The problem I have with the Augie is the low efficiency, 88 dB/W/m. Put this driver in a relatively narrow baffle and it will be into the low 80 dB's by 50 Hz, the floor reflection will help but not that much. Now you try and pair it with a relatively efficient full range driver, I am assuming the Feastrex is perhaps 95 dB/W/m, and you have a huge SPL mismatch. The only solution is to put a ton of power into the Augie to prop up the SPL which leads to its own set of problems.
Without active biamping you end up with light weight bass response from the system. With active biamping and tons of power into the Augie I would be concerned about thermal compression and reaching Xmax quickly which would compromise the system bass performance. Those are my concerns based on running some simulations pairing the Augie with a couple of other full range drivers.
I think the real intent of the Augie was for it to be paired with the Silver Iris running full range and thus just adding extra bass output to the Silver Iris' bass response. You then roll the Augie out at 100 Hz or so, it augments the bass output from the Silver Iris hence its name. If used in that way it probably works well, but as a stand alone bass driver paired with a high efficiency full range driver I think it is not efficient enough to do the job.
To be able to recommend a woofer to mate with the Feastrex would require the T/S parameters for the Feastrex driver. I don't know what the measured T/S parameters are for the Feastrex, I have not searched the Internet to see if they are available.
Without active biamping you end up with light weight bass response from the system. With active biamping and tons of power into the Augie I would be concerned about thermal compression and reaching Xmax quickly which would compromise the system bass performance. Those are my concerns based on running some simulations pairing the Augie with a couple of other full range drivers.
I think the real intent of the Augie was for it to be paired with the Silver Iris running full range and thus just adding extra bass output to the Silver Iris' bass response. You then roll the Augie out at 100 Hz or so, it augments the bass output from the Silver Iris hence its name. If used in that way it probably works well, but as a stand alone bass driver paired with a high efficiency full range driver I think it is not efficient enough to do the job.
To be able to recommend a woofer to mate with the Feastrex would require the T/S parameters for the Feastrex driver. I don't know what the measured T/S parameters are for the Feastrex, I have not searched the Internet to see if they are available.
OK, so they are 92.2 dB/W/m which probably means two bass drivers to achieve a combined 98 to 100 dB/W/m efficiency. The high fs of 108 Hz is a bit of a problem if a passive crosover is used in the 200 to 400 Hz range. If it was me, and it is not since they are too expensive for my budget, I would probably start with a pair of my old reliable Eminence Alpha 15A woofers and design away using MathCad simulations.
I am about to try an open baffle for D5nf, so this thread is timely! Thanks Gents! I had a pair of Augies on my Christmas list, but I just put a hold on them.
Joe, your baffles look good! Nice job.
Dick Olsher's article about the Augie says that the SPL of the two drivers balance out because of the impedance difference between the two drivers. In fact in an email to me he said that he had to pad down the woofer with a shunt resistor of 25ohms. He suggests even with active crossover, as I intend to use, the shunt should be retained.
He thinks the crossover point of his OB2 was about 250Hz. I don't know how to calculate the exact crossover freq from his network schema.
I looked up the Eminence 15A. It's Qts of 1.36 is higher than Augie's 0.92, so to my limited understanding the 15A should be louder than the Augie, which supposedly already needs padding when played with D5nf.
My Legacy speakers play down to 20Hz and I want at least 30Hz from these open baffle speakers. The 15A bottoms at 46Hz, but Augies will play lower, resonance at 27Hz. Peerless 830500 XLS 12" woofer Qts is 0.20, and the 10" version is used in Orion open baffle speaker, in a H-frame OB enclosure. The long excursion of the Peerless XLS or even the XXLS will allow significant bass boosting by EQ if necessary to get me flat at 20Hz, 100dB. OUCH that hurts!!! I do like my organ music on the loud side....... hehehe
I licensed Martin's software to help design these OBs, but as you can tell I know jack, but looking forward to learning something along the way.
Rich
Joe, your baffles look good! Nice job.
Dick Olsher's article about the Augie says that the SPL of the two drivers balance out because of the impedance difference between the two drivers. In fact in an email to me he said that he had to pad down the woofer with a shunt resistor of 25ohms. He suggests even with active crossover, as I intend to use, the shunt should be retained.
He thinks the crossover point of his OB2 was about 250Hz. I don't know how to calculate the exact crossover freq from his network schema.
I looked up the Eminence 15A. It's Qts of 1.36 is higher than Augie's 0.92, so to my limited understanding the 15A should be louder than the Augie, which supposedly already needs padding when played with D5nf.
My Legacy speakers play down to 20Hz and I want at least 30Hz from these open baffle speakers. The 15A bottoms at 46Hz, but Augies will play lower, resonance at 27Hz. Peerless 830500 XLS 12" woofer Qts is 0.20, and the 10" version is used in Orion open baffle speaker, in a H-frame OB enclosure. The long excursion of the Peerless XLS or even the XXLS will allow significant bass boosting by EQ if necessary to get me flat at 20Hz, 100dB. OUCH that hurts!!! I do like my organ music on the loud side....... hehehe
I licensed Martin's software to help design these OBs, but as you can tell I know jack, but looking forward to learning something along the way.
Rich
Madisound has a driver for sub duty to augment full rangers and it's made by Eminence.. http://www.madisound.com/catalog/product_info.php?manufacterers_id=127&products_id=1768
But if one can afford the Feastrex then how about the StudioBass by AER... Looks Sweeeet!!!! http://www.aer-loudspeaker.com/html/studiobass.html Dave
But if one can afford the Feastrex then how about the StudioBass by AER... Looks Sweeeet!!!! http://www.aer-loudspeaker.com/html/studiobass.html Dave
AER Studiobass, basic T/S parameters.
Re = 18ohms
Qe = 0.29
Qm = 1.3
Qt = 0.24
Fs = 21Hz
Bl = 1.8 Tesla
Vas = 360 litres.
Q is a bit low for use on a flat OB IMO, unless multiple units or Eq is used.
T/S parameters for all the drivers are available on the AER site, but you've got to go hunting a bit: go to the German section, Klangwelten (literally 'Sound Worlds' IIRC) & select the appropriate unit. They're also to be found here: http://www.tonianlabs.com/aer.html
Re = 18ohms
Qe = 0.29
Qm = 1.3
Qt = 0.24
Fs = 21Hz
Bl = 1.8 Tesla
Vas = 360 litres.
Q is a bit low for use on a flat OB IMO, unless multiple units or Eq is used.
T/S parameters for all the drivers are available on the AER site, but you've got to go hunting a bit: go to the German section, Klangwelten (literally 'Sound Worlds' IIRC) & select the appropriate unit. They're also to be found here: http://www.tonianlabs.com/aer.html
tinitus said:
A local has one of those (or similar -- it is the field coil) and he raves about it (i always take anything this person says with a grain of salt)
One has too make sure if looking at an AER that one is getting a real AER as opposed to the counterfit... (i'm still not clear in my mind which URL takes you to which)
dave
Richidoo said:
Richidoo might know Jack but he's my best friend !(Jack that is) Consequently your comments on this matter, Martin. Scott, et al are very helpful. One day soon I'm going to try making some OBs. If I like them then Feastrex drivers might be the ultimate implementation. In the meantime I've bought some . . . . oops nearly went off topic
Anyway, if I do eventually get the Feastrex, my plan would be for bass duties to be handled by my Velodyne DD12.
planet10 said:
The Genuine AER -- the one to make sure you are getting -- is under the direction of Filip Keller.
The Knock-Off "AER" -- the one people are being advised to avoid, or at least to recognize as being a different speaker -- is under the direction of Ins Adler.
Unfortunately, both seem to be based in Stuttgart.
Personally, even if Adler's knock-off product was decent as a speaker, I would never knowingly buy them because I'm offended by the ethics of someone who would take a name that was already in use, and still in use by a living manufacturer, and produce similar-looking copies under the same name. Even assuming it was all (strictly speaking) legal, that does not make it ethical. Not only is it a foul act against the maker of the genuine product (in this case Filip Keller), it is a foul act against end users in the marketplace. I'm not even suggesting the knock-off products are necessarily inferior (although I expect that they are). The point is, they must inevitably be different, and therefore they should differentiated in their naming and logo marks as well, to prevent confusion in the marketplace. Unless you use identical components and identical manufacturing methods -- down to the tiniest detail -- the sound will be different. To market them under the same name is a travesty. For the audiophile contemplating a purchase, it is a choice between a) the artist who was recently given a crash course in the realities of modern business or b) the "sharp" (?) businessperson who wouldn't recognize true art if it bit her on the nose . . .
(End of rant)
Sorry, I know the above was off the topic of this thread, but I think this needs to be pointed out whenever the subject of these two drivers comes up. I'll get back on topic with my next post . . .
-- Chris
Here are some pics of the Feastrex Dimension 9x enclosure. Shown is the Dimension 9e (hence the power connector with diode). In the photo showing the speaker terminals from the inside of the box, the internal speaker wiring has not yet been attached to the terminals. The toggle switch is to switch the polarity of the field coil. Because the polarity of the signal input can also be inverted, a total of four combinations can be tried. I have not confirmed this, but apparently the different combinations sound different, so in addition to varying the field coil voltage, this becomes another factor for the DIYer to play with. The enclosure would also be appropriate for the permanent magnet versions of the 9-inch driver.
A box like this would be easy enough to build -- I estimate the internal volume is just a little shy of 120 liters and probably if the volume was in that general neighborhood, good results could be obtained. Mr. Teramoto told me he thinks better results are obtained by making the enclosure shallower and wider rather than narrower and deeper -- something to keep in mind if one is going to build a bass reflex enclosure for any of the Feastrex drivers.
-- Chris
A box like this would be easy enough to build -- I estimate the internal volume is just a little shy of 120 liters and probably if the volume was in that general neighborhood, good results could be obtained. Mr. Teramoto told me he thinks better results are obtained by making the enclosure shallower and wider rather than narrower and deeper -- something to keep in mind if one is going to build a bass reflex enclosure for any of the Feastrex drivers.
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-- Chris
Chris,
Could you give some dimensions of the cabinet at all (by PM if you prefer)? I ask because I have a theory that I'd like to confirm.
Re AER guys, as Chris notes, the real ones are Filip Keller's. You find them at www.aer-loudspeaker.com or www.aeroriginal.com
The fakes, which are to be avoided, are at www.aer-loudspeakers.com
Could you give some dimensions of the cabinet at all (by PM if you prefer)? I ask because I have a theory that I'd like to confirm.
Re AER guys, as Chris notes, the real ones are Filip Keller's. You find them at www.aer-loudspeaker.com or www.aeroriginal.com
The fakes, which are to be avoided, are at www.aer-loudspeakers.com
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