Build of Rick Craig’s Integrity Speaker

[Rick Sykora]

As promised, here is my build of the Rick Craig’s new DIY speaker called Integrity. It was designed as a tribute to Jeff Bagby so emulates his design values. The kit parts are a pretty reasonable $600 for a 3-way passive radiator design. The midrange, tweeter and PR are SB Acoustics and the woofer is a Dayton ES180TiA. I was already working with the ES180 and wanted to do a 3-way design, so was naturally interested in the Integrity. Am planning to downsize in the next few years and a compact bookshelf with good low bass also appealed to me.

The Integrity cabinet is 18” x 8.5” x 11”. It is a fairly simple cabinet, but has a couple of challenges. One is recessing the truncated midrange and the other is the PR cutout. I will address the PR cutout during the build. As for the midrange, Rick indicates that flush mounting is acceptable. However, this unit is getting Klippel test scrutiny, so he supplied a pre-cut front baffle to me. I was able to complete the rest of the cabinet with a piece of 2’ x 4’ x .75” MDF. This is about as big a board as like to handle on my table saw. The Integrity panels are sized to be foolproof. All opposing panels are the same dimensions. The center brace is also the same size as the top and bottom panels. See attachments for details (added after initial thread post).

To start, I took the MDF and crosscut it to 25.5” wide. This piece can then be ripped 9.5“ wide on each side to create 2 panels. Each of these panels can be crosscut at 18” to create the side panels. The remaining parts are used to create the top and bottom. They are already 9.5“ deep, so they just need to be trimmed slightly to 7” widths. The remaining panels, can be cut from the other half of the original MDF board. In my case, I need the back panel early, so I cut a 8.5“ x 18” section from the remaining board. You should have enough wood remaining to cut the midrange enclosure pieces. This is another panel just like the top, so can use it as a pattern. The midrange enclosure back is 7” x 7.125“.

At this point, you should do a dry fit of the cabinet to ensure the panels are correct and fit well. It is best to do this on a softer flat surface to avoid damaging parts if they fall over. Use the attached side view as a guide. NOTE: you will get the best results if the top, bottom and brace are square and sized to fit. If the outside joints are not smooth, trimming these pieces equally will save work later and produce a better cabinet.

You are now ready to start gluing. Take one of the sides and lay it on a flat surface. I use the top of my table saw. TIP: before applying glue, be sure to lightly sand the mating surfaces. Applying wood glue to the inside length (18" part) of the back panel attach to the edge of the side panel. Clamp lightly until glue sets. It should look this...

 

[q3cpma]

Is this missing pictures? Because I don't really understand what I'm supposed to see here.

Unrelated: the number of people using Dark Side of the Moon as avatar is starting to get confusing.

 

[ta240]

Is this missing pictures? Because I don't really understand what I'm supposed to see here.

Unrelated: the number of people using Dark Side of the Moon as avatar is starting to get confusing.

I think it is just step one of the assembly so only one picture so far.

 

[q3cpma]

I think it is just step one of the assembly so only one picture so far.

That's what I thought, but the "wall" of text about building with this single picture made me quite perplex.

 

[ta240]

True, I haven't followed a lot of build threads so it didn't surprise me that the only picture was when the project was stationary but it did skip pictures of the cutting; which might be dangerous one handed that many might include

 

[Rick Sykora]

Oops, forgot to attach the drawings. Just tried, but forum software is preventing some of them.

More build pics to come, but did not take any of the panel cuts. Sorry for wordy post, but hoped it would help beginners. Will draw panel cuts to help visualize. It is really simple...

 

[Rick Sykora]

More drawings...

NOTE: Rick Craig will supply more detailed these drawings with the kit. They are for the more experienced builder. For the less skilled woodworker, the plan is provide precut front and back baffles for purchase. I will supply more detailed drawings for some of the panels later in this thread.

 

[Rick Sykora]

Next is to glue the bottom to the back and side by applying glue to the inner walls. I usually apply glue to the part facing up and then to the adjacent edge of the mating part so the glue has less chance to run. Clamp and let glue set.

While the glue sets, if you have not built the woofer and tweeter crossover, suggest you do so as it helps with the next step. Crossover details are provided with the kit and so will not show here. If you are gluing the crossover to the bottom, you can skip this step (I prefer screwing it to the bottom in case I find I need to remove it later). I also line the bottom of the crossover board with butyl rubber gasketing to reduce vibration. Parts Express sells for about $5 per roll. I also use it to mount crossover components to keep them from vibrating too!

Once the bottom glue has set, place the crossover towards the back corner of the cabinet. Leave some room behind it for foam dampening to be added. Here is my pic...

After you drilled screw holes in each of the four corners, suggest you remove it to keep it clean (even though I kept mine in for this build).

 

[Rick Sykora]

Before you can proceed further, you will need to cut the brace. I did this with a 2 3/8 hole saw and a handheld saber saw. Refer to the attached file for details. While the inner cutout is supposed to be rectangular, I find it easier to cut out with a hole saw, so Rick approved the oval shape.

Next step is to glue in the top, brace and midrange enclosure. For simplicity, you may want to glue the top first and, after it sets, add the brace and midrange enclosure...

 

[maverickronin]

Is this Winkleswizard?

Did you change your handle?

That's even more confusing...

 

[Rick Sykora]

Is this Winkleswizard?

Did you change your handle?

That's even more confusing...

Yes, same person, just decided I wanted to make it simpler to know who I am.

I also have a business and it has 2 names (legal entity and marketed one). This has caused some confusion (notably with getting paid!). So now am the same name whether you are dealing with bank or PayPal, etc.

 

[somebodyelse]

Thanks to all involved, whatever their handle. I guess the scattering of information is to be expected at this stage of a new build - that's the price we pay for seeing it as it happens. I'm looking forward to see how things progress.

 

[Rick Sykora]

Now, we can add the other side panel (sorry no pic here, but if not obvious by now, you are probably in trouble)...

Wait the full 24 hours or however long it takes for your glue to fully cure. Find a good solid working surface and add the passive radiator cutout. You can do by router, but probably best left for the more experienced. Other than buying the back baffle, if you want to recess the cutout, you will need a router or a CNC. Since it does not need to be recessed, I did using a 4.75 inch hole saw. You will need to make 2 holes and trim the excess. Please see attachment for specific dimensioning information. Note, to make simpler, my drawing is slightly different than the one posted earlier (done by fancy CNC owner). Yes, am a bit jealous . Before you cut, make sure you are doing so at the top portion of the cabinet behind the midrange enclosure!

When done, it should look like this...

Now is a good time to drill some pilot holes. Get out a passive radiator, center it and mark mounting holes. Remembering the top and sides of the upper chamber get foam lining, place the midrange crossover (with large inductor at top) and mark holes to mount it. Note you will also need a couple of 1/4“ holes along the bottom edge to run the tweeter and midrange wires into their sub-enclosure. Note the white wire and copper one are routed through to the midrange enclosure. I used white to differentiate the tweeter signal wire. Both wire holes will need to be sealed completed wth silicone caulk. I used some butyl rubber sealant to temporarily seal the holes.

Finally, plan your preferred binding posts and drill and/or cut holes for it. I use the knock-in type, so the drawing just shows a couple of 1/4” holes for them. Whatever you use, consider the large inductor for the woofer crossover will be on the other side. Also, remember you may need some room to connect the crossover wiring internally. I placed the binding posts about 4” from the bottom and it worked out well.

 

[Selah Audio]

Thanks for starting this thread. Meniscus Audio will be handling the kit sales and making a donation to Jeff Bagby's family for each kit that is sold. The kit should be going live on the Meniscus site this week. I'm in the process of putting together the assembly plans as well as the measurement graphs for the response, impedance, and other aspects of the design. I look forward to Amir's testing as well.

There will also be an assembled pair to be auctioned or raffled to create a college scholarship for Jeff and Christine's son David. He's been accepted to pursue a major in architecture.

 

[Thomas savage]

This is great , thanks for sharing it mate .

 

[Rick Sykora]

Before gluing the front baffle to complete the cabinet, you should cut the foam that will line the lower cabinet. Before you put the foam in, vacuum out the cabinet and wipe the inside for sawdust. All surfaces should be covered except the crossover board. While you may want to glue the foam in place, suggest you leave that until after you sand and finish the cabinet. One possible exception is the piece on the underside of the brace.

Here is how it should look...

There is no foam in the midrange subenclosure, but it will get some loose dampening material later.

 

[Rick Sykora]

As the foam liner will just get dirty with sawdust, remove and set aside for after sanding. At this point, it is best to mount the woofer/tweeter crossover board in the bottom of the cabinet. It may get a little dusty, but a little vacuuming and/or canned air should resolve. Now, remember to rough up the mating surfaces and have a wet rag ready. The front baffle should get a generous bead of glue to ensure a good airtight seal. Wipe the excess glue, and allow to dry completely. Next fill any cracks or voids with wood filler and sand thoroughly. Vacuum, wipe down again and put the foam lining in. You should be here...

 

[Rick Sykora]

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...

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...

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.

 

[Rick Sykora]

So, it is time for some listening and I will start with the caveat that I am not trained and am not used to listening in mono. That said, my quick sample of music for listening consists of Adele, James Taylor, Peter Gabriel and a bit of Vivaldi by Apollo’s Fire. I have heard most of these artists live so hoping it gives me some edge...

Am not going to go into much detail on individual tracks as my goal here is just to test if anything seems amiss. The speaker was on a stand, pointing diagonally Into the room and well away from walls. My initial takeaway is I am impressed by how articulate the Integrity sounds. Some tracks I picked specifically for bass content and was pleased to find I could distinguish the notes readily. The Integrity also impressed me with a soundstage much beyond the box. I was listening in a darkened family room and often strained to locate its exact position.

Having pleasingly completed my listening session, am now carefully removing drivers and binding posts to preparing to do some painting. I have also removed the butyl rubber from the wiring holes in the midrange enclosure. Since I have validated the design, will be using some clear silicone caulk to more permanently seal the wires in their holes.

 

[Rick Sykora]

Here is a look after a protective coat of Duratex.

It will ship back to Rick before going to Amir for testing.

Parts are now available at Meniscus Audio for those who might be interested.

On to the next build!