In this case that should be enough. I'd probably put a spine on the back wall if the driver is in the way for a front-to-back brace. I assume the crossbrace you're talking about is side-to-side?
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1x8 DIY practice cab build
- Thread starter JdoubleH
- Start date
In this case that should be enough. I'd probably put a spine on the back wall if the driver is in the way for a front-to-back brace. I assume the crossbrace you're talking about is side-to-side?
Yes, that's how I was thinking. Haven't drawn up my diagrams yet so it was mostly thinking through the keyboard. When I get down to business I will post up some plans for public flamage.
As I stated earlier, this really doesn't need much in the way of bracing. The excessive bracing I used was more or less a proof of concept for another cab (much larger). The funny thing is, I actually get a little vibration on the top (which by nature of this design is very stiff). The shuttle head is so light that depending on where it is sitting, I occasionally get a little buzz between the feet and the cab. It occurs to me that I might not get that if the other panels weren't so stiff.
dhomer
Commercial User
- Apr 9, 2009
- 675
- 13
- Disclosures
- Owner, Gigmaster Soundworks, Auth. greenboy designs builder, MI
I've been running through some possibilities in "upgrading" my Crate BX-25. Kinda settled on a Basslite CH2010, but there's another driver I'll probably model.. Its in the PE sales flyer - Dayton PS220-8.. Its a full-range driver, neo magnet, good xmax.. My goal is a solid B-string, so later on I'll run the numbers and report back..
dhomer
Commercial User
- Apr 9, 2009
- 675
- 13
- Disclosures
- Owner, Gigmaster Soundworks, Auth. greenboy designs builder, MI
The amp is like 25W max at 4ohms.. Running the numbers on it, it ain't too bad.. In a 3740cu.in box tuned to 49, I can pretty much match the SPL graph w/the CH2010 (same wattage, the Eminence needs like a 2.2 cu.ft. box). I'd have to match the Emi to some sort of mid driver, which at this point I hadn't settled on. The Dayton is a full-range driver, but its got a low-mid dip not unlike a BP102. If overall performance was the deciding factor, I'd probably still go w/the CH2010..
Great design and superb execution, JdoubleH! I'm inspired to put together a battery powered version, and I've started getting parts.
Like ian_s, I'm getting Vb = 69 liters with WinISD. I get similar results with several on-line calculators, including those at madisound.com and diyaudioandvideo.com. Lowering Vb to 28 liters (1 ft^3) gives Qtc of 0.93 with what looks to be a 1 db peak at about 100 Hz. Will that cause problems?
The relevant values I'm using for the speaker are: Fs: 28.8 Hz, Vas: 98.26 liters, Qts: 0.4529. Are these different than you are using for the 55-2971 driver?
Like ian_s, I'm getting Vb = 69 liters with WinISD. I get similar results with several on-line calculators, including those at madisound.com and diyaudioandvideo.com. Lowering Vb to 28 liters (1 ft^3) gives Qtc of 0.93 with what looks to be a 1 db peak at about 100 Hz. Will that cause problems?
The relevant values I'm using for the speaker are: Fs: 28.8 Hz, Vas: 98.26 liters, Qts: 0.4529. Are these different than you are using for the 55-2971 driver?
Didn't get a chance to cut up wood, but did spend some time scribbling on paper and web searching. I found a spreadsheet at The Subwoofer DIY Page v1.1 - Sealed Systems which feels nicer than WinISD (especially in this case where the drivers aren't in the database anyway). The .zip file from that site includes documentation on use.
I posted a version of the sheet here which uses the MCM driver, and the box size as (15x13x11" in liters). I would have put it into Google Docs but then the graphs disappear.
Now we can all play with the numbers, if we like.
I posted a version of the sheet here which uses the MCM driver, and the box size as (15x13x11" in liters). I would have put it into Google Docs but then the graphs disappear.
Now we can all play with the numbers, if we like.
Very cool.
For those of us who are interested in learning a bit about how all this works (but currently have no clue) this looks like a gateway document to gaining some small understanding. It's way over my head now, but is a fascinating glimpse into another world.
For those of us who are interested in learning a bit about how all this works (but currently have no clue) this looks like a gateway document to gaining some small understanding. It's way over my head now, but is a fascinating glimpse into another world.
Old post I know but it inspired me to build one. Still needs to be finished, but sound test went great. Speaker was from Parts Express.
Too cool! I totally forgot about this thread. I still use the cab. It's my default practice cab in my music room. I generally power it with an 800w/ch 8 ohm power amp driven by an Eden WTDI (not pushed anywhere near 800w obviously). The only issue I have is the grill rattles sometimes. Other than that, it still sounds fantastic at bedroom levels.
Glad you saw this post. Many thanks for the inspiration and the detailed pictures. Could not have done it without that. I tested with an Eden TN, which is 225 watts I think. I refined your idea on the cable gland, size PG11. I drilled a 1" hole partly through, with a 3/4" hole in the middle, which created a lip that allowed the gland to work without modification. I mounted the handle diagonally to leave more space for the cable. It's very light, so happy.
Great work and nicely detailed description. It's cool guys like you are here on TB.
