hey guys looking for help. ill be using a mb quart dsc-480 to power one 10" cvr.
ive got the box designed and in winISD....looks good but unfortunately to avoid exceeding the excursion limit of the woofer and maintain high power levels and good spl...the high pass (subsonic) need to be at 30 hz...2nd order (5 hz too low and the sub will probably get out of hand). the amp itself has a dial that goes from 10hz-1.2khz meaning every slight bit the dial is turned will have a huge effect. how can i make sure its at exactly 30 or within at least 2-3 hz???
1 option is to use the hu...as it has a digital readout...problem there is i have to wire the sub up on the rear preout...not sub preout...and i lose the low pass it could have (which i could then use the amp for the low pass filter). i would also lose the ability to adjust the subwoofer phase....this could very well be a good way to do it...most likely simply adjusting the "distance from center" for the sub can be used to compensate...
(by the way if you have winISD i can send you the file to take a look at it...i would post the picks of spl, cone excursion, and what not but that would be a pain....easy to email though)
with the tone generator, you know exactly what frequency you're sending to the amp. with the scope, you can look for where the drop-off starts @ that frequency, and you know you've hit it on the head. Watch your 30Hz waveform, and start turning the ISF down until you see the amplitude start to reduce. Then you know it's begun filtering that frequency.
The right tools for the job always make the work easier.
well talking to my dad the other day...turns out he doesn't have an o-scope anymore...it was used for his old job and i guess his newer job doesn't involve one.
is there any other way to set this exact??
I know in glasswolf's article it says that at 30 hz or so a subsonic isn't needed....he's had a box tuned to 32 hz with no subsonic and no issues...will mine at 31 hz be okay with out one??
It should be, yes. However, if you really want the ISF in place, another option is to build your own passive filter, 2nd order HP with caps and chokes. Use 1% tolerance components and you will be spot on for the accuracy of it.