Continuum Build

[MrBoat]

Nothing really to see yet but I did get the crossovers welded up. First let me say, I am not a fan of using MDF for crossover boards. I remember going thru this on the Classix2 build and swearing to use something else the 'next' time. I have a piece of micarta here somewhere I made out of about 6 layers of canvas that would have certainly drilled better than this stuff does and it would hold screws if needed and hot melt glue would likely stick to it much better.

The other thing that seems somewhat layout-less is, point-to-point wiring between the components. I'm not even sure how important this is with something like a crossover circuit. If I were to use patch wires between the components, in which to neaten up the build or leave some future service capability on the blind side where all the soldering is done, I start wondering if these minute, additional resistances add up to make a difference when looking at the values of these parts. Especially when you see something with a value plus a .1 or 2 and if that matters when you think about acceptable +/- tolerances being forgiving enough or not.

At any rate, it's probably a ridiculous, OCD thing of little concern, especially considering these things will not be seen. I just think about the poor schmuck that inherits these things in the future and needs to work on them and finding the handiwork of some. . . .hack.

Perhaps I should write; "Sorry dude" with a little smiley face on the back.

Anyway, in spite of holiday procrastinations being what they are, it's a start at least and it's always the part I procrastinate about the most.

Rough layout of the parts.

Parts wired thru the board and zip tied etc with the leads kind of heading where they need to go.

Then it's just a matter of getting some good mechanical connections and soldering (the easy part) everything. I did test them with the drivers to see if I got sound on low volume before I soldered everything at least and it's a go. I didn't push it, but you could tell by the sound that the drivers wanted to play, even outside of the nonexistent cabinets. No static, buzzes or anything like that.

I did leave all of the leads their original length and just looped them a bit where possible so at least some of the more expensive parts can be reworked if need be. I also got rid of the electrical tape and stickers on the inductors and just wrote the values on the ends with a sharpie. Not a fan of how gooey electrical tape gets over time. I just tightened up the windings after they were through the holes and let the hot melt hold them tight.

 

[jororaitchev]

The volume installation is preferred by the HI-End maniacs, but there is a fundamental moment - the incorrect arrangement of the elements leads to excitation between the elements .
I do not know what тhe type of is the circuitry of this filter is, but the inductances / located in this way / may cause you a problem.
My favorite product is "Solder tag strip 28 gold plated tags"- Jantzen Audio.
For the base of the filter I use plywood- 10mm.

 

[MrBoat]

The volume installation is preferred by the HI-End maniacs, but there is a fundamental moment - the incorrect arrangement of the elements leads to excitation between the elements .
I do not know what тhe type of is the circuitry of this filter is, but the inductances / located in this way / may cause you a problem.
My favorite product is "Solder tag strip 28 gold plated tags"- Jantzen Audio.
For the base of the filter I use plywood- 10mm.

This is the recommended arrangement. As long as the inductors are not arranged the same direction next to each other is the popular approach. Then again, I saw a test where they tried it that way and there was no significant, measurable difference.

Yes, plywood would have been better. The only reason I used this was it was already to size and I had all the parts out and it was too late to make sawdust. Next time, I will remember ahead of time. I was happy to get these completed. The little cabinets are the fun part.

 

[TheWarrior]

Use peg board for crossovers, you can zip tie more easily as the holes are already there.

 

[MrBoat]

Use peg board for crossovers, you can zip tie more easily as the holes are already there.

Warrior. . . .just say no, to any wood pulp or sawdust byproduct construction materials.

Masonite, tempered, or otherwise is something else I'm not fond of. lol

I remember all the back covers of electronic appliances being made of that. I'm half kidding with being so picky.

I have a bunch of scraps of 9mm meranti marine plywood that's 7 plies and dead flat that's pretty nice and that is pretty much useless for anything else. I end up using it for terminal plates and other small bits.

 

[MrBoat]

I did get the cabinet sides cut out today at work. It's a slide week this week as it was optional to take the week off so I used the shop's unisaw instead of dragging mine out. I'll router the rabbets out before work tomorrow. I'm not going to cut the front and back panels until after they're glued together. I have some 13 ply, 18mm BS1088 meranti plywood leftover from the boat build I may use for the fronts and backs. "BS1088" is the highest Lloyds certification for marine plywood. It's pretty nice stuff. Thinking of using plywood for the fronts and backs because they are removable, or the fronts are at least and are held on with screws. If they sound as good as they are reported to, I will do something nice to them after I hear them.

Side panels are 1/8" longer than spec. I will rabbet the ends 1/16th strong so there is some to sand flush. Would rather sand the edges flush instead of the panel faces. I do have flush trim bits but MDF sands easier than setting up the router. I will give them a seal coat of thinned epoxy so it doesn't soak up contact cement if I end up veneering them.

 

[TheWarrior]

Warrior. . . .just say no, to any wood pulp or sawdust byproduct construction materials.

Masonite, tempered, or otherwise is something else I'm not fond of. lol

I remember all the back covers of electronic appliances being made of that. I'm half kidding with being so picky.

I have a bunch of scraps of 9mm meranti marine plywood that's 7 plies and dead flat that's pretty nice and that is pretty much useless for anything else. I end up using it for terminal plates and other small bits.

I wasn't around for those days, so I do not know the horrors of old adhesives. The modern ones are incredible. Don't get me wrong, I hate working with MDF, but sometimes it's the best solution!

 

[MrBoat]

I wasn't around for those days, so I do not know the horrors of old adhesives. The modern ones are incredible. Don't get me wrong, I hate working with MDF, but sometimes it's the best solution!

I'll forget about it soon enough. I already have, really. I planned not to use it for the cabinets, either, but in the end, the rabbet joints won and the fact I had leftover pieces to use. It veneers well and being that speakers generally have to just sit somewhere ends up being one of those things that most people could care less of what it's really made of, as long as it just doesn't fall apart looking at it.

 

[slipperybidness]

I wasn't around for those days, so I do not know the horrors of old adhesives. The modern ones are incredible. Don't get me wrong, I hate working with MDF, but sometimes it's the best solution!

Agreed, modern adhesives, epoxies, and even canned spray paints are miles ahead of where we were even just 20 years ago!

I have analyzed many of these materials over the years, mainly looking at outgassing ions and organics, and giving the pass/fail for using these materials in a Class 1 cleanroom.

In general, 2-part materials tend to be superior in our applications.

As far as modern RTV that is non-corrosive, I have used this stuff for the last several years, and it is an excellent product! I originally bought it to give some mechanical support for components on DIY PCBs, but I have since used it in many other applications too.

https://www.amazon.com/MG-Chemicals...id=1499362316&sr=8-1&keywords=electronics+rtv

Only a chemist could get excited about paints, adhesives, epoxies, detergents, surfactants, etc! I once saw a job posting for a "paint formulation chemist". You just know that part of the job description had to be "watching paint dry"

 

[MrBoat]

Agreed, modern adhesives, epoxies, and even canned spray paints are miles ahead of where we were even just 20 years ago!

I have analyzed many of these materials over the years, mainly looking at outgassing ions and organics, and giving the pass/fail for using these materials in a Class 1 cleanroom.

In general, 2-part materials tend to be superior in our applications.

As far as modern RTV that is non-corrosive, I have used this stuff for the last several years, and it is an excellent product! I originally bought it to give some mechanical support for components on DIY PCBs, but I have since used it in many other applications too.

https://www.amazon.com/MG-Chemicals...id=1499362316&sr=8-1&keywords=electronics+rtv

Only a chemist could get excited about paints, adhesives, epoxies, detergents, surfactants, etc! I once saw a job posting for a "paint formulation chemist". You just know that part of the job description had to be "watching paint dry"

I actually knew a career chemical engineer, who has since passed, but really gave me a lot of insight into 2 part epoxies and LPUs and other catalyzed systems. Much of what I actually got to prove in use, in the composites and marine trades on and off over the years.

I rate epoxies, or even poly/vinyl ester as one of the best inventions of the 20th century. It typically appears in my build threads with speaker projects in some fashion. Even the modern, moisture cured urethanes are pretty awesome. PL's siding, window and door sealant ends up working as a superior adhesive for some rather extreme exterior conditions, as is the case with 3m's 5200.

Still, even some of the old technology such as shellac, or lacquer, manage to hold their own this far down the road.

 

[slipperybidness]

I actually knew a career chemical engineer, who has since passed, but really gave me a lot of insight into 2 part epoxies and LPUs and other catalyzed systems. Much of what I actually got to prove in use, in the composites and marine trades on and off over the years.

I rate epoxies, or even poly/vinyl ester as one of the best inventions of the 20th century. It typically appears in my build threads with speaker projects in some fashion. Even the modern, moisture cured urethanes are pretty awesome. PL's siding, window and door sealant ends up working as a superior adhesive for some rather extreme exterior conditions, as is the case with 3m's 5200.

Still, even some of the old technology such as shellac, or lacquer, manage to hold their own this far down the road.

Here is a specific product, NSR150, that is one of the best epoxies that I have ever tested from the standpoint of out-gassing and causing contamination. The guys that wanted to use it in the factory really like the stuff because they say that you can even apply it under water, then activate it, and it will permanently stop leaks! And, you activate with a special flashlight too. So, 1-part chemical and the 2nd part is an intense light. Pretty dang nifty and high-tech stuff.

http://www.northsearesins.com/images/NSR-150_Data_Sheet_Rev_2.1.pdf

 

[MrBoat]

Here is a specific product, NSR150, that is one of the best epoxies that I have ever tested from the standpoint of out-gassing and causing contamination. The guys that wanted to use it in the factory really like the stuff because they say that you can even apply it under water, then activate it, and it will permanently stop leaks! And, you activate with a special flashlight too. So, 1-part chemical and the 2nd part is an intense light. Pretty dang nifty and high-tech stuff.

http://www.northsearesins.com/images/NSR-150_Data_Sheet_Rev_2.1.pdf

These are all products that have been needed and is some of the most exciting technology to behold in industry. They end up solving a multitude of old problems. Solutions that were unfathomable just a decade ago. The other thing I like about recent approaches to these types of technology is that it's not just available to specialized industry. Take super-adhesives that were developed primarily for aviation industry. We are able to get our hands on many of these things now just for them being able to produce a non-caustic formulations, or those that become inert once cured at least, which is the case with many of the newer epoxies.

One of the only real issues with the older epoxy formulations is it's long term effects to those with sensitivity to amine used in the hardeners. So great care had to be (and still should be, regardless) taken with exposure.

I will check out that epoxy you mentioned.

 

[TheWarrior]

Agreed, modern adhesives, epoxies, and even canned spray paints are miles ahead of where we were even just 20 years ago!

I have analyzed many of these materials over the years, mainly looking at outgassing ions and organics, and giving the pass/fail for using these materials in a Class 1 cleanroom.

In general, 2-part materials tend to be superior in our applications.

As far as modern RTV that is non-corrosive, I have used this stuff for the last several years, and it is an excellent product! I originally bought it to give some mechanical support for components on DIY PCBs, but I have since used it in many other applications too.

https://www.amazon.com/MG-Chemicals...id=1499362316&sr=8-1&keywords=electronics+rtv

Only a chemist could get excited about paints, adhesives, epoxies, detergents, surfactants, etc! I once saw a job posting for a "paint formulation chemist". You just know that part of the job description had to be "watching paint dry"

I can definitely relate to being excited about details most people are not. And as a woodworker, I reap the benefits of your work! Now I'm just trying to take box building (cabinetry/furniture) and make them sound good too!

 

[MrBoat]

I did manage to get the cases assembled being I was right there after rabbeting the edges. I put some parchment paper down on the router table which is dead flat, in which to flush all the faces. I didn't want to leave any sanding on the edges in the event I want to veneer them to simulate solid wood. If you use rotary cut veneer on the flats, and quarter sawn on the edges, it becomes pretty much indistinguishable from solid wood if you fake the miters on the leading edge. Overlapping the veneers past the miters, and then double cutting them with a new blade on a utility knife makes for some tidy joints that all but get lost under subsequent finish coats.

I am going to seal these inside and out with epoxy resin thinned with denatured alcohol.

 

[MrBoat]

I put about 4 coats (from the same mix) of alcohol thinned epoxy on the boxes so that I don't have to use 2 coats of contact cement if I veneer these. Usually, the first coat of contact cement gets absorbed and you have to let that dry before the actual adhesion coat or you could end up with a glue starved lamination that could either bubble, or lift on the edges. This way here I can apply a uniform coat of cement and it will cure evenly with just the right amount for a consistent bond. Also, without those stringy rubber bands that happen when you try to work contact cement that is flashing too quickly in spots.

Not such a big deal on such small boxes as these, but it's just more of a personal preference thing. I'll hit them with the sander to key it a bit and it's still just porous enough for the contact cement to get a good bite, otherwise. If I don't end up veneering them, this is a great primer coat for paint for the same reasons either way.

 

[TheWarrior]

I put about 4 coats (from the same mix) of alcohol thinned epoxy on the boxes so that I don't have to use 2 coats of contact cement if I veneer these. Usually, the first coat of contact cement gets absorbed and you have to let that dry before the actual adhesion coat or you could end up with a glue starved lamination that could either bubble, or lift on the edges. This way here I can apply a uniform coat of cement and it will cure evenly with just the right amount for a consistent bond. Also, without those stringy rubber bands that happen when you try to work contact cement that is flashing too quickly in spots.

Not such a big deal on such small boxes as these, but it's just more of a personal preference thing. I'll hit them with the sander to key it a bit and it's still just porous enough for the contact cement to get a good bite, otherwise. If I don't end up veneering them, this is a great primer coat for paint for the same reasons either way.

I use titebond 3 for just about everything. As it has water clean up, I find it really easy to just smear it around with a wet paper towel. No odor of contact cement!

 

[MrBoat]

I use titebond 3 for just about everything. As it has water clean up, I find it really easy to just smear it around with a wet paper towel. No odor of contact cement!

I'm just accustomed to contact cement and I work mostly outdoors. The gel contact cement I can apply with a broad putty knife or a short nap, mohair roller and it sticks to just about everything and itself.

 

[ARES24]

I put about 4 coats (from the same mix) of alcohol thinned epoxy on the boxes so that I don't have to use 2 coats of contact cement if I veneer these.

I'm sorry, are you abusing alcohol!!! Instant downvote!

In all fairness, thanks for the simple notes on your progress, it helps everyone that hasn't done it a dozen times before.

 

[MrBoat]

I did manage to get some more done today.

Did the lay out for the drivers and the battens that hold the fronts and backs on.

Some builds I had seen where it appeared as if they notched out the clearances for the woofers after the battens were installed. That seemed like it would be a pain so I just Set them up on the baffles where they will be and transferred my woofer layout onto the battens. I have a band saw and a floor standing belt sander. I will see to make sure the woofers have enough breathing room etc.

The woofers are recessed from behind. I ended up using the circle jig for the first pass at it's longest point to the flats, and then just freehanded what oddities were left. There's a 32nd of clearance all the way around. This way, it will be easier to center the woofer. This is the inside of the baffle.

This is the side of the baffle you see. I am just using MDF for the baffles until I hear how they sound before doing anything decorative to them. In the event they are just mediocre, I will just paint or veneer them accordingly. Still need to cut the notches for the spade terminals for the tweeters.

These baffles get screwed in with gaskets. This is an idea of how they will look. This is actually the back of the cabinets with the full battens installed. I just set them in there for a look. It's nice when all your parts fit well universally.

I could have had these fired up today for a test drive. Took a break for grandkids and grocery/laundry chores.

 

[MrBoat]

Works out that there is plenty of clearance for the woofer, and just enough of a land for the gasket.