Kerry, I've gotten a bit of mileage from the Allison rule as described in TAS issue 127.
There the author describes the rule as follows:
"The distance from woofer to floor, side wall, and back wall should be as different from each other as possible and as a rule of thumb, the middle-sized distance squared should be close to the figure you get by multiplying the largest and smallest numbers."
It's a very general rule but it's gotten me about 2/3rd's of the way there. Beyond that, it took about 6 more months of moving my speakers every so often 6 inches this way or 3 inches that way until I became quite content with what I was hearing.
Buy ETF, the $400 get it done right the first time rule.
I recently tried out the Cardas method which produced a really noticable improvement in my setup. It exceeded my non-existent expectation.
For 30 years I thought I just instinctively knew where to put speakers in a room, then I found the Cardas formula; I did the math, moved the speakers to the recommended locations and the sonic image snapped into place to another whole level.
Be aware however, once you start on this route you are on a slippery uphill slope. You will find that the ideal room as certain length, width, and ceiling height ratios, and you may find you need more length to support your desired lowest frequencies, and you you might need any number of acoustical treatments, not too mention software spectrum analyzers and other tools. At the end of this journey is a realization that as important as you thought the room was is the discovery that the room has a HUGE impact on the final sound - and all the great gear in the world isn't going to overcome the wrong room. If you happen to have a good room on the other hand, you are on the road to potential sonic happiness. Good luck.
Recently, I have been experimenting with the nearfield speakers placement as suggested by Audio Physic and it has improved the overall presentation of the music that is being played. I will still need more time to optimise my placement but I initially started using the Cardas method awhile back which I thought worked well then. At present the palpable factor has moved up a notch but I seem to hear a bit more bass boom than before. IMO it is a trial and error process to fine tune speaker placements and there is no one "best" method/rules but perhaps some combination of methods.
Anyone know the link for the Cardas formula?
experimentation (obviously from what you're seeing here) is the key. I prefer an equilateral triangle. closer = better. Intimate and very deep soundstage. It's a one man listening seat, but there is always the couch for plain ole grooving to great sounds. However, when I want to enjoy what my rig can really do?--I pull my easy chair into a 6 foot equilateral triangle, take the grills off, seat back and look into a wall of sonic wonderment. Play around with your speakers. VERY room dependent, as you'll find out. You will certainly cut down the room factors with a closer seating arrangement. It has been my experience that most systems I've heard, the listener is way too far back from the speakers. It can be a visual turn off sitting so close, but not for this audiophool. peace, warren
I agree with the Cardas method which is where I put my speakers and did not even think about moving them after that, but do not have the link. Someone put the link in an old speaker post of mine about Maggie 1.6 speaker placement if you can find it.
I also like the TAS rule of thirds method. I think it is the best for integrating the bass with the rest of the sound but your speakers are really in the middle of the room with this method.
In my 22 x 13 room the speakers were 7.3 feet out in the room and 4.3 feet apart, which is the room measurements divided into thirds. The speakers really disappeared and the balance was great but I could not leave them there for long, just too intrusive.
This might be what folks are talking about when they mention Cardas speaker placement.Cardas Listening Room Design
The link for the Cardas Formula is on the Cardas website, the link is here.
Hope this helps. Bob
I started out with the Cardas room placement model, but in order to be at least 9 feet away from my speakers (according to the manufacturer), I had to move them back a bit.
Make sure that the distance (center of woofer) is different (by ~1/3) from the front wall to the side wall.
Do not place them that close to the side walls in order to mitigate first reflections.
Another "rule" that I read somewhere is that the best place for the speakers to be invariably has the worst WAF.
wow, sorry guys thought ETF was pretty much common knowledge.
Great easy to use program/measurement system that takes the theory out of speaker placement and lets you know what is going on with your system.
Price has gone up to $475, but that includes calibrated mic/ mic preamp. There are some new modules also to play with and add to the system that some may find useful.
If you have more than $500 in interconnects and not this system the cart is before the horse.
Don't forget the program for setting up specific brands of speakers in various sized rooms on the Rives site. I have found that it is a better starting point than Cardas but both are just starting points.
Its easy to get the initial triangle set up sounding good - its a totally different thing when you really get it perfected. That takes a lot of time and listening. Using the triangle as a basic configuration I like to get the bass down first, using a Radio Shack meter and a test disc. Once I've got the flattest bass I can get I start working on minimizing the effects of 1st reflections and getting diffusive materiels on the front and back walls. Then I start making small changes involving toe in, speaker/listening positions. Its taken as long as 3 months for me to really maximize a room set up. Be patient.
Cinematic Systems, Does this EFT devise measure things like width, height, and depth of image? Does it measure intensity of reflections from the rooms surfaces? Or does it just measure frequency response (not that that is a bad thing to do)?
Well width height and depth of image are a function of reflected energy which it does measure. So it can maximize the image your speaker system is capable of producing.
It will tell you how far your speakers are from the microphone, which can be very important, it will show a spectral decay plot and impulse response of your system and room which will help you find problematic reflections, vibrating objects etc.
It is extremely helpful for so little money.
It will rate your room acoustics versus RT standards and it does do frequency and phase.and many more things that you can read about on the website.
Click the link I provided in my 2nd post.
It will give you a visual tactile report your system's performance and "really" help you understand and solidify your system in a pretty short time.
Still use Cardas and Allison to get a starting point, but that's all they are is a good starting point.
Put them where they sound good.
I used the Cardas style method as well, following Diagramm C. Mainly because my room is 10.5 x 17 ft, exactly in the golden ratio. It worked really well, although I thought the palcement looked ridiculaous at first.
Furthermore, here is a great free link to Ultimate AV website (Don't run away because of the V in the titel), which offers an Excel spreadsheat to calculate room modes. The sheat further calculates the frequency peaks and nulls at your listening position. Excel calculation
All you need to do is enter your room dimensions and seating position and you get all the data you need. Nice way to play around with the seating position.
The programm also works for speaker placement since you want to avoid the speaker to sit a null point or maxima.
The interesting thing is: I took some measurements of my system/room a while ago using a corrected Radio Shack SPL meter, and I could see all the predicted "nulls" as little dips in the measured spectrum.
This is a really nice way of playing around and given my measurements it seems to work.
AND MOST IMPORTANT: Besides all this theory, don't forget to listen, your ears will tell you the best location. But the calculations might be a good starting point.
Hey Newbee how do you find that program on the Rives site ? Thanks Larry
On Audiogon - dammed if I know. He used to have a site on Audiogon, but I can't find it now.
HOWEVER!!!!!! Go to Audio Asylum - Rives is listed as a sponsor where he has all his products and a forum. Down load his Cara program - this should do it for you.
How about a step by step process for interpreting what the spreadsheet is telling us, how you use it with the Radio Shack SPL meter, and how you go about using the data to change your speaker placements and room treatments?
- tell us more about nulls and how the SPL meter predicts them, among othe things; Thx
- I read the link, but I still don't get it fully
Thanks Newbee,I will check out AA. Larry
Hi Hifi, sorry for the little information I provided earlier:
The spreadsheet calculates the room modes (=standing waves) for a rectangular (cuboid) listening room. It can tell you, whether there are "nulls" or "peaks" at your seating position or at the position where you place a speaker.
nulls = locations of no intensity at your seating position
peak = location of maximum intensity at your seating position
In order to calculate the "nulls" and "peaks" just enter your room dimensions and seating position in inches for the blue marked numbers on the right side/top area. In my case that results in peaks at the following frequencies:
Single peaks: 97.2Hz, 107.5Hz, 194.5Hz, 215.0Hz, and 291.7Hz.
Nulls: 53.8Hz, 161.3Hz, 268.8Hz
This means at my seating position I expect to see dips in the frequency spectrum at around 54, 161, and 269 Hz. Analogously for the peaks. You want to find a seating position in your room that gives you the least nulls and peaks. E.g. if I move my seat 6 inches back I have an additional null at 129.6 Hz that I can avoid by sitting just that little bit closer.
What is true for your seating position is true for the loudspeaker. If the speaker sits at an intensity peak position it will excite that particular room mode more efficiently, resulting in a strong increase in the sound intensity for that frequency. Thus one needs to avoid to place the speaker at that position.
As with respect to the SPL/radio shack meter measurement. A while ago I did a measurement of the frequency response of my system in my room measured at the seating position. I measured very sharp frequency minima around all the three frequencies 54, 161, and 269 Hz. These minima were up to 8 dB lower in intensity than the mean of the spectrum (actually 20dB for the 50 Hz dip).
The SPL meter measurement seems to be a good proof that these calculated nulls can easily be measured and probably be heard in form of some coloration.
How does this help you? Well, if you don't have a SPL meter and either a Rives audio CD of Stereophile test CD around to measure the frequency spectrum in your room, the spreadsheet might give you some hint which seating positions (or loudspeaker positions) to avoid without doing a measurement. I was quite amazed at the correspondence between calculation and measurement. I actually did the measurement before knowing the sheet and could not get rid of or explain the dips in the spectrum.
Also one more important comment: While you can balance maxima to some point can be treated via a room treatment (absorber) for that frequency, it is more difficult to get rid of the nulls. One solution would be to sit off center in the room (not a good idea in my opinion since you dont want asymmetric speaker placement because of soundstaging). However, a big shelf filled with LPs on the wall to the side of your seating position might break the symmetry and shift the null of the room mode)
In case you have any problems with the spreadsheet, please feel free to drop me an email.
Disclaimer: I am by no means a professional in room acoustics and treatment.
I hope this helps more than my initial post.
If you check my system and threads, you will see I have a bias for Magneplanars, but it seems I always end up incorporating the following:
1) unless specifically designed to be somewhere else, put your speakers as far out from the rear wall as possible
2) same for side walls given their associated reflections
3) moving your listening chair closer to the wall behind the chair will accentuate bass, usually with pleasant results
4) toe in is overrated --- more magical imaging and that wonderful "where is the sound coming from?!" effect comes from orienting the front of the speakers in a perfectly straight line
(Having said that, for some reason toe in seems to work better with many mini monitors placed far apart.)
5) the importance of the critical basic triangle cannot be overstated. Inches -- perhaps even centimeters -- count. Even if your speakers don't beam like Quads, they will still have a "sweet spot" when set up well.
(My audio mentor used to take 4 equal length pieces of string, attach them to the top corners of the speakers and then stretch them to the opening of his EARS to make sure both speakers were in perfect alignment.)
6) Further to imaging and toe in, speakers should be as far apart as possible, although in my experience this is rarely more than about 8 feet before the center fill collapses.
Even when the center does fill in nicely, I find > than about 8 feet gives a more vague and bloated "image".
Good question. Good luck.
Thanks to all for info especially 'Restock' for the explaination of the spreadsheet.Q.I have a terrible loungeroom/stereoroom setup. Room dimensions are H=2.7m,W=3.65m & L=7.6m. Unfortunately I can only place speakers on 1 width wall (3.65m) and it has a opening used as a walkway. The maximum I can have the FRONT of the speakers is 1.1m from back wall, otherwise it is in walkway.Other side has brick wall and is OK.
I currently have Audio Physics Virgo 11 powered by Krell.
Can anyone recommend solution?
Possible back wall treatment so speakers can be closer to wall?
My dim mind will greatly appreciate the light of experience.
You have a similar room and similar problem to mine. My old HIFI room is around 3.3m x 6.6m. I had used Thiels 2.2; ProAc 2.4 and the Virgo in that room before. When placing the speakers along the short walls, I could not get the ProAc and the Virgo to sound right, especially with the Virgo. The side firing bass were just too boomly.
Then I have the tried using near field placement, placing them along the long wall about 1.2 meters form the front wall and sit almost touching the back wall. You also need to toe in the speaker. It works! Everything opens up with imaging and details that I have never imagine it could!
There is detailed information at the AudioPhysics web site. Give it a try if you can afford for this method will place your speaker right in the center of the room making it useless for any other purposes! I hope there is no wife factors in the decision making!
MY speakers are 7 ft apart, 18 inches from side walls and 1 ft from back wall, I sit about 8 feet away, I can swear that sound is comming from my cente channel, and sometimes it nothers me because I think mids are getting "smeared"
I have a slight toe-in..and tried them straight facing, I guess I just want to know if thinking the sound is comming from center is a good thing or should I move around things as much as I can in a living room,,,wich aint much! thanks
Thanks Luna for your comments. Unfortunately I can't use the long wall, nor can I place the speakers in the centre of the room (I've checked the Audio Physics site before). I live in an apartment and the combination dining/lounge room has all other rooms coming off it, so it is a heavy traffic area. Hence, I can only have speaker fronts max. 4 feet from rear wall.
Will any sort of rear wall treatment help stop reflection and interference so I can push the speakers closer to the back wall?
If anyone can give suggestions/advice...much appreciated.
5 feet out farther that she likes. :)
I'm a long wall guy, pretty much always have been and i became especially committed to that placement once i got dunlavy's so your milage may vary here. The first order of business is to maximize seperation between the speakers without losing center focus..no toe in and no worries about bass response yet. With the dunlavy's you can't really spread them out too far unless you have a huge room, mine are spread about 10 ft apart.
Next up is dialing in the bass. I read a method somewhere where you start talking with your back against the front wall and start walking slowly into the room. Note where your voice changes and then when it changes again (i tried this as an after thought long after my speakers were dialed in and it ended up with my speakers in about the same place).
Usually, however, my method to dial in bass is to chose the general sopt i want the speakers out from the wall and then start moving the speakers forward and back trying to get the bass to tighten up, minimize boominess and maximize depth. Big steps at first followed by much smaller steps. I've had significant changes with an inch of movement. My guess is that even when using formulas the subtle differences in each room will allow fine tuning benifits to be found if you are patient. I've fine tuning this way over the course of days to get it best for the room. Use references recordings you know well and especially recordings with instruments that you known how they sound live.
Toe in is last and for that it's laser beam towards the ears to start and then tweak it outward to fine tune soundstage and, if needed to soften the highs. Cwlondon's statement about the overrating of toe in may be planer centric as his experience with the monitors seems to support. my speakers totally dissapear.
The long wall set up significantly helps in my current room due to a glass door on one side wall and a big bay window on the other. The long wall gives a lot of distance from the speakers to the first reflection point. some big house plants at those points helped further. My listen couch ended up against the rear wall. As Cwlondon indicates having the seat towards the back wall does help with the bass and here again inches count (what you are doing is manipulating where the speakers and your ears are relative to the room modes but doing it by ear rather than formula). I use pillows behind the head to get rid of rear wall reflections thus making a localized live end/dead end with the dead end at the back. It's pretty much a one head show in the sweet spot with acceptable results outside of it.
Diagonally across a room corner, so the central listening position is located at 1/3 room length and width.
ie: for 12x15 room, listener is 4' from one side wall and 5' from the back wall.
I've done some basic frequency response measurements with various arrangements, and this one produces by far the smoothest and most extended bass response.
It also tends to reduce the impact of early sidewall reflections, since the sidewalls "splay outward" like a horn, instead of being perpendicular to the speaker baffles.
From a speaker manufacturer now out of business, I learned to measure the center of the woofer to the floor and multiply that time 1.6. This is the distance to the side or back wall. This then is multiplied by 1.6 and that is the distance to the other. This is NOT likely to be pleasing to others in your life.
I have used the directions on the Cardas and Audio Physic websites with excellent results. AP has changed their directions, and they aren't quite as well written as in the past.