Vibe Audio Australia / AutObarn Maitland - Audio Demonstration Vehicle

5 years 7 months ago - 5 years 7 months ago #41 by Andy
The back wont be going on until the very end, right before turning it all on. I dont even think i will glue it for now, just some foam seal and alot of screws......this way i can always make improvements inside the box, or even reduce the box volume if i find that port area too small. The port walls are in, only 140mm deep but i think that it'll be tuned will be well low enough, ive crunched the numbers and here are some:

* 30 cubic feet gross volume
* 88.5 sq. in. of port area

Which means:

* 3.75 cubic feet per sub
* 11.05 sq. in. of port area per sub

Sealed the baffles in with resin today, poured a litre in each corner and painted all around the joins, also added another 32mm layer to each side panel, unfortunately the "leftover" bits were not the full 700mm, fell 50mm short :angry: The box is getting more solid now, weighs in excess of 250kg without the back panel (20kg). Need 5 guys to move the box around, i cant even slide in on the concrete myself anymore :smoke:

Added another 250 screws to the top and bottom panels.......i wasnt happy with "just" laminating them, if the start to separate once its bolted into the car im in for a whole lot of pain trying to get it back out and in again. So i thought the screws would be my insurance :silly:

I dont think im going to add the pine bracing to the baffles, they are REAL strong as it is now.....plus i dont want to inhibit the airflow to the front woofers even more than what it is going to be now.....hopefully i dont get any cone failures from the pressure they will be under.









Come on, you know you can almost smell the resin :laugh:


Just a quick teaser pic of a baffle full :P


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5 years 7 months ago #42 by Dylan
That port looks so tiny :P
5 years 7 months ago #43 by amcinstaller
it does. especially since that box is such big sexy :ohmy:
5 years 7 months ago - 5 years 7 months ago #44 by Andy
Stop, please......you know that was all an engineering nightmare of angles and crap, at one point there i thought the space left for the port was going to be like 40mm wide, im damn happy with 90mm :S

I can always reduce the box depth :P
5 years 7 months ago #45 by Dylan
You could have always split the baffles and put more angle on the row of subs near the port. :P
5 years 7 months ago #46 by Tezzating
Could have isobarically coupled the subs, done a 4th order bandpass and used a squash court door for the top of the box haha.

Demo cars are always inherently compromised for one reason or another.. like your sponsors top sub is a duel 6ohm coil and they wont give you the cheaper ones cos they want to push the top end gear

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5 years 7 months ago - 5 years 7 months ago #47 by Andy
Oh stop your whining.......you DID get a massive (bullshit big) Crown amp, did you not? :lol:

Finished adding the other 100 screws to the bottom panel and used the last litre of resin going over all the joins etc. Also mounted the batteries in their box and wired them up to the solid brass buzz bars :P





Im sitting on the fence at the moment with regards to fusing the amps......the runs to the monos will be like 50cm and the 4ch amps about 3 metres. Im having space issues in between the battery box / buzz bars and the enclosure rear / monos. If i did fuse them with ANL types i would need to extend the positive cable to a suitable mounting location for the fuse holders......most likely turning that 50cm into 80-90cm.


Its looking like i'll be done audio-wise in about 2 weeks, provided the other 2 monoblocks arrive in time.

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5 years 7 months ago #48 by Dylan
I probably wouldn't fuse the sub amp runs, but I would fuse the runs to the speaker amps.
5 years 7 months ago - 5 years 7 months ago #49 by zion187reigneth
I noticed andy that the guys have had their own suggestion about your sub box?
Well never again :beer:
With all new polygon shapes
im a firm believer that a box needs an array of polygon shapes(energy transmissions) on the inside of the box
Thats right polygon shapes, you heard it from me first!
Just when you thought box design was 101 style, nope , polygon shapes my friends, it changes the whole game!! ;)
5 years 7 months ago #50 by Andy
Yeah no, i wont be doing any polygon shapes.....the old clamshell is techinical enough for me :laugh:

On the mono amp news front, looks like my remaining monos wont be here till "mid" December now, but knowing customs they'll take their sweet time and probably wont see anything until the new year :(
BUT, could also be hitting Vibe up to swap out these monos for a single "Reaper" (10kw, 1m long) :rock:

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5 years 7 months ago - 5 years 7 months ago #51 by Tezzating
That guy must be pretty short if thats 1m long, didnt know they made 10kw amps in "The Shire" :evil:

Brass for the buzz bars ? I'd run alloy myself.

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5 years 7 months ago #52 by steveo
i got some alloy strips i can run to ya :-)
5 years 7 months ago - 5 years 7 months ago #53 by Andy
Just checked.......here i am thinking brass is more conductive than alloy :blink:

Oh well, im sure it'll be one of the things i change when hunting down 0.1s :laugh:

Ive added 3x M12 threaded rods to the enclosure, two bracing the top to bottom and one on the sides. I have that much tension in the rods there are distorted :laugh: I also started work on smoothing and flaring the port out, i cant fit any power sander in there (that i currently own - not buying another sander) so its all by hand.......and with 40+ degree days, not much is getting done :(
5 years 7 months ago #54 by Tezzating
Sounds like apprentice work to sand the port.

Hopefully they sell back that amp so you can have real power in there.. and you really should swap to alloy now :P. Corrosion in the Festiva's old copper bars used to cost 0.5+dB every time. Sometimes between events the only "tuning" would be to polish the copper and regain conductivity for a dB boost. That big big amp will demand alloy!

Buckling the M12's, not a good time ! Did you sleeve 'em with steel tubes too or just straight rods ?

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5 years 7 months ago #55 by Tezzating

zion187reigneth wrote: Thats right polygon shapes, you heard it from me first!
Just when you thought box design was 101 style, nope , polygon shapes my friends, it changes the whole game!! ;)


But his box isnt one of those shady Pyramid schemes, this design is based on the trapezoid..

I think your polygon idea is pretty close to my ported tube idea; minimal "dead zones" for increased flow potential.. sorta like pulse tuning a tubular manifold.

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5 years 7 months ago #56 by Andy
Have just spoken to the MD of Vibe Australia, he has confirmed there are no Reapers available and has been on the phone to every Vibe stockist in Australia trying to locate the remaining 2 Bass 1 monoblocks i require. Fortunately he has located 1 in QLD and one in VIC, both have been shipped straight to me :rock:

So, this confirms the original plan of 2 subs per mono at either 2 or 0.5 ohm. I have been advised to be cautious running them at 0.5, but we'll see :whistle:
Only around 4,000w RMS at 2 ohm (so 500w RMS per sub which is 550w RMS rated), im thinking around 6000w RMS at 0.5 (so 750wrms per sub).

Anyways, here's a few quick shots i took today.....









This is my "anti-vibration" proof solution for the threaded rods :lol:


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5 years 7 months ago #57 by Dylan
:O Is that neat wires I see in an SPL box?
5 years 7 months ago #58 by Andy
Yes, yes it is :laugh:

4 x 12AWG either side should be ok, the runs are only 1.9m. I'll terminate them on the bottom of each side panel with these:

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From there it will be 12AWG cables around to each monoblock.
5 years 7 months ago #59 by Dylan
That'll look rather neat. Considering the small power your running to each woofer it should be overkill really :D

This should look rather intimidating from the cabin once it's all said and done!
5 years 7 months ago #60 by Andy
Ignoring dig at my lack of watts :P

Yeah im thinking so. Im going to paint the baffles matt black and the port yellow to match the subs.

I still need to do a heap of work to the port, sanding and filling but its coming along ok.
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