I found this from another forum who linked me to this discussion. This was some good reading so far. I have been a fan of the "artistic" look of the Cannon since I first saw one at Great Adventure in NJ in the 90's.
Fast forward a decade or so and I ended up coming upon some and couldn't refuse a good deal. Hopefully ill incorporate these into my decorating in my new place. Ill be moving in a few weeks and as you can see below the Cannons pretty much fill my current living space.
Seems that folks here have mixed feelings about these subs. Ill be happy to offer mine up for testing purposes to someone local.
Thanks for the info in the previous pages and my current question is what kind of amp would y'all recommend to power 1-2 of these? No way my house needs 4!
Jason
Fast forward a decade or so and I ended up coming upon some and couldn't refuse a good deal. Hopefully ill incorporate these into my decorating in my new place. Ill be moving in a few weeks and as you can see below the Cannons pretty much fill my current living space.
Seems that folks here have mixed feelings about these subs. Ill be happy to offer mine up for testing purposes to someone local.
Thanks for the info in the previous pages and my current question is what kind of amp would y'all recommend to power 1-2 of these? No way my house needs 4!
Jason
As I've mentioned before, I was extremely disappointed with the low-frequency performance of the small Wave Cannon I built. I'd originally used a 4" dual-voice-coil woofer with a Fs of 100-ish Hz, and followed the assumption that the longer of the two tubes should be tuned to Ftl = (Fs/2). However, when I took a quick ground-plane measurement of my small Cannon, I noted the low-end rolloff was beginning to occur at around 80 Hz, though the longer tube was tuned to about 50 Hz.
My suspicion was that the assumption that the Fs of the driver should be chosen to be twice the longer tube's quarter-wave frequency was an incorrect one. So, experimentally, I ordered an MCM 55-1854 aluminum-cone 4" woofer, which has a Fs of 54 Hz, almost exactly the long tube's tuning frequency.
After substituting in the new driver and being careful to seal up any air leaks, the performance of the enclosure is surprising. I can't believe I'm hearing this much output over the enclosure's bandwidth (45-180 Hz) from just a 4" driver, and I'm certain that the 55-1854 driver in a vented box wouldn't be able to approach the same output through the midbass that this enclosure is capable of, though further up in its range it does get a 'thudding' sound.
There are still a few limitations, though. First of all, the 55-1854 is excursion-limited by its voice coil instead of by its surround and spider, so it's not very tolerant of being overdriven, though I found a 40 Hz low cut to resolve this fairly well. Secondly, the small piston area of the 4" driver still tends to be the design's Achilles' heel -- there's still a need for judicious use of the 'level' control on the bass module's amplifier, to avoid voice coil bottoming.
So, the assumption that a driver with a medium or high Fs is preferable bites the dust. There may be some lowering of the driver's Fs, but that would be heavily dependent on the ATCR, much like the throat reactance of a bass horn. In the case of my Cannon, the ATCR is approximately 1.
My suspicion was that the assumption that the Fs of the driver should be chosen to be twice the longer tube's quarter-wave frequency was an incorrect one. So, experimentally, I ordered an MCM 55-1854 aluminum-cone 4" woofer, which has a Fs of 54 Hz, almost exactly the long tube's tuning frequency.
After substituting in the new driver and being careful to seal up any air leaks, the performance of the enclosure is surprising. I can't believe I'm hearing this much output over the enclosure's bandwidth (45-180 Hz) from just a 4" driver, and I'm certain that the 55-1854 driver in a vented box wouldn't be able to approach the same output through the midbass that this enclosure is capable of, though further up in its range it does get a 'thudding' sound.
There are still a few limitations, though. First of all, the 55-1854 is excursion-limited by its voice coil instead of by its surround and spider, so it's not very tolerant of being overdriven, though I found a 40 Hz low cut to resolve this fairly well. Secondly, the small piston area of the 4" driver still tends to be the design's Achilles' heel -- there's still a need for judicious use of the 'level' control on the bass module's amplifier, to avoid voice coil bottoming.
So, the assumption that a driver with a medium or high Fs is preferable bites the dust. There may be some lowering of the driver's Fs, but that would be heavily dependent on the ATCR, much like the throat reactance of a bass horn. In the case of my Cannon, the ATCR is approximately 1.
FWIW, my take on BWC design and DJK's folding it up to add a resonant node: http://www.diyaudio.com/forums/showthread.php?postid=1046340#post1046340
GM
GM
I am going to run a few experiments. I have a number of Vifa M22WR-09-08 drivers. One is in a properly designed ported enclosure and goes down to 35Hz. I intend making a folded cannon with the other M22 and then doing some testing and comparing.
I have both LMS and CLIO measuring systems at hand. My measurement room is 9*6*5 metres.
Suggestions are invited for how to measure and compare these two.
After this I will then compare various drivers, M22WR vs Morel MW267 and a response cs2366. I have these to hand.
Over to you.
I have both LMS and CLIO measuring systems at hand. My measurement room is 9*6*5 metres.
Suggestions are invited for how to measure and compare these two.
After this I will then compare various drivers, M22WR vs Morel MW267 and a response cs2366. I have these to hand.
Over to you.
In both cases they are out of phase by half wavelength. I acknowledge that the canon first radiation is a quarter wave behind everything else but i still can't see the difference unless you dont want the front of the woofer firing into the room. That could be handled a number of different ways. Could you explain further please? Thanks in advance.
It's years and years since I read the article in one of the Australian Pro Audio mags and crunched the numbers myself with multiple sine waves drawn out longhand and geometrically summed.
I crunched the numbers and could see where in the bandpass things subtracted or added. As to the info in the patent by Bose Re: Fs and all the rest, I have no idea. I suspect muc hof the patent info relates to how far Eq can be utilised to obtain a tolerable response from a cannon which is too short to function correctly at the frequencies required.
the sine waves make for good maths, the listening tests tend to bear out the bandpass gains. beyond that, I'm fresh out of input.
I crunched the numbers and could see where in the bandpass things subtracted or added. As to the info in the patent by Bose Re: Fs and all the rest, I have no idea. I suspect muc hof the patent info relates to how far Eq can be utilised to obtain a tolerable response from a cannon which is too short to function correctly at the frequencies required.
the sine waves make for good maths, the listening tests tend to bear out the bandpass gains. beyond that, I'm fresh out of input.
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