Hi Karl, What inspires you to increase the thickness of the baffle? I imagine that you want to raise the resonance? Notice that the Sachiko design has specific measurements for the region at the back of the speaker. If I understand correctly, Scott refers to this as the low pass chamber. Moving the speaker "proud" to the cabinet, it seems to me, changes the volume of the low pass chamber. Further, notice that the manner in which you chamfer the baffle may change. I have no knowledge base to judge the significance of these modifications. I imagine that the volume could be compensated with wood pieces. The literal dimensions of the low pass chamber, independent of volume, are apt to be significant as well. Scott, Dave, and Chris, and especially Scott are the design mavens. Maybe Scott will comment.
<<Notice that the Sachiko design has specific measurements for the region at the back of the speaker. If I understand correctly, Scott refers to this as the low pass chamber. Moving the speaker "proud" to the cabinet, it seems to me, changes the volume of the low pass chamber.>>
Well, those three sentences have deflated my idea. If nothing else, I think that energy needed to efficiency move the air mass in the first chamber would be radically changed- with uncertain implications in terms of the sound.
Thanks for the idea. I am not now inclined to change the actual design in this matter
To answer your question: I was trying to minimize resonance, and increase the rigidity of the drivers mount. Additionally, I wanted to give myself a little option of putting in a driver with a larger magnet in the future.
Well, those three sentences have deflated my idea. If nothing else, I think that energy needed to efficiency move the air mass in the first chamber would be radically changed- with uncertain implications in terms of the sound.
Thanks for the idea. I am not now inclined to change the actual design in this matter
To answer your question: I was trying to minimize resonance, and increase the rigidity of the drivers mount. Additionally, I wanted to give myself a little option of putting in a driver with a larger magnet in the future.
Feel free to add another layer... it is usually done as a supraBaffle. The original baffle will need to opened up considerably. The additional opening will be the extra volume you have added to the air cavity. Be prepared to add back this volume into the cavity. small loose blocks of wood (or somesuch) will work fine and aid in breaking up any cavity resonances.
dave
dave
Finding Finland or Russian plywood. ApplePly?
I am having problems finding high quality plywood from Finland or Russian in sizes that allow for the 72" sides for the Sachiko's in Salem, Oregon.
Salem has a population of 250,000 in the metro area, so I have decided to start calling Portland which has 3,000,000 in the metropolitan area and is only one hours drive to the north. I hope to find it there next week.
However, Lowe's has 9 ply birch plywood that looks fairly good. Some pieces have a slight cup to it, and I have seen a few voids- but I can hand select to remove those who have a cup. Would the few small voids rule that product out? The price is great ($40 a sheet) and I hope to put a veneer on the speakers at a later date.
Also, ApplePly is a product that I can probably find. It is 7 ply Birch and Alder. This plywood looks great I think, but the grade allows a few very small voids. I have read that someone made Sachiko's out of ApplePly- is he or she on this group now? Would a 7 ply sheet be enough (as opposed to the 13 plys of the Finnish Plywood)?
Karl
I am having problems finding high quality plywood from Finland or Russian in sizes that allow for the 72" sides for the Sachiko's in Salem, Oregon.
Salem has a population of 250,000 in the metro area, so I have decided to start calling Portland which has 3,000,000 in the metropolitan area and is only one hours drive to the north. I hope to find it there next week.
However, Lowe's has 9 ply birch plywood that looks fairly good. Some pieces have a slight cup to it, and I have seen a few voids- but I can hand select to remove those who have a cup. Would the few small voids rule that product out? The price is great ($40 a sheet) and I hope to put a veneer on the speakers at a later date.
Also, ApplePly is a product that I can probably find. It is 7 ply Birch and Alder. This plywood looks great I think, but the grade allows a few very small voids. I have read that someone made Sachiko's out of ApplePly- is he or she on this group now? Would a 7 ply sheet be enough (as opposed to the 13 plys of the Finnish Plywood)?
Karl
I doing a non audio project with maple plywood from home depot and once i cut it with my high quality blades i'm not finding any voids, just the few on the stock exterior 4'x8' edges. Still lacks the ply#'s of BB. Apple ply basically is the American version of BB.
This is what you want, $$ though - Appleply
This is what you want, $$ though - Appleply
Notice that there is optional tongue on panel A (2) for a speaker brace. Omitting the wood tongue would allow for a deeper speaker frame. In my case, I definitely plan to brace the speaker. I am considering cutting panel A without the tongue and then retrofitting adjustable braces. I am thinking of four points threaded into hex drive inserts with locking bolts. This way the speaker could be mounted on the baffle at appropriate torque and then the points adjusted for equal pressure at each contact on the speaker frame/magnet. Of course, once the final side panel is glued in place further adjustment of the speaker bracing would be trial and error through the speaker cutout. The same would be true for the wood tongue. I have nothing against the wood tongue other than I am trying to keep the cutting as simple as possible for whomever I contract to cut the wood.
You may have read earlier in the thread that I intend to use bamboo plywood. I am not recommending bamboo as it appears that I am a pioneer in this regard for Hiro/Sachiko and Chris is doubtful as to how things may come out. And, it is an expensive experiment.
In my case, I can source the 19 mm (19.05 mm) bamboo plywood from a warehouse located about 40 miles away. I have transportation lined up for the cost of gas and a cheap dinner. Other than that, I was looking at 18mm 4X8 Baltic birch from Staten Island at 71.00 per sheet and more than 200.00 shipping. I would rather spend the shipping cost on the wood itself and be true to the design dimensions with 19 mm.
I started this adventure thinking I would build a scaled down Sachiko to fit a 2" driver. This was naive of me and a good thing that Scott was an ocean away. I think I would have been smacked on the side of my head. Now I am hesitant to ad lib any part of the design; speaker brace and wood composition excepted.
MP9, IIRC, used 19 mm BB cut diagonally from a 5X5 sheet. I talked to a local woodworker who echoed what many folks have said; 19mm BB is next to impossible to source in 4X8.
Are you certain that the Appleply is only 7 ply? The 1/4 is listed as 5 ply and 1 1/4 as 21 ply. I would expect the 3/4" to be more than 7.
Appleply
It is comforting to have this option as I may have to go this route. I looked up bamboo, but that looks like it is more difficult to work. Carbide saws to buy, sharp edges, etc.
One option is the 5'x5' Baltic Birch. It may be difficult to get a cabinet maker to make it that way as there would be more handling needed to deal with the triangular pieces.
People have made these speakers out of MDF, but after going to all this trouble, I do not want to skimp on appearance.
Monday I will start looking in a 60 mile radius from Salem. Portland, and Eugene both could have it. There is a good chance I can find the 4'x8' there.
The next larger city than Portland is Seattle. I would hate to drive 4.5 hours to get three or four pieces of plywood. Seattle (a beautiful city) has the worst traffic I have ever seen- I hate driving in traffic jams.
Karl
It is comforting to have this option as I may have to go this route. I looked up bamboo, but that looks like it is more difficult to work. Carbide saws to buy, sharp edges, etc.
One option is the 5'x5' Baltic Birch. It may be difficult to get a cabinet maker to make it that way as there would be more handling needed to deal with the triangular pieces.
People have made these speakers out of MDF, but after going to all this trouble, I do not want to skimp on appearance.
Monday I will start looking in a 60 mile radius from Salem. Portland, and Eugene both could have it. There is a good chance I can find the 4'x8' there.
The next larger city than Portland is Seattle. I would hate to drive 4.5 hours to get three or four pieces of plywood. Seattle (a beautiful city) has the worst traffic I have ever seen- I hate driving in traffic jams.
Karl
Appleby Plys
On the website for Appleply, it looks like normal plywood has 7 ply in 3/4" and I would guess Appleply has around 13 ply. I think it was built as an alternative to Baltic Birch Plywood.
Karl
On the website for Appleply, it looks like normal plywood has 7 ply in 3/4" and I would guess Appleply has around 13 ply. I think it was built as an alternative to Baltic Birch Plywood.
Karl
How much wood glue for building Sachiko
Approximately how many ounces of wood glue are required to build a pair of Sachiko/Hiro speakers? Thanks for any comment.
I went to Lowe's tonight to buy jigsaw blades for cutting sheet aluminum. I am gearing up to build a pair of mono blocks. The salesman showed me a band saw. I asked how dangerous it was. He held up his hands to show me several missing parts from his fingers. He may be just the person to cut my bamboo plywood.
Approximately how many ounces of wood glue are required to build a pair of Sachiko/Hiro speakers? Thanks for any comment.
I went to Lowe's tonight to buy jigsaw blades for cutting sheet aluminum. I am gearing up to build a pair of mono blocks. The salesman showed me a band saw. I asked how dangerous it was. He held up his hands to show me several missing parts from his fingers. He may be just the person to cut my bamboo plywood.
Is The Fostex 206 Speaker Recessed On The Sachiko?
1) Is the Fostex full range speaker that will go on my Sachiko be recessed when it is installed on the face of the speakers?
2) If it is recessed, I assume that is it is recessed the 3.5 mm that is the thickness of the speaker rim- right?
Thanks-
Karl
1) Is the Fostex full range speaker that will go on my Sachiko be recessed when it is installed on the face of the speakers?
2) If it is recessed, I assume that is it is recessed the 3.5 mm that is the thickness of the speaker rim- right?
Thanks-
Karl
Source of Birch Plywood
Hi Loren,
I think that the ApplePly is probably better than the Baltic birch plywood. It is heavier by 20%, has no voids, and has a better face and back from what I have seen.
However, the cost is 25% higher, and I also think that I just could not handle the additional 20% in weight over Baltic Birch Plywood. That would have put the speaker weight at about 150 pounds each.
The cabinet manufacturer located a high quality birch plywood- but it is not Baltic brirch. It has a great clear face. I think the grade allows some small voids, but I saw two pieces of the plywood and they had no voids, and looked beautiful, so I went with that.
It is 11 ply instead of the 13 ply found in the ApplePly and the Baltic Birch, but it looks great, however, so I will see how it works.
I will pay for half of the speaker cost tomorrow to get the project going, and I will ask who makes this plywood is and the cost and let you know.
Karl
Hi Loren,
I think that the ApplePly is probably better than the Baltic birch plywood. It is heavier by 20%, has no voids, and has a better face and back from what I have seen.
However, the cost is 25% higher, and I also think that I just could not handle the additional 20% in weight over Baltic Birch Plywood. That would have put the speaker weight at about 150 pounds each.
The cabinet manufacturer located a high quality birch plywood- but it is not Baltic brirch. It has a great clear face. I think the grade allows some small voids, but I saw two pieces of the plywood and they had no voids, and looked beautiful, so I went with that.
It is 11 ply instead of the 13 ply found in the ApplePly and the Baltic Birch, but it looks great, however, so I will see how it works.
I will pay for half of the speaker cost tomorrow to get the project going, and I will ask who makes this plywood is and the cost and let you know.
Karl
"Light Weight
In spite of solid hardwood inner ply construction, ApplePly weighs only 10% more than conventional softwood plywood of the same thickness. A 3/4" 4’ X 8’ Panel weighs 68 pounds."
My 18 or 19mm(i forget), 5'x5' Baltic Birch weighs ~63lbs. I'd call that heavier.
I have found some very void free looking 4'x8' 3/4" Birch ply at Lowes which fits the description of what you got.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.