What have you found today?
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Just looking at the Buyouts section to see what’s there, and I clicked on this CES 8″ DVC woofer. Enough info included to get a rough idea of what “could” be. Probably optimistic, just looking at the size of the magnet, but at $11.88, could be fun to experiment with.
What have you found today?
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Those actually look VERY interesting for $11.88
I was actually looking at these this morning: https://www.parts-express.com/Thruster-THW835-8-Subwoofer-299-222?quantity=1
but they’re nearly double the price, and have a terribly ugly dustcap as well lol! Any ideas on what you would do the those CES drivers?
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That is a good find. That could make a really fun multi sub build as well. Like 12 or 20 running together.
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Ah yes, the “venerable” Thruster branded drivers. Inexpensive and they work for a while, or so I’m told. 😁
The CES unit, well..
It’s a DVC unit with a small ceramic magnet, so it’s got me questioning just how good it could be. It says it’s a woofer, not a subwoofer, so it has that going for it.
Running quick calcs for the optimum box gives me 5 cu.ft., 3″ port @ 3-1/3″L, box and port tuned to 26Hz and an F3 of 19.5Hz. That seems way too big and soft for an 8″. I suppose I’d start with a test box of 12″wx12″h that I could slide a back along to see how different volumes worked with it. Make it, say, 24″ deep, to create a 2 cu.ft. box, and have the port stick outside the back (moveable panel) that you could trim to the calculated lengths. Make up 4 ports and try it at 1, 1.25, 1.5, and 2 cu.ft. to see the differences.For example, the calculated extremes are:
1CF = Fb & F3 @ 44 Hz, 3″ Port @ 7-5/8″, and a Peak of 5dB above baseline, which tends to come before the box tuning.
2CF = Fb =35 Hz, F3 = 31 Hz, 3″ port @ 5-1/2″, and a Peak of 2.9 dB above baseline.I have no clue what it’s SQ is.
You could go with them as 4 ohm woofers in a set, or, since it’s a DVC, you could use it in a small console style unit with smaller drivers to the outer sides and the CES in the middle, with one VC hooked to the left channel and the other hooked to the right channel. Mate it with some full range drivers, like a 2-1/2″ to 4″ Dayton Audio (PC-83?) , with a relatively low crossover (150Hz?) and it’d be schweet! And instead of one 3″ port, you could do two 2″ ports the same length as the 3″ and have symmetry.-
I was just thinking to make a couple of ridiculous arrays of like, 8 them lol
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At that amount, it’d be under “a buck fiddy” and you could wire it in all kinds of ways, depending on the amp. Could be fun to experiment with.
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I think I may have found a way to get worthwhile surround sound in my particular viewing space (old Victorian 1/2 a double with way too many doorways, an archway, 1/2 open stairs and big old cast iron hot water room heaters). Picture this: all the speakers could be 2″ – 3″ single drivers, with either a small sub under and maybe a butt kicker, run on some of those 15 W class D amps from a previous thread. You could go nuts on the number of channels, with the hardest being the center (how to mount it). It’s got me thinking…
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Get 32 of them, and a Trinnov lol
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Extra 20% off…..
16x for only $152.06
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In my typical “he’s MAYBE overdoing it” fashion, I grabbed 32x.
I’ll eventually think of something to do with them 🤣
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Allllll-righty Then! Lessee what you come up with.
(BTW, 32 – 2″ drivers have the same basic cone area as an 11-1/4″ driver, 32 – 2-1/2″ drivers have the same basic cone area as a 14″ driver, while 32 – 3″ drivers have the same basic cone area as a 17″ driver. Just random calculations, no real reason to throw that out there. 😁 )
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I’m thinking just 4 simple towers using 8 drivers each
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I ran the maths… 32x 8″ woofers have the equivalent surface area of 4.64x 21″ woofers
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Or 8 bookies with 4 drivers each?
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That would make for some good dispersion, but would be a PITA for placement and cable management
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The big question is: What drivers did you order?
My curiosity is piqued. -
The CES 8″ drivers
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Ah, the OG drivers of this thread. 4 -8’s. It’ll be interesting to see how you design them.
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Referring to whatever I will throw together as “design” is very generous of you lol
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🤣🤣🤣
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Currently thinking that building based on this form factor would be most simplistic.
Sealed cone-to-magnet iso groups, 4 high with no dividers between them. So, the ones on the front baffle all sharing one airspace, and the ones on the “internal baffle” sharing one airspace. Should end up with a reasonably sized enclosure. Also this design overcomes the “eyesore” typically associated with isobaric designs: having the magnet. visible on the outside of the enclosure. Instead, the cones would be visible, appearing to be just a standard speaker/subwoofer tower.
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if you go this route id consider rather than having the front baffle as a 4×1 column of woofers to do a 2×2 grid instead
see the 4x 5″ low mid driver layout on this genelc studio monitor as an example of why, product page and YT video with R&D discussion linked
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i guess what im really im saying design it like this very, very rough model 😆
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Would this be beneficial, if the intent is to simply use them and cheap near-field subs?
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that depends on the geometry of the room they are going in and the overall height of the cabinet
4×1 should be phase aligned horizontally very well but may do weird stuff in vertical
2×2 will act as a kind of single point source coaxial cabinet so will be phase aligned reasonably well but aligned in all directions
the shape of the acoustic space and their layout relative to each other will determine if this co planar effect is beneficial in this scenario
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Got my boxes of drivers in…
Guessing I should order DATS and BassBox Pro if I want to actually try and make something nice/cool/epic, right?
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Depends on how big you want to go. A 10 CuFt ported box will theoretically get you a 33/28 fb/f3 with about a 2-1/4 dB rise near fb, for 16 drivers in the combo isobaric/compound configuration, probably at 8 ohms.
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I’m not scared of large enclosures, that’s for sure… 10ft³ is definitely massive though 🤣
But, I’m intrigued
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Here’s a couple of scenarios for a 10 ft³ box with 8 pairs in an Iso/Comp configuration:
Just the 10 ft³ box w/ ¾” walls outside dimensions
Golden ratio 43 ⅓” x 27 ⅓” x 17 ½”
Acoustic ratio 34″ x 27 ⅓” x 22″
Of course you’ll have to take into account anything that takes up room and expand accordingly.The 3 ports Listed below are just based on easily acquired PVC or thick wall plastic pipe:
6″ x 2 ¾” L
8″ x 6 ⅞” L
10″ x 12 ½” L
Of course a slot port can be used, just remember 𝜋R² and work it back from there.
No, I haven’t done any modeling in WinISD, these are just quick calcs to see what can be done.
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Another quickie, all from the special buys section, except for the cap.
The CW125204 4-1/2″ Paper Cone Woofer @ $4.98 each ($9.96) Part #299-4246
JSD VDT-4015 1/2″ Mylar Dome Tweeter Pair 8 Ohms @ $5.88 Part #299-4314
Round Speaker Wire Terminal Cup Spring Type @ $1.38 each ($2.76) Part #260-294
4.7uF 100V Electrolytic Non-Polarized Crossover Capacitor @ $0.79 each ($1.58) Part #027-332
Throw it all in a 0.5 cuft box with a 1″ port @ 1/2″ long, designs out to a 58 Hz tune and F3 of 45 Hz up to 20 kHz, crossover just above 5K, and around 88 dB.
That’s a small bookshelf pair for $20.18 plus shipping. ~ $30 total, minus wood, screws and wire
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