HI,
Of course, I read the other threads before posting, but I didn't find exactly what I'm looking for. I plan to build enclosures for my new drivers that have a VERY low Qts.
My listening room is 16' x 14 'x 9' and yes, I can place the speakers in the corners. I mostly listening to jazz and classical.
I'm open to any suggestions (BIB, BLH, TQWT, etc.) and I don't really care about the size or the look...
The spec. :
Driver : Audio Nirvana Super 8 Cast Frame
sensit. : 97.3 db
equivalent diaghram radius : 88 mm
equivalent mass : 10.023
magnet weight : 1400 g
net weight : 3690 g
Fs : 44.63
Re : 7.2
Mms : 11.748 g
BL : 11.84 TM
Qts : 0.162
Qms : 3.836
Qes : 0.169
Vas : 66.495 ltre
Xmax : 1.0 mm
no : 3.379 %
Thanks a lot !
Of course, I read the other threads before posting, but I didn't find exactly what I'm looking for. I plan to build enclosures for my new drivers that have a VERY low Qts.
My listening room is 16' x 14 'x 9' and yes, I can place the speakers in the corners. I mostly listening to jazz and classical.
I'm open to any suggestions (BIB, BLH, TQWT, etc.) and I don't really care about the size or the look...
The spec. :
Driver : Audio Nirvana Super 8 Cast Frame
sensit. : 97.3 db
equivalent diaghram radius : 88 mm
equivalent mass : 10.023
magnet weight : 1400 g
net weight : 3690 g
Fs : 44.63
Re : 7.2
Mms : 11.748 g
BL : 11.84 TM
Qts : 0.162
Qms : 3.836
Qes : 0.169
Vas : 66.495 ltre
Xmax : 1.0 mm
no : 3.379 %
Thanks a lot !
Thanks for your reply. If I go with BLH, do you have some particular suggestions?
I'd 2nd the use of a back-horn for this unit, but you'll need some help from the amplifier (viz. a reasonably high output impedance), or Eq of xyz kind, be it passive, active, or high resistance speaker wire, since if the advertised spec. is correct, the driver's -3dB mass corner will be at 528.16Hz -higher than any back-load can be practically run.
measure your t/s specs exactly for your units first and make sure you're actually dealing with those specs first!
Measuring Frequency Response Using ARTA
Screams Onken box to me.. 
I'm running Onkens with low qts drivers - namely the Iconic 165-8G which is essentially similar to the GPA 515-8G or late Altec 515..
Xmax seems very limited which IMO would mean that you should not be going for the ultimate in bass extension with these drivers and should probably cross to something else around 100Hz or so. Certainly would measure the TS params as suggested in a previous post, and probably try a simulation in a tool that will give you your xmax limitations..
I'm running Onkens with low qts drivers - namely the Iconic 165-8G which is essentially similar to the GPA 515-8G or late Altec 515..Xmax seems very limited which IMO would mean that you should not be going for the ultimate in bass extension with these drivers and should probably cross to something else around 100Hz or so. Certainly would measure the TS params as suggested in a previous post, and probably try a simulation in a tool that will give you your xmax limitations..
Thanks Scott for those useful informations. I already start to take a look at some BLH design, but it meens a lot of wood working. I would have more time to realize this kind of project in 1 or 2 mounts. Till this moment, I would like to do something more simple. I talk to a guy who made BIB enclosure to use with a pair of AN super 8 (regular, not cast frame). He did it 5 years ago, was very satisfied, but for some reasons, didn't keep them. Here the thread :
http://www.diyaudio.com/forums/full-range/116697-giant-bib-audio-nirvana-super-8-a.html
He also told me that you gave him some advices and measures. I'm not asking you to do the job for me
, but I would be very happy to have your opinion. Do you think it worts it do the experiment of using AN in BIB? I already made some calculations with the BIB Spreadsheet from Zillaspeak and it gave me some bizarre results (not sure to use this tool correctly) : Suggested Dimensions : Depth=12.51, Width=8.84 and Height=75.42Thank you very much and sorry for my awful English. It would much better in French...
You'll need some series resistance, but you could use a ported box.
Throw the parameters at WinISD.
You can use 20-40L, tuned between 60 and 40Hz respectively, with 5-8ohm series resistance (the option to add resistance is in the "signal" tab).
You'll lose some power in the resistor, but given the high sensitivity of the driver, I don't expect that to be a big problem.
Chris
Throw the parameters at WinISD.
You can use 20-40L, tuned between 60 and 40Hz respectively, with 5-8ohm series resistance (the option to add resistance is in the "signal" tab).
You'll lose some power in the resistor, but given the high sensitivity of the driver, I don't expect that to be a big problem.
Chris
Ok, I think I'll try the BIB. The timing is good, I don't have a regular GF for the moment, so the look and the dimension are not an issue... (I mean the look and the dimension of the enclosure, not the girl friend... )
When I use the BIB calculator from Zillaspeak, I just entered 3 variables : Fs, Vas and Qts and it gave me some results that seem smaller than I thought (for ex. the internal width 8,84 and the nominal height 75,42). Did I do something wrong?
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Measuring them yourself will likely yield different specs, but not because the 1st ones are necessarily wrong. More likely because you are measuring at a different place on the curve/ T/S are not scalars. I have found that factory specs, invariably measured with LEAP or LMS produce an encloure closer to target.
dave
well my only input i can give you to help is the t/s specs for the guide sound units i recently acquired, who's quoted T/S specs were pretty much exactly as listed on the audio nirvana website for the AN8 neo's.
guide-sound being the people who manufacture the audio nirvana units.
Product Show
when i finally measured the T/S specs myself i got
FS - 57.84
Re - 7.6
Le - 51.985
Qt - 0.235
Qe - 0.25
Qm - 2.97
Mms - 13.555
Rms - 1.66
Cms - 0.0005585
Vas - 36.755
Sd - 216
Bl - 12.23
its a huge way off the quoted specs. the units sound very good but it changed any attempts at making an enclosure for them.
i think i remember you mentioning this about some Mark Audio drivers somewhere?
from memory your measurements weren't (in terms of %) that far off the factory measures T/S specs. Certainly not to the extent i've seen from my own measurements of a guidesound unit, and a few other threads dotted around this forum and a few others.
All that does is indicate that the MArk Audio drivers have T/S curves that are closer to horizontal. Hae a look at these measurements of the same pair of FE127eN drivers by Mark & myself (and the factory's for reference (of stock drivers))
dave
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