To all those fond of OB designs, who have built various iterations, what elements of the design or construction itself have you come to prefer? Or would consider must-have design elements or processes if you were building your next reference level OB speaker.
Assuming physical size, WAF, room limitations are not an issue.
Do you prefer no baffle, big baffle? Square baffle, or rounded or curved around speakers? Flat baffle edges or heavily rounded over? Open back, wings, sealed woofers? Hard wood/plywood/mdf/metal/alternative material?
For example...I've seen a number of variations on how the speakers/woofers are fixed to the baffle.
Some are screwed directly to baffle and stick out. Some recessed into a rabbit on the speaker opening to sit flush with face. Some mounted from the rear and have the speaker opening heavily chamfered. Some strung by suspensions and uncoupled entirely. All obvious designs someone made during the build/design process. But to what end for each of us?
Bottom line, are there designs you would never want to build again for some reason? Or elements you will always have.
What tricks have you picked up/mistakes you have made on your previous builds that you rely on to make the next one even better?
Assuming physical size, WAF, room limitations are not an issue.
Do you prefer no baffle, big baffle? Square baffle, or rounded or curved around speakers? Flat baffle edges or heavily rounded over? Open back, wings, sealed woofers? Hard wood/plywood/mdf/metal/alternative material?
For example...I've seen a number of variations on how the speakers/woofers are fixed to the baffle.
Some are screwed directly to baffle and stick out. Some recessed into a rabbit on the speaker opening to sit flush with face. Some mounted from the rear and have the speaker opening heavily chamfered. Some strung by suspensions and uncoupled entirely. All obvious designs someone made during the build/design process. But to what end for each of us?
Bottom line, are there designs you would never want to build again for some reason? Or elements you will always have.
What tricks have you picked up/mistakes you have made on your previous builds that you rely on to make the next one even better?
One problem with recessing drivers into a rabbit is that it can get quite bloody, and also the fur can muffle the sound. However, recessing them into a rabbet instead eliminates all of those problems.
Such a thing would usually be referred to as a dipole speaker. The requirements become much clearer and they are largely based on a consistency of dispersion.
Indeed, best baffle is no baffle.
exception: maybe a baffle for the bass, if the bass units max frequency are kept below where the baffle causes problems. If wood working skills are lacking, just use more bass units 🙂
drivers hanging,
drivers decoupled from each other.
exception: maybe a baffle for the bass, if the bass units max frequency are kept below where the baffle causes problems. If wood working skills are lacking, just use more bass units 🙂
drivers hanging,
drivers decoupled from each other.
A couple good ways around rabbeting is to do a front surface mount and then laminate a thin sheet of ply, underlayment etc on the front and or cover the panel in thick felt even with the front of the speaker frame. The felt looks good and helps with diffraction.
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Cheaper on Amazon. Only $39.95 there. Plus you will need a 1/4" spiral bit which is another $20 or so.
Works great for driver cutouts and flange rabbets as well.
I was reading this and wondering, wtf is he talking about haha. omg... Damn blood and fur.
It's when you try to get your open baffle to project evenly front and back, to understand it in more detail and move beyond leaving it to chance.
I guess I was just a little confused with your statement concerning the requirements becoming more clear.
I understand dipole design and certainly think it makes a lot sense with an OB. Seems to enhance the traits that OB are valued for.
I understand dipole design and certainly think it makes a lot sense with an OB. Seems to enhance the traits that OB are valued for.
Sometimes it only takes a simple constraint like that, and the more you look into it the more the answers come to you.. or to put it another way you don't have much choice 😉
The few I've built ended up sans baffles. They were completely free of coloration. The challenge is always going to be 200hz and down though. Demands on the drivers in that region are going to be huge if you like higher SPL's.
>Demands on the drivers in that region are going to be huge if you like higher SPL's.
Which is why OB is sort of an old man's speaker. I'm old and prefer quality over quantity - particularly in the SPL department. SPL definitely doesnt do for me what it did in my youth; I simply dont like loud music these days. Xmax? I'll never take it there... Maybe if it was a 6" in an H frame.
Which is why OB is sort of an old man's speaker. I'm old and prefer quality over quantity - particularly in the SPL department. SPL definitely doesnt do for me what it did in my youth; I simply dont like loud music these days. Xmax? I'll never take it there... Maybe if it was a 6" in an H frame.
at 200Hz the wavelength is almost 6 feet. so you can have a decent sized baffle before it interferes at all with the dipole pattern... and can you really have true dipole radiation anyway below the rooms Schroeder frequency? give the poor woofer a little help.
also a very narrow rectangular baffle on the midrange and tweeter can help with its low end while actually improving the response by creating a variety of front/backwave path lengths. a cone driver is a circular baffle in itself and that creates maximum diffraction ripple. planar drivers are great for dipoles because they are already rectangular baffles and have a back wave unimpeded by a basket.
something you can try is suspending each driver/baffle assembly from cables or bungees to reduce reaction force vibration from the cone movement. then you can have the ideal acoustic baffle shape without structural resonances. this concept was quaite the rage here several years ago, search for "naked swingin' dipoles" or something like that...
separate minimalist baffles for each driver, all suspended independently from a frame would be my preferred design.