has anyone made the box ,then wrapped it in some fairly stiff foam sheet product,then put another wood box around the foam,without nailing through it into the inner wood box,so as to keep the two wooden shells from touching each other?? i think it would be the ultimate "dead" box.
but sinse this is the 5th day i have been reading about speaker building,im not sure of the terminology of the parts yet.
new guy
roy
but sinse this is the 5th day i have been reading about speaker building,im not sure of the terminology of the parts yet.
new guy
roy
mounting the driver....
well im no expert. im not even informed enough to be a beginner. that said,id mount the driver to the front baffle as normal. and maybe back bevel the rear to a open wedge shape behind the driver.??
im guessing here,i dont realy know.
roy
well im no expert. im not even informed enough to be a beginner. that said,id mount the driver to the front baffle as normal. and maybe back bevel the rear to a open wedge shape behind the driver.??
im guessing here,i dont realy know.
roy
Stiff foam is not ideal. What is said to work well is sand between a hollow construction. It 'absorbs' the waves in the material better. Hm. nailing... ts, ts 🙄
Have you thought about mounting your fullrange driver in an open baffle, say 3' by 2'? So a lot of problems just disappear...
Have you thought about mounting your fullrange driver in an open baffle, say 3' by 2'? So a lot of problems just disappear...
While on the subject of less traditional enclosures...
I am still at the beginner side of learning the basics in speaker box design, but I am starting to understand some of the concepts... needless to say, one would probably always have theoretical questions... and I don't have anyone to ask, but you...
So to get back to my question (or rather assumptions)
1) In a sealed box because there is nowhere for the rear sound wave (presure pulse) to go other than bouncing around inside loosing energy through heat, it has to have a dampening effect on the driver cone at the front, especialy higher frequencies. This might give more accuracy to the bass?
2) If I were to drop a driver in one end of an open pipe, the rear wave will move down, and out of the pipe, bounce on whatever is behind the opening and go forward to the listener, in the process reinforceing or reducing the sound from the actual driver front, depending on the distance the rear (soundbeam) traveled, before the waves met up. But it would not have a physicaly dampening effect (i.e. loose efficiency) to the same extent as a sealed enclosure, provided the pipe is not too long causing a heavy air piston.
3) I suppose this is the question part.
Lets say you reuse the pipe idea, BUT we change it to look like a gun silencer, ie. you have the long straight port, but it has many chambers of greater total volume than the port itself, which allows the presure wave to leave the tube, but reduces the effect of the actual sound waves exiting the rear.... So it would give the benefit of a sealed unit in that rear soundwaves do not interfere with front, but have the better efficiency of ported enclosures....
please point out flaws in my assumptions and perceptions... please don't mind my feelings, this is how I learn.
I am still at the beginner side of learning the basics in speaker box design, but I am starting to understand some of the concepts... needless to say, one would probably always have theoretical questions... and I don't have anyone to ask, but you...
So to get back to my question (or rather assumptions)
1) In a sealed box because there is nowhere for the rear sound wave (presure pulse) to go other than bouncing around inside loosing energy through heat, it has to have a dampening effect on the driver cone at the front, especialy higher frequencies. This might give more accuracy to the bass?
2) If I were to drop a driver in one end of an open pipe, the rear wave will move down, and out of the pipe, bounce on whatever is behind the opening and go forward to the listener, in the process reinforceing or reducing the sound from the actual driver front, depending on the distance the rear (soundbeam) traveled, before the waves met up. But it would not have a physicaly dampening effect (i.e. loose efficiency) to the same extent as a sealed enclosure, provided the pipe is not too long causing a heavy air piston.
3) I suppose this is the question part.
Lets say you reuse the pipe idea, BUT we change it to look like a gun silencer, ie. you have the long straight port, but it has many chambers of greater total volume than the port itself, which allows the presure wave to leave the tube, but reduces the effect of the actual sound waves exiting the rear.... So it would give the benefit of a sealed unit in that rear soundwaves do not interfere with front, but have the better efficiency of ported enclosures....
please point out flaws in my assumptions and perceptions... please don't mind my feelings, this is how I learn.
Hi,
That is mostly true for higher frequencies. resonances can stimulate the cone of the driver, passing 'through' to the listener in some way, especially with light membranes. It has not much to do with the bass. In bass, the enclosure acts as an additional 'spring' to the spider and surround, moving the Fs of the driver around (up) and increasing the Q.
2) A pipe is just a resonator on it's own, with one end coupled to the driver directly (TML) or through an addtitional volume ('spring') (ported) and the other end coupled to the room.
3) I like that idea! The small chambers should be damped. The response should be near infinite baffle.
Nordic said:
That is mostly true for higher frequencies. resonances can stimulate the cone of the driver, passing 'through' to the listener in some way, especially with light membranes. It has not much to do with the bass. In bass, the enclosure acts as an additional 'spring' to the spider and surround, moving the Fs of the driver around (up) and increasing the Q.
2) A pipe is just a resonator on it's own, with one end coupled to the driver directly (TML) or through an addtitional volume ('spring') (ported) and the other end coupled to the room.
3) I like that idea! The small chambers should be damped. The response should be near infinite baffle.
Hmm. On the original subject, this reminds me of something outside audio, but the lessons there could be applicable. I'm thinking of Colin Chapman's banned Lotus 88.
OK, for non-Formula 1 fanatics; Colin Chapman was the genius owner of Team Lotus, and probably the most creative car designer of all time. Back in the 1970s, he hit upon utilising ground-effect. He re-designed his then-current car with inverted aerofoil sections in the sidepods, and then shaped the underside so that the raipidly travelling air-flow from the front would suddenly open out into a wide area, reducing the pressure at a stroke. Side-skirts kept things sealed up, so that the car in effect was sucked harder to the track the faster it went. Nothing else could get near them. Over the next few years the concept was refined, but one thing always remained: these things pounded hell out of their drivers, because they needed massively stiff suspension due to the huge ground-effect being generated.
Cue Colin's fertile mind in coming up with a unique solution -the Lotus 88. This had 2 chassis. The outer chassis supported the suspension, engine and bodywork, whilst a smaller, inner chassis decoupled from the outer one suspended the driver in considerable comfort. Sadly, it never raced, the FIA governing body ruling it illegal on a highly dubious technicality (it was 'a moveable aerodynamic body') -real reason: it would have wiped out everything else in the field for the next couple of years.
Now apply this decoupling concept (and it's a good one, let's be honest) to a speaker, and you get something similar to what's mooted above, though I'd personally try mounting the driver to the inner box to keep in line with the F1 theme, and it would certainly go a long way to minimising external box resonance. Hey, you could even call it 'The Lotus'. Just a thought.
Cheers
Scott
OK, for non-Formula 1 fanatics; Colin Chapman was the genius owner of Team Lotus, and probably the most creative car designer of all time. Back in the 1970s, he hit upon utilising ground-effect. He re-designed his then-current car with inverted aerofoil sections in the sidepods, and then shaped the underside so that the raipidly travelling air-flow from the front would suddenly open out into a wide area, reducing the pressure at a stroke. Side-skirts kept things sealed up, so that the car in effect was sucked harder to the track the faster it went. Nothing else could get near them. Over the next few years the concept was refined, but one thing always remained: these things pounded hell out of their drivers, because they needed massively stiff suspension due to the huge ground-effect being generated.
Cue Colin's fertile mind in coming up with a unique solution -the Lotus 88. This had 2 chassis. The outer chassis supported the suspension, engine and bodywork, whilst a smaller, inner chassis decoupled from the outer one suspended the driver in considerable comfort. Sadly, it never raced, the FIA governing body ruling it illegal on a highly dubious technicality (it was 'a moveable aerodynamic body') -real reason: it would have wiped out everything else in the field for the next couple of years.
Now apply this decoupling concept (and it's a good one, let's be honest) to a speaker, and you get something similar to what's mooted above, though I'd personally try mounting the driver to the inner box to keep in line with the F1 theme, and it would certainly go a long way to minimising external box resonance. Hey, you could even call it 'The Lotus'. Just a thought.
Cheers
Scott
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