11' ceiling, nice
Should be interesting. That 1 factor is going to mess with anyone's guesses.
dave
I figured that would make things a bit more interesting. Probably better than my current situation.
I am temporarily in a top floor loft apartment in an old converted mill with 16' ceilings. The wall where the speakers are placed right now tilts inward at about 20º and has two 8' tall garret windows. At one point when fooling around with speaker placement it sounded like Diana Krall was singing from the next room.
But in general, does the castle design limit distance from the wall?
(and everyone please note - due to WAF there will be no acoustic treatments other than normal furniture and art hanging on the walls in the new place.)
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I don't think so.
Inmy room, with the speakers undrt a sloped roof, they had to be out a certain minimum distance.
dave
In my more conventional room ( 8ft ceiling) , the Castle MTs are about 8" from a the rear wall, flanking a large picture window - so there'll be some diffraction of early rear wall reflections - and about 10 or so degrees of toe-in. The latter is something you'll likely want to play with a bit to dial in the imaging sweet spot.
Ausie stuffing and ply?
Have any of you Aussies used the 2400 X1200 12mm ply that Bunnings have in stock for $33 a sheet? The surface doesn't look bad at all but the existence of voids I don't know about. I had thought of using it and glueing some of their 3mm ply on both sides to bring it up to useable thickness for a set of Micro Towers. The alternative is to use 12mm particle board with the same 3mm ply glued to both sides. At least it is always void free in my experience.
What about stuffing? Jaycar have some which seems expensive and I don't know if it is OK or not. In the past I have used motor vehicle upholster's padding which seems to my untutored ears to be OK. Any alternatives?
Have any of you Aussies used the 2400 X1200 12mm ply that Bunnings have in stock for $33 a sheet? The surface doesn't look bad at all but the existence of voids I don't know about. I had thought of using it and glueing some of their 3mm ply on both sides to bring it up to useable thickness for a set of Micro Towers. The alternative is to use 12mm particle board with the same 3mm ply glued to both sides. At least it is always void free in my experience.
What about stuffing? Jaycar have some which seems expensive and I don't know if it is OK or not. In the past I have used motor vehicle upholster's padding which seems to my untutored ears to be OK. Any alternatives?
Worth a try. You will need to play with the tuning.
Or, if you leave thebottomoff, you have the original MT1
dave
Zia. Thanks for the reply. I don't mind glueing the thinner ply to the 12mm ply. I've done quite a lot of veneering so I have a ready made, substantial veneer press for larger sections and have gone thro' the process with one of Scott's Windermeres. Very heavy when finished! The only 18mm materials here at a reasonable price are particle board and MDF- neither of which seem to be favourably regarded by Scott and Dave. I've used them both in the past but would like to give the ply a try. Robert.
Robert,
How many plys in the plywood?
Except for issues with driver rebates, 12mm, with maximum bracing, would be fine, if the ply is of sufficient quality -- we have a pair of subwoofers (push-push SDX10) here that we did in 15mm BB just to see how far the concept can be taken (waiting for the 4 channel amp)
The act of adding an addiitonal layer will push you towards a higher quality material if done right (and with a press sounds like you are).
One ofmy gurus did extensive research into materials. He found that he wasn't happy with MDF, but very happy with a board he made from 7 layers of 1/8" MDF (he used a 10 ton press).
dave
How many plys in the plywood?
Except for issues with driver rebates, 12mm, with maximum bracing, would be fine, if the ply is of sufficient quality -- we have a pair of subwoofers (push-push SDX10) here that we did in 15mm BB just to see how far the concept can be taken (waiting for the 4 channel amp)
The act of adding an addiitonal layer will push you towards a higher quality material if done right (and with a press sounds like you are).
One ofmy gurus did extensive research into materials. He found that he wasn't happy with MDF, but very happy with a board he made from 7 layers of 1/8" MDF (he used a 10 ton press).
dave
There are 5 plys in the 12mm board and 3 in each of the 3mm. If I decide to go with the ply I will put the 3mm on both sides of the 12mm, to balance it. That will also give me a little more depth to play with when rebating for the speakers. I will also work to interior dimensions that you show for the enclosures, so the additional thickness of the sides won't make for a smaller enclosure. Robert.
If you have the press, i'd be tempted to just lay up 5 thicknesses of the 3mm...
The local Home Despot sells some 3/4" with 5 plies...
BB has 9 in 12mm, the new Murphy ply we are using likley more -- the 15 (13 plies) & 18 (15? plies) both do.
the triple laminate should be good, the dissimilar material in the middle will go a long way to increasing the damping.
dave
The local Home Despot sells some 3/4" with 5 plies...
BB has 9 in 12mm, the new Murphy ply we are using likley more -- the 15 (13 plies) & 18 (15? plies) both do.
the triple laminate should be good, the dissimilar material in the middle will go a long way to increasing the damping.
dave
Dave I have more confidence in getting a decent job with the 12 ply centre and 3mm ply on either side than glueing five of the 3mm plies into one. I've tried doing that on another job and found the resulting piece was somewhat warped. Possibly something to do with the fact that the ply is not top quality (hence its price). Plantation grown pine can do strange things when wet! I've used 12mm particle board with 3mm ply on either side without any problems, so would hope that the 12mm ply centre would be the same.
Dave. I'm part way thro' the build but am undecided about speaker placement. I rather like my Windermere placement of two EL70s facing outwards. If I do that with the Castles, how far apart should the speakers be on the forward facing baffle and how should the damping be fastened? Is a curtain from top to bottom, suspended diagonally OK? Should the bare inside faces also be covered? Thanks.
Robert - the other variation of the dual driver MT enclosures that we've built to date is the "true" bipole - 2 drivers in push/push configuration opposite sides. Each format has its advantages, but for ease of placement and spacious soundstage, I quite prefer the "castle" version. Of course we used CHR70s in the bipole, and dual EL70s in an MLTL certainly punch further above their weight class in the low frequency department than the CHRs. .
Sorry Dave, I thought that all the same sized enclosures, regardless of the speaker placement position were called Castle. I had thought of placing one speaker facing up and the other on the baffle, but liking the sound of the Windermere with both speakers facing forward, thought I could do the same with this enclosure. Not so? The holey brace placement would be more straight forward with both facing forward, but I can at this stage still put one on top.
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