Why Is a Table Saw So Much Quieter Than a Circular Saw?

Shop safety is critical when working around woodworking tools. They are sharp, fast, and powerful. They are also incredibly loud. Noise induced hearing loss associated with woodworking is more common than you think, and is easily preventable with some caution and the right protection.

Some of the loudest tools we use in the shop are the circular saw and the table saw. They make quite a racket! But, if you've ever spent any time around each, you'll probably have noticed that they share neither the same pitch nor the same volume. A circular saw, on average, will be 5-10% louder than a table saw. This, of course, varies from brand and make, but as a general rule it holds true.

Let's break things down one by one and think this through.

The first thing that we have to look is the size of each. A good table saw is much larger and heavier than your standard circular saws are. This means that they are much more massive. With mass comes dampening.

Sound is a byproduct of waves passing through the air and into our ears. Those waves are produced by the vibration of the object producing the sound. The more mass that something has, the less it shakes and shimmies, and the less likely that it is to produce sound.

The heavier your saw's table is, the less it is likely to rattle and the less sound it is going to make. A contractor saw is going to make more sound than a cabinet maker's saw. A saw with a cast iron top is going to make less sound than one with a plastic top.

A lot of the sound we hear in a circular saw is the spinning of the saw itself. This vibration rings and emits a loud noise. In a table saw, both the arbor and the flange which holds the saw in place are significantly larger. These hold the saw blade more rigidly and reduce sound.

The quality and balance in your saw's motor is going to be much higher in a table saw. This is especially true in a cabinet maker's saw.

A circular saw is also going to be a direct drive or worm gear attached to the motor, where the saw is connected directly to the motor via the arbor or via a gearing mechanism. Most quality table saws will be belt driven, which will produce less vibration as there will be a dampening effect from the belt.

For a table saw you will generally have a larger blade of higher quality. That means that it is more balanced and its angular momentum will be evenly distributed along the circumference of the blade. I think more important for our purpose is the size of the blade. In circular saws they tend to be smaller and run at higher RPMs. There is, of course some overlap, as some smaller table saws will have smaller blades and some circular saws will have larger blades. But a small circular saw, say an 8 inch blade, will spin faster than a larger cabinet saw with a 12 or 14 inch blade. The faster RPMs will directly translate into a louder noise via vibration.

I've laid out the different theories that I have. What do you think causes the difference in noise levels between circular saws and table saws?