Ok - bearing edges :)

keep it simple

Platinum Member
Another Andy "infothread", let's see where this goes :)

I'll kick off with describing some features, how they apply, & what they achieve. For the sake of removing terminology confusion, I'll describe the three edge features as follows: From the outside inwards - outer cut - crest - inner cut. Please use this terminology in questions & replies.

Angles:The most commonly used means of differentiating one edge from another, but angles in themselves, how relevant are they? The answer is, far less than you'd imagine in terms of general playing & sonic characteristics, but there are some finer aspects to this. One person's double 30 degree edge can be quite different to another's. Back in the day, the outer & inner cut angles were used as an indication of sharpness. A trend that continues through to today. Typically, a 30 degree angle would be regarded as less sharp than a 45 degree angle. Given little control over the crest form, this has some truth to it, as a more shallow angle will typically offer a larger crest radius when sanded to finish.

The crest:This is where the action is. It's the bit that interfaces dynamically with the head. It's by far the most critical aspect of a bearing edge, yet there's often little - no information revealed about it in drum specifications. No matter how sharp or how rounded the crest is, it has a radius, & that radius can be controlled & measured if time is taken to do so. The only exception to this is a totally flat crest. In essence, the smaller the radius, the more the head will sustain its movement when excited. As you move to a larger radius, this effectively puts the brakes on the head, right through to a full roundover (baseball bat edge) that cuts the head sustain pretty short.

If you look at how a head actually behaves in slow motion, the amplitude of the waves in the head, once excited, is very significant. So much so, that the edges of the head actually momentarily lift away from the inside edge of a big radius edge. This varies the head contact point across the peak of the radius, & in doing so, stifles continued resonance of the head. So, the smaller the radius, the less "braking" is applied to the head.

A flat crest works in the same way. Same physics apply, only there's a distinct step between reaction at low & high dynamics. Edges with a totally flat crest tend to have a very narrow crest. Typically no more than 1/8" across, but more usually less than 1/16". Imagine the same head dynamics, under low dynamic playing the head remains mostly in contact with the inner edge of the flat crest. Play harder, & the head starts to reciprocate between the inner & outer edge. This has the affect of promoting fairly long head sustain at low dynamics, but puts the brakes on at high dynamics. How pronounced the affect is depends on the depth of the flat.

The outer cut:This controls three basic elements:
1/ The static element of the amount of contact between the head & the shell.
2/ The orientation of the crest to the head.
3/ The head orientation directly prior to the crest.

So, breaking this down:
1/ The theory is that additional contact of the outer cut drives vibrations into the shell, & we've proved that to be the case in our A-B comparisons. This aspect matters more on some constructions than it does on others. For example, a very thick drum will gain almost nothing from this feature, as it's unable to respond to stimulus at such low dynamic levels. An exception to that is stave construction that uses the vertical grain structure to directly excite both the shell & the reso head. Equally, many less resonant forms gain little additional shell excitement from this feature. Highly resonant forms gain a noticeable additional level of excitement with full contact. The more rounded the outer cut, the more contact area is achieved. A straight cut 45 degree outer cut only contacts on the crest & the very outer edge of the angle intersection with the outer shell wall. A 30 degree outer cut achieves slightly more contact, but not much. Even the introduction of a gentle radius increases contact considerably.

2/ The outer cut depth dictates the crest position in relation to the shell thickness & ultimately the head itself. Moving the peak inward of the outside of the shell typically achieves seating the crest away from the formed area near the rim of the head, depending on make/model of head used. With some heads, this gets the peak away from that "crinkle" area thus promoting a more consistent contact.

3/ This matters to some degree, especially with respect to greater ease of tuning, but can also form part of the very high dynamic behaviour results on a very shallow & rounded crest.

Of course, in the case of a full roundover, all this information still applies, it's just that the divisions between the three edge elements merge into one.

The inner cut:least important of the three edge elements, or so you would think. The inner cut form can play a part in the sharpness of transition in a flat crest form, & that can dictate head sustain characteristics to some extent. The biggest affect however is how higher overtones are managed near the outer edge of the head. Getting that right, or even knowing where to start, is a bit of a black art TBH. Clearly, it's more important on a thicker shell where that inner cut is fairly generous. Only experimentation can dictate the best inner cut form, as it's affects vary widely from construction to construction.


As a footnote to all this, I cannot emphasise too strongly how big the affect of correctly specified & executed edges are. Outside of heads & tuning, it's the biggest every day affect on your drum's sound, & indeed, the biggest element that's beyond the control of most players to adjust. Standard double 45/30 degree edges are a most valid edge choice, but they are often specified because they're cheaper/faster to achieve in a production scenario, & control of that all important crest radius is more difficult in a fast finish environment. Ultimately, there's no substitute for taking time & multiple checking. A quick spin around the router & cusory hand sand or flat to finish will get you what you paid for. Even edges cut completely by CNC are a way away from guaranteed correct, for reasons I won't bore you all with now. Finally, edges are just one aspect of a drum's design, & must always be considered in the context of the overall instrument design.

I hope you find this basic edges breakdown of some use.

Andy
 

BabyBob

Silver Member
Andy, thank you for these wonderful threads, I've learned more than a few things from your threads, DW forum is really lucky to have someone whom has such wisdom aboard.
 

David Floegel

Silver Member
As a footnote to all this, I cannot emphasise too strongly how big the affect of correctly specified & executed edges are.
Indeed! I remember when I asked Sonor to cut new bearing edges to my Sonor Force 2001 drumset about 5 years ago. When the drums came back they sounded like another drumset! I would have never imagined that. Way more sustain and I felt like also the dynamic range has increased.


Andy, thank you for taking time to explain all this to us. I think these are "basics" that every drummer should know!
 

Magenta

Platinum Member
Andy, thank you for these wonderful threads, I've learned more than a few things from your threads, DW forum is really lucky to have someone whom has such wisdom aboard.
^^^ This - and it's all explained so clearly that even I, with my gnat-like attention span, can understand.

Fab stuff.
 

GruntersDad

Administrator - Mayor
When I suggested some weeks ago that you should write a book about drum construction, you replied that you didn't have time. What you have written, in your current three articles, is both entertaining and educational. Thanks for for finding the time. Johnny
 

Diet Kirk

Silver Member
Great stuff as usual!

So Andy, bearing edges are clearly a finely balanced art. How do you usually approach this? Do you construct a shell with the bearing edges in mind?, or do you construct a shell and then try a number of different bearing edge options to see how that specific shell sounds? Obviously given that you would have to keep shortening the drum to try too many options!

In addition have you ever put a different bearing edge on hi toms, low toms and a kick of the same kit?

I don't suppose you could also add your thoughts on snare beds too in relation to bearing edges?

I'm hearing a lot of good things about the new Evans 360 heads. What are your thoughts on these heads and the supposed increased interaction they provide with the bearing edge?
 

8Mile

Platinum Member
Andy, you're providing very valuable information here and I, for one, really appreciate it. There is so little information out there about this stuff -- there's probably more misinformation than accurate stuff -- and you're laying it out in a way that the lay/wo/man can understand.

I would refer people to these threads as a sort of drumming equivalent of Snopes. If someone makes some claim about how drum construction relates to the sound of the instrument, I would recommend fact-checking it here first.

These threads are a great example of why I find myself increasingly reluctant to speak authoritatively about anything; the more you learn, the more you realize how much you didn't know.

Thank you for taking the time to lay all of this stuff out for us lucky followers.
 

keep it simple

Platinum Member
I've learned more than a few things from your threads
That's great to hear :)

I think these are "basics" that every drummer should know!
Knowledge just helps you cut through the hype & make informed decisions. The danger is, knowledge in isolation can lead you down the wrong path. The skill is placing all these factors into the design context, knowing how those individual features come together, then testing to check results in the real world.

^^^ This - and it's all explained so clearly that even I, with my gnat-like attention span, can understand.

Fab stuff.
I'm glad that's clear info Mage. I desperately try to keep it simple, but without missing out key elements.

When I suggested some weeks ago that you should write a book about drum construction, you replied that you didn't have time. What you have written, in your current three articles, is both entertaining and educational. Thanks for for finding the time. Johnny
No problem Johnny. Putting up some simple threads is one thing, writing a book is on a whole different level. The detail required to do a "proper job" on it is immense. I've seen many drum design articles over the years. Frankly, very few of them are either that accurate or that useful.

These threads are a great example of why I find myself increasingly reluctant to speak authoritatively about anything; the more you learn, the more you realize how much you didn't know.
A bit like me in the technique sub forum then ;) Nah, seriously, the more I learn, the more I find there's a ton of stuff I don't understand. I suppose there's a cutoff point, but I haven't found it yet.

I look at it this way. We make drums. We tell people we make some of the best drums in the world (usual subjective caveats apply), so if we're to deliver that message with any credibility, we have to know our stuff. It's our job, & our customers expect nothing less.

It makes my skin crawl when I see videos of some marketing suit spouting crap about a feature he/she clearly knows very little about. It's the knowledge that the crap will be believed that gets under my skin the most.

Great stuff as usual!

So Andy, bearing edges are clearly a finely balanced art. How do you usually approach this? Do you construct a shell with the bearing edges in mind?, or do you construct a shell and then try a number of different bearing edge options to see how that specific shell sounds? Obviously given that you would have to keep shortening the drum to try too many options!

In addition have you ever put a different bearing edge on hi toms, low toms and a kick of the same kit?

I don't suppose you could also add your thoughts on snare beds too in relation to bearing edges?

I'm hearing a lot of good things about the new Evans 360 heads. What are your thoughts on these heads and the supposed increased interaction they provide with the bearing edge?
Ah, lots of questions. I'll be brief:

bearing edges are clearly a finely balanced art. In most respects, no. It's pretty simple stuff when you break it down. It's relating features & affects within the overall design concept that's the more difficult bit.

How do you usually approach this? Do you construct a shell with the bearing edges in mind?, or do you construct a shell and then try a number of different bearing edge options to see how that specific shell sounds? Obviously given that you would have to keep shortening the drum to try too many options!Neither, because our knowledge extends to every aspect of the design, we pretty much know what the outcome will be before we even make a test piece. Something that's completely blue sky thinking however, that's a bit more tricky. You've just got to swallow the cost & jump in with both feet. Pretty much why "design by shareholders" is always very tame :)

In addition have you ever put a different bearing edge on hi toms, low toms and a kick of the same kit?We do that routinely, as standard. Almost always different batter to reso edges too. There's rarely the same edge used twice on any part of our kits.

I don't suppose you could also add your thoughts on snare beds too in relation to bearing edges?Probably a bit too involved for this thread, plus, it's highly dependent on the drum's construction, & the balance of abilities dictated by the overall design.

I'm hearing a lot of good things about the new Evans 360 heads. What are your thoughts on these heads and the supposed increased interaction they provide with the bearing edge?In general, they do result in more head to edge contact, but that very much depends on the edge profile too. There's always exceptions. There's no doubt that the head edge form is superior to previous designs. Prior to 360, Evans provided us by far the most consistent heads. I don't expect that to change with 360. We've used over 100 360 heads to date, & not had a single issue.

TBH, outside of the smaller builders who've been optimising edge design for heads for years, it's only very recently that the major companies have caught on. Take an outside biased double 45 degree edge on a 6mm shell as a prime example. On a Remo head produced over the last 20 years or so, that's a pretty difficult marriage. At best, it's inviting inconsistency. I think there's a recent video available that amply explains how some companies have been getting it wrong for years. Not sure what it's called though ;)
 

Drumsinhisheart

Silver Member
Andy Foote, from Drum Maker, has gotten some bad press on the forum lately, but in fact, on his forum, back in the 90s, when the DIY boom hit, we had composed an online book about drum construction, as well as other forums.

http://pdgood.us/drumshed/

A tremendous amount of info there, as well as a parts guide and where to purchase stuff, etc., for those into it.

I saw an interesting interview with Ronn Dunnette a month or two ago, on Jared Falk's site. He took a non-descript tom and held it up and tapped it and asked the interviewer what he thought of the sound. The guy said it sounded great. Ronn took the head off and showed him the bearing edge - all beat up in various ways. His experience (and mine I have to say) is that the bearing edges really don't do as much to the sound of a drum as the industry likes to relate. It amounts to nuances often lost in full set play, and certainly in band play. Like Andy states here the head either vibrates more or less depending on edge contact, so sustain is what is effected the most, and impressions of 'attack.'

One thing I would mention about 45 degree outer cuts is that over time the head will change form and more closely 'marry' or mould to the outer cut. A head will more naturally and generally marry to a round over out of the box, but it will change shape under the tensions they are put under, in my experience.

I have heard drums with no bearing edges that sounded good, just very focused and sustain was lost. For players that like fat, dry sound, with twin ply heads or oil or whatever, They could find drums with little to no bearing edges right at home, but it's definitely a personal taste in sound.

Andy have you ever tried placing the edge totally outside, no inner cut? What did you think of the resulting attack/sustain/tone?
 

Smoke

Silver Member
If you're not going to write a book, how about an info-mercial on television?? :)

If nothing else, transcribe your tutorials to the Guru website - unless of course, that offers prospective buyers "too much information."
 

wsabol

Gold Member
Excellent stuff Andy,

Its easy to see how these are applied to toms, and to a certain extent kicks. But I'd like to know a bit of detail on how these theory/concepts apply specifically to snare drums. How are snare sensitivity, "crack" and "bite", duration of the note, and ring affected by bearing edge design, all other factors being the same?

For example, its conventional to attribute a nice sharp crack to sharp edges, but if I put baseball bat edges on my snare because I want to subdue batter head sustain, what exactly am I sacrificing in return? In my mind, rimshots are still going to be loud and crack regardless of the edge, it just might be a loss of ring and high overtones that give the impression of a softer, rounder sound..?.. but i could be wrong.. If conventional wisdom holds in this scenario, what design steps could you take to balance that loss of crackiness, maybe wood species and/or hoops?

I second Kirk, a thread on snare beds would be delightful. But maybe you could briefly delve into how snare reso edges are approached knowing that there is a snare bed. Does the fact that there is a snare bed limit types of edges that are generally appropriate to use? How are snare bed design and reso edge design related? Do deep snare beds usually work better with certain kinds of edges, for example?
 

keep it simple

Platinum Member
Very well put, Andy! Cheers
Thanks :)

Andy Foote, from Drum Maker, has gotten some bad press on the forum lately, but in fact, on his forum, back in the 90s, when the DIY boom hit, we had composed an online book about drum construction, as well as other forums.

http://pdgood.us/drumshed/

A tremendous amount of info there, as well as a parts guide and where to purchase stuff, etc., for those into it.

I saw an interesting interview with Ronn Dunnette a month or two ago, on Jared Falk's site. He took a non-descript tom and held it up and tapped it and asked the interviewer what he thought of the sound. The guy said it sounded great. Ronn took the head off and showed him the bearing edge - all beat up in various ways. His experience (and mine I have to say) is that the bearing edges really don't do as much to the sound of a drum as the industry likes to relate. It amounts to nuances often lost in full set play, and certainly in band play. Like Andy states here the head either vibrates more or less depending on edge contact, so sustain is what is effected the most, and impressions of 'attack.'

One thing I would mention about 45 degree outer cuts is that over time the head will change form and more closely 'marry' or mould to the outer cut. A head will more naturally and generally marry to a round over out of the box, but it will change shape under the tensions they are put under, in my experience.

I have heard drums with no bearing edges that sounded good, just very focused and sustain was lost. For players that like fat, dry sound, with twin ply heads or oil or whatever, They could find drums with little to no bearing edges right at home, but it's definitely a personal taste in sound.

Andy have you ever tried placing the edge totally outside, no inner cut? What did you think of the resulting attack/sustain/tone?
Andy's link is an excellent resource for the self builder. My thread is more of a bearing edge basics.

As for heads changing shape to more closely follow the edge form - I agree, but it depends on what head & what tension. At an extreme, an Evans hydraulic isn't going to change much on a bass drum.

Re: Ronn's interview. No disrespect to Ronn, but anyone who can tune a drum well, can make a drum with crappy edges sound acceptable. Depends on the listener too. Perhaps it would have more meaning if the same drum was presented side by side with good edges. Perhaps a different conclusion would be reached. I can't see Ronn coming out with a "shitty edges series" anytime soon ;)

Some real world truth in there though. If I took two Pearl Exports, one with crappy edges, one with good edges, & put them in a pub alongside a highly amplified rock band, would the audience tell the difference? Of course not, but that's not the application everyone references.

I can only reference our experiences, & be totally open about them. When you get into the better quality end of drum making, you soon find out that an accumulation of small improvements differentiates the good from the very good. If I was being cruel towards builders of higher end drums, I'd say the higher quality shells actually rely on those details to display their talents. I've said this before, & I'll say it again - just because something is built a certain way, or uses exotic woods, or has a certain bearing edge design, etc, etc, does not mean it will be a good drum. It's how elements are combined that dictate the result, & that's where the skill lies (& usually hard work + cost).

I haven't tries an edge devoid of inner cut, simply because of the type of shells we produce. I see absolutely no benefit, & on some constructions, I can see some big negatives.

If nothing else, transcribe your tutorials to the Guru website - unless of course, that offers prospective buyers "too much information."
Something I'm actually working on, is an advanced technical info page for the website. Takes time :(

Excellent stuff Andy,

Its easy to see how these are applied to toms, and to a certain extent kicks. But I'd like to know a bit of detail on how these theory/concepts apply specifically to snare drums. How are snare sensitivity, "crack" and "bite", duration of the note, and ring affected by snare bed design, all other factors being the same?

For example, its conventional to attribute a nice sharp crack to sharp edges, but if I put baseball bat edges on my snare because I want to subdue batter head sustain, what exactly am I sacrificing in return? If conventional wisdom holds in this scenario, what design steps could you take to balance that loss of crackiness, maybe wood species and/or hoops?

I second Kirk, a thread on snare beds would be delightful.
I could do a separate thread on snare drums. The requirements for snare drums differ from other drums, but equally, many elements are shared.

Specifically your question about "crack". A nice sharp crack isn't a product of sharp edges generally. It's more of a tuning, shell construction, timber species & hoop specification thing. Perfectly possible to get a high pitched biting crack from a snare drum with baseball bat edges.
 

Krampuz

Junior Member
Wow Andy!

That was really informative and makes you think of all the things you miss out when choosing a new drumkit or snare. I'm going to check out more of your threads for sure!

One thing that crossed my mind though was that I my self find videos to be much more interesting than reading. I'm sure I'm not alone when I say it would be freakin' awesome if you would put up some information videos, explaining and showing stuff like this. It makes the whole learning process much more fun and easy and also it's really nice to be able to hear the difference! Please consider it, I believe it would be very appreciated!
Once again, nice post, thank you!


Hampus
 

keep it simple

Platinum Member
Wow Andy!

That was really informative and makes you think of all the things you miss out when choosing a new drumkit or snare. I'm going to check out more of your threads for sure!

One thing that crossed my mind though was that I my self find videos to be much more interesting than reading. I'm sure I'm not alone when I say it would be freakin' awesome if you would put up some information videos, explaining and showing stuff like this. It makes the whole learning process much more fun and easy and also it's really nice to be able to hear the difference! Please consider it, I believe it would be very appreciated!
Once again, nice post, thank you!


Hampus
Thank you, I hope you find it useful.

Producing videos is both time consuming & potentially expensive, especially if you want to give a totally natural capture presentation. There's another angle too. I don't want to give away all our hard won information, that's why I keep things pretty general. I also try to make the info as widely applicable as possible.
 

larryace

"Uncle Larry"
I'm sure I'm not alone when I say it would be freakin' awesome if you would put up some information videos, explaining and showing stuff like this.
Hampus
I realize from your post count that you are a new member here, and you might not be aware of Andy's situation. With all due respect to you, Andy is one busy guy, I mean he is THE hardest working man I know. We are all very fortunate indeed to even have access to this information. He doesn't have to offer ANY of this stuff up. This is all hard won info that Andy is freely distributing. That really is MUCH more than any other builder does. I mean how much more do you want? Asking him to make videos...to me is kind of like someone offering food to a starving man and the starving man asks the food to be presented in a more appetizing manner. Screw that!

A little respect and appreciation would be in order here, not a request to make him work harder for you.
 

dwsabianguy

Senior Member
He took a non-descript tom and held it up and tapped it and asked the interviewer what he thought of the sound. The guy said it sounded great. Ronn took the head off and showed him the bearing edge - all beat up in various ways. His experience (and mine I have to say) is that the bearing edges really don't do as much to the sound of a drum as the industry likes to relate.
It seems as though Ronn proved an entirely different point: that any drum can be made to sound good. Obviously, this is true and it depends on the heads, your hands, and your ears. I don't think the ability to make a drum sound good automatically negates the effect of a bearing edge on a drum.
 

keep it simple

Platinum Member
I realize from your post count that you are a new member here, and you might not be aware of Andy's situation. With all due respect to you, Andy is one busy guy, I mean he is THE hardest working man I know. We are all very fortunate indeed to even have access to this information. He doesn't have to offer ANY of this stuff up. This is all hard won info that Andy is freely distributing. That really is MUCH more than any other builder does. I mean how much more do you want? Asking him to make videos...to me is kind of like someone offering food to a starving man and the starving man asks the food to be presented in a more appetizing manner. Screw that!

A little respect and appreciation would be in order here, not a request to make him work harder for you.
Larry, it's fine :) I can see why Krampuz would appreciate such a video presentation. It brings further evidence to the table, especially with a series of A-B comparisons that people can "touch & feel" as it were. Problem is, as you rightly point out, it's a lot of work. Can you imagine making all the drums necessary to isolate individual bearing edge features/ Phew.


It seems as though Ronn proved an entirely different point: that any drum can be made to sound good. Obviously, this is true and it depends on the heads, your hands, and your ears. I don't think the ability to make a drum sound good automatically negates the effect of a bearing edge on a drum.
Agreed.
 

Drumsinhisheart

Silver Member
It seems as though Ronn proved an entirely different point: that any drum can be made to sound good. Obviously, this is true and it depends on the heads, your hands, and your ears. I don't think the ability to make a drum sound good automatically negates the effect of a bearing edge on a drum.
Well, he did have other drums of his there to make the point: that he feels bearing edges are not as major a deal as is made of them. That was the question asked of him: the importance of different bearing edges to sound quality. He used the low level tom to make that point as far as his experience has gone. And he also fully disclosed that plywood drums are not his thing after making the titanium set. He hasn't seen that plywood shells are greatly effected by different edges as is so greatly discussed in the industry. It's more about head choices and how you mount things.
 

Red Menace

Platinum Member
Very interesting and informative read as usual Andy. Thank you for sharing it with us. So a couple of thoughts here...

It seems that the "perfect" edge does not exist. A one size fits all approach to drum design doesn't account for the individual characteristics of the drum and the sounds that the player will want to get from them. Sort of like some of the major companies that are trying to sell one edge as the end all *cough* Mapex! *cough*. A dual 45 deg. seems to be the standard. I really do wonder why that is. Is this a feeble attempt to get a brighter cutting sound?

As for Dunnett's experiment, I'll bet that same drum would sound much better with some nice clean edges. Hell, with good heads and some time tuning I would make just about any ratty drum sound good. That doesn't negate the effect of edges on the overall sound.
 
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