http://wyrdone.org/projects/hometheater/subwoofer.html
I want to build a sub using these items.
Dayton Loudspeaker 12" Titanic MKII dri
Cerwin Vega CVT-300S 300W Plate Amplifier
Mainly because of cost. I was thinking of copying this design but was not sure if it was good or not. Aesthetically it looks good to me, but I'm not so sure about sound. According to Dayton a 3 cu ft ported enclosure works well with the MKII. I was thinking about using these plans but modifying them to make a 2 cu ft sealed enclosure as specified by Dayton. Any thoughts? Also, does anyone know how low of a frequency I will be able to reach. I'm not able to use WinISD right now (not at my own computer). Also these plans describe a double thick mdf cabinet. Would it be better to make it double thick or use braces? Please let me know. Thanks.
I want to build a sub using these items.
Dayton Loudspeaker 12" Titanic MKII dri
Cerwin Vega CVT-300S 300W Plate Amplifier
Mainly because of cost. I was thinking of copying this design but was not sure if it was good or not. Aesthetically it looks good to me, but I'm not so sure about sound. According to Dayton a 3 cu ft ported enclosure works well with the MKII. I was thinking about using these plans but modifying them to make a 2 cu ft sealed enclosure as specified by Dayton. Any thoughts? Also, does anyone know how low of a frequency I will be able to reach. I'm not able to use WinISD right now (not at my own computer). Also these plans describe a double thick mdf cabinet. Would it be better to make it double thick or use braces? Please let me know. Thanks.
All sounds pretty sensible to me.
Though I'm not keen on the internal heatsink on
the Cerwin Vega amp, this seems a better bet :
http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=300-794&DID=7
How low it will go depends on your room gain.
But I'd stuff the box 100%, not 50%.
Fb will be around 36Hz which is low.
Bracing is much more effective than increasing wall thickness.
Checkout the subwoofer plans and documentation at Adire
Audio, specifically the sealed Shiva 54litre (2cuFt) plans.
🙂 sreten.
Though I'm not keen on the internal heatsink on
the Cerwin Vega amp, this seems a better bet :
http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=300-794&DID=7
How low it will go depends on your room gain.
But I'd stuff the box 100%, not 50%.
Fb will be around 36Hz which is low.
Bracing is much more effective than increasing wall thickness.
Checkout the subwoofer plans and documentation at Adire
Audio, specifically the sealed Shiva 54litre (2cuFt) plans.
🙂 sreten.
sreten said:
Just don't put the braces dead centre as is often shown in Adire plans -- a brace right down the middle is the least effective place to put it.
A really good speaker/amp deal is the Stryke/Lambda SAE1204 and the big ApexJr plate amp.
http://www.apexjr.com/speakerstuff.html
about half-way down the page. I have yet to see pictures that do justice to this woofer.
dave
Dividing a resonant surface in two will just shift the resonant frequency higher.
I dont really recommend bracing, I believe any properly made and joined box doesnt need it - it just uses that precious internal volume.
Jesus, I hate misinformation.
The middle is almost the best place to put the brace, though
slightly offset from the middle is better for full range speakers.
Raising the remaining resonant frequencies is only half the point,
the resulting box stiffness to resist low freqency pressure is far
superior to thicker cabinet walls.
And they take up less volume than thicker cabinet walls.
The point for a sub is to raise wall stiffness and move resonance
higher and futher away from the passband of the subwoofer.
IMO trying to slightly offset the braces is not worth it for a sub.
🙂 sreten.
planet10 said:
sreten said:
Ok, thanks for all the help everyone. I've decided to buy the combo from Apexjr.com. The SAE 1204 and amp are in my price range. I've also decided to build a box according to Adire Audio's specs (2cu ft). This will be my first real build (I've ordered a pair of BR-1s but the cabinet was already made). Any hints or helpful advice on constructing the enclosure would be much appreciated. I am planning on using a circular saw, router, and an electric sander. What do I use for cutting the round hole? I have a dremel too if that matters. Do I need anything else? Would a table saw be worth investing in? Last question I have is how to I make the inset to make the speaker mount flush? What tool do I need to cut the wood out? Please let me know. Thanks for all your help again. I really appreciate it.
sreten said:
What misinformation? You say it right there... slightly offset is better, slightly offset and at an angle is better.
The idea with a brace is that it pushes the panel resonance/bending frequency up in frequency to such a point that it is not excited.
Putting a brace dead centre creates two panels with identical resonance signatures (and is placed such that it does nothing to stop the 1st harmonic of the unbraced resonance). Moving it off centre kills that 1st harmonic and gives you panels with 2 different signatures so they even less likely to get excited. Angling the brace creates a trapazodal panel which is even harder to get going.
dave
planet10 said:
Have to agree but just stating the middle is the worst place
to put it is far from the truth. You are of course referring to the
second resonant mode of the panel, with a null in the centre,
the main panel mode is entirely suppressed by a centre brace.
But the other purpose of bracing is increase box stiffness, how
far the walls move under pressure from frequencies below the
internal resonant modes of the box. For a single brace in these
terms the centre of the panel is the best place to put it.
Resonant modes of the panels are not really an issue with
subwoofers, minimising secondary radiation to to lack of box
stiffness is. But i have to agree slightly offset from centre is
better it will only slightly compromise the box stiffness.
For full range speakers panel resonance is certainly an issue
and multiple braces are are the best way of spreading panel
resonant frequencies. Ideally due to the less than perfect
rigidity of the bracing the resultant modes interfere with one
another suppressing the Q of each sub-panel resonance.
An angled brace doesn't work quite as well as one would think,
the brace acts like a mirror reflecting the triangular panel to
give a virtual rectangular panel. For the same reasons triangular
sections in rooms suppress room modes much less than some
people suppose, they certainly do not prevent room modes.
🙂 sreten.
- Status
- Not open for further replies.