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bass boom

Mr_Sukebe said:
I have GIK bass traps. They do NOT stop bass nodes in a room.
DEQ is my solution.

The only other really viable options are a different room, or speakers that don’t go low enough to set off the peak node.
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Nothing stops bass modes, the best you can hope to achieve is to ameliorate them to the point that you can live with them. I've managed to control my bass modes down to frequencies of 50Hz to a satisfactory level with room treatment alone. My 40Hz axial length bass mode is still problematic and I'm told would require treating the entire front and rear wall with 40cm deep absorption. I'm not in a position to do this, but if I was then I would, because at the moment I am confined to sitting in the middle 20% of my room. If I move forward or backward any more than this, the 40Hz boom becomes intrusive and gives me a headache. Not a problem most of the time because I have the sweet spot all to myself but when I (occasionally!) have guests I need to sit 3 feet behind the sweet spot and it isn't a pleasant experience! I could, of course, EQ the 40Hz mode to make it more tolerable in the 'back row' but that would be at the expense of my guests sat in the 'front row'!
 
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mandryka said:
I once put my JR149 Mk1s about 30cm from the floor (wood, not floating) and the result was boomy bass. I posted about it here, I can't find the discussion, but someone said (quite rightly) that the problem was the height - the floor was doing something to the low frequencies and that made the experience boomy. Defo worth raising them to see if that reduces boom, I mean it's easy to do! I'll search more thoroughly for the discussion later, as it's annoying me that I can't find it.
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Neil P said:
They are floor standers, but I can rest them on a chair each, to see what happens. The walls, I should add, are bare plaster at the mo, the only furniture is 2 sofas, and a flimsy bookshelf covering an archway into another room. It is possible the bookshelf back is wobbling along with the bass.
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If the boom is caused by your axial height mode then raising the speakers off the floor will reduce the boom, as will raising the height of your listening seat. An easy way to test this when listening to music is to stand up so that your ears are halfway between the floor and ceiling. If the boom diminishes then you know how to fix the problem!

If the boom is caused by your axial length mode then you will instead need to move the speakers and/or listening seat further away from the front and rear walls. Again, it's easy to test this. As you walk towards the centre point of the room, the boom will diminish, and as you continue beyond the centre point and get closer to the front wall the boom will get louder again.
 
Neil P said:
Has anyone found that dense wooden floor on foil/foam underlay can affect sound? I mean everything affects sound, but I wonder if the entire floor (floating on its underlay) can some how wobble in time to deep bass?
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Or can hollow sofas etc boom along? The arms of my sofa are 5 sided chipboard boxes ...
 
I've also found that speaker cables can affect the balance of bass in the overall sound mix with some over emphasising bass. Whilst a change of speaker cable won't affect the room resonance nodes it may reduce the amount of resonance created in the first place such that most music becomes much more listenable. Tuning your system through appropriate cables use is a topic of its own but if you have a friend who can lend you a different make of speaker cables it might be worth a try to explore the affect in your system...and it's 'free'.
 
les24preludes said:
It may well be the room, but don't completely dismiss amp-speaker interaction, especially with SE tube amps and ported speakers.
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Standing waves, room modes and listening space acoustics notwithstanding, DEFINITELY consider speaker-amp incompatibility. Whether we like it or not, this most definitely exists as a genuine possibility. Don't ask me how I know!
 
whsturm said:
I've also found that speaker cables can affect the balance of bass in the overall sound mix with some over emphasising bass. Whilst a change of speaker cable won't affect the room resonance nodes it may reduce the amount of resonance created in the first place such that most music becomes much more listenable. Tuning your system through appropriate cables use is a topic of its own but if you have a friend who can lend you a different make of speaker cables it might be worth a try to explore the affect in your system...and it's 'free'.
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No cable in the world will solve the bass that drastic. Period.
 
Neil P said:
I'll soon be packing up the system ready for refurb, so won't be going down the REW / mic / room treatment route any time soon. However, are there any likely ways to reduce bass boom in a room? Floor coverings? Book shelves in corners? hanging pictures on bare walls? It's a family room so can't be covered in GIK panels.

The floor is wooden ... possibly suspended, will lift up a floor board in the coming weeks.

Diagrams and detail to follow.
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While it is better to test the room using REW and a mic, you can simulate your room using REW room simulation. It allows you to locate your speakers and listening position in a room of your dimensions it shows you what the bass issues are and how they change as you change your listening position. In my room I found the listening position made the greatest change.

All of the room dimensions cause resonances, the ceiling hieght gives rise to my troublesome bass resonance, i can reduce this by changing my listening position but I chose to use Parametric EQ guided by the results from REW.

Try the room simulator, find out what it comes up with, I found it a revelation And it’s free to try.
 
If you have room modes that are a problem then you can use Helmholtz resonators to reduce the effect of them. An acoustician tuned my room using 1.5 m long and 10 cm diameter tubes with movable bungs to be effective at required frequencies. They are effective at reducing room modes with resonant frequencies between 50 to 150 Hz. Longer tubes can be used to reduce lower frequencies but it becomes increasing difficult as the frequency reduces. At that point sub woofers operating in anti phase could work, but I have never needed or tried the approach.

More tube can be used to reduce the effect of the room mode further, in each case through using the original signal to create a cancelling anti phase at the frequency set by the length of the tube.

My room had resonant modes between 60 and 100 Hz, with a large void below my wooden suspended floor to make the problems worse. I was able to hide some of the tubes under the sofa and behind the curtains, but the problems were larger than seen in an average room and so required more tubes than usual, which are mostly hidden behind the sofa.

I used the following company:

blackseaaudio.weebly.com

Black sea audio acoustic designs

Black sea audio - Acoustic design solutions. Acoustic designs providing the perfect acoustic for every space.
blackseaaudio.weebly.com

Karl, who runs the company, has tuned an enormous number of rooms, including Cadogan Hall in London, and the auditorium at the company I used to work at, using Helmholtz resonators amongst other approaches.
 
Neil P said:
I'll soon be packing up the system ready for refurb, so won't be going down the REW / mic / room treatment route any time soon. However, are there any likely ways to reduce bass boom in a room? Floor coverings? Book shelves in corners? hanging pictures on bare walls? It's a family room so can't be covered in GIK panels.

The floor is wooden ... possibly suspended, will lift up a floor board in the coming weeks.

Diagrams and detail to follow.
Click to expand...
Boomy bass is normally the result of one or both of two things. You might be experiencing peaks in the low frequency response at the listening position caused by modal resonances. Alternatively or perhaps additionally, your speakers might be too close to wall front wall or corners of the room.

None of the options you have covered will have much impact on low frequencies. You could try rearranging your speakers and sofa. You could install bass traps, but you will need a lot of them to make a meaningful difference below about 75Hz. Or you could use an audio processor to apply some EQ.

Audio Processors Archives

Audio processors manipulate the audio signal using digital signal processing technology, for a variety of different purposes.
strictlystereo.com strictlystereo.com
 
One key thing I’ve learned is that not all speakers behave anything like the same way in the same rooms. Some boom like crazy, others are absolutely fine with no change to the room. The real problems for me have always been ported stand-mounts where the port frequency is around the primary room node (typically between 40 and 50Hz in a typical UK living room). Larger speakers without aggressive port-loading just don’t seem to excite the room at all. Smaller infinite baffle types don’t either, but the ones I’ve tried here are a bit small for the space.

The worst performance I’ve had here by far was a pair of Musik Eletronik Geithain RL904, which are a truly amazing pro-studio active monitor speaker. Some of the best speakers I’ve ever owned for sure, but they hit the room node to a ridiculous and unusable extent. It would take all manner of digital chicanery to notch out (which I am simply not prepared to use in a purist analogue system). Swap the huge Tannoys back in and no boom at all. ProAc Tablette Ref 8s boomed here too, and they are another nice speaker.

It is certainly worth trying a few alternatives before assuming the room is as bad as you think.
 
If you can't move the speakers, forget it. The precise way in which the speakers interact with the walls of the room is the primary cause of bass boom and moving the speakers is the best way to fix it. Nothing else is going to work as well.

I just read a couple of reviews and your speakers are well liked but criticized for 'one note' and loose bass at times? Not going to help. You could try smaller speakers with tighter, less deep bass?
 
Mr Pig said:
If you can't move the speakers, forget it. The precise way in which the speakers interact with the walls of the room is the primary cause of bass boom and moving the speakers is the best way to fix it. Nothing else is going to work as well.

I just read a couple of reviews and your speakers are well liked but criticized for 'one note' and loose bass at times? Not going to help. You could try smaller speakers with tighter, less deep bass?
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Ok - please can you link to the review. Thanks
 
ToTo Man said:
In that case the only option you're left with IME is using EQ to cut the frequency that's causing the boom, because if the boom is unacceptably loud and you are not allowed to ameliorate it by moving speaker and/or listening position, then you'd need to spend a fortune on - and give up a huge amount of space to - room treatment that, when installed, will have a similar effect to moving your listening seat a couple of feet further away from the wall. It would be helpful to know what frequencies are booming, as the higher the frequency, the easier it is to treat.
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My room has a problem with bass but only at a certain voulme level, very quiet is fine, especially as the Yamaha is extremely good at low volumes. At a decent level I get some bass boom but very loud it goes away! 😂

I sit on a back wall so ideally move the sofa forward when I’m on my own before my better half comes home and wonders why the sofa's in the middle of the room! 😮😲🤔
 
Bass 'boom' is usually the result of your room nodes, these cannot realistically be treated with treatment unless it's significant and intrusive and then you usually just dampen the energy across the low frequency and not just around the node. Some diaphragm based 'traps' can be effective (GIK do some). The problem with a room node is they are usually at difficult frequencies to treat and also have very long decay (RT60 times) so they effectively 'ring' at the low frequency. The way to solve or reduce effectively is

  1. Some bass trapping if the diaphragm and node are well matched might help
  2. Corner 'traps' might help, but invasive (there is nothing magic about the corner other than the absorption is increased due to local reflection)
  3. Move the speakers and toe a little, you may find small adjustments reduce the speaker exacerbating the node
  4. EQ the node and take some of the energy out, this usually reduces the RT60 times as well
  5. Move the seating position a little, just walk around and you will see where the node is worse.
You say you don't want to use REW but this will tell you a lot about the node and 'problem' and may highlight a solution

The only other solution is a speaker with less bass, which is no different than reducing volume, not a great idea if you want full range !
 
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