Home Studio: Room Modes and Why They ABSOLUTELY Matter

Earlier this week, we here at PAL talked about finding the perfect speakers for a home studio setup. We described the two kinds of studio monitors – powered and unpowered – as well as each of their inherent flaws. With powered monitors, you will need to connect them to a power source via an ac outlet but benefits from not needing anything else to function, specifically cables and a power amplifier. Unpowered on the other hand do need those things, but are usually more economically priced and can benefit from the setting of a power amplifier. Check out the entire article here for more information on the each of these monitors. Well, now that you know a bit more about which monitor is right for you, it’s time to decide where to place them in your home studio setup. Unfortunately, it’s not as easy as it sounds if you truly want the best setup possible. Because every room is different dimension-wise, every perfect setup for a room is different, meaning that there will be a few things one must understand and in turn apply to their specific environment. While most professional studios have the benefit of being constructed with these certain variables in mind, as well as wall mounted speakers, knowing a bit about how sound and frequencies are affected by the size and shape of a room can help you produce good mixes that will sound reasonably accurate on most other audio systems.


What You Should Know About Room Modes

Before we get started on where exactly studio monitors should be placed, there are a few things one should understand about why a certain setup works better than others, and unfortunately, it’sa bit complicated. As we all know, rooms for the most part are all different sizes and while one setup may work perfectly for a certain room, it will sound terrible in another. Most rooms are rectangular and shape and exhibit three different dimensions – length, width and height – all of which affect the way sound bounces around the room. When speaking of sound, we are actually looking at the frequencies coming off the speakers and because different frequencies travel at different wavelengths, they are affected differently by each room. The reason for this is because of Room Modes, which are the collection of resonances (the tendency for sound to oscillate at greater amplitude at some frequencies than at others) that exist in a room when the room is excited by an acoustic source such as a studio monitor.

Diangram A














Alright, now this part is important: room modes occur when a room dimension is an exact multiple of the half wavelength of a sound being played back . While you don’t have to know all of this in great detail, suffice it to say that depending on your room, you will have certain hotspots – three main ones to be in fact, one for each dimension – where certain frequencies overlap, causing a noticeable buildup of sound. Your job for a perfect setup is to diminish these hotspots, or cancel them out, as much as possible, resulting in evenly distributed sound. Take a look at diagram A for a visual of this. Also, not only will there be three frequencies at which you will expect to experience 'hot spots', but there will also be a whole series of modes at frequencies above each three of these that correspond to the multiples of the main mode frequencies. If that’s a bit too complicated, the good thing is that simply adjusting for the main frequency affected by the room mode will take care of the rest of the corresponding multiples. And if that wasn’t complicated enough, even the small variations of the corners of the room will give you extra “sub-hotspots” independent from the primary three, although these are not as intensely distinguishable – but believe me, they’re there.

All rooms have modal behavior but this will only become a problem when sounds become unevenly distributed, and unfortunately for those looking for a home studio setup, the smaller the room, the more uneven the frequencies will become. Things can get even worse if any two of the three dimensions of the room are equal. And if by chance your room is a perfect cube where all three of the dimensions are equal, the intensity of these hotspots will become gargantuan, meaning that certain frequencies will sound much louder than others even if the actual sound coming from the speakers is even. Again, looking at diagram A, imagine the blue line being doubled in the case of a room with two exact dimensions (because exact dimensions give you exact modes) and then TRIPLED when in a room where all three dimensions are the same – that’s a lot of uneven sound distribution to say the least! Pretty much, same room dimensions create hotspots at the same place which then add to each other – got it? Good!


More Wavelength, More Problems

Most modal problems like the ones mentioned above tend to happen with frequencies below 300Hz, or close to it, because frequencies above that are shorter and more closely spaced, resulting in more of an even sound distribution – but that doesn’t mean that frequencies above 300Hz don’t have their share of problems; at frequencies above 300Hz, pure physical sound reflection from a hard surface will become a problem, and in a smaller room, this problem becomes intensified.

Alright, now that we know about room modes and other sound problems inherent in smaller studio environments as well as how they specifically affect the way sound will be balanced, we can now talk about how to fix all of this, but that will have to wait. Come back tomorrow for tips on how to negate these problems and help on where exactly the best possible spot for your own home studio monitor setup will be. And just in case you still need some studio monitors of your own, check out PAL’s great selection of the monitors at the best prices right here!     




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