Cut the circles in the horizontal braces this morning before work. This is looking so pretty I don't want to cover it all up!
DIY flush mount speakers
Originally posted at johnlsayers.com, topic 16933.
Maybe you could make the front baffle from glass, instead of wood? :) Would be great acoustically! Just not so great on your pocket...
- Stuart -
$21/sq.ft. x 2.9 sq. ft. x 2 for 3/4" glass, that would be $120. I don't know how I would cut the holes for the speakers though, and who knows what kind of a rats nest the crossover is going to be.
I plan on cutting the font baffles tonight. That is the highest stress part for me in building a speaker, especially with baffles this big. One screw-up and the piece is trashed and you have to start over.
If you did do glass, you'd probably have to have it custom made... and it would be rather more expensive. Probably wood is the best choice. Pity that all your neat workmanship won't be visible, though!
- Stuart -
Baffles cut for the tweeters and mids. No major mistakes. Only have the woofers to go.
I actually cut the baffles without screwing them up! I don't think I have ever done that before.
Nice! It's going pretty fast, too. I'm dying to see how it turns out!
- Stuart -
I hope to be doing measurements on Sunday or Monday. Hopefully I can finish the assembly tonight, then fit them to the wall tomorrow. Then I have a very busy Friday and Saturday where I'm probably not going to get anything done.
Here is the box model. The speakers have a volume of 108L. The ports are tuned to 33HZ. Which is perfect for a 3" (inside diameter) piece of 7" of PVC pipe!
Nice to have something in those big holes!
The measurement set up.
Pictures from measurements last night. Still have a bit of a learning curve. My mic seems to not be responding well above 9k. I don't think it should matter in the crossover design though.
Tweeter response
Mid response
Woofer response
The response graphs are made using both nearfield and farfield measurements and blended using Charlie Laub and Jeff Bagby's FRD Response Blender. You can download the program and a paper on the methodology used for these measurements here http://audio.claub.net/software/FRD_Blender/Blender.html
Here is the response graph for the crossover that I have designed. It is flat within 3db, but that jag at 200hz kind of bugs me, but it is in the measurement.
I put together a crossover with parts that I had on hand. Some of them weren't exact (I used a 3uh inductor instead of a 3.7uh for example) I unwound some coils that I had for exact values and none of the capacitors were the exact value, but it made music and sounded pretty good! Here is a measurement of the speaker. My measurement microphone drops off severely above 10k.
The layout of the crossover and the build of the crossover.
The measurement system.
Listening nirvana. I had no idea that these would sound this good!
It looks fantastic, Eric! Congratulations! And I'm surprised at how fast you managed to put that all together, with such skill and craftsmanship! (Of course, I do understand all the weeks of work that went into the design first!)
Can't wait to see the final REW data, after all your tweaking is finished.
- Stuart -
This is stereo from the mix position. I have never heard imaging like this before!
Now I have to learn how to measure a room.
Especially considering how long the studio has taken. :yahoo:It looks fantastic, Eric! Congratulations! And I'm surprised at how fast you managed to put that all together - Stuart -
AHhh! Now we are talking about one of my favorite subjects! :) If you are interested in doing it the way I normally do (using REW), then PM me, and I'll send you the instructions I normally give to my paying customers on how to do that. - Stuart -Now I have to learn how to measure a room.
I had been measuring with the output from my laptop. I just connected my soundcard and did some more measurements. Let's just say my measurement mic does not have problems above 10k.
Here is the new nearfield measurement of the speaker.
Here is measurements for each speaker individually from the mix position.
Here is a mono test signal from both speakers from the mix position.
I think when I start doing REW stuff I'm going to find issues at 80hz.
I wonder how much not having a bezel on the right speaker effects the measurements.
Your graphs at the mix position look pretty much they way I'd expect from a typical room. What treatment do you have in there right now?
I'd love to see the measurements taken in REW, so I can see all the other things that are happening, not just the frequency response. That's important, of course, but only a small part of the picture.
I would imagine that it is having a quiet significant effect, especially in the low end. - Stuart -I wonder how much not having a bezel on the right speaker effects the measurements.
Sorry this took so long. The picture below show all of the treatment that I have for the room.
The wedges on the sides are a hard surface facing the mix position but are filled with rockwool which is open facing the speaker. I have two similar wedges on the ceiling angled to reflect to the back of the room, but with the front open and filled with rockwool. The back wall has 1/2" drywall with 4" of rockwool and hangers as shown.
I made an error on the dimensions, it should be 17'6" width 11"6". In front of the mix position, the height is 7'6" behind it is 6'8".
I am planning on doing measurements tonight. Should I post those here, or go back to my original studio build thread?
Thanks again for all of your help!
I would suggest posting them here, and putting a link at the end of your build thread that leads here. Or do it the other way around: Post them on the other thread, and put a link here, at the end of this one, going back to your build thread. If you want, I can lock this thread after you post the link to the other one, so nobody else can mess it up with additional comments: they would have to go to the other one to comment. - Stuart -I am planning on doing measurements tonight. Should I post those here, or go back to my original studio build thread?