Bass - how much is too much?

To answer a few more questions - firing speakers down room- I tried many variations but none were as effective as firing across the room. Domestic acceptance may also be an issue with speakers well out from the boundaries. There was also a notable mid frequency ringing which really colored the sound - not good. 

The fcxs = out B to upgrade 1 and out A to upgrade 2 - I was surprised by the improvement here. 

In Answer to your question Huge I would consider spending up to £1k on room treatments as long as it continues to look like a lounge and not a studio. It does seem like a complicated process but I haven't really spent any time yet reading up on the technical side of things. If placement of absorption panels is critical to get any sort of results then it may be tricky.

One idea I had was to build a corner cupboard in one or two of the free corners and use bass trap/ absorption panels as doors. The cupboards could hold my Cd collection and other stuff??  Not sure if this would be effective. The worst corner is a bit more tricky as there is a full height window. There is 2 feet of free wall space next to this which could accommodate a panel. In front of the window I could place a chair with a floor bass trap underneath. I have no idea if these ideas are worthwhile or simply ridiculous. It would be good to improve room acoustics to some degree (maybe not perfect) but this would make it easier for future upgrades. 

I am not familiar with Linn gear but will take a look. Hope this gives food for thought. Will post a few pics later. 

Before

After

Rest of the room

The far corner with window which seems to be the problem area

Do you sit between the speakers or offset to the side on the sofa (it looks from the photo that a door is in the centre) ?

You left speaker: sound waves reverberate off a soft sofa and a wall, which is further away, and get trapped in a corner behind a sofa and bounce to the left with a lot of empty space.
Right speaker: sound waves reverberate off either a closed glass door or a hallway....

I think with a setup like this it will be difficult to achieve satisfactory results - uneven reverberations will always spoil whatever effect you'd manage.

Example: Low frequencies form the left speaker get absorbed by a sofa, the right ones have a lot of empty space or they bounce off a closed door....

I have a shed load of observations, but I'll have to wait till this evening before I have time to detail them fully.

Watch this space ' ' (it won't do anything but you can watch it if you like. )

Have you tried the furniture / speakers as above? If you could live with a speaker in front of the tall window it might work. I would suggest then try moving speaker 1 slightly out from the wall.

Max_B posted:

stuart posted:

There is one small fly in the ointment. I have been listening particularly for the upper frequencies and focusing my attention to that. HH drew my attention to the problems he had with untamed bass with his original motive 1s. I now can't stop listening to the bass frequencies!! 

Stuart 

Wouldn't it be better if you stopped listening to HH?

;-)

That advice certainly worked for Hilary....

The problem seems simple to me: rather than thinking of £1,000 to make the speakers work, just don't buy the speakers. A 155 is never going to control Motive 1s. 

A Supernait 2 and some ATC 11s might be a way forward.  

Hungryhalibut posted:

The problem seems simple to me: rather than thinking of £1,000 to make the speakers work, just don't buy the speakers. A 155 is never going to control Motive 1s. 

A Supernait 2 and some ATC 11s might be a way forward.  

He's got a point. I found my old Motive 2's boomed when we moved house so they went and never got on with the Motive 1 (too much bass in the dealers dem room). Worth trying a better amp with your present Motive 2's if you like what they do. 

Sn2 and scm11 would make fine bedfellows and a good match for your room size.

ATC SCM11 - yes, now you're talking!

The red areas are likely to be the highest levels for bass below 60Hz, you can see corners are the worst, especially if the walls are brick, and it's these areas that would be best avoided for listening and speaker positioning. My own view is that there is nothing you can to do to reduce low bass in these areas unless you treat the room with lots of mega bass trapping in these areas. This will be very expensive (there are limited products on the market that will work) and it will spoil the look of a room. Moving speakers and listening position more into room helps a lot but may not be practical and you may end up too close to speakers. The only other options are eq (will incur some loss of sound quality) or downgrade speakers to reduce bass energy. It's nearly always best to fire down the longest length of the room if this is possible. High and mid frequencies (first reflection points and behind listening position) can easily be treated by replacing your existing wall art with acoustic art panels and using heavy duty lined curtains on glazed areas. You will also benefit from broadband bass traps such as Gik tri traps in corners behind speakers but these wont be very effective below 60Hz.

Observations...

The room asymmetry won't affect the bass too much, it may affect the mid and HF.
Fixing the asymmetry:  This is the easy one...  put a large heavy chair between the radiator and the door.

You're going to get very prominent room modes at 34.9Hz, 46.5Hz and a lesser one at 55.8Hz when the door is closed.  With speakers whose bass extension is below 65Hz, these will cause major bass problems (peaks in the base response that could easily exceed +20dB, and also cause long decay times at these frequencies.  If you place the speakers out from the wall you'll be able to use speakers with a bass extension down to about 55Hz.
To fix this with the speakers you have will require considerable investment in bass traps.

The position of the door can affect the mid bass and/or the midrange frequency response, it may also affect the imaging and presentation of vocals and instrumental timbres.

The room may be very bright with long decay times at some frequencies particularly the specific bass frequencies noted and also from the upper mid to HF regions (leather is surprisingly reflective of HF energy).  This can cause boom in the bass region, 'spittyness', brightness or HF harshness, strange stereo imaging artefacts and also some 'odd' effects in vocal presentation.

Of course, no room is perfect and it's a question of striking the right balance and what works for you.

I'd put SCM11s on the right hand wall, either side of the window

jon honeyball posted:

I'd put SCM11s on the right hand wall, either side of the window

I'd agree with the ATC SCM11, and agree with starting with them by the window, but I'd also try them where the current speakers are, to see which arrangement is better.  The SCM11s will be happier close to a wall than the Neats are (note that they'll still be better with some distance behind them, but if you can't give them that, the the effect will be much less detrimental than it is with the Neats.

Note that there are also some other small speakers that will work well (and some that won't), but few of these have as good an overall performance as good as the ATC SCM7 and ATC SCM11, unless you spend a lot of dosh (Wilson Bensch Duette anyone? - N.B. I'm not suggesting them - way to expensive and way too tough a load for you other equipment!).

Thanks again for all your help and comments. I have had some success with moving the left speaker and replacing foam bungs in the ports. The front of the speakers are 22 inches from the back wall. For the most part as long as the volume is sensible they sound fantastic particularly on well recorded tracks - no hint of boom or overhang. 

Firing across the room is definitely the best presentation - tried all manner of positioning firing down and didn't like the results 

I can't really rearrange the furniture without causing a tad of domestic disharmony which I would rather avoid although some degree of aesthetic acoustic panelling would be OK.

To my ears it feels like it doesn't require too much more to improve things but I have no idea how much in the way of bass trapping would be required. I accept that it won't be perfect but a 30-50% improvement would be great 

TBH the upper and mid range sound open and well balanced with not too much colouration. 

I think I will probably try more options before I commit to these. My dealer stocks pmc, proac, sonus faber and focal. I do like the suggestion of atc but don't have a local dealer. 

I very strongly recommend getting a copy of REW (shareware) and a miniDSP UMIK-1 microphone and actually testing the acoustics of your room.  Doing this may save a lot of regrets later when you become accustomed to the sound of speakers and start to find 'odd' features that you missed at first.

This will also show exactly what the room is doing, as ears aren't the best choice for estimating sound below about 200Hz.

[@mention:2833539978796882]

An idea to help you with identifying booming spots in your room: I noticed you have some guitars around.  
Do you have a bass-guitar playing friend who has a good bass-combo?
Get him over into your lounge and get him to play all the notes in a chromatic scale of E, starting with open E, and progress through two octaves.
Experiment with placing the amp in various locations (starting with where you have your speakers).

You will quickly realise where problem areas are and at what frequencies you get dull / out of control bass.

An altenative is to use the measurement tools Huge has recommended.

You've had some really useful suggestions from others and I just wanted to add my experience with booming bass in a similarly sized and shaped room. I had floor standing speakers with downward firing bass ports and like you was very happy with them most of the time. However, certain bass frequencies boomed wherever I positioned the speakers and over time it annoyed me more and more. In the end I changed to ATC SCM 19 speakers. This solved all the problems (plus incidentally gave me a much better mid range!). No, I don't have the very lowest bass frequencies but I do have very tight tuneful bass which sounds much better.  My point is NOT that you should buy the same speakers but just to reassure that it is possible to solve the issue and that it could be worth experimenting with different models. 

To test with biko/peter Gabriel 

Based on dimensions of 4.8 x 3.3 x 2.3 m here are some of the bass notes that can form stationary waves in the box (calculated by amroc dot andymel dot eu) and the corresponding modes of the box. The lower frequencies are fundamental ones and if I recall the method of calculating by hand they are half wave length and the higher frequencies are multiples of the fundamental. I don't see how the low frequency waves  could have high amplitudes near the walls in a room of this size. Therefore if there is boominess I would suspect the electronics and speakers more than the room.

I have a larger carpeted room and don't suffer from bass boominess problems. I form a equilateral triangle - my speakers are toed in a lot. I sit outside and off centre. With Sopra N2 rather than the Spendors A6Rs I previously had in the lounge I don't notice any spots where the sound is louder. Most places in the room are enjoyable.

As Naim are more renowned for PRAT than a soundstage it doesn't seem worth trying to reduce the toe to improve the soundstage as some suggest. As long as I enjoy listening to the music, soundstage seems less important. 

Mode Table:

1 35.73 Hz D1 1-0-0 ax
2 51.97 Hz G1# 0-1-0 ax
3 63.07 Hz B1 1-1-0 tan
4 71.46 Hz D2 2-0-0 ax
5 74.57 Hz D2 0-0-1 ax
6 82.68 Hz E2 1-0-1 tan
7 88.36 Hz F2 2-1-0 tan
8 90.89 Hz F2# 0-1-1 tan
9 97.66 Hz G2 1-1-1 obl
10 103.28 Hz G2# 2-0-1 tan
11 103.94 Hz G2# 0-2-0 ax
12 107.19 Hz A2 3-0-0 ax
13 109.91 Hz A2 1-2-0 tan
14 115.62 Hz A2# 2-1-1 obl
15 119.12 Hz A2# 3-1-0 tan
16 126.13 Hz B2 2-2-0 tan
17 127.92 Hz C3 0-2-1 tan
18 130.57 Hz C3 3-0-1 tan
19 132.82 Hz C3 1-2-1 obl
20 140.53 Hz C3# 3-1-1 obl
21 142.92 Hz D3 4-0-0 ax
22 146.53 Hz D3 2-2-1 obl
23 149.13 Hz D3 0-0-2 ax
24 149.31 Hz D3 3-2-0 tan
25 152.07 Hz D3# 4-1-0 tan
26 153.35 Hz D3# 1-0-2 tan
27 155.91 Hz D3# 0-3-0 ax
28 157.93 Hz D3# 0-1-2 tan
29 159.95 Hz D3# 1-3-0 tan
30 161.2 Hz E3 4-0-1 tan
31 161.92 Hz E3 1-1-2 obl
32 165.37 Hz E3 2-0-2 tan
33 166.89 Hz E3 3-2-1 obl
34 169.37 Hz E3 4-1-1 obl
35 171.5 Hz F3 2-3-0 tan
36 172.82 Hz F3 0-3-1 tan
37 173.34 Hz F3 2-1-2 obl
38 176.48 Hz F3 1-3-1 obl
39 176.72 Hz F3 4-2-0 tan
40 178.65 Hz F3 5-0-0 ax
41 181.78 Hz F3# 0-2-2 tan
42 183.65 Hz F3# 3-0-2 tan
43 185.26 Hz F3# 1-2-2 obl
44 186.05 Hz F3# 5-1-0 tan
45 187.01 Hz F3# 2-3-1 obl
46 189.2 Hz F3# 3-3-0 tan
47 190.87 Hz G3 3-1-2 obl
48 191.8 Hz G3 4-2-1 obl
49 193.58 Hz G3 5-0-1 tan
50 195.32 Hz G3 2-2-2 obl
51 200.44 Hz G3 5-1-1 obl
52 203.36 Hz G3# 3-3-1 obl
53 206.56 Hz G3# 4-0-2 tan
54 206.68 Hz G3# 5-2-0 tan
55 207.88 Hz G3# 0-4-0 ax
56 210.93 Hz G3# 1-4-0 tan
57 211.03 Hz G3# 3-2-2 obl
58 211.5 Hz G3# 4-3-0 tan
59 212.99 Hz G3# 4-1-2 obl
60 214.38 Hz A3 6-0-0 ax
61 215.75 Hz A3 0-3-2 tan
62 218.69 Hz A3 1-3-2 obl
63 219.72 Hz A3 5-2-1 obl
64 219.82 Hz A3 2-4-0 tan
65 220.58 Hz A3 6-1-0 tan
66 220.85 Hz A3 0-4-1 tan
67 223.7 Hz A3 0-0-3 ax
68 223.72 Hz A3 1-4-1 obl
69 224.26 Hz A3 4-3-1 obl
70 226.53 Hz A3# 1-0-3 tan
71 226.97 Hz A3# 6-0-1 tan
72 227.27 Hz A3# 2-3-2 obl
73 229.65 Hz A3# 0-1-3 tan
74 231.23 Hz A3# 4-2-2 obl
75 232.12 Hz A3# 2-4-1 obl
76 232.42 Hz A3# 1-1-3 obl
77 232.71 Hz A3# 5-0-2 tan
78 232.85 Hz A3# 6-1-1 obl
79 233.89 Hz A3# 3-4-0 tan
80 234.83 Hz A3# 2-0-3 tan
81 237.11 Hz A3# 5-3-0 tan
82 238.24 Hz A3# 6-2-0 tan
83 238.44 Hz A3# 5-1-2 obl
84 240.51 Hz B3 2-1-3 obl
85 240.91 Hz B3 3-3-2 obl
86 245.48 Hz B3 3-4-1 obl
87 246.66 Hz B3 0-2-3 tan
88 248.05 Hz B3 3-0-3 tan
89 248.56 Hz B3 5-3-1 obl
90 249.24 Hz B3 1-2-3 obl
91 249.64 Hz B3 6-2-1 obl

Filipe,

The pressure levels of the standing waves will be greatest neat the walls, the particle velocity of those same waves will be greatest in the centre of the room.  This is the normal interplay between potential energy (as pressure) and kinetic energy (as particle movement) that constitutes a longitudinal standing wave.