skepticism...
I was very interested in your post because I've been playing with mass loaded horns for a while, with different Fostex drivers.
What's interesting is that most fullrangers are categorised as no-bass (or very little). The box we designed makes the fullrange driver act as a fullrange unit (meaning 20 to 20k). The bass is unlike reflex or double chamber reflex, it's incredibly tight and fast and bouncy and strong.
I'm reticent to give specifics of the enclosure right now, because it will be introduced as a commercial product early 2007. Let's say that it's pretty close to a BLH (or expanding TL), terminated by a port. The length of the horn gives maximum pressure at both ends. Bass is pumped out of the vent while there's a strong back pressure at the driver's back. The cone don't move much.
The impedance curve doesnt look like anything else, it has two sets of peaks (saddle peaks), like two reflex boxes, wich would suggest two bass peaks, but measurements showed a pretty smooth vent output.
All in all, it sounds like a BLH with a very well matched invisible sub somewhere in the room!
I was very interested in your post because I've been playing with mass loaded horns for a while, with different Fostex drivers.
What's interesting is that most fullrangers are categorised as no-bass (or very little). The box we designed makes the fullrange driver act as a fullrange unit (meaning 20 to 20k). The bass is unlike reflex or double chamber reflex, it's incredibly tight and fast and bouncy and strong.
I'm reticent to give specifics of the enclosure right now, because it will be introduced as a commercial product early 2007. Let's say that it's pretty close to a BLH (or expanding TL), terminated by a port. The length of the horn gives maximum pressure at both ends. Bass is pumped out of the vent while there's a strong back pressure at the driver's back. The cone don't move much.
The impedance curve doesnt look like anything else, it has two sets of peaks (saddle peaks), like two reflex boxes, wich would suggest two bass peaks, but measurements showed a pretty smooth vent output.
All in all, it sounds like a BLH with a very well matched invisible sub somewhere in the room!
Perhaps?
Perhaps... I do not have the specifics of the design but Danley's measurements are also incredible, so that would make two sets of incredible measurements!
Similar results from dissimilar companies let me think that a lot of research can and should be done and that ultra hybrid designs can work very well indeed.
Perhaps... I do not have the specifics of the design but Danley's measurements are also incredible, so that would make two sets of incredible measurements!
Similar results from dissimilar companies let me think that a lot of research can and should be done and that ultra hybrid designs can work very well indeed.
Re: skepticism...
You tease!
OK. Finally time for me to get the latest versions of MJK's software.
The gauntlet has been thrown down. Gentlemen, start your worksheets. Let the simming begin!
robertG said:
You tease!OK. Finally time for me to get the latest versions of MJK's software.
The gauntlet has been thrown down. Gentlemen, start your worksheets. Let the simming begin!
Demo
If someone happens to be in Montreal during next FSI (Festival Son et Images) will be demoing the speakers.
Very impressive little boxes!
If someone happens to be in Montreal during next FSI (Festival Son et Images) will be demoing the speakers.
Very impressive little boxes!
FSI is usually at the end of march.
If you happen to be in Montreal anytime, the pair is alive and kicking and ready for demo!
If you happen to be in Montreal anytime, the pair is alive and kicking and ready for demo!
Don't assume mass loading is the only way forward to getting low bass. It's another tool, no more, one I like using, but I like other ways too.
Here's the projected 1/2 space response for a horn (BIB alternative) I'm developing for the FE207E. And yes, it will fit in most people's rooms. No details yet (sorry!) as I'm still working on the more detailed simulations: as you can see, the filter chamber and throat CSA needs a little work to get the response from 80-120Hz polished, but that won't take long. In-room it should be flat to about 25Hz at around 93db sensitivity, as this sim does not take into account room gain, or the effect of the reflectional boundary condition created by the floor enlarging one of the mouths.
Here's the projected 1/2 space response for a horn (BIB alternative) I'm developing for the FE207E. And yes, it will fit in most people's rooms. No details yet (sorry!) as I'm still working on the more detailed simulations: as you can see, the filter chamber and throat CSA needs a little work to get the response from 80-120Hz polished, but that won't take long. In-room it should be flat to about 25Hz at around 93db sensitivity, as this sim does not take into account room gain, or the effect of the reflectional boundary condition created by the floor enlarging one of the mouths.
Attachments
No assumption.
The idea was to bring the 108 to "real" full range in a small 1.5 sq. ft tower.
Small means no horn (in the classical horn application) and 20Hz free space (anechoïc) also means no horn...
I love BL horns for the quality of the bass. The hybrid box gave me the very same bass quality, with some infrasonics for the same price. Seems like a bargain.
This is not a sim, it's the real thing in real lab conditions, and in real world listening room, it's very convincing.
The idea was to bring the 108 to "real" full range in a small 1.5 sq. ft tower.
Small means no horn (in the classical horn application) and 20Hz free space (anechoïc) also means no horn...
I love BL horns for the quality of the bass. The hybrid box gave me the very same bass quality, with some infrasonics for the same price. Seems like a bargain.
This is not a sim, it's the real thing in real lab conditions, and in real world listening room, it's very convincing.
That wasn't a remark directed toward you Robert -it was thrown out generally. I've spend most of my time with MLTLs / ML TQWTs, so I'm quite an advocate of it, as you can imagine. I'll be interested to see your finished speaker / design etc. What sort of cone displacement are we seeing at 20Hz with these BTW?
Hey Scottmoose, no problemo!
Displacement: none at very low frequencies. Loud and sustained electrobass notes (you know, the kind of low-low bass athmosphere on some electro-lounge tracks) are reproduced with no cone movement, so loads of back pressure on cone.
Same on warble tone 20 to 50Hz.
More displacement when enclosure is not loading driver as much, in the 100 to 200Hz, but nothing alarming (no more than same driver in BLH)
No discernable cone break up, but further laser refraction analysis will tell for sure..
Displacement: none at very low frequencies. Loud and sustained electrobass notes (you know, the kind of low-low bass athmosphere on some electro-lounge tracks) are reproduced with no cone movement, so loads of back pressure on cone.
Same on warble tone 20 to 50Hz.
More displacement when enclosure is not loading driver as much, in the 100 to 200Hz, but nothing alarming (no more than same driver in BLH)
No discernable cone break up, but further laser refraction analysis will tell for sure..
Sorry RobertG -- but this is starting to sound like marketing mumbo jumbo
Can I model this in MJK's worksheets?
If not, why not (without giving away the fahhhm)?
Can I model this in MJK's worksheets?
If not, why not (without giving away the fahhhm)?
I'm not familiar with MJK worksheets, you should ask MJK himself.
DIY is not about marketing and I do not intend to sell anything to anyone here.
DIY is not about marketing and I do not intend to sell anything to anyone here.
interesting reading at 6 moons
mass loaded horn
http://www.sixmoons.com/audioreviews/atelier/firsthorn_2.html
unmodified horn reveiw
http://www.sixmoons.com/audioreviews/atelier/firsthorn.html
Regards Philip
mass loaded horn
http://www.sixmoons.com/audioreviews/atelier/firsthorn_2.html
unmodified horn reveiw
http://www.sixmoons.com/audioreviews/atelier/firsthorn.html
Regards Philip
robertG said:
Exactly MY point.
Your certainly not helping anyone to DIY design / build one.
ANY hints?
qi said:
Is the driver offset from the top of the enclosure?
Is it an expanding tapered folded pipe?
Is the port undersized (mass-loaded)?
footstony said:
I believe those are one of (2 of?) Roberts.
Of more interest is his Concerti, http://www.6moons.com/audioreviews/gemmeaudio/108.html, which looks to be an all out assault on the Fostex recommended horn/TL.
dave
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