New Open Baffles (Gift for friends )

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diyAudio Member
Joined 2007
Started these a while ago after buying some close-out drivers from J***** and loosely based on Gainphiles first OB.

Woofers ar Jaycar 10inch, midwoofer is a cheap Taiwanese copy of Pioneer full range and the tweeter is also from J****** and unfortunately seems to have been deleted from range.

I had to buy a couple of chipboard sheets from Bunnings but every thing else came out of the shed

http://farm4.static.flickr.com/3137/3013562419_c6a4f60ea6.jpg?v=0

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http://farm4.static.flickr.com/3047/3014392820_1a0a7bd84d.jpg?v=0

As work progresses I'll let people know what they sound like in real baffles, but to start with I'll use the XO worked out on the foamcore trial baffle
 
diyAudio Member
Joined 2007
Yes they are ssort of hybrid. OB but with a sealed low bass, sort of .05 way; I'm rebuilding them for the second time with new/different midranges.
i'm lucky I have a soundproofed room with broadband and 30 Amps clean circuit to play with, but it;s not that big 3000 X 5100mm and sloping damped ceiling
 
diyAudio Member
Joined 2007
Crossover has been developed by listening only, based on components already in the shed.
Not the quickest and best way to do it but it works ( for me anyway) just takes time.
I started with low cut off on the woofer then chose arbitrarilly the highest value inductor I had (9mH) used a calculated LR second order and then ajusted capacitor values until it sounded OK.
Luckily some of those old paper full range cheapies have a gradual rolloff with little peaking.
They were a little dull at the top end so I added a tweeter afterwardjust a 2uFcap in series.
Baffle was played with over a weekend or three until bass sounded the best.
The advantage of using foamboard for test baffles is the ease of playing with different baffle sizes and shapes.

I am so happy with the sound of these that I am going to start on a bigger version usinfg 12 inch woofers.
 
Yeh, when it's just slightly wrong it can be impossible. This is even the case when it measures quite flat but still sounds incorrect. But at least you get to this "nearly done" stage a lot more quickly by using a microphone. A simple electret capsule and Preamp kit is what I used ... very cheap and effective, and ARTA is basically free for light use.

Simon
 
diyAudio Member
Joined 2007
I have almost finished these speakers.
Unfortunately for me it rained, and I was working in the lean-to next to the BBQ, not drought breaking rain just heartbreaking.
The MDF soaked up moisture and the wet paint bubbled, so they have been sitting for a couple of months.
I have decided to finish them anyway and make new ones if my friends decide the bubbles in the paint are objectionable.
Had to make aa major change in the XO to remove some of the HF noise coming from the woofers.
XO is now second order on both woofer and mid, near enough good enough, sounds better at a distance which is good, speakers are for a big, BIG room.
Personally I'm worried that there will not be enough bass but as the current speakers in this room are "Sony" plastic boxes with a 5inch 'Subwoofer' I think the new owners will be OK with the poor cosmetics
 
diyAudio Member
Joined 2007
We did need the rain but why on the day I started painting??
Couple of things to solder up and then some more listening.
Had a very frustrating experience today , wasted almost an hour.
I was soldering up a few connections and nothing would take, solder was dark and grainy and frosted, and connections were brittle and poor.
Turns out I'd picked up a reel of "Lead-free" solder by mistake, damned awful stuff, hard to work with and won't mix with real solder, what idiot in the EU decided that lead solder was going to be banned?? Even further what idiot of an Australian bureaucrat almost made the same mistake over here.

Final pictures follow in a day or two.
 
diyAudio Member
Joined 2007
OK fellas, they are almost finished.
I had to add some little feet to tilt the baffle back a little and to increase stability.
Mid-range is a little forward, seems even after lots of listening and playing around the series cap in the mid-range section is a little too big, there is a couple of dB too much at around 250Hz, still listenable but not what I consider GOOD!!

Cross-over is a bit of a dogs breakfast, that's what I get for keeping it cheap.

They play loud enough but need an amp with some grunt, the Yamaha protection circuit comes on at around 2/3's volume.
Quick SPL at 2 Meters was 107dB too loud to be comfortable and some warble in the mids at that SPL.

I should play a little more but I'm tired of them already and need to finish packing for the house move.
Pictures on Flickr

http://farm4.static.flickr.com/3459/3212328184_dbd6bff163

http://farm4.static.flickr.com/3531/3212327612_9ea81ff718.jpg?v=1232435573

http://www.flickr.com/photos/25510659@N07/3212328184/in/photostream/

http://farm4.static.flickr.com/3501/3211478701_8bea090d4a
 
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