In principle, you are right of course.
But in practice, with some speakers (e.g., omnis) that critical distance is so short that you always end up sitting farther away and hence only have the "they are here" effect.
Conversely, with most horns in typical rooms, the critical distance is long enough to enable experiencing the "you are there" effect while sitting at a normal reasonable distance from the speakers.
Exactly, practical positioning is very important for most people, especially those who have no dedicated listening room.
Often it's also about aesthetics and money, many have no possibility to have big speakers.
Key here is to realize the sound is likely still available regardless, and reachable without investment, just take a chair closer to speakers when ever there is time for good listen. This sound is not in the gear but in the positioning, inside you, in the auditory system.
Having done it for a while I've learned some records sound better with either, and some with the other and good chunk just fine with both. Also mood wants either, sometimes I wanna listen close and I take a chair, and sometimes I'm on the sofa. For example doing remote work it's better to listen further away so attention is not drawn to the music so much. I think it's good to have two good listening spots, one for each sound.
Often it's also about aesthetics and money, many have no possibility to have big speakers.
Key here is to realize the sound is likely still available regardless, and reachable without investment, just take a chair closer to speakers when ever there is time for good listen. This sound is not in the gear but in the positioning, inside you, in the auditory system.
Having done it for a while I've learned some records sound better with either, and some with the other and good chunk just fine with both. Also mood wants either, sometimes I wanna listen close and I take a chair, and sometimes I'm on the sofa. For example doing remote work it's better to listen further away so attention is not drawn to the music so much. I think it's good to have two good listening spots, one for each sound.
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That is, a radial like the ES450 rather than, say, the JMLC 425? Perhaps the latter horn might tend to excite room resonances less? But would not the ES450, ES290 or (especially with the right driver and adapter??) the https://audiohorn.net/next-gen-bi-radial-horn/ more likely deliver the You are Thereness sound I'm looking for?
I'm likely more ignorant of numerous acoustical phenonmena and how to measure and manage their impact on system sound than being truly too stupid to learn. So, if you Marco, Docali and others can at least help me settle on a horn/driver combo-given my goals and room environment as described-treating the room will happen later.
Worst case, companies like this give free consultations and provide Windows based test kits for in-home analysis for dummies. https://www.gikacoustics.com/?srsltid=AfmBOoqnWO-Q_kp0ydyxut6RdLZZ2ERnIk_GZlxDh-QMC5N2s5y0qQmt
Okay, I'll take your word for this. But in MY room (see post 219)-and perhaps after spending ~ $3.5K to treat it-which kind of horn is more likely to deliver You are There sound, such as all of those mentioned in my last post?
How might this horn and the JBL 2450J work? https://audiohorn.net/next-gen-bi-radial-horn/
Said fishball79 recently said, Altec is punchy but lacks hifi definition [ unlike Pierre's TAD1601B] to match to the beryllium compression driver imo
y/n??
Also, to minimize IMD (overkill in the case of the 416??), Gary Dahl put the Altecs in these 3 cu ft sealed cabinets to play down to 70Hz, below which his subs took over. Troy did measurements at 100Hz @ 90db.
https://josephcrowe.com/blogs/news/altec-416-8b-in-100l-sealed
But fishball79 also said Vintage Altec 416 sound wont gel well with modern servo woofers...
My subs https://www.rythmikaudio.com/F12.html
https://www.rythmikaudio.com/technology.html
https://greatplainsacoustics.com/pr...1a3NwqSy0bXcyUW1cGP7rJhRPltQZa-e3yWqIDV2cUHfq
https://www.technicalaudiodevices.com/lf-units/
Should I be worried?
Recorded polar measurements of what? The room alone? How can that happen without output transducers; namely, speakers? If yes, then how exactly? By playing some kind of sweep frequency WAV files through these El Cheapo speakers I picked up off the street last year and making live recording with a USB mic (which??) to generate what kinds of plots?
https://offerup.com/item/detail/aecb2e01-fde3-3722-8e24-cb5dd89c3a2a
............AND please remember, you're conversing with an ignoramus.
How might this horn and the JBL 2450J work? https://audiohorn.net/next-gen-bi-radial-horn/
Very disappointing loading capabilities for the sizeof of the horn. cut-off looks just below 600hz. The Xover for that would be 1k to 1k2. Do you want that? Ask for the vertical polar. Ask why for all measurements we see a sudden breakdown of directivity control beyond 10k.
Very disappointing loading capabilities for the sizeof of the horn. cut-off looks just below 600hz. The Xover for that would be 1k to 1k2. Do you want that? Ask for the vertical polar. Ask why for all measurements we see a sudden breakdown of directivity control beyond 10k.
Unless, you mean vertical directivity plots of a completed speaker system, as exemplified here.
https://www.vandermill-audio.nl/vertical-directivity-grabbing-the-bull-by-the-horns/
It’s easy to see what I called the “horns” in the title within that vertical directivity plot. Those horns are lobes of energy that develop due to the center to center spacing of the drivers.
If yes, are you serious? We haven’t even settled on a horn/driver combo to use above the Altec 416s; so there’s nothing anywhere near built yet to be able to generate such plots.
Last reply said: I'm currently finishing a mk2 of the bi-radial, measurement will be updated soon and there will be the vertical polar. I don't use BEM, I'm in FEA.
I will ask Nicholas about the loss of directivity control beyond 10K-and will invite him to check us out.
Hi, I'm a little bit surprise by Docali message as I know and greatly appreciate him and have simulate his horn in FEA for him.
Nowadays the effective crossover of a couple between a horn and a compression driver is dictated by group delay.
As phase can be modify easily, just by EQ flat lower with minimum phase, aka IIR filters, EQ (it will correct phase) then cross with linear phase (FIR).
The GD indicate for this horn, that is in fact "tiny", the Mk1 was 44cm including full return, a 700 hz crossover, with LR 48dB ideally "as usual" in pro environment.
In pro and acoustical system we search a perfect match between horn and woofer, usually 15" that in fact can goes higher than we thinks, even old one.
https://audiohorn.net/sciences/directivity-match/
The loading of a system is define by the surface near the throat (not really the overall deep in fact), as @Kolbrek said it his book, he is present on DIYaudio.
As I said too : https://audiohorn.net/sciences/horn-acoustic-loading/
Then when the horn loss the directivity on the bottom (define by wave length > width of the horizontal horn mouth more or less) the loading is no more possible, it's like sending energy in the void, (as Geddes said it too but he don't talk about throat area that have a big impact):
https://audiohorn.net/sciences/horn-and-energy/
Loading is far to be something uniform across frequencies and don't affect HF but directivity affect it...
I don't understand the sentence about the directivity beyond 10k, we on purpose let them fall as, as Geddes said constant direcvity is necessary until 7kHz, I offer 14kHz, between 10 and 14 the 2450 begin to break-up, so it goes outside the plane wave behavior and begin to act differently there is nothing to do about this except do not excite breakup, of whatever compression driver of the market, by searching to be constant until 20 kHz...
Loading doesn't affect HF so, as energy is not free, sending too much energy off axis after 12/14 kHz will lower the curve and give an "anchor point" too low, see image here :
https://audiohorn.net/sciences/hiss-and-horn-response-equalization/
The JBL 2450SL can goes low, the new horn will be larger (48cm as an X-Shape X40 with his returns, that is regularly use at 700hz with 15NTLW3500), and use fractional fins, the first of his kind, the page will be updated when it will be ready with polar in both way, the horn on my page is no more produced.
So the new one will be more usable bellow 700hz, but as the goal is to have a good directivity mach with direct radiation 15", a very low xover is not all the time desirable, moreover, even if a compression driver can goes low, at high SPL bellow 700hz there is no match against a cone one, it's why JBL and other have move the xover close to 700hz with 1.5"/1.4" drivers and horn around 40cm wide (without return so more if you add it, that you should : https://audiohorn.net/mid-range-beaming-and-narrowing/).
Of course it depends of your needs in SPL max, but directivity match at Xover and distortion at high SPL was the point.
We cut where the woofer lost is directivity and match the one of the horn.
For the lobes, if the center to center spacing is good according to crossover lambda it's not a problem, said other wise diffraction will be a lot more impacting, see the GIF here :
https://audiohorn.net/sciences/diffraction-standing-waves/
On modern cross the only physical presence of elements will define at 80/90% the vertical polar response, and even affect the horizontal one.
Midrange narrowing and beaming too of course, if nothing has been done to remove it, again Kolbrek said it too as me and it's proven by measurement.
Making horn is energy management and how to not wast it.
Nowadays the effective crossover of a couple between a horn and a compression driver is dictated by group delay.
As phase can be modify easily, just by EQ flat lower with minimum phase, aka IIR filters, EQ (it will correct phase) then cross with linear phase (FIR).
The GD indicate for this horn, that is in fact "tiny", the Mk1 was 44cm including full return, a 700 hz crossover, with LR 48dB ideally "as usual" in pro environment.
In pro and acoustical system we search a perfect match between horn and woofer, usually 15" that in fact can goes higher than we thinks, even old one.
https://audiohorn.net/sciences/directivity-match/
The loading of a system is define by the surface near the throat (not really the overall deep in fact), as @Kolbrek said it his book, he is present on DIYaudio.
As I said too : https://audiohorn.net/sciences/horn-acoustic-loading/
Then when the horn loss the directivity on the bottom (define by wave length > width of the horizontal horn mouth more or less) the loading is no more possible, it's like sending energy in the void, (as Geddes said it too but he don't talk about throat area that have a big impact):
https://audiohorn.net/sciences/horn-and-energy/
Loading is far to be something uniform across frequencies and don't affect HF but directivity affect it...
I don't understand the sentence about the directivity beyond 10k, we on purpose let them fall as, as Geddes said constant direcvity is necessary until 7kHz, I offer 14kHz, between 10 and 14 the 2450 begin to break-up, so it goes outside the plane wave behavior and begin to act differently there is nothing to do about this except do not excite breakup, of whatever compression driver of the market, by searching to be constant until 20 kHz...
Loading doesn't affect HF so, as energy is not free, sending too much energy off axis after 12/14 kHz will lower the curve and give an "anchor point" too low, see image here :
https://audiohorn.net/sciences/hiss-and-horn-response-equalization/
The JBL 2450SL can goes low, the new horn will be larger (48cm as an X-Shape X40 with his returns, that is regularly use at 700hz with 15NTLW3500), and use fractional fins, the first of his kind, the page will be updated when it will be ready with polar in both way, the horn on my page is no more produced.
So the new one will be more usable bellow 700hz, but as the goal is to have a good directivity mach with direct radiation 15", a very low xover is not all the time desirable, moreover, even if a compression driver can goes low, at high SPL bellow 700hz there is no match against a cone one, it's why JBL and other have move the xover close to 700hz with 1.5"/1.4" drivers and horn around 40cm wide (without return so more if you add it, that you should : https://audiohorn.net/mid-range-beaming-and-narrowing/).
Of course it depends of your needs in SPL max, but directivity match at Xover and distortion at high SPL was the point.
We cut where the woofer lost is directivity and match the one of the horn.
For the lobes, if the center to center spacing is good according to crossover lambda it's not a problem, said other wise diffraction will be a lot more impacting, see the GIF here :
https://audiohorn.net/sciences/diffraction-standing-waves/
On modern cross the only physical presence of elements will define at 80/90% the vertical polar response, and even affect the horizontal one.
Midrange narrowing and beaming too of course, if nothing has been done to remove it, again Kolbrek said it too as me and it's proven by measurement.
Making horn is energy management and how to not wast it.
ditto 😉
But maybe you remember that I already said to you a longer time ago that your horn has a quite high cut-off for the size. I have a few JBL2450SL drivers in my stock, and they can do almost full output to 250Hz in the right horn. And in my WN300ALO they do full output down to 300Hz.
And they do not break-up so heavy (around 17-18k for my copies). The narrowing you observe is never a property of the driver. It is the property of horn. You if you normalize results, what you should do, then it is a pure property of the horn.
Every polar should be normalize yes.
When return is included to the horn it's normal as profile is % less important, on the new one the profile take a more important % in more than the 4cm increase. It's one of the reason there is a new version but not the only one, surface law is still hypex one except on the mouth of course (again Kolbrek book said the same).
No the 2450SL start to breakup from around 8 kHz as it's not a very hard diaphragm, harder the dia upper the breakup but also more violent it will be (cancellation & beam) and the more violent the out of plane wave radiation will be.
With a breakup there is a start and a end, it's a range, damper the diaphragm less violent will be the breakup but longer the range, at the reverse, harder the diaphragm, upper it will be, on a less important range but very violent it can be.
It's a balance between stiffness and damping, as always, it need to be look on temporal measurement (with Burst Decay) not only frequency one.
I still don't understand where is the narrowing for a 1.5" horn that is CD until 14 kHz, with a very light shaking due to breakup between 10 and 14khz, completely not audible.
As I have said upper, constant too high is a bad idea as the anchor point of EQ, that peoples often use is at 14/15khz, and it will be lower in SPL due to opening, if energy is present off axis she will be less present on axis. And loading cannot do something at theses frequencies.
On some driver the breakup finish at 16/17K and the driver restart to open, it create a kind of visible deep, there is solution to avoid this.
Constant directivity horn are more exigent about plane wave behavior of the driver as it will will be very easy to see an exit of the plane wave behavior in HF on it rather than on a Tractrix or something narrowing, for ex.
This kind of shaking is visible so, it can be even worst with Ribbon (not AMT) in plain midrange due to wave radiation that is not plane at some point.
Keep in mind that we don't have the same goal, if somebody want to goes very low with a 2" with a horn doable in DIY I'm sure yours are very good, my market is more pragmatic and professional, they cut at 700hz, at 250hz the voice coil of the 2450 will burn with what ask my client or have to many distortion comparing to a regular 15" at the same frequencies.
It's just two different approach, complementary, but I'm agree that the mk1 is too little of course, the mk2 will allow a lower xover but saying that it haves to be crossed at 1000/1200hz, no, it's a misunderstood about how to define the real crossover point: directivity, group delay, distortion of the driver.
Loading is not at all something uniform, on X-Shape I send a lot of loading just before the end of the control, it's why it allow to be cut so close to an hard slope, when we send loading close to end of control, at the low end, it create a more "vertical" slope, at this point talking about "2*Fc" or "1.5*Fc" is irrelevant.
Again : directivity, group delay, distortion of the driver.
Do you have a polar of your horn with 2450 to show ? It's about the WN300ALO ?
When return is included to the horn it's normal as profile is % less important, on the new one the profile take a more important % in more than the 4cm increase. It's one of the reason there is a new version but not the only one, surface law is still hypex one except on the mouth of course (again Kolbrek book said the same).
No the 2450SL start to breakup from around 8 kHz as it's not a very hard diaphragm, harder the dia upper the breakup but also more violent it will be (cancellation & beam) and the more violent the out of plane wave radiation will be.
With a breakup there is a start and a end, it's a range, damper the diaphragm less violent will be the breakup but longer the range, at the reverse, harder the diaphragm, upper it will be, on a less important range but very violent it can be.
It's a balance between stiffness and damping, as always, it need to be look on temporal measurement (with Burst Decay) not only frequency one.
I still don't understand where is the narrowing for a 1.5" horn that is CD until 14 kHz, with a very light shaking due to breakup between 10 and 14khz, completely not audible.
As I have said upper, constant too high is a bad idea as the anchor point of EQ, that peoples often use is at 14/15khz, and it will be lower in SPL due to opening, if energy is present off axis she will be less present on axis. And loading cannot do something at theses frequencies.
On some driver the breakup finish at 16/17K and the driver restart to open, it create a kind of visible deep, there is solution to avoid this.
Constant directivity horn are more exigent about plane wave behavior of the driver as it will will be very easy to see an exit of the plane wave behavior in HF on it rather than on a Tractrix or something narrowing, for ex.
This kind of shaking is visible so, it can be even worst with Ribbon (not AMT) in plain midrange due to wave radiation that is not plane at some point.
Keep in mind that we don't have the same goal, if somebody want to goes very low with a 2" with a horn doable in DIY I'm sure yours are very good, my market is more pragmatic and professional, they cut at 700hz, at 250hz the voice coil of the 2450 will burn with what ask my client or have to many distortion comparing to a regular 15" at the same frequencies.
It's just two different approach, complementary, but I'm agree that the mk1 is too little of course, the mk2 will allow a lower xover but saying that it haves to be crossed at 1000/1200hz, no, it's a misunderstood about how to define the real crossover point: directivity, group delay, distortion of the driver.
Loading is not at all something uniform, on X-Shape I send a lot of loading just before the end of the control, it's why it allow to be cut so close to an hard slope, when we send loading close to end of control, at the low end, it create a more "vertical" slope, at this point talking about "2*Fc" or "1.5*Fc" is irrelevant.
Again : directivity, group delay, distortion of the driver.
Do you have a polar of your horn with 2450 to show ? It's about the WN300ALO ?
This is not so. While doing what you are attempting can be a good thing, there are other factors involved. This means that the required EQ can not necessarily be tied to the response of a particular axis.
Without EQ interpretation of directivity is pointless.
Dou you want to state that directivity is a function of the driver?
Dou you want to state that directivity is a function of the driver?
You're not taking the point about tying it to an axis. Besides, viewing directivity without appropriate EQ is not pointless, it may just take a little longer to do.
The suggestion that this is what I meant shows you're not taking the point. However since you mention it, the driver does have an effect on directivity.
Cut off is a misleading term as not all horns/wg have it. The most important thing for loading is horn length together with an appropriate mouth area. I have seen a claim for 290hz and effective length of 33cm. My wn300alo has a length of 47cm. But no worries, I am no competitor in the market as my horns will not be available for purchase.
I have read a goal for 500Hz cover here. Not possible imo with these devices discussed here. We need to look at the normalized distortion figures of a combo. Then you can state where the CD should be out of the game.
Btw, horn length cannot be replaced with anything else imo.If you want to say that the mouth area is the determining factor then simply use a zero length horn and a round shim with this area. How much loading you have?
That's a bit disingenuous.
One could equally say: let's take a horn of X length and ~infinite mouth area... that would lead to a virtually flat baffle. Now, how much loading would that give?
Extreme cases like these can be used to "prove" any point and their opposite.
In real-world conditions, several factors are at play and all are important. If one is to be singled out as the most relevant one for the purposes of "loading" the driver, I would suggest expansion rate near the throat as the most relevent one.