Speakerplans.com Homepage
Forum Home Forum Home > Plans > HD 15 horn
  New Posts New Posts RSS Feed - HD15 Simplification
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

HD15 Simplification

 Post Reply Post Reply Page  <12
Author
Message
davey t View Drop Down
Young Croc
Young Croc
Avatar

Joined: 11 March 2004
Location: Bristol UK
Status: Offline
Points: 1428
Post Options Post Options   Thanks (0) Thanks(0)   Quote davey t Quote  Post ReplyReply Direct Link To This Post Posted: 16 September 2004 at 10:39am

the curved section can be done in 20 minutes. Just create curved guide rails down the sides to screw too. Then glue one side of all 5/6 pieces. Screw them all into the bottom, and start bending by screwing into the guide rail ever 2cm. Worked great, we have a perfect curve with no problems. Took 2 days to build 4!

Have e-mailed the construction pic to Rog but he has yet to put them up...

Back to Top
davey t View Drop Down
Young Croc
Young Croc
Avatar

Joined: 11 March 2004
Location: Bristol UK
Status: Offline
Points: 1428
Post Options Post Options   Thanks (0) Thanks(0)   Quote davey t Quote  Post ReplyReply Direct Link To This Post Posted: 16 September 2004 at 10:40am
Oh, and you need 2 people to do it this way, one to screw, and the other to literaly stand on the layers to bend them!
Back to Top
loophole View Drop Down
Registered User
Registered User


Joined: 02 March 2004
Status: Offline
Points: 469
Post Options Post Options   Thanks (0) Thanks(0)   Quote loophole Quote  Post ReplyReply Direct Link To This Post Posted: 16 September 2004 at 12:16pm
what do you think of the structural strength of doing it that way davey? its tempting, but i'd be worried about glue in the inner layers setting correctly
certain patches inside might never get the cure they need to get the glue's full strength

curved formers is the only way to go, they dont take long to make either. personally, i glued each layer, one a day. a bit of steam from a kettle can make the bending a lot easier, as can making sure the grain of the ply runs the right way (much much easier to bend when the grain runs across the curve than around it)
Back to Top
Andrew View Drop Down
Registered User
Registered User


Joined: 10 March 2004
Location: United Kingdom
Status: Offline
Points: 669
Post Options Post Options   Thanks (0) Thanks(0)   Quote Andrew Quote  Post ReplyReply Direct Link To This Post Posted: 16 September 2004 at 12:57pm
Using load straps means you can build the cabinet single handed.  Can get quite a force to hold down the layers this way.
Back to Top
matt andrews View Drop Down
Registered User
Registered User


Joined: 15 September 2004
Status: Offline
Points: 501
Post Options Post Options   Thanks (0) Thanks(0)   Quote matt andrews Quote  Post ReplyReply Direct Link To This Post Posted: 16 September 2004 at 5:26pm
Sorry to drag this one out, but i think im gonna go with the standard access panel design. If I am doing this might as well do it right first time.

Anyway, how big does the access hole need to be (i wont buy a drive untill i have completed the box), would strips of 18mm ply be ok for the recessed bit (not sure what word to use here).
Back to Top
Andrew View Drop Down
Registered User
Registered User


Joined: 10 March 2004
Location: United Kingdom
Status: Offline
Points: 669
Post Options Post Options   Thanks (0) Thanks(0)   Quote Andrew Quote  Post ReplyReply Direct Link To This Post Posted: 16 September 2004 at 5:58pm

Specs for most drivers are on the www.  Rog likes access panels as small as possible to improve rigidity.

The access hole for the driver ends up on the top of the unit, which makes it look a bit messy (with my carpentry anyway).  However I've not built it dom's way, with leaving the bass (top in the diagram) off until the end of the build.

My back panels are stiffened a little with an additional layer of ply glued down on part of the back to help support the speakon connectors.

Good luck with the build.

Back to Top
spaceman View Drop Down
Registered User
Registered User


Joined: 26 July 2004
Location: United Kingdom
Status: Offline
Points: 52
Post Options Post Options   Thanks (0) Thanks(0)   Quote spaceman Quote  Post ReplyReply Direct Link To This Post Posted: 16 September 2004 at 9:35pm
wot size shoud i get my thin ply cut? too idle to work it out. plus is flexi-ply any cop? enquired at the timber yard its not cheap, fust for a small pannel. 30 squids for 8*4.
Back to Top
Dave Slater View Drop Down
Registered User
Registered User


Joined: 28 February 2004
Location: United Kingdom
Status: Offline
Points: 373
Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave Slater Quote  Post ReplyReply Direct Link To This Post Posted: 16 September 2004 at 10:54pm

doing the curve is easy

when Dom and i did ours we had the individual sheets over sized so that they all but touched the back of the cabinet

make sure they're cut so that the grain goes across and there will be enough give in them

glue and screw the first to a batton running across the front of the cab then bend it over and glue and screw to the top of the baffle

you can then panel pin the next two sheets down with loads of pva inbetween especially from across the baffle and with plenty on the bit that over hangs to make sure of a good joint

if you look at this picture you'll see a length of wood being held by a G clamp this was pushing down on to the sheets ensuring enough pressure was there during the drying so that it's sealed well

to be honest that is the most important part that you have to make sure is completely glued up or it will vibrate

the final sheet is screwed through into the batton and baffle again the wood is placed there for pressure whilst drying

once it's all dry all you have to do is measure 120mm from the back and saw it off in a straight line

Back to Top
davey t View Drop Down
Young Croc
Young Croc
Avatar

Joined: 11 March 2004
Location: Bristol UK
Status: Offline
Points: 1428
Post Options Post Options   Thanks (0) Thanks(0)   Quote davey t Quote  Post ReplyReply Direct Link To This Post Posted: 17 September 2004 at 9:34am

Originally posted by loophole loophole wrote:

what do you think of the structural strength of doing it that way davey? its tempting, but i'd be worried about glue in the inner layers setting correctly
certain patches inside might never get the cure they need to get the glue's full strength

Its as solid as rock. Used lots of glue and screws and it set as if it was a 18mm thick piece of ply. I really reccomend doing it this way, it made them so easy to build.

Back to Top
Andrew View Drop Down
Registered User
Registered User


Joined: 10 March 2004
Location: United Kingdom
Status: Offline
Points: 669
Post Options Post Options   Thanks (0) Thanks(0)   Quote Andrew Quote  Post ReplyReply Direct Link To This Post Posted: 17 September 2004 at 9:46am
My HD15 curved horn is built from three 3.6mm ply layers and an even thinner finishing layer, almost a laminate.  I use no screws for the horn, just glue, two layers of ply and it is reasonably solid, three layers and it is rock solid, finishing layer and it also looks pretty.
Back to Top
nightline View Drop Down
Registered User
Registered User


Joined: 28 February 2004
Location: Netherlands
Status: Offline
Points: 70
Post Options Post Options   Thanks (0) Thanks(0)   Quote nightline Quote  Post ReplyReply Direct Link To This Post Posted: 18 September 2004 at 11:27am

Originally posted by matieo matieo wrote:

Firstly, thanks for an excellent resource!

I would like to make a HD15. Unfortunatly I am inexperienced in carpentry so am trying to simplify the plan as much as possible.

Would either of these modifications be sensible, how much would they damage the performance of the speaker?

- Replace the curved section with 3 pieces cut with angled (mitred?) edges to simulate a curve

- Have the back or base removable for driver access

Of course, if all go's well; I will want to make more than one
Matt

 

I.ve build a few double HD15 with the curved section replaced by 2 peices, and one of them is removeble for speaker access.          ;     The original HD15's i've build are powered by Beyma 15G400 speakers.  The double versions are powered by 18Sound 15W1402, and the a few with neodymium drivers from 18Sound.

 

Kind regards

 

Jack

Back to Top
 Post Reply Post Reply Page  <12

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.06
Copyright ©2001-2023 Web Wiz Ltd.

This page was generated in 0.125 seconds.