View unanswered posts | View active topics It is currently Thu Sep 21, 2017 1:32 pm



Reply to topic  [ 51 posts ]  Go to page 1, 2, 3, 4, 5, 6  Next
Cheapish HiFi Bookshelf Speakers Limited Tools NO Aesthetics 
Author Message
Moderator
User avatar

Joined: Tue Jan 15, 2008 2:31 pm
Posts: 14771
Location: Home sweet home!
Split off from the amp thread!

I ordered some drivers to make speakers to drive with this thing, today! Time to design a set of boxes, and pull my finger out re getting PCBs made!

Thanks to MrOnion for automating my life!

Image

_________________
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!


Thu Feb 14, 2013 12:23 am
Profile WWW
QFP80 - Contributor
User avatar

Joined: Tue Jul 06, 2010 1:03 pm
Posts: 45
Location: Espoo, Finland
Dude! Hahaha... You learn finnish on the way too. Did this to my friends uncle a while back (well looks like 13 yrs) who publishes hifi magazines. Funny how you find your early "work" is still online and even usable...

.. and reminds you how many fucking years you have been sitting on this damn machine. ;)


Thu Feb 14, 2013 12:35 am
Profile
Moderator
User avatar

Joined: Tue Jan 15, 2008 2:31 pm
Posts: 14771
Location: Home sweet home!
Did this to! LOL! What, like a punishment? ;-)

_________________
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!


Thu Feb 14, 2013 8:03 am
Profile WWW
Moderator
User avatar

Joined: Tue Jan 15, 2008 2:31 pm
Posts: 14771
Location: Home sweet home!
How much is that doooogy in the window, toot toot, I do hope that doooogy's for sale, toot toot.

Went to look at wood. MDF. 19mm 300mm 2440mm 8.27l internal volume.

If I were to be horribly and unforgivably stupid and ignorant I'd make it a cube. If I did that, the internal walls, assuming no stuffing, no bracing, no speaker back intrusion, etc, would be:

3√8.27 = 2.02225151688209 decimeters or 20.2225 centimeters or 202.225mm, which would be awfully difficult to achieve with 300mm wide MDF, even after subtracting 38mm + 4mm for thickness and sawcuts.

So given my lack of tools, it'll likely be 300mm ID one way, and 300 - 38 the other, minus 20mm square corner braces, gives us a cross section of:

(30 * 26.2) - (2x2x4) = 770 sq centimeters! DuckDuckGo fucking ROCKS! (mixed multiplication symbols and it still works!)

Converting that to square decimeters is 7.7 more math required:

<went to bed, got up again>

Volume of the bracing is ID of each dimension minus 4cm, times 2cm * 2cm x 2 of:

((30 + 26.2) - 8) * 2 * 2 * 2 = 385.6 ml

(0.3856 + 8.27) = 8.6556

8.6556 / 7.7 = 1.1241038961039

11.241cm / 112.41mm high which isn't big enough for the driver in question, so it'll have to be whatever the driver needs high, and tuned with sand filling.

More as it comes to hand.

Fred.

PS, I'd had a few wines before the <> interlude.

_________________
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!


Fri Feb 15, 2013 9:27 am
Profile WWW
Moderator
User avatar

Joined: Tue Jan 15, 2008 2:31 pm
Posts: 14771
Location: Home sweet home!
Speaker cut-out is 145.24mm max, plus 20 on each side for bracing (keep it simple for a simple boy) == ID of 185mm

Caps will need to be 300 + 19*2 long, and 300mm wide == 338mm

So, 8 * 185mm pieces @ 300mm wide + 4 * 338mm pieces @ 300mm wide == total of 2832mm + saw cuts, == two pieces to be diced up.

8 * 185 = 1480 + saw cuts
4 * 338 = 1352 + saw cuts

That's a bit awkward.

Fred.

_________________
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!


Sat Feb 16, 2013 12:00 am
Profile WWW
Moderator
User avatar

Joined: Tue Jan 15, 2008 2:31 pm
Posts: 14771
Location: Home sweet home!
Outer dimensions of the box as described above will be 300 x 338 x 225 which isn't quite golden ratio, but is good enough.

225 x 338 will be the front, which sucks, as that'll have the edges of both the top/bottom and sides exposed.

The sides will be smooth with screw holes. And to reduce volume I could inset the back by whatever I want, I guess.

I guess if they don't rape me for cutting fees I could take a few extra small pieces out for bracing internally. But maybe that's not worth it either.

Or maybe the offcuts could turn into a sub box. 4 @ 300 + 2 more @ 338 = a cubic foot and about right for a sealed bass driver.

6 * 338 = 2028

2440 - 2028 = 412 - 32 = 380 == more than 300 (1 out of 4)

2440 - 1480 = 960 - ((8 + 3) * ~5 cut) = fucking near exactly 3 pieces @ 300mm

I guess we'll see what the cutting fees are like! :-p

Fred.

_________________
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!


Sat Feb 16, 2013 12:40 am
Profile WWW
Moderator
User avatar

Joined: Tue Jan 15, 2008 2:31 pm
Posts: 14771
Location: Home sweet home!
Cuts are 50c each, and a little under 5mm wide, which is what I accounted for, IIRC.

Drivers arrived today! A little treat for Fred. So I went out and bought some stainless steel cap screws to match, and a bunch of various types of stuffing to fill the boxes with.

Need to pick up screws, Chinese jigsaw, glue, sliced MDF, and some square pine for bracing.

Also need to do work on the amp, or I'll never hear them...

Fred.

_________________
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!


Tue Feb 19, 2013 5:16 pm
Profile WWW
Moderator
User avatar

Joined: Tue Jan 15, 2008 2:31 pm
Posts: 14771
Location: Home sweet home!
It'll look something like this, I guess, but without the paint:

http://www.loudspeakerbuilding.com/Maga ... 00952,4353

_________________
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!


Wed Feb 20, 2013 11:35 pm
Profile WWW
Moderator
User avatar

Joined: Tue Jan 15, 2008 2:31 pm
Posts: 14771
Location: Home sweet home!
Final cutting list:

If taken from two sheets @ 2440:

  • 8 * 185 = 1480 + saw cuts
  • 6 * 338 = 1352 + saw cuts (2/6 for a sub)
  • 4 * 300 = 1200 + saw cuts (4/4 for a sub)

Divided in two, so as to guarantee sufficient material:

  • 4 * 185 = 740 + saw cuts
  • 3 * 338 = 676 + saw cuts
  • 2 * 300 = 600 + saw cuts

Per board @ 2440

If just what I really need:

  • 8 * 185 = 1480 + saw cuts
  • 4 * 338 = 1352 + saw cuts

Need to sort out a hole cutting option. So far a 35 euro ching chong router looks like the best (read cheapest) option. Might try to sort that out today.

Fred.

_________________
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!


Sat Mar 02, 2013 4:04 pm
Profile WWW
Moderator
User avatar

Joined: Tue Jan 15, 2008 2:31 pm
Posts: 14771
Location: Home sweet home!
Went on a mission to charge up car battery and get some bits for this:

  • 4.8 meters of 21mm square pine hand-selected for straightness, check.
  • PVA in a bottle with Poly Vinyl Acetate no where to be seen on it, check.
  • 500 No. 2 pozi-drive 4x40 zinc-plated self-tapping wood screws, check.
  • Medium length No. 2 pozi-drive driver bit for cordless drill, check.
  • Dirty, filthy, cheap, nasty, wretched and Chinese wood saw, check.
  • 1L of alcohol unrelated to this project, check. (can't get a litre of meths anywhere here...)
  • MDF sliced to perfection, FAIL. Another day, I guess.
  • A "fresadora" and appropriate router bit for making round holes cleanly, FAIL. Also another day, I guess.

Dinner time! :-p

Fred.

_________________
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!


Sat Mar 02, 2013 10:06 pm
Profile WWW
Display posts from previous:  Sort by  
Reply to topic   [ 51 posts ]  Go to page 1, 2, 3, 4, 5, 6  Next

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group
Designed by ST Software for PTF. ColorizeIt.