In part II of my article (part 1 is here) I am going to discuss how to achieve audio nirvana without upgrading your existing gear. At least we can try to get close anyway!
In my previous article, I briefly explained why the acoustics of your listening room are so critical.
Before we tackle speaker placement, which is to me the hardest part in the third article, I’m going to hopefully help you tame the acoustics of your room.
So let’s run a quick experiment to check if your room doesn’t sound too bad.
Pick a time when nobody is around at home otherwise they might think that you are insane…
Move around the room while clapping your hands. Depending on your location, you might hear more or less echo. The technical term for this is slap echo! Sounds obvious now doesn’t it?
This test is especially useful when clapping where your speakers are going to be located (it’s what the installers at Wilson Audio do for their installs :ed).
If you can hear a lot of echo, it means that the sound is bouncing repeatedly between 2 parallel walls. How can we stop this?
We have 2 options available to us: absorption and diffusion.
The first one is the easiest. It means that all the energy of the sound wave is absorbed and therefore cannot bounce back. In the real world, you cannot get 100% absorption but we are trying to limit the damage so any reduction of energy is a win for us. A typical DIY absorber could be large piece of soft furniture for example.
Diffusion is slightly harder to grasp. All the energy is sent back into the room but it is spread out and therefore looses some of its strength in a particular location. I will give you several examples later on but basically any uneven surface will behave like a basic diffuser.
I have mentioned before that most listening rooms are primarily used as living rooms. Having sound deadening treatment everywhere isn’t an option. No doubt you have heard about the wife acceptance factor also known as WAF! Let’s use it to our own advantage.
Our plan is to avoid bare walls at all costs because we already know that they are bad for sound.
I’m sure your partner has been nagging you for a long time to sort out storage issues: “We have to much stuff and nowhere to put it”.
It is time to get your credit card out and use your dusty tool box to put a new flat pack book case or shelves together. Any wall will do but whenever possible chose the wall behind your listening position to achieve the best results.
Large shelves filled with books, CDs or DVDs are fantastic diffusers! I had mine custom built by a local carpenter and it was cheaper than you think.
Now that we have sorted out one of the walls, let’s move on the others. I’m sure that it won’t take long to persuade your partner that your living room is due for redecorating.
A lick of paint won’t solve our acoustic issues but decorative accessories can make a slight difference.
Frames won’t help much but a large decorative padded patchwork or tapestry for instance are much better. The thicker the better as it will absorb a fair amount of energy.
My girlfriend wanted me for many years to hang on the wall an ancient throw rug passed between generations in her family. I never really liked it but after I realized that it could improve things, I happily hung it on the wall behind my speakers.
Soft furniture is fantastic too. Armchairs, bin bags, cushions etc… can tame nasty rooms. Try things out and see if it makes any difference.
Unless you live in a basement, you will have windows somewhere in the room. Glass is worse than concrete so yet again we need to absorb sound waves. Thick curtains are the best compromise and make sure they are drawn during serious listening.
What about corners behind the speakers? They are the worse place for bass so you will need a bit of absorption/diffusion there too. It is the perfect location for bass traps but the aim of the series of article is to avoid upsetting your partner.
Why not put a large CD rack there or another bookcase? Soft furniture can work very well too.
Wooden floors are in fashion at the moment. Unfortunately I don’t believe that they are the greatest for us audiophiles as once more it is a flat hard surface. A nice thick rug placed in front of the speakers can improve things.
Tiles are even worse so buy more rugs to make your room look cosy and sound great!
If you can’t move the speakers, move the chair.
Now that we have treated the walls and the floor, we need to worry about where we are going to sit relative to the speakers.
To achieve the best results, you shouldn’t be seated too close neither too far away from the speakers.
Your chair and your speakers should form a triangle. If x is the distance measured between each tweeter and Y the distance between you and the tweeter then Y should be greater than 1.1X and lower than 1.3X. This rule works best for standard dynamic speakers.
It is hard to achieve a perfect ratio on a permanent basis as most of the time it means having the sofa in the middle of the room or the speakers way too far in especially when your room is quite long.
If you can’t achieve this and you want to keep your wife happy, try moving your sitting position on a temporary basis. Just don’t forget to put the sofa back where it is normally placed at the end of the session…
Another option is to use a chair in front of the sofa when listening. Keep in mind that you will be sitting higher therefore the speaker tilting needs to be changed accordingly.
By now, I should have convinced you that room acoustics and speaker placement are very important.
There are a few other things which you can do to improve sound quality.
One of the things that Jim Smith mentions numerous times in his great book “get better sound” is to make sure that there is nothing between the speakers. He is fanatical about this!
In most installations, all the electronics are stacked up on a Hi-Fi rack right in the middle of the speakers. In other cases, there could be a large television, fireplace or even a piece of furniture.
So why is this bad? Sound waves (that’s music in our case) will bounce on any hard object. Depending on the shape of this object, the sound wave might even bounce at a different angle and introduce a phase shift on the returning signal.
Here is an example which happened to me.
Some time ago I decided to upgrade my CRT television for a flat screen. The old TV set was very bulky and most of all very deep. When my new plasma replaced it, I was very surprised to notice that the sound was more focused in the middle. Voices were more alive and instruments seem to spread out more evenly from left to right.
In the real world, it isn’t always practical to move your equipment somewhere else. So what can you do about it?
Try to keep your equipment racks as low as possible and behind the speakers. Wide AV racks are great for this as you can put your gear side by side.
For TVs, place them close to the wall. This will minimize the time difference between waves bouncing back earlier on the TV than on the wall.
The other reason for not having any Hi-Fi equipment between your speakers is that bass is usually quite strong there and your electronics might be affected by the vibrations (especially transports and valves).
So to summarize, furniture is good for absorption but not when placed between the speakers.
If you are really obsessive like me about sound, consider covering hard surfaces such as a large flat screen, radiator with a throw during listening. Results will vary depending on your room. If my room, the improvement is small but noticeable.
Loudspeakers need to breathe and anything in the way will affect sound.
A large coffee table with a glass top can make a noticeable difference so cover it or even better move it temporary out of the way.
I have seen so many systems where all the cables are tangled up together behind the rack but people don’t realize that High-end equipment is very sensitive to electrical interferences.
Any cables carrying analogue signals should be kept away from power leads and even digital cables.
If cable manufacturers sometimes put low pass filters in their interconnects and speakers cables that’s for a good reason!
As rule of thumb, keep analogue interconnects at least 20cm away from anything else.
Try to route all your mains cables on one side and the signal cables on the other.
The same applies to speaker cables. Keep them away from transformers and any other cables whenever possible. Another tip is to not coil long cables as it could affect their inductance.
High frequency signals generated by satellite decoders, televisions, game consoles and wireless routers can significantly affect your preamp and power amp.
For serious listening, it is best to switch off these devices off (i.e. fully disconnect them).
It is really worth experimenting with your cables and even your power distribution blocks.
You probably going to think that I am mad but when I change the position of my quintet (5 ways distribution block), I can hear the difference it makes on my system…
I have always placed the quintet vertically against the wall due to lack of space. One day, I decided to free up some space to lay it horizontal on the floor out of sight. After doing so, I noticed that the music had become a bit duller than before. I knew that the only thing I had changed was the position of the quintet. I decided to put it back where it originally was and suddenly the music got better. I have repeated this experiment several times and got the same results each time. Try to figure this one out!
You should regularly clean all your connectors as they oxidize over time. All this gunk will have a negative impact on the electrical signals carried by your interconnects.
You can find many specialist products on the internet such as Kontak. It is quite inexpensive and I got very good results. It might not make a huge difference on brand new equipment but for second hand gear you will amazed to see much “black stuff” is removed!
Most of the tweaks I have mentioned above will make a small difference on their own but when you start combining them the improvements will be significant. Just try things out and remember to have fun!