The base and feet are finished, and the final coat of varnish has been applied. All that is left is to reinstall the drivers and make a few quick FR scans to make sure nothing changed.
I verified that there was no change in impedance or on-axis frequency response in either speakers. By tomorrow the varnish will have cured for 3 days, so I can do a final polish and wax, then I deliver them to my friend.
I have been listening to them all day while I clean up my shop. I like these speakers, and I don't have anything to add to what I said in post #521 https://www.diyaudio.com/community/...ivers-a-new-3-way-project.413182/post-7798507
My friend chose the veneer, sapele. The paper backing and PSA adhesive layer seemed thicker than other PSA veneers I have recently used, and the paper adhesive is a lighter color than the sapele wood, so the glue lines are more prominent than I would like. There is nothing to be done about it now...
I have been listening to them all day while I clean up my shop. I like these speakers, and I don't have anything to add to what I said in post #521 https://www.diyaudio.com/community/...ivers-a-new-3-way-project.413182/post-7798507
My friend chose the veneer, sapele. The paper backing and PSA adhesive layer seemed thicker than other PSA veneers I have recently used, and the paper adhesive is a lighter color than the sapele wood, so the glue lines are more prominent than I would like. There is nothing to be done about it now...
Jim, they look good... and wow, that is one tidy workshop!
Thanks for the kind words ... It just looks tidy in the photos.
I used a lower grade of plywood because I knew I was going to veneer them. If the plan was to use a natural finish on the plywood, I would have used Baltic birch or bamboo core plywood so the cut edges would be decorative. I also would have been much more careful about glue smears, dents, scratches, and screw holes. In the photos in post # 463, you can see the many blemishes in the raw cabinet which would have made it impossible to achieve a high quality finish. https://www.diyaudio.com/community/...ivers-a-new-3-way-project.413182/post-7788145
I personally think it is more effort to build with a natural Baltic birch finish than it is to just veneer at the end. There is a lot of effort needed to maintain a pristine exterior surface and extremely crisp cut edges, and it affects the whole workflow of the cabinet construction... how I align and clamp, and what kind of adhesive I use, etc. The most difficult aspect of veneering is bevels. The 90 degree edges are very simple.
j.
I prefer these, it goes on after the finish. We used them in the refinishing shop I worked in 50 years ago. Also spit and finger fudge does miracles on scratches that would mysteriously appear 5 minute before delivery.
https://www.minwax.com/en/products/maintenance-repair-tools/blend-fil-pencil/
https://www.minwax.com/en/products/maintenance-repair-tools/blend-fil-pencil/
Here is the last bit of performance plots for this project. It is not ground breaking performance, but it is respectable performance.
I put together a design document, which is attached below. However, if I were to build another one, I would make some changes.
First I would change the shape of the midrange sub-enclosure. I would make it wider so there is more clearance around the SB15CRC driver. I believe some of the unevenness around 2k is a result of the driver being tightly constrained on three sides.
Second, I would make the base/plinth integral with the cabinet. The sides and baffle would span the entire 42" height, but the floor would be internally elevated by 5". The crossover would still be mounted in the base, separated from the speaker interior. The veneering and finishing of the cabinet was unnecessarily complicated by having a separate small box under the speaker.
Third, I would use the aluminum cone DSA270-PR passive radiator instead of the paper cone DS-270PR. I think the black aluminum cone would look better. I chose the DS270-PR because it had a very slight advantage in the shape of the bass curve... but after including the effects of low-pass filter gain on the woofer, there is no meaningful difference between the DS270 and DSA270.
j.
First I would change the shape of the midrange sub-enclosure. I would make it wider so there is more clearance around the SB15CRC driver. I believe some of the unevenness around 2k is a result of the driver being tightly constrained on three sides.
Second, I would make the base/plinth integral with the cabinet. The sides and baffle would span the entire 42" height, but the floor would be internally elevated by 5". The crossover would still be mounted in the base, separated from the speaker interior. The veneering and finishing of the cabinet was unnecessarily complicated by having a separate small box under the speaker.
Third, I would use the aluminum cone DSA270-PR passive radiator instead of the paper cone DS-270PR. I think the black aluminum cone would look better. I chose the DS270-PR because it had a very slight advantage in the shape of the bass curve... but after including the effects of low-pass filter gain on the woofer, there is no meaningful difference between the DS270 and DSA270.
j.
