Well, I took apart some small desktop active speakers and found the driver fitted perfectly inside a 110mm sewage pipe. Cut off 1m of pipe, fixed them on the top, filled the pipe with pillow stuffing, and popped the tweeters in some overflow plastic pipe and curved them over the top. Wired it back up and... I am gobsmacked! The sound is just amazing compared to the old mdf boxes. I can't quite believe the sound.
Industrial alternative enclosures are my favorite, I mostly build speakers this way. PVC pipe and sonotubes are some of the best cheap diy enclosure materials. PVC is used to make the DIY LX mini which is highly regarded, parts express has a nice diy pvc project. Sonotubes for TL (or stepped/tapped horn) subs. While your at the hardware store pick up some concrete cinder blocks, they make great bookshelf speaker enclosures.
I have seen this attempted on a TL sub without good results, rattling/buzz at the coupler that got worse over time. A smaller diameter internal tube would have made for thicker concrete and might have helped but it would have been too heavy. The solution was same size tubes with sand instead of concrete, the exterior was covered in dense foam and canvas, the results were now good.
The simplest possible Transmission Line: 5.25-inch woofer glued on the top of a 125mm PVC pipe 150cm long, plus a small cone tweeter below, some damping in the upper quarter of the tube. PVC pipe on the wall, 4cm above floor.
Crossover: woofer directly, 2nd-order high pass for the tweeter.
In-room response (1/3 octave smoothed), with nice support from 40Hz room resonance:
Crossover: woofer directly, 2nd-order high pass for the tweeter.
In-room response (1/3 octave smoothed), with nice support from 40Hz room resonance:
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It IS working well - the proof is in the pudding, i.e. the measured frequency response. Augspurger TLwrx software says the cross-section area is OK for the woofer used. Of course, some other 5.25-inch woofer may need greater cross-section area.
The main reason for choosing the pipe OD diameter equal to this woofer was to be the simplest possible loudspeaker build, it doesn't need any other work or material for building this loudspeaker.
The main reason for choosing the pipe OD diameter equal to this woofer was to be the simplest possible loudspeaker build, it doesn't need any other work or material for building this loudspeaker.
Hi all.
This is not technically a full range speaker, but sewer pipe it certainly is... I built this around 2001 with parts I had. The 'woofer' is a modified Radio Shack 40-1197 (?) with added mass around the dust cap and cone painted with diluted white glue (not the surround!). Tweeter are a pair of Vifa D19TD-05-08.
The 'baffle' came from a leftover piece of melamine kitchen counter (cutout for sink). It is glued with JB Weld to the larger first section of PVC, acting as some sort of chamber for the speaker. Then the main tube has smaller diameter. Not seen on the photos is that the line exit is via a hole in the 3/4" plywood base that is smaller in diameter than the pipe, unknowingly implementing some kind of mass-loading. Whole thing is lightly stuffed with pillow stuffing. The line is deliberately longer than calculations would give for the stock small woofer.
Crossover is a relatively large inductor for the 4" modified speaker, tweeter protected by a 2nd order network (3.3 micro F, 0.33 mH around 5 kHz) attenuated by an 8 ohm L-pad. In other words, very inefficient. But in my then girlfriend's apartment, small living room (photos) with a 20 W/channel receiver I gave her, they made some nice music. Since she moved overseas, they are likely gathering dust in her parents' garage...
I might build something like this again, once hardware stores reopen: I have a few 4" drivers on order... Cheers!
--Christian
This is not technically a full range speaker, but sewer pipe it certainly is... I built this around 2001 with parts I had. The 'woofer' is a modified Radio Shack 40-1197 (?) with added mass around the dust cap and cone painted with diluted white glue (not the surround!). Tweeter are a pair of Vifa D19TD-05-08.
The 'baffle' came from a leftover piece of melamine kitchen counter (cutout for sink). It is glued with JB Weld to the larger first section of PVC, acting as some sort of chamber for the speaker. Then the main tube has smaller diameter. Not seen on the photos is that the line exit is via a hole in the 3/4" plywood base that is smaller in diameter than the pipe, unknowingly implementing some kind of mass-loading. Whole thing is lightly stuffed with pillow stuffing. The line is deliberately longer than calculations would give for the stock small woofer.
Crossover is a relatively large inductor for the 4" modified speaker, tweeter protected by a 2nd order network (3.3 micro F, 0.33 mH around 5 kHz) attenuated by an 8 ohm L-pad. In other words, very inefficient. But in my then girlfriend's apartment, small living room (photos) with a 20 W/channel receiver I gave her, they made some nice music. Since she moved overseas, they are likely gathering dust in her parents' garage...
I might build something like this again, once hardware stores reopen: I have a few 4" drivers on order... Cheers!
--Christian
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I keep finding stuff i didn’t even know i had. I will be putting something up on my forum, but your suggestion of pointing to it from Swap Meet is a good one, thanx.
I currently have the free stuff flowing off a big shelf, and there will be both stock & treated drivers available at good prices. And further reductions on ready to go demos & proof of design builds, some really cheap because you’ll have to come pick them up (i am thinking of Aiko, someone had already grabbed the proto Maeshowe, and includes 3 big shelf/book shelves). A few EnABLed singles for anyone looking for a replacement driver.
Virtual dumpster diving, i like that :^)
email me if you want to get ahead of others. Given the current plague it is easier/safer for all if i can ship the little stuff.
dave
I currently have the free stuff flowing off a big shelf, and there will be both stock & treated drivers available at good prices. And further reductions on ready to go demos & proof of design builds, some really cheap because you’ll have to come pick them up (i am thinking of Aiko, someone had already grabbed the proto Maeshowe, and includes 3 big shelf/book shelves). A few EnABLed singles for anyone looking for a replacement driver.
Virtual dumpster diving, i like that :^)
email me if you want to get ahead of others. Given the current plague it is easier/safer for all if i can ship the little stuff.
dave
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