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18" reflex sub ports

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stalian87 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote stalian87 Quote  Post ReplyReply Direct Link To This Post Posted: 25 August 2017 at 2:38pm
flip sake, i wrote a huge paragraph and then refreshed the page and lost it!

anyway, i'm not too bothered about weight as my th18s are 100kgs each but size is a little more of a priority although it looks like i'll be compromising on that as well!

I'll defo still to the 1 box 4 drivers idea as i really like the look and i'm sure it'll kick some butt!
I'm gonna forget the ports for now.
unfortunately front mounting might not fit so i'm gonna have to stick with rear mounting and stuff some fibre to compensate on the smaller volume.

just added some drivers for graphical purposes.


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Hemisphere View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Hemisphere Quote  Post ReplyReply Direct Link To This Post Posted: 25 August 2017 at 3:17pm
Are you certain reverse mounting won't fit? The Faital Pro 12FH500s we looked at have a very suitable magnet/chassis structure for that sort of thing - They look even better from the rear than from the front, and the neo magnets are quite long and narrow.

It's worth rendering the woofers with some degree of accuracy (approximate dimensional accuracy at least) and actually seeing for sure. My instinct says they will fit fine. 

Tom Danley always renders his components in intricate detail, as you can see from his promotional materials. That's one of the main tricks to fitting lots of drivers in a small space.

The other midtop that was recommended in this thread (I forget the name.. by Peter somebody, with the dual 12" horn loaded low end), even makes sure the bass drivers are rotated to exactly the right angle that the compression driver fits in the gaps between the chassis supports, to within a cm or two of clearance.

Edit: If you're confident enough in the quality of your CNC guy's work to make the shapes you've rendered so far, I think there is a possibility to move the baffle even further forwards, by cutting the space in front of the cutouts like you did the space behind, and squaring off the end, perhaps recessed by a couple of cm from the front so each flat corner works as a mounting point for the grille.


Edited by Hemisphere - 25 August 2017 at 3:25pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote smitske96 Quote  Post ReplyReply Direct Link To This Post Posted: 25 August 2017 at 3:21pm
I own two TH-18's as wel, and i'm also thinking to expand the system with a kick section.
But the kick, must also be used as a simple stand-alone sub from 45/50 Hz up.

The idea of Hemisphere was exactly what I had in mind. My idea was first one (later two)15" kick/sub, probably light cone driver. And a BMS coax on top.

For now I have two front loaded 12/1.4 mid highs, so combining those with a small 15" would be really flexible.

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stalian87 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote stalian87 Quote  Post ReplyReply Direct Link To This Post Posted: 25 August 2017 at 4:23pm
yeah i'll have a look again at front mounting and cutting the baffles from the font so i can extend the box rearwards to gain more internal volume.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote odc04r Quote  Post ReplyReply Direct Link To This Post Posted: 25 August 2017 at 4:46pm
It's an interesting box design, but will be a nightmare to build and brace well. Pretty short horn path too. None the less, why not go for it. Got to keep life interesting.


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Post Options Post Options   Thanks (0) Thanks(0)   Quote Hemisphere Quote  Post ReplyReply Direct Link To This Post Posted: 25 August 2017 at 5:04pm
It's only playing up to 125Hz so any benefits from the 'horn' (on SPL/frequency response at least) won't be significant. Ideally it would be even shorter than it is. Could be cut down to 35cm or so?

Looking at it, I can't immediately see a way that those angled baffles could be cut without cutting angles on both sides of the wood. If you've only got to cut angles on one side then you should be able to get the cuts precise enough  to assemble.. but those angled baffles have a lot of joining edges. 

They've got to sit flat against the enclosure walls, flat against each other, and ideally flat against one of the four braces that should run along the the seams where the angled baffles join.

For those braces you could possibly take something like 2 sheets of 10 or 12mm ply, stuck up against each other, each cut with an angle on the inwards facing edge which matches the angle that the angled baffles will be sitting. That might do it. I think then all the angled cuts on the baffle sections would be on the underside.


Edited by Hemisphere - 25 August 2017 at 5:07pm
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stalian87 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote stalian87 Quote  Post ReplyReply Direct Link To This Post Posted: 25 August 2017 at 5:19pm
Yep, lots of weird and wonderful angles but should be straight forward for my cnc guy. Once I get a 2D plan for each piece, ill then see if these baffles are even cuttable but I'm pretty sure they'll be fine.

He's cut some messed up angled pieces for me in the past with no issues so hopefully same story here. It's gonna costa pretty penny though as every side on each baffle has a different angle.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Hemisphere Quote  Post ReplyReply Direct Link To This Post Posted: 25 August 2017 at 5:57pm
Would it be inappropriate to suggest splitting it into two boxes again at this stage? :D
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stalian87 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote stalian87 Quote  Post ReplyReply Direct Link To This Post Posted: 25 August 2017 at 6:17pm
Haha yes very much so! I love the look so much I'm gonna make this work if it's the last thing I do ;) I love a challenge.

By the way, can someone please explain exactly what a. Synergy horn is? I'd love to build one to finish my stack at some point.

In the Danley sm80, is there more drivers than the 12" coax in that box?

Edited by stalian87 - 25 August 2017 at 6:41pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Crashpc Quote  Post ReplyReply Direct Link To This Post Posted: 29 October 2017 at 12:54pm
Bhaha, I can see where you´re going.
Looks nice indeed. I´m thinking about downsizing (not by absolute size, but size per piece), and I have no idea how to do it right. One day, I´ll find it....

Synergy horn is a horn. :-D
The magic around it is, that it is made to produce the whole band (often with support of subwoofers, but can do without). I.E. All speakers work in a single horn, compared to conventional designs, where each band had to have its own horn. Now it´s all in one, so to speak...
Of course, once you need all speakers to play in a single horn, things get very complex and difficult to make.
Nikon and Canon people should not be married to each other. Why did you let this happen?
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