Hi Nigel,
how are you?
This subwoofer was intended to be just an experience and I'm still evaluating it. What happened here was a kind of magic (synergy) with the Fonkens and my room. Two main reasons contributed to that:
- The room is small (150 ft2) with good acoustic treatment for bass.
- It is being used for music only.
If your room is bigger and you will use for movies, maybe the Donald is not suitable for you. It has 7mm linear excursion and 11mm mechanical limits. If you put the Donald into a bigger room and turn up the low gain to feel the movies explosions, there is a true damage risk.
About the behavior above 100Hz, when we model the speaker and do simulations, we don't consider the room influence on that. When we measure the real response of the speaker with the microphone at 5cm of the mouth, we are minimizing the room influence.
Then, when we measure the room response (speaker at practical position and mic at listening pos.) we are measuring how the subwoofer behaves in your room acoustics. And the response we get is completely different.
In the specific case of the Donald (nobody asked why I named as "Donald"?
) the simulations and mouth measurements confirmed extreme non-linearity above 100Hz, but the room response absorbed that and both measurements and listening proved that. If this non-linearity was harmful I would probably need a 4th order cross-over to minimize that, or a digital EQ.
The Fonkens are not x-overed. After some tests I realized that, here, the fonken plays better with not filtering. They play here above 90-100Hz and I set the subwoofer in a point that best integrates with the mains. I will try adding a capacitor (for 1st order filter) to the fonkens to relief them of the signals under ~80Hz. But I need to say something... these Fonkens with 127EnABL + Planet 10 trifoil are special. True hi-fi speakers.
We can try to find a Brazilian driver, maybe 8" or 10" that is more suitable for Home Theater and safer for more SPL. What do you think?
thanks
HF
how are you?
This subwoofer was intended to be just an experience and I'm still evaluating it. What happened here was a kind of magic (synergy) with the Fonkens and my room. Two main reasons contributed to that:
- The room is small (150 ft2) with good acoustic treatment for bass.
- It is being used for music only.
If your room is bigger and you will use for movies, maybe the Donald is not suitable for you. It has 7mm linear excursion and 11mm mechanical limits. If you put the Donald into a bigger room and turn up the low gain to feel the movies explosions, there is a true damage risk.
About the behavior above 100Hz, when we model the speaker and do simulations, we don't consider the room influence on that. When we measure the real response of the speaker with the microphone at 5cm of the mouth, we are minimizing the room influence.
Then, when we measure the room response (speaker at practical position and mic at listening pos.) we are measuring how the subwoofer behaves in your room acoustics. And the response we get is completely different.
In the specific case of the Donald (nobody asked why I named as "Donald"?
) the simulations and mouth measurements confirmed extreme non-linearity above 100Hz, but the room response absorbed that and both measurements and listening proved that. If this non-linearity was harmful I would probably need a 4th order cross-over to minimize that, or a digital EQ.The Fonkens are not x-overed. After some tests I realized that, here, the fonken plays better with not filtering. They play here above 90-100Hz and I set the subwoofer in a point that best integrates with the mains. I will try adding a capacitor (for 1st order filter) to the fonkens to relief them of the signals under ~80Hz. But I need to say something... these Fonkens with 127EnABL + Planet 10 trifoil are special. True hi-fi speakers.
We can try to find a Brazilian driver, maybe 8" or 10" that is more suitable for Home Theater and safer for more SPL. What do you think?
thanks
HF
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Hi Highef,
Actually, when I said I was impressed I wasn't only thinking of my immediate needs - it was more of a general remark...
Speaking personally, at this point I am only interested in systems for music. I understand home theatre is a different issue, and many people care about this, but for the time being not me... I want to listen to orchestras, string quartets and jazz combos, and am not concerned about earthquakes, explosions or car crashes...
The photograph of your listening room is maybe misleading; it looks bigger than 150ft2. And how high are the ceilings?
Well, that's a good question...
I like the 127Es too, although I haven't tried the EnABLed ones. I haven't tried them in a Fonken cabinet, either...
I have another thread running about Brazilian (sub)woofer drivers, although I confess I let it lapse a little since I thought a friend could bring a pair of Peerless subs from the US for me. Unfortunately he can't, so I'll have to get moving on that again; I am sure if the diy community here puts their heads together we can find Brazilian drivers that will substitute the US anmd European imports, at least mostly. This is one of the reasons I find your work here so fascinating; if this Akron driver is so good in this horn, it is likely good in other boxes too, and may be more interesting than I thought, even if it may be a little small for big rooms/spaces. (I am thinking: two-way standrd box, sub for the office... lots of possibilities...)
Um abraco
Nigel
Actually, when I said I was impressed I wasn't only thinking of my immediate needs - it was more of a general remark...
Speaking personally, at this point I am only interested in systems for music. I understand home theatre is a different issue, and many people care about this, but for the time being not me... I want to listen to orchestras, string quartets and jazz combos, and am not concerned about earthquakes, explosions or car crashes...
The photograph of your listening room is maybe misleading; it looks bigger than 150ft2. And how high are the ceilings?
In the specific case of the Donald (nobody asked why I named as "Donald"?
Well, that's a good question...
I like the 127Es too, although I haven't tried the EnABLed ones. I haven't tried them in a Fonken cabinet, either...
I have another thread running about Brazilian (sub)woofer drivers, although I confess I let it lapse a little since I thought a friend could bring a pair of Peerless subs from the US for me. Unfortunately he can't, so I'll have to get moving on that again; I am sure if the diy community here puts their heads together we can find Brazilian drivers that will substitute the US anmd European imports, at least mostly. This is one of the reasons I find your work here so fascinating; if this Akron driver is so good in this horn, it is likely good in other boxes too, and may be more interesting than I thought, even if it may be a little small for big rooms/spaces. (I am thinking: two-way standrd box, sub for the office... lots of possibilities...)
Um abraco
Nigel
Nigel,
did you know that the Akron KB6 is manufactured by Keybass as OEM following a Paulo Ramos (Akron owner) design? After the industrial process provided by keybass, Akron do some mods to give special features to the driver.
If I'm not wrong, they are planning to release a 8" version. I think you should contact Paulo Ramos and ask him for driver suggestions.
regards
HF
did you know that the Akron KB6 is manufactured by Keybass as OEM following a Paulo Ramos (Akron owner) design? After the industrial process provided by keybass, Akron do some mods to give special features to the driver.
If I'm not wrong, they are planning to release a 8" version. I think you should contact Paulo Ramos and ask him for driver suggestions.
regards
HF
Ohhhh!! An 8" version of this driver might meet my needs very well indeed.... (although I wasreally thinking of 10" or so...) I'll try to contact Paulo Ramos through the Akron website...
Thanks for the info.
Um abraco
Nigel
Hey HF,
This sorta covers what I'm looking for, mainly a music sub but I really want something I can drive to provide the thumps for movies. May I ask if we can close the opening/slot load and what effect that has on output levels, frequency response? I am new to the the TH concept, I am looking for a sub I can build for stereo sub use, and this looks good size wise, though I am still learning about how these respond in room. Mine isn't flash.
I was also thinking of using the CSS SDX10 to provide a little extra output. Was also thinkin to use a sealed enclosure. Can these be combined? i.e. small sealed enclosure at the bottom of the speaker, with sub front mounted or downfiring with the TH above with the vent as you have it in the photo's?
Am sure I'll come up with other questions that neewbie's doooo!!
Thanks, very cool to see!!!
This sorta covers what I'm looking for, mainly a music sub but I really want something I can drive to provide the thumps for movies. May I ask if we can close the opening/slot load and what effect that has on output levels, frequency response? I am new to the the TH concept, I am looking for a sub I can build for stereo sub use, and this looks good size wise, though I am still learning about how these respond in room. Mine isn't flash.
I was also thinking of using the CSS SDX10 to provide a little extra output. Was also thinkin to use a sealed enclosure. Can these be combined? i.e. small sealed enclosure at the bottom of the speaker, with sub front mounted or downfiring with the TH above with the vent as you have it in the photo's?
Am sure I'll come up with other questions that neewbie's doooo!!
Thanks, very cool to see!!!
Hi PET,
I'm not sure if I understand what you mean. The Donald (as the other THs) has only one port: The mouth. If we close them... no sound, right?
I don't suggest you combining subwoofers. If you build the SDX10 sealed it will be nice, you don't need more than that.
The photo I posted before shows the subwoofer in a bad place. See this new picture, the Donald is under the curtain with the mouth upwards. This is a good position for it in my specific case.
thanks
HF
Hi Siqdiz,
This xover was made by a friend. It has sub-sonic filter, cut frequency controller and volume controller.
About the pre-amp, yes. It controls both the tube and sub SS amplifier at the same time. If I turn up the pre-amp volume, both main speaker and sub will be affected. The subwoofer xover has also the volume control so I can find the best volume point relative to the main speakers. Once it is set, I don't touch it anymore.
regards
HF
This xover was made by a friend. It has sub-sonic filter, cut frequency controller and volume controller.
About the pre-amp, yes. It controls both the tube and sub SS amplifier at the same time. If I turn up the pre-amp volume, both main speaker and sub will be affected. The subwoofer xover has also the volume control so I can find the best volume point relative to the main speakers. Once it is set, I don't touch it anymore.
regards
HF
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