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We have turned around from the time of Klipschīs request for a good 5 watt amplifier for his super efficient corner horn!! What I and the world needs is a good 10-12" LF driver designed for horns. I am aware of the standard fare that everybody uses but a driver capable of 2-3" or MORE of Xmax while maintaining mechanical and mag flux linearity is still pending. The cab design a compact 1/2 wavelength horn is already in the drawing board but driver manufacturers have not come thru with the needed driver!! What is the best driver presently out there for this purpose?
Rafaro
Follow Ups:
My horns speakers came with twin 10" drives in each of 2 sub cabinets. Avantgarde. Not DIY - I have no idea of their Xmax!
Edits: 02/08/16
"A compact but expandable subwoofer horn cabinet 1/2 wavelength at 35 Hz with a 10" driver has already been designed but the driver requires an Xmax of about 30mm for maximal performance. Manufacturers have not yet reached this potential that I am aware of but maybe somebody knows different??"
Rafaro,
15mm Xmax has become relatively common, a pair of 15mm drivers would outperform a single 30mm driver (especially in smaller cones where an ultra long throw surround becomes an appreciable % of Sd), and probably be less expensive and handle more power. Power handling becomes a limiting factor for very long excursion drivers, as each doubling of Xmax requires four times the power, and a heavier, less sensitive cone to keep from buckling. A dual (or quad) driver compression chamber may need to be a bit larger, but that size is minimal by comparison to the overall volume of a low frequency horn.
Art
Hello Art :Good suggestion (with good science behind it) to use multiple drivers to make up for the limited Xmax. A compression chamber may be a good idea not only to limit HF which the folding will also limit but to reduce throat distortion from the high pressure in this design. The Xmax limitations in drivers led me to experiment with suspensions and voice coils trying to overcome this limitation. I think Xmax can be significantly increased and magnetic flux linearity maintained but it will require "intelligent" voice coils and more than one spider. Thanks
Rafaro
Edits: 02/14/16
" What I and the world needs is a good 10-12" LF driver designed for horns."
Is too vague to approach scientifically. Even if dealing with a "perfect horn", the issue is one needs to know the low and high cutoff at a minimum and realistically some other data too before one can figure out what the ideal driver for that horn looks like.
If you want to find the ideal driver for a given horn and bandwidth or the ideal horn parameters for a given driver and bandwidth, study this paper.
http://users.ece.gatech.edu/mleach/papers/HornPaper/HornPaper.pdf
Then, since what people usually build are horns that are not ideal, then model what your considering in Akabak or horn resp which appears to be good. With akabak one can model nearly anything one can dream of as parsed into something like a pspice like model and it's easy to change the driver or horn values.
Essentially all of the Synergy horn and Tapped horn products at work were designed using it and it's free!
Best,
Tom Danley
Hello Tom and groupThe design is a sub bass horn of 1/4 wavelength (WL) at 17 Hzs but in reality I am interested in PA live sound setting and maximal SPL at 35 Hzs. By using a horn of 1/4 WL at 17 Hzs response should increase about 4-5 dB at 35 Hzs because at that freq and above the horn will be operating as a 1/2 WL horn. Will keep mouth sized to Perimeter=1/4 of a 35Hz WL not to 17 Hzs. This will limit fundamental to about same level as 2nd and 3rd harmonic at 35 Hz for a very SOLID 35. This truncated 1/2 WL horn idea came from analysing TUBA sound spectrums. An upper freq response of 100 Hzs or more is sufficent
To keep cab size reasonable will use a 10" driver. Therefore need a 10" driver with high BL, EBP (over 130) and the most Xmax. Fs should be around 25-30 Hzs if used to reach 17Hz but as really just want response for PA use at 35 Hzs drivers with Fs about 45 will give a better power response at 35 Hz. Any suggestions appreciated.
Modeling this design in the long past showed a maximal response needed an Xmax of about 30mm. Off the top of my head horn length was 192", with a doubling rate of 42", Throat was 19 sq ". Mouth size could be adjusted up to 8 feet wide since the outer panels are hinged but will keep mouth Perimeter= 1/4 of a 35Hz WL
Hope the details help
Rafaro
Edits: 02/18/16 06/09/16
Try car audio woofers.This 10" has allegedly an Xmax of 25mm or more (Xdamage 4" p-p), Fs is 43Hz and costs Ģ400 in the UK.
Edits: 02/06/16 02/06/16
Why reinvent the wheel? EVM 12L is one of the best drivers for horn application.
Maybe for midrange, but not so much for maximum bass output.
In general, for a bass horn we want the mass corner to be no higher than the crossover point we want to use. The lower the mass corner, the higher the excursion, the higher the maximum output.
The 2226 has the same sensitivity below 200hz as the more efficient, higher mass corner D130. With it's much higher x-max it will have at least 6dB more output below 200hz.
A pair of high excursion 15's in a single corner horn, 146+dB without running out of x-max (60mm P-P).
Stiff laminated hex cone.
You may be right. Except I thought we were discussing 10-12" drivers, not 15".
Can't see the point?
CSS makes a 12" version of the same driver.
RCA made a 2" entry horn with an 80" mouth that had a 30hz taper rate, IIRC it was more than 12' deep.
Tens, twelves, whatever, you're not going to have a good result trying to run a driver with Fs twice the intended horn Fc. Nor is there any need to go to a fifteen inch driver for a 30Hz or lower horn. My 30Hz home theater horn sub is loaded with an eight.
Wow! For flat response down to 30Hz I would never consider anything less than 18". How did you do it and where's F3?
> For flat response down to 30Hz I would never consider anything less than 18". How did you do it...
Use an eleven foot long horn.
My 35Hz horn sub uses EVM18B and is almost 10 feet long. You mean one additional foot allowed you to achieve 30Hz with an 8" driver? Again, where was the F3 point?
F3 is 27Hz.
The low corner is mostly path length.
Use a tapped horn and one can go farther down with small drivers, like this one from work;
http://www.danleysoundlabs.com/products/subwoofers/tapped-horns/th-spud/
"a driver capable of 2-3" or MORE of Xmax while maintaining mechanical and mag flux linearity is still pending."
Let's think about surround, spider, magnet, voice coil, reliability, and cone movement speed.
Two inches to three inches, linearly? What are you smoking?
...
I'll post this as soon as the pop-up message at the bottom of the screen gets out of the damn way so that I can click on the f-ing "Post" button. So far, it's been over two minutes. Right now, it's about 4:51:50.
Finally, at this post time!
5:08:00 pmApprox.
time.gov
Now. it's approx 5:12:30
:)
Edits: 02/03/16
The problem is in part that there is a great deal of "thumb rule" involved with horn design. At the same time, there are very good design tools available now that were only dreams 20 years ago but these require that you know what your looking for.
For example, the "ideal horn driver" looks very different depending on what bandwidth you are looking for.
So, what is it you want to do?
Best,
Tom
Hello Bill and groupIn my modeling of 10-12" driver sub woofer horns the limiting factor in producing high SPL DEEP bass has always been the Xmax more than the power tolerance of the driver. This negates the advantages of 10-12" drivers... the sturdy the cones, the good power tolerance with 3" or greater diameter VC. There has been, over the last 20 or so years, improvement in driver design. The use of 2 or more points of magnetic interaction with the VC by using 2-3 magnets gives a stronger push to the cone but Xmax has seen little improvement. Experimentation with driver suspensions has shown me that there is potential for several inches of Xmax but the difficulty has been in maintaining magnetic flux linearity along the contact point(s) of the V.C.
A compact but expandable subwoofer horn cabinet 1/2 wavelength at 35 Hz with a 10" driver has already been designed but the driver requires an Xmax of about 30mm for maximal performance. Manufacturers have not yet reached this potential that I am aware of but maybe somebody knows different??Regards to all
Rafaro
Edits: 02/03/16
I've not found 12-15mm xmax insufficient. A good horn will easily deliver 6dB more output than a direct radiator, so 15mm in a horn is the equivalent of 30mm in a direct radiator anyway. There's also the matter of throat distortion. There does come a point where the throat pressure is so high that all you'll get with more excursion is distortion, as well as the potential for shredding cones.
Good points Bill but easy enough to increase throat volume which will reduce distortion, pressure and cone shredding. And imagine what a 10-12"driver with 2-3 inches of Xmax will do in a 1/2 wavelength horn !!
Rafaro
When you increase throat area you lose sensitivity and increase ripple. An optimal horn for the LAB 12 has only 142 sq.cm. throat area. And as it would have 132dB maximum output to 22Hz I'd call that sufficient.
Hello Bill
When is "sufficient" enough for live sound?? For me, in live sound, speakers can never have too much output. When I noticed that a 1/2 wavelength sub woofer horn can put out up to 5 dB more than a similar 1/4 WL that was the end of 1/4 WL sub woofer horns for me. In my cab design it only meant adding two feet in depth but would require 4 or 5 of the 1/4 WL HORN cabs to match itīs output. (Please note that the output in subhorns increases about 5 dB when the freq reaches 1/2 WL). So excuse my compulsion for the ultimate efficiency it means less to carry but from a manufacturers point of view it also means less to sell.
Rafaro
Rafaro,
Let's do a "think back". Back in the day (late 60s to late 70s), it was cool to have a giant PA system, 'cause that was a badge of achievement. I'm talking about local/regional/national bands.
Then, someone got the idea that hauling a couple of truck-fulls of speakers (and setting them up), was stupid and a waste of money. Enter Meyer Sound. High output, high efficiency, low distortion. In 1980-81, I tried to promote Meyer Sound speakers. Could not sell 'em. They were expensive, and bands still wanted big over-sized P.A. systems, 'cause they were cheaper and cool.
:)
I have several Sonic Impact amps based on a Tripath chip. I took the amp to Klipsch headquarters in Indy and one of their engineers tested it. It put out 6 W/ch. with low distortion. He was impressed. Too bad Paul Klipsch didn't live long enough to see one. I certainly would have taken one to him in Hope when I was there in 1985 if it had even existed then.
It cost me 27 bucks and sounded really good. I put AA batteries in it, and plugged a Sony Walkman CD player into it and SOLD my 1977 Khorns with that demo in about 2 minutes. Blew the guy's mind, to put it mildly.
I still use one for curving drivers, since it's really portable and with a $20, 1A Radio Shack wall wart, it works great for that purpose.
... what Klipsch meant by "a *good* 5 watt amplifier"? How would he have defined *good* in this context?
~!
The Mind has No Firewall~ U.S. Army War College.
most of the amplifier manufacturers were engaged in 'power wars' such that the top-of-the-line amps of the day were sacrificing sound quality at low power levels in order to be able to publish higher wattage numbers in their marketing materials.
Again, just a guess.
As a person who prefers a few good watts, I stuck with all of the compromises one has to deal with when using high efficient speakers but I'll live. ;-)
... what Paul Klipsch wanted was a good sounding tube amp that was as quiet as a SS one. Low-noise performance must have seemed very important to him, or so I'd imagine.
Early SS amps were much noisier than tube, and Paul's quote made no mention of either tube or SS, probably because SS wasn't really in play yet. His comment was made when 10 to 30 watt amps were the most popular, and no one was interested in making a really high quality 5 watt amp, mainly because his were among the very few speakers that only needed 5 watts.
I read that his favorite amp was the Brooks sliding bias 2A3 PP amp.
Dave
Interesting, thanks. I did not know that early SS amps were that noisy.
See link
Don't know about 'best' but something like the FaitalPro 12RS1066, 12HP1060 and 12HP1030 (all Xmax 12.45mm) or the Eminence LAB12 (13mm) might fit your bill.
+1, the Lab 12 is pretty hard to beat. I can't imagine the need for more than 13mm xmax. Not needing more than that is the point of horns.
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