Here's another build that shows a method of planning a synergy/unity. Not to deter you from your current plan, as
it will be much easier and I think is very likely to yield exc results much more quickly, but just to show you that a synergy/unity build is possible.
Klipsch K402 replica build - DIY Audio Projects - StereoNET
It only gets you half way there, because it does not include woofers, so really isn't a synergy, but helpful nonetheless for thinking through how to get started.
it will be much easier and I think is very likely to yield exc results much more quickly, but just to show you that a synergy/unity build is possible.
Klipsch K402 replica build - DIY Audio Projects - StereoNET
It only gets you half way there, because it does not include woofers, so really isn't a synergy, but helpful nonetheless for thinking through how to get started.
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Ha, looks like it. No, for one thing I notice that many unities run to 700Hz (or within an octave, anyway) so where's the down side? I also believe that a point source of either sort down to 700Hz followed by a properly implemented cross to a matching lower midrange is a good solution.
Not sure if we can draw much of a conclusion from it, but it's interesting to see the differences in wavelets of a shortened K-402 compared to the K-402-MEH from Chris.
See this post and the next one:
https://www.diyaudio.com/forums/multi-way/330741-preference-direct-radiators-27.html#post5731415
I'm sure Chris (Cask05) could tell us which one has his preference.
In another thread Chris showed the wavelet of a SH-50:
https://www.diyaudio.com/forums/multi-way/244508-monster-massive-29.html#post5707811
One can see the top end being clearest on the shortened K-402, but I wouldn't be surprised if the MEH sounds better due to having a more even overall balance. Curious to find out though.
All these ideas are valid within context of an MEH. Trade-offs are always part of a "coupled design" like the MEH, and I find them interesting to explore.
If you start with a full-range horn that holds its directivity to below 100-170 Hz (like the K-402 presently does in half or quarter space), then the problem of IMD is significantly alleviated in the woofer which is alleviated via employment of room boundary loading--like a corner horn does, except that you don't actually need the room corners to get directivity and LF extension). The K-402 picks up boundary gain with ease like no other horn that I've seen. This will likely result in a multi-part horn (to get it through the doorways) with a larger mouth in order to push the loss of directivity a bit lower in frequency. So it's not really the length of the horn that's important for directivity, but only its mouth dimensions in horizontal and vertical. The K-402 horn is only ~15" deep, but has excellent directivity control down to 40 Hz.
The use of an 18" or pair of 18" cones is enabled via compression loading ("slot loaded" due to the compression ratio of the cone area vs. the port area), the operating frequency range of the 18" woofers is actually significantly increased (with some regard for phase plug design--called a "frustum" in MEH terminology) for the high frequency end, and the low frequency end limits the peak-peak motion of cone due to the sheer size of the cone area(s). The tradeoff is efficiency, but not really IMD (i.e., you still get the clean sound of the horn-loaded bass drivers). This is an interesting tradeoff--directivity and low IMD vs. efficiency and driver envelope size.
In the case of employing TRIZ: you might avoid some of the tradeoffs altogether. If the woofer is not made to go through high low-frequency excursions because of its smooth transition to direct radiating mode--via the use of (integral) subwoofers below perhaps 80-100 Hz, then you've separated the issues causing IMD. IF you can make this frequency-based hand off below the listening room's Schroeder frequency, then you've significantly mitigated the effects of in-room loudspeaker lobing (although separate LF driver ear-room localization issues are still issues until you get below ~50-80 Hz).
Chris
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Great feedback guys!
I'd have to study the design to see if its something I might be able to do correctly and efficiently. Slot loaded woofer, gotcha.
You guy talk about the k-402 as if someone is actually selling them lol.
I found these
https://www.ebay.com/i/132991827153?chn=ps
Vintage Community FIBERGLASS Bi-Radial Horns 2” Throat 4 Bolt 34x10x21 | eBay
Wish I new the formula to figure out the limits of frequency dispersion vs size, as well as limits of loading frequencies.
On a positive note I am finding some capable 18" drivers.
I'm also confused whether or not the radian 950 is flat enough, in response, or if I'd want to get a bms4590 with passive crossover just to create a equalization starting point for voicing and room correction via dsp.
The search continues, I'm headed to the stereo shop to see what they have to audition.
This any good?
Original EAW Constant Directivity Fiberglass Horn Lens w/ 2" Throat (No Driver) | eBay
Probably not....
I'd have to study the design to see if its something I might be able to do correctly and efficiently. Slot loaded woofer, gotcha.
You guy talk about the k-402 as if someone is actually selling them lol.
I found these
https://www.ebay.com/i/132991827153?chn=ps
Vintage Community FIBERGLASS Bi-Radial Horns 2” Throat 4 Bolt 34x10x21 | eBay
Wish I new the formula to figure out the limits of frequency dispersion vs size, as well as limits of loading frequencies.
On a positive note I am finding some capable 18" drivers.
I'm also confused whether or not the radian 950 is flat enough, in response, or if I'd want to get a bms4590 with passive crossover just to create a equalization starting point for voicing and room correction via dsp.
The search continues, I'm headed to the stereo shop to see what they have to audition.
This any good?
Original EAW Constant Directivity Fiberglass Horn Lens w/ 2" Throat (No Driver) | eBay
Probably not....
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This white paper by Tom Danley gives the formula:
https://www.google.com/url?sa=t&sou...FjAAegQIBBAB&usg=AOvVaw1Psf1pwQc_xW3uhMHb3fA6
Although you will find that the formula doesn't predict the dispersion limits shown by Chris's design. That disign maintains directivity much lower than the formula predicts. I'm not sure why that is. I'm sure Chris will chime in.
https://www.google.com/url?sa=t&sou...FjAAegQIBBAB&usg=AOvVaw1Psf1pwQc_xW3uhMHb3fA6
Although you will find that the formula doesn't predict the dispersion limits shown by Chris's design. That disign maintains directivity much lower than the formula predicts. I'm not sure why that is. I'm sure Chris will chime in.
It's half wavelength on mouth size (each direction of horizontal or vertical) for directivity loss--without boundary gain effect helping to delay loss of directivity.
It's quarter wavelength on horn length, except when the loudspeaker is in boundary gain. See figures 4-6 in the following Bruce Edgar article on tractrix horn profiles for the low frequency extension effects of boundary gain (which is amazing--especially for DIY): http://www.diale.org/pdf/The%20Tratrix%20Horn%20Contour.pdf
Boundary gain makes all the difference in the world. I would go so far as to say that anyone that is not considering it in their design is basically throwing away 90% of bass horn design trades (and a bit disconcerting to see how many still fail to use it).
The effect of elevated mid-wall (half space) + floor boundary gain (quarter space) helps to produce the K-402-MEH EQed frequency response posted. If you put that design in the room corner on the floor, it picks up over 12 dB of boundary gain at 40 Hz, free of charge--something that should get anyone's attention. Learning how to use that gain without compromising midrange imaging is key. See Corner Horn Imaging FAQ
Like I said above, the horn doesn't have to be in corner (8th space) in order to pick up boundary gain. Sometimes half-space is sufficient to change the game design-wise, if the horn is especially suited to picking up that gain (as big-mouth horns do--like the K-402).
Chris
It's quarter wavelength on horn length, except when the loudspeaker is in boundary gain. See figures 4-6 in the following Bruce Edgar article on tractrix horn profiles for the low frequency extension effects of boundary gain (which is amazing--especially for DIY): http://www.diale.org/pdf/The%20Tratrix%20Horn%20Contour.pdf
Boundary gain makes all the difference in the world. I would go so far as to say that anyone that is not considering it in their design is basically throwing away 90% of bass horn design trades (and a bit disconcerting to see how many still fail to use it).
The effect of elevated mid-wall (half space) + floor boundary gain (quarter space) helps to produce the K-402-MEH EQed frequency response posted. If you put that design in the room corner on the floor, it picks up over 12 dB of boundary gain at 40 Hz, free of charge--something that should get anyone's attention. Learning how to use that gain without compromising midrange imaging is key. See Corner Horn Imaging FAQ
Like I said above, the horn doesn't have to be in corner (8th space) in order to pick up boundary gain. Sometimes half-space is sufficient to change the game design-wise, if the horn is especially suited to picking up that gain (as big-mouth horns do--like the K-402).
Chris
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Hi AllenB
I am glad you do not take any offense. I am genuinely interested in this topic, because I have heard many different Unity/Synergy implementations, and do not detect the alleged problem. This, of course, does not mean that the problem does not exist, hence my, unsuccessful quest for some objective data.
Kindest regards,
M
I am glad you do not take any offense. I am genuinely interested in this topic, because I have heard many different Unity/Synergy implementations, and do not detect the alleged problem. This, of course, does not mean that the problem does not exist, hence my, unsuccessful quest for some objective data.
Kindest regards,
M
I guess a start would be to read the REW function description:
Spectrogram Graph
I find graphs like these useful for analyzing what I get at my specific listening spot. (among other representations of the IR)
I was at least one of the people that nagged John (creator of REW) to offer the type of wavelet presentation, concentrated on showing the timing to REW.Here's a piece of history of how we got the currently available type of wavelets.
It is one of the visual interpretations of what happens over time at each frequency. It's the same data as available in the IR, just presented different.
For instance the reflections show up as parallel lines to the main signal in a high resolution. Easier to "see" what happens to the wavefront over time. It also presents us with a clear picture of the "hand-over" from one driver to the next as seen in time (the effects crossovers have as seen in time). This way it can be a great visual helper/tool to get your crossover dialed in just right.
A comparison of (16) different horns with spectrograms shown, as well as a description of what you can see in them can be found here:
http://unepassionaudiophile.fr/wp-content/uploads/2018/01/Horns_measurements_ETF2010d-1.pdf
(thanks to JMLC, may he rest in peace)
Hope that helps.
I've been running mine down to about 350Hz for a decade with no issues, with an AE TD15S above and below. Active of course. Downside? What downside? Good engineering is selecting the right balance of the compromises, and if the ports are mucking something up, I simply don't hear it, and therefore don't care.
As they're getting rebuilt to make them pretty, I'm dabbling with the idea of replacing the 15's with an Edgar Show horn. There'll still be the FTW subs under them.
Hi Brett,
Since we had already moved from the original topic, apology to OP, I had the Show horn. They wer crossed over at about 350-400Hz, and in my small room, positioned in the corners and raised about 4 inches from the floor per Bruce's recommendation, I did not find a need for a sub-woofer.
As my DS-1428s are coming back, I think that I will reclaim them form my friend. So, thank you for the reminder.
Kindest regards,
M
Since we had already moved from the original topic, apology to OP, I had the Show horn. They wer crossed over at about 350-400Hz, and in my small room, positioned in the corners and raised about 4 inches from the floor per Bruce's recommendation, I did not find a need for a sub-woofer.
As my DS-1428s are coming back, I think that I will reclaim them form my friend. So, thank you for the reminder.
Kindest regards,
M
Or this?
Does 600Hz easily with the HF950 Horn and I bet it'll take 400Hz with a K402 or similar sized horn.
Raw reponse on a custom 60x40 horn about the size of a XT1464 (No EQ, no HPF):
An externally hosted image should be here but it was not working when we last tested it.
Does 600Hz easily with the HF950 Horn and I bet it'll take 400Hz with a K402 or similar sized horn.
Raw reponse on a custom 60x40 horn about the size of a XT1464 (No EQ, no HPF):
Attachments
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Faitals are nice, but the RCF is one of the very few 4" diaphragm drivers capable of high output levels in PA cabs, crossed below 700Hz. It also does 20kHz without a severe drop in the top octave, or major breakup.
In Europe it's quite a bargain, but I am not sure about availability in the US.
@camplo: evidently I appreciate a proper 808 beat, like this, as well.
In Europe it's quite a bargain, but I am not sure about availability in the US.
@camplo: evidently I appreciate a proper 808 beat, like this, as well.
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