Am now arranging an audition for one horn system next week and two others for next month.
Dropping a spoon on a china plate will result in a transient over 115dB, don't worry about turn off/on transients damaging your hearing, unless you plan to do it repeatedly on an hourly basis.
If you are the forgetful type, sequencers are helpful to avoid annoying noises.
If you are worried about power line transients, plug your equipment into a reputable uninterruptible power supply (UPS).
Power supplies don't have anything to do with limiting or adjusting average SPL.
Digital signal processing with separate peak and RMS limiters on each output section could squash music or noise dynamics to whatever threshold you want to set for each.
There are as many (or more) choices (and opinions) for implementation of compressor/limiters than there are for compression drivers.
If you want something more easy to implement, you might consider this:
https://www.tcelectronic.com/product.html?modelCode=0815-ABX
Using it's optional hardware controller (and a dB meter..) you could "dial things in" at your 11 foot position.
TC Electronics has been making great sounding gear since the 1970s.
I have no personal experience with the Brickwall HD Master Limiter, but never have been disappointed with any TC gear I've used or owned in that time.
Art
https://www.tcelectronic.com/product.html?modelCode=0815-ABX
Music file playbacks usually with JRiver, so my pc feeds audio via USB to my DAC. So connect this limiter to another of the pc's USB ports and JRiver can access it as a plug-in?
That's just crazy. Fitting a limiter to thwart dynamic peaks on a horn system.
For goodness' sake: just build a cone & dome box and be done with it, then!
Incidentally: it's sustained high SPL that damages hearing, not instantaneous sub-millisecond peaks.
For goodness' sake: just build a cone & dome box and be done with it, then!
Incidentally: it's sustained high SPL that damages hearing, not instantaneous sub-millisecond peaks.
I don't know what "JRiver" or "DAC" you use, or how to operate them.
The TC user manual might have the answer to your questions:
https://mediadl.musictribe.com/down...ronic/BRICKWALLHD-DT/BRICKWALL HD-DT_M_EN.pdf
From what it says here:
https://wiki.jriver.com/index.php/Parametric_Equalizer
In addition to all the PEQ functions, Jriver already has various types of limiting, so seems there would be little need for another plug in, unless you want the convenience of the TC's remote controller, or you prefer it's algorithms.
Anyway, learn to use what you have before looking for more stuff.
One that struck me hearing this horn https://josephcrowe.com/products/3d-cad-files-horn-no-1994-es450-biradial-for-jbl-2446-2-throat is that it apparently has very good vertical off axis response-presumably much unlike the TH4001. One thing that rather struck me was that after we had removed the Fostex tweeters from atop the horn I then slowly raised my body/head with eyes perpendicular to the horn until I was standing, then slowly re-seated myself. I did this a few times but could detect no loss in top upper midrange of the ES450/DCM50 combo. I guess such a test would have proved more telling of the ES450 horn's vertical off axis response if what I heard yesterday was a two-way system.
Yesterday afternoon it was almost two hours with these.
https://josephcrowe.com/products/speaker-system-no-2095
"Top upper midrange" could mean anything below the tweeter crossover range, whatever that was.
Depending on the height of the horn, room reflectivity, and the spectral content of what you happened to be listening to when you stood up, detecting a change may be difficult regardless of the horn's directivity pattern.
Using pink noise as signal makes it far easier to hear polar patterns than most music.
Right, the DCM50 midrange driver's native on axis response dies above 8kHz, unless using a high frequency driver, you haven't heard what the ES450 top octave sounds like.
The Fostex T925A and T90 "bullet tweeters" have similar narrowing vertical beamwidth at higher frequencies akin to the ES450 (or TH4001, or AH425), so you can expect similar effects listening to those types of horns driven with high frequency drivers, other than the comb filtering from separate mid/high sources.
Art
Glad to see that toeing in apparently does reduce that on-axis midrange forwardness.
But do you ever experience what Pierre found did with his Radian 745Be/AH425 combo above TAD 1601B woofers?
Post 236. https://www.diyaudio.com/community/...orns-measurements.395046/page-12#post-7350302
Soundstage
Commenting briefly on the TH4001 horn, I appreciate how it positions the drivers closer together than the round AH425, and as a result, how musical instruments sound better integrated, e.g. notes don't appear to climb up or down in space according to their frequency. Tonality remains acceptable even if I move my head somewhat close to the speakers' plane (a hard test). The image shifts left or right within the sweet spot (unavoidable), yet the tonality remains mostly unchanged. The fins of the TH4001 rule here, and the adapters don't seem to make much difference.
The TH4001 horn is 9" tall, the AH425 is 16.53" (420mm) tall.
The center to center distance between horn and woofer could be reduced by about 3.75" (the distance across the palm of my hand) using the TH4001 compared to the AH425, reducing the vertical "climbing distance".
That said, one could position the AH425 to overlap the woofer cabinet, reducing the "climbing distance" to less than that of the TH4001.
Some do that, others mount the AH425 "flying high" above the woofer.
Apparently, those do so for aesthetics while paying the penalty of less integrated (less coherent) sound.
Lucky for me I asked about this at this very late date!!
So, then use gaffers tape to secure (?) the horn/driver combo to the cabinets?
But what, if any, are the downsides of placing the edge of the 425 horn just above the woofer surrounds?
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I have no reason to doubt that, though long time 425 user IronmanIV did say While the Le Cleach horns are quite nice in many ways, I do think they are a little hot in the midrange on axis and Jean Michel's recommendation appears to make a big improvement.
And fortunately 425 user Bryan S emphatically agrees; post 15396.
Also, might the AH425’s high directivity pattern also be why the Yamaha JA6681B’s 107db appear to be safer for my ears to use in such a beamy horn https://audio-database.com/YAMAHA/unit/ja-6681.html than 17db higher Radian 745Be? https://www.usspeaker.com/radian 745neoBepb-1.htm
However, what remains true with the Yamahas is that while using them might reduce my chances of accidental hearing damage, however unlikely (??), our team has yet to design a replacement diaphragm and contract with an OEM for group buys. https://www.diyaudio.com/community/...ompression-driver.163469/page-31#post-7680257
You and/or Arez also mentioned that diaphragm’s beryllium suspension will or has suffered microfractures over time, although g3Dahl apparently continues to enjoy his Yamaha/AH425 combo for the last seven years.
In any case, as the Yamaha’s HF response falls quicky above 10kHz, I thought of alternatives like
https://www.sbaudience.com/index.php/products/compression-drivers/rosso-65cdn-t/ But given the Yamaha’s
small but enduring celebrity how likely would the 65cdnt sound as nice?
That said, I’m of course not comfortable pursuing use of a driver for which there are no replacement diaphragms, and yet I want to realize what Gary, Pierre and others have enjoyed from the Yamahas.
If so, then the only other matter would be a tweeter or not for the Yamahas. Regarding the photo of Gary’s speakers in post 672, you observed the position of the Raal ribbon tweeters.
You also wondered on how the tweeter would perform depending on whether the back of the horn was in what way acoustically treated. What type of recommended acoustical treatment and how to affix to the back of the horn?
But assuming minimal distance between the 425 horn’s edge and the midwoofer is best, as per posts 15689-90
https://www.diyaudio.com/community/threads/beyond-the-ariel.100392/page-785#post-79775 , what tweeter(s),
price aside, might you suggest? And how above or to what side of the left and right horn should the tweeters be placed?
As for the 745Be, might not it be safer for my ears-and perhaps even to perform more impressively-if it were used in a CD horn, as more of its energy gets more evenly dispersed in the room?
But recall that while not a CD horn you recently asked if I might want to use that driver in the TH-4001 horn. While Docali designed the throat adapters which Pierre then finished tweaking and built for that horn/driver combo, Docali and Marco advised me against using throat adapters in any case. Thus, as per their advice that rules out the TH4001/745Be combo.
So, if I do the AH425/Yamaha or EV or ? driver combo then if not another essentially beamy exponential horn https://josephcrowe.com/products/3d-cad-plans-for-es-290-biradial-horn-horn-no-1670 , which particular
JBL https://jblpro.com/en-US/innovation-directivity
https://audio-database.com/JBL/unit/2365.html
B&C
https://www.bcspeakers.com/en/print/horn/1-0/0/me90
or NicoB
https://audiohorn.net/x-shape-horn/
https://audiohorn.net/next-gen-bi-radial-horn/
1.4” CD horn/Radian 745Be combo might best integrate with my Altec midwoofers?
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Same advice you need to hear them and make a decision. With the JBL's of the waveguides available you would have a choice or 2" 1.5" and 1". You would need an adaptor for the 1.5" or 2" and no idea where you would find one that didn't potentially effect the performance. They are also different families the 2365 being 1st gen Biradial so dated. The elephant in the room is what pattern? 100x100 60x30 90x60? They all going to be different in room. And all with sound different in your room. It's almost impossible to make recommendations without some kind of preference used as a reference point.
Do you have something like a Sam Goody or similar that sells smaller bridge mount monitors? You might be able to get a feel for differences by comparing different models with significantly different directivities. It's a tuff call if this would help you at all. Depending of how they are set-up and how flexible they would be to moving things around. If you can audition an M2 or 308Mk 2 wide 120x90 vs tighter pattern. Both JBL's very close pattern wise and sound remarkably similar when set-up side by side image wise.
Rob 🙂
I cannot remember where I said that. When the adapter is part of the horn design especially designed together with the horn using the same flare rate then I do not not any issue. If you have a rectangular shape and throat entry of the horn then there is no other way to use an adapter.
The sensitivity of a driver is dependent on the horn.
Midband sensitivity of Yamaha JA6681B, Radian 745Be, (and JBL, EV, B&C etc.) drivers all are within a few dB. Some drivers are purposely designed for flatter response, throwing away some midrange sensitivity.
Regardless of the horn/driver combination you choose, it will need to be level balanced to your woofer's sensitivity of about 98dB 1watt/one meter.
Your speakers will be about as loud with one watt as a bookshelf speaker would be with 10 watts, but there is no reason you need to listen to it 10dB louder.
The crossover frequency and slope can make a 10/1 difference in the excursion required from a high frequency driver.
The JA6681B's copper/Be suspension "fingers" could last indefinitely if not stressed by too much excursion.
Or they could be broken in one loud listening session with a 400Hz 6dB/octave crossover.
If equalized to the same response target, they would likely sound "as nice".
I didn't wonder how the tweeter would perform, I simply pointed out much of it's output would reflect off the back of the horn if it didn't have absorptive material on it.
Acoustic foam or felt could be cut to shape and glued on to the back of the horn with contact cement.
I wouldn't suggest using any tweeter over using a driver with good high frequency response like your Radian Neo 745Be on the AH425.
Each choice of tweeter position would be a compromise I would not choose to make.
The choice of horn will have no bearing on being safer for your ears.
I don't know whether you would be more impressed by even dispersion or a smoothly narrowing response.
I don't recall asking you that.
I do recall asking what dispersion pattern you prefer, which you were not able to answer.
The horn with the dispersion pattern you prefer would best integrate with your Altec midwoofers.
Since you don't know which pattern you prefer for your room, I'd suggest the horn the OP (Lynn Olson) chose and you already own, the AH425.
Art
You are right. It was Marco_gea who mostly advised against adapting the 745Be to the 4001 horn; post 228.
Instead, you replied to Marco that the 745NeoBe driver/TH4001 horn would be "quite a good match"; post # 217
https://www.diyaudio.com/community/...0-or-tad-th-4001-clones-makers.375215/page-11
And Arez agreed for the same reason; post # 218.
Pierre certainly seems pleased with results; post 15266.
However, as drawn to the 745Be/4001 combo, when I once thought otherwise, I think you replied that the 4001 is not a constant directivity horn. https://audiohorn.net/img/bi-radial/TAD-TH4001-polar.jpg
This may not be a reason for me to decline using it, though would also like knowing Weltersys's views on same.
Speaking of CD horns, Arnaud Le Gac replied that nearly all of his are 2". https://alg-audiodesign.com/pavillons/
So if I were to use any such recommended its adapter may have to be specifically designed to interface with the 745Be driver, which at this point is very unlikely to happen.
But I expect to hear both of NicoB's horns this month. https://audiohorn.net/x-shape-horn/
https://audiohorn.net/next-gen-bi-radial-horn/
And as you have previously discussed NicoB's designs and/or his measurements with him and others at some length here, I am very interested in any facts, thoughts and/or questions you may have about those two horns. And also how much you may think the 745Be would be a good driver to use with either horn.
Again, I expect to hear both of NicoB's CD horns this month. The X40, for a 15" woofer is 85 x 60 degrees. But is its recommended 700/750Hz crossover frequency range too low for the Radian745Be/Altec 416-8B?
https://audiohorn.net/x-shape-horn/
IIRC, Docali said that the TH4001 is not a CD horn, though NicoB claims this of his improved version of the TH4001.
https://audiohorn.net/next-gen-bi-radial-horn/ It has 90 degrees hor dispersion.
The 1.4" Faital HF1440 Nicolas recommends crosses at 750 Hz.
Like Arnaud, Nicolas doesn't like Radian drivers; "Be diaphragms are embossed. Phase plugs are outdated".
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What else could be called constant directivity control when not the TH4001?You are right. It was Marco_gea who mostly advised against adapting the 745Be to the 4001 horn; post 228.
Instead, you replied to Marco that the 745NeoBe driver/TH4001 horn would be "quite a good match"; post # 217
https://www.diyaudio.com/community/...0-or-tad-th-4001-clones-makers.375215/page-11
And Arez agreed for the same reason; post # 218.
Pierre certainly seems pleased with results; post 15266.
However, as drawn to the 745Be/4001 combo, when I once thought otherwise, I think you replied that the 4001 is not a constant directivity horn. https://audiohorn.net/img/bi-radial/TAD-TH4001-polar.jpg
This may not be a reason for me to decline using it, though would also like knowing Weltersys's views on same.
Speaking of CD horns, Arnaud Le Gac replied that nearly all of his are 2". https://alg-audiodesign.com/pavillons/
So if I were to use any such recommended its adapter may have to be specifically designed to interface with the 745Be driver, which at this point is very unlikely to happen.
But I expect to hear both of NicoB's horns this month. https://audiohorn.net/x-shape-horn/
https://audiohorn.net/next-gen-bi-radial-horn/
And as you have previously discussed NicoB's designs and/or his measurements with him and others at some length here, I am very interested in any facts, thoughts and/or questions you may have about those two horns. And also how much you may think the 745Be would be a good driver to use with either horn.
I
You should know that there are a bunch of people here awaiting your detailed listening report. 😍
Really?? I was sure that you said the 4001 was not a CD horn; but can't find thread now. However, just by looking at the polar it's obviously that it's not directivity is not narrowing. https://audiohorn.net/img/bi-radial/TAD-TH4001-polar.jpg
But check out Bjorn's post 898 and my reply 899.
https://www.audiosciencereview.com/...peakers-is-it-me-or.9633/page-45#post-2274682
How might the diffraction horn he prefers work better than the 4001 horn to achieve spaciousness in a ~ 23 ft x 15 room and while maybe also having less other acoustical problems?
No doubt, but if possible can you or others quickly do better than the attached for defining important performance parameters for the listening sessions, each rated # out of /10 ?