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Elite Shackster
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Discussion Starter · #1 ·
Ive started building my own DIY sub (last night) and thought I'd share it with everyone. Background info is as follows. I'm using a Behringer EP4000 for power, 2 15" Acoustic Elegance Drivers, and the cabinet is constructed from 1" MDF and yields about 180 litres. There isnt a lot more than that to say about it really, but if anyone has any questions then I'll be happy to answer. Heres the pictures showing my progress since I started last night:

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8.jpg

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15.jpg

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Dan,

Its good to see your sub build. It didn't take you long at all did it. Looks great mate.

Looking forward to see what results you get with it. How much does it weigh by the way.

When do you think you will get it up and running. I will be doing my fan mod on my behringer today as I just can't stand it anymore. When you doing yours?

cheers

Graham
 

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Elite Shackster
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7,142 Posts
Discussion Starter · #3 ·
It weighs more than the Ultra did anyway, not sure on the exact figure, but I reckon I could lift it ok with some help from a second person. I'm not planning on modding the amp just yet, the place I'm going to put my amp is out the way so its shouldnt be too big an issue for me hopefully. I'll run some preliminary tests tonight, but I'm still considering adding a second brace so the cabinet will be a little leaky as the lid wont be sealed yet. I want to run the drivers in more than anything but I'll do some low level listening tonight, and probably get to running some graphs in the next couple days.

Anyone got any thoughts on adding a second brace. Right now I'm thinking the lower angled baffle is essentially acting as a brace so a second one is necessary. Also both drivers are supported by the baffle, and a secondary VC support (the lower driver sits on the floor perfectly) so that should take some strain from the cabinet. To add to that the design is almost dual opposed so that should further aid cabinet vibration reduction. Feel free to criticise.
 

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Elite Shackster
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7,142 Posts
Discussion Starter · #5 ·
Looks good! I like the magnet support in the brace. I agree you should add a second brace.
Cheers Mike,

I was quite pleased with that support, it lined up perfectly first time and fit really snugly. I've been trying to think how best to go about adding the second brace and I'm not sure which way to go, but its going to end up above the lower driver somewhere. I'm really eager to get the thing running though, so thats pulling me away from putting another in, I'll have to try ignore the devil on that shoulder.

Hopefully though, I'll be running tonight. I'll get the pics up later.
 

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Elite Shackster
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7,142 Posts
Discussion Starter · #7 ·
Nice work on the sketchup Graham, cheers. Thats not a bad idea either, although I'm thinking of just putting in a second brace same as the first over the lower driver now. It'll be easier to construct and fix and will probably be a little stronger. I'll upload pics when their ready with whatever I decide to go with.
 

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Looks like an interesting project... looking forward to the finish and some measurements.

I also agree that another brace would be good.

Is the other brace snug around the driver magnet? I am thinking that needs to be a very tight fit to keep it from vibrating against the wood. Maybe even a little silicone to seal it tight if there is any small gaps anywhere.
 

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Elite Shackster
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7,142 Posts
Discussion Starter · #9 ·
Looks like an interesting project... looking forward to the finish and some measurements.

I also agree that another brace would be good.

Is the other brace snug around the driver magnet? I am thinking that needs to be a very tight fit to keep it from vibrating against the wood. Maybe even a little silicone to seal it tight if there is any small gaps anywhere.
The fit around the magnet is excellent. I cut it exact size and then sanded it to give a press fit. It actually held the driver in place without any fixings :T.

I had a long hard think about a second brace, but the lower baffle comes half way up the cabinet and acts like a brace anyway, so decided to leave it be. Eagerness to complete may have had something to do with that as well though :bigsmile: . Ive give it a bit of juice and there is no noise I can pick up on coming from the cabinet, so I think Ive got away with that one even though part of me wishes I had put it in.

The sub is running now and I'm very please with what I'm hearing. Not a bad turn around in a couple of nights I think. I need to run REW, get the drivers run in, and get it all EQ'd. I need to borrow the camera before I can get some more pics up, but for now I'm just getting used to it. Initial thoughts are that I'm incredibly pleased. Depth seems at least a match for my old ultra, but its extra power is shining through and its doing things even the Ultra couldnt. Sound quality is certainly more of what I'm looking for so happy with that as well.

I'll run some graphs soon and post them. Once I'm sure its doing what I want I'll then get on with starting the finish.
 

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Elite Shackster
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Discussion Starter · #10 ·
OK, ive had a chance to run a quick graph. This is pre Audyssey as audy just keeps giving me a speaker error result for the sub

Below, in this order is:

1. Response Graph
2. Response graph Including phase response
3. Waterfall
4. Response with an after EQ predicted response included (dotted line)
5. The BFD EQ filter set (auto filters, not manual)

I dont think it's too bad when Ive just plonked it in its spot and looked at what its doing. Hopefully I can get Audyssey running and see what that does. Ive certainly got enough room to play to get it flat to 10hz, but I dont think its to bad to start with given its an un-eq'd sealed sub.

Still some work to do, but I'm quite happy with how things are going so far. Now I need a BFD before considering shelling out on an AS-EQ1

Thoughts?

graph.jpg

graph with phase.jpg

waterfall.jpg

predicted response after eq.jpg

Filter set.jpg
 

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Dan,

Pretty impressive mate. Is that WinISD because if it is it looks different to my version. When you did the BFD filters did you let WinISD do it or was that maually done.

One thing I noticed on your BFD filters is that is alot of odd 1db boosting all the way along and I don't see why you would need any where that many filters. I also understood it, that it is best to use the least amount of filters. I originally had to use 10 filters on mine but reduced it to 7 filters. Do it manually, your get a better result.

cheers

Graham
 

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Elite Shackster
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7,142 Posts
Discussion Starter · #12 ·
That is REW. I used the auto eq option. I guess a lot of small filter adjustment suggests ones with a tight Q value. I'll get more into it when I actually get a BFD. Until then I just need to run the drivers in to account for response change over time, if it happens.

I have a question for the smart eggs out there. Currently Audyssey is detecting the sub with a speaker error result, and I cant get it working. I'm not sure if the opposite phase is causing it between the drivers. Anyone got any ideas?
 

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Elite Shackster
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7,142 Posts
Discussion Starter · #13 ·
OK, got Audyssey working. Here are my post Audyssey Graphs, wit what would be the makings of a natural house curve if I can fill in the 30 hz dip. I'll give it a couple couple weeks and then get on with finishing the cabinet at which time pics will follow. For now I'll leave you with these:

post audy graph.jpg

post audy waterfall.jpg

post audy spectral decay.jpg

post audyssey impluse response.jpg
 

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Elite Shackster
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Discussion Starter · #17 ·
Cheers for the comments guys. I guess in the US it would be considered a fairly small sub, but in the UK there arent many people with larger ones (discounting the few IB's that are over here). Our rooms are generally smaller as well so I guess I would have to put the sub size into perspective to get an idea of how large the sub is comparatively speaking. My sub is about 180 litres, while my room is about 1100 is cu ft.

I took the new sub to a friends last night where I could give it some and gave it its first real full test run. The setup consists of a 3.2 meter wide screen running of a JVC projector, a Denon BR Transport hooked up to an Onkyo 905, and M&K SS150 speakers up front with the matched tri-pole surrounds. We put the sub in the known best position of the room which was between the center on right front speakers. We then ran Audyssey to sort out the EQ (and I consistently get very good results with this and really do believe in it) and cranked the volume on the 905 to 0.

We tried several scenes we knew well as well as a couple new ones. The test scenes were Iron Man, TDK, KFP skadoosh scene, Finding Nemo Darla scene, Star Trek warping and planet implosion, Transformers barrel roll and street battle, and the last few scenes from Cloverfield. Both my fiend and I were smiling throughout the whole 3 hours session. The sub is incredibly powerful, articulate and accurate. It plays with authority but also with subtlety no other sub I have owned has ever had, except perhaps an old Rel I had and loved (although massively outdated and weak on movie content). It really can jut punch you in the chest one minute, then plays some subtle orchestral music the next, then blow up in your face while still keeping composed. I now especially notice effects like distant rumbles have improved to such an extent I can hear stuff I never had before, and it can do those distant effects at the same time as in your face explosions while still keeping both effects separate and clearly audible in their own right. The results for me really are top dollar. Part of the tribute has to go to the drivers, which I'm very pleased with, but all in all I couldnt be happier with this build. I'm unsure if any of this has anything to do with the push-pull design, but I'm working on experimenting to come to a resolution on that one.

When I set out to build this sub I did it because I couldnt find a commercially available design I wanted and wanted to pay the asking price for, that I could demo and would do everything I wanted. I has an SVS PB13 Ultra sub, but had gotten a demo of a pair of M&K MX series subs. Off the back of that I basically decided I wouldnt settle till I had a sub with the performance the Ultra had, but with the sound quality I loved from the M&Ks.

I have to say, I feel like I have acheived my goals and then some, and in my room this sub has at least the power of the Ultra, which considering its a sealed sub isnt half bad, and it has the exact sound quality I was after. All in all a very worthy upgrade to what I had before, and honesty I dont know how I could improve on it in my room with the space available.
 

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Elite Shackster
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Discussion Starter · #18 ·
That's very nice extension right there, dude! Pretty good for such a 'small' box.

Have you cranked it yet to see what she'll put up with? :devil:
Some of that is due to room gain, and I knew I could expect that a little but even so I'm pretty pleased with it. REW Graphs show it flat to 5 hz, but I dont really pay attention to anything below 10. I think the extension is doubly pleasing given my sub is also a sealed one, I dread to think what it would have been like if I had gone ported tuned to something like 15hz. This sub naturally rolls off at about 34hz, so eq and room gain are playing their part, but IMO you need to factor your room into your system, which I think has happened nicely here.

BTW, Ive just noticed your own build. Those are some serious tubes youve built. Being from the UK those large build always fascinate me. They look great, well done mate :T
 

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Thanks alot! Being ported the don't extend as low as yours, but they have some headroom all the way down to tuning. :hsd:

I really like those slightly 'unconventional' builds. I've had a sealed push-pull sub before and it was great too. That was the Dali Helicon S600. The Soundsplinters are in a completely different league, though.
 

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Nice set-up! I went with a AV15X sub in a 200L with 18-2100 PR's in my very big room and I'm happy with it. I'm getting close to flat response from 15-100hz. Since you have a small room and very good room gain, you're response is great down low.
 
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