DIY Open Baffle Info Needed

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#61
Like others have said, build test baffles first, before spending cash on finishing. I had bought 50" long butcher block countertops to do mine, as I wanted a look like my old Magnepans. But the FR drivers I had ended up sounding better in the smaller sized baffles. Ended up chopping down the countertops to <34" tall. Could of bought one 6'er to begin with and saved some cash.
https://www.homedepot.com/p/HARDWOO...ntertop-With-Eased-Edge-BBCT1502550/300688696
https://imagizer.imageshack.com/img922/8924/W1QSkS.jpg

Duratex can give you a nice, hard coating, if you can get the application down right (not streaky). Fairly forgiving. You can customize the color.
https://www.acrytech.com/product-category/speaker-cabinet-coatings/
I use this roller;
https://www.homedepot.com/p/FoamPRO...oth-Coater-Foam-Roller-Cover-156428/205037233
What I do is apply it heavy, then "unload" the roller of the extra paint, onto spare cardboard. I use cardboard moving boxes (also for HD). Then immediately go over the surface again very lightly. Try to do only upward facing surfaces at a time. Do 3 coats (1-1-1/2 hours between coats), 24 hours between sides, then let the entire project cure for a week.

The subs in the background, and bases of the OB are Duratexed.
 
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#62
adason said:
I have developped my own surface based on gorilla glue and paint. It may not be the prettiest, but I like it. Its acquired taste.
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Your solution and DuraTex seem to be similar idea?

How do people feel about Birch Plywood with a couple of coats of Polyx-Oil?

PolyX.png
 
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#63
I used water based poly (without stain) on my front and backs of baffles. Its about the easiest coating you can use. But it won't change the tone of the wood too much. For that you need to stain first. To match the butcher block unstained fronts of my baffle, I used maple band veenering on the sides, stained with Minwax Fruitwood stain, then poly coated.
https://www.homedepot.com/p/Varatha...-Based-Interior-Polyurethane-200231/100176203

BTW, our local Lowes sales Maple plywood, which can look better than birch. Only 3/4" thick though, maybe laminated it with birch in the back?.
https://www.lowes.com/pd/Top-Choice-3-4-in-HPVA-Maple-Plywood-Application-as-4-x-8/1000406045
 
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#64
Just testing the Zenith 49CZ852 without baffle on my desktop system, it sounds promising enough to go ahead with the OB baffle build.
When researching OB baffles, one tends to run into GR Research videos, which tout narrower front baffle with asymmetrical wings on the side more like flared U or V shape. Any merit in that approach vs. larger front baffle with hinged wings (i.e. Glow In The Dark Audio baffle)?

 
#66
I'm puzzled by the foam...what does it do!?
and also the asymmetry...why? Why didn't he ( it must be a 'he') put a trapezoidal baffle on the top, to let the paths being equal?
I mean, you make a barrier for not letting the sound coming from the back arrive ( sooner or later...)to you, and the upper part is left untouched.
In the first pic, a side is covered, the other not. I call it casual design.
 
#70
Poultrygeist said:
Using a heavy textured wall covering can offer a look similar to tooled leather plus it can help deaden the baffle.

I rarely use plywood as it's a lot more expensive than MDF which is a PITA to paint. I usually cover MDF with a wall covering and then paint it.

I see a lot of folks using really thick baffles that work well for high volume levels which can otherwise cause resonance.
I mostly listen to acoustic jazz at low to moderate levels which dosen't audibly excite the baffles and 3/4 MDF with some bracing if the drivers are really heavy works for me. The MDF edges I hide with molding.

View attachment 1412790
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I've stopped adjusting crossovers for tweeter placement, and for a fair time have returned to tweeters directly in vertical line with mids or woofers. Do you use a fairly steep filter in the crossovers for one or both drivers?
 
#72
I've been using these for awhile now, passive three ways as they are for a 2 channel music system, and also sharing them with an AVR for home theatre.
For home theatre ive been using a separate powered dual driver open baffle for augmenting bass below 60 hertz. I'd like to save some space and use a 10" sub driver on each baffle for distributed bass. The 12" from Sansui sealed speakers have new rubber surrounds installed by the vendor, and test about -3db at 32hz, plenty good for my choices in music.
Anyone use distributed bass, and have impressions of comparing it with a separate sub in its best location?
20250217_132442.jpg
 
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#73
here's some OB

Google Translate
https://translate.google.com/?sl=auto&tl=en&op=translate
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Maybelle Audio- Vietnam. Various speaker projects, some OB.

https://linhkienloadai-vn.translate...uto&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=wapp

https://linhkienloadai.vn/collections/mau-thung-1

Open Baffle two Eminence Alpha 15A & Visaton BG20, Simple crossover. PAP style

https://linhkienloadai-vn.translate...uto&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=wapp

from the video- crossover 9 min & sound demo 10:30 min

Screen Shot 2025-02-17 at 4.22.48 PM.png
Screen Shot 2025-02-17 at 4.05.38 PM.png



https://linhkienloadai.vn/products/loa-van-ho-lii-audio-leonidas
==============

Daves Fast Lane-
woofer magnet damping

https://web.archive.org/web/20140911011705/http://mysite.verizon.net/res12il11/id130.html

=========
https://zelfbouwaudio.nl/forum/viewtopic.php?f=59&t=14677

https://www.stereonet.com/forums/topic/65175-open-baffle-speaker-pics/

https://www.audiocircle.com/index.php?board=90.0

Stand
https://www.audiocircle.com/index.php?topic=154866.0
 
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#74
YTob said:
Your inquiry about OB could have been written by me about five years ago. Not any more, though. Now, my main speakers are proper speakers - should say, "boxes". And, I plan to purchase bigger "boxes" as an upgrade.
But what about OB? - Well, guess that in the past fifteen or so years I smartened up, got more informed and better educated. That's all. I do not wish to bore you, but can share briefly some basic findings:
1. Best drivers (in terms of sound quality) are compression drivers.
2. Compression drivers are generally loaded into horns, and no further enclosure is not necessary because they are monopole. You do not need any OB if you were doing horns.
3. OB is the type of "mounting" (cannot call it "enclosure") suited exclusively for dynamic "dipole" drivers. Those also radiate backwards, so proper positioning OB is tricky. Also, for OB to be really effective, it's size has to be specific to the dynamic driver you are using.

Now, as a wise luminary I consulted years ago about this said to me- OB can get you about 75% towards "decent" sound, but no further. This is just the way it is. Most OB enthusiasts either fine with it or simply have not heard better because most of what is available in the marketplace now is outright crap. In comparison to most crap, OB will sound "open" and "unconstraigned", but at the price of certain "density", tonality, color. OB cannot really pressurize a room the way a box can.

The revered Nelson Pass did some OB's and you can find his technical drawings for those on-line if you Google. He also spoke at length about what what I mentioned earlier- that you cannot get proper base out of OB without soing something special. In fact Nelson Pass came up with "velocity loading" - you can find his "white paper" on the subject if you search. It is a "slot-type" of loading that is somewhat similar to what is used in some sub-woofers. But the crossover then gets all funky and defeats the purpose of the "simple" wide-bander approach.

So, I call it the three phases of DIY enthusiasts:- you are currently at the phase #1- because almost everyone starts with OB.

Some get stuck in that, those that are - smarter (pardon me), handier, and more determined, then move on to the various boxes. That's the second phase in DIY.
The more ambitious try fancy transmission line boxes, which could be allright, and will get you about 85% there.

It is premature to speak of third phase here. Anyways, best of luck!

PS. Through the years and through experience, I got simpler- so, I'll finish by offering you two simple advices:
- 1. A well done SIMPLE box will go much further along than any hirsute OB. Here's a youtube video of a well-done simple box optimized for a specific driver with fairly complex crossover (yes, it is a Tannoy, sold for about $30k /pair). (These are not my vids, they just show nicely what good boxes can do for ya) Have a listen:
And may be this too:
(BTW- the second video shows Tannoy Kensington which are about $15k/pair, with GR drivers (Gold Reference) are currently trading for $4k if you can find a pair as Tannoy does not sell and never sold GR drivers and crossovers for them, so those come from old pairs that were taken apart...)
- 2. Even an open-backed box is better than an OB, if you decide you really must go audio "commando" or prefer "hirsute" lifestyle. Those do have "volume" calculations to be done, though open air is included, and those calcs are easy to perform.

Cheers!
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Good points. I started out with boxes, moved to OB, and finally added a open backed with a little cavity resonance to fill out bass to 60hz or so, and allow an also open backed with wings powered bass panel for bass solid to about 35hz. I have made dozens of what my customers consider high end box speakers, but these are for me and my own personal preferences. The sub is only for use with home theatre, whose receiver shares my stereo pair with my 2 channel system.
For my own use, using a computer display to get a flat response outdoors or in an anechoic chamber wasn't an option. Mine are made for my room and placement in it, and so far have easily outperformed any factory made for a generic environment speaker I've tried in here.
Aside from some D700, nothing I've owned, but merely borrowed for comparison, good examples I learned plenty from, Rogers LS 3/5A, B&W CDM 1, Totem Mani-2, and some Quad ESL 57, which confirmed I wanted open backed speakers at the least. Wish I had a pair around still for comparison. I think the midrange would blow mine out of the pond.
 
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#75
drjlo said:
Your solution and DuraTex seem to be similar idea?

How do people feel about Birch Plywood with a couple of coats of Polyx-Oil?

View attachment 1412935
Click to expand...
I make a wipe-on finish from gloss polyurethane with 20% mineral spirits. Wipe it on in the AM go to work come home sand it with fine sand paper and wipe on another coat. When you wake up it's done. You might add another coat to the top and then add a coat of paste wax if you want it to be protected from water and bourbon. You can pay extra for Osmo if you want, but I don't see what the big deal is. If you want a more natural look then use a tung oil finish, just give it time to dry (something no one has these days).
 
#76
drjlo said:
I think buying a low-cost router may be my better bet. I see the 2"x4" plywood from Home Depot/Lowe's, but man, their looks aren't going to make it in the house. How are people making these plywoods look better..? Cabinet shops sounds like $$
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If you're okay with plywood, Home Depot offers Columbia plywood. I think the outer layers are hardwood sandwiching poplar or similar. My current open baffles are made of the hickory choice of this. It's available in white or red oak, birch, mahogany, hickory, or maple where I live, although it's a delivery- no instore stock to view option. With my leftover blend of boiled linseed, walnut and tung oils my speakers and bass panel look as I'd hoped.
Typically it's offered in 4x8, and 2x4 foot sheets, although I've seen at random times cuts of 2 or 3 feet by 10 5/8ths available, which I've used for simple plinth.
Cutting driver through holes in them, they are NOT void free, but not riddled with them either.
Even when I gave my bass panel a good workout with both 10" subdrivers splitting near a thousand watts from 25hz to 80hz, the panel didn't rattle.
 
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