I've been thinking about building an open baffle speaker using a very heavy natural wood. I love the texture, color and feel of natural wood, and OB is a lot easier than building a box.
Today, I had the extreme pleasure of handling an ipe board for the first time in my life. Holy ****! It is 40% heavier than hard maple, and two and a half times as hard. I was outside, where the temperature was around 30*F, and picking up this board just sucked the heat out of my hands. It felt more like metal than wood.
Link to detailed description of ipe
Link to description of hard maple for comparison
I can buy ipe heartwood boards that are up to 2" thick and 12" wide from my local hardware store. Two 2" x 12" x 36" baffles will set me back about $80. Based on a density of 62 lbs/sq foot, the baffles will weight around 30 lbs each. Drivers would be the Vifa XG18 and Seas 27 TBFC/G.
I was thinking about standing them up on a solid chunk of granite. I have a friend who is a master tile setter, who could shape and polish the granite any way I need.
The only thing holding me back is my fear for my tools. I've recently spent about $100 on carbide router bits, and I'm afraid this one project could ruin them all.
I tried searching the forums for other projects like this, but couldn't find anything. I'd really like some advice before I embark on this project, especially from anyone who has worked with ipe, or other extremely hard woods.
Dan
Today, I had the extreme pleasure of handling an ipe board for the first time in my life. Holy ****! It is 40% heavier than hard maple, and two and a half times as hard. I was outside, where the temperature was around 30*F, and picking up this board just sucked the heat out of my hands. It felt more like metal than wood.
Link to detailed description of ipe
Link to description of hard maple for comparison
I can buy ipe heartwood boards that are up to 2" thick and 12" wide from my local hardware store. Two 2" x 12" x 36" baffles will set me back about $80. Based on a density of 62 lbs/sq foot, the baffles will weight around 30 lbs each. Drivers would be the Vifa XG18 and Seas 27 TBFC/G.
I was thinking about standing them up on a solid chunk of granite. I have a friend who is a master tile setter, who could shape and polish the granite any way I need.
The only thing holding me back is my fear for my tools. I've recently spent about $100 on carbide router bits, and I'm afraid this one project could ruin them all.
I tried searching the forums for other projects like this, but couldn't find anything. I'd really like some advice before I embark on this project, especially from anyone who has worked with ipe, or other extremely hard woods.
Dan
Dan,
That's some serious wood. Don't know if it makes any difference, but here in the NW with all the rain and flooding, you should be aware that Ironwood (and it's evil twin, Ironbark) don't float. So if the valley floods, it's a real bad idea to grab your speakers and head out the door.
Best Regards,
TerryO
That's some serious wood. Don't know if it makes any difference, but here in the NW with all the rain and flooding, you should be aware that Ironwood (and it's evil twin, Ironbark) don't float. So if the valley floods, it's a real bad idea to grab your speakers and head out the door.
Best Regards,
TerryO
About 25 years ago I helped a friend build a 45 foot Alden Malibar Schooner. We used Ironbark for the Caprail, as Teak was not only too expensive, but not nearly as tough. We did indeed go through a lot of blades, but we were doing a lot of cutting as every piece had to follow the contour of the hull. Sharpened a lot of plane blades too.
Workboats often used Ironwood for propeller shaft bearings due to it's hardness and because it also has a natural waxiness that works well as a bearing. Ironbark is darker and has a slightly stringy grain structure that was often used on wooden boats to protect the hull planking from damage from the anchor and tackle. You may have seen those vertical boards at the bows of workboats and wondered what they were.
Best Regards,
TerryO
Workboats often used Ironwood for propeller shaft bearings due to it's hardness and because it also has a natural waxiness that works well as a bearing. Ironbark is darker and has a slightly stringy grain structure that was often used on wooden boats to protect the hull planking from damage from the anchor and tackle. You may have seen those vertical boards at the bows of workboats and wondered what they were.
Best Regards,
TerryO
Tough stuff, that ironwood. I've played around with scraps, but never big chunks.
However, I can attest to dense wood being good for speakers. Back in the 80's we used to use plywood called "Nantex" that was the heaviest, densest, most difficult to cut and drill wood I've ever seen. Like your comment about ironwood feeling more like metal than wood. Nantex plywood was like working with non-resonant steel. Thick steel.
The acoustic results were pure magic. Speaker boxes that had no box sound. Not dead like some materials, just no real sound of its own, or at least no objectionable sound. Don't quite know how to describe the difference between dead and no coloration, but that's how it was.
If your ironwood can do that, and it probably can, it's going to make you very happy. After you forget about how hard it was to work, of course.
However, I can attest to dense wood being good for speakers. Back in the 80's we used to use plywood called "Nantex" that was the heaviest, densest, most difficult to cut and drill wood I've ever seen. Like your comment about ironwood feeling more like metal than wood. Nantex plywood was like working with non-resonant steel. Thick steel.
The acoustic results were pure magic. Speaker boxes that had no box sound. Not dead like some materials, just no real sound of its own, or at least no objectionable sound. Don't quite know how to describe the difference between dead and no coloration, but that's how it was.
If your ironwood can do that, and it probably can, it's going to make you very happy. After you forget about how hard it was to work, of course.
I believe, JohninCR must have quite extensive experience in working with very hard woods. Look for his nick here and at the OB circle at http://www.audiocircle.com/circles/index.php?board=90.0
TerryO - thankfully I live on a hill, so when Rainier errupts and buries Seattle under 60 ft. of mud my speakers will be spared. If they are buried, my hope is they will someday be excavated and enjoyed by future civilizations
panomaniac - I'm aiming for a very simple design, so I don't have much cutting to do. Three cuts with a circular saw, four cutouts with my router, and lots of rounding with my router.
Rudolf - thanks for the tip, going to search right now.
Anyone know if normal wood glue is sufficient for bonding ipe?
Dan
panomaniac - I'm aiming for a very simple design, so I don't have much cutting to do. Three cuts with a circular saw, four cutouts with my router, and lots of rounding with my router.
Rudolf - thanks for the tip, going to search right now.
Anyone know if normal wood glue is sufficient for bonding ipe?
Dan
I've used Machiche (called almendro here), which is almost as hard and heavy as Ironwood. The difficult part is getting it ready for a finish. Sanding, even with a belt sander, is all but useless. It will be hard on your tools too. Note that the 62lbs is per cuft, so your baffle won't be nearly as heavy as you think. You may want to consider isolating the woofers from the baffle with a magnet mount.
Being able to use real wood is one of the advantages of OB. Great grain and dried without cracking in a softer wood is what I look for now. Here's something I built recently. The baffle is Cenizaro and the driver magnet mounts are almendro for the extra rigidity where it counts.
Being able to use real wood is one of the advantages of OB. Great grain and dried without cracking in a softer wood is what I look for now. Here's something I built recently. The baffle is Cenizaro and the driver magnet mounts are almendro for the extra rigidity where it counts.
An externally hosted image should be here but it was not working when we last tested it.
pinkmouse - thanks for the tip. Althought I've never used it before, Gorilla Glue looks to be easily available.
johninCR - Nice speakers, is that the natural color of the wood? I do have a belt sander, and the boards are already pretty smooth, so I hope I can get a smooth finish. I'm not sure exactly what kind of finish to use yet. My general preference is something that will not change the natural color of the wood, and will enhance the grain.
This project hit a major snag yesterday, scoring a very low WAF. She doesn't like the idea of 12" wide baffles in our smallish apartment. I ordered the Vifa XG18 woofers anyway, and will not experiment with designing some smaller baffles.
Dan
johninCR - Nice speakers, is that the natural color of the wood? I do have a belt sander, and the boards are already pretty smooth, so I hope I can get a smooth finish. I'm not sure exactly what kind of finish to use yet. My general preference is something that will not change the natural color of the wood, and will enhance the grain.
This project hit a major snag yesterday, scoring a very low WAF. She doesn't like the idea of 12" wide baffles in our smallish apartment. I ordered the Vifa XG18 woofers anyway, and will not experiment with designing some smaller baffles.
Dan
Even a belt sander will do next to nothing and wear out a lot of belts in the process. Try a cabinet scraper, which is supposed to be better anyway. Mine got significantly darker with only linseed oil. The only thing I've found that doesn't darken is nitro laquer, but I don't have a spray rig. I'm negotiating with a guitar maker to give me some lessons about finish to do things right. I have several real wood speaker projects waiting for a proper finish.
Ipe is indigenous to the area in Brazil where I grew up. I am very familiar with its three varieties, purple, yellow, and white, that you just can’t miss when in bloom. Because it is so abundant and cheap, despite advice to the contrary from experienced carpenters, I built a pair of bookshelf speakers using Ipe many years ago and here is what I have learned. The cutting tools MUST be carbide tipped and even straight cuts will overheat and burn the wood. Rip with 24 TPI and cross-cut with 40 TPI blades.
If you clean the joint surfaces with acetone, white or yellow PVA glue will do the job. If you want to preserve the look of the wood, like I did, the only product that yielded a good looking finish and remained stable was clear nitrocellulose lacquer. Once again, before applying the first coat, clean the surfaces with acetone.
If you clean the joint surfaces with acetone, white or yellow PVA glue will do the job. If you want to preserve the look of the wood, like I did, the only product that yielded a good looking finish and remained stable was clear nitrocellulose lacquer. Once again, before applying the first coat, clean the surfaces with acetone.
Attachments
johninCR - by spray rig, are you talking about an air compressor and paint sprayer? I do have one of those, although I've never used it to apply wood finish.
grimberg - thanks for the advice. I'll experiment with some smaller pieces first, to get a feel for it, and see if I can even handle this type of project.
maxro - I'll admit that I'm inexperienced when it comes to OB, but I don't believe 12" is too small when the driver only has to cover 200hz - 2khz. I was looking for advice on working with hard woods, as there are already many many threads about OBs I can read.
Here are some modesl I ran using The Edge, on a 10" x 40" baffle.
I designed a baffle with a peak unpurpose, as I think it will be easier to deal with one peak in the crossover, rather than many smaller ones.
Dan
grimberg - thanks for the advice. I'll experiment with some smaller pieces first, to get a feel for it, and see if I can even handle this type of project.
maxro - I'll admit that I'm inexperienced when it comes to OB, but I don't believe 12" is too small when the driver only has to cover 200hz - 2khz. I was looking for advice on working with hard woods, as there are already many many threads about OBs I can read.
Here are some modesl I ran using The Edge, on a 10" x 40" baffle.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I designed a baffle with a peak unpurpose, as I think it will be easier to deal with one peak in the crossover, rather than many smaller ones.
Dan
owdi said:
Ok, he didn't ask for oppinions as to the suitability of said baffle size. I was just thinking that it is our duty to save a fellow DIYer from spending $80 on exotic wood and killing several router bits just to find that his narrow OB's cancellation results in zero bass response. Anyway, it seems a moot point as WAF has over-ruled.
edit: Above was response to Grimburg. I can't seem to quote from posts on seperate pages.
Re: Re: Thinking about building an OB using ironwood (ipe)
and I really appreciate the advice. It does have me doubting my ability to complete this project, I may chicken out and go with something easier to work with.
That is too true to be funny. Build a speaker with low WAF and the SNR goes way up, as you can't hear the music over the complaining in the background.
maxro - some more details. This OB is only for the midrange. The bass will be handled by a pair of Dayton Reference 12" woofers, which should easily sound great up to 200hz.
...and now the W is pulling me away to go shopping.. great.
Dan
grimberg said:
We gave him the advice he asked. He did not present the project or put it in discussion.
and I really appreciate the advice. It does have me doubting my ability to complete this project, I may chicken out and go with something easier to work with.
panomaniac said:Maybe WAF is stronger than wood. Even Ironwood.
Can we build speakers out of WAF?
That is too true to be funny. Build a speaker with low WAF and the SNR goes way up, as you can't hear the music over the complaining in the background.
maxro - some more details. This OB is only for the midrange. The bass will be handled by a pair of Dayton Reference 12" woofers, which should easily sound great up to 200hz.
...and now the W is pulling me away to go shopping.. great.
Dan
Re: Re: Re: Thinking about building an OB using ironwood (ipe)
Well, Owdi, that should work. If you have 12" woofers, then they dictate baffle with, no?(Or, are they firing sideways?) You might as well increase baffle width from 10" to 12" to get mid-bass extension just a little lower.
I'm new to open baffles, too and just didn't want you to be dissappointed after a lot of work. Remember courrigated cardboard is your friend when it comes to OB prototyping.
owdi said:
Well, Owdi, that should work. If you have 12" woofers, then they dictate baffle with, no?(Or, are they firing sideways?) You might as well increase baffle width from 10" to 12" to get mid-bass extension just a little lower.
I'm new to open baffles, too and just didn't want you to be dissappointed after a lot of work. Remember courrigated cardboard is your friend when it comes to OB prototyping.
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