• Welcome to ASR. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Small 2-way speakers with linear on-axis and power response characteristics (Scan Speak and SB Acoustics drivers). H&V off-axis measurements included

Baltic birch is going to be a bit of a pain for me. What are good round-over bits that prevent tearout? A Frued Quadra bit? I have a 1/4-inch shank.
Freud Quadra cut are nice bits but shouldn't matter that much as long as the bit it relatively new. Take no more than a 1/4 inch off at a time. For your next-to-last pass, leave only 1/8 to 1/16 inch, therefore your final pass is taking off very little material and should not cause any tear out.
 
@carbidetooth I figure you're the go-to person for this. This morning, I tried putting a round over on my cabinets. Disaster struck. I got a nice tearout and gouged the front baffle. Cabits are a write-off. Will post pictures shortly. I have only worked with MDF, so I could easily patch with Bondo, sand, and veneer over.

Baltic birch is going to be a bit of a pain for me. What are good round-over bits that prevent tearout? A Frued Quadra bit? I have a 1/4-inch shank.
Without knowing just what the mode of failure was, I'm guessing at some of this. 1. Birch is a fairly hard hardwood and all the plys in Baltic Birch are hardwood, unlike domestic plywood. Couple to that every other ply has grain running 180° to the adjacent plys. BB ply is splintery and it's easy to get a sliver that tears along face grain, I've done it many times.
I looked to see what the Quadra cutters were as I'm not familiar. In theory 4 cutting edges would have better engagement in whatever is being cut and perhaps reduce chatter, but chip clearance ability will be affected, and more friction always equals more heat. I always look to the commercial world to assess value of "new, improved" mass market products. Fewer cutting edges and faster feed speeds are often the goodness when working on CNC, but handheld is different. Marketing is everything in the hobbyist market and I'm kind of a curmudgeon.
Sharpness in any cutter is a key. Climb cutting and smaller bites can be helpful. In the case of roundovers that means progressively dropping cutter rather than trying to take it all in one pass. Weirdly, steel can be sharpened to a finer edge than carbide but will pale in durability and they're increasingly hard to find.
Perhaps all is not lost on the cabinets. Maybe the corner could be removed and a "feature" glued in place. Photos and I can better assess. Both cutter and victim... I mean cabinets;)
 
@carbidetooth I figure you're the go-to person for this. This morning, I tried putting a round over on my cabinets. Disaster struck. I got a nice tearout and gouged the front baffle. Cabits are a write-off. Will post pictures shortly. I have only worked with MDF, so I could easily patch with Bondo, sand, and veneer over.

Baltic birch is going to be a bit of a pain for me. What are good round-over bits that prevent tearout? A Frued Quadra bit? I have a 1/4-inch shank.
I’m not an expert by any means, but I’ve found Whiteside and Amana bits to be of good quality. They are pricy though. I use them for my flush cut bits. Although I will say, the Bubinga veneer I’m using is putting them through thier paces.

IMG_6750.jpeg


Another tip is to make sure your bits are clean and any guide bearings are lubed. (Nothing that will stain the wood your cutting though)

I use the quality aerosol bearing lube they sell at woodcraft.

I mucked up one side of my veneer b/c the guide bearing seized and I didn’t realize it. :facepalm:
 
hvMXzojS.jpg
RRkXRi3U.jpg
-TZRlviI.jpg
MnRdsTtQ.jpg
PItV34W_.jpg


I do like the aesthetics of the roundover on all the edges. I would have just had to sand out the burn marks. Instead I pooched the whole job.
 
I do like the aesthetics of the roundover on all the edges. I would have just had to sand out the burn marks. Instead I pooched the whole job.
I'm guessing the bearing on your roundover cutter fell into driver rabbet? But for the one area dipped out there, it could be salvaged with corner inlays or cutting chamfers, but it would be considerable work. I'd be inclined to use glazing putty to fill the defects, sand and trim flat, then paint. Plywood takes more work to prep, but certainly can be painted successfully. I'm a little surprised to see the innards installed prior to finishing, but that's me.

I also like roundovers all around a cabinet, but don't like the appearance with plywood, favoring chamfers. The blend line from round to flat highlights any irregularity in veneer thickness. I just finished a pair of painted speakers with 3/8" roundovers everywhere, but did use MDF.
 
I'm guessing the bearing on your roundover cutter fell into driver rabbet? But for the one area dipped out there, it could be salvaged with corner inlays or cutting chamfers, but it would be considerable work. I'd be inclined to use glazing putty to fill the defects, sand and trim flat, then paint. Plywood takes more work to prep, but certainly can be painted successfully. I'm a little surprised to see the innards installed prior to finishing, but that's me.
Bingo. I should have placed the router on the baffle instead of the sides.
I'm a little surprised to see the innards installed prior to finishing, but that's me.
I had never planned on creating roundovers. I had already applied a coat of polyurethane and tapped up the port and drivers. With the power of ADHD, you can ruin anything at a moment's notice. I'm currently in the process of using Bondo to patch up the cabinet.

This cabinet is a slight variant of the original recipe, so I figured I would finish the job and take some measurements. Differences are a 50mm port turned to 53-55hz and an MDF window brace. Displacement has been calculated for both. The front baffle is the same dimension, but the depth has been increased. The net internal volume should be a true 8L. I have read all the posts quite a few times. I will need help taking a full spin of measurements, but that's down the road.
 
I'm guessing the bearing on your roundover cutter fell into driver rabbet? But for the one area dipped out there, it could be salvaged with corner inlays or cutting chamfers, but it would be considerable work. I'd be inclined to use glazing putty to fill the defects, sand and trim flat, then paint. Plywood takes more work to prep, but certainly can be painted successfully. I'm a little surprised to see the innards installed prior to finishing, but that's me.

I also like roundovers all around a cabinet, but don't like the appearance with plywood, favoring chamfers. The blend line from round to flat highlights any irregularity in veneer thickness. I just finished a pair of painted speakers with 3/8" roundovers everywhere, but did use MDF.
Do you have any photos of chamfered edges with Baltic Birch? I would love to see your painted work as well
 
Machano23 sealed? If I know I’m going to use these speakers with a subwoofer, any reason not to build it sealed? I have limited space in my office and building sealed reduces box size (with the usual higher bass f3). I know the response has been modeled by another member but are there any other sound quality issues to building it sealed, ie changes in group delay, phase etc? If the change is gonna degrade sound quality I’ll build it ported or with PR, but if not, I’d prefer building it sealed. Thoughts?
 
I know the response has been modeled by another member but are there any other sound quality issues to building it sealed, ie changes in group delay, phase etc?
Do you have a link to the simulation?

Yes, group delay improves due to the lower slope of the cabinet-induced high-pass filter. Of course you lose low bass, but then the subwoofer takes over. Coupling to a subwoofer is probably a little less complicated with a closed satellite speaker.

Depending on the level requirement, I nevertheless build satellite loudspeakers, i.e. those that I develop for combination with subwoofers, in bass reflex. The port then contributes a portion of the level at the crossover frequency, so that the bass-midrange driver is relieved of some of the load there.

Speaker development is a bunch of compromises. :)
 
What kind of paint do you recommend for painting? I have used gloss lacquer paint for piano finishes, but I want something easy and maybe a matte finish. Since I did not originally want to paint these, I'm looking to spray paint these.

I don't have the energy to use a spray gun.
If you're limited to aerosol cans, I think high build primer and topcoat from the automotive world would work best. It's going to take mulitple prime coats and subsequent sanding to get plywood ready to topcoat. Be careful though, not all spray can products have compatible formulas and solvents. If you decide to spray with a gun, Benjamin Moore STIX primer and Command Urethane topcoat is what the contrasting panel cabinets in last photo were done with. I suppose you could consider something like Duratex, although I'm not a fan.
 
If you're limited to aerosol cans, I think high build primer and topcoat from the automotive world would work best. It's going to take mulitple prime coats and subsequent sanding to get plywood ready to topcoat. Be careful though, not all spray can products have compatible formulas and solvents. If you decide to spray with a gun, Benjamin Moore STIX primer and Command Urethane topcoat is what the contrasting panel cabinets in last photo were done with. I suppose you could consider something like Duratex, although I'm not a fan.
1748999301769.png
GOT IT THANKS!
 
Do you have a link to the simulation?

Yes, group delay improves due to the lower slope of the cabinet-induced high-pass filter. Of course you lose low bass, but then the subwoofer takes over. Coupling to a subwoofer is probably a little less complicated with a closed satellite speaker.

Depending on the level requirement, I nevertheless build satellite loudspeakers, i.e. those that I develop for combination with subwoofers, in bass reflex. The port then contributes a portion of the level at the crossover frequency, so that the bass-midrange driver is relieved of some of the load there.

Speaker development is a bunch of compromises. :)
Thank you, good feedback. Leaning towards sealed, smaller cabinet volume so I can decrease depth of cabinet…the (relatively) deep cabinet is limiting factor in my intended placement.
 
Back
Top Bottom