Strongest Edge Joint???

[Rob S]

My first post...

 

I have searched everywhere and can’t find the answer to my question.  Need some advice please.

 

I build custom equipment rigs for professional electric guitar players. 

Trying to improve sound quality, I want to experiment with building speaker cabinets and amplifier combo cabinets with solid wood instead of plywood type products.  High quality Spruce or Pine.

 

Some of the cabinets will need to be 16 to 24 inches deep.  This means I need to join boards at the edge.   I know there are many techniques and plenty of info for edge joinery.  My concern is the joints need to be mega strong.  These speaker cabinets and amplifiers get bounced around pretty hard. Any pro music gear has to be virtually indestructible.  

 

The ½” boards will be speaker baffles for up to 18” speakers.  5/8^” is for speaker or amplifier cabinets.  Don’t want to go to ¾” because of weight.   

 

What is the strongest way to edge join ½” or 5/8^” boards?  

 

I am willing to invest in the tools needed if I do not already have them.

 

Sorry for the long lead in to a short question. 

 

Thanks in advance,

 

Rob

[Immortan D]

Like Mike said, wood glue is the best option. Since you're going to use solid wood, you may also want to buy a jointer machine or a router fence with jointing capabilities. And also lots of clamps!

 

Dominoes may not add strength to the joint, but they will make alignment easier when dealing with long pieces.

[dwacker]

The strongest joint is going to be one that maximizes surface area. That said in order for there to be any benefit you have to be equipped to cut the joinery cleanly and tight fitting. A multi  V groove is going to be many times stronger than a jointed joint. But again you have to be equipped to create the joint cleanly, not gunna happen on a router table.

[wtnhighlander]

Beware that using solid wood for speaker cabinets will result in speakers that sound different, even though they are otherwise identical. Speaker cabinets are made of particle board for the lack of resonance as much as for lower cost.

[drzaius]

Plywood will be so much tougher than solid.  I can't imagine a 1/2" or 3/4" solid pine or spruce cabinet standing up to much bouncing around.

[Oceandragon]

Wouldnt the music, vibrate the glue joints to the point of Fracture.

Why not glue box joints with screws , almost seems like too much to ask for from 5/8 soft wood material for the abuse you said its going to take. If its gonna get pushed around and abused the shock at the joints is going to pop the glue line (the box joints would help) and with a jig easily repeatable right from a production point of view, what type of glue will you be using as some handle shock better than others.

Maybe prototype one and see how it handles the abuse if time permits, then adjust your build as needed.

[Janello]

====> not gunna happen on a router table.

 

This a typo? I use a reverse joint glue bit on my router table with no issues.

[dwacker]

====> not gunna happen on a router table.

 

This a typo? I use a reverse joint glue bit on my router table with no issues.

 

A reverse glue joint is really not much more than a tongue and groove the diameter is to small to eliminate scalloping and burnishing. If you cut between the fence and bit with a power feeder you could do ok but not nearly as well as just a jointer. They are a great alignment aid but for edge gluing the surface has to be nearly perfect to be of any real benefit. This has was beat to death back in the 50's and 60's and its been proven that anything beyond a standard jointed edge that is not cut nearly perfect is actually provides less strength. I think it was the usfc study of wood glues that stated a tongue and groove joint was no benefit because it could not be cut at tight enough tolerances to do anything more than proved an alignment aid. Today we use large diameter v groovers that do well but even those have to be used between the fence and cutter head to get the expected results.

[Beechwood Chip]

A jointed long grain to long grain glue joint, with modern glue and good clamping, cauls, etc, will be stronger than the wood itself.  So, the wood will fail before the glue joint does.  So, if that's not strong enough, we need to use stronger wood, not worry about making a stronger joint.

 

I like the idea of using plywood, and then you don't need to glue up a wide panel.  Problem solved.  It will be stronger against bending forces, because it won't crack along the grain.

 

If you have your heart set on hardwood, then you might want to use something stronger (and heavier) than spruce or pine.  But I think plywood is the way to go.  Or maybe particle board as Highlander said, for the acoustic properties.

[Madkrafter]

I agree with the others that a proper edge joint will be plenty strong. Solid wood can create a different kind of sound for music cabinets. Just look at the lore of old Fender Tweed and Bassman cabinets. The better question is how strong are your corner joints. They will take most of the abuse. Finger joints are typical because of the strong mechanical joint it creates as well as the abundance of glue surface to add to the strength. 

 

I would watch how thin you go. Pine can be pretty light weight. MDF is favored because of its dampening abilities as well as economics but comes at a cost with the weight. You also have to consider whether you are building open or closed back. If closed back is used, the back panel will play into the sonic properties of the cabinet as well as the front baffle.

 

You can go all out with nice hardwood cabinets  and charge a premium. I think that is usually done more for the bling with combos, heads and matching speaker cabs. That said, I have wanted to rebuild my Groove Tubes Soul-O 75 combo with some nice hardwood!

[Rob S]

Wow!  Thanks for all the input.  I am glad I asked.

 

I will say I have built hundreds if not thousands of speaker enclosures over the years.  Some plywood and some MDF.  All wood has resonant and tonal properties.  i.e., guitars, pianos, violins and speaker cabinets.  I know that many builders have used many types of wood for their different tonal properties.  

I am wanting to experiment with various woods to learn how they sound in specific situations.  I may find that there is no appreciable difference but based on experiments using solid woods on smaller cabinets the sound difference is appreciable.  

 

wtnhighlander and Madkrafter are right about the sound properties and no two sounding the same.  But that is ok. I can tweak other aspects of the components to gain consistency of sound.  Like I said in the original post I build custom rigs.  Very custom.

 

 

Madkrafter - I have worked on hundreds of old fender amps.  I own a couple of dozen.  One of the things Leo Fender was notorious for was building amps with the most cost effective materials possible.  So the older combos where made of pine in most cases.

 

I have always used through dovetails for corner joints.  I have tried many other things and the dovetails have held up best.  

 

OK, with all that said.  Now I need some direction on instructional articles, videos or books that will help me understand the tools and techniques necessary to get the joints you all described.  And maybe some input on glue.  I have always used the basic tight bond wood glue. 

 

Thanks again!

[Madkrafter]

No problem Rob!

 

Well it sounds like you have a heck of a lot more experience building speaker cabinets than me  . It sounds like what you have done in the past will continue to work just fine. If you're doing through dovetails, that would work great for solid pine as well. Box joints are just another technique that will give you similar strength but not even as good of a mechanical joint as dovetails. No need to start down a different path if you've got a good one already.

 

Glues today are great. Titebond will be fine. Titebond III gives you a little more open time, lower working temperature and a little more strength (4,000 psi vs. 3,600 psi). In reality, I'm not sure how big of a difference 400 psi is (unless you're talking about some rough roadies!)

[Coop]

Wasn't the original question was about edge jointing multiple boards to make wider ones. Wouldn't box joints/ finger joints be a bad idea to accomplish this. One, that's a lot of cutting and two, there's no grain support when you cut notches on the edge of a board. On the end of a board, I agree.

[ponderingturtle]

I agree with the others that a proper edge joint will be plenty strong. Solid wood can create a different kind of sound for music cabinets. Just look at the lore of old Fender Tweed and Bassman cabinets. The better question is how strong are your corner joints. They will take most of the abuse. Finger joints are typical because of the strong mechanical joint it creates as well as the abundance of glue surface to add to the strength. 

 

I would watch how thin you go. Pine can be pretty light weight. MDF is favored because of its dampening abilities as well as economics but comes at a cost with the weight. You also have to consider whether you are building open or closed back. If closed back is used, the back panel will play into the sonic properties of the cabinet as well as the front baffle.

 

You can go all out with nice hardwood cabinets  and charge a premium. I think that is usually done more for the bling with combos, heads and matching speaker cabs. That said, I have wanted to rebuild my Groove Tubes Soul-O 75 combo with some nice hardwood!

 

The problem with some of this is that you are getting into areas where people can fool themselves into hearing things that are not there or they can not be shown to hear in blinded testing.  Look at the testing that showed people couldn't reliably tell the difference between a $1000 speaker wire and a wire coat hanger between the amplifier and the speaker.

[Tpt life]

The problem with some of this is that you are getting into areas where people can fool themselves into hearing things that are not there or they can not be shown to hear in blinded testing. Look at the testing that showed people couldn't reliably tell the difference between a $1000 speaker wire and a wire coat hanger between the amplifier and the speaker.

That ignores interference and longetivity. The coat hanger rusts and picks up lots of radio stations

[ponderingturtle]

That ignores interference and longetivity. The coat hanger rusts and picks up lots of radio stations

And that isn't what was being tested.  Rather it was a direct testing of the claims that spending more than $1000 on a wire in your stereo system will lead to an improvement in audio quality that is decernable to the human ear.

 

The point was that the claims made by supporters of the cables where bunk not that they are a terribly practical method of running such signals.  Though many coat hangers are now aluminum so they at least wouldn't rust.

[Rob S]

And that isn't what was being tested.  Rather it was a direct testing of the claims that spending more than $1000 on a wire in your stereo system will lead to an improvement in audio quality that is decernable to the human ear.

 

The point was that the claims made by supporters of the cables where bunk not that they are a terribly practical method of running such signals.  Though many coat hangers are now aluminum so they at least wouldn't rust.

Pondering

I appreciate what you are saying. I have a PhD in Physics from NJIT and I am a PE.  I can absolutely tell you that what you have read about the human ear and a discernible difference in audio quality is total BS written by those who either can't afford or are not willing willing to spend money on high quality audio.    The people trying to debunk cables, speakers or any other high end audio components are only trying to do so because they hate that someone else is making money selling quality products and they are not. Or maybe they have mommy issues.  

 

To a professional musician, the difference in various equipment is very appreciable.  The human ear is capable of discerning very small differences in audio.  I have studied sound wave propagation and analog audio circuits for 20+ years.  I have worked with the best in the business.  I promise you my clients like Alex  Lifeson, the late Jonny Winter, Trey Anistasio, Buddy Guy, Richie Sambora, David Glimour, Jeff Beck, Brian May and The Edge just to start the list, will all tell you that there are a number of things that can change the sound of a guitar and all those small things add up.  Cables, Wood, Capacitors, Tubes, Speakers and the list go on and on and on.  I hate to bust your bubble. Because this is a wood working forum and not a electric guitar forum I will stop now.  This is all I will have to say on the matter.

 

To all of you who so graciously answered my questions, thank you very much.  You have been very helpful.  This is a great forum. 

 

I also apologize for the lousy grammar.  I jammed this out on my iPhone in about two minutes.  

 

Very best regards,

 

Rob

[ResidentEvil]

I have no idea what the effect of this may be, but I was thinking about solid hardwood vs your engineered materials (ply, MDF, particle board, etc).

 

One thing that could throw a wrench into your builds is that, at least IMO, each board may vary a bit in density/figure/imprefections/etc.  I would think that you could build two identical speaker cabinets out of the same type of hardwood with the same speaker components, and get two different sounds.  Just thinking about how I've picked up two very similar sized pieces of the same species of wood and they have felt significantly different in weight.  Then you add in knots, small cracks, etc...I would think that all these things could cause the acoustic properties of each cabinet to vary quite a bit.

 

I would think that this could lead to a lot of time spent selecting lumber, matching density/imperfections/etc, and then fine tuning once everything is assembled.  But then again, you are the expert at this stuff and it sounds like you are going for a very custom application with each unit.

 

I'd be interested to hear your thoughts on how well it worked out after you've had a chance to build several units and have worked through the kinks to see if it does make it more difficult or if my thoughts are completely off base.  Good luck and check back once you have put a few together.

[Janello]

Pondering

I appreciate what you are saying. I have a PhD in Physics from NJIT and I am a PE.  I can absolutely tell you that what you have read about the human ear and a discernible difference in audio quality is total BS written by those who either can't afford or are not willing willing to spend money on high quality audio.    The people trying to debunk cables, speakers or any other high end audio components are only trying to do so because they hate that someone else is making money selling quality products and they are not. Or maybe they have mommy issues.  

 

To a professional musician, the difference in various equipment is very appreciable.  The human ear is capable of discerning very small differences in audio.  I have studied sound wave propagation and analog audio circuits for 20+ years.  I have worked with the best in the business.  I promise you my clients like Alex  Lifeson, the late Jonny Winter, Trey Anistasio, Buddy Guy, Richie Sambora, David Glimour, Jeff Beck, Brian May and The Edge just to start the list, will all tell you that there are a number of things that can change the sound of a guitar and all those small things add up.  Cables, Wood, Capacitors, Tubes, Speakers and the list go on and on and on.  I hate to bust your bubble. Because this is a wood working forum and not a electric guitar forum I will stop now.  This is all I will have to say on the matter.

 

To all of you who so graciously answered my questions, thank you very much.  You have been very helpful.  This is a great forum. 

 

I also apologize for the lousy grammar.  I jammed this out on my iPhone in about two minutes.  

 

Very best regards,

 

Rob

 

I'll meet you half way on this. Sure for the likes of David Gilmour and Jeff Beck (where money is no object) picking up a small amount of audio quality here and there adds up. For a Garage band playing in a local club that has 100 drunk folks (half of them neighbors and friends) no one would know the difference if it hit them in the head like a iron skillet.

[ponderingturtle]

Pondering

I appreciate what you are saying. I have a PhD in Physics from NJIT and I am a PE. I can absolutely tell you that what you have read about the human ear and a discernible difference in audio quality is total BS written by those who either can't afford or are not willing willing to spend money on high quality audio. The people trying to debunk cables, speakers or any other high end audio components are only trying to do so because they hate that someone else is making money selling quality products and they are not. Or maybe they have mommy issues.

To a professional musician, the difference in various equipment is very appreciable. The human ear is capable of discerning very small differences in audio. I have studied sound wave propagation and analog audio circuits for 20+ years. I have worked with the best in the business. I promise you my clients like Alex Lifeson, the late Jonny Winter, Trey Anistasio, Buddy Guy, Richie Sambora, David Glimour, Jeff Beck, Brian May and The Edge just to start the list, will all tell you that there are a number of things that can change the sound of a guitar and all those small things add up. Cables, Wood, Capacitors, Tubes, Speakers and the list go on and on and on. I hate to bust your bubble. Because this is a wood working forum and not a electric guitar forum I will stop now. This is all I will have to say on the matter.

To all of you who so graciously answered my questions, thank you very much. You have been very helpful. This is a great forum.

I also apologize for the lousy grammar. I jammed this out on my iPhone in about two minutes.

Very best regards,

Rob

So you think that putting $5000 cables in a home stereo makes a difference? Then again they was my favorite one from a few years ago the $3000 blue ray player was of course just a $500 one in a fancy case.

The problem is that physics and engineering does not have a good background at how to accommodate for biases in personal perception. It is easy to get people to have objectively different experiences(as measured by FMRI) by what they hear about things like being told different prices for a wine sample.

This is a big part of why it is very easy for deceptive individuals to fool scientists. Look into James Randi's work at helping scientists recognising such deception.

You need to do double blind testing, and yes some of these do matter and some don't. Or do you think that sales of CD reminders made sense?

Somethings certainly do matter, but you can't trust your own ears. You have to not know which or personal bias will be a factor. Or are you next going to argue chemistry is wrong because of homeopathic provings done on animals showing beneficial effects of things diluted by a factor of 1 in 10^200?

[RPCV_Woodworker]

So you think that putting $5000 cables in a home stereo makes a difference? Then again they was my favorite one from a few years ago the $3000 blue ray player was of course just a $500 one in a fancy case.

The problem is that physics and engineering does not have a good background at how to accommodate for biases in personal perception. It is easy to get people to have objectively different experiences(as measured by FMRI) by what they hear about things like being told different prices for a wine sample.

This is a big part of why it is very easy for deceptive individuals to fool scientists. Look into James Randi's work at helping scientists recognising such deception.

You need to do double blind testing, and yes some of these do matter and some don't. Or do you think that sales of CD reminders made sense?

Somethings certainly do matter, but you can't trust your own ears. You have to not know which or personal bias will be a factor. Or are you next going to argue chemistry is wrong because of homeopathic provings done on animals showing beneficial effects of things diluted by a factor of 1 in 10^200?

 

I think you actually have made his point for him:

The physics of sound being fully measurable and quantifiable, one can scientifically prove that the higher grade cables and speakers produce sound quality that is higher.  The mechanics of the human ear and neurotransmitters also being known, it can then be shown that the increased range of sound is, in fact, discernible to human beings. 

 

The use of double-blind testing to determine user bias and FMRI technology to view real-time brain stimulation is, on the other hand, closer to the level of "homeopathic provings."  The fact that the general population does not appear to be able to register and assess the changes in quality of different objects does negate or invalidate scientifically measurable evidence that there is in fact a difference.  

 

To return to our chosen medium of wood, denial of improvement in sound quality generated by improved conductive materials is analogous to denial of janka hardness ratings because "it all feels hard when I hit it," despite the fact that janka hardness uses a standard testing procedure and fixed scale.

[wtnhighlander]

This is beginning to sound like the "better curve" thread from a while back.

I think part of the issue is a lack of definition and context for the term "better" especially when used for marketing.

What sounds " better" to ME may sound like utter crap to YOU, and vice-versa. Personally, I put more faith in marketing that demonstrates specifically how a product affects the end result. "Our brand of speaker wire is worth $100/ft, because it passes frequencies between 20 and 20,000 hz with less than .005 db attenuation" makes more sense to me. "It sounds better" has a large degree of subjectivity from person to person.

[Eric.]

Just a reminder to keep things friendly...all opinions are to be respected, even if they're wrong. LOL

 

I think it's a matter of diminishing returns, just like so many other endeavors regarding ratios of quality and value.  While I can't say that I was aware that $5,000 cables for home stereos even existed...and I do hope that's an exaggeration...I think cables costing half of that ridiculous number would surely produce a sound indiscernible to the human ear.  In fact, without personal experience to back it up, I would assume that $100 cables would produce a similar result, depending on the quality of the overall system those wires are connecting.

 

Sound quality in audio systems is only as good as its weakest link, so if you connect $5,000 cables to a system you bought at Best Buy...even their most expensive system...chances are you won't be able to tell the difference, because the system itself is not capable of relaying the improvement.  You reach a point of diminished returns with even minor upgrades.  But once you start fiddling with high-end systems, small changes can make a significant and discernible difference because the system is not holding the upgrade back.

 

All I know is that my McIntosh system is far superior in sound quality to the Sony receiver and Klipsch speakers I have in my shop...both systems contain wires and components...why is one so much better than the other?  You do eventually reach a point where the difference can only be perceived by computers...where exactly that point is depends on the ear of the listener until you go beyond the physical limitations of human observation.  But David Gilmore will presumably be able to detect more nuanced changes in sound than someone like, let's say...me.

[Rapid Roger]

What was the question again?

 

Rog

[ponderingturtle]

I think you actually have made his point for him:

The physics of sound being fully measurable and quantifiable, one can scientifically prove that the higher grade cables and speakers produce sound quality that is higher.  The mechanics of the human ear and neurotransmitters also being known, it can then be shown that the increased range of sound is, in fact, discernible to human beings. 

 

The use of double-blind testing to determine user bias and FMRI technology to view real-time brain stimulation is, on the other hand, closer to the level of "homeopathic provings."  The fact that the general population does not appear to be able to register and assess the changes in quality of different objects does negate or invalidate scientifically measurable evidence that there is in fact a difference.  

 

To return to our chosen medium of wood, denial of improvement in sound quality generated by improved conductive materials is analogous to denial of janka hardness ratings because "it all feels hard when I hit it," despite the fact that janka hardness uses a standard testing procedure and fixed scale.

So you think there really is a benefit to these $1000+ power cables?

 

http://www.lessloss.com/dfpc-series-p-213.html#sig

 

If so would you consider them for your tablesaw?

 

The problem is that we can measure differences that we can not discern.  So just because there is a measurable difference between two things and you hear a difference when you know it is there doesn't mean you can tell the difference in double blind testing.  The mind is very capable of convincing people of things that they want to believe, like that they are special enough to hear the difference in a $1000+ power cable makes instead of having such poor quality ears that you think a $5 one is just as good.  That is why measuring a difference isn't enough you need double blind testing.

 

The point about homeopathy was that it was with animals, so the animal wasn't getting better, but the tests showed a difference because the placebo effect works on those administering tests as well as patients.  They see an improvement that doesn't exist because they want to.  And if you bought a $1000+ wire you want to think you didn't just waste a lot of money.  So you will hear the difference.

 

That is not to say none of these things ever matter, it is that you need rigorous testing protocols to get rid of personal bias's to be certain it is not your bias talking and as such a real difference.

 

And being a PE or a Phd, doesn't matter, as I am not impressed by either. I spend way to much time at work telling our PE I work with how to do things like add vectors.  And expertese in some area of physics does not lead to understanding the psychological factors in testing perception.