Speaker cabinet sound - basics for noob

  • Thread starter Thread starter pure.fusion
  • Start date Start date
pure.fusion said:
So, to be extra specific here, does the above include the situation where I have part of the back of the "Open back" cabinet covered by wood? (About 1/2 of the back is covered in Blues Jr)
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That just makes the path length a bit longer, but only on one axis. Once the opening gets sufficiently large, it no longer acts as a port. Instead, you just get cancellation of low frequencies according to the size of the (non)enclosure.

I should do more research on ISO boxes but from what I can tell so far, to keep the noise level down, they are sealed. So there is effectively one big box, separated into two sections by a speaker with (i can't beleive this) no air flow between the two halves. Can you comment on this?
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If an iso box was designed that way, it would clearly change the low frequency response of the amp, because you are changing from an open-back design, which is effectively a baffle of limited size, to a design that is effectively either a very large baffle or a sealed box, depending on the volume involved.

Rather than try to get too deep into the theory, it's easier to just measure the amp inside and outside the enclosure and note the change in response. This doesn't have to be done at volume, as I stated acoustics are linear.
 
Right, so maybe the sweet spot is the key...

The question becomes, *how big* do you have to make the isolation box so that the *low frequency issue* becomes tolerable.

... and from another thread I was reading last week (can't find it right now) they were talking about how the lack of air in a sealed box makes the speaker behave differently (pushing, compressing the space), makes your amp work harder, and affects the microphone placed in front of it. I wonder how big the box has to get before these issues fall below the line of "squash my sound" ?

Just a quick search shows me...

https://www.youtube.com/watch?v=Q7IlwsPNvj0 - guy makes a box, no sample, so who knows what it sounds like. Maybe something like this guy's design, except larger.

How large? Maybe mshilarious could comment...

FM
 
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.. again guys, what's the best way to post mp3's ? Is there a site y'all use?

FM
 
Where did the cabinet designer go - he was like Obie Wan Kenobe flashing into existance to hand down some mystical knowledge from beyond... :p

Any comment on the large Iso box?

FM
 
pure.fusion said:
.. again guys, what's the best way to post mp3's ? Is there a site y'all use?

FM
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I use mediafire and megaupload.

Just google those two names and browse around a bit. You'll find something you prefer.
 
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