Speakerplans.com Homepage
Forum Home Forum Home > Plans > Other plans
  New Posts New Posts RSS Feed - HD215 MOD to fit Martin Audio 115
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

HD215 MOD to fit Martin Audio 115

 Post Reply Post Reply Page  <12
Author
Message
jbl_man View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 12 January 2005
Location: London.
Status: Offline
Points: 11154
Post Options Post Options   Thanks (0) Thanks(0)   Quote jbl_man Quote  Post ReplyReply Direct Link To This Post Posted: 25 March 2016 at 4:45pm
Originally posted by fat_brstd fat_brstd wrote:

Martin 115's will cover from 40-180 no issues. Will actually play better than the HD-15 at 140hz+, HD is quite honkey if you play it too high.

If you want to go 2 way bass I would look at getting 4 scoops or large folded horns to run from 30-75 and use the martins above that but tbh I would just go for more of the same, its only gets better the more you add, 6 x 115's is great.


In the early days Martin 115's were used from 40 right up to 700hz...in fact one of their 'suggested' systems in the early brochure was a pair of 115's with the Martin radial horn just plonked on top,700hz crossover! Hifi it wasnt,but was simple,and it worked!
Be seeing you.
Back to Top
jbl_man View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 12 January 2005
Location: London.
Status: Offline
Points: 11154
Post Options Post Options   Thanks (0) Thanks(0)   Quote jbl_man Quote  Post ReplyReply Direct Link To This Post Posted: 25 March 2016 at 4:55pm
Be seeing you.
Back to Top
DMorison View Drop Down
Old Croc
Old Croc


Joined: 14 March 2007
Location: Aberdeen
Status: Offline
Points: 1647
Post Options Post Options   Thanks (0) Thanks(0)   Quote DMorison Quote  Post ReplyReply Direct Link To This Post Posted: 25 March 2016 at 4:56pm
Originally posted by space141 space141 wrote:

That's brilliant! What did you search for? Any idea what model this is...

Right clicked on your original image and selected "search google for image".... it really was that easy.

Only info I have is what's there, sorry.
Back to Top
space141 View Drop Down
Registered User
Registered User
Avatar

Joined: 18 June 2015
Status: Offline
Points: 30
Post Options Post Options   Thanks (0) Thanks(0)   Quote space141 Quote  Post ReplyReply Direct Link To This Post Posted: 25 March 2016 at 5:06pm
Here's a photo of them from the side just to confirm that these are not Martin Audio 115 as they do not have such a long box shape (or handles on the side) but are Fane Long Throw horns - not sure of model no yet.


Weird thing is though when I opened up the back I noticed that the driver was facing into the central enclosure which was lined with something like hessian fibre (coffee bean sack material) which was stuck to the driver surround which had disintegrated.



I also noticed that it had been modded with an extra wooden frame attached to the back with two walls to extend the neck and also did not have a wedge on the back plate - all very strange.



I have removed this add-on as I'd much prefer it to be nearer to the original (see bottom cab above) so plan on adding a wedge to the back plate and turning the speaker around so that it fires into the wedge which makes much more sense.

Any advice as to what material/ combination of material to line the inside of the chamber with. Also, what do people think about adding an extra bracing in the middle of the chamber to make sure it doesn't resonate too much...?

Sorry for all the questions, thanks for all the replies so far.

Thomas.


Edited by space141 - 25 March 2016 at 5:09pm
Back to Top
Peter Jan View Drop Down
Young Croc
Young Croc
Avatar

Joined: 16 December 2008
Location: Belgium
Status: Offline
Points: 1019
Post Options Post Options   Thanks (0) Thanks(0)   Quote Peter Jan Quote  Post ReplyReply Direct Link To This Post Posted: 10 April 2016 at 12:49pm
Originally posted by space141 space141 wrote:

Weird thing is though when I opened up the back I noticed that the driver was facing into the central enclosure which was lined with something like hessian fibre (coffee bean sack material) which was stuck to the driver surround which had disintegrated.

I also noticed that it had been modded with an extra wooden frame attached to the back with two walls to extend the neck and also did not have a wedge on the back plate - all very strange.

I have removed this add-on as I'd much prefer it to be nearer to the original (see bottom cab above) so plan on adding a wedge to the back plate and turning the speaker around so that it fires into the wedge which makes much more sense.

Any advice as to what material/ combination of material to line the inside of the chamber with. Also, what do people think about adding an extra bracing in the middle of the chamber to make sure it doesn't resonate too much...?

The wadding/damping is not really needed if you're not going to use it above 150-200Hz.  Above it helps to smoothen respons and that is also speaker dependant. So it might be not needed, depending on how you're going to use it, but it won't hurt either, even if not needed.

To get the best out of this design, you best refabricate the wedge in the back. Again, for only low frequency reproduction, it will work fine with the speaker reversed and no wedge, because the space the magnet/basket occupies, acts as a compressor just as the wedge would. The wavelengths of the lower frequencies are too long to have an adverse effect and the working is based on air compressing and expanding. The shape of the parts that make the compression happen, is not important. Once in the hundreds that becomes an issue, because of shorter wavelengths that need properly angled wave guidance not to refract back to the source and/or randomly reflect to everywhere and have destructive cancelations even before being directed back and forth in the hornpath.

Some extra bracing won't hurt. The main thing is to not have panels too large without support. Whether that is made up of small added ribs and/or interconnections with a panel on the other side of the cavity/hornpath, it all helps. Also make sure every panel of the cab is nailed, glued, screwed,.. firmly together and without airleaks, because that can be a source for chuffing, rattlling,...


Edited by Peter Jan - 10 April 2016 at 12:52pm
Back to Top
Mark James View Drop Down
Old Croc
Old Croc
Avatar

Joined: 15 January 2006
Location: rig side
Status: Offline
Points: 5309
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mark James Quote  Post ReplyReply Direct Link To This Post Posted: 13 April 2016 at 2:45am
if thats what you have allready got then more of the same loaded with the same drivers and amps and running the same signal etc is what i would suggest then when you have 6/8 of them if you decide you need more low low end get a few x1s or some other sub specific design and raise the lower crossover point from 40 up to 70 or wherether works out a good place to cross between the two cabs, more of the same cabs with same amping and drivers is what id suggest to start with tho 6/8 is where it realy starts to get fun :-)Wink
me so horny me love you long throw
horn loaded for her pleasure
Back to Top
csg View Drop Down
Old Croc
Old Croc


Joined: 17 September 2007
Location: bedford
Status: Offline
Points: 6086
Post Options Post Options   Thanks (0) Thanks(0)   Quote csg Quote  Post ReplyReply Direct Link To This Post Posted: 13 April 2016 at 8:45am
as above, these old 115's really need to be in blocks of 4 minimum to work well - but when they do, they really do...so stick with the design and just build more - mixing with hd215's would be totally counter productive.
“The fact is this is about identifying what we do best and finding more ways of doing less of it better”
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 0.139 seconds.