Calculating Range Of Enclosure Frequencies

[Beanz]

arnt the bandpass boxes good on sum subs and not all ?

[aznboi3644]

Hoffmans Iron Law dictates frequency response

[Neo_frog]

Hoffmans Iron Law dictates frequency response

That's not quite what he's looking for.

I think that program will do you good as far as seeing your frequency response. That's honestly the best way to do it... You could really apply everything in car audio to graphs and seeing it helps put everything into perspective.

[aznboi3644]

If you know about Hoffmans Iron Law it has everything to do with his first post.

[Neo_frog]

If you know about Hoffmans Iron Law it has everything to do with his first post.

Is there is a way to tune your box so it plays a broader range of frequencies? Like from 28hz to 45hz? I understand big subs do better (have more authority) on the lows, and smaller sub are better for higher end bass. But is there a way to compromise for the size of sub woofers when tuning the box, so the enclosure can play more frequencies? Like if i wanted to go with 2x 15's, that i know will do well in the lower end, tune it to like 34hz... will it be able to hit the lows as good as some 12's tuned to 30hz because the 15's are bigger? if so, then it will also be able to sound just as good or better on the higher end bass, b/c its tuned higher right?

Also if it's possible can more experienced enclosure builders and designer's give me a specific tuning and the range that specific tuning of the enclosure will be able to play? I understand that all subs are not made equal, and sq subs will sound better then regular subs and what not. I am just a general estimation:

example:

12inch sub/ tuned to 32hz/ will play: 28hz-38hz

understand??

if not leave questions so i can be more specific when answering them.

All that law shows you is the relation of box size, efficiency, and cube of f3. It has nothing to do with what he asked. You can't use that law to determine a flat response from a box design. But maybe a general idea of how to power and how big the box should be.

[aznboi3644]

All that law shows you is the relation of box size, efficiency, and cube of f3. It has nothing to do with what he asked. You can't use that law to determine a flat response from a box design. But maybe a general idea of how to power and how big the box should be.

Hoffmans Iron Law

"You can have low end extension, high efficiency, or small enclosure size. Pick two."

OP asked how to play a BROADER RANGE OF FREQUENCIES. Well lowering the low end extension is BROADENING the range of frequencies the subwoofer will play. Small enclosure size...everyone knows a small enclosure is not going to play as low as a bigger enclosure. Is playing lower frequencies better BROADENING the range of frequencies the enclosure will play? Of course...same way that you can lower the frequency range the enclosure will play by tuning higher...you gain efficiency but lose low end extension...unless you make the enclosure larger...

And how does this not have anything to do with Hoffmans Iron Law???

[FYI-Future-Star]

Good post fellas I can see myself learning from a friendly debate

[Neo_frog]

Hoffmans Iron Law

"You can have low end extension, high efficiency, or small enclosure size. Pick two."

OP asked how to play a BROADER RANGE OF FREQUENCIES. Well lowering the low end extension is BROADENING the range of frequencies the subwoofer will play. Small enclosure size...everyone knows a small enclosure is not going to play as low as a bigger enclosure. Is playing lower frequencies better BROADENING the range of frequencies the enclosure will play? Of course...same way that you can lower the frequency range the enclosure will play by tuning higher...you gain efficiency but lose low end extension...unless you make the enclosure larger...

And how does this not have anything to do with Hoffmans Iron Law???

You are completely correct in that post. I'm not arguing what the law is or how it applies.

But someone cannot, having only that law handy, design a box that has a wide, flat response. You're correct when you say that lowering your f3 will "broaden" the range it will play by either adding power, size, etc.., but that's only because subs are limited to what they can effectively reproduce in any enclosure. A 6.5" speaker in a sub box would act as if it were in an infinite baffle application. Dropping box size would raise the f3 making the speaker reproduce a "broader" range of frequencies.

It works either way, but you are not wrong. Not many know of the law, but they do at the same time. We all know that a bigger enclosure will play lows better. And smaller boxes require more power to compensate for lack of efficiency. If you look at all the equations and "pretend" to raise and lower values on either side, you can see how Hoffman's law applies. But even using THOSE equations will not help you design a box with a flat response.

And I might have just figured out where we're missing each others' points. He said "broader range", and I read that as "flat response". So our ideas about the question might be conflicting.

[Neo_frog]

Good post fellas I can see myself learning from a friendly debate

I love debating with someone who knows what they're talking about. But glad I could give my input.

[FYI-Future-Star]

i love it