Hi guys. I am going to "test" my new PA speakers I bought by providing the sound for our neighborhood new-year party. it will be at a small open manual car-wash and the street infront, so my 2x 120dB(z) peak (line source) mains should easily take care. problem is they are made to be crossed at 100Hz or above, so I need a sub. my sub is not a PA sub though. it is prety strong though, in my room at least (using it in 3 o'clock position). I don't expect it to make a full PA subwoofer cause it is obviously not made for this (Kef Kube 12b). since it is rated 114dB max it should at least give me some bass though, so I hope. I also pretend to use the frontwall to add some gain. Now I see some problems beforehand and kindly ask here because I know that a lot of users here have advanced tecnical knowledge:
1) Is this a bad idea? can I damage my sub by playing it at it's limit? (I obviously will be very carefully increasing the volume)
2) the sub plays very deep (rated 22Hz and goes much deeper with room gain) and is sealed. should I use a highpass? at 30Hz-ish or higher?
3) does the low-pass point make any diference?
4) another option would be using my 2 old KRK Rokit 8's to provide the/some bass (would be lowpassing them at 100Hz)
1) Is this a bad idea? can I damage my sub by playing it at it's limit? (I obviously will be very carefully increasing the volume)
2) the sub plays very deep (rated 22Hz and goes much deeper with room gain) and is sealed. should I use a highpass? at 30Hz-ish or higher?
3) does the low-pass point make any diference?
4) another option would be using my 2 old KRK Rokit 8's to provide the/some bass (would be lowpassing them at 100Hz)
Might survive, won't be very loud outdoors and will be probobly be clipping a lot. High Pass recomended (35Hz).
it must lol. I don't have to do this. And I wont do it if it is too risky
expected
it's AMP? how will that sound? distorsion?
seams to be a good idea, yea
A 12" home HiFi driver in a sealed box will do more than nothing, but it's not going to compare to even a fairly cheap 12" PA subwoofer. Can you rent something in?
Chris
Chris
that was my intention. having at least some bass. but some guy on the other forum told me that subwoofers come into dangerous ranges before you can hear it?! I was hoping I could identify it's limit and operate it in it save range.
I tryed, but here you can only rent a full system plus the operator.
I might just use the mains without a sub. it's just an event for neighbours and friends and the music wont be bass heavy anyways
Your subwoofer is reasonably high-quality, and has built-in limiters etc. Check in on it occasionally to make sure it's not solidly into the limiting (I'm assuming there'd be a flashing red light or something) and you'll be fine.
How many places did you call about renting a subwoofer? Most places will do a dry hire (ie, without an engineer).
Chris
How many places did you call about renting a subwoofer? Most places will do a dry hire (ie, without an engineer).
Chris
Short answer: no.
Home use subwoofers "defy Physics Laws" which is impossible, period, by cheating, big time.
A 12" woofer inside a 1 cu ft box drops a lot below 100 Hz or so (just your crossover frequency, go figure) and they "compensate" for that by HEAVILY boosting Bass, say 10dB to 14dB .
Which of course requires exact same amount of extra power ... 10dB is 10X extra power, and so on.
IF well done, they will avoid heavy clipping (farting) and woofer destruction (by over excursion) by heavily processing and limiting signal, calculating real time voice coil excursion, etc.
Does it work?
Within a very limited space (a closed home room) ... yes.
Beware it will be a lot of the time very near absolute maximum output capabilities but that will be "transparent" to you .... at home.
Put that same woofer in an open street, and to boot demand Party levels .... forget it.
Being a well made Kef product, a serious experienced Company, it will not fart, explode or smash voice coils against back plate, it will simply self pad down until safe ... producing very low acoustic output.
I am quite certain you won´t even need to add a 35Hz highpass, it must already be part of its software, it´s not a home made/DIY system coupling an amp and speaker and making you take all decisions; I tust KEF for that, they will NOT allow speaker to self damage.
They say so very clearly in their brochure
Maybe some friend can loan you a Bass Guitar amplifier, those are loud by definition, because they are meant to be used besides a drummer (hint: very loud noisy people 😉 )
You can feed lowpassed signal straight into Power amp IN or Loop Return or even a "CD/Tape IN" which some have to allow home practice with a backing track.
Home use subwoofers "defy Physics Laws" which is impossible, period, by cheating, big time.
A 12" woofer inside a 1 cu ft box drops a lot below 100 Hz or so (just your crossover frequency, go figure) and they "compensate" for that by HEAVILY boosting Bass, say 10dB to 14dB .
Which of course requires exact same amount of extra power ... 10dB is 10X extra power, and so on.
IF well done, they will avoid heavy clipping (farting) and woofer destruction (by over excursion) by heavily processing and limiting signal, calculating real time voice coil excursion, etc.
Does it work?
Within a very limited space (a closed home room) ... yes.
Beware it will be a lot of the time very near absolute maximum output capabilities but that will be "transparent" to you .... at home.
Put that same woofer in an open street, and to boot demand Party levels .... forget it.
Being a well made Kef product, a serious experienced Company, it will not fart, explode or smash voice coils against back plate, it will simply self pad down until safe ... producing very low acoustic output.
I am quite certain you won´t even need to add a 35Hz highpass, it must already be part of its software, it´s not a home made/DIY system coupling an amp and speaker and making you take all decisions; I tust KEF for that, they will NOT allow speaker to self damage.
They say so very clearly in their brochure
(that screams home use)
Maybe some friend can loan you a Bass Guitar amplifier, those are loud by definition, because they are meant to be used besides a drummer (hint: very loud noisy people 😉 )
You can feed lowpassed signal straight into Power amp IN or Loop Return or even a "CD/Tape IN" which some have to allow home practice with a backing track.