slowmotion said:
Agreed. It takes a lot of cut and try. Unless you're a mathematical modelling expert (and perhaps even if you are), predicting performance from paper specs is really difficult.
Yes! Once again I agree.
I used a large 18-cell exponential midrange to 300Hz. Beautiful.
One thing I don't like about single cell non-conical horns is the narrowing of the pattern with increasing frequency. When I say I don't like it I'm not being pedantic about the specs - I don't like the way it sounds. You can hear it in the reverberant field even on-axis. Some people seem to prefer it though, so I view it as a matter of preference rather than right or wrong.
rick57 said:
I've never had an opportunity to listen to them, but you knew that already. And like I said before the sound depends on the horn, too. My experience would mean almost nothing in your situation unless we were using the same horn.
It's an album cover, but I'm not telling who it is.
slowmotion said:
I have that site bookmarked, too. I forgot about it completely. The guy had prices up there at one time. I think he was selling them for around $15,000USD / pair. That was without the drivers, which would set you back over $5,000 USD for a pair if you could find them.
Still, ALE gear makes these prices look cheap!
jeff mai said:
Edit: ...but you knew that already didn't you?
It seems like we discussed this before. The Beyma's never made it beyond the test bench.
Although some people have said the Beymas can sound nice, I'm skeptical about mylar vs aluminium or even phenolic. Mylar just couldn't be rigid enough could it? Someday I'll find out. Those Beymas are too small for 300Hz anyway.
jeff mai said:
Yes, I agree, that can be a problem.
A well defined horisontal coverage is a plus.
Not so easy if you want the horn to load the driver like an exponential horn.
So axisymmetric horns are probably not the way to go, at least not for me.
There's lots of different opinions about this, tho,
a lot of different paths to the top of the mountain
cheers
Hi Jeff & Jan
Beymas - a while back IIRC you hadn’t listened, I thought you may have since.
> And like I said before the sound depends on the horn, too.
Yes, but it is some guide, to one who has heard less than a handful of horns, and only got intested two weeks ago.
The album cover – that’s a hard one
WE15A replicas $15,000USD. Next idea.
> a lot of different paths to the top of the mountain
Yes, many it seems. I’m just looking for the faster track, preferring more research and less experimentation.
Another driver option - JBL 2482s “on Sato horns down to 200 Hz” whatever Sato horns are
Cheers
time for R&R
Beymas - a while back IIRC you hadn’t listened, I thought you may have since.
> And like I said before the sound depends on the horn, too.
Yes, but it is some guide, to one who has heard less than a handful of horns, and only got intested two weeks ago.
The album cover – that’s a hard one
WE15A replicas $15,000USD. Next idea.
> a lot of different paths to the top of the mountain
Yes, many it seems. I’m just looking for the faster track, preferring more research and less experimentation.
Another driver option - JBL 2482s “on Sato horns down to 200 Hz” whatever Sato horns are
Cheers
time for R&R
Miguel
Great link – yes nice horn! May be somewhat beyond my wood skills . .
Jeff
I may not have 100 % grasp of the situation, so thanks for the warning
Cheers
The we15a replica is 7500 Euro/ pair (that can fit through normal doors. 500 Euro off if your doors are at least 110 cm width), including wood crate for shipping.
Manufacturing time is 3 months.
Quicktime clip:
http://www.melaudia.net/zfoto/gene/visiteAldo.mov
From the manufacturer Aldo:
About we15a frequency response :
my we15b is run full range but there's a RCA mi-9472A autotransformer in parallel with we555 only that acts slightly as bandpass , avoiding very low frequencies ( below 50Hz) to reach the we555. Rca autotrans is somewhat limited in low frequency , and helps in this job. Autotrans is useful to match impedance too : we555 in parallel are 8 Ohm , instead tweeter and woofers usually are 16Ohm. So with autotrans I bring we555 to 16Ohm.
the we15a has a lower cutoff of 57Hz, so until the lowest frequencies that reach we555 are in that range, the we555 will work properly and will not be damaged. so it's necessary to reduce the frequencies below 57HZ ( 6db slope is enough ). This is accomplished by RCA autotrans and by some frequency limitations in amplifier chain. WE amps of 1930-1940 have low frequency response flat till 40 Hz , not till 20 Hz like modern designs.
the bass speaker on my system is cut by a simple , but large , coil : 120 hz 6db.
the tweeter is cut at 3000Hz 12db.
the frequencies above 3000hz are cut in the we15 in mechanical way : a felt or flannel large piece is put in the mouth.
regardless to lowest cutoff of 57hz , the we15a is flat from 120Hz to 3000Hz.
All the criteria above are stated by WE in 1939 : the felt , the fullrange operation , the crossover frequencies...I have tried to cut the 15a differently , but WE engineers were right...
best regards
Aldo
Great link – yes nice horn! May be somewhat beyond my wood skills . .
Jeff
I may not have 100 % grasp of the situation, so thanks for the warning
Cheers
The we15a replica is 7500 Euro/ pair (that can fit through normal doors. 500 Euro off if your doors are at least 110 cm width), including wood crate for shipping.
Manufacturing time is 3 months.
Quicktime clip:
http://www.melaudia.net/zfoto/gene/visiteAldo.mov
From the manufacturer Aldo:
About we15a frequency response :
my we15b is run full range but there's a RCA mi-9472A autotransformer in parallel with we555 only that acts slightly as bandpass , avoiding very low frequencies ( below 50Hz) to reach the we555. Rca autotrans is somewhat limited in low frequency , and helps in this job. Autotrans is useful to match impedance too : we555 in parallel are 8 Ohm , instead tweeter and woofers usually are 16Ohm. So with autotrans I bring we555 to 16Ohm.
the we15a has a lower cutoff of 57Hz, so until the lowest frequencies that reach we555 are in that range, the we555 will work properly and will not be damaged. so it's necessary to reduce the frequencies below 57HZ ( 6db slope is enough ). This is accomplished by RCA autotrans and by some frequency limitations in amplifier chain. WE amps of 1930-1940 have low frequency response flat till 40 Hz , not till 20 Hz like modern designs.
the bass speaker on my system is cut by a simple , but large , coil : 120 hz 6db.
the tweeter is cut at 3000Hz 12db.
the frequencies above 3000hz are cut in the we15 in mechanical way : a felt or flannel large piece is put in the mouth.
regardless to lowest cutoff of 57hz , the we15a is flat from 120Hz to 3000Hz.
All the criteria above are stated by WE in 1939 : the felt , the fullrange operation , the crossover frequencies...I have tried to cut the 15a differently , but WE engineers were right...
best regards
Aldo
Hi Rick, I suspect the only "faster track" way is to build something already designed and tested. This is a nice system:
http://www.diy-systems.com/en-us/dept_1.html
I've seen some pics around here somewhere, someone is using the Oris with dipole bass underneath.
Did you decide on what driver you are using up to 300 Hz?
JohnR
http://www.diy-systems.com/en-us/dept_1.html
I've seen some pics around here somewhere, someone is using the Oris with dipole bass underneath.
Did you decide on what driver you are using up to 300 Hz?
JohnR
- I've used the 4590 for a couple of years on a variety of horns and it's an excellent driver. I nearly bought the 4592, but it was still a few months from release at the time and I was impatient; it was also nearly 3x the price. May get some to play with later.rick57 said:
- P.Audio BM series are good, but not great, excellent value for money.
- JBL 2445 and 2446 are excellent drivers, with the 2446 being better to my ears.
No experience with the others. I've used all of these domestically and in small PA's.
I know where there are some new 2446 for a decent price. Email for details if interested.
Hypex is an abbreviation of hyperbolic.rick57 said:
I've only used the CP380M, but it's a peach. I'm going to order another for my bass rig when I order the 15G40's.
Yep. Stiff cardboard and art boards are good for messing with prototypes.jeff mai said:
Depends a lot on the room too. Mine is very wide with the speakers pointing across it (still about 10m) so it doesn't matter so long as I'm in the sweet spot.
Lots of sawdust later, I agree totally.
Hi JohnR
I agree that that the Oris is a "faster track". However they use Fostex or AER drivers – I am quite keen on using a compression driver.
> Did you decide on what driver you are using up to 300 Hz?
No, that’s a separate thread. If I had to lay my money & time down right now, I’d say a double stack of the Linkwitz Phoenix W baffles. Though I’m trying to see if there’s something with with more punch, other than a midbass horn.
Some (including indirectly Magnetar) suggest a Karlson,
it may just be a voodoo vented variant.
Cheers
Richard
I agree that that the Oris is a "faster track". However they use Fostex or AER drivers – I am quite keen on using a compression driver.
> Did you decide on what driver you are using up to 300 Hz?
No, that’s a separate thread. If I had to lay my money & time down right now, I’d say a double stack of the Linkwitz Phoenix W baffles. Though I’m trying to see if there’s something with with more punch, other than a midbass horn.
Some (including indirectly Magnetar) suggest a Karlson,
it may just be a voodoo vented variant.Cheers
Richard
rick57
The "plane wave tube" is just a device used to separate the horn's contributions, whether good or bad, from the driver's actual response. Though I've never actually played with one, it's a tool, really, which provides a load for the driver to operate into without grossly affecting the output, so that you can get a better notion of the unit's bandwidth, power response, frequency response, etc. Once the driver is mounted back on a horn, you can measure the output again to see plainly how the horn has altered response from a "base" driver measurement on a tube.
http://www.aes.org/standards/b_pub/aes-1id-1991-r2003.pdf
2" driver = 2" ID plastic tube, stuffed, with a sealable port for the measurement microphone.
Tim
The "plane wave tube" is just a device used to separate the horn's contributions, whether good or bad, from the driver's actual response. Though I've never actually played with one, it's a tool, really, which provides a load for the driver to operate into without grossly affecting the output, so that you can get a better notion of the unit's bandwidth, power response, frequency response, etc. Once the driver is mounted back on a horn, you can measure the output again to see plainly how the horn has altered response from a "base" driver measurement on a tube.
http://www.aes.org/standards/b_pub/aes-1id-1991-r2003.pdf
2" driver = 2" ID plastic tube, stuffed, with a sealable port for the measurement microphone.
Tim
rick57
Here's a scarey one that will go low on the right horn:
http://www.jblpro.com/pages/pub/components/2490.pdf
Titanium diaphragm, though, with 3" exit, 4" coil.
Here are combinations of drivers that are placed in kits, which I think has merit, but I've not heard any of them.
http://www.assistanceaudio.com/09_kits.html
You should probably hear various horn rigs in a home setting. I like around 90 - 100 degree dispersion, so I would look at horns close to that. Could vary somewhat, but "short throw" in the pro world.
They very much like the BMS compression drivers.
Tim
Here's a scarey one that will go low on the right horn:
http://www.jblpro.com/pages/pub/components/2490.pdf
Titanium diaphragm, though, with 3" exit, 4" coil.
Here are combinations of drivers that are placed in kits, which I think has merit, but I've not heard any of them.
http://www.assistanceaudio.com/09_kits.html
You should probably hear various horn rigs in a home setting. I like around 90 - 100 degree dispersion, so I would look at horns close to that. Could vary somewhat, but "short throw" in the pro world.
They very much like the BMS compression drivers.
Tim
Then it seems reasonable to me that a ~one octave larger Unity concept is the no-brainer solution if there's enough space for a 'good midrange horn'.
Hmm, unless it has changed in recent years it refers to the range of 'M' factors above hyperbolic (o.5) and below exponential (1.0), with 0.6-0.7 being a nice compromise between the two.
?! I didn't need any with mine (as measured with an RTA/pink noise, not to mention my ears), so I guess I got lucky.
Hypex is fine for midbass, but mids require low distortion and good pattern control, so IMO a large conical, or at least an expo radial with a large flare end correction ala' tractrix mouth, L'Cleach, or similar is required. That, or make the horn at least an octave larger than the -12dB XO point.No VooDoo, just innovative engineering, which like the Unity concept is an elegant solution to a thorny acoustic conumdrum IMO. Anyway, it's a multiple stage reflex loaded wide BW bandpass. IOW in effect it's a very large compression driver with a ~aperiodic vent, though IMO it doesn't perform anywhere near as well overall as its marketing hype and ~fanatical admirers would have you believe. Maybe if it had been marketed as a 'bass' module with sturdier construction and an XO so you could put a sealed or dipole 'FR' driver or large wide BW horn on top it would have been a commercial success instead of being relegated to the audio 'snake oil' pile. That said, with the 'right' driver it will favorably compete with a true midbass horn, so BW limited to ~ a couple of octaves it's a viable alternative IMO if you make it rigid/air tight enough.
Ask Freddy Ireson over on the HE forum for a copy of his measurements with an Altec 421 ( a good match if SS or low output resistance tube p-p driven) to get an idea of what kind of performance the 'K' is capable of in the ~40-160Hz BW.
If you're willing to trade some efficiency for BW and use more drivers/larger cab, then the R-J BP loading method (patent #2,694,463) works well if you don't want to go through the hassle of building a more space efficient radial horn.
FWIW, I draw up the room to scale to find what max vertical/horizontal dispersion keeps the signal from hitting a boundary until it's behind the desired listening area, though I imagine folks with more math skills than me can just use dims/geometry to calc them.
GM
Hi GM,
I just move my seat or adjust the horn. That's what paperbacks are for.
Always exceptions, as you know, but there are few mid/hi horn commercial offerings for domestic use that aren't ~90-100 degree horizontal 40-50 degree vertical dispersion, at least in what I have come in contact with. Any narrower and they pin your ears back; wider and its too diffuse, involves too much of the room for my taste.
I am curious about the potential for matching the exit flare on the driver to that of the horn, and well as alterations to the phasing plug that Bill Woods has mentioned. There seems to be a big disparity there when coupling say a 2440 2" 300 Hz exit flare to a 500 Hz or higher horn. Bill says the exit flare sets up the dispersion angle to a greater extent than many would think, with the horn able to recapture only some, not all, of this back, if I understand him correctly.
Need to experiment with machining out the flares. Got any volunteers?
Tim
I just move my seat or adjust the horn. That's what paperbacks are for.
Always exceptions, as you know, but there are few mid/hi horn commercial offerings for domestic use that aren't ~90-100 degree horizontal 40-50 degree vertical dispersion, at least in what I have come in contact with. Any narrower and they pin your ears back; wider and its too diffuse, involves too much of the room for my taste.
I am curious about the potential for matching the exit flare on the driver to that of the horn, and well as alterations to the phasing plug that Bill Woods has mentioned. There seems to be a big disparity there when coupling say a 2440 2" 300 Hz exit flare to a 500 Hz or higher horn. Bill says the exit flare sets up the dispersion angle to a greater extent than many would think, with the horn able to recapture only some, not all, of this back, if I understand him correctly.
Need to experiment with machining out the flares. Got any volunteers?
Tim
Hey John,
Thanks for the offer, but until I get a sacrificial lamb, I might just try measuring and matching at the horn throat, possibly include the EG flare profile on my next experiment. I guess it is no wonder the 300 Hz horns sound good with the JBL 2440/2441 drivers.
What is your impression of the 2482 compared to the 375 driver?
Didn't you have the large conical on it at home?
Tim
Thanks for the offer, but until I get a sacrificial lamb, I might just try measuring and matching at the horn throat, possibly include the EG flare profile on my next experiment. I guess it is no wonder the 300 Hz horns sound good with the JBL 2440/2441 drivers.
What is your impression of the 2482 compared to the 375 driver?
Didn't you have the large conical on it at home?
Tim
(just GM for now)
Hi GM
Wouldn’t a ~one octave larger Unity just go one octave lower? To get more dynamics and especially detail, would the answer be better (probably compression) drivers?
> Hypex is fine for midbass
If conical works well in the mids, how about (easier to build rectangular) conical for midbass too?
Great comments on the Karlson! Apparently for a good Karlson driver you want low Fs and low Q. I have yet to learn how top extend the top end of the bandpass, say to 450 Hz.
**So with the 'right' driver do you think it will favourably compete with a true midbass horn 70-450 Hz??
At this stage it’s likely either a * Karlson
with Beta 15CX http://home.earthlink.net/~buddhaboy2/RW/K15Beta15CX.jpg has the best bandwidth, or
cheaper and maybe better (much lower Qts good better for Karlson; bigger voice coil; nearly double Xmax; and with Fs/ Qts of 121 could also be used in a horn) Eminence 151311.
* Or a horn (shape to be decided) with either Eminence: 151311, Delta-12A, Delta Pro-12A, Kappa-12A, Kappa Pro -12A and a coupla others. Some PHL or B & C would be good, but a little dear.
Fs/ Qts of these ranges from 121 – 167.
I have yet to learn what are the other critical factors to select a good midbass horn driver?
It’d be good to get a pair of the Eminence 151311, build one of each (K & H) and compare, but here (as Madisound won’t surface fright overseas) they’re way more than $US 90, and especially as each would take more than most to optimise.
Is the Altec 421 only capable up to 160 Hz? To mate to a 2 inch compression driver, I need to get to about to 450 Hz.
Can you outline or de-acronymize the R-J BP loading method?
> I draw up the room to scale to find what max vertical/horizontal dispersion keeps the signal from hitting a boundary
Damn fine idea!
Cheers
Hi GM
Wouldn’t a ~one octave larger Unity just go one octave lower? To get more dynamics and especially detail, would the answer be better (probably compression) drivers?
> Hypex is fine for midbass
If conical works well in the mids, how about (easier to build rectangular) conical for midbass too?
Great comments on the Karlson! Apparently for a good Karlson driver you want low Fs and low Q. I have yet to learn how top extend the top end of the bandpass, say to 450 Hz.
**So with the 'right' driver do you think it will favourably compete with a true midbass horn 70-450 Hz??
At this stage it’s likely either a * Karlson
with Beta 15CX http://home.earthlink.net/~buddhaboy2/RW/K15Beta15CX.jpg has the best bandwidth, or
cheaper and maybe better (much lower Qts good better for Karlson; bigger voice coil; nearly double Xmax; and with Fs/ Qts of 121 could also be used in a horn) Eminence 151311.
* Or a horn (shape to be decided) with either Eminence: 151311, Delta-12A, Delta Pro-12A, Kappa-12A, Kappa Pro -12A and a coupla others. Some PHL or B & C would be good, but a little dear.
Fs/ Qts of these ranges from 121 – 167.
I have yet to learn what are the other critical factors to select a good midbass horn driver?
It’d be good to get a pair of the Eminence 151311, build one of each (K & H) and compare, but here (as Madisound won’t surface fright overseas) they’re way more than $US 90, and especially as each would take more than most to optimise.
Is the Altec 421 only capable up to 160 Hz? To mate to a 2 inch compression driver, I need to get to about to 450 Hz.
Can you outline or de-acronymize the R-J BP loading method?
> I draw up the room to scale to find what max vertical/horizontal dispersion keeps the signal from hitting a boundary
Damn fine idea!
Cheers
Hey Tim,
True, but this thread is about DIY, so I figured might as well at least get the basic profile right anyway. WRT how the wall angle affects gain, you have to pick the right length to get the proper gain so it doesn't 'shout'. That or use mass quantites of EQ.
Not quite sure what you're referring to, but for sure you need to have as seamless a transition at the driver/horn junction as practical for best performance, flaring it based on the desired HF response first, then adjusting the flare as required as the horn marches down in frequency towards the mouth, so no abrupt transitions till fairly near the mouth is one of my mottos, which should be at least an octave larger than the desired cutoff if the flare rate is to be maintained.
Also, all the compression drivers I've used had short conical exits, so no definable flare rate, only what HF BW it controls, so please explain how one can have a 300Hz flare rate.
WRT tweaking the phase plug, never tried it, just mostly worked with what I liked, Altecs. So what did he suggest?
GM
True, but this thread is about DIY, so I figured might as well at least get the basic profile right anyway.
WRT how the wall angle affects gain, you have to pick the right length to get the proper gain so it doesn't 'shout'. That or use mass quantites of EQ.Not quite sure what you're referring to, but for sure you need to have as seamless a transition at the driver/horn junction as practical for best performance, flaring it based on the desired HF response first, then adjusting the flare as required as the horn marches down in frequency towards the mouth, so no abrupt transitions till fairly near the mouth is one of my mottos, which should be at least an octave larger than the desired cutoff if the flare rate is to be maintained.
Also, all the compression drivers I've used had short conical exits, so no definable flare rate, only what HF BW it controls, so please explain how one can have a 300Hz flare rate.
WRT tweaking the phase plug, never tried it, just mostly worked with what I liked, Altecs. So what did he suggest?
GM
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