How to position your speakers perfectly

[HdB 210]

… back again!

 

It was mentioned awhile back about the different effects of room boundaries (SBIR) - what wasn't mentioned was the benefits of using diffusers at some of those boundaries (behind the speakers, for example) and absorbers at the first reflection points on the side walls - this has been mentioned quite a bit elsewhere but it is still worth repeating it again

 

These 2 procedures contribute much more to the 'stereo effect' than anything else - the rear diffusers, if positioned correctly, will increase the delayed indirect sound content (longer than 10mSec) and the side wall absorbers will reduce the shorter indirect sound reflections (less than 10mSec) - these contribute directly to the precision of the stereo image and it's a subject well worth looking into - Room Boundary Effects aren't mentioned much in the hifi press but are a regular discussion in all 'pro-audio' areas

 

As all things are never equal (just a phrase!) there is the reflections off the floor and from the ceiling just to add to the confusion, so just approaching the positioning of the speakers & the listening position by practical moving/turning/tilting the speakers is a lot quicker and you 'learn to listen' rather quickly - actual room test measurements are extremely useful to show how well your system is functioning and to sort out some hidden deficiencies/problems, particularly in the bass/mids area.

 

I've seen quite a few people going to incredible lengths to obtain a reasonably flat freq response (+/- 3dB) at the listening position (particularly via a dsp) but to still find it unsatisfactory for music - controversially, some people (me too!) just prefer a non-linear freq response and this changes with different types of music and also the volume - weird thing, this music reproduction, eh!

[vivianbl 157]

On 02/12/2019 at 12:18 AM, HdB said:

… back again!

 

It was mentioned awhile back about the different effects of room boundaries (SBIR) - what wasn't mentioned was the benefits of using diffusers at some of those boundaries (behind the speakers, for example) and absorbers at the first reflection points on the side walls - this has been mentioned quite a bit elsewhere but it is still worth repeating it again

 

These 2 procedures contribute much more to the 'stereo effect' than anything else - the rear diffusers, if positioned correctly, will increase the delayed indirect sound content (longer than 10mSec) and the side wall absorbers will reduce the shorter indirect sound reflections (less than 10mSec) - these contribute directly to the precision of the stereo image and it's a subject well worth looking into - Room Boundary Effects aren't mentioned much in the hifi press but are a regular discussion in all 'pro-audio' areas

 

As all things are never equal (just a phrase!) there is the reflections off the floor and from the ceiling just to add to the confusion, so just approaching the positioning of the speakers & the listening position by practical moving/turning/tilting the speakers is a lot quicker and you 'learn to listen' rather quickly - actual room test measurements are extremely useful to show how well your system is functioning and to sort out some hidden deficiencies/problems, particularly in the bass/mids area.

 

I've seen quite a few people going to incredible lengths to obtain a reasonably flat freq response (+/- 3dB) at the listening position (particularly via a dsp) but to still find it unsatisfactory for music - controversially, some people (me too!) just prefer a non-linear freq response and this changes with different types of music and also the volume - weird thing, this music reproduction, eh!

Yes, agree with your suggestions and observations. I’ve been playing around with speaker positioning and have got to a reasonably balanced spot where small adjustments of speaker position are making significant difference, but find that I now have to readjust volume controls each time I change CD or Vinyl. Not sure why that is. Unfortunate, have to do this manually- no remote!. 
 

Also wish I could have a remote control mechanism to move/ minor readjust  the speakers to get the best out each recording!!😉😃

Edited December 4, 2019 by vivianbl

[almikel 1,629]

7 hours ago, vivianbl said:

but find that I now have to readjust volume controls each time I change CD or Vinyl. Not sure why that is. Unfortunate, have to do this manually- no remote!. 

Each mix on every CD/Vinyl/Flac will have a different volume - don't you change the volume on how loud you want to listen? constant volume should be left in the domain of muzak, not hi fi.

 

I do love a remote with EQ adjustment to dial treble/bass up and down.

 

mike

[HdB 210]

Yeah, the re-emergence of tone controls plus the 'dialup' added analogue coloration  - it's been a long time coming.  This should evolve into simple or arranged dsp settings, I think - or packages, like in Audio Weaver, for example.

[Satanica 1,579]

15 hours ago, almikel said:

Each mix on every CD/Vinyl/Flac will have a different volume - don't you change the volume on how loud you want to listen?

Nope.

 

15 hours ago, almikel said:

constant volume should be left in the domain of muzak, not hi fi.

It should be but we know how that's ended up.

Here's a solution that works well: https://wiki.jriver.com/index.php/Volume_Leveling

[vivianbl 157]

18 hours ago, almikel said:

Each mix on every CD/Vinyl/Flac will have a different volume - don't you change the volume on how loud you want to listen? constant volume should be left in the domain of muzak, not hi fi.

 

I do love a remote with EQ adjustment to dial treble/bass up and down.

 

mike

In the previous settled speaker position there were specific CD/ vinyl which were considerable louder or softer than the standard position of the volume control, but the majority of the sources were okay at the position- so had to adjust on a few outliers. Now having to adjust in most cases!

 

I don’t get accused of listening to Musac, by family and friends! I like to experience a musical performance 😃

[Rup 21]

On 04/12/2019 at 1:37 PM, HdB said:

Yeah, the re-emergence of tone controls plus the 'dialup' added analogue coloration  - it's been a long time coming.  This should evolve into simple or arranged dsp settings, I think - or packages, like in Audio Weaver, for example.

talking about DSP how about software like; Sonar works room correction ?

[almikel 1,629]

On 08/12/2019 at 2:42 AM, Rup said:

talking about DSP how about software like; Sonar works room correction ?

I've never tried it, and from their website there's not much info on how it works - but it appears to apply EQ based on multiple mike positions, which is good, but costs around AUD$400, and is targeted at studios running a Digital Audio Workstation (DAW), which is likely fine if your source is a PC.

 

DSP (and EQ generally) can do great good when applied well, but greater evil when applied poorly

 

For room correction I prefer to maintain a high level of control over what EQ and delay I apply - using old school IIR EQ (parametric minimum phase EQ) but leveraging the convenience of DSP for implementation - delay is particularly tricky without DSP, and trivial with DSP.

 

IMHO DSP/delay capability is an essential tool for achieving great "in room bass" particularly when integrating 1 or more subs into the system...

 

...if integrating multiple subs - providing you have access to EQ/Delay (eg via a miniDSP HD), and a measurement microphone and laptop -  I'd recommend free tools such as REW and MultiSub Optimizer (MSO), before costly tools such as Sonarworks.

 

If you don't have subs, then REW and a measurement mike is still useful to measure what's going on with the bass in your room...

....and will help you make informed decisions on when and more importantly when not to apply DSP/EQ.

 

Mike

[almikel 1,629]

On 01/12/2019 at 11:18 PM, HdB said:

It was mentioned awhile back about the different effects of room boundaries (SBIR) - what wasn't mentioned was the benefits of using diffusers at some of those boundaries (behind the speakers, for example) and absorbers at the first reflection points on the side walls

Absorption at 1st sidewall reflection points is contentious - Toole recommends that sidewall reflections should have the same spectral content (frequency response) as the direct sound from the speaker.

Toole's recommendation is based on the assumption that the speaker "off axis" response is consistent with the "on axis" response.

Toole's definition of a good speaker is a smooth frequency response on and off axis, with the response off axis smoothly falling the further off axis you go.

Placing absorption at 1st sidewall reflection points will always absorb the top end more than the bottom end, so the sidewall reflections won't have the same spectral content...assuming you have a speaker with good/consistent "off axis" response.

 

Typical box speakers (eg a dome tweeter crossing to a cone mid woofer) don't have a smooth off axis response, especially around the crossover where the mid woofer radiation is starting to narrow, and the tweeter has much wider coverage.

Under this scenario sidewall absorption may likely assist in masking the large variation between the direct sound and the quite different off axis sound coming from the speaker and being reflected at the sidewall.

 

On 01/12/2019 at 11:18 PM, HdB said:

the rear diffusers, if positioned correctly, will increase the delayed indirect sound content (longer than 10mSec)

A Quadratic Residue Diffuser (QRD) - as an example of a diffuser - does work by delay, but the delays are minuscule, and the effect is sound waves impacting the diffuser are scattered in different directions rather than reflecting like a mirror.  This can mean that some of the scattered sound reflected from a diffuser hits other boundaries before getting to the listener (increasing delay), but delay is not the goal - maintaining treble in the room whilst reducing comb filtering from strong specular reflections is what diffusers are meant for.

 

Diffusers have their limitations:

• just like absorption, they get big (deep) if trying to diffuse at lower frequencies
• QRD's have a recommended minimum listening distance of 3 x the longest wavelength diffused (lowest ferquency)- sit too close and you will hear "artifacts" from the diffuser as it takes distance for the "diffuse" sound field to develop - not an issue with diffusers on the front wall behind the speakers
• diffusers such as Binary Amplitude Diffusers (BAD panels), don't generate as much diffusion as QRD's, so the minimum listening distance could be relaxed

On 01/12/2019 at 11:18 PM, HdB said:

there is the reflections off the floor and from the ceiling

No contention here - reduce these via absorption or diffusion as much as possible (but if using diffusion remember the minimum listening distance constraint).

A good rug on the floor or carpet between the speakers and the listening position is always recommended.

Ceiling mounted Skyline diffusers are very popular - these are 2D QRD diffusers - the minimum seating distance applies - if sourcing commercially get the specs for the lowest frequency diffused.

 

To determine the minimum listening distance you use the formula:

V (speed of sound) = frequency x wavelength

Use 344 m/s for V

Say the lowest frequency diffused is 3kHz

344 m/s = 3000 Hz x wavelength (m)

wavelength = 0.115 m

Minimum listening distance is 3 x wavelength = 0.344m or 344mm - completely fine for a ceiling diffuser - or a diffuser placed anywhere further than 350mm from the listening position.

 

cheers

Mike

[Southerly 102]

Unless I missed it scrolling too fast through this thread, no one has mentioned a simple and effective means of precise speaker placement - using wheeled transport boards. I bought mine from the  German discount supermarket chain, Aldi here in France, they cost me €8.99 each, they are also excellent in their intended purpose of moving heavy furniture, each can support 250K. They make it a doddle to move heavy speakers until you have found that sweet spot. If you have a carpeted and wooden floor - see below.

 

I bought mine because the music room has a suspended wooden floor. As the house is rented I cannot use Philips screws to locate the speaker spikes into and this  anyway cannot cure only reduce the bass and detail loss with this type of floor. I intend to keep the speakers on these boards and use some freebe marbles slabs I have on top of the boards . This will definitely improve the sound but of course it also introduces Sod's law I shall now have to make a box to sit my listening armchair on so that the Toningen tweeters are level with my ears.

[JPete9 473]

I used REW and measured many hundreds of times, with my speakers and listening position calculated in everyone online calc i could find. then some treatment, more measuring and finally produced some PEQ values...at this point you're familiar with your test songs and small changes are quite noticeable. Instead of buying a DSP i tried using jriver built in PEQ and added the values....still got experimenting to do, but i am not sure i prefer the flattest, best measuring EQed sound.

 

After everything. If i had just used a calculator and positioned them i would've saved a lot of time...but i have enjoyed learning...but dont become a slave to the measurement. Everything you read says done have your speakers off the wall, but to me they sound better...there is a lushness to the mids that vanishes when they are against the wall.

Edited January 25, 2020 by JPete9

[elmura 35]

I occasionally use the guidance from some fairly simple calculations to place stereo speakers. It's the Cardas approach. 

http://www.cardas.com/room_setup_main.php

Here's the link to a calculator 

http://www.cardas.com/room_setup_calculators.php

 

My findings is that it is very difficult to apply in the average lounge room or even dedicated media room as it places the speakers quite close to each other, and the listener very close to them.

 

In my own dedicated home theatre room, with dimensions 6m x 4m x 2.7m. I apply a combination of factors that try and meet the following criteria for both home theatre and critical stereo listening

 

1. At least 0.5m from front and side walls.

2. Get the listening position close to an equilateral triangle for a great soundstage

3. Ensure centre speaker-to-listener distance matches main speakers-to-listener distance whilst keeping it at least 0.5m from front wall.

4. Toe in to minimise audible side wall reflections and maintain the speaker's on-axis frequency response

 

The result is main speaker woofer centre to side wall of 0.6m, and 1.1m to front wall. With speakers 2.8m apart (centre-to-centre), and speaker:listening distance at 3.1m. I sit around 4m from front wall

 

Measurements with a Radio Shack SPL meter have found it still lacking however. I get a massive boom around 80Hz from the main speakers and the sub exaggerates it. Maybe the raised rear platform is the cause (timber framed, particle board floor).

Maybe I need a tuned bass trap??

 

[Pim 206]

On 05/02/2020 at 4:12 PM, elmura said:

I occasionally use the guidance from some fairly simple calculations to place stereo speakers. It's the Cardas approach. 

http://www.cardas.com/room_setup_main.php

Here's the link to a calculator 

http://www.cardas.com/room_setup_calculators.php

 

My findings is that it is very difficult to apply in the average lounge room or even dedicated media room as it places the speakers quite close to each other, and the listener very close to them.

 

In my own dedicated home theatre room, with dimensions 6m x 4m x 2.7m. I apply a combination of factors that try and meet the following criteria for both home theatre and critical stereo listening

 

1. At least 0.5m from front and side walls.

2. Get the listening position close to an equilateral triangle for a great soundstage

3. Ensure centre speaker-to-listener distance matches main speakers-to-listener distance whilst keeping it at least 0.5m from front wall.

4. Toe in to minimise audible side wall reflections and maintain the speaker's on-axis frequency response

 

The result is main speaker woofer centre to side wall of 0.6m, and 1.1m to front wall. With speakers 2.8m apart (centre-to-centre), and speaker:listening distance at 3.1m. I sit around 4m from front wall

 

Measurements with a Radio Shack SPL meter have found it still lacking however. I get a massive boom around 80Hz from the main speakers and the sub exaggerates it. Maybe the raised rear platform is the cause (timber framed, particle board floor).

Maybe I need a tuned bass trap??

 

I've seen where they use the raised platform as a bass trap. Maybe cut the front open, fill er up with insulation material and cover it with some material.

[elmura 35]

Interesting. It already has a small opening with a lid on one end. I'd have to blow cellulose insulation in to reach all around.

 

I was wondering how it would sound mounting a custom sub woofer inside the platform

[Rup 21]

On 07/12/2019 at 5:42 PM, Rup said:

talking about DSP how about software like; Sonar works room correction ?

I've tried the headphone version. It works but I do feel that I hear all the processing going on. 

[Rup 21]

this one is very much to the point

 

Edited March 29, 2020 by Rup

[hometheatrebugbitten 48]

My wife helped with my home theatre room acoustics with out knowing it - she loves lots of pillows on the lounge (half end up on the floor when in use)

If I could make an open type pillow rack hanging from the ceilling it would be perfect.🙃

[Rup 21]

Yes, good idea!😀

[Rup 21]

On 31/10/2019 at 5:01 PM, Rup said:

 

 Best music for speaker placement and best speaker placement tutorial???

 

Having acquired a pair of Harbeth P3ESR speakers I'm having fun looking for the ultimate speaker placement. 

 

I have downloaded

The Visual Sound the Sound Liaison DXD Music Sampler 

as it was recommended to me as being a great speaker placement tool.

 (Using the coupon code “XFI2019” you can download the 352DXD for $16 or the 24/ 96 files for $8.)

Especially the phase coherent One Microphone recordings on the sampler seems excellent for that purpose: 

  Carmen Gomes inc. One Mic Recording Session       

 

  https://www.soundliaison.com/index.php/536-sound-liaison-dxd-music-sampler 

 

 

 

 

Good review of the Sound Liaison Sampler here; Recording Review: Taking a Listen to Sound Liaison’s DXD Music Sampler

Quote

Sound Liason’s DXD sampler, The Visual Sound, offers some of the most realistic sounding recordings I’ve heard, in enjoyable selections performed by excellent musicians. Most of the music on this sampler is decidedly laid-back, and audiophiles looking for an in-your-face sonic spectacular will likely miss the point. For engineer Frans de Rond and the excellent musicians heard on these recordings, it’s all about subtlFor engineer Frans de Rond and the excellent musicians heard on these recordings, it’s all about subtlety and refinement. Musically perceptive listeners will appreciate the efforts of all involved in making these fine recordings.

 

Edited August 26, 2020 by Rup