Yes, here are my basic goals, which I hope aren’t unrealistic given my 2660 cu ft room, to what extent I could acoustically treat it and how well it could accommodate two pairs of speakers of opposite directivity:
Higher Directivity/Deeper than Wider Soundstage Speakers (Crowe ES450/B&C DCM50 or SB Audience 65CDNT + Fostex Bullet Tweeter/Crowe Wavguide combos): “They are Here” presentation for late night listening (yes!) and with paper/polyester (DCM50) or titanium (65CDNT) diaphragms to better accommodate (??) lower to good quality recordings. Also, given their narrower horizontal dispersion, that in the absence of a center channel speaker compatible with the main speakers, I’m hoping they may suffice to present movie dialogue from DVDs and BDs. Unless you think I’d be better off with a pair of these https://www.crutchfield.com/p_265F226BK/Revel-PerformaBe-F226Be-Black-Gloss.html and this center speaker. https://www.crutchfield.com/p_265C426BEW/Revel-C426Be-Walnut.html OR the aluminum rather than beryllium.
Lower Directivity/Wider than Deeper Soundstage Speakers (290 or 4001 horn/RadianBe combo): “You are There” presentation for movie soundtracks, orchestral and other music recorded in large live rooms- and where beryllium diaphragms will extract detail from very good to excellent quality recordings.
Pierre reviewed 50 of my uncompressed WAV files of CD track rips and a Youtube of what I believe was a quality recording of live concert, which he accessed by downloading a zip file from my google drive. And Pierre entered his evaluations into the Excel file I had included. While Pierre’s 4001/Radian 745Be combo/TAD 1601B woofer found many of my recordings quite compressed (even from major record labels) and/or with some occasional distortion on the peaks, the better CD track rips blew him away. And even though he's 11 ft from the speakers, and which are only 2.5 ft from the rear wall, Pierre noted that three of my recordings gave a deep as well as wide sound stage.
And when an album is available, I will instead opt for the 24-bit download.
https://www.hdtracks.com/?gclid=Cj0...aAlXMEALw_wcB#/album/609d371c6e312b499e6498bb
But true or false: Would the 4” version of the RadianBe cross much better than the 3” with the 500Hz Fc of the Altec 416 woofers in 3 cu ft sealed cabinets?
And might there be any less woofer beaming and better midrange presentation with the 4” Radian?
However, if I used the 3 cu ft sealed Altecs with the ES450 horn and built, (Lynn Olson’s) 4.2 cu ft sealed cabinets for the 290/4001 horn, would there be any advantage to choosing the 3” Radians? See attached datasheet.
Have four subs https://www.rythmikaudio.com/F12.html
But how problematic is it to provide the opposing (?) acoustical requirements for these different speakers in the same 2660 cu ft (mostly empty) room?
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Pierre's observations with both high and low directivity speakers:
https://www.diyaudio.com/community/threads/beyond-the-ariel.100392/page-764
JMLC (AH425): One hears very little room reflections when listening inside the sweet spot "cone". It feels a little like wearing headphones, but with all the benefits of a whole body experience (feeling bass, etc). In a typical sized room the sweet spot is wide enough for one or two listeners, but beyond that the tonality starts degrading. One should be aware of this if intending to position listener off axis (e.g. near side or front walls) . The ceiling reflection can add some "height" to the stereo image, which can sound pleasant on some recordings (pipe organ) but otherwise smears details. The JMLC horn sounds even better in my brother's large room than in my own which is of typical size but has a low (7 foot) ceiling. Still, while I use the TH4001 I miss the JMLC experience.
Sectoral (TH4001, A290) : These horns with vanes provide horizontal dispersion wider than is typically needed in a home setting. In practice side wall reflections are alleviated by toeing-in the speakers and haven't bothered me. The sweet spot is very large (width and depth) and the speakers can be listened to closer and further off axis than the JMLC, without noticeable tone degradation. By virtue of its low profile, the sectoral horn allows positioning the two drivers closer together. At short to moderate listening distances one can hear this as tightening the image. A benefit in my room is that the narrow vertical dispersion attenuates ceiling reflection.
https://www.diyaudio.com/community/threads/beyond-the-ariel.100392/page-764
JMLC (AH425): One hears very little room reflections when listening inside the sweet spot "cone". It feels a little like wearing headphones, but with all the benefits of a whole body experience (feeling bass, etc). In a typical sized room the sweet spot is wide enough for one or two listeners, but beyond that the tonality starts degrading. One should be aware of this if intending to position listener off axis (e.g. near side or front walls) . The ceiling reflection can add some "height" to the stereo image, which can sound pleasant on some recordings (pipe organ) but otherwise smears details. The JMLC horn sounds even better in my brother's large room than in my own which is of typical size but has a low (7 foot) ceiling. Still, while I use the TH4001 I miss the JMLC experience.
Sectoral (TH4001, A290) : These horns with vanes provide horizontal dispersion wider than is typically needed in a home setting. In practice side wall reflections are alleviated by toeing-in the speakers and haven't bothered me. The sweet spot is very large (width and depth) and the speakers can be listened to closer and further off axis than the JMLC, without noticeable tone degradation. By virtue of its low profile, the sectoral horn allows positioning the two drivers closer together. At short to moderate listening distances one can hear this as tightening the image. A benefit in my room is that the narrow vertical dispersion attenuates ceiling reflection.
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This was why I asked Camplo if the 4” RadianBe would cross much better than the 3” with the 500Hz Fc of the Altec 416 woofers in 3 cu ft sealed cabinets?
And might there be any less woofer beaming and better midrange presentation with the 4” Radian in the A290 horn-and in my mostly empty (save for the subs and one small upholstered chair) 2660 cu ft room? But any other 4" vs. 3" RadianBe/A290 tradeoffs?
My living room has thin (!) wall to wall carpeting, but much of it is covered with 3/4" Karastan remnants. Will that do the trick? But when you say "hanging" diffusers/absorbers from the ceiling can this be done without tearing off paint layers or leaving noticeable marks on my white triangular ceiling? White gaffers tape??
So far, my only tube creature is the Don Sachs preamp. http://www.dsachsconsulting.com/custom line stage.html I got it to drive my First Watt F4 power amp. https://www.firstwatt.com/product/f4/
I also have the First Watt J2. https://www.firstwatt.com/product/j2/ My concern with this amp is that according to John Atkinson's measurements the J2 will sound great so long as system impedance is doesn't drop anywhere near 4 ohms. So, while the Altec 416s are 8 ohms at least I can choose 16 ohm Radians.
My concern is that while the the J2 uses feedback the F4 doesn't. https://www.firstwatt.com/products/ And though my Rythmik subs will take over for the Altecs somewhere between 100Hz and 70Hz, and I wouldn't expect to play the Altecs above ~ 90db at 100Hz, if that much, seated 11 ft away, will my drivers as safe with the F4 as with the J2?
Are you sure that you don't mean that the A290 gives a "You are There" rather than a "They are Here" event presentation? From experience, Pierre and Gary Dahl said that the latter is what the JMLC does; the A290 and TH4001 gives the "Your are There", or as Camplo calls it, direct sound.
If you are having touble with adapters check out this thread, where Pierre perfected his T3 adapters for his RadianBe/4001 combo. He told me that his adapters makes his speakers disappear! https://www.diyaudio.com/community/threads/jmlc-and-yuichi-horns-measurements.395046/page-2
A woofer's Fc is it's resonant frequency in a sealed enclosure, always higher than it's Fs (free air resonance).
The Fc of the Altec 416 woofers in 3 cu ft sealed cabinets would be ~60 Hz.
A horn's Fc is it's frequency of cut off, typically a crossover ~an octave above Fc is chosen.
Compression drivers don't have an Fc, but in general a larger diaphragm can be crossed lower, due to having more displacement capability.
You may be interested in matching the beamwidth of whatever horn you choose with the woofer's beamwidth.
The Altec 416 woofer's beamwidth probably is similar to this EV 15" :
At 800Hz, it's -6dB point is wider than 90 degrees, at 1500Hz, over 60 degrees.
At 500Hz, the Altec 416 probably is ~100degrees. It wouldn't be considered "beamy" by most even as high as 1000Hz.
I'll have to read through the quotes tomorrow. There's some interesting developments with the PRV drivers I'm taking a closer look at. They look very promising, even overlooking their cheap price. The drivers play down to 450 hz which is excellent for a 3" diaphragm. The top end easily extends up to 14 khz without excessive breakup of the Ti hybrid diaphragm. I’ve already listened to the driver on a 400 hz expo horn and so far I'm very impressed. It shames me to say it sounds better in some regards than other ferrite 2" drivers, even ones costing over twice the price, which is highly impressive for a $120 driver. This includes the $40 replacement hybrid diaphragm . Part number for the driver is D3220PH and the Ti diaphragm number is RPD3220TIH-ND. The original phenolic diaphragm is also very good but predictably won't play higher than 8k. There's also a neo version of this driver which I haven't tested yet. You can't buy the compact ferrite version with the Ti diaphragm. It has to be purchased separately. The back chambers will require a layer of wool felt to dampen as they don't come with any dampening from the manufacturer. Its definitely needed if you want cleaner treble from the Ti diaphragm.
I have to get measurements on the A290 for comparison sake of diaphragms and throat adapters.
I have to get measurements on the A290 for comparison sake of diaphragms and throat adapters.
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Make sure compression driver exit angle matches horn requirements. The Radian 950PB performed poorly on the A-290, huge dip right around 1kHz.
The TD-4001 has an exit angle around 8 - 10 degrees vs 22 or so for the 950.
The Radian 950 was not a good match for this and other reasons. There are a couple of jbl drivers 2451 ? when used with Be diaphragm are reportedly good.
2441 sounded better imo than Radian 950
The TD-4001 has an exit angle around 8 - 10 degrees vs 22 or so for the 950.
The Radian 950 was not a good match for this and other reasons. There are a couple of jbl drivers 2451 ? when used with Be diaphragm are reportedly good.
2441 sounded better imo than Radian 950
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You are there = you are dominated by direct sound, the stereo signal has its own reverb and the direct sound dominant signal brings a strong perception of being in a different acoustical environment than your living room
They are here = you are dominated by indirect sound, thus, the reverb of your room is now the dominant reverb characteristic of the listening experience. The source will now sound as if it is in your room, meaning, however your room sounds, reverb wise, the source will be as if its performing in your room, as in literally, like they are standing in your room and the reverb of your room is what you will mainly hear though the reverb of the mix could "sweeten" things.
So one situation you might sound like the band is performing in an acoustical space as intended by the engineer who designed the signal.... in the other the reverb will resemble your room so it will sound like they have set up, in your living room.
Both have a different take on realism but the "You are there" is the more accurate reproduction, technically speaking
The "They are here" approach will lean towards more of your content to as if its in the same acoustical environment, because it is, your room that is... "You are there" will cause things to sound as diverse, reverberation wise, as the different recordings you listen to
They are here = you are dominated by indirect sound, thus, the reverb of your room is now the dominant reverb characteristic of the listening experience. The source will now sound as if it is in your room, meaning, however your room sounds, reverb wise, the source will be as if its performing in your room, as in literally, like they are standing in your room and the reverb of your room is what you will mainly hear though the reverb of the mix could "sweeten" things.
So one situation you might sound like the band is performing in an acoustical space as intended by the engineer who designed the signal.... in the other the reverb will resemble your room so it will sound like they have set up, in your living room.
Both have a different take on realism but the "You are there" is the more accurate reproduction, technically speaking
The "They are here" approach will lean towards more of your content to as if its in the same acoustical environment, because it is, your room that is... "You are there" will cause things to sound as diverse, reverberation wise, as the different recordings you listen to
Sorry, my igorance. I thought Fc was crossover frequency. I did find this, though I can't assimilate enough of the info here to attempt to usefully answer my questions. http://alteclansingunofficial.nlenet.net/publications/techletters/TL_237.pdf
But Pierre said that given his TH4001, that (his TAD 1601B) woofer beaming is mostly due to the diameter differences in his 3" RadianBe driver and the 15 woofer. Thus would a 4" RadianBe result in substantially less woofer beaming?
Thanks for this warning!! Now if only I could find out how well the 950Be would work with the TH4001 with the right adapter. Maybe Chalshus, post 4284?
https://www.diyaudio.com/community/threads/ultimate-open-baffle-gallery.123512/page-215
The Radian 950PB whether Be or aluminum diaphragm would be a huge mistake. The only drivers IMO that will provide good performance on this horn are TAD TD-4001 or JBL 2441, the JBL 2451 with Be replacement diaphragm is reputed to be good, but I have no direct experience. The driver geometry of the Radian 950PB is INCOMPATIBLE with the Yuichi A-290. The smaller Radians with adapters apparently work OK.
I would take this to be true with the TH-4001 as well since it was designed for use with the same class of driver.
Also can you give room dimensions in sqft and provide, height, width depth as well as other oddities like cathedral ceilings and openings large or small and any large expanses of glass.
TBH I would do a complete reset and look for horn with a 1 inch to 1.5 inch throat. You will likely be a lot happier unless you really need to go low. (You don't despite the comments)I think a smaller mid-bass crossed at 800 - 900Hz with a sub or two is going to give you better results.
The Yuichi and large format drivers is a the realization of a stupid dream that I am still trying to recover from. Back when I made the switch from 1 inch drivers and lensed JBL horns for same there was a large perceptible drop in overall sound quality. A decade later I am achieving about the same flatness as I did in room with that set up with a huge expenditure in time, labor and money, since no direct comparison is possible I do not even know if the system sounds as good as it did before that fateful day.
I would take this to be true with the TH-4001 as well since it was designed for use with the same class of driver.
Also can you give room dimensions in sqft and provide, height, width depth as well as other oddities like cathedral ceilings and openings large or small and any large expanses of glass.
TBH I would do a complete reset and look for horn with a 1 inch to 1.5 inch throat. You will likely be a lot happier unless you really need to go low. (You don't despite the comments)I think a smaller mid-bass crossed at 800 - 900Hz with a sub or two is going to give you better results.
The Yuichi and large format drivers is a the realization of a stupid dream that I am still trying to recover from. Back when I made the switch from 1 inch drivers and lensed JBL horns for same there was a large perceptible drop in overall sound quality. A decade later I am achieving about the same flatness as I did in room with that set up with a huge expenditure in time, labor and money, since no direct comparison is possible I do not even know if the system sounds as good as it did before that fateful day.
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This is why I have attitude, trying to help you avoid a serious mistake. 😀 Look at that notch at 1kHz, that all relates to driver geometry at the throat. I will look for the others. I would say truthfully in my case that the purchase of the 950PB was an expensive misstep, and I have not been able to sell them so far. Even with sophisticated DSP I was not able to fix this and get it to sound good. There are STRONG hints of this behavior in the published curves for this driver on other horns. The 950PB actually worked quite well on the JBL 2380A horn, but that was from a time when I was even less sophisticated in understanding than I am now. (I recall the dip was there on the 2380A but less pronounced.)
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2dB per major division, 1/6th octave smoothing, Yuichi A-290 horn, 200 - 22kHz. What I refer to as a 2441 is actually a 2440 with 2441 diaphragms, I am not aware of differences in the phase plugs of the two drivers, but that doesn't mean there isn't a difference. The Tad/Yuichi combo would fall within +/-2dB from 600Hz - 7kHz in this measurement.
Please note these are very early, and I have improved the flanges and other things since that time so there might be a small improvement
Regardless, the Radian is much, much worse, and I doubt the Be diaphragm is going to fix this problem which I think is tied to exit angle and path length.
Please note these are very early, and I have improved the flanges and other things since that time so there might be a small improvement
Regardless, the Radian is much, much worse, and I doubt the Be diaphragm is going to fix this problem which I think is tied to exit angle and path length.
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You would need to look at the manufacturer data sheet, but as I recall it just from center axis to either side. And it is not always given. The key is to use drivers that match the exit geometry of the TAD or JBL drivers (they were designed by the same guy - Bart Locanthi.) The 4001 physically is almost indistinguishable from my JBL 2440/2441.
Shall be 10 degrees for the TD-4001, 10 degrees for the TD-4002 at 39mm or 2".
While 8,5 for the TD-4003.
You forgot the obvious JBL 2450H, use with a SL or Materion Be diaphragm depending on budget, and preference.
Has the same throat dimensions and angle as the TD-4001.
While the 2441 has a 8 degree throat angle that is different from the TD-4001.
Nothing wrong with the 2450SL or 2451 1,5"s either, but the 2450H is the natural choice if not a TD-4001.
The driver does not present a radial wavefront, yet that's what some of these horns are suited to. Producing one well is not a simple task. Stories about the historical reasoning used are difficult to find, and I'd assume some trial and error was used to discover a reasonable compromise.
