An externally hosted image should be here but it was not working when we last tested it.
Here is an idea of a tricolumn speaker using the f88 (or other small speaker). I've designing it using the specs from the paper "Now,a tricolumn- build this efficiente column spekear" by R. N.Baldock. Two questions:
1. How to model it with Hornresp? Simply use parabolic sections? There are some discontinuities in the interfaces between the 3 cylinders (one of them is not a cylinder)...
2. Or just go for it with a thumbnail calculation based on the resonance frequency (L=c/(4*f)) and taper ratio of 1/3, height of the inner tube d=2*L/3 (part 2 of the paper)?
Thanks.
Last edited:
Hi being curious and all that, i cannot find the paper for the Tricolumn speaker. A link to them would be welcome. It's a technique form the fifties?
Here is the final tricolumn, sounds great!
Cheers.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Cheers.
Wow that is a lot of wooden rings to cut. Looks very nice. A driver on the end of a cylinder is one of the extreme examples of the baffle interference and diffraction. You will get a very rough peakyness from bass on up to baffle step frequency. But since listening 90 deg off axis and from reflected sound may not matter much.
Very nice looking project. Congratulations!
The original had the driver offset in the top baffle instead of centered, which would have reduced the edge diffraction issue. I can't tell from the picture whether this is offset or not. Anyhow, it's not going to be an issue when upfiring like that.
This appears to have been done as an 'ML-TL', unlike the original, which is simply an open ended offset TL with straight sections. (though the original is sort of mass loaded by the floor proximity) How did you end up modeling it?
The original had the driver offset in the top baffle instead of centered, which would have reduced the edge diffraction issue. I can't tell from the picture whether this is offset or not. Anyhow, it's not going to be an issue when upfiring like that.
This appears to have been done as an 'ML-TL', unlike the original, which is simply an open ended offset TL with straight sections. (though the original is sort of mass loaded by the floor proximity) How did you end up modeling it?
Last edited:
Thanks for your comments.
> Wow that is a lot of wooden rings to cut. Looks very nice.
First time with a CNC, simple and effective.
> ... from reflected sound may not matter much.
I do like the sound reflections in my living room, works nicely.
> How did you end up modeling it?
Actually I didn't, just followed the original plans with some mods.
The ML-TL vs TL was my simple way of solving the fixing of the 3 small legs that you can see in the picture above.
For lower powers (2W) it sounds good but for >2W the bass is too muddy and boomy... I think I'll change it to a simple TL in the near future (with a larger square base to hold the column).
Cheers.
P.S. (edit)
Taper ratio is about 1/4 and parabolic. The walls are 10mm thick and each ring has 18mm depth.
> Wow that is a lot of wooden rings to cut. Looks very nice.
First time with a CNC, simple and effective.
> ... from reflected sound may not matter much.
I do like the sound reflections in my living room, works nicely.
> How did you end up modeling it?
Actually I didn't, just followed the original plans with some mods.
The ML-TL vs TL was my simple way of solving the fixing of the 3 small legs that you can see in the picture above.
For lower powers (2W) it sounds good but for >2W the bass is too muddy and boomy... I think I'll change it to a simple TL in the near future (with a larger square base to hold the column).
Cheers.
P.S. (edit)
Taper ratio is about 1/4 and parabolic. The walls are 10mm thick and each ring has 18mm depth.
Last edited:
TriColumns built in 1972
I was idly surfing today and found you guys after looking to see if the audio diy world was alive and if column type speakers were still around. I am the happy owner of a pair of Tricolumns built to Baldocks design article 50 years ago using 9 inch I/D fired clay sewage pipes. I was working as an engineer at the factory so two clean pipes just fitted in my Morris 1000 van. Naturally we have had much family fun over the years telling lies about we had to get them in used condition and clean them out by hand.... they have always been known as the S**T PIPES. The drivers were simple 8" paper cones as per the spec and the internal piping was spare steel flue lining with fibreglass damping added to taste. We tried various wooden box alternatives over the years but always missed the very open natural sound that these give along with effortless lower end. They are superb for classical music. I suspect the top end could be better so plan B was to angle the driver mount and fit a tweeter but at 72 years old this would probably only benefit the cat. In a weak moment we let these go to a young nephew - this coincided with the punk era so they got lots of exercise - he loved them. When he moved to a small house we got them back with a rip in the tired drivers - he blamed The Stranglers. They now sport a pair of Visatron B200 which needed more padding to quell the stronger 1k peak but seem better at detail. We run the TV through them via the headphone output and a cheap 20W amplifier and when the alien starship hits the photon torpedoes even the neighbours duck.... Thank you Mr Baldock.
I was idly surfing today and found you guys after looking to see if the audio diy world was alive and if column type speakers were still around. I am the happy owner of a pair of Tricolumns built to Baldocks design article 50 years ago using 9 inch I/D fired clay sewage pipes. I was working as an engineer at the factory so two clean pipes just fitted in my Morris 1000 van. Naturally we have had much family fun over the years telling lies about we had to get them in used condition and clean them out by hand.... they have always been known as the S**T PIPES. The drivers were simple 8" paper cones as per the spec and the internal piping was spare steel flue lining with fibreglass damping added to taste. We tried various wooden box alternatives over the years but always missed the very open natural sound that these give along with effortless lower end. They are superb for classical music. I suspect the top end could be better so plan B was to angle the driver mount and fit a tweeter but at 72 years old this would probably only benefit the cat. In a weak moment we let these go to a young nephew - this coincided with the punk era so they got lots of exercise - he loved them. When he moved to a small house we got them back with a rip in the tired drivers - he blamed The Stranglers. They now sport a pair of Visatron B200 which needed more padding to quell the stronger 1k peak but seem better at detail. We run the TV through them via the headphone output and a cheap 20W amplifier and when the alien starship hits the photon torpedoes even the neighbours duck.... Thank you Mr Baldock.
