AudioCircle
Industry Circles => GR Research => Topic started by: russellberg on 25 Nov 2020, 04:06 am
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I am starting an open baffle sub and I am using wood from a cherry tree that a friend cut down. I got someone to rough mill the tree into 3 ½" boards and it has been drying for 2-3 years. I am ready to use it now. It may not look like much yet but the cherry wood really shines once it is dressed properly. Here is the design that I have come up with. I am planning to have both drivers facing forward.
(https://www.audiocircle.com/image.php?id=217398)
The baffle will be 1½" of MDF and I will paint it black. Everything else is going to be cherry. I am not going to be using no-res. I may be wrong but I am feeling like the mass of the 2-2½" side, top and bottom panels will limit resonance. Also, the look of the exposed foam isn't really for me. The amp will be mounted in the bottom section of the build. I am pairing this with X-SLS Encores so I don't need it to act as a stand for bookshelves.
(https://www.audiocircle.com/image.php?id=217399)
Can you see the open baffle H frame in that chunk of wood? :) Its fun to take what is just this side of a tree and turn it into something like a speaker.
(https://www.audiocircle.com/image.php?id=217400)
(https://www.audiocircle.com/image.php?id=217401)
I had a lot of checking in some of the raw boards so I could sometimes break them apart, sometimes I had to saw them apart. Then I would mill a clean edge on each one and glue them back together to get the wide 14-15"panels. You always have to oversize your pieces in a project like this because there is always wood movement once you start sawing.
(https://www.audiocircle.com/image.php?id=217404)
I would cut to rough length with the circular saw then strike a string line down one edge. Then I ran it through the band saw to get one relatively straight edge. This picture doesn't show the correct sequence, I can't remember why, but next I would typically take it tow the table saw to cut the wane off of the other edge of the board.
(https://www.audiocircle.com/image.php?id=217405)
The boards are 3½" thick so I had to run it through the table saw once, then flip it over and run it through again to get a through cut.
(https://www.audiocircle.com/image.php?id=217406)
This gave me one edge that was pretty close to flat and I cleaned it up my jointer and a hand plane.
(https://www.audiocircle.com/image.php?id=217407)
This is why I spent so much on a bandsaw. To be able to cut through 13¼" of solid cherry is a very cool thing.
(https://www.audiocircle.com/image.php?id=217408)
I didn't take a picture with the thickest board but here I am resawing a much smaller piece. When I did the big piece the red blade guide is retracted all the way up into the saw.
(https://www.audiocircle.com/image.php?id=217409)
This is as far as I've gotten. Its all the pieces I need for one open baffle H frame with the sub mounted underneath. My garage is not heated so I have brought everything inside so that I can get any last wood movement happening. When you resaw wood you release a lot of tension within the wood and it is not uncommon for even quite dry wood to move after resawing. Everything is well oversized so that I can mill out any cupping, twisting, or bowing. Much of it will have to done with hand plane because my planer is not big enough for some of these pieces but I really enjoy the hand work. You will notice the checking that is still present in some of the long side pieces. I am going to fill them with black epoxy and then inset some purple heart bow-ties to hold the cracks in place. I just got the shipping notice from Danny for my drivers and the amp so I am excited for them to arrive!
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I got someone to rough mill the tree into 3 ½" boards and it has been drying for 2-3 years. I am ready to use it now.
Love that!
Making just one, or hopefully two?
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Love that!
Making just one, or hopefully two?
Just one for now is all the budget will allow. I have already built one of Danny's sealed subs so I am hoping to integrate the open baffle unit with my sealed sub to give me more even and responsive bass response.
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Looks like a great wood project and then I keep going back to what is that receiver up on the shelf?
I will be watching for updates and pictures. Man I remember wanting all those eq settings on my stereo to :thumb:
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Looks like a great wood project and then I keep going back to what is that receiver up on the shelf?
I will be watching for updates and pictures. Man I remember wanting all those eq settings on my stereo to :thumb:
Haha, can't believe you noticed! That is a 30 year old Radio Shack unit! Still makes sound but I don't use it that often as I am almost always listening to audio books when I am working with wood. With the little earbuds I can keep my ear protection on.
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Well, it is starting to look like a sub. I decided to do the baffle out of two ¾" layers of MDF and paint it black. Am I ever glad I did. I am usually an all wood guy but I think this contrast really looks good.
(https://www.audiocircle.com/image.php?id=217748)
Here is a dry fit before I had cut the dado for the middle dado.
(https://www.audiocircle.com/image.php?id=217749)
Hopefully we can learn from each other's mistakes. Here I screwed up by cutting the dado on the wrong side of the line so I ended up with a dado that was double the thickness it should have been. I will cut an extra piece and fill it in. I've got some pieces with similar grain so I don't think it will be too noticeable.
(https://www.audiocircle.com/image.php?id=217750)
I did the finish on the inside parts before I did the glue up. I sand to 220, then buff with two different compounds, and then buff in the wax. The finish is so smooth and lustrous and I love the way it feels and looks but it would be impossible to get my buffing wheel inside the boxes so I have to do it first.
(https://www.audiocircle.com/image.php?id=217751)
I had put the green masking tape on to prevent the finish getting on to the parts of the wood where I need the glue to go. Glue will not bond properly to wood that has been waxed.
(https://www.audiocircle.com/image.php?id=217752)
The glue up is a little tense with 7 pretty tight dadoes that all have to line up correctly but it went together pretty nicely. I tried to use the minimum amount of glue but I still had a little squeeze out. I waited until it was nearly hard, kind of rubbery feeling and then it scrapes out pretty nicely. It comes off the waxed surfaces very easily. I'm really happy with how it is looking so far. The amp will go in the cavity at the bottom.
(https://www.audiocircle.com/image.php?id=217753)
I also got the frame for mounting the amp cut out and installed. I made this with ¼" cherry plywood laminated on a piece of ¾" MDF. Every other piece of wood in this design has the grain running in the same direction. I am hoping that this, along with the fact that all the wood came from the same tree will help keep any wood movement consistent so that it isn't pulling against itself. With this piece and the corresponding piece that will cover the front of the amp cavity I could not line up the grain direction so I did it with plywood and MDF which will not move. This was also part of the reason for making the baffle out of MDF. I'm getting close to the finish line and I'm excited to hear it. Any questions let me know.
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Looking good! I'll bet the realization on mis-cut dado was a moment. I've done (perhaps more than) my fair share. The good news is we get to learn, eh? Thanks for taking us along for the ride. I really enjoy reading and looking at other people's projects.
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Looking good! I'll bet the realization on mis-cut dado was a moment. I've done (perhaps more than) my fair share. The good news is we get to learn, eh? Thanks for taking us along for the ride. I really enjoy reading and looking at other people's projects.
I know that I have learned more from figuring out how to fix my mistakes than I do on a project that goes smoothly.
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:D a simple trick is a little X on cutting side. Just saying. That sub is gonna be very nice. Very heavy. :D
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I've thought for a while that mounting the amp this way would be the nicest way to do it from the perspective of a finished-looking speaker. Either leaving the amp in a separate box or even those that had the amp laying flat in a box that was somehow attached to the back of the frame just seemed to be a compromise/workaround to mounting the plate amp for what it is - a plate amp (and this keeps the wiring runs to the drivers hidden, neat, and as short as can be too). I'm glad to see somebody put it together this way. That is going to be a really nice looking subwoofer! :thumb:
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I've thought for a while that mounting the amp this way would be the nicest way to do it from the perspective of a finished-looking speaker. Either leaving the amp in a separate box or even those that had the amp laying flat in a box that was somehow attached to the back of the frame just seemed to be a compromise/workaround to mounting the plate amp for what it is - a plate amp (and this keeps the wiring runs to the drivers hidden, neat, and as short as can be too). I'm glad to see somebody put it together this way. That is going to be a really nice looking subwoofer! :thumb:
The problem for many would be the added height which may not be ideal if you plan to build dual subs to set monitors on top of them. However, the monitors can perch on stands close to the subs, but you encounter another kind of clutter issue. Nevertheless, I prefer this approach and would angle monitors downward to compensate for the height. Just need longer speaker cables to reach up to the monitors.
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:D a simple trick is a little X on cutting side. Just saying. That sub is gonna be very nice. Very heavy. :D
Absolutely, I use that trick a lot, until I get careless and I don't ;)
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The problem for many would be the added height which may not be ideal if you plan to build dual subs to set monitors on top of them. However, the monitors can perch on stands close to the subs, but you encounter another kind of clutter issue. Nevertheless, I prefer this approach and would angle monitors downward to compensate for the height. Just need longer speaker cables to reach up to the monitors.
Yes, I am running it with X-SLS's so the height isn't an issue for me. I just couldn't see having the amp in a box on the floor, plus my wife would never go for it.
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I just couldn't see having the amp in a box on the floor, plus my wife would never go for it.
I got three plate amps on the floor. Yeah, they're in the way. I have to step over wires and power cords every time I power up my system. Dust magnets, too. One of my amps lies on the floor because the power cord wants to come undone when the amp is upright. It's a small price to pay for the incredible sound, though. You're gonna love your sub.
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Beautiful work! I love the look and the cherry wood.
I have had a few amplifiers with front panel in cherry, so nice.
Regarding no-rez or similar: While I don't think you will have problems with resonances in the wood, the function of the foam part is actually to lower air speed along the sides of frame. These create artefacts in the sound. I noticed a big improvement in the precision of the bass when I lined my frames with a foam not dissimilar to no-rez.
So, you might want to try it out. You can mount foam pieces temporarily with double sided tape or similar.
Looking forward to see your prgogress!
/The Priest
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The problem for many would be the added height which may not be ideal if you plan to build dual subs to set monitors on top of them. However, the monitors can perch on stands close to the subs, but you encounter another kind of clutter issue. Nevertheless, I prefer this approach and would angle monitors downward to compensate for the height. Just need longer speaker cables to reach up to the monitors.
Interesting that you made this point this way. Based on reading this forum for quite a while, I get the impression that it is actually a minority of people using these subs as monitor stands and the exception to the rule seems most often folks doing one of Danny's designs intended to integrate an upper and lower frequency section (like the V2, Super-V, Super-7). The nx-monitors and super-minis it seems were kits made up in retrospect to accommodate folks that needed (or wanted) to compromise to get as much sound in as little floor footprint as possible (accepting that there would be a meter of space to stash the amp on the floor behind the sub in any case because the subs are OB).
It is looking at what people have been mostly building/buying that brought me to surprised that someone hadn't done this sooner. I also think it is something to consider for Danny going forward if statement speakers like the line forces are going to be finished-production rather than kit speakers. Having a triple stack plus amp of height (effectively a quad driver height speaker) in a sub tower to go along with speakers like the line forces or nx-tremes for that matter I think would make a final product more in line with the priorities of people in the market for such speakers (where size of the room isn't an issue but reducing the number of boxes scattered on the floor aesthetically might be a higher priority).
Regardless, I still think this will be a very cool looking sub tower! :thumb: I've said it before and will say it again that I admire folks who can build really great stuff like this.
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Regardless, I still think this will be a very cool looking sub tower! :thumb: I've said it before and will say it again that I admire folks who can build really great stuff like this.
Thank you so much for your kind words. The creative burst I get from making this stuff provides a real lift to my day. I was inspired by some other people on here who have done versions of this with the amp integrated into a taller version so other people have done it, but I haven't seen many.
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Interesting that you made this point this way. Based on reading this forum for quite a while, I get the impression that it is actually a minority of people using these subs as monitor stands and the exception to the rule seems most often folks doing one of Danny's designs intended to integrate an upper and lower frequency section (like the V2, Super-V, Super-7). The nx-monitors and super-minis it seems were kits made up in retrospect to accommodate folks that needed (or wanted) to compromise to get as much sound in as little floor footprint as possible (accepting that there would be a meter of space to stash the amp on the floor behind the sub in any case because the subs are OB).
Yeah, since Danny has recently introduced several OB-style monitors, more people will likely use the subs as stands. Nevertheless, there's value in keeping subs as short as possible for practical reasons such as weight, mobility, WAF, and reduced sonic interference. It may also be a good practice to separate plate amps from subs to eliminate vibrations to the amp. With all that being said, I want to get in the queue to commission Russell to build a pair for me. 8)
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If there was interest, we might do something up with our triple kits ( turn into a dual with integrated amp section) or quads ( turn into triples with integrated amp section)..... ...... :scratch:
Danny has always suggested keeping the amps separate if at all possible so.....
jay
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If there was interest, we might do something up with our triple kits ( turn into a dual with integrated amp section) or quads ( turn into triples with integrated amp section)..... ...... :scratch:
Danny has always suggested keeping the amps separate if at all possible so.....
jay
Could always section off part of the amp chamber to be filled with sand or something. May also help with balancing, esp when all 3 drivers are facing forward. :scratch:
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If there was interest, we might do something up with our triple kits ( turn into a dual with integrated amp section) or quads ( turn into triples with integrated amp section)..... ...... :scratch:
Danny has always suggested keeping the amps separate if at all possible so.....
jay
I get and appreciate Danny's complete and total commitment to the highest possible quality of sound reproduction. We are all the beneficiaries of that. The other thing that I love about making the speakers ourselves is that we have the freedom to nudge things in directions that work best for us. I know that I do not have his ear and so I get to make my speakers based on his excellent design and electronics in a way that works for me. For me it is the best of both worlds, I get access to a first class acoustical/engineering mind, without which I would be completely lost and I get to put my own creative spin on it. I love that.
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Well, it is done! For now.
(https://www.audiocircle.com/image.php?id=217948)
When last I left you I had made a mistake cutting the dado. Here I am getting the replacement piece down to the exact size. Normally when I do a repair I do it before sanding and finishing. The sanding and finishing often help to cover up little inconsistencies in fit. Because I pre-finished the inside parts of the H frame I had produce a fill piece that was very precise in fit. I used a shooting board and jack plane to shave off tiny little bits until it was just right. If you are looking to take your woodworking to the next level mastering the sharpening and use of a hand plane can really help to get you there.
(https://www.audiocircle.com/image.php?id=217949)
The grain doesn't line up so its not perfect but its not too noticeable.
(https://www.audiocircle.com/image.php?id=217950)
(https://www.audiocircle.com/image.php?id=217951)
Next I had to plane the top and the bottom pieces of the H frame. They were too wide too go through my electric planer so it was a lot of hand work to get the boards flat.
(https://www.audiocircle.com/image.php?id=217952)
Then I glued in the front panel of the lower sub compartment. The panel is 1/4" cherry plywood glued on to 3/4" MDF. I couldn't account for wood movement going the other direction so this panel had to be inert. Something just occurred to me. I don't have any ventilation holes in the sub compartment. Is this something that is necessary? I didn't think of that at all until just now.
(https://www.audiocircle.com/image.php?id=217953)
Once I had my black painted MDF baffle in I cover it all in garbage bags so that it wouldn't get dusty. Cleaning saw dust off of flat black painted MDF never leaves it looking pure black. The discolouration that you see in the ends of the side pieces is the epoxy that I used to fill the checking in my boards. That part went pretty well and with careful placement of the boards there are very few places where you actually see it, especially from the front.
(https://www.audiocircle.com/image.php?id=217954)
This is the part that didn't work out so great and I may change it yet. I was concerned about attaching the top in a very solid way. I wanted something super solid as I knew the sub would end up being over a hundred pounds and I didn't want to pull the top off as I was moving it around. I came up with the idea of making purple heart dowels that I would glue and pound into the frame.
(https://www.audiocircle.com/image.php?id=217959)
I thought it would look nicer it my pegs had square tops so I rounded off about three-quarters of the the dowel and left the tops square. When I pounded the square end into the round hole it would push the circular opening into square in the cherry.
(https://www.audiocircle.com/image.php?id=217960)
This was my dry fit. I had done a sample using the same woods and it went really well.
(https://www.audiocircle.com/image.php?id=217961)
I guess the "square peg-round hole" saying has a basis in fact. Many of them worked pretty well but a lot of them twisted as I pounded them in leaving me with a result that does not look the way I was hoping. Once they were in I cut off the excess with a flush cut saw.
(https://www.audiocircle.com/image.php?id=217962)
(https://www.audiocircle.com/image.php?id=217963)
The other problem that I got was that my cherry split in some places.
(https://www.audiocircle.com/image.php?id=217964)
I was mostly able to take care of the splitting with cyanoacrylate glue, (Krazy Glue). It will wick into a crack and then a clamp closed it up so those ended up being no too bad.
(https://www.audiocircle.com/image.php?id=217965)
The next morning I attached the bottom using a far easier method. These are GRK screws. They are structural screws that I had used for making a deck, they hold like nothing else.
(https://www.audiocircle.com/image.php?id=217966)
I sanded and finished the top and bottom and I could install the amp and drivers. Thanks to Captain Hemo for the wiring instructions. They were a life saver.
(https://www.audiocircle.com/image.php?id=217967)
The quality of the bass is so much improved over my sealed sub. Far less boomy and more distinct and crisp
(https://www.audiocircle.com/image.php?id=217968)
I am using the high level inputs for now. I only have one line level output on my amp and my thought was to have my sealed sub on the line level and my OB sub on the high level. I have not turned the sealed sub on yet, I want to get a sense of the OB goodness before I try to integrate the sealed sub. We'll see, I may find that I do not need the sealed sub. My thinking is to have it for when we watch movies to help pressurize the room.
(https://www.audiocircle.com/image.php?id=217969)
I am so happy with this combination! If you have ever wondered about the efficacy of open baffle base, set your concerns aside. It is a remarkable way to listen to music. Thanks so much to Danny and the whole community here who have helped me along the way.
(https://www.audiocircle.com/image.php?id=217971)
Oh yes, the top! You thought I was just going to skip over that one? Here's what it looks like. I'm not happy with the way it looks but it is rock solid. I will live with it for a bit but I may cut it off or, more likely, cover it with a thin flat piece of cherry that will cover the whole top and protrude an extra ¼" all the way around. I think it will end up looking like a piece of trim. We'll see. I wasn't happy with the legs on my first set of speakers https://www.audiocircle.com/index.php?topic=171283.msg1831266#msg1831266 and I lived with them until I came up with good idea to replace them. Something will come to me, or one of you will have a brilliant idea :)
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Congrats. That is a stunning build.
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Turned out awsome man :thumb: :thumb:
Enjoy
jay
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Yes, once you hear what the servo OB subs are capable of, there's no going back to sealed boxes.
And really nice build!!
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Hey that servo sub turned out really nice. Everything looks really nice. :thumb: :thumb: