I am building dipole speakers with Supravox 215 GMF 8'' midwoofer, with a TAD horn for the highs and upper mids.. In the design, this led to some complications due to the heavy weight of the TAD 4001 drivers.. With some 13 kg I had to use 3 layers of 12mm MDF layered with epoxy to get a reasonably stiff baffle (keep it from bending under the weight of the TADs), and it appears to be strong enough. However, to get the most stability, it would be best if the TAD driver could lean towards the wall (as shown in the attached picture). The baffle on the picture will get «fins» to both sides made out of plexiglass to get the baffle wider, I guess it will be around 60cm to 70cm wide when assembled. The horn will be mounted on the baffle in the big circle in front of the compression driver, poking some 10cm out in the air.
Now, will the ~20-30cm spacing provided by the TAD driver give sufficient space behind the dipole so that it'll work properly? Or will I have to find another way of supporting the baffles further into the room?
Now, will the ~20-30cm spacing provided by the TAD driver give sufficient space behind the dipole so that it'll work properly? Or will I have to find another way of supporting the baffles further into the room?
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Rocky said:
If you have access to Microsoft Excel download a copy of XLBaffle and model performance. Unless your bass driver has a lower Qts than I would guess, given the choice of an OB, 20-30 cm is probably going be a bit close. On the up side, wings may be unnecessary.
XLBaffle Download
phase_accurate said:
Very nice idea. I would definitly go for a single one at the centre of the backside. I can make a big fat one using layered MDF too
Check out my new active cables being constructed for the dipoles: Besides active filtering, they'll provide two gainclone channels of 5 watts!! All battery powered!!
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Re: Re
Dunno how they sound yet, as they have not yet arrived. Didn't even have a chance to audition any supravox stuff before ordering, so this is kind of casino.. Most reports i've heard gives positive feedback exept some comments about varying build quality.. Specs are great though..
From 150 cycles??? Maybe if mr.Linkwitz designed my baffles Planning on gettting mine down to some 50-60 cycles... Two meters also sounds like an awful lot of space... unneccesarily much space.. Can't really understand why they would say such a thing..
mbon said:
Dunno how they sound yet, as they have not yet arrived. Didn't even have a chance to audition any supravox stuff before ordering, so this is kind of casino.. Most reports i've heard gives positive feedback exept some comments about varying build quality.. Specs are great though..
From 150 cycles??? Maybe if mr.Linkwitz designed my baffles
Planning on gettting mine down to some 50-60 cycles... Two meters also sounds like an awful lot of space... unneccesarily much space.. Can't really understand why they would say such a thing..I meant the bog-standard supports used in photography, to support floor-standing spot-lights, mikes, etc. You, know, one upright rod with adjustable height, ending in three feet on the ground...
With that in the back, and two spikes/cones/whatever in the front (baffle) you can easily adjust the speaker at will.
I'd also consider a shelf connected to the baffle, as extra support for the TAD
I'd suggest two trapzeoid shaped wings on either side, ie X (the height), 20cm (the top), 40-60cm at the bottom, and then do a horizontal cross brace below the horn to support it and give a solid structure.
It would have the dual benefit of supporting the horn and extending the bass, without knowing how you're planning on EQing.
Cheers
Steve
It would have the dual benefit of supporting the horn and extending the bass, without knowing how you're planning on EQing.
Cheers
Steve
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With the baffle shown in your jpg 150 Hz is optimistic.
Rocky said:
From 150 cycles??? Maybe if mr.Linkwitz designed my baffles
With the baffle shown in your jpg 150 Hz is optimistic.
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one passive capacitor takes care of equalizing the horn (Radian diaphragm), crossover is to be active 4th order. I will add active eq to the woofer if it proves neccesary. As all my stuff is DIY, adding stages is no problem..
sfdoddsy said:
one passive capacitor takes care of equalizing the horn (Radian diaphragm), crossover is to be active 4th order. I will add active eq to the woofer if it proves neccesary. As all my stuff is DIY, adding stages is no problem..
The baffle shown in the JPG is the driver support only. It'll get wings. I made the baffle slim for asthetics, so wings can be transparent and WAF high. Better than living with a sq.m. MDF panelMagnetar said:
Some attenuation (and slowing) of the rear wave helps make near wall placement more possible.
With transparent wings, I'd go with a single relatively thin pole with something at the top to cradle tweeter, like the non-tripod supports that sports photographers use. That's as long as there aren't kids or dogs that could knock it over. If there are, you are going to need a support that goes quite deep since the baffle will be so top heavy.
Also, you don't want spikes or cones. Don't give up the free ride that the baffle/floor junction gives you.
With transparent wings, I'd go with a single relatively thin pole with something at the top to cradle tweeter, like the non-tripod supports that sports photographers use. That's as long as there aren't kids or dogs that could knock it over. If there are, you are going to need a support that goes quite deep since the baffle will be so top heavy.
Also, you don't want spikes or cones. Don't give up the free ride that the baffle/floor junction gives you.
Based on my own experience with my open baffle speakers I would say make the baffles a bit wider.
Mine are 104 cm high by 83 cm wide and go down to around 70 Hz with the Goodmans 201's.
As regards placement, they sound better the further away from the rear wall that you can take them. Mine are about one metre from the rear wall and sound better there than at 60 cm. For most of us not living in a palace, there is a limit to how far out into the room we can bring them so there will have to be some degree of compromise.
I made up some absorbant 'bags' of offcuts of foam to place behind the main drivers which also helps!
Mine are 104 cm high by 83 cm wide and go down to around 70 Hz with the Goodmans 201's.
As regards placement, they sound better the further away from the rear wall that you can take them. Mine are about one metre from the rear wall and sound better there than at 60 cm. For most of us not living in a palace, there is a limit to how far out into the room we can bring them so there will have to be some degree of compromise.
I made up some absorbant 'bags' of offcuts of foam to place behind the main drivers which also helps!
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