OK so what can you do with a 3” dia. Postal tube a couple of 5W resistors, a 2.2uF Solen Cap and a Mark Audio Tweeter #3 OR CSS ERT26?
Answer; Make a Frugal SuperTweeter like this:
Frugal by the fact they are dirt cheap to make and with the tweeters costing as little as £18.50UKP +VAT a pair (CSS ERT26 @ $13,00 each) and having a relative usable flat FR up to 30KHz makes it a candidate for a cheap SuperTweeter.
Yes the tube tweeter housing is simply a cardboard postal tube with a 12mm MDF disc cut with a hole-cutter to mount the driver on and albeit covered in some black SolarTex and the plastic end stopper spray painted matt black. Not showing in the second photo are the Red and Black 2mm sockets mounted on the rear that were installed after a rummage in my spares drawer for suitable hook-up connections. But they are these:
105-0802-001 WIMA | 10A test socket 2mm, red | 102-9276 | Welcome to RS Online
The above photos show the ST’s on the cradles that came with my (expensive) Fostex T90A’s and in keeping with the ‘Frugal’ theme I thought how can I make these cheaply? Answer; Buy a £1.35 broom handle from my local hardware store along with a couple of 6” nails! Yes nails. These just happen to be 6mm dia. And perfect for the job and more important cheap! The end result of the new cradle looks like this:
And the final finished ST’s sat atop a pair of Frugal Horn Mark3 with MA CHP70 main drivers looks like this:
For those that love the mellow and natural sound of this driver in these cabinets but bemoan a slight lack of top end sparkle then this is the perfect solution.
Answer; Make a Frugal SuperTweeter like this:
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.
Frugal by the fact they are dirt cheap to make and with the tweeters costing as little as £18.50UKP +VAT a pair (CSS ERT26 @ $13,00 each) and having a relative usable flat FR up to 30KHz makes it a candidate for a cheap SuperTweeter.
Yes the tube tweeter housing is simply a cardboard postal tube with a 12mm MDF disc cut with a hole-cutter to mount the driver on and albeit covered in some black SolarTex and the plastic end stopper spray painted matt black. Not showing in the second photo are the Red and Black 2mm sockets mounted on the rear that were installed after a rummage in my spares drawer for suitable hook-up connections. But they are these:
105-0802-001 WIMA | 10A test socket 2mm, red | 102-9276 | Welcome to RS Online
The above photos show the ST’s on the cradles that came with my (expensive) Fostex T90A’s and in keeping with the ‘Frugal’ theme I thought how can I make these cheaply? Answer; Buy a £1.35 broom handle from my local hardware store along with a couple of 6” nails! Yes nails. These just happen to be 6mm dia. And perfect for the job and more important cheap! The end result of the new cradle looks like this:
An externally hosted image should be here but it was not working when we last tested it.
And the final finished ST’s sat atop a pair of Frugal Horn Mark3 with MA CHP70 main drivers looks like this:
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.
For those that love the mellow and natural sound of this driver in these cabinets but bemoan a slight lack of top end sparkle then this is the perfect solution.
Nice little setup. Some felt on the faceplate would improve it- that hard edge is not a good thing acoustically.
Building A Budget (Super?) Tweeter Reaching the stratosphere! Article By Jeff Poth This would take more crossover work but would give you a better matched directivity profile.
Building A Budget (Super?) Tweeter Reaching the stratosphere! Article By Jeff Poth This would take more crossover work but would give you a better matched directivity profile.
Thanks for the link Badman. Interesting read.
Not sure what you mean by adding some felt on the faceplate?
These ST's are still in the experimental stage and though using a simple L-Pad to give a -7dB attenuation on the Tweeter #6 and a inline cap the results are quite impressive. I might make up another pair of tubes with the face plate cut to a 5-deg slope to match that of the front baffle the FH3's. But from initial listening it was found the position of the units had far greater affect on the sound rather than sloping the face by 5-deg. I think a smaller cap say 1.8uF may be evaluated next and perhaps add some roofing lead inside the cardboard tube to help stability and add some mass to the unit, as long as this doen't affect sonics.
But the guy that these were made for is very pleased with the results and I will pass on your comments and link to the web pages you posted.
Not sure what you mean by adding some felt on the faceplate?
These ST's are still in the experimental stage and though using a simple L-Pad to give a -7dB attenuation on the Tweeter #6 and a inline cap the results are quite impressive. I might make up another pair of tubes with the face plate cut to a 5-deg slope to match that of the front baffle the FH3's. But from initial listening it was found the position of the units had far greater affect on the sound rather than sloping the face by 5-deg. I think a smaller cap say 1.8uF may be evaluated next and perhaps add some roofing lead inside the cardboard tube to help stability and add some mass to the unit, as long as this doen't affect sonics.
But the guy that these were made for is very pleased with the results and I will pass on your comments and link to the web pages you posted.
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A little ring of felt surrounding the dome (not obstructing it) would absorb energy from the tweeter before it 'illuminates" the hard edge of the mounting flange. This tends to smooth response, off-axis in particular. It also has the benefit of absorbing some of the radial energy, making a better directivity (only slightly, this is a small effect in such an install) match to the fullrange.
I just ripped apart my very first speakers today
A cheap set of "Tuscany series 2" HT speakers
well apart from the great quality 10ohm bass and mid drivers as well as little 3" 3 ohm mids in the center channel i ended up with 5 x 1" 6ohm tweeters of non existant data and was curious for fun if i can use these in this set up if my speakers are different ohm without doing damage to my reciever?
even pulled out the "Quality" cross overs too
A cheap set of "Tuscany series 2" HT speakers
well apart from the great quality 10ohm bass and mid drivers as well as little 3" 3 ohm mids in the center channel i ended up with 5 x 1" 6ohm tweeters of non existant data and was curious for fun if i can use these in this set up if my speakers are different ohm without doing damage to my reciever?
even pulled out the "Quality" cross overs too
but isn't that tube the worst shape for difraction?!
"The absolute worst enclosure is a circular tube (cylinder), with the driver mounted in the exact centre of an end-cap."
Baffle Step Compensation
"The absolute worst enclosure is a circular tube (cylinder), with the driver mounted in the exact centre of an end-cap."
Baffle Step Compensation
DYNABLASTERTUNERS wrote:
I'm not sure why you refer to "worst shape" diffraction. Tweet No. 3 is a rear hermetically sealed design and the tube is also sealed and houses the L-Pad resitors and inline polyprop cap.
The simple 'Frugal' ST design was inspired by the likes of the Fostex T90A etc. as a cheap alternative add on top mount tweeter. So are you saying these are also flawed?
I'm not sure why you refer to "worst shape" diffraction.
Tweet No. 3 is a rear hermetically sealed design and the tube is also sealed and houses the L-Pad resitors and inline polyprop cap.The simple 'Frugal' ST design was inspired by the likes of the Fostex T90A etc. as a cheap alternative add on top mount tweeter. So are you saying these are also flawed?
When I asked my mate Chris for some feedback on how he was getting on with these tweeters, I got this reply. He is using these tweeters mounted atop his Mark Audio CHP70 Frugal Horn Mk3 speakers:
I'd call that a result
Broad grin isn't in it
In the time I've had listening to the FH3s with the CHP-70, I have come to the conclusion that for all that the CHP-70s are doing right, they are a little bit warm and cuddly at the high end of things - top end extension could do with a helping hand.
What these supertweets do do is redress the tonal balance with beautifully clean, non agressive top end sparkle.
This in turn, to quote a well known tea advert "allows t'flavour to flood out".
Bass has improved definition, and is seemingly deeper as well.
Rhythms are coming across better too.
The improvements are also not at the expense of that wonderful midband communication that the CHP-70 has - that is still very much there.
All in all I'm one very happy bunny Very Happy
_________________
Chris
I'd call that a result
according to the Article in the Link I've posted- yes
Mann chill, I really didn't meant to bother you, I just want to know/learn some things, that's why I've asked and not claimed
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chazdrumzalot wrote:
Yes it could provided the FR was extended sufficiently and the rear of the tweeter is hermetically sealed . A lot of tweeters out there only go up to 20KHz. To me for it to be called a supertweeter it must have a usable FR up to 30KHz or beyond.
Where the MA Tweeter #3 scores is both on price and usable extended FR and the fact it is a sealed design, so none of the sound is reflected back into the cabinet with all sound radiated forward. Hence the tube or box for the Tweeter serves no other purpose than to house the L-Pad resistors and the high pass(?) filter cap.
DYNABLASTERTUNERS You are not 'bothering' me. As I see things with a hermetically sealed tweeter none of the sound will be radiated back into the 'cabinet' it is all radiated outwards. So to me the cabinet shape - in this case a simple sealed tube - has no affect on the difraction. However, I could be wrong and I am sure more knowledgable members might wish to add their opinions.
Yes it could provided the FR was extended sufficiently and the rear of the tweeter is hermetically sealed . A lot of tweeters out there only go up to 20KHz. To me for it to be called a supertweeter it must have a usable FR up to 30KHz or beyond.
Where the MA Tweeter #3 scores is both on price and usable extended FR and the fact it is a sealed design, so none of the sound is reflected back into the cabinet with all sound radiated forward. Hence the tube or box for the Tweeter serves no other purpose than to house the L-Pad resistors and the high pass(?) filter cap.
DYNABLASTERTUNERS You are not 'bothering' me.
As I see things with a hermetically sealed tweeter none of the sound will be radiated back into the 'cabinet' it is all radiated outwards. So to me the cabinet shape - in this case a simple sealed tube - has no affect on the difraction. However, I could be wrong and I am sure more knowledgable members might wish to add their opinions.
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according to the Article in the Link I've posted- yes
I fear you haven't appreciated the fact that the Fostex T90a et al are horn loaded.
diffraction is on the outside
edges mostly
the closer to diaphragm, the worse it is
faceplate is rounded, close to dome surround
so that is taken care of nicely
next are your mounting screws
but not many care about those, even when it does matter
third is your faceplate edge
might have been nice to have a rounding there too
but may not matter that much
I haven't read the article mentioned, but I'm quite sure it concerns upper midrange mostly
edges mostly
the closer to diaphragm, the worse it is
faceplate is rounded, close to dome surround
so that is taken care of nicely
next are your mounting screws
but not many care about those, even when it does matter
third is your faceplate edge
might have been nice to have a rounding there too
but may not matter that much
I haven't read the article mentioned, but I'm quite sure it concerns upper midrange mostly
The point that dynablaster is trying to make is still unanswered. The diffraction that he is addressing is baffle step diffraction. As long as the operating frequency of the tweeter is high enough that 1/2 wavelength is shorter that the width of the tweeter faceplate, baffle step won't occur and Olsen's drawing do not apply. Edge diffraction is an entirely different phenomenon. Since the design under consideration is a dome tweeter, the edges will be illuminated well within the operating bandwidth and will be a consideration. The horn loaded Fostex designs are directional and do not illuminate the edges.
Bob
Bob
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