noise level comparisons re: jointers?

[John Dorough]

Big noise bothers me . . . and my neighbors. I am looking to purchase a 6" jointer. Is anyone aware of any testing reports that show the true difference in decibel levels between multiple-knife jointers and those with spiral cutterheads?

I found an article which contains the following: "One decibel equals the smallest detectable change in sound intensity. A 5-decibel increment is noticeable. And each 10-decibel increment is perceived as a doubling of loudness." This makes me believe that if a spiral cutterhead could make a 10+ reduction in the decibel level, that would be a truly significant factor in the jointer I might choose to purchase.

If no testing reports, how about anyone with actual experience of going from a multiple knife cutter to a spiral cutter?

Thanks, as always, for any help.

John

[Mike SoRelle]

Well, I can say my 3 knife regular cutterhead jointer is about 1/3 as loud as my dewalt 735 planer which I hold up as the gold standard for noisy equipment in my shop, nothing else even comes close.

Mike

[Mike Goetzke]

I believe 3 dB's is double the noise level.

I had an open stand 6" jointer and recently replaced it with a 6" closed stand and the non-loaded noise level is much less with the closed stand, but, running lumber through it sounds about the same. Maybe the spiral cutters will do the trick.

Mike

[Alan Schaffter]

Big noise bothers me . . . and my neighbors. I am looking to purchase a 6" jointer. Is anyone aware of any testing reports that show the true difference in decibel levels between multiple-knife jointers and those with spiral cutterheads?

I found an article which contains the following: "One decibel equals the smallest detectable change in sound intensity. A 5-decibel increment is noticeable. And each 10-decibel increment is perceived as a doubling of loudness." This makes me believe that if a spiral cutterhead could make a 10+ reduction in the decibel level, that would be a truly significant factor in the jointer I might choose to purchase.

If no testing reports, how about anyone with actual experience of going from a multiple knife cutter to a spiral cutter?

Thanks, as always, for any help.

John

Decibels are a base 10 logarithmic scale. I question the veracity of that article- a 3 dB gain roughly equates to a doubling of power or intensity. A 10 dB gain is a tenfold increase!!

Read about it in Wikipedia (http://en.wikipedia.org/wiki/Decibel)

As for straight vs spiral, I can't speak to the Grizzly cutter or some of the others, but a Byrd Shelix head is MUCH quieter than a standard blade jointer, and the difference is even more noticeable in a planer, especially if hooked to a DC which makes planers even louder!!

[JayStPeter]

I put a Byrd on my 8" jointer and the sound level decrease is significant. No measurements, but I sometimes have trouble hearing if the blades are actually cutting when edge jointing. Face jointing is a little louder, but significantly quieter than regular blades.
As mentioned earlier, the planer is easily the loudest tool in the shop. The wood is fed through it several times more than though a jointer. If noise is the primary concern, get the planer a cutterhead first. The jointer will be largely a waste of time if the planer still screams ... IMO.

[Mike Spanbauer]

Byrd's are MUCH quieter, but a jointer is the quieter rough preparation tool in the shop (vs. the Planer which is unreal).

the only time that my 3 knife PM60 makes a racket is during face jointing operations and generally that's less frequent than the edge jointing operations.

Also, for the db references.... a 3db gain is a doubling of intensity / power, but it takes 10 db to "feel" like a doubling to the human ear. I can't recall the science behind the mechanism and ear receptivity but that's what is commonly accepted as the "double" perception. It's also why wattage on stereo's is lame compared to clean output / distortion.

quality 25w tube amp > 100w solid state in almost every case for perceived quality at a volume.

Of course, it gets much more complex with audio given natural resonance, environment gains, etc.

The real reason to go with a spiral cutter head is performance, the volume is a nice bonus. Hearing protection is required in any event as all of these exceed 'safe' listening levels with no long term hearing damage risk.

mike

[Dick Strauss]

John,
I have used both types in different locations. Comparing an 8" Delta DJ20 vs a Grizzly 8" (G0593????) spiral jointer, I'd have to say the Grizzly was at least 10db more quiet while taking the same 1/16" pass on wood. The difference was definitely very noticeable.

Here's a link to a article that mentions the sound issue...
http://blogs.popularwoodworking.com/editorsblog/CommentView,guid,be631cf9-861c-4bb0-98d8-1e3fdbc813a3.aspx

PW's apples to oranges comparison (12" Bridgewood spiral vs 12" Delta standard) seems to suggest that a jointer with a spiral head will get 8db louder as you take a 1/16" pass. However, the standard head became 23db louder while taking the same 1/16" pass on the same wood. This might suggest the spiral heads could be 15db more quiet in operation (Wow!).

A better test would be to do the comparisons on the same model or same machine. Try contacting Grizzly (Shiraz Balolia???), Delta, or PM to see if they have rough numbers for sound reduction for spiral heads.

Let us know what you find.


Thanks,
Dick

[John Dorough]

To: Alan, Mike and Dick,

Thanks for the information. I did go to the Wikipedia site referenced by Alan. That linked me to the very interesting site to which I have provided a link, below. Go to the site, and you will be able to hear differences in 1 decibel and 3 decibel changes in sound. There are other interesting items, as well.

For my ear, it seems that a 9-10 decibel decrease does make the noise seem only half as loud. How 'bout your ears?

http://www.phys.unsw.edu.au/jw/dB.html

[Ron Dunn]

Don't waste your time trying to guess changes in sound level and associate those with decibels. You won't succeed.

Your best method is to go to Radio Shack (if you're in the US) and buy a sound level meter. From memory they are around $30-40. I've also seen a Nokia handphone which has an in-built sound meter, but I can't remember which model it was.

[Mark Carlson]

John,

I put a byrd head in my 6in powermatic 54a jointer. The 1st thing I noticed was how much quieter the byrd head was than the stock 3 blade cutter head.

~mark

[David Giles]

Unless your dust collector is super quiet, the jointer noise may not matter to your neighbors. The loudest machine sets the overall noise level. If 2 machines each have 80 dbA noise, the combined racket is 83 dbA. So when the 200 dbA Dewalt planer is going, nothing else matters.

[Frank Drew]

John

Everything I've heard about spiral or helical cutterheads says that they're considerably quieter; for yourself, wear hearing protection, but if you're neighbors are giving you grief about the noise new cutterheads, expensive as they are, might be the way to go. I never had neighbor trouble but I was pretty religious with the ear muffs, even when using my cheap-ass Grainger shop vac which had the most annoyingly loud whine.

You can maybe make a sound-insulated cabinet for a dust collector.