Bill's Overnight Sensations build diary

[williamrschneider]

I've made the plunge and purchased parts for what should be a fun build project - the Overnight Sensations designed by Paul Carmody.

I am one of the slowest builders on the face of the planet, so this thread may be active for a while, then disappear as things get busy elsewhere for me. For example, I'm still building Zaph ZDT3.5s from parts purchased last summer - over a year ago. (The good news is that they are almost finished!).

Once the drivers were in hand for this project, I measured them and began planning how to approach the cabinet (removable baffle, or removable back, etc.) I decided to tackle a removable back this time and try for a paint finish on these.

The first job was to lay out the cuts for the baffle, and router them outdoors. I pride myself for careful planning, and as you can see from the proudly made photo, I'm already making a mistake. The sharp-eyed will easily spot it. Thankfully I did too before making the cuts.



It made me grumpy with myself for even getting THIS far without seeing it. Oh, well, I'm sure that I'm not alone.

Here's a shot after routing the driver openings. I have more to say about that later.

[williamrschneider]

Re: Bill's Overnight Sensations build diary

While still pondering the details of the cabinet, I started to plan the crossovers. I do this after measuring each component, making a simple scale illustration in CorelDraw, and rearranging until I'm happy that things will work.

I decided to separate the tweeter and the woofer boards because of the small cabinet size of the Overnight Sensations. BTW, I had to substitute one inductor (1.1mH) for the specified brand because of an out-of-stock part. I also substituted a Dayton cap for the electrolytic. I tend to keep things for a while, and have had issues with old electrolytics after 15 years or so.

Tweeter board plan...



and woofer board plan...



Drilling the corner mounting holes in the boards...

[williamrschneider]

Re: Bill's Overnight Sensations build diary

I often use solder-type terminal strips to connect the various components. It keeps things tidy, and provides some mechanical robustness in the assembly.

However, I have available locally only Radio Shack terminal strips, and they have smallish openings for wires, especially if you have a fat inductor lead, a 16 ga. stranded wire to the drivers and maybe something else all going into one opening. I fought that on my ZMV5 build.

I've recently been enlarging the openings on my terminal strips using a Whitney Jr. punch that I had purchased back when I was an active engineer. It works slick for these, although it's a little slow.



The inset picture shows a combination of both before (triangular holes) and after some were punched.

[depthsounder]

Re: Bill's Overnight Sensations build diary

I pride myself for careful planning, and as you can see from the proudly made photo, I'm already making a mistake. The sharp-eyed will easily spot it. Thankfully I did too before making the cuts.

You were going to mirror image those baffles right?

:D

Looking good so far, I wish I could be building speakers, but the only wood I'm cutting these days is new counter tops in the kitchen.

BTW I have that exact same punch, it's great.

-David

[gorbs]

Re: Bill's Overnight Sensations build diary

nice work man.!! i confess i looked with dull eyes lol. didn't even think to look for that. i will be when i start my RB2 build though.

[philiparcario]

Re: Bill's Overnight Sensations build diary

You were going to mirror image those baffles right?

:D

Looking good so far, I wish I could be building speakers, but the only wood I'm cutting these days is new counter tops in the kitchen.

BTW I have that exact same punch, it's great.

-David

he did not make a mistake he was kidding he is going to stack those baffles and have a rigid faceplate. Can i spin doc or what!

[williamrschneider]

Re: Bill's Overnight Sensations build diary

You guys are sharp - especially Phil! (Phil - you should be in politics!)

David - just consider the countertop job as practice for speaker building!

Here's a shot of the tweeter crossovers awaiting population.



I used small sections of dowel as feet. I will put glue on the bottom of them, and drop them into position in the cabinet to dry. If I need to, I can still remove a crossover board afterwards by removing the screws holding it to the feet. However, I'm NEVER going to use dowels again!

In the past, I've used wooden strips to do the same thing, and it's much easier. Drilling pilot holes in all those dinky things was a pain, as was trying to drive the screws in without the darn things rotating. 'Twas an education in what not to do next time.

[williamrschneider]

Re: Bill's Overnight Sensations build diary

Here's what I alluded to in one of the earlier posts. I may remake the baffles because of the sloppy way the tweeter fits. I use a Jasper circle guide, and I've always been able to find a diameter that creates a nice fit with the driver. This time, the hole is a little sloppy around the edges. I may have to add a Router Buddy to my tools for cases like this. I LOVE the ease with which the hole diameter is set on the Jasper, but with metric drivers and non-metric Jasper settings it's sometimes inevitable that you can't get the hole you want.



The tweeter flange is 45mm outer diameter, and I found a 45 mm Forstner bit on Amazon that I have coming for this job.

I'll need the close fit that the forstner will provide for one other aspect of this tweeter too. When I countersunk the hole, I included a little bit extra depth for compressed gasket material.

But, duh..., there's no way to compress the gasket if the driver flange has no screw holes! I then decided I was going to make a jig to drill and countersink four holes in the tweeter flanges to hold #4 screws.

Catch 22...I can't make a jig with the proper diameter with my Jasper. That's why I ordered the 45mm Forstner. It will solve two problems - make a tight fitting jig for accurate positioning of screw holes in the flange, and make a tight counterbore on new baffles.

After writing this, I realize that I'm making a mountain out of a molehill. If I make another baffle with the depth of tweeter recess just right (no gasket allowance) and merely glue it in, I'd be fine. In fact, I'd be fine with what I have if I shim the tweeter back out flush using some cardboard.

We'll see if I come to my senses, or if I continue to tilt at windmills.

[WWWJD]

Re: Bill's Overnight Sensations build diary

Bill? You're running off and leaving me man!

[williamrschneider]

Re: Bill's Overnight Sensations build diary

Didn't want to clutter your build thread with my piddling around! Your version will have nifty features that mine won't, so I went off with my tail dragging.

[WayneN]

Re: Bill's Overnight Sensations build diary

I've made the plunge and purchased parts for what should be a fun build project - the Overnight Sensations designed by Paul Carmody.

I am one of the slowest builders on the face of the planet, so this thread may be active for a while, then disappear as things get busy elsewhere for me. For example, I'm still building Zaph ZDT3.5s from parts purchased last summer - over a year ago. (The good news is that they are almost finished!).

Once the drivers were in hand for this project, I measured them and began planning how to approach the cabinet (removable baffle, or removable back, etc.) I decided to tackle a removable back this time and try for a paint finish on these.

The first job was to lay out the cuts for the baffle, and router them outdoors. I pride myself for careful planning, and as you can see from the proudly made photo, I'm already making a mistake. The sharp-eyed will easily spot it. Thankfully I did too before making the cuts.



It made me grumpy with myself for even getting THIS far without seeing it. Oh, well, I'm sure that I'm not alone.

Here's a shot after routing the driver openings. I have more to say about that later.

[romanbednarek]

Re: Bill's Overnight Sensations build diary

The theory behind chamfering the inside of the baffle for a driver is to prevent the baffle from blocking the rear wave of the driver. Since a tweeter doesn't radiate into the enclosure, this isn't necessary. A chamfer is usually required for smaller drivers (or drivers with larger magnet structures) where the thickness of the baffle can block the openings of the woofer basket. My Microbe design which uses the RS125 was a particular design that required a chamfer and the picture below of that driver gives a good indication as to why a chamfer was a requirement for decent performance...

[nick29498141]

Re: Bill's Overnight Sensations build diary

Fantastic design/drafting there!

Nice shop, too!

NK

[Ryan_M]

Re: Bill's Overnight Sensations build diary

With regards to the front baffle and from all my research I was under the assumption that you only chamfer the woofer and not the tweeter? Have I misunderstood something along the way or maybe it doesn’t it matter?

Could just be clearance for around the wire terminals. Probably faster to chamfer the whole thing then try to notch out some space and it looks more 'finished' too. Just guessing....

BTW Bill the slop really doesn't look that bad in the pics. You could just try purposely off centering the jig base plate to eat up some of that inaccuracy, I've done that before. But I'm with you, I want a fully adjustable jig too.

[Paul Carmody]

Re: Bill's Overnight Sensations build diary

and as you can see from the proudly made photo, I'm already making a mistake. The sharp-eyed will easily spot it. Thankfully I did too before making the cuts.

Ha! I didn't catch that in your photo, which isn't much of a surprise, because I've done that gaff a few times, including when I first cut the boxes for this project. I think the bad baffle is still sitting in the scrap pile in my garage. Kudos to you for catching it before putting the bits to the wood.

By the way, your planning and use of jigs is exemplary. Thanks for the photos.