hi guys!
i'm planning to build a pair of 8" subwoofers for my home studio. i've done some reading on the subject over the last week, but there's a few things i'm not sure about yet. would be much appreciated if someone could help me out here! 🙂
some info first:
> i will use dsp to integrate, and eq correct these
> i'm listening at what most here probably consider low volume. i've measured with an SPL meter, and my max level comes in at around 65 dB(A)
> i'm not aiming for very low extension, i'll probably roll them off at ~38hz
> Dayton Audio RSS210HF-4 is the driver i'm planning to go with
> i'm planning to use 16mm thick mdf
> the speakers will be sealed
my questions:
1) i've read that the actual shape of the enclosure doesn't really matter, and that it's only the volume (liters) that matters. is that really true? if so, i'd like to go for a "tall" design since that would allow me more freedom when placing the speakers in my room. i've used an online tool to calculate an enclosure with "optimal" volume. it would measure 250mm x 250mm x 611mm, and the driver would be vertically centered.
2) to keep it simple, i'd prefer not to do any stuffing and/or bracing. do you think stuffing/bracing matters with small subs like the ones i'm planning to build, and more importantly at the levels i'll be listening at?
3) i have 2 channel poweramp lying around, that i'm not using currently. it can deliver 75W@4Ohms per channel. that should be enough for my low listening levels, right?
thanks in advance!
ps: here's a render of the enclosure design in question
i'm planning to build a pair of 8" subwoofers for my home studio. i've done some reading on the subject over the last week, but there's a few things i'm not sure about yet. would be much appreciated if someone could help me out here! 🙂
some info first:
> i will use dsp to integrate, and eq correct these
> i'm listening at what most here probably consider low volume. i've measured with an SPL meter, and my max level comes in at around 65 dB(A)
> i'm not aiming for very low extension, i'll probably roll them off at ~38hz
> Dayton Audio RSS210HF-4 is the driver i'm planning to go with
> i'm planning to use 16mm thick mdf
> the speakers will be sealed
my questions:
1) i've read that the actual shape of the enclosure doesn't really matter, and that it's only the volume (liters) that matters. is that really true? if so, i'd like to go for a "tall" design since that would allow me more freedom when placing the speakers in my room. i've used an online tool to calculate an enclosure with "optimal" volume. it would measure 250mm x 250mm x 611mm, and the driver would be vertically centered.
2) to keep it simple, i'd prefer not to do any stuffing and/or bracing. do you think stuffing/bracing matters with small subs like the ones i'm planning to build, and more importantly at the levels i'll be listening at?
3) i have 2 channel poweramp lying around, that i'm not using currently. it can deliver 75W@4Ohms per channel. that should be enough for my low listening levels, right?
thanks in advance!
ps: here's a render of the enclosure design in question
An externally hosted image should be here but it was not working when we last tested it.
Bad choice. Particularily with a woofer. 12mm (quality) plywood would be a better choice. It will need to be braced.
Mostly it doesn’t.
No stuffing means you will need a bit larger box, and no bracing is a mistake.
32 litres (by my calculation) is not small. I put braces in 2.5 litre boxes. Unless the box is naturally self-bracing (like some TLs or horns). In a subwoofer it is important to move box resonances up above the woofer bandwidth in frequency so they will not be excited. This usually means bracing (a vertical cross with the driver braced against the back panel. And light stiff material. MDF is neither stiff or rigid.
Should be sufficient. But how loudly an amplifier can play is as much related to how well the amplifier recovers from clipping.
dave
If your driving your amp into clipping then you need a bigger amp and speakers to match.
Any clipping at all isnt good.
That’s one way of doing it. But with its own set of compromises. And rarey what actually happens.
dave
dave
thanks for the input, i appreciate it!
noted. i'll go with braced plywood then 🙂 would there be any benefits (or downsides) from going thicker than 12mm?
noted. i'll go with braced plywood then 🙂 would there be any benefits (or downsides) from going thicker than 12mm?
Many of us normally recommend 18-19 mm no void plywood such as BB, Apple, Marine and bracing that ties all six sides together to keep it from 'breathing' plus forms a driver cradle/brace as sufficiently stiff enough that it will be resonant free in the woofer's pass-band.
Therefore the thinner the plywood or using other, lower stiffness [MOE] materials, the more bracing required.
Therefore the thinner the plywood or using other, lower stiffness [MOE] materials, the more bracing required.
Surely brace a lot, the more bracing, the better it will sound (less distortion due to panel vibration). And for this kind of subwoofer 18mm plywood is the minimum for me. 12mm is good enough for tops, but not for subs. Big power subs would even need thicker plywood for me (21mm to 36mm or 2 layers of 18mm plywood.
And for sealed, it's better to stuff the box good to avoid internal resonances. It's not crucial, but it helps to avoid issues. You can do that with a lot of materials, from expensive long hair wool to cheap fiberglass or rockwool of the right mass (45-50kg/m³). That Rockwool (Sono) costs about 25€ for a pack here and you will have to much for a pair of this cabinets.
And for sealed, it's better to stuff the box good to avoid internal resonances. It's not crucial, but it helps to avoid issues. You can do that with a lot of materials, from expensive long hair wool to cheap fiberglass or rockwool of the right mass (45-50kg/m³). That Rockwool (Sono) costs about 25€ for a pack here and you will have to much for a pair of this cabinets.
thanks again for the input!
i'll go with 18mm birch plywood then. i think i'll put some stuffing in aswell after all, maybe it can compensate for the loss of volume due to the now added bracing^^
i'll go with 18mm birch plywood then. i think i'll put some stuffing in aswell after all, maybe it can compensate for the loss of volume due to the now added bracing^^