left sub, 2 subs and no subs and a bit more smoothing (1/12) to make this more clear.

Great pic.  Um, you definitely have complications.  There's an increasing trend from 60 Hz to 1 kHz.  This should be flat or descending.  Also, notice the regular ripple starting at around 6 kHz.  That indicates regular reflections in the mid-treble.

Essentially you have way too much mid bass to mid energy. If this is a highly reflective room that would explain it. Before adding the sub, fix up your mains and room.

Look closely at phase between mains and subs. If you don’t have the phase right, it cuts out a hole where they should overlap due to cancellation. This same issue plagued me for a while, and while phase may not be the total solution, it’s a strong cause of “where’s the bass?” I found the lowest bass was dependent on the placement more, while the frequencies near the x-over point were very sensitive to phase. 

What about running a DSP module just on the subs?  A friend did this with great success.

Here is another comparison, this time with left sub, 2 subs and no subs and a bit more smoothing (1/12) to make this more clear.
www.diabolicaldesign.net/smooth.jpg

Here I did a curve with just mains, no subs and bit more smoothing at 1/12.
http://www.diabolicaldesign.net/nosubs.jpg

@erik_squires Its in the picture above called Measurefix. The purple line is with no subs (legend on the top left). I also tried doing 1 or the other sub as well.

@millercarbon thanks man, I will play with it.
Oh and I forgot to measure the front wall to the front baffle (I was doing to the back of the speaker). My speakers are 28 inches away from the front wall.
I am gonna try to play with the toe, lateral movement and the forward and back movement until I get the low end fuller while retaining the rest of the range. And once I hear something good I'll measure and compare. I think you guys are right in saying placement is the key here.

Humor me.  Turn the sub off and send me a pic of your mains full-range.

I did play with the delay of the subs based on what Tom wrote at PSA where he said you should add about 1msec delay for every foot away the sub is from you. So I have 1 sub that is 3 feet away facing me and 1 sub in the back left corner that is 9 feet away so I did adjust that. Can't really tell if that made a big difference though.

Of course not. Because he's full of it. The one foot per millisecond is based on being approximately the speed of sound in air. One foot per millisecond.  

There's a couple times this matters. One is side wall reflections. Side wall reflections that arrive within about a 3 to 5 ms window of the direct sound have a very bad effect on imaging. That is why we want our speakers a good 3 feet away from walls. The other time is with movies. If the screen is several feet closer or farther away from you than the speakers then the people talking on screen will be out of synch. That's it. 

This rule of his is not applicable to subs for the simple reason human beings cannot even hear low bass at all, at less than a full wave. Since a 20Hz wave is 1/20th of a second that is 50ms before we even hear it. So when it comes to subwoofer bass you can forget about timing. Its simply not a factor.

Guys thanks for all the suggestions. I will try them and keep tweaking. I did play with the delay of the subs based on what Tom wrote at PSA where he said you should add about 1msec delay for every foot away the sub is from you. So I have 1 sub that is 3 feet away facing me and 1 sub in the back left corner that is 9 feet away so I did adjust that. Can't really tell if that made a big difference though. Maybe slightly better.
But I think Erik is right that the only true way to fix this is to move my speakers around and likely get them more off the front wall. Right now they are about 10 inches off the wall and they probably need to be moved out more.
Here is updated measurements and I zoomed the axis so you can better see the contours.
@audiorusty, interesting idea about the variable crossover points on the subs. That seems cool. The acoustic fields guy also recommended subs at different heights to make things smoother.

www.diabolicaldesign.net/measurefix.jpg

OP:
In general, your measurements show the two are not integrated. You want the bottom and upper part of this graph to merge completely seamlessly.

I only have a delay knob on my subs (PSA V1800). Is that what I should play with? I don't have polarity or phase controls.

My suggestion:

1. Minimize the phase setting.
2. Flip the wiring to the main speakers to compare.
3. Pick whichever wiring gives better response.
4. Adjust the phase dial from that point to eliminate null.
   
5. Adjust sub level to elimiate step between sub and mains.