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  1. #31
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    Thanks Harry I appreciate you leaving me to my imaginary differences

    Purchased 10 ScanSpeak 12MU/x731T00 drivers yesterday. 6 of the 8 ohm and 4 of the 4 ohm versions. Planning to run two in parallel in each of the front three speakers.

    Been brainstorming in Sketchup on some "fairly out there" designs. Attached are a couple of the ideas I am working with. Nothing in concrete, nothing to even say it's doable...

    Should be fairly obvious why I have nick named the idea the "Jelly Bean".

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  3. #32
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    While I'm kicking the imaginary ball around I thought I might try a few variations...

    This time the drivers in the top cabinet are to scale (unlike the others)

    Working on the principal of keeping the accoustics right but separating the bass from the more delicate tweeter.

  4. #33
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    I'm genuinely pleased that you're getting so much enjoyment out of designing these speakers and spending big dollars! I really do hope that you aren't disappointed when you come to actually make the boxes, let alone when you first hear them.
    Harry

  5. #34
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    Thanks harry, I have set my initial expectations low as not to disappoint. When I built the last set of speakers I was very dissapointed when I first put then loosely together on the floor with some make shift crossovers.

    To be honest the drivers were brand new and the crossover weren't right, but little by little I tweaked the crossover until it started to sound right. By the time I had them in some nice solid cabinets with ports and padding they sounded amazing.

    So deliberately setting expectations low. Expect that with going digital it won't take as long to get the crossover right. Last time I had to juggle values around and solder and unsolder lots of parts, this time around it will just be a quick software adjustment.

    Had to laugh... I thought what if I add some top arms to match the bottom legs, then I can use them to further support the back arch.

    So I started drawing it up and realised that I have just drawn the same ugly man that my partner got while she was overseas. She bought this revolting CD rack made out of wood with this skinny African tribes man standing behind the CDs with his chin resting on the top, low and behold I subconciously drew the same thing I hate

    Edit:
    Added a photo of the ugly CD stand..

  6. #35
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    It's because of useless, and in your case gross DVD storage systems that I've started to collect timber to build one, a cabinet with doors about 450mm high with the storage system set back on top and will hold 90 discs. This design will avoid bending to select a disc.
    Back to your speakers, you mention "tweaking the crossovers" are you relying on your ears to judge a flat response, or have you access to test equipment. What type of crossovers are they, the ubiquitous Butterwoth filters with a 12db/octave roll-off?
    Harry

  7. #36
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    It has sentimental value to her... I did try to suggest that it wouldn't hold the bin lid open, but she wanted to keep it.

    Like yourself I am not a fan of CD holders that only hold a few CDs and are exposed. I try to keep all of my CD / DVD / BR out of the sun.

    I was using my ears back in the late 90's when I built them, and money was very tight (IT student). I have one of these coming (V1) in the next few days. Dayton Audio OmniMic V2 Precision Audio Measurement System 390-792

    The options available in the active crossover are numerous, the main types Butterworth, Lnkwitz Reily etc and does up to a 96dB slope, so there is no shortage of choice.

  8. #37
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    Once the test mic arrives, all that you'll be short of is an echoic chamber!
    Harry

  9. #38
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    That and 20 years worth of testing experience...

    Like all thing in life I will have to make compromises like using a couple of hundred dollar mic instead of a couple of thousand.

    The place i'm in at the moment is quite noisy and I have been racking my brains to work out how to get some kind of base level testing done, to at least get me in the ball park.

    Perhaps make some temporary accoustic dampened walls... don't know still working on that one.

  10. #39
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    I wonder what the chances are that your beloved will allow you to stick egg cartons on the walls and ceiling!
    Harry

  11. #40
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    Probably better than most She understand the obsession...

    Was thinking along the lines of geting some of those accoustic pads and fixing them to thin sheets of MDF and building something temporary. Kind of like room deviders, that way when I'm finished I can reuse the pads for the walls in the yet to be purchased home theatre room.

  12. #41
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    That sounds like a good compromise. About six years ago I gave away six free standing acoustic panels about 6' 6" tall to a studio in Morley.
    Harry

  13. #42
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    Just down at Bunnings getting some line trimmer chord and I had a quick squiz at the thin MDF sheets, the 6mm which are 2440mm x 1220mm might be already they seemed light enough to move around.

    The 3mm of the same dimensions seems a little wobbly and would need a fairly decent frame to stop it bending and flopping on the floor.

    Better half who was reading my posts over my shoulder just made a really good suggestion. She said I should get some of those foam wave shaped matress protectors that are used on top of the mattress to make it more comfortable.

    Probably a crappy substitiute for a decent bed, but might make a fairly decent acoustic deadener

    Comes in one piece and can you can get queen sizes...

    Online The Big Sleep Foam Underlay - Queen Discounts | The Big Sleep Foam Underlay - Queen | Online @ Deals Direct.com.au

    And she is ok with me hanging it from the ceiling

    How big would a chamber need to be? or more to the point how small could you make it and it still work?

  14. #43
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    don't mount your " high end(Hz)" speakers like that just yet , one thing i learnt from instrument making is " node points " , run the tweeter section at the hz it will play at , sprinkle salt on the surfaces , the salt will move to the least movement spot , those spots are where you mount them from

    but then again it might be better to grab them by the corners and deadern the most movement spot with a strong frame .to stop the "negative wave" from getting out

    an all thread running across the sides between the max points of movement ( shown from salt ), hold them solid ( same force on both sides ) , will spread the " node point " to a ring around it , at ,at least 1/4 of the strength, but stop the rod from resonating as well ( tube over it with rubber/ cork mounts to surface )
    how come a 10mm peg dont fit in a 10mm hole

  15. #44
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    Not game to get salt anywhere near the tweeter, they are so easily damaged that they say not to even put a fan near it, because the breeze can damage the element, and there is no way to clean it if something got in it.

    Think I will stick to the more traditional testing methods, just to be safe.

  16. #45
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    It may not be everyones cup of tea, but I think I am close to a design I want to use...

    Using the slice method discussed earlier, I believe the cabinet won't be anywhere near as complex as it looks. I figure this should be achievable with only a few templates.

    I haven't quite worked out how to cut the speaker holes in the front of the top cabinet, as the face won't be flat. I can't go from behind because of lack of clearance, and I can't really cut the idividual slice properly, so that only leaves making the cut from the front.

    Edit:
    Reminds me a bit of K9...

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