Just saw this sale, thought it might be use full. https://www.madisoundspeakerstore.c...g/solen-18.0-mh-perfect-lay-inductors-16-awg/ still pricey but better than most air core offerings.
Jeremy
Jeremy
Found a local woodworking store with 30"x60" 3/4" Baltic Birch panels - picked out two very nice finish ones. $140, but all the reviews I've been reading on best material for speakers seems to be this BB 3/4" plywood (it sure looks nicer that the stuff I looked at Home Depot!). Figure it would be worth the spend if I plan on keeping these a while. The extra size allows me to use the leftover for the two wings and the base too! Now to find something to practice using a router on before I mess up these $$ panels. Wish the darn tweeters were round instead of rectangle...
Not clear what you want to do?
Eliminate the back wave or kind of smoothing it by applying some treatment to the back of the panels?
Eliminating the back wave defeats the purpose of an OB speaker.
As its well known there are nulls on the sides and if you eliminate or reduce the back wave there's only the front left. So the sound will be one dimensional, kind of flat, lacking a lot a spatial clues present in a music performance.
Smoothing the back wave with some acoustic treatment hardly ever works as your room has a much greater influence on the overall sound.
Maybe clarify.
Cheers
I asked this a few years back but never got a clear answer. Went so far as buying a bunch of material to glue to the back of the baffle but it never got installed after a few experiments with paper towels.
Basically a bunch of paper towels were placed on the rear of the baffle in various locations. Not quite what gluing the entire back side would do but an approximation. It definitely sounded different but it wasn't necessarily sounding better. At the time the Ultras were sounding kinda mellow and the paper towels made them even more mellow.
You'd expect the glued material to sound different than the paper towels but there's no way of knowing without committing to the change. But the paper towels are a cheap, easy experiment.
Let us know what you do and how it sounds.
True, but my understanding is that both the tweeter and woofer should be flush mounted for best sound?
And sorry if I missed this, but on the back side of the tweeter hole, one should open up the backside to let the tweeter breathe, say a 6" cutout, but how deep should this be? 1/4"?
I did relieve the backside of the tweeter holes. And my woof was flush. You could trace with a pencil around the rectangular tweet mounting flange, cut the outline with sharp utility knife and use a chisel to get it flush. I chose not to. Would have to measure to tell if it makes a difference. Good luck with your project!
I was more concerned with resonance and perhaps removing anything that might detract from the sound coming from the front of the speaker. Like @barryso said, the answer is not clear.
Spray-on 'Truck bed liner' was mentioned early on as a possible treatment to the baffle rear. As was 'do nothing'.
I think I decided that if bed liner was good then some sort of acoustic treatment would be better - without taking into account the effect that would have on the backwave of an Open Baffle arrangement
my bad.
I think I will leave it off as suggested - I am sure my less than optimal listening space will present more issues than the back side of my baffle.
Thanks for keeping me on track. Richard
Spray-on 'Truck bed liner' was mentioned early on as a possible treatment to the baffle rear. As was 'do nothing'.
I think I decided that if bed liner was good then some sort of acoustic treatment would be better - without taking into account the effect that would have on the backwave of an Open Baffle arrangement
my bad.I think I will leave it off as suggested - I am sure my less than optimal listening space will present more issues than the back side of my baffle.
Thanks for keeping me on track. Richard
dagger nc the optimum dimension for brace is 2.5 x the thickness of the material you want to use, so for a one inch thick material the brace would be 2.5 inches wide, mount on the one inch side Less width less stiffness more width minimal stiffness gain. Remember you don't want to take up any more cabinet volume than is necessary so this ratio buys the best compromise for stiffness for the quantity of material used.
Sorry, I meant that in terms of the brace taking up space in the OB volume. So does this mean adding a brace turns the volume into a negative number, and if so, how does that affect performance? I mean, it makes no intuitive sense that a brace would make a bit of a difference IN TERMS OF cabinet volume. It might have an impact for other reasons, but cabinet volume? Please help me understand.
Carl,
The OB volume is just thin air.
There is no such thing as volume in an Open Baffle.
There is no cabinet at all, just a flat plank of wood where the drivers are mounted, and that plank separates the front wave from the back wave.
Due to the nature of OB speakers the sides are nulls and the the sound output is mostly from the front and back, sort of figure of 8 response.
Forget all about closed boxes, vented boxes, and so on, this is a different beast.
Braces in OB are to add structural strength in order to decrease vibrations and they can have any form and shape and go in any direction that is practical.
Maybe I misunderstood you. If so ignore my rumble.
If that's the case you'll need to clarify what exactly is the issue so someone more articulate can answer your question.
The OB volume is just thin air.
There is no such thing as volume in an Open Baffle.
There is no cabinet at all, just a flat plank of wood where the drivers are mounted, and that plank separates the front wave from the back wave.
Due to the nature of OB speakers the sides are nulls and the the sound output is mostly from the front and back, sort of figure of 8 response.
Forget all about closed boxes, vented boxes, and so on, this is a different beast.
Braces in OB are to add structural strength in order to decrease vibrations and they can have any form and shape and go in any direction that is practical.
Maybe I misunderstood you. If so ignore my rumble.
If that's the case you'll need to clarify what exactly is the issue so someone more articulate can answer your question.
Thanks Stanislav. I was commenting on a post above (by moray james) that stated "Remember you don't want to take up any more cabinet volume than is necessary" That post was talking about sizing a brace and hinting that somehow a larger brace would take up volume in the OB "box." I was simply asking how taking up volume in an OB mattered...given what I already know about OBs, i.e. that they don't have volume. But no-one seems to get the question or I'm missing something obvious. I'll drop it.