Multiple baffles and the effects

[Bigfootpete]

Does anyone know where I can find out the potential effect on the sound waves having multiple baffles will have?
Books websites etc...

I.e for a ported design where the sound is channeled like a transmission line - I know some of the effects of narrowing the baffle distance, but I'm just not sure of all the different effects.

Will I get a time delay effect? Will the sound be compressed and sound awful?

Or should I just try it and see?

I looked on the true audio website which has an article on reverb and echo but that didn't really help much.

[badman]

Not quite sure what you're getting at. Could you restate the question?

[leadbelly]

It sounds like you're calling the TL internals "multiple baffles". That's simply incorrect, and makes it hard to understand what you're really asking. Please clarify as badman says.

[Bigfootpete]

Oh, sorry - my mistake - I thought they were called baffles (duh, now I know baffles are the foam inserts that fit around the magnet).

I meant the internal wood bracing...
I want to use mutiple braces to channel the sound, but am unsure of whether this will have a detrimental effect...especially if I narrow the gap between the braces towards the port.

[wigginjs]

To my knowledge the common use of the word baffle as it relates to loudspeaker design would be the exterior panel of a loudspeaker upon which the drivers are mounted.

[The_Mox00]

I think he's talking about those enclosures that are used with the really efficient fostex horns.

[leadbelly]

Originally posted by Bigfootpete
I meant the internal wood bracing...
I want to use mutiple braces to channel the sound, but am unsure of whether this will have a detrimental effect...especially if I narrow the gap between the braces towards the port.

We are still not really sure what you're asking, if you could point us to some concrete examples that would help.

If you're suggesting, for example, that you have a design calling for a given box with an X diameter port Y inches long, but you also want to add internal braces with holes that are X diameter "channeling" the sound towards the port, then yes, those braces will impart audible resonances to the speaker and you will not get the same response.

[maxro]

If what you want is to figure out how to configure a transmission line, then I think you need to check out Martin King (MJK)'s mathcad worksheets at his website: quarterwave.com (IIRC).

Max

[Bigfootpete]

Maxro - if you have a look at my avatar you will see I have already built a TL.

My aim is to build my own design - but I would like to investigate what affects the bracing could have in advance before doing a trial and error.

Here's my design that I have so far - although I plan to add a bit more on the corners and use foam so there aren't any sharp edges.

[maxro]

So, the question is what kind of transmission efficiency loss occurs to the back wave as it has to pass thru several 180 degree turns. I'm not the one to ask on this, but my understanding is that for bass frequencies (<100Hz?) it shouldn't really be an issue. At higher frequencies there will be increasing attenuation, which can only be a good thing.

I think with MJK's worksheets you would have to model it as though it were a sectioned straight TL. I beleive there's some mention in his user guides about bends and their effects.

Max