You have to wait Crescendo until the data is confirmed cause I have two different pwr compr. values of this driver.
Excursion is directly coupled to SPL and power not. So less excursion (because of pwr comp) results in less SPL.
Make sure your bracing is enough (and made well) cause that thing gets "swollen cheeks"Yes it does. If someone else doesn't jump on this I might be the first to build it within the next couple weeks!
Martin any chance you wanna make this reallyyyyy easy and include a cut sheet as well? (well cut sheets)
(and that is going to cost you a couple of dB's). The problem I brought up in post # 309 was caused by bracing that came loose.
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One in the middle but use my second suggestion as guideline cause it can use support over the whole length at the back (don't forget to cut out the wholes). Btw, you would be the first as ours are not the same as Xoc1's (ours are similar and -3dB at 36Hz but 2dB in SPL lower
)
Maybe -
Can you give me some guidance on what allowance you think is reasonable for the saw cuts.
Would you be cutting the mitres with the saw bench?
Also I take it that you are happy with a simple glued and screwed box and you are not rebating the sides?
This is one of the problems with providing a cut sheet, different people have different ideas, skills, and techniques for construction.
It would be very easy for instance to generate some DXF files to allow the sides to be rebated with a CNC Router.
That would probably be my choice!
Thanks for all the positive comments from everyone, I am very busy at the moment and it looks like that might be the case for at least another couple of months. However I am very happy to continue to develop these designs within the forum.
The current design is based on the inputs of many forum members and as such I am not really in a position to claim ownership of any part of it. I,m enjoying bringing all the different knowlege skills together.
m R g S r when you are ready to build let us know and we can start a new thread and get all the relevant information together in one place!
I would love to Use the Cnc router that I don't have lol so yes glued and screwed is the only way for me to do it.
For cutting allowance, it doesn't really matter as the design isn't single sheet based. So whatever the allowance is is fine with me.
All I have is a table saw and a router drill press hole saws etc. No crazy, expensive, Computer driven tools.
For cutting allowance, it doesn't really matter as the design isn't single sheet based. So whatever the allowance is is fine with me.
All I have is a table saw and a router drill press hole saws etc. No crazy, expensive, Computer driven tools.
Yes, hollow your braces by quite a good amount - the more 'solid' they are, the more low corner you sacrifice.
Btw, you would be the first as ours are not the same as Xoc1's (ours are similar and -3dB at 36Hz but 2dB in SPL lower
What are you referring to when you say, "ours" by the way?
If I say 'me' instead of 'ours' I'm getting poked tomorrow by annoying ol' people who will claim I steal their credits
That only helps for the outer panels, the inner planels which are all 535mm wide would still be unbraced. If you don't care about weight, then sure go crazy and add steel plates to the outside of the box lol but for something that is supposed to be "semi" portable i think metal bracing would add a bit too much weight....
For initial construction, i think that adding the internal bracing along the entire length of the path down the center seems like a good option. I will add as many holes as possible without weakening the braces too much. Then in the future I could always add to the outside. Or I could use 1" ply for the outter panels and 3/4" (sorry..err..18mm) for the inners
For initial construction, i think that adding the internal bracing along the entire length of the path down the center seems like a good option. I will add as many holes as possible without weakening the braces too much. Then in the future I could always add to the outside. Or I could use 1" ply for the outter panels and 3/4" (sorry..err..18mm) for the inners
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Crescendo, our cab is based on an extra folding to Jbell's concept (see one sheet challenge) and kept everything as symmetric as possible for easy building.
MrGsR, going full inch panels doesn't make a big difference as the structure of the Beechwood isn't more dense. If really want something dead you need sandwich/layering style of panelling with a thin layer of bitumen in between. For instance 9mm multiplex beech + 1mm Bitumen + 9mm multiplex of another kind of wood.
(Btw, we sometimes 'paint' the insides with liquid rubber which doesn't smell if the cab is standing in full sun)
MrGsR, going full inch panels doesn't make a big difference as the structure of the Beechwood isn't more dense. If really want something dead you need sandwich/layering style of panelling with a thin layer of bitumen in between. For instance 9mm multiplex beech + 1mm Bitumen + 9mm multiplex of another kind of wood.
(Btw, we sometimes 'paint' the insides with liquid rubber which doesn't smell if the cab is standing in full sun)
I think you are mixing a few things:
1.) Padding works by absorption of soundwaves trough air. The absorption material(s) transfer the energy from the sound waves into heat (friction). Exception; if pressurise padding between two solid materials it becomes also a contact absorber.
2.) Rubberising works by absorbing internal contact sounds trough materials. Sheets of wood start to vibrate like a membrane. To suppress this vibration you can use several techniques. It wont work as good as the 'sandwitch' method but yes it does make a difference.
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Well in the car audio world second skin audio makes some of the best stuff for sound deadening. I could try their spectrum stuff....i have used their products in the past and they are excellent! pricey, but excellent.
Second Skin Spectrum - Noise & Vibration Sound Deadener Coating
or the sludge which is thicker...
http://www.secondskinaudio.com/sound-deadener/spectrum-sludge.php
Second Skin Spectrum - Noise & Vibration Sound Deadener Coating
or the sludge which is thicker...
http://www.secondskinaudio.com/sound-deadener/spectrum-sludge.php