hi all
im trying to sim my driver (vifa ne315w-04) and come up with a vented design to mate to a ss 2905-9900 an ss 18w 8531g and am having a little trouble
the top of the design is troels gravesens jensen and uses his passive crossover
for the low end ive substituted the revelater bass driver(to expensive) for the vifa mentioned above and have a mini dsp to cross the bass over to the mid at 200hz as per troels original design and have 80lts max volunme for the bass driver as the cabs are already built ,i can reduce that volume if need be to watever will work the best
now ive been using unibox and 80l gives me fb 33.5hz and f3 30.76hz with a 10.59cm diam port x 16cm long
xmax is reached at 26.8hz for 150w
can someone please look over this for me or offer some advice ,it seems ok to me but im still a noob and dont want to muck it up
also what should i be looking for as far as port speed goes ?
any way thanks in advance for any help any one can offer
cheers sheafer
im trying to sim my driver (vifa ne315w-04) and come up with a vented design to mate to a ss 2905-9900 an ss 18w 8531g and am having a little trouble
the top of the design is troels gravesens jensen and uses his passive crossover
for the low end ive substituted the revelater bass driver(to expensive) for the vifa mentioned above and have a mini dsp to cross the bass over to the mid at 200hz as per troels original design and have 80lts max volunme for the bass driver as the cabs are already built ,i can reduce that volume if need be to watever will work the best
now ive been using unibox and 80l gives me fb 33.5hz and f3 30.76hz with a 10.59cm diam port x 16cm long
xmax is reached at 26.8hz for 150w
can someone please look over this for me or offer some advice ,it seems ok to me but im still a noob and dont want to muck it up
also what should i be looking for as far as port speed goes ?
any way thanks in advance for any help any one can offer
cheers sheafer
it seems to be a balancing act between fb,f3 ,port speed and driver excursion
ive tried to keep the f3 as low as possible whilst keeping the driver away from xmax in the usable range and port speed as low as possible also
i can use the minidsp peq to filter /cut any frequencys i need as well it seems to be very flexable
i hope i,m on the right track
cheers sheafer
ive tried to keep the f3 as low as possible whilst keeping the driver away from xmax in the usable range and port speed as low as possible also
i can use the minidsp peq to filter /cut any frequencys i need as well it seems to be very flexable
i hope i,m on the right track
cheers sheafer
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please help guys
i need to finnish this design
should i pick the lowest tuning i can get or go for say 30hz fb
should i go for a flat tuning or peak and what is a realistic power level to set in unibox to model with ,ive been using 150w but i see others using 50 or so watts
cheers sheafer
i need to finnish this design
should i pick the lowest tuning i can get or go for say 30hz fb
should i go for a flat tuning or peak and what is a realistic power level to set in unibox to model with ,ive been using 150w but i see others using 50 or so watts
cheers sheafer
re:'it seems to be a balancing act ' - yes, and the balance depends on what you're using the speakers for, which you haven't told us. Home theatre - tune low; Music, tune a bit higher; High volume - worry about port size, low volume, port size isn't much of an issue... A link to the specs of your woofer would help too
hi petemck
here is a link to the bass driver
http://www.d-s-t.com.au/data/Vifa/NE315W-04.pdf
the system is used for 2 channel music so i would like nice accurate bass but i also enjoy the kick of ported designs
the system is driven by icepower asx2 modules in btl mode so 500w per bass driver
here is the top cabs which are running off troels passive crossover design and also run from icepower ax2 modules in btl mode so 500w per cab
Jensen-
cheers
ps please forgive my first post it is a little hard to read
here is a link to the bass driver
http://www.d-s-t.com.au/data/Vifa/NE315W-04.pdf
the system is used for 2 channel music so i would like nice accurate bass but i also enjoy the kick of ported designs
the system is driven by icepower asx2 modules in btl mode so 500w per bass driver
here is the top cabs which are running off troels passive crossover design and also run from icepower ax2 modules in btl mode so 500w per cab
Jensen-
cheers
ps please forgive my first post it is a little hard to read
Last edited:
Hi,
Forget about f-3dB, instead optimise for F-6dB and F-10dB, this will compromise
F-3dB but forget that, you will get lower port tunings and better transient
response, and a more room gain friendly roll off than with F-3dB.
Best ported tunings are not flat, they roll-off from quite high slower than sealed.
Simple sims using WinISD indicate 80L sealed, Qbox 0.5 works well, and
the same box tuned to Fvent=18Hz gives IMO the best vented response.
rgds, sreten.
Forget about f-3dB, instead optimise for F-6dB and F-10dB, this will compromise
F-3dB but forget that, you will get lower port tunings and better transient
response, and a more room gain friendly roll off than with F-3dB.
Best ported tunings are not flat, they roll-off from quite high slower than sealed.
Simple sims using WinISD indicate 80L sealed, Qbox 0.5 works well, and
the same box tuned to Fvent=18Hz gives IMO the best vented response.
rgds, sreten.
g,day all
hi sreten and petemck
i will try your suggestions and see how it looks
a few more questions for you all
1/ what power level should i use for the modeling in unibox ,is 50w ok
2/ what should i look for in the step reponse graph for a good result
3/ i have read in the elsinore thread that a good starting point for bass reflex is to aim for fb/f3 = 1.2 to 1.3 , any oppinions?
4/ what box stuffing should i model with ,i can choose between no fill ,minimal fill ,heavy fill and lined walls ?
i think no 3 will achieve what sreten is saying about a more room freindly rolloff
here is an example using joe rasmussens recomendations ,f3/fb =1.27
hi sreten and petemck
i will try your suggestions and see how it looks
a few more questions for you all
1/ what power level should i use for the modeling in unibox ,is 50w ok
2/ what should i look for in the step reponse graph for a good result
3/ i have read in the elsinore thread that a good starting point for bass reflex is to aim for fb/f3 = 1.2 to 1.3 , any oppinions?
4/ what box stuffing should i model with ,i can choose between no fill ,minimal fill ,heavy fill and lined walls ?
i think no 3 will achieve what sreten is saying about a more room freindly rolloff
here is an example using joe rasmussens recomendations ,f3/fb =1.27
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g,day all
here is another box model fb/f3 is 1.33 so bass should be nice and tight
74 l cab fb 23hz f3 31hz response peak is low at .31db
port length and dia is also manageable at 390mm x 90mm
sim is with walls lined no fill
cheers sheafer
here is another box model fb/f3 is 1.33 so bass should be nice and tight
74 l cab fb 23hz f3 31hz response peak is low at .31db
port length and dia is also manageable at 390mm x 90mm
sim is with walls lined no fill
cheers sheafer
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