I noticed something that looks like a delta dj-30 jointer. Awesome. I passed up an opportunity years ago to bid on one at an auction due to it's weight, and my lack of foresight.
@6thplanet The Supermax drum sander is a 30+ year old USA made 5hp 25" single drum machine that I bought used about 20 years ago. When I bought a 14" planer, I bought it knowing I would get a wider drum sander for bigger things, this guy has fit that bill. Has done lots of work over the years for me.
@Eggguy said:
I noticed something that looks like a delta dj-30 jointer. Awesome. I passed up an opportunity years ago to bid on one at an auction due to it's weight, and my lack of foresight.
There is a story with everyone of the machines I have, none of them involve me going to a store and just buying them, I don't have that kind of money. This was when Delta Canada was still operating in Guelph Ontario (2001-2002'ish) and as part of my job I would end up passing through their warehouse and I kept seeing this huge jointer crate on the top shelf that was dinged up that looked like a return. After seeing it there month after month, I asked them what they wanted for it and ended up getting really great deal on a slight used 3hp 220v 1ph DJ-30 jointer. Later when I started selling Byrd tools, I upgraded it to a Shelix head. Very happy with this unit.
Work on the as of yet unnamed InDIYana 2024 isobaric project continues,
To go back a bit, the baffle was to be Bamboo, but the Bamboo shelf I bought to use as a baffle was riddled with random voids, so I switched to a Translam baffle. The sides were going to be Bamboo veneer, but I thought it looked too busy with the Translam front, so I decided to use some walnut I had kicking around to cover the Baltic Birch plywood. Plans change.
Last time I was at my favorite local sawmill, I picked up a bunch of random 6/4 live edge walnut boards to add to the stash for future use. Just as an aside, I have a great disfondness for epoxy encased live edge anything so saving boards from such a fate seems like a good deed right off the bat.
Pics of the board as retrieved from the basement, it didn't take much to make the split from the top and bottom connect and separate the board into two boards.
Boards were cut to length and resawn once for the first book match.
Once glued up, they were resawn again to make book matched book matched panels (bookmatched^2?).
Ran them all through the drum sander.
Monkeyed around with the layout, decided to make it so the left sides on both are the same and the rights on both are the same, as opposed to the left/right of each speaker being the same (if that makes sense).
I like to use a j-roller to spread out large amounts of glue, goes quicker and more evenly.
Used a torsion box for a ghetto cold press.
As per normal, trimmed things with a solid spiral flush trim bit. I prefer to do this in a table as opposed to free hand, I can easily limit the depth of cut per pass with the fence (usually just 1/8" max trim per pass) and things don't get away from my like they can free hand with a hand held router.
Used a Freud 1.5" roundover bit on the vertical front edges of the box. Took about 4 passes to full depth to be safe.
I was concerned how the 3/32" veneer would look at the top and bottom framing the translam, but I like how the look turned out.
Couple pics of the boxes all sanded and also showing the removable backs without port or terminal cups.
@Eggguy said:
I like the grain orientation on the sides, looks like you matched it nicely where it meets the top.
+1
I usually have the grain running vertical but the way you did it looks great! I wasn't sure I liked how the walnut overlapped the baffle in the first picture, but after you rounded over the sides I totally changed my mind. It looks really cool like that. Can't wait to see them with some finish and hear them in Indy in a few weeks.
@Eggguy said:
I like the grain orientation on the sides, looks like you matched it nicely where it meets the top.
+1
I usually have the grain running vertical but the way you did it looks great! I wasn't sure I liked how the walnut overlapped the baffle in the first picture, but after you rounded over the sides I totally changed my mind. It looks really cool like that. Can't wait to see them with some finish and hear them in Indy in a few weeks.
Grain wrapping around as normal needs to wrap or it looks bad (which is hard to do right).
This way, as long it was dark to dark at the top corner, it was going to look fine.
Hey, Dave-
I would advise more fill in the coax chamber as it will be sealed. You don't want resonances there to the point where the magnitude will have to be suppressed in the xover if you can avoid it. A loose roll of the wool you are using, or even so little as polyfil loosely filling the space will help suppress the sealed box resonance as well as the front to back standing wave. Wool on the inside back wall would also be a very good idea.
Got to thinking, is this your 1st 3way? Looking great!
Getting the midrange chamber Q and stuffing right is critical IME too - Good feedback, Wolf.
I do it with repetitive experimentation/DSP - but DSP alone cannot always make the midrange peak at the right place for that punchy - smack.
@Wolf said:
Hey, Dave-
I would advise more fill in the coax chamber as it will be sealed. You don't want resonances there to the point where the magnitude will have to be suppressed in the xover if you can avoid it. A loose roll of the wool you are using, or even so little as polyfil loosely filling the space will help suppress the sealed box resonance as well as the front to back standing wave. Wool on the inside back wall would also be a very good idea.
Got to thinking, is this your 1st 3way? Looking great!
Good point on the fill, I didn't use the same wool, but I did take a generous roll of the less dense "poly" and place it behind the Coax. When I ran an impedance sweep, I didn't see any major blips indicating a bad resonance, so I think its damped enough. That's where it would show up isn't it? (<- That's a question). I will be sure and take a pic of the fill when I switch over to the real upper back. Actually, I will go to my other computer and post the impedance sweep when I get home from work later.
It's not so much the "nasty resonances", but how much the self resonance has an affect on the measured bandwidth.
You can see it is already suppressed by 25 ohms or so in box, but that magnitude at 50 ohms will need some form of suppression to not cause a bump in the response of the woofer.
@Wolf said:
You can see it is already suppressed by 25 ohms or so in box, but that magnitude at 50 ohms will need some form of suppression to not cause a bump in the response of the woofer.
@DaveFred I hope you don't mind me asking in your thread...
So what forms of suppression are options? More stuffing? Notch filter? Aperiodic multi-chamber sealed (which I've only seen you do)? Anything else? How much more reduction in impedance should he target, and how do you determine that?
@Wolf said:
You can see it is already suppressed by 25 ohms or so in box, but that magnitude at 50 ohms will need some form of suppression to not cause a bump in the response of the woofer.
@DaveFred I hope you don't mind me asking in your thread...
So what forms of suppression are options? More stuffing? Notch filter? Aperiodic multi-chamber sealed (which I've only seen you do)? Anything else? How much more reduction in impedance should he target, and how do you determine that?
Please, by all means, Curious the answers myself as well.
Having a magnitude this high is the main reason I've done the aperiodic or multichamber versions. It makes the xover simpler and does it mechanically instead of electrically.
In the Monoculus, it was a high Q resonance, and I damped it electrically. It was at 198Hz, and i was using a 400Hz xover point. If I could have gone aperiodic in them, I likely would have, as this is really strong.
The Bottleships had an MAPD type dual chamber for the mid. It was to keep it more benign with the higher xover point for the 2" widebander. I was minimizing potential issues with the design being so small.
This is no different than the Fs resonance being underdamped in tweeters that makes them buzzy or nasal.
More stuffing can help, but then you risk making the mids sound stifled if too packed in. Loosely filled is good, then other measures.
Taking HD sweeps can tell part of the story, and listening with sweeps can tell you how obnoxious it sounds left alone. If it sounds fine or benign, then it is a matter of whether it hinders the xover enough that it affects the spectral tilt or shape of the FR, or the ability of the xover to meet its target or expected rolloff. Having a xover a few octaves above the resonance can help make the issue less troublesome, and minimize the required circuits. Sometimes a resistor is all that is required across the midrange, just as in the tweeter issue. Other times it takes an LCR or LC to electrically damp it.
In Dave's efforts above, it is 50 ohms at 72Hz or so, and the peak is rather high Q in shape instead of broad and shallow. With BSC coming, I can imagine the mid will need padded to match the woofer magnitude, and a resistor of 25-50 ohms across it will not attenuate more than a dB or 2 in output, but minimize the peak to half or less as a starting point and see how the xover works out. If the xover is at 400Hz tentatively, then that is about 2 octaves above the resonance. The mid chamber is large enough to keep the resonance low enough that the resistor trick may be all that is required, adjusting the value lower if needed.
Any suggestions or hints about the XO would be appreciated.
I have yet to listen to the XO, so I have no idea if this will be okay or sound like crap yet, parts are supposed to arrive tomorrow and then I can start to play around in the real world. About 1 week left, no rush, no pressure...
Yes, I am using high DCR air coils, I have other options in the tool box if this turns out to be a bad idea.
I was trying to keep the parts count down for the mid and tweeter as space is limited for where I wanted to put the board with those components. I did have more complex versions of the XO, but this was the least amount of parts I could use and still be happy. Might not have needed fourth order electrical on the woofer, but I have lots of space in the bottom compartment and wasn't as thrifty with the Iso woofer low pass circuit.
Comments
I noticed something that looks like a delta dj-30 jointer. Awesome. I passed up an opportunity years ago to bid on one at an auction due to it's weight, and my lack of foresight.
Yes, What he said !!!
@6thplanet The Supermax drum sander is a 30+ year old USA made 5hp 25" single drum machine that I bought used about 20 years ago. When I bought a 14" planer, I bought it knowing I would get a wider drum sander for bigger things, this guy has fit that bill. Has done lots of work over the years for me.
There is a story with everyone of the machines I have, none of them involve me going to a store and just buying them, I don't have that kind of money. This was when Delta Canada was still operating in Guelph Ontario (2001-2002'ish) and as part of my job I would end up passing through their warehouse and I kept seeing this huge jointer crate on the top shelf that was dinged up that looked like a return. After seeing it there month after month, I asked them what they wanted for it and ended up getting really great deal on a slight used 3hp 220v 1ph DJ-30 jointer. Later when I started selling Byrd tools, I upgraded it to a Shelix head. Very happy with this unit.
Thanks everyone for the kind comments so far, no points for pretty though, proof will be in the XO and how it sounds...
Helical cutters are the shit!
Looking forward to seeing (and hearing) these.
Work on the as of yet unnamed InDIYana 2024 isobaric project continues,
To go back a bit, the baffle was to be Bamboo, but the Bamboo shelf I bought to use as a baffle was riddled with random voids, so I switched to a Translam baffle. The sides were going to be Bamboo veneer, but I thought it looked too busy with the Translam front, so I decided to use some walnut I had kicking around to cover the Baltic Birch plywood. Plans change.
Last time I was at my favorite local sawmill, I picked up a bunch of random 6/4 live edge walnut boards to add to the stash for future use. Just as an aside, I have a great disfondness for epoxy encased live edge anything so saving boards from such a fate seems like a good deed right off the bat.
Pics of the board as retrieved from the basement, it didn't take much to make the split from the top and bottom connect and separate the board into two boards.
Boards were cut to length and resawn once for the first book match.
Once glued up, they were resawn again to make book matched book matched panels (bookmatched^2?).
Ran them all through the drum sander.
Monkeyed around with the layout, decided to make it so the left sides on both are the same and the rights on both are the same, as opposed to the left/right of each speaker being the same (if that makes sense).
I like to use a j-roller to spread out large amounts of glue, goes quicker and more evenly.
Used a torsion box for a ghetto cold press.
As per normal, trimmed things with a solid spiral flush trim bit. I prefer to do this in a table as opposed to free hand, I can easily limit the depth of cut per pass with the fence (usually just 1/8" max trim per pass) and things don't get away from my like they can free hand with a hand held router.
Used a Freud 1.5" roundover bit on the vertical front edges of the box. Took about 4 passes to full depth to be safe.
I was concerned how the 3/32" veneer would look at the top and bottom framing the translam, but I like how the look turned out.
Couple pics of the boxes all sanded and also showing the removable backs without port or terminal cups.
Next up, Applying finish....
Incredible
Kick ass.
Absolutely fabulous work and cutting that stuff on the bandsaw is just icing on this cabinet cake, Sir.
bow
I like the grain orientation on the sides, looks like you matched it nicely where it meets the top.
+1
I usually have the grain running vertical but the way you did it looks great! I wasn't sure I liked how the walnut overlapped the baffle in the first picture, but after you rounded over the sides I totally changed my mind. It looks really cool like that. Can't wait to see them with some finish and hear them in Indy in a few weeks.
Grain wrapping around as normal needs to wrap or it looks bad (which is hard to do right).
This way, as long it was dark to dark at the top corner, it was going to look fine.
Plus, I like the sapwood pattern
That's going to to look great with some finish applied.
I love the sap wood streaks.
Not a whole lot to say in this update,
This is all the easy stuff done, now to measure all three drivers and come up with a Crossover!
D@mn, that Osmo oil sure made the grain pop! I love watching your craftsmanship come together!
OOooOOh!
Hey, Dave-
I would advise more fill in the coax chamber as it will be sealed. You don't want resonances there to the point where the magnitude will have to be suppressed in the xover if you can avoid it. A loose roll of the wool you are using, or even so little as polyfil loosely filling the space will help suppress the sealed box resonance as well as the front to back standing wave. Wool on the inside back wall would also be a very good idea.
Got to thinking, is this your 1st 3way? Looking great!
InDIYana Event Website
Getting the midrange chamber Q and stuffing right is critical IME too - Good feedback, Wolf.
I do it with repetitive experimentation/DSP - but DSP alone cannot always make the midrange peak at the right place for that punchy - smack.
Good point on the fill, I didn't use the same wool, but I did take a generous roll of the less dense "poly" and place it behind the Coax. When I ran an impedance sweep, I didn't see any major blips indicating a bad resonance, so I think its damped enough. That's where it would show up isn't it? (<- That's a question). I will be sure and take a pic of the fill when I switch over to the real upper back. Actually, I will go to my other computer and post the impedance sweep when I get home from work later.
Yes, my first three way...
You might also see some extra energy in a waterfall plot.
Hello,
Here is the coax woofer section free air,
and here it is measured in box with the 2" wool around and a generous roll of poly batting behind it,
Since I don't see any major anomalies in the in box impedance sweep, is it safe to say there are no nasty resonances in the sealed upper portion?
Thank you,
David.
It's not so much the "nasty resonances", but how much the self resonance has an affect on the measured bandwidth.
You can see it is already suppressed by 25 ohms or so in box, but that magnitude at 50 ohms will need some form of suppression to not cause a bump in the response of the woofer.
InDIYana Event Website
@DaveFred I hope you don't mind me asking in your thread...
So what forms of suppression are options? More stuffing? Notch filter? Aperiodic multi-chamber sealed (which I've only seen you do)? Anything else? How much more reduction in impedance should he target, and how do you determine that?
Please, by all means, Curious the answers myself as well.
Having a magnitude this high is the main reason I've done the aperiodic or multichamber versions. It makes the xover simpler and does it mechanically instead of electrically.
In the Monoculus, it was a high Q resonance, and I damped it electrically. It was at 198Hz, and i was using a 400Hz xover point. If I could have gone aperiodic in them, I likely would have, as this is really strong.
The Bottleships had an MAPD type dual chamber for the mid. It was to keep it more benign with the higher xover point for the 2" widebander. I was minimizing potential issues with the design being so small.
This is no different than the Fs resonance being underdamped in tweeters that makes them buzzy or nasal.
More stuffing can help, but then you risk making the mids sound stifled if too packed in. Loosely filled is good, then other measures.
Taking HD sweeps can tell part of the story, and listening with sweeps can tell you how obnoxious it sounds left alone. If it sounds fine or benign, then it is a matter of whether it hinders the xover enough that it affects the spectral tilt or shape of the FR, or the ability of the xover to meet its target or expected rolloff. Having a xover a few octaves above the resonance can help make the issue less troublesome, and minimize the required circuits. Sometimes a resistor is all that is required across the midrange, just as in the tweeter issue. Other times it takes an LCR or LC to electrically damp it.
In Dave's efforts above, it is 50 ohms at 72Hz or so, and the peak is rather high Q in shape instead of broad and shallow. With BSC coming, I can imagine the mid will need padded to match the woofer magnitude, and a resistor of 25-50 ohms across it will not attenuate more than a dB or 2 in output, but minimize the peak to half or less as a starting point and see how the xover works out. If the xover is at 400Hz tentatively, then that is about 2 octaves above the resonance. The mid chamber is large enough to keep the resonance low enough that the resistor trick may be all that is required, adjusting the value lower if needed.
InDIYana Event Website
WOW! Very nice work.
Measurement time,
Any suggestions or hints about the XO would be appreciated.
I have yet to listen to the XO, so I have no idea if this will be okay or sound like crap yet, parts are supposed to arrive tomorrow and then I can start to play around in the real world. About 1 week left, no rush, no pressure...
Yes, I am using high DCR air coils, I have other options in the tool box if this turns out to be a bad idea.
I was trying to keep the parts count down for the mid and tweeter as space is limited for where I wanted to put the board with those components. I did have more complex versions of the XO, but this was the least amount of parts I could use and still be happy. Might not have needed fourth order electrical on the woofer, but I have lots of space in the bottom compartment and wasn't as thrifty with the Iso woofer low pass circuit.
Comments good or bad welcomed!