Thanks Cal.
TBH it MUST be easier to build up the number of cells you intend to use and then fix them together - as opposed to make the cells up, fix them together and then cut them flush all the while making the outer cells walls chamfered etc etc?
So what are the ramifications of the way the guy builds his horns? ie, cells starting from a flat plane, longest cells at the centre, shortest at the edge and odd wall thicknesses to get mouth sizes equal?
TBH it MUST be easier to build up the number of cells you intend to use and then fix them together - as opposed to make the cells up, fix them together and then cut them flush all the while making the outer cells walls chamfered etc etc?
So what are the ramifications of the way the guy builds his horns? ie, cells starting from a flat plane, longest cells at the centre, shortest at the edge and odd wall thicknesses to get mouth sizes equal?
multicell horn construction
Pano,if you do decide to experiment with a different gasket and honing the transition would you please take as many measurements as possible? I am still very much interested in cloning the 1005 and have even been looking on ebay for a reasonably priced specimen that I can measure myself and later resell. You have posted some great photos here and in other threads and I think I could come close to the original by scaling the pictures. Close is not good enough for a project this involved.
Pano,if you do decide to experiment with a different gasket and honing the transition would you please take as many measurements as possible? I am still very much interested in cloning the 1005 and have even been looking on ebay for a reasonably priced specimen that I can measure myself and later resell. You have posted some great photos here and in other threads and I think I could come close to the original by scaling the pictures. Close is not good enough for a project this involved.
We are hoping that you will buy a set and tell us!
Oh that I had £360 to burn. Thats probably all they'll give me for my car
. The guy seemed amenable to altering the throats so I might be able to get a pair with throats as per Cal's pic.
What differences would different length cells bring? Its kind of starts as a sectoral horn (vanes right up to a flat opening) and ends up multicellular. The outermost cells must be tuned to a different frequency....i guess? What he says about the outer wall length sorting it all out can't be right as the lobe emanating from the cell should be from the centre but it would be skewed the way the cells are now - maybe?
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Ok he's come back with a bit more info - "yes the cells are slightly shorter on the outside banks but the throats make up the differance by being longer on the outside edges"
Does anyone out there speak 'multicellular' fluently? Pano, how are the start of the throats arranged in your horns? Cal maybe you can shed some light?
I doesn't seem 'right' to me
Well, I view a multi-cell as a tightly packed cluster [array] of single horns with one or more grouped to focus on a particular area/distance. From this we see that the cells won't necessarily all be the same design/shape and why there can be 10 dB [or more] difference between one 'cluster' and another in a large multi-cell since the core cluster will be focused long/wide while the lower L_C_R clusters will focus the area in between it and the stage/screen while the upper L_C_R will cover the balcony/cheap seats, all of which will increasingly collapse with decreasing frequency as each cluster, then horn, loses pattern control.
Their acoustical path-length should all be the same since it’s what sets the horn’s Fp [1/4 WL cut-off].
The answer then as to how to use them at home is the same as was done in stereo cinema and generally the best way to do a ‘shouty’ ~full-range driver, which is essentially what the large multi-cells are designed to mimic on a grand scale, i.e. point the left channel directly at or slightly above and/or beside the far right seating area and vice versa depending on how ‘hot’ its HF is; preferably located vertically either above or below seated ear height to focus/maximize the diffuse sound field to the left, right and behind the LP, rather than in front of, due to early reflections.
Since each cell is basically a tweeter horn, more is always better in a HIFI/HT app since at some point our hearing system overloads and internally sums them to a single point source plus the larger the horn, the lower, more focused its directivity [pattern] control, minimizing room interaction in front of the LP.
GM
PS: a bit of ‘eye candy’, Jensen’s relatively diminutive [32] cell [basically a divided up 805 IIRC]:
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ok - so I may be able to use 'some' of the insurance money from the car crash for a pair of drivers. As I have my Emkens and a set of Eminence Beta 15's I thought I'd go for the HF driver first.
Looking at the FaitalPRO HF144 details, it gives 2 'maximum power above...' figures. The first is at 0.9Khz of 160w and the second is at the lower figure 0.65khz of 80w (or half again for AES power figures). The recommended lowest crossover freq. is 900hz.
Can I take it from these figures that I 'could' cross over at 650hz, albeit not playing at concert levels? (80w/40wAES) Just wondering for playing about with crossovers etc
Crossing over above the main vocal range 1.5khz-2khz has the benefit of one driver dealing with that important 'band'. But dropping the crossover to 650hz-900hz lets me get more sound thru the horn....
Looking at the FaitalPRO HF144 details, it gives 2 'maximum power above...' figures. The first is at 0.9Khz of 160w and the second is at the lower figure 0.65khz of 80w (or half again for AES power figures). The recommended lowest crossover freq. is 900hz.
Can I take it from these figures that I 'could' cross over at 650hz, albeit not playing at concert levels? (80w/40wAES) Just wondering for playing about with crossovers etc
Crossing over above the main vocal range 1.5khz-2khz has the benefit of one driver dealing with that important 'band'. But dropping the crossover to 650hz-900hz lets me get more sound thru the horn....
From what Bill found in his big compression driver test, at domestic levels you won't run into trouble within the pass band. But all the CDs he tested started to distort badly far below their maximum rated power.
As for crossing low, I've found that depends very much on the horn. At horn cut-off, distortion rises sharply and response falls rapidly. You should cross at least an octave above that. I'm sure that there are some 1" drivers that won't do well at 650Hz, even on a big horn, but the HF144 should not have any trouble on a suitable horn. Can't be sure without seeing measurements, but I doubt you'll have any trouble.
Bottom line. With a decent 1.4" or 2" driver, the horn will be the roadblock to crossing low.
As for crossing low, I've found that depends very much on the horn. At horn cut-off, distortion rises sharply and response falls rapidly. You should cross at least an octave above that. I'm sure that there are some 1" drivers that won't do well at 650Hz, even on a big horn, but the HF144 should not have any trouble on a suitable horn. Can't be sure without seeing measurements, but I doubt you'll have any trouble.
Bottom line. With a decent 1.4" or 2" driver, the horn will be the roadblock to crossing low.
Thanks Pano. Is that the thread by weltersys you are noting above? if not please can I have a linky?
does the resonance peak occur with the impedance peak in CD drivers? I can easily get away with low power listening at home and then change the crossover for out and about use at higher volumes. The joys of the minidsp await!! (not sure about feeding it my vinyl collection thou - any thoughts anyone?)
I'll use this while I get used to the sound & save up for something more.....um......horny
does the resonance peak occur with the impedance peak in CD drivers? I can easily get away with low power listening at home and then change the crossover for out and about use at higher volumes. The joys of the minidsp await!! (not sure about feeding it my vinyl collection thou - any thoughts anyone?)
I'll use this while I get used to the sound & save up for something more.....um......horny
JRKO,
FYI, i have been reading about the minidsp while waiting, and it has some noise issues with high efficiency systems. Gain structure becomes very important or noise is an issue. I wasnt sure if you were considering it as XO unit, having mentioned it to me. I have not heard these issues with Behringer.
FYI, i have been reading about the minidsp while waiting, and it has some noise issues with high efficiency systems. Gain structure becomes very important or noise is an issue. I wasnt sure if you were considering it as XO unit, having mentioned it to me. I have not heard these issues with Behringer.
Do you mean 14" as in 13.8" mouth width or was it a 1.4" without the decimal?
I'll have to look into the minidsp hi eff noise issue (any threads welcome). As I understand it the Behringer units can cause issue because they run at 7v or so because they are pro balanced units.
I'm still not sure about shoving a perfectly good analogue signal thru the ADC-DAC system but thats another storey & more reading........
I meant the mouth width. I was being kind rounding up to 14". FWIW, the Altec 811 has a mouth width of 18" and it's called an 800 Hz horn. Cut-off is about 500 Hz. As much as the modern marketing departments try, the laws of physics are hard to bend.
Settlement cheque arrived in the mail!! Breakers yard had 2 of my model in unknown colours. Drove up with a friend and searched among 2000 odd cars. The first one we found was green. A little more searching and we found the second one - an exact match in colour and trim !!!BONUS!!! Also picked up a bumper as mine had a bad respray that is peeling. Not bad for £100 all in.
Parts are stored in a mates big garage awaiting a rainy day (awaiting??) when he's free to help fit them
Now I have a few pennies to spend on drivers and taking the very supportive & patient Mrs JRKO out for a meal.
Parts are stored in a mates big garage awaiting a rainy day (awaiting??) when he's free to help fit them
Now I have a few pennies to spend on drivers and taking the very supportive & patient Mrs JRKO out for a meal.
and now for drivers
Faital Pro HF144 looks good to me. It will give me some latitude in crossover freq., has the recommended Ketone Polymer diaphragm, is a 1.4" driver with slightly higher power rating, lower crossover point, and maybe a few more horns are available for 1.4"(?).
Before I press the button at the end of the week are there any other suggestions for around £150 a pop?
Faital Pro HF144 looks good to me. It will give me some latitude in crossover freq., has the recommended Ketone Polymer diaphragm, is a 1.4" driver with slightly higher power rating, lower crossover point, and maybe a few more horns are available for 1.4"(?).
Before I press the button at the end of the week are there any other suggestions for around £150 a pop?
heres another W Onken shot for you Pano, from Analog Forum 2012
Cant wait until Friday - I can order my 144's!!!!! still open to other options in the price range. I'll take silence as approval......
Cant wait until Friday - I can order my 144's!!!!! still open to other options in the price range. I'll take silence as approval......
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