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Discussion Starter #1
I started poking around here cos' I'd got 2 subs cheap as they were clearance stock here in NZ and while they are built to a price I couldn't go past the deal and they have a low FS for the speakers I could afford that are available here.

Well, the plan started as an apprx 85L isobarik vented box for music use. When the speakers and amp arrived (amp from Apex Jr. in California) I grabbed the first bit of wood I had as the gear sitting there and not making noise was too much for me! I had a sheet of 22mm flooring chipboard so banged up a double layered 40L box real rough so I could run the drivers in and play with placement etc.

Ended up making two 200L vented boxes that weighed in at 110Kg before the paint was on and the drivers were in. I wanted to build in a reasonable fashion but still see how cheap I could get them all together for. Found 40mm (1 1/8") MDF for $40 each at the local hardware store that were surplus from a bigger order so I grabbed 4 or them. (18mm MDF is normally around $45-$50 NZ a sheet so that was an awesome saving. Used 4x2 for most of the bracing, a friend donated a heap of eggcrate foam and proper sound deadening fill so that and a lounge size peice of latex carpet underlay are held in with just under 2000 10mm staples. All the joints were glued and screwed with "no-more-nails" and 65mm 8Ga square drive screws. Used 6 tubes of the glue and nearly 100 screws.

The vent is 84mm ID PVC wastewater pipe 340mm long with flared MDF ends. I cut a towel in half lengthways and soaked it in waterproof PVA glue then wrapped it around the vent to add weight/kill any resonance and also as the vent is at one end of the longest sides (top + bottom) of the box so wanted to stop standing waves in the metre high space.

I'm running my mains (which will be replaced once new mains are done, they are the first speakers I ever build and I have re-stuffed them and re-worked the XO but are still cheap drivers and horns and could be better).

Will add pics as I get them on Photobucket. Didn't want to write a novel so ask any questions, post any comments etc. I will be doing an in room FR in the next few weeks when my mate with calibrated mics etc comes over but set by ear so they integrate well on cd's like Ryan Adams-Gold they sound fast and real. Playing a 14Hz tone at half amp power they will make the whole house vibrate, windows flexing 3/4 of an inch easy and the walls, door frames too and go down to 10Hz easy which is the lowest tone I have in WinISD.
 

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Discussion Starter #2 (Edited)


The first box.



The Port from the inside/back before stuffing, the rest of the bracing etc.



Test fit of speaker.



Subs and mains in lounge room. Along with toys abondoned by the kids who had migrated outside by then.



The left speaker and sub. The mains are a horn tweeter and two 8" woofers crossed at 1350Hz, 6dB / Octave.
 

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Discussion Starter #5
Thanks. My shameless plug worked eh.

They are listed as 12mm one way which seems about right. Have played tones and moved them nearly an inch without them sounding strained. They are cheap but the motors seem ok, just heavy cones as far as I can guess. They play low well but don't like being crossed over above 60Hz, I run them crossed at 45Hz which blends well with my mains.

Yeah, I was aiming for around 14Hz and the panel amp is supposed to cut off at 12Hz but I havn't noticed it get any quieter down to 10Hz.

I wanted to get the same colour as the walls but some white came up so I used that and MDF router dust in some of the coats of paint. About 10 coats in total. Kinda limited in what I can do as I don't really have the means to purchase an EQ so it's all box. Happy with them though, very "live" sounding and faster sounding on a kick drum than I expected. Nice rich tones too. Track 8 on The White Stripes-Elephant, comes alive! I'm loving them thats for sure and the whole system cost me less than $1200NZ which was the goal. Now I've done the XO's for the mains etc could be replicated for under $1k NZ (~$800USD) which lined up next to something from a department store at the same price is amazing value in my book.

Thanks to everyone on the forum for proving to my wife I'm not a lone nutter! There are nutters all over the world who want massive distortion free listening in their lounge.
 

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Discussion Starter #7
I was going to run the one amp and speakers isobarik but with the test box the sound stage was pulled considerably by the sub placement and I decided to quit trying to make low tones with a small box with these speakers so two boxes was the way to go.

I used the Apex Jr, "Apex Senior" amp which is the exact same one available through Jaycar here in NZ but Steve at Apex Jr offers a modding service on these amps. They are normally 6dB boost @ 35Hz and 18Hz corner. Mine has been altered so no boost and supposed 12Hz corner but as I said in the last post plays 10Hz fine. Funnily enough the amp cost the same if I drove to the store here or paid Steve for the amp + mods +6kg of priority airfreight to my door!

Since I have changed my plan as the trials went on and now have two boxes I am planning to order another amp as funds allow so I can run stereo subs which fits with my end plan of replacing the noisy cheap amp I have now with two monoblocks per channel so basically a tri-amped 2 ch setup.

To get rid of the messy cd shelves and to save my dics from damage as lots are signed or limited release I have installed a 500gig internal hard-drive on my pc to store my music at full res and want to back that up with an optical capable soundcard > Denon 2ch (or maybe 6.1 by the time I actually do it) Preamp > the 6 separate amps. Not sure if I will stay with hand build XO's as I love the satisfaction of hitting on that golden combo but also want to know more about EQ's at different stages. Would be cheapest and most "bang for my buck" using a digital XO on the PC but really need to learn more before I can make that call.

Once the new drive is running I will download the REW and pick up a decent mic. My drive is full at the moment so no room for stuff to play with.
 

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Just stopping in to complement a project well done. They blend in really well with the room. Congrats!
 

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Discussion Starter #10
Just stopping in to complement a project well done. They blend in really well with the room. Congrats!
Thanks, I'm kinda brutal with the finish normally as most builds have been for mates to practice DJ'ing with so bare MDF is all good. Just the insides that count. As I am using budget gear and want to go low these things were gonna have to be given the room they asked for so I kinda used the "hiding in plain view" approach.

Nice idea mate!
Probably won't help for killing port resonances, but a keeper for future reference when working with thin / metal ports!
Hey Collo! A fellow Jaycar'er. Yeah I meant the sound getting through from the box not port resonance, sorry. My terminology is all outta whack but my heart is in the right place, hehe. As the box is over a metre high inside I didn't want a standing wave so the port being on the bottom, wrapped in the towel and then a few wraps of the latex carpet underlay with a bunch of cable ties is there to stop the sound going through the wall of the port (not that I am aware if it is or isn't an issue or have tested to see if the deadening actually makes a difference but hey) I figured the bulky padded irregular lump on the floor would kill the standing waves.


Have talked to my buddy with live sound set-up gear today, he is coming over next wednesday AM to do a room sweep and have a listen. I'm listening to them right now. Really good! Bass guitar not overpowering but not lost either. I love how these are intergrating with my mains, with no EQ and the whole thing one solid unit I don't know what I would have done if they didn't!

Now to build a power amp that is quieter than the noisey cheapo I'm running at the moment
 

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Discussion Starter #11
Also built into the design the speaker playing to 1/2 (or is it 1/4? how close to the floor before that comes into play?) space and the port playing to 1/8 space as its kinda tucked in it's own little nook there
 
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