HD215 MOD to fit Martin Audio 115
Printed From: Speakerplans.com
Category: Plans
Forum Name: Other plans
Forum Description: Discussion / Questions about all the other plans
URL: https://forum.speakerplans.com/forum_posts.asp?TID=95318
Printed Date: 27 March 2026 at 4:05am
Software Version: Web Wiz Forums 12.08 - https://www.webwizforums.com
Topic: HD215 MOD to fit Martin Audio 115
Posted By: space141
Subject: HD215 MOD to fit Martin Audio 115
Date Posted: 25 March 2016 at 12:53pm
|
Hello to all fellow speaker enthusiasts! I have just acquired a pair of Martin Audio 115 cabs and would like to find a mid-bass cab to go on top that would work well with the flared design of the Martins (see below).  I really like the look of this 3 face HD215 and think it will look awesome on top of the Martin 115s.  I was thinking about bringing the top and upper 'lip' of the speaker out by 10.5cm to line up with the edge of the Martins so it all fits together nicely, something like this.  Does anyone have any suggestions as to whether it would be alright to simply go ahead with this or should I think about adjusting the curve slightly (moving it towards the mouth a little...) To be honest by the looks of it, it will just give the horn a little extra length which can't be a bad thing. Going to look ace with the martin 115s, HD215s and simplified mt121s - all flared!  Many thanks for your replies and interest, Thomas.
|
Replies:
Posted By: Twiggy
Date Posted: 25 March 2016 at 12:59pm
| The 115 and the HD both play the same freq band, just pick one or the other. |
Posted By: space141
Date Posted: 25 March 2016 at 1:03pm
|
Wouldn't it be possible to use the Martin 115s from 40-90Hz and crossover to the HD215s from 90-180Hz? Otherwise have you got a suggestion for a design which has a similar design that would be suitable for sub-bass duties with 18" drivers...? Thanks.
|
Posted By: fat_brstd
Date Posted: 25 March 2016 at 1:28pm
|
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. ------------- Melbournes Rootical Warrior Roots - Dub - Steppers http://www.facebook.com/adrians.wall" rel="nofollow - facebook page |
Posted By: smithshorn
Date Posted: 25 March 2016 at 1:42pm
| Don't know if there is much difference between the two cabinets, but do you have the Martin 115's, or the Fane long throw cabinets, as the plans you have posted are for the Fane. |
Posted By: Peter Jan
Date Posted: 25 March 2016 at 1:43pm
Those above are not Martin 115, but I think the illustration above came out of a Fane handbook and there was also a similar looking dual 12" low-mid/mid design to match. But anyway it's very similar to 115 and whatever you have there, they will most likely perform good both lower and higher than HD15. So why complicate things with extra crossover/amps/tuning and not just build an extra pair of what you have ? More of the same will make 'em drop a bit lower too. |
space141 wrote:Posted By: space141
Date Posted: 25 March 2016 at 1:55pm
|
Must be the Fane Long throw then but could only find that one image online as mine is much shorter at the back and has a bigger flare than the Martin 115 (as shown in the plan in the first post) just wasn't sure which model it was. I would like to avoid anything scoop-like as I much prefer the look of the concealed drivers with the flared design. Would it really be such a bad idea to have 2-way bass as I really like the look of the 215's and have a pair of PD154s lying around. Surely I still need kick bass bins above the Fane Long throws or can they deliver 40-180Hz whilst still giving a decent kick sound...? Also they will be loaded with RCF L15P200AK drivers (800W RMS, 1600 Peak). I do have another pair of RCF L15 554k drivers (600W RMS, 1200 Peak) - perhaps I'd be best building another pair of Martin Audio 115's as I can't find the plans for the Fane version apart from that very bad image at the top of this post. Thank you all for your advice, Thomas
|
Posted By: Peter Jan
Date Posted: 25 March 2016 at 2:17pm
How about a few pictures and measures ? Pictures of the insides, how speaker is mounted, etc... As I understand at this point, we don't know what we're talking about. Could be a horn design as well as a bandpass design. All are speakers in wooden cabinets, but respons could be totally different.
If they are what we assume, they will work very well even beyond 180 Hz.
I'm sure someone over here has still has that Fane book available, but let's first see what all ingredients are (the cabs on hand to begin with). |
Posted By: space141
Date Posted: 25 March 2016 at 2:37pm
Just checked measurements and they are definitely the Fane Long Throw design as shown below: With the same dimensions 1118mm wide at front, 660 at rear, 946 length & 468 height. Could anyone help me find a better resolution image of the original plans from the Fane Handbook that some people have mentioned? Would be great to make another pair to match! Cheers.
|
Posted By: DMorison
Date Posted: 25 March 2016 at 3:58pm
|
About 30 seconds with google finds this..... 
|
Posted By: DMorison
Date Posted: 25 March 2016 at 4:02pm
|
Also, if you want to model it (which you should do to check which modern drivers work well in it), check post 8 on this page.... http://forum.speakerplans.com/database-simulation_topic16974_page2.html" rel="nofollow - http://forum.speakerplans.com/database-simulation_topic16974_page2.html
|
Posted By: space141
Date Posted: 25 March 2016 at 4:44pm
| That's brilliant! What did you search for? Any idea what model this is... |
Posted By: jbl_man
Date Posted: 25 March 2016 at 4:45pm
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. |
Posted By: jbl_man
Date Posted: 25 March 2016 at 4:55pm
------------- Be seeing you. |
Posted By: DMorison
Date Posted: 25 March 2016 at 4:56pm
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.
|
Posted By: space141
Date 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.
|
Posted By: Peter Jan
Date Posted: 10 April 2016 at 12:49pm
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,... |
Posted By: Mark James
Date 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 :-) ------------- insert silly sentence here |
Posted By: csg
Date 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” |