Sealed box frequency response

[ShagggDiesel 25]

Sorry for being a thread whore tonight guys but I got a chance to really sit down on my laptop and do stuff and not work through my phone.

ANYWAY

Question: Can there be a certain tuning for a sealed box depending on size? IE: If you have a 1^3ft box sealed, and a 2^3ft box sealed, would the frequency response be the same with both boxes with the same driver? I've always wondered if there was a way to get a sealed box to produce lower frequencies with a good amount of output without having to port. Pretty much every sealed box I've heard peaks around 45-60hz and doesn't hit lows (35hz and lower) well at all. I didn't know if there was some kind of formula or concept that would alter the response in a sealed box. I know that it's pretty much flat, but is it like that in ALL cases?

Just an idea I've been pondering on.. People ask me why their subs don't hit "low notes" good, and I reply with "you have a sealed box, a low tuned ported box would perform better." But then they usually ask why, and I'm stuck with a crooked face

[Shogen 325]

I'm pretty sure a sealed application can actually go lower than a ported.. Difference is the ported application "enhances" output at the specified frequency..

Also, I haven't looked far into it but I believe there is no correct answer for what sized sealed enclosure is better because each woofer has it's own range of sealed sizes... So really there is not actual answer to your question that could be solid IMO... I could be wrong but ported would "sound" louder but not "lower" than a sealed enclosure...

[ShagggDiesel 25]

Ok so I guess my question would be, could you get a sealed enclosure to produce the lower frequencies comparable to that of a low tuned ported enclosure as far as output goes?

[KU40 173]

No. Ported just has too big of an advantage in the 30-50 hz range (if its tuned in the low 30s like most are for musical listening). A larger sealed box will have better lows than a smaller sealed box, however.

Ported is white, large sealed is pink, small sealed is yellow. You can see that the larger sealed enclosure has a bit of an advantage than the small, but the ported completely trumps both until you get below 20 hz. Below 20 hz is the area where people say a sealed box can play lower. Unfortunately, 98% of music does not go that low, so it's useless in a real application.

[helotaxi 46]

Below 20 hz is the area where people say a sealed box can play lower. Unfortunately, 98% of music does not go that low, so it's useless in a real application.

Your hearing doesn't go that low either. If the recording does have content down there you feel it rather than hear it. Sealed can handle this but it takes a lot of excursion and cone area to make it happen.

The size of a sealed enclosure affects the system Q which is a description of the shape of the impedance curve but also describes the response to some degree. A lower Q system (bigger box) typically has smoother response and better low freq output but they suffer in the power handling department. IB systems usually end up in the low Q category. Higher Q roll off more steeply and sooner and can mechanically handle more power thanks to the higher box damping.

[Shogen 325]

ahh I see... That chart makes alot of sense KU.. Thanks for that visualization of frequency response..

[ShagggDiesel 25]

Thanks for the clarification guys! Is that program freeware or is it buyable somewhere? It looks pretty useful...

[Duran 387]

Thanks for the clarification guys! Is that program freeware or is it buyable somewhere? It looks pretty useful...

It's called WinISD.

[helotaxi 46]

www.linearteam.org

[ShagggDiesel 25]