Advice on Setting Up Speakers

I posted this in a rather obscure thread in the Music forum. I think it belongs in the Hardware forum, and deserves its own thread. It's a quick and simple summary of things I've learned so far about setting up speakers. I hope other members find it useful.

Apologies in advance for the double post. Any comments/questions/violent disagreements, please post 'em here!

 

Can you recommend anything for my poured concrete garage-turned-home office?

Oddly enough the walls seem to absorb as much as they reflect.

 

It is presumptuous and pointless to recommend detailed speaker placements without detailed knowledge of your room. Each room has its own specific problems.

I have found, however, that the rule of third is a simple starting point that has helped me tremendously in the past in just about any room.

Simply draw two lines to divide the length of your room (the longest dimension) into three equal thirds. Place the speakers along the first line and your listening position along the second line. That's it!

You have now avoided the most unpleasant problems in the room (bad reflections, boominess, etc.). From this starting point you can now fine-tune the placement with the speaker separation, toe-in, wall treatment and so on to improve the sound depending on the specifics needs of your room.

 

I hope this isn't aimed at me! In general, I agree with your approach: find a rough starting point and go from there. Whether it's rule of thirds, Cardas, or Allison, in the end you have to put in the hard work to fine-tune your own set-up. What I hoped to do with my rather long post was to set out some helpful guidelines on how to do it.

 

I'm afraid I've never dealt with a room like this, so I have no detailed advice to offer. It would be interesting to treat the first reflection points with foam and see what difference it makes to the sound. Just a quick-and-dirty, temporary job to see what happens. Let us know if you do it!

 

Click here to check out FREEWARE for speaker & room setup

 

The best rule is to trust your ears. All these guidelines are just that - guidelines. After you have found the ideal listening position (see Stereophile's website for this) and treated your listening room, THEN spend about three evenings moving your speakers around and toeing them in at different angles. I can almost guarantee you that the very best speaker position will not exactly match any formula.

 

Absolutely. Just an inch or two front, back or in-between makes a huge difference. It may take longer than 3 days but you'll know when you get it right. Toeing is essential, and the best toeing may not match what the speaker's manufacturer recommends. It's your room and your ears. When I first bought my current speakers I experimented for months until I found the right place. I have not changed or moved the speakers for at least 8 or 9 years. Keep notes during the process (write down the exact distances from each corner of the speaker to the walls). Once you find the best place, make sure you keep these distances in a handy place and check them every so often.

 

Yes, but let's not throw out the guidelines! I agree that there is no "magic formula" for finding the ideal set-up. In the end, you have to use your ears. But, you have to know what you are listening for, as well as what the variables are. Those are the things I was trying to lay out in my initial post.

I think those who have responded so far are more "advanced", if I may put it that way, than those whom I was writing for. I had the complete neophyte in mind. It's not so long since I was one.

P.S. It's hard to get the bass reasonably flat by ear, unless you're someone like Steve, who EQs recordings all day long for a living. For the rest of us, that Rat Shack meter sure comes in handy!

 

RZangpo2,

No, the post was not an attack on you. I apologize for any unfortunate choice of words which may have led you to believe otherwise.

My main point was simply that without knowing the particular dimensions and characteristics of the room, a very detailed guideline is not very useful.

My preference is for a broad guideline to help a novice quickly find a good starting point. Then provide a simple strategy on how to fine tune the sound from that starting positon to the optimal position. That's all.

 

We agree on all points, then. Though I may have fallen short of the mark in the "broad" and "simple" categories.

But it's such an important topic, and one on which there is a real lack of helpful information. The emphasis here is on "helpful". There is no shortage of information on the subject, but to the neophyte who has just unpacked his speakers, it's not always arranged in a useful way. I tried to write the step-by-step guide I wish I had had when I started out.

Maybe I should have numbered the paragraphs. One of the things I was trying to do was set out an order in which to take the various steps. I find the task too overwhelming otherwise. I tried to set out the following steps in their rough order of importance: (1) find a starting point for the speakers (Allison rule); (2) find a starting point for the listening position (left-right, up-down, forward-back); (3) speaker separation; (4) toe-in; (5) bass response; (6) treating the first reflection points.

I do hope someone is helped by it. Maybe I should revise it to make it easier to follow.

 

Randy W,

I believe much more strongly than you do in the importance of a broad guideline to quickly find the "ideal listening position" as you called it (I call it a good starting point) especially to new audiophiles. I agree with you that our ears are our final judge; that goes without saying. But they are best saved for the fine-tuning stage.

There are literally an infinite number of speaker positions within a room and our ears not to mention our arms will be awfully tired if we tried too many of these positions. A good guideline saves us a great deal of time and elbow grease to get to a good starting point; it also tells us how to proceed from there methodically to get to the Promised Land. What you suggested about spending "three evenings moving your speakers around and toeing them in at different angles" is exactly that—a guideline.

Finally, I fully agree that the goal is not to "exactly match any formula." We start from a good position as suggested by a guideline—there are surprisingly few good starting speaker positions within each room—then we fine-tune with small, methodical adjustments of various parameters (speaker separation, toe-in angle, listening distance, room treatments, etc.) as suggested by a guideline. It is during this fine-tuning stage that our ears really come into play. I agree that once we arrived at the optimal position, neither you nor I care how well we match any formula. But to get there with a minimum of grief, I believe a good, borad guideline is essential, especially to newcomers.

 

Please bear with me. Since re-reading my initial post, and reading some of your comments, I've concluded that my attempt to set out useful guidelines for beginners was not as helpful as it might be. Specifically, it's a little too dense. I was trying to make a potentially overwhelming subject more manageable, but I ended up with a dense block of prose that may be overwhelming in its own right.

So I've divided up my article into bite-size pieces with sub-headings. I'm sorry again for the multiple posts, but I think this may make the article more useful to its intended audience, i.e., those trying to set up stereo speakers in a room for the first time.

Initial Placement for the Speakers. Start by placing the speakers according to the Allison rule. The Allison rule uses the distances from the center of the woofer to the front wall; side wall; and floor. The longest and shortest of these three distances should differ substantially, and their product should roughly equal the square of the middle distance.

Other guidelines include the Cardas method, the rule of thirds, etc. These may work for you just fine. In any given case, though, I would double-check these to make sure they don't violate the Allison rules too badly.

Note that applying the Allison rules to your room won't give you a single pair of speaker positions. Assuming the height of your speakers is constant, it'll give you a pair of diagonal lines that get closer to the side walls as they get farther from the front wall, and vice versa. Put the speakers somewhere along those lines, and then adjust according to the principles below. Try not to have any objects between the speakers (although if such an object is far enough behind the speakers, it may be OK), or between the speakers and the listening position. Also try to have the speakers placed symmetrically with respect to all the room boundaries (front-back, left-right, ceiling-floor).

This is only a rough starting point, designed to avoid the worst room resonances.

Initial Placement for the Listening Position. Once you find a starting point for the speakers, you can find a good preliminary listening position this way. On the left-right axis, the listening position should be centered between the speakers. On the up-down axis, multi-driver speakers will have a vertical "window" where the drivers are in phase. Move slowly up and down until you find that "window". Use a mono recording for this. When your ears are at the correct height, the sound will seem to "pop" into focus, and you will have a greater sense of hearing "into" the (mono) soundstage. When you leave the vertical "window", the sound will seem to flatten and lose coherence. Set the height of your listening seat so your ears are within this window.

Generally speaking, your ears will be in the window when they are on or slightly below tweeter axis. The drivers should be in phase within a 5 to 10 degree angle centered on this axis. But experiment and find the window boundaries for yourself.

On the front-back axis, you need to be far enough away from multi-driver speakers so that the sound of the drivers can integrate. Check this by moving forward slowly (centered at the listening height, of course). Again, when the sound seems to flatten and lose coherence, or when you begin to hear the individual drivers (e.g., woofer and tweeter), you are too close. That is the forward limit. To find the rearward limit, move back gradually until the bass begins to "boom" or "thicken" due to the boundary effect caused by proximity to the rear wall.

Angle of Separation. As for angle of speaker separation and toe-in, I personally like 90 degrees separation, with speakers pointed directly at my ears. The 90 degree separation is the only way accurately to reproduce Blumlein stereo, and sounds fine with most other stereo recordings as well. Other angles can also work fine in terms of imaging and soundstaging, so long as speaker placement is symmetrical and the listening position is centered between the speakers.

Generally speaking, 60 to 90 degrees separation is reasonable. Much more or much less may have a deleterious effect on the soundstage.

Toe-In. Pointing the speakers directly at the ears gives good tonal balance with speakers (such as monitors) that are designed to have flat frequency response on-axis. It also minimizes side-wall reflections. Other degrees of toe-in can also work fine, however. If you don't point your speakers straight at your ears, try to find a degree of toe-in that gives a solid center image. Test this by listening to a mono recording of a solo instrument or voice. The sound should appear to float dead-center between the speakers.

Toe-in also affects tonal balance. Speakers are brightest on-axis. If your speakers sound too bright pointed straight at your ears, toe them out a little. However, if you toe them out too far -- especially if they are near the side walls -- you will get more side-wall reflections. This can interfere with soundstaging and imaging.

Soundstaging and Imaging. Mono. In general, try to get mono right first; then stereo. Mono images should "float" dead-center between the speakers. If the mono image seems to spread out or "splash" at some frequencies, or to be competing with phantom images at the speaker locations, early reflections may be interfering with imaging. This can be dealt with by toeing the speakers in more, by sitting closer to the speakers, and/or by treating the first reflection points (see below).

Stereo. If you listen to a stereo recording with your eyes closed, you should not be able to hear exactly where the speakers are in space, on either the front-back or right-left axes. Images of individual instruments and voices should be solid and precisely located in space. The ambience of the original recording venue should be spread out around. It is difficult to judge this using recordings, because it is impossible to know what spatial information was originally encoded on the recording until you play it back. Circular logic, in other words. One method of dealing with this is to use single-point stereo, i.e., Blumlein recordings for this purpose. This method accurately records an image of the recording venue as "seen" from the microphone location. If a recording made this way sounds right, your speakers are well set up.

Bass Response. Check the bass response from the listening position with an SPL meter, from 20Hz up to about 250 or 300Hz. Adjust the listening position and speaker locations until you find the best compromise between reasonably flat bass response on the one hand, and good imaging and soundstaging on the other.

First Reflection Points. Finally, treat the room's first reflection points. This will improve soundstaging and imaging, and possibly tonal balance as well. It's easiest to do this with a helper, a small mirror, and (if you intend to treat the ceiling) a ladder. Sit at the listening position and have your helper slide the mirror flat along the wall. When you can see any part of the speaker in the mirror, mark that position. Do this for the left-right and front-back walls, as well as for the ceiling and floor. There will be twelve first reflection points in all; six for each speaker.

I treated the first reflection points in my room with four-inch, medium-firm upholstery foam that I bought from an upholstery store. This can be cut with an electric knife or razor blade, and attached to the walls with ordinary push pins. It's very ugly. A more expensive option is a specialty acoustic foam such as Sonex. In a domestic environment, strategic placement of thick rugs or drapes, or shelves full of books or records, may accomplish the same purpose. Don't make the room too "dead" or it won't sound natural. Just try to make sure the first reflection points are covered. Beyond that, if conversation sounds natural in the room, music will, too.

Conclusion. That's it! It's a lot of work, but you can spread it out over a period of weeks or months. Every one of the parameters affects every other, so when you change one thing, you may have to go back and change others as well. Take your time.

I would recommend doing this before upgrading anything in your system. It's free and will make your system sound much better. Also, properly set up speakers will let you hear more accurately the effect of other component changes on your system. In other words, don't spend a dime on your system until you do this! You'll save money and be happier in the long run. I guarantee it.

 

Very interesting stuff. Thanks guys.

 

In my previous job, I often had to write instructions for new and difficult technical procedures to be carried out in the field by people who are not terribly familiar with nor necessarily interested in new technologies. I found out that the worse thing to do was to give them step-by-step instruction sheets like those we often find with do-it-yourself kits.

The optimal approach seemed to be the following. First give a very short summary of what we are trying to accomplish--the goal. Then briefly describe how we are going to accomplish it--the strategy. Finally summarize the various parameters we will try to change or the main steps we must go through--the method. Without this preamble, the step-by-step instructions are often difficult to understand and hard to follow no matter how well organized they are.

My writing instructor used to tell me that easy writing makes for very hard reading. Simple writing is very hard work that requires hard thinking. There's no way around that. Good luck to you on your revisions. It's gonna be hard work.

 

Hmm... back to the woodshed! Don't know if I have the time or the skills to do this properly. Maybe some other contributor to this thread will be inspired to help out. (*hint*)