Build of Rick Craig’s Integrity Speaker

[Selah Audio]

Thanks for helping make this happen. I'll test the speaker and ship it to Amir next week.

 

[bigjacko]

How is the Duratex coating? The top of front baffle got some hair like stuff, is it because of the brushing method? What finishing do most people do with their speaker?

 

[Rick Sykora]

How is the Duratex coating? The top of front baffle got some hair like stuff, is it because of the brushing method? What finishing do most people do with their speaker?

Lol, Duratex is a textured paint...

What you see (although somewhat distorted by camera angle) is the finish you get applying Duratex with a standard roller. It could be brushed to have a grainy appearance but not worth it for this speaker. The default finish is much like pro equipment. This speaker is just getting some paint to protect it on the road. Without it, MDF tends to drink liquids and can deform badly if exposed to water.

Many DIYers either paint or veneer their speakers. Am not sure how popular Duratex is as a paint for home speakers, but most of my previous work used black spray paint. As my speakers go in a dark home theater, black is perfect for hiding them. I like Duratex better than spraying, but you have to like it’s textured look. In my experience, getting a nice finish is more work than any other part of building most speaker cabinets.

I filled gaps, sanded them thoroughly and used thick paint, but the seams still show more than I like.

 

[Ron Texas]

Now we can wire up the drivers and do some acceptance testing. If you did not catch when wiring the crossover, both the midrange and tweeter are supposed to be wired in reverse polarity. Also, remember to ensure wire holes for the smaller drivers are sealed well. Put the passive radiator on last, but before you do, Rick specs a bit of poly-fill behind the woofer and behind the PR.

Now I do my usual measurements to verify the build (NOTE these are a bit preliminary at this stage). According to my multimeter, the DCR is a healthy 7 ohms. Next lets look at the impedance and phase...

View attachment 69438

Looks pretty good (and is very comparable to Rick's prototype). This is a solid 6-8 ohm design without any major phase issues, so should be an easy amplifier load. Resonances also appear to be well-controlled as the curves are quite smooth too.


Moving on to a frequency response measurement. This was done at REW 75 dB reference level, gated, on-axis at a distance of 30 inches with 1/12 smoothing...

View attachment 69413
For the purposes of this exercise, all appears functioning nominally. Since gating took out the response measurement below 300 Hz, I will add the the f3 for this design is in the mid 30s. No complaints about the bass from me. More in my listening tests. I did notice that I had to crank up my amp a bit more than usual to get the 75 reference level. Rick confirmed that he traded off some sensitivity for lower bass. He says it is about 82 dB. He will provide better and more detailed measurements later, so do not read too much into my crude ones just yet.

Awesome. I have neither the tools or skills to do this, but I am glad you did it.

 

[Inner Space]

Love it - great work, & congratulations. May I ask a super-nerdy question? What kind of glue did you use?

 

[bigjacko]

Lol, Duratex is a textured paint...

What you see (although somewhat distorted by camera angle) is the finish you get applying Duratex with a standard roller. It could be brushed to have a grainy appearance but not worth it for this speaker. The default finish is much like pro equipment. This speaker is just getting some paint to protect it on the road. Without it, MDF tends to drink liquids and can deform badly if exposed to water.

Many DIYers either paint or veneer their speakers. Am not sure how popular Duratex is as a paint for home speakers, but most of my previous work used black spray paint. As my speakers go in a dark home theater, black is perfect for hiding them. I like Duratex better than spraying, but you have to like it’s textured look. In my experience, getting a nice finish is more work than any other part of building most speaker cabinets.

I filled gaps, sanded them thoroughly and used thick paint, but the seams still show more than I like.

Thank you for detailed respond. I was wondering why the front baffle looked like that but the top and back were smoother. If you don't like the gaps, have you tried wood filler? I don't know much about it but guess it should have similar property to wood, so should be able to paint or veneer on it.

 

[Rick Sykora]

Love it - great work, & congratulations. May I ask a super-nerdy question? What kind of glue did you use?

I use Titebond Premium for the initial glue joint and, after it dries, some Original to seal if needed. If am in a hurry, Titebond will set in about 20-30 minutes. Before I unclamp, I may add the additional glue to seal the joint better. So, can build most cabinets in less than a day, but they need a full 24 hour curing before stressing.

 

[Rick Sykora]

Thank you for detailed respond. I was wondering why the front baffle looked like that but the top and back were smoother. If you don't like the gaps, have you tried wood filler? I don't know much about it but guess it should have similar property to wood, so should be able to paint or veneer on it.

As I mentioned, the difference you see is more camera angle than anything else. This pic is after the first (protective priming) coat. Would use at least 2 coats if I wanted a more professional finish. I did use wood filler, but conservatively and the one joint popped a little. If the speaker was to be showroom quality, it would be getting more sanding and more coats of paint. This would usually fill in the joint without need for wood filler.

This is a test speaker and the finish will get marred in travel and test fixtures. If/when I get it back, will give it a more final finish.

 

[Inner Space]

I use Titebond Premium for the initial glue joint and, after it dries, some Original to seal if needed. If am in a hurry, Titebond will set in about 20-30 minutes. Before I unclamp, I may add the additional glue to seal the joint better. So, can build most cabinets in less than a day, but they need a full 24 hour curing before stressing.

Rick, many thanks. I have to build a weird bracket thing to support a TV, in 3/4" MDF, and I was going to screw-and-glue, but now maybe I'll just glue it.

 

[Selah Audio]

Rick Sykora sent his speaker to me. I tested it against the prototype and shipped it out today. Amir should have it early next week. Meniscus Audio is selling the kit and making a donation to Jeff Bagby's family for each pair that is sold. I also can provide front and rear panels cut on a CNC for those that would rather not machine them.

The speaker going to Amir has the basic crossover except for metal oxide resistors in the midrange and tweeter sections. The crossover options at Meniscus include capacitors and resistors. The inductors are the same regardless of which crossover you choose to build.

 

[Duke]

View attachment 69120

Hi Rick,

Not that this is any of my beeswax, but in my experience a low percentage of cable ties fail in the field. Some of them just crack in two for no apparent reason, and on some of them the "teeth" in the head lose their grip.

My day job is building high-end bass guitar cabinets. The (unfortunately not hypothetical) nightmare scenario is, the bass cab of a customer in New Zealand has a mysterious buzz on certain notes which he cannot track down, so it has to go back to the factory (me) for troubleshooting.

Often you can pass two cable ties through the same hole, the second one being the insurance policy. You might have to drill out the opening on that big inductor. While it will be difficult to force the fourth cable tie through the opening in the pegboard, it can be done. Get the tip to poke through just enough so you can grab it with needle-nosed pliers.

Anyway like I said this is none of my beeswax, and admittedly bass cabs lead a harder life than home audio speakers, so it may not be applicable.

 

[ROOSKIE]

I filled gaps, sanded them thoroughly and used thick paint, but the seams still show more than I like.

Often you will seal the exposed edges of mdf with light layer of wood glue or bondo resin. Otherwise they suck up moisture in he paint and expand.

 

[bigjacko]

Often you will seal the exposed edges of mdf with light layer of wood glue or bondo resin. Otherwise they suck up moisture in he paint and expand.

Do those glue get back to liquid form if touch water or paint?

 

[amirm]

The review for this build is posted: https://www.audiosciencereview.com/...selah-integrity-diy-speaker-kit-review.15695/

 

[ROOSKIE]

Do those glue get back to liquid form if touch water or paint?

No not at all (wood glue would if you soaked it but not with painting). Use wood glue or fiberglass resin. They will be fine.

 

[BostonJack]

Thanks for presenting this. The Meniscus site shows photographs of a beautiful construction with radically beveled front baffle and a lovely rosewood veneer.

Any comment on the difficulty of doing that style of front baffle? Does it have any negative sonic effects?

Jack

 

[ROOSKIE]

Thanks for presenting this. The Meniscus site shows photographs of a beautiful construction with radically beveled front baffle and a lovely rosewood veneer.

Any comment on the difficulty of doing that style of front baffle? Does it have any negative sonic effects?

Jack

Hi, that baffle may help with diffraction. The difficulty is high, essentially you would want to be very experienced or have an experienced friend assisting the build.
If you are new a rectangle is much easier to build and much easier to veneer.

 

[jtwrace]

https://www.diyaudio.com/forums/in-memoriam/376162-rip-rick-craig-selah-audio.html#post6763088

 

[Kustomize]

RIP Rick Craig.