Is it art? No, its Soldermizing!
Here is the Travesty 2.1 with its mighty TC9 tweeter and single mid "injection" port, totally eyeballed, using a CTS (Bose) type driver of unknown pedigree, a cull from my Marimba build of 2015. Sounds "OK", haven't done any fine tuning yet. I'll have to put a cover on it, or at least blankets over the drivers before I run sweeps. Right now its sort of a waveguide open baffle dipole two-way
Not optimal except for ease of construction, this made from various collected advertising signs. They are either 24x18" or 24x24". In fact, I only have to make two cuts (scores, actually) on two sheets, the rest is fold & stick with hot glue, Gorilla or the adhesive of your choice.
Not sure this build is worth worrying about a throat adaptor
Here is the Travesty 2.1 with its mighty TC9 tweeter and single mid "injection" port, totally eyeballed, using a CTS (Bose) type driver of unknown pedigree, a cull from my Marimba build of 2015. Sounds "OK", haven't done any fine tuning yet. I'll have to put a cover on it, or at least blankets over the drivers before I run sweeps. Right now its sort of a waveguide open baffle dipole two-way
Not optimal except for ease of construction, this made from various collected advertising signs. They are either 24x18" or 24x24". In fact, I only have to make two cuts (scores, actually) on two sheets, the rest is fold & stick with hot glue, Gorilla or the adhesive of your choice.
Not sure this build is worth worrying about a throat adaptor
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Errata
What, you would dare to question the details of my shoddy, slap-dash ***-embly techniques?
Correction: the current build, plus the outside "box" in progress, is completely done with panels of size 24x18"; the only 24x24 that would be needed is if I add a rear panel. One is already boxed, so now I can stuff fiberglass, old rags, Spanish Moss, old birds' nests, and whatever else is on hand for damping
What, you would dare to question the details of my shoddy, slap-dash ***-embly techniques?
Correction: the current build, plus the outside "box" in progress, is completely done with panels of size 24x18"; the only 24x24 that would be needed is if I add a rear panel. One is already boxed, so now I can stuff fiberglass, old rags, Spanish Moss, old birds' nests, and whatever else is on hand for damping
So I'm not the the only er, "protyper" after all!
While working my way through the Codex of Suitable Midrange I found this GM gem:
"FWIW, the POC I cobbled together used some old RS ~90 Hz Fs drivers with the baskets all cardboard/duct taped up and piezo tweeter horn in a foam core board horn and was rather surprised by its raw potential... proving to my satisfaction that the concept is a viable one even if done crudely and on the 'cheap'; though of course I don't recommend doing it as crudely/cheaply as I did except for experimental purposes as it took significant digital processing to tie it all together 'good enough' and couldn't play loud due to the super lossy horn construction."
A glimmer of hope for my current (literally) cut & paste project !
http://www.diyaudio.com/forums/mult...e-bandpass-mid-unity-horn-27.html#post2660888
While working my way through the Codex of Suitable Midrange
I found this GM gem:"FWIW, the POC I cobbled together used some old RS ~90 Hz Fs drivers with the baskets all cardboard/duct taped up and piezo tweeter horn in a foam core board horn and was rather surprised by its raw potential... proving to my satisfaction that the concept is a viable one even if done crudely and on the 'cheap'; though of course I don't recommend doing it as crudely/cheaply as I did except for experimental purposes as it took significant digital processing to tie it all together 'good enough' and couldn't play loud due to the super lossy horn construction."
A glimmer of hope for my current (literally) cut & paste project !
http://www.diyaudio.com/forums/mult...e-bandpass-mid-unity-horn-27.html#post2660888
Have you considered that....?
When a recovering (?) Bose 901 listener (myself) listens to even a DIY effort such as the Travesty 2.x, that it is probably an "upgrade", I mean, I actually am hearing imaging! Stuff in phantom center channel! Illusions of depth!
As you noted in your 2011 post, even your (or my current) POS mock-up showed the potential of the Unity/Synergy idea. The most expensive part of each speaker so far is the TC9, which cost what, maybe $20 each shipped?
Currently my wicked mind
is weighing the possibilities of canibilizing one of my six (more or less) working 901's, slaughtering one cabinet for its rich trove of drivers that might be affixed to the Travesty 2.x.
Or...? I'm sure this has been done already, the Bose 901 seems to have inspired infinite DIY efforts with the goal of something like "Surely I can make something better sounding than this POS? " Maybe as simple as the Mids for a Syginity waveguide
When a recovering (?) Bose 901 listener (myself) listens to even a DIY effort such as the Travesty 2.x, that it is probably an "upgrade", I mean, I actually am hearing imaging! Stuff in phantom center channel! Illusions of depth!
As you noted in your 2011 post, even your (or my current) POS mock-up showed the potential of the Unity/Synergy idea. The most expensive part of each speaker so far is the TC9, which cost what, maybe $20 each shipped?
Currently my wicked mind
is weighing the possibilities of canibilizing one of my six (more or less) working 901's, slaughtering one cabinet for its rich trove of drivers that might be affixed to the Travesty 2.x.Or...? I'm sure this has been done already, the Bose 901 seems to have inspired infinite DIY efforts with the goal of something like "Surely I can make something better sounding than this POS? "
Maybe as simple as the Mids for a Syginity waveguide
The main problem for using most 'FR' drivers is the half roll surround that severely limits compression loading and why the first Unity/Synergy I designed for others used an inexpensive Fostex 4" with an accordion surround since by then the cheap RadioShack or similar variants were long gone.
GM
GM
If DIY-ing just for a point source...
Based on my growing (mis-) understanding of the Unity | Synergy principles, for a quick and dirty DIY prototype such as I've made, my priority is or should be to experience a reasonable version of the experience of listening to a virtual point source.
It seems to me that this is easier to achieve without worrying overmuch about whether one's enclosure is a waveguide, a horn, both, or just some plastic panels hot-glued together
The efficiency of said speaker is not important. Having two (or more) drivers aligned in space, crossover frequency and phase and timing is. These last items are easily achieved with active EQ and measuring gear.
If the "real estate" of the waveguide permit it, why could my "midrange" be a huge powerful woofer? The constraints I must meet, as I understand them, are:
1. Midrange must reach at least to the desired x-over frequency to HF (I use 1000 Hz);
2. The port(s) must be with in the critical distance (1/4 wavelength) of the HF. For 1000 Hz this is around 8 cm.
3. The port(s) should be in a corner (optional) and the cross-section (diameter) of horn should <= highest wavelength (here, 1 KHz), about 32 cm.
Eyeballing, it looks like with certain at least rectangular horn shapes, one could easily fit one or two 8, 10, even 12 inch "mids" on two panels and still have one port within critical range of the apex.
What am I missing here?
Since my stock of "midranges" has run low, one of those in my Travesty 2.1 is buzzy, (I am loathe to try the MCM "pincuishon" driver and really would rather not pilfer a working 901...) there is a good chance I will be shopping for a pair of disreputable auto midranges at the local Wal*Mart or similar
Based on my growing (mis-) understanding of the Unity | Synergy principles, for a quick and dirty DIY prototype such as I've made, my priority is or should be to experience a reasonable version of the experience of listening to a virtual point source.
It seems to me that this is easier to achieve without worrying overmuch about whether one's enclosure is a waveguide, a horn, both, or just some plastic panels hot-glued together
The efficiency of said speaker is not important. Having two (or more) drivers aligned in space, crossover frequency and phase and timing is. These last items are easily achieved with active EQ and measuring gear.
If the "real estate" of the waveguide permit it, why could my "midrange" be a huge powerful woofer? The constraints I must meet, as I understand them, are:
1. Midrange must reach at least to the desired x-over frequency to HF (I use 1000 Hz);
2. The port(s) must be with in the critical distance (1/4 wavelength) of the HF. For 1000 Hz this is around 8 cm.
3. The port(s) should be in a corner (optional) and the cross-section (diameter) of horn should <= highest wavelength (here, 1 KHz), about 32 cm.
Eyeballing, it looks like with certain at least rectangular horn shapes, one could easily fit one or two 8, 10, even 12 inch "mids" on two panels and still have one port within critical range of the apex.
What am I missing here?
Since my stock of "midranges" has run low, one of those in my Travesty 2.1 is buzzy, (I am loathe to try the MCM "pincuishon" driver and really would rather not pilfer a working 901...) there is a good chance I will be shopping for a pair of disreputable auto midranges at the local Wal*Mart or similar
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Perhaps you are missing that 8" are already used in many of DSL's Synergy designs, and many others have successfully used 8", 10", and even 15" on various offset horns using a high frequency driver at the apex of the horn.
Using smaller mid drivers in conjunction with the larger drivers in a 3 way, rather than 2 way, allows higher crossover points, reducing the HF driver's excursion (and distortion), a more cost effective high SPL solution than using large format HF (or co-axial) compression drivers.
For home use, where (presumably) SPL requirements are 10-20 dB less than for PA use, single point source 2 way requirements are far easier to meet when using DSP.
Art
And imo this is what we should always be doing. 2 way down to schroeder. Sub. Boom. Done
ExactlyPete,
When are you going to get around to doing that with your SP1 horns
Art
If my above conjecture is correct, it opens up an appalling array of possible implementations of "virtual point source" speakers
Of course! If it can be built as a multi-way, it can be built as a multi-way horn, it will just be bigger since the 'cab' needs to be larger to get superior directivity and since it's a horn, the driver specs theoretically need to be somewhat different, though as Art noted, DSP solves a lot [all?] of the historically ~insurmountable technical problems.
GM
Schroeder frequency according to Charles Schultz
Welter, thanks for the clarifications. Yes, you are right no doubt.
For light-duty home use, especially with a tinkerer like me (at this stage, we are talking about a stolen (er, "recycled") advertising signs and hot-glue and (being generous) <$100 worth of drivers for two 24x24" "horns" ....
From all I've read, the two-way is the easiest to implement, especially if not using a compression driver ($$$) for the HF. I side with xrk971 and/or whomever got the idea to just use a regular (affordable) tweeter for HF -- say, the Typhoid TC9 or whatever it is
I'm with Pete: 2-way, down to Schroeder frequency (I even researched that) and cross over to my sub. Oh crap! I'll have to get another DSP as my MiniDSP has been conscripted for the synergy project
Welter, thanks for the clarifications. Yes, you are right no doubt.
For light-duty home use, especially with a tinkerer like me (at this stage, we are talking about a stolen (er, "recycled") advertising signs and hot-glue and (being generous) <$100 worth of drivers for two 24x24" "horns"
....From all I've read, the two-way is the easiest to implement, especially if not using a compression driver ($$$) for the HF. I side with xrk971 and/or whomever got the idea to just use a regular (affordable) tweeter for HF -- say, the Typhoid TC9 or whatever it is
I'm with Pete: 2-way, down to Schroeder frequency (I even researched that) and cross over to my sub. Oh crap! I'll have to get another DSP as my MiniDSP has been conscripted for the synergy project
Attachments
So....I am guessing the limitation on my Ch1 Peavey horn conversion will be the size of the mouth which is around 30" I sure would like to inject mids from 600 to 150 or at least 200hz and see point source from one horn from 150/200 up. I suppose Mr. Keeles horn loading (size of mouth) as opposed to the driver is going to be my limiting factor? I can easily run my compression driver down to 600 and inject a large mid or two right? Is the efficiency of the mids going to be an issue?
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Pete,
1) The mouth size and angles determine how low the pattern control extends. The flare rate determines how low the horn loads. Those "limitations" do not preclude mid/bass drivers sharing the horn.
2)Since your compression driver works OK down to 600 Hz, you are not limited to sharing the horn with "mid" drivers, you could use drivers capable of going as low as you want to extend.
3)The "issues" with efficiency are level matching and corrective EQ.
Sealed mids generally have very little excursion and high FS, they would not really be of much use sharing the SP1 horn, as you would only gain an octave (or so) extension below the HF driver.
Using only a single offset mid/bass driver will result in asymmetrical polar response, though with a crossover around 600 Hz, and the driver on the top or bottom of the horn, the difference in the vertical response may not be very noticeable.
Art
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