Changing My Room Acoustics

[reflux075]

Hi peeps,

 

I have recently changed speakers and after a few months of moving them around to try and get the best placement I have discovered something quite frustrating.

The bass gets cut off ONLY at my listening position. The moment I stand up from the couch, the bass is all there, sit back down and the bass is gone.

I have tried moving the speakers right back against the wall, I have tried moving the speakers reeeeally forward, and it does not help.

I know my setup is not ideal but I don't really have to much chance of rearranging the room, peace with SWMBO is much better than bass.

I'm thinking I need some sort of room treatment?

I have never done any of this before and would appreciate some suggestions as I do not know my bass traps from my reflectors.

Some pics of my listening area below.

 

 

[Snoopy8]

Given you cannot re-arrange the room because of WAF, I doubt you can do room treatment to address your bass null at the listening position.  Bass traps work best on corners and are large, but often not acceptable in a shared room. Alternately, adding a sub or two wth DSP can improve things.

 

Ideally, you should measure your room and understand it before taking the next steps. But you can also hire someone like @Red Spade Audio (who is Melbourne) to advise you on what can be done. 

[Satanica]

Measuring Euipment, Subwoofers, Integration, EQ, Positioning, Room Treatments. 

[Bunno77]

Had a similar situation recently where listening position was terrible but move a metre and all good. unfortunately the seating position couldn't change.

Speakers have been in a few houses and never a problem until this house.

Measuring, EQ, sub, placement, some absorption panels and nothing helped. Spun everything 90 degrees onto a different wall and it's back to being pretty much perfect. Can plonk speakers anywhere, sit anywhere and it is really nice.

The other issue is in your hands

[frednork]

If your description is correct then agree with those above that treatment is unlikely to help your bass deficiency at the listening position. I have listed some strategies which you can do yourself loosely in order of cost and difficulty.

 

If you can move things more than you have already then that may be worth trying first . One "hack" is to place the speaker at the listening position and play some music and stand in the various positions you have available for speakers to go and find the spots with the best bass and plonk the speakers there. Whilst not perfect its probably as good as it will get without moving to stage 2. 

Stage 2 is to get a sub and plonk it somewhere and see if it helps. A better way would be to do the same as above except with sub at listening position and try various possible spots for the sub. THeoretically it could be anywhere, front side back as long as the crossover freq is low enough. if that is not good enough move to stage 3

 

Stage 3 is to measure the room using a measuring microphone and software, determine what frequencies are missing from the listening position  and then set up a sub and remeasure and adjust sub settings and position until optimal. still not happy? time for stage4

 

Stage 4 would be to also use something like Multi sub optimiser software (oh yeah , need another sub) which will calculate the optimal settings for your subs  (oh yeah , need dsp as well), 

 

There are also commercial bass management units, I havent tried those but many here have, hopefully they will chip in on their usefullness for your situation.

 

Of course you could call in someone to measure and suggest for you

[reflux075]

Thanks for all the suggestions everyone! I will make my way through all of them. I was trying to avoid getting a sub, just sold mine actually haha. It might be the easiest option for me right now though. 

[Snoopy8]

There is another option.  Speak to Peter at DeepHz about one of these

http://www.deephzaudio.com/DSPeaker product index.html

The Anti-Mode 2.0 is used by a number of people here and may do the job.  If you have the budget, go for the Anti-Mode X4.   The DSPeaker products are easy to use.  Peter is in Melbourne and does offer home demos.

[Red Spade Audio]

Thanks for the mention Snoop!

 

It's likely the problem is with the listening position relative to room boundaries. Bass traps won't significantly improve the situation within practical limits.

 

Best options:

 

1. One or more subs in strategic locations to fill in the missing bass. Keeping in mind that subs can come in different shapes and sizes to fit the space.

 

Here is one example of that approach:

 

 

Black line in this example are very large mains with dual 12" woofers. The sub used here was tiny in comparison with a 10" driver. The right position (and a little EQ) here delivers what physics (and bad luck) prevents the much bigger mains from delivering.

 

2. "Nearfield" sub, placed right behind your listening chair.

 

Due to proximity, the room has less impact on the response of the sub, which tends to reduce those big dips. This solution might sound simple but I typically consider it a last resort when all else fails, because it can also tend to localise. In other words, you may actually hear bass coming from behind you, which is distracting when it happens. Many subs will not work in that position for this reason, so it's an option you'd want to trial before buying.

 

3. EQ to your mains.

 

If you have sufficient headroom, in some cases EQ added to your mains can resolve the issue well enough. In most cases, you simply won't have the headroom.

 

Some choose a "coffee table sub." This can work with with either approach 1 or 2. Here is an example of a coffee table sub that worked well:

 

 

Black = front corner sub

Red = same sub hidden under an existing coffee table to the right of the main couch

 

This was a home theatre room and using a coffee table sub to the side filled in the missing midbass region around 40 Hz. The bass in movies became dramatically more dynamic as a result.

 

Key point is that measurements show you very clearly what is happening and they also point to workable solutions for your specific room. It's also a very good idea to use them to integrate the solution chosen or validate the results of any correction system used.

[WasM]

If you stand up and the bass comes in 'full' could it be a consideration to sit the speakers on a solid plinth to hear how that changes the bass. This will very likely affect the upper frequencies and screw up the dispersion but could possibly 'tilt' the speakers back to aim 'down' to the seating area.

 

Maybe try 300mm lift?

[reflux075]

Thanks @Snoopy8 and @Red Spade Audio, I was hoping to avoid DSPs and EQs and Subs if possible. I guess I wanted to know if room treatment will help my issue but I guess it will not really help.

 

@WasM, you are the second person to suggest I try aiming the speakers down, I will try this but need to maybe change the front spike shoes as I don't have much to play with on the front spikes after leveling the speakers.

Also don't think I can raise it by 300mm, seems like quite a height increase!

 

I did try some extreme toe in suggested by someone and it did help the bass but I also got a splashiness with the top end on some songs that was not there before. Can't win haha.

[WasM]

2 hours ago, reflux075 said:

 Also don't think I can raise it by 300mm, seems like quite a height increase!

 

I did try some extreme toe in suggested by someone and it did help the bass but I also got a splashiness with the top end on some songs that was not there before. 

One can only try... and since it takes a small effort at no $ I would have a go. 

Grab some spare wood, bricks or anything suitably sturdy to elevate the speakers, then adjust toe in and angle.

[Primare Knob]

With bass problems, you have to move speakers and or listen position a lot to generate a difference.

Doing this by ear is difficult. As a bare minimum you could use a pink or white noise LF signal on both speakers at the same time and walk around the room and map the spots that show the most stable reading.

Room boundaries produce problems at 1/2, 1/4, 1/6 of the room dimensions and speakers needs to be placed in such a position to try and fix a problem, and seating positions need to be moved away from such dimensions.

Try and find out which arrangement gives you the least nulls/dips, as those can't really be EQ-ed. Peaks are easier to deal with using EQ.

Have you tried a non semitrical setup? As that can help dealing with near room boundaries that are speaker-wall related.

[Hipper]

As you've heard the general rule for getting bass right in a room is positioning, then room treatment. Positioning can also include using one or more subs and getting their position right.

 

This is the arrangement I use:

 

http://www.barrydiamentaudio.com/monitoring.htm

 

It's called 'The Thirds' but you could also do 'the Fifths' and the results should be similar. Try it as an experiment just to hear what it can do.

 

Room treatment for bass involves large boxes of the order of 40cm square sitting in two or four of the wall-wall corners.

 

None of the above seem practical for you.

 

One possibility is to move the speakers (and listening chair if possible) to their ideal location just for listening, and then store them out of the way when not in use. Place them on some sort of roller bearings (such as used for washing machines for example).

 

If you can't do any of this then DSP is the only other solution. The Anti-mode has been mentioned. There are also various forms of MiniDSP that could suit you. Whilst in principle you may not like DSP/EQ but any possible detrimental effects (I use a Behringer DEQ2496 and find no ill effects despite what others say!) will be far outweighed by a good DSP implementation.

[AudioGeek]

That is a lovely space you have there.

 

I am thinking you are gong about this the wrong way. Forget all the rest and get a system that was made to work in a typical multipurpose compromised home listening space like you have. Look at the Kii three or similar where you can place the speakers right against the back wall. You can get rid of amps etc and reduce the box count while getting better sound quality.

Room treatments, DSP etc are fantastic tools, but can be hit and miss unless you really know what you are doing and prepared to spend time measuring and testing. For a space like that they can also present aesthetic challenges.

[Snoopy8]

20 minutes ago, AudioGeek said:

Look at the Kii three or similar where you can place the speakers right against the back wall. You can get rid of amps etc and reduce the box count while getting better sound quality.

Agree Kii would reduce box count but not sure putting it in back wall will work?  It is still a speaker and placement is still important to get the best sound.

[reflux075]

8 hours ago, AudioGeek said:

That is a lovely space you have there.

Thanks for the nice compliment @AudioGeek

I do not think I am ready for active speakers just yet, I am loving my tube pre and power amp setup ATM.

I did hear the Kii3s at the HiFi Show and did not like their sound, I prefer a warmer sound, like the Meridian actives at the show.

[reflux075]

A bit of an update everyone, I have combined a bit of the advice from a few of you and have got positive results!

Firstly, I have moved the left speaker to the right so my speakers are not set up symmetrical to the room.

The second thing I have done is increase toe in to get the cross point straight out from the tweeters to cross in front of me.

The last thing is I have got the speaker to point down quite substantially by using an extremely thick spike shoe on the back with Bunnings anti vibration squares under that and really thin spike shoes on the front.

There is now an acceptable amount of bass at my listening position, but there is still more bass when I stand up haha.

Not sure if the treble is more emphasised with the toe in or I have lost a bit of midrange but the sound is also a bit harsher or less warm.

Will keep tweaking and see how it goes!

[audiohifiaudio]

On 07/04/2019 at 11:10 AM, reflux075 said:

Hi peeps,

 

I have recently changed speakers and after a few months of moving them around to try and get the best placement I have discovered something quite frustrating.

The bass gets cut off ONLY at my listening position. The moment I stand up from the couch, the bass is all there, sit back down and the bass is gone.

I have tried moving the speakers right back against the wall, I have tried moving the speakers reeeeally forward, and it does not help.

I know my setup is not ideal but I don't really have to much chance of rearranging the room, peace with SWMBO is much better than bass.

I'm thinking I need some sort of room treatment?

I have never done any of this before and would appreciate some suggestions as I do not know my bass traps from my reflectors.

Some pics of my listening area below.

 

 

Take the spikes off the speakers.

[Primare Knob]

 

 

 

Not sure if the treble is more emphasised with the toe in or I have lost a bit of midrange but the sound is also a bit harsher or less warm.

Will keep tweaking and see how it goes!

 

That sure is possible. Towing in means that you are aiming the center of the speaker towards the listener. The center of the tweeter usually is more efficient by a few dB than the off axis. That is also true for the midrange driver but the effect is less than with a tweeter.

 

You can't do much about the bass being stronger when standing up, except raising your seat up, or use bass trapping on the ceiling. Try your luck with the height of your seating positions, as sometimes small increments do make a difference.

 

Edit:

It is also possible that by moving and towing in your speakers that a first reflection point moved from a position where it previously was getting diffused by a cabinet/book case or absorberd by a curtain.

 

[reflux075]

18 hours ago, audiohifiaudio said:

Take the spikes off the speakers.

Will try that, it's a bit of a PITA with my speakers, they're 80kg each.

[audiohifiaudio]

1 hour ago, reflux075 said:

Will try that, it's a bit of a PITA with my speakers, they're 80kg each.

You can go to Clarke rubber and buy rubber black mats. This will also help plus not damage your floor boards.

[reflux075]

Thanks for the tip, was a bit worried about that.