The "met" speaker cabinet would have the same issue you're currently facing - the cab design follows the driver selection. What you need is an enclosure you can throw anything into and it's still going to sound good.
I dont have the experience to be able to suggest such an enclosure, perhaps others do.
If I were to "take a swing" at that idea - with some hope of not whiffing - I'd say such a cab would be one of Dave's Frugels. But even then you'd have to know your driver size to pick which one. Perhaps the small one would "just work" with those Audi speakers you're considering harvesting, depending on how big they actually are.
You could always upgrade to a more appropriate driver later, when you get around to making payment options available. That's what's nice about a cab that works with a series of drivers; you get some latitude in playing around with it in the future. Hope this helps,
I dont have the experience to be able to suggest such an enclosure, perhaps others do.
If I were to "take a swing" at that idea - with some hope of not whiffing - I'd say such a cab would be one of Dave's Frugels. But even then you'd have to know your driver size to pick which one. Perhaps the small one would "just work" with those Audi speakers you're considering harvesting, depending on how big they actually are.
You could always upgrade to a more appropriate driver later, when you get around to making payment options available. That's what's nice about a cab that works with a series of drivers; you get some latitude in playing around with it in the future. Hope this helps,
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When you put it like that then any speaker i use will be mismatched so i'm just as well off to throw in a random speaker and rock on. any other course of action is going to be almost certainly expensive and a waste of money.
I didn't realise how difficult the maths of how all the parts connect would be when i started. I doubt i would have started.
I didn't realise how difficult the maths of how all the parts connect would be when i started. I doubt i would have started.
I had a look at the audi speakers today, they originals were gone and had been replaced with 8 inch sony xs-f1720 140w 4ohm units 35w drive.
I had to lift one unit out by the small tweeter, it fractured in my hand. the wire fell out of the tweeter was all burned up, no enamel left on it.
I'm thinking of hot glueing the tweeter wires down inside the plastic mounting so they don't rattle.
Now that i know they've been overdriven i will disconnect the other tweeter so that i do not damage my amp. both speakers read around 5 ohms but when i measure at the electrolytic that feeds the tweeter it is 17 megohms, not healthy.
The plastic cones are in good shape though.
I'm going to go ahead and mount these. their flange allows them to mount from the outside of the cabinet.
I had to lift one unit out by the small tweeter, it fractured in my hand. the wire fell out of the tweeter was all burned up, no enamel left on it.
I'm thinking of hot glueing the tweeter wires down inside the plastic mounting so they don't rattle.
Now that i know they've been overdriven i will disconnect the other tweeter so that i do not damage my amp. both speakers read around 5 ohms but when i measure at the electrolytic that feeds the tweeter it is 17 megohms, not healthy.
The plastic cones are in good shape though.
I'm going to go ahead and mount these. their flange allows them to mount from the outside of the cabinet.
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Well, actually, no - a random speaker likely wont work all that well. Disappointment will likely follow.
The whole point of DIYAudio is to use your brain instead of your wallet. Good sound can be had inexpensively, if one is willing to take some time and think it through, or research what others have accomplished well.
There's many giants here who've attained this; you're certainly welcome to stand on their shoulders - so to speak - it's pretty much the whole point of the forum.
Look around some more, pick an inexpensive driver you read people have been successful with (I'm pretty sure were talkin' <$20 US ea) and choose that driver's corresponding cab design. Make it in 6mm steel. You'll probably be delighted; what better use of your money can there possibly be?
Best, going forward.
If embarking on a middle school science experiment in acoustics, I think you’ll want to design the main carcass of enclosure to accommodate easy swapping of drivers on removable wood sub-baffles. A simple rectangular opening with provision for gasket sealing should suffice. Methods of securing the baffles to the metal shell can be as elaborate as you want, but when I did that with plywood enclosures, I used threaded insert fittings and machine screws.
Pipe have constant lenght while wavelenght of sound is changing by frequency.
As result soundwaves from driver and pipe exit will be sometimes at phase and sometimes at antiphase giving bumps and notches depending on frequency.
By stuffing the part above driver its possible to smooth some of them, but not all. Bump around pipe resonating frequency and big notch in upper bass will remain, resulting in boomy and hollow bass.
Some people consider that "warm na airy" and like the sound and thats why Voigt pipes have their following.
Yeah i will probably do the frugel-horn next. not for a while though i've a lot of work to catch up on. i liked the diversion for a little while though.
I made a string of mistakes, the sides pulled in while welding and i had to take 5mm off the edge of the front panels to get them to fit. I dropped some iron absent mindedly and split the cone on one speaker but hot glued it back again, then i forgot to truncate the top of the triangular side panels and i had to lop 2 1/2 inches from the top in order to have material to weld to. that wouldn't have been the end of the work as i guess i could have moved the speaker port to compensate but the cabinet resonates like a tuning fork. i can hit it with a hammer and it gives a tone for a full twelve seconds. i can talk into the port and i hear my voice coming out like tubular bells.
the project is a disaster, but now you know. friends don't let friends make steel speaker cabinets.
someone once wondered what effect johnny cash used on folsom prison blues to give the reverb. there was no effect, it was all the steel in the jail. about all this is good for is to emulate that sound.
this is fail of the week for me.
Not much point in mounting the speakers. I'd have to mount them on the inside as i couldn't remove enough material with the welder without damaging the holes to mount them from the outside. it would be difficult, i'd have to tie string to them and pull them up through the bolt holes.
I made a string of mistakes, the sides pulled in while welding and i had to take 5mm off the edge of the front panels to get them to fit. I dropped some iron absent mindedly and split the cone on one speaker but hot glued it back again, then i forgot to truncate the top of the triangular side panels and i had to lop 2 1/2 inches from the top in order to have material to weld to. that wouldn't have been the end of the work as i guess i could have moved the speaker port to compensate but the cabinet resonates like a tuning fork. i can hit it with a hammer and it gives a tone for a full twelve seconds. i can talk into the port and i hear my voice coming out like tubular bells.
the project is a disaster, but now you know. friends don't let friends make steel speaker cabinets.
someone once wondered what effect johnny cash used on folsom prison blues to give the reverb. there was no effect, it was all the steel in the jail. about all this is good for is to emulate that sound.
this is fail of the week for me.
Not much point in mounting the speakers. I'd have to mount them on the inside as i couldn't remove enough material with the welder without damaging the holes to mount them from the outside. it would be difficult, i'd have to tie string to them and pull them up through the bolt holes.
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Lining them with a constrained layer should calm that ringing and you can get to deciding whether it is good.
(off-topic) Looking at these flat panels reminds me of explosive hydroforming. Explosively hydroforming a steel sphere - YouTube
(off-topic) Looking at these flat panels reminds me of explosive hydroforming. Explosively hydroforming a steel sphere - YouTube
As was suggested, you can make a "supra-baffle" - which is just a square piece of plywood adapting the speaker to this box's cutout hole. Screw the wood piece to your metal enclosure with machine screws, then (with the hole cut in the plywood for the speaker nice 'n circular), use wood screws to mount it. I'd bet you have a jig saw and some plywood hanging around.
That way you wont have to fish the speaker into place. Keep going on it - you'll want to hear how they sound for all your work so far!
If they ring with music, there's still things you can do to make it better. Good luck!
That way you wont have to fish the speaker into place. Keep going on it - you'll want to hear how they sound for all your work so far!
If they ring with music, there's still things you can do to make it better. Good luck!
It's already been noted several times above that it is fully expected these will ring like a bell if you hit them. And it's also been noted that hitting a box is not a synonym for its behaviour when a drive unit is mounted in them.
The acoustic resonances you hear when 'talking into the port' are exactly what you would expect from an empty, unstuffed Voigt pipe. They are designed to be highly resonant pipes, acoustically (which is not the same thing as panel resonance). They require some stuffing above the driver at least. Of course, if you want to give up now based on incorrect assumptions and waste all your time without ever even giving them chance, that's your business. But if it was me, having got so far, I would
a/ Stop belting high rigidity metal boxes sans any damping whatsoever with a hammer & announcing that is a realistic representation of actual operating conditions with a small wideband drive unit
b/ Put some inexpensive damping above the drive unit location
c/ Shove some drivers in there and try the damn things out. What have you got to lose, other than an hour or so of time?
Top tip -if you can't get those ex-whatever speakers you've got going, get thee down to the local[ish] independent electronics component store. You know the type -sell lots of different types of wire, connectors, some computing components, cheap DJ lights -you get the idea. More often than not, these places tend to have, or be able to get, cheap loudspeaker drive units, and in many cases will have a couple of nominal whizzer cone fullrange units in there. They won't be great, but they often make a half-decent noise too. 'Eagle' is a common brand name in their catalogues. Probably set you back about £15 - £20 apiece for something you could try to shove into these, so not a catastrophically expensive exercise -and before anybody says anything about 'it's all right for people on a good salary': for reference, I currently earn £475 per month, total, and have been surviving on that for years, since I got shafted by my last 'employer' who I am still waiting to pay me for the work I did 7 majestic months ago. So I am well aware of what it is like to have very little money.
The acoustic resonances you hear when 'talking into the port' are exactly what you would expect from an empty, unstuffed Voigt pipe. They are designed to be highly resonant pipes, acoustically (which is not the same thing as panel resonance). They require some stuffing above the driver at least. Of course, if you want to give up now based on incorrect assumptions and waste all your time without ever even giving them chance, that's your business. But if it was me, having got so far, I would
a/ Stop belting high rigidity metal boxes sans any damping whatsoever with a hammer & announcing that is a realistic representation of actual operating conditions with a small wideband drive unit
b/ Put some inexpensive damping above the drive unit location
c/ Shove some drivers in there and try the damn things out. What have you got to lose, other than an hour or so of time?
Top tip -if you can't get those ex-whatever speakers you've got going, get thee down to the local[ish] independent electronics component store. You know the type -sell lots of different types of wire, connectors, some computing components, cheap DJ lights -you get the idea. More often than not, these places tend to have, or be able to get, cheap loudspeaker drive units, and in many cases will have a couple of nominal whizzer cone fullrange units in there. They won't be great, but they often make a half-decent noise too. 'Eagle' is a common brand name in their catalogues. Probably set you back about £15 - £20 apiece for something you could try to shove into these, so not a catastrophically expensive exercise -and before anybody says anything about 'it's all right for people on a good salary': for reference, I currently earn £475 per month, total, and have been surviving on that for years, since I got shafted by my last 'employer' who I am still waiting to pay me for the work I did 7 majestic months ago. So I am well aware of what it is like to have very little money.
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Ok, I'll try them out eventually. I was planning on using the speakers that got damp as they still have the foam gasket for internal mounting. could someone that has access to a voigt pipe calculator tell me where i need to move the speaker port to now that the lowther club of norway plan is 2 1/2 inches shorter. maybe it does not matter for a simple test but it will be painful for me to drag a cabinet up a flight of stairs, so i would prefer to fix it first. I can't really angle grind and weld in my bedroom, too much electronics and flammable material.
The nearest electronics store is 80km away. auto factors and commercial electrical supplies are all that i know of.
I'm not sure if i have a working jigsaw, killed my last one trimming sheet iron from a hayshed that was hitting the roof of the tractor.
You all mention the wooden baffle but it's not any simpler for me to construct than steel. I have a good selection of metal working tools.
The nearest electronics store is 80km away. auto factors and commercial electrical supplies are all that i know of.
I'm not sure if i have a working jigsaw, killed my last one trimming sheet iron from a hayshed that was hitting the roof of the tractor.
You all mention the wooden baffle but it's not any simpler for me to construct than steel. I have a good selection of metal working tools.
Sorry, I didnt get your last question.
Is pipe too long compared to plans or speaker hole isnt at right place?
Anyway, 2.5in will only make few percentage of difference in pipe freq. response which is totally negleable with random drivers.
Even if you designed it for particular driver it would be within driver manufacturing tolerance so you dont have to make any repairs.
I agree with others you should make some wood-based material adaptor and fit the driver from outside.
If you dont have plans to make that Frugals out of iron it will be nice practice of some speaker woodworking.
Is pipe too long compared to plans or speaker hole isnt at right place?
Anyway, 2.5in will only make few percentage of difference in pipe freq. response which is totally negleable with random drivers.
Even if you designed it for particular driver it would be within driver manufacturing tolerance so you dont have to make any repairs.
I agree with others you should make some wood-based material adaptor and fit the driver from outside.
If you dont have plans to make that Frugals out of iron it will be nice practice of some speaker woodworking.
the pipe is now too short compared to the plans.
original plans here Lowther Club Of Norway - The Voigt Pipe
state the internal length to be 180cm.
the internal length is now 173.7cm
This is because i added on 2x6mm to the width but my trigonometry wasn't up to scratch to figure out the length.
yes it was a huge mistake, and will change the taper of the pipe a little.
original plans here Lowther Club Of Norway - The Voigt Pipe
state the internal length to be 180cm.
the internal length is now 173.7cm
This is because i added on 2x6mm to the width but my trigonometry wasn't up to scratch to figure out the length.
yes it was a huge mistake, and will change the taper of the pipe a little.