Hi Mark,
Thanks. I like to stay w/ ~ Xmax for right now, but I realize there is a bit of excursion left.
Have you found any drivers that are price competitive (or even close) w/ the SI HT18 for a horn or TH that goes that low?
Regards,
Thanks. I like to stay w/ ~ Xmax for right now, but I realize there is a bit of excursion left.
Have you found any drivers that are price competitive (or even close) w/ the SI HT18 for a horn or TH that goes that low?
Regards,
Nope pretty much rules bang for the buck.
As for tapped horns, well I have made one, assisted on the design of a couple others. Don't like the sound signature. They add a lot that is not there is the first place. Many people like the sound. I can't stand them. Reminds to much of the 80's and bandpass enclosures.
The resulting sound of each is pretty close. To many harmonics that are added in due to the double tuning.
And I can count on one hand the number of designs I have seen that have more than 4 db of gain over an equivalent ported enclosure. The one I did had 7 db of gain. Tried it against three other enclosures in a shoot out. All gain matched and all used the same drivers. Was an interesting experiment.
That's funny, because I don't aim for anywhere near that amount of gain. IMO THs are similar to bandpass alignments, and bandpass alignments also sound pretty awful when you engineer them with too much gain. One-note wonders. The last one I did, POC4, had just over 3dB of gain, and that's mainly because I was actually trying to keep the box size down 🙂.
When you do a front loaded horn 7 db is rather easy, squeaking past that is a little difficult.
I played to much music to not know what I'm missing in a low efficiency system. That's principally why I design high efficiency products. I find them much more life like.
I played to much music to not know what I'm missing in a low efficiency system. That's principally why I design high efficiency products. I find them much more life like.
Can't beat the dynamics of a high-efficiency system, that's true 🙂.
That's why if I'm going for high-efficiency with a TH, I start off with a driver that's already pretty efficient, rather than trying to make the TH alignment add a lot of efficiency. POC4 uses the 18TBX100, which is rated at 97dB/1W/1M, and POC4's alignment brings the efficiency up to 100dB/1W/1M in the passband. As that passband extends down to just below 35 Hz, I can live with that 🙂.
In comparison, some have used the Eminence LAB 12 in a TH. At its 89dB/1W/1M rating, it's not a driver I'd choose for a TH, at least not for pro audio use.
THs aren't real horns anyway. More like TLs than anything else.
Properly tuned they are a dual resonant gain system. But like you mentioned Grabbing the right driver gets you some interesting results. You get a high and a low resonant peak and the harmonics fill in between.
Yes, in that respect they're more like 6th order BP alignments than TLs. However, I've built 6th order BP alignments though, and THs don't sound like them, particularly the ones I've built or modified with the aim of eliminating the notch in the FR just above the passband.
From what I've learned between POC1 and POC4, I now have a pretty good idea what to aim for in a TH design, and it's interesting how similar some of the "guidelines" are to those for bandpass alignments.
I watched your posts.
You do have a good handle on what you are up against. They were pretty well thought out designs.
You do have a good handle on what you are up against. They were pretty well thought out designs.
Do I hear advocacy of low gain complicated multi-resonant enclosures???
Have we come full circle to a sealed box with all the advantages of one? Or a leaky box?
Ben
Have we come full circle to a sealed box with all the advantages of one? Or a leaky box?
Ben
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I come from a reference point of what a good horn can accomplish.
A sealed box with a very high BL driver and a couple of kilowatts are the closest thing I have heard to a good horn.
Few people are working with that type of a driver. It requires EQ and a understanding of the sizing requirements in a sealed enclosure.
The other thing I have learned that dumping power ( I have worked with 24 kilowatt systems) into a driver, even a very capable one, does not equate the inherent efficiency and seemingly instantaneous dynamics available in a true horn.
So if you need to be practical, build the best sealed box you can afford. Do your homework. And you will end up with a pretty good clean low end system.
Right. As long as we're shaking heavy cones to make sound, only a true horn provides the impedance match to work properly. And, as you say, second best is....
Ben
Just a reminder: the OP is looking for a solution to *produce*, not *reproduce" music. Some of the desirable attributes we look for in a "hi-fi" system don't really apply here.
I'll bet that organ pipes are pretty high-Q devices... 🙂
Again, Brian says smart things.
But I think you are wrong in this sense. The speaker is reproducing the signal created by the tone generator (or whatever you call the thingy in electric organs today). So it should never have characteristics of its own but rather be able to neutrally reproduce whatever it is called on to play.
An exception would be if you had a purpose-built single-pipe speaker and, of course, a rank of these.
While picturing that lovely room of speakers in your mind, I'll just point out that a tone generator "imitating" a single pedal is not generating a sine wave at 16 Hz but a whole bunch of stuff that people kind of feel is reminiscent of a real big pipe (probably not bothering to actually put out much at 16 Hz which would be largely wasted).
I'd guess Brian would say an electric guitar is contrary illustration. But then some of us don't think of any electric instrument* as musical largely BECAUSE they are bounded by the limitations of speakers.
So you can figure if I am celebrating this week the 50th anniversary if Bob Dylan going electric at Newport.
Ben
*Theramin excepted
Ben
Yes some are an interesting blend.
The open flue pipes are pretty close to a decent sine wave.
A stopped pipe literally has a plug on the end. Very rich in even order harmonics.
The reeds are rich in harmonics.
The mixtures, many pipes sound for each key pressed, and are tuned apart in odd note spacings. Thirds, fifths, sevenths, and so on.
Yes there are some pretty tame and pretty wild sounds to reproduce.
And reproduce is the key. Every good musician knows what his instrument should sound like.
When it comes out wrong it is just plain wrong.
I can seriously think of a few organ stopps that would sound awesome through a tapped horn. A nice tubby diapason, large scale unterstaz, Bourdon, any of the stopped pipes like the gamba. They would benefit from the richness in harmonics added.
And a few with bite and really fast attack like the big reeds, trumpets, bombardes, faggots, that will sound plain wierd.
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Plausible. But do you have any reason to think the array of harmonics from a flue pipe would resemble those from a TH which produces an unmusical array harmonics*?
BTW, I think it might OK to tune some enlosure for 16 Hz, provided it wasn't too high Q or dirty.
Ben
*OK for the Green Bay Packers stadium but that can really destroy your stereo image even in pairs
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Hi Y'all,
Interesting discussion, just some thoughts:
I tend to like the sealed box sound too, but it just looses too much in the very bottom end in this application, and a horn just looks too large. The Gjallarhorn is 24x45x45", and uses a LMS Ultra 5400 driver (don't know if that one is still available anywhere, or for how much $1000.--?).
One aspect that is not discussed frequently is the power handling, in any of the resonant systems the cone comes almost to a standstill @ one or more points in the pass-band, the overhanging ends of the coice coil have a tendency to get hot rapidly if the coil/cone is not moving. The sealed box does not have that problem. The TH places the back of the driver (coil/magnet) close to the open end of the duct, that is bound to help cooling. It's always something...
There have been a few discussion comparing the TH to the T-TQWT, and member bjorno has been the main advocate of the T-TQWT, here is one link: http://www.diyaudio.com/forums/subwoofers/198056-th-t-tqwp-2.html see: Post #20, bjorno on sound quality. That statement intrigues me, so my next subwoofer will definitely be a T-TQWT just to try it out, and I like the version w/ the driver app. in the middle of the inverted horn (in Hornresp: L12+L34 about equal to L23).
BR and T-TQWT have close to the same SPL level in the simulations, but the output duct cross-section of the T-TQWT is much bigger than of the BR. So in real life I'd expect the T-TQWT to have only negligible port compression, and the BR tuned to app. 16Hz could loose a lot of output right were it's need in this application owing to the fact that all the output in the pipe fundamental frequency range comes from the port (cone is not moving). This can be helped by using a larger port as in the big data-bass DIY-BR w/ power port, which results in a larger box...
I found another driver that looks promising: the Fi-Car Audio SSD18 $274.--
SSD18 - Fi Car Audio Store
It sims fine in a BR or a T-TQWT @ Vint=354L, about the same as the SI HT18.
Regards,
Interesting discussion, just some thoughts:
I tend to like the sealed box sound too, but it just looses too much in the very bottom end in this application, and a horn just looks too large. The Gjallarhorn is 24x45x45", and uses a LMS Ultra 5400 driver (don't know if that one is still available anywhere, or for how much $1000.--?).
One aspect that is not discussed frequently is the power handling, in any of the resonant systems the cone comes almost to a standstill @ one or more points in the pass-band, the overhanging ends of the coice coil have a tendency to get hot rapidly if the coil/cone is not moving. The sealed box does not have that problem. The TH places the back of the driver (coil/magnet) close to the open end of the duct, that is bound to help cooling. It's always something...
There have been a few discussion comparing the TH to the T-TQWT, and member bjorno has been the main advocate of the T-TQWT, here is one link: http://www.diyaudio.com/forums/subwoofers/198056-th-t-tqwp-2.html see: Post #20, bjorno on sound quality. That statement intrigues me, so my next subwoofer will definitely be a T-TQWT just to try it out, and I like the version w/ the driver app. in the middle of the inverted horn (in Hornresp: L12+L34 about equal to L23).
BR and T-TQWT have close to the same SPL level in the simulations, but the output duct cross-section of the T-TQWT is much bigger than of the BR. So in real life I'd expect the T-TQWT to have only negligible port compression, and the BR tuned to app. 16Hz could loose a lot of output right were it's need in this application owing to the fact that all the output in the pipe fundamental frequency range comes from the port (cone is not moving). This can be helped by using a larger port as in the big data-bass DIY-BR w/ power port, which results in a larger box...
I found another driver that looks promising: the Fi-Car Audio SSD18 $274.--
SSD18 - Fi Car Audio Store
It sims fine in a BR or a T-TQWT @ Vint=354L, about the same as the SI HT18.
Regards,
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Oliver, I have to agree with you.
Any decent front loaded horn will not fit without there being a complete refold. And take up as much room as all the enclosures that are currently there.
Being practical is what is key here. And your tapped horn designs are much more practical.
Any decent front loaded horn will not fit without there being a complete refold. And take up as much room as all the enclosures that are currently there.
Being practical is what is key here. And your tapped horn designs are much more practical.
Oliver.
You want to knock around some ideas to tweak your tapped horn design?
I don't like em, but I have designed them. And ones with appreciably more gain to boot!
It might require a driver substitution. Something along the lines of a B&C 18NW100 or a FaitalPro 18HP1020.
Bigger BL motor.
A little more money, less excursion, but excursion is not all that in the first place. We could optimize this tapped horn to be a first octave performer only. (16 to 32 hetz or so) Narrow bandwidth and high efficiency.
You want to knock around some ideas to tweak your tapped horn design?
I don't like em, but I have designed them. And ones with appreciably more gain to boot!
It might require a driver substitution. Something along the lines of a B&C 18NW100 or a FaitalPro 18HP1020.
Bigger BL motor.
A little more money, less excursion, but excursion is not all that in the first place. We could optimize this tapped horn to be a first octave performer only. (16 to 32 hetz or so) Narrow bandwidth and high efficiency.
If you (and everybody) really find the answer to the question, "Why does my sim always say bottom end is sacrificed?" you might be surprised.
I suspect few readers in this thread will be motivated by any post of mine. So here is a hint question, "Why do sims generally make sealed boxes smaller than ported boxes?"
Ben
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It depends on what you are using to simulate your designs.
A few free programs are flawed. WinISD is one and Bagby's woofer simulation program is another that spits out incorrect information.
A few free ones that are great:
Hornresp. King among simulation programs. And has been updated at a rate I can't keep up with. If you can't simulate it in this program you are in trouble.
Unibox. For conventional design work is about the best for the simple stuff.
And there are a few that are really easy, and accurate enough.
Boxnotes is a great example.
What is missing and I think Ben is alluding to this is the transfer function between the room and the driver enclosure system. A few of the programs can incorporate this. And as Ben has measured there are fairly simple systems that in the right room, with the right placement position can really reproduce the low end. With modest drivers none the less.
Sims are not worth much if you don't know how they are going to perform in real life.
And computers are only as useful as the information in and out. Not blaming the designers, but sometimes the programmers for overlooking errors in the output.
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