Hi,
I hope "crackling" is the right word, I just got a new subwoofer:
SB Acoustics SB20PFC30-4
Which has RMS 50W and Max 100W at 4ohms
SB Acoustics SB20PFC30 - 8" Woofer
I connected it to my amplifier, the Arylic Up2stream 2.1 amp:
2.1 Amplifier with 100W+50W *2 for DIY Audio-Arylic.com
– arylic
Which has power output of:
2x50W@4Ω + 100W@2Ω BTL load at 24V
2x30W@8Ω + 75W@4Ω BTL load at 24V
2x22W@8Ω + 48W@4Ω BTL load at 19V
2x15W@8Ω + 30W@4Ω m BLT load at 15V
The amplifier is powered by a battery board which outputs 21V:
Dayton Audio - LBB-5S 18650 5-24V Input 21V Lithium Battery Board with Balance/Charge Protection
I've read that having a speaker which has more wattage than the amplifier can output, can cause clipping at higher volumes.
I thought that I was safe with this combination but when I have the amplifier at a higher volume (around 70%) I hear a crackling noise coming from the subwoofer.
What could this be? Is my combination of all these parts not right (after I've researched for months trying to find the good combination 🙁 )
There is a bass-gain knob on the amplifier but I've reset it to 0, and checked the negative/positive wires on both the subwoofer and amplifier.
PS. Currently breaking in the subwoofer (not at a high volume), don't know if that should fix the issue.
Also maybe important to say, I only have the subwoofer connected right now, the 2 channels are not connected.
Thanks in advance.
I hope "crackling" is the right word, I just got a new subwoofer:
SB Acoustics SB20PFC30-4
Which has RMS 50W and Max 100W at 4ohms
SB Acoustics SB20PFC30 - 8" Woofer
I connected it to my amplifier, the Arylic Up2stream 2.1 amp:
2.1 Amplifier with 100W+50W *2 for DIY Audio-Arylic.com
– arylic
Which has power output of:
2x50W@4Ω + 100W@2Ω BTL load at 24V
2x30W@8Ω + 75W@4Ω BTL load at 24V
2x22W@8Ω + 48W@4Ω BTL load at 19V
2x15W@8Ω + 30W@4Ω m BLT load at 15V
The amplifier is powered by a battery board which outputs 21V:
Dayton Audio - LBB-5S 18650 5-24V Input 21V Lithium Battery Board with Balance/Charge Protection
I've read that having a speaker which has more wattage than the amplifier can output, can cause clipping at higher volumes.
I thought that I was safe with this combination but when I have the amplifier at a higher volume (around 70%) I hear a crackling noise coming from the subwoofer.
What could this be? Is my combination of all these parts not right (after I've researched for months trying to find the good combination 🙁 )
There is a bass-gain knob on the amplifier but I've reset it to 0, and checked the negative/positive wires on both the subwoofer and amplifier.
PS. Currently breaking in the subwoofer (not at a high volume), don't know if that should fix the issue.
Also maybe important to say, I only have the subwoofer connected right now, the 2 channels are not connected.
Thanks in advance.
If the box is vented, then it could be port chuffing noises. Plug the port with socks or similar and see if it disappears. If it does, then your port velocity is too high so you need to increase the port diameter.
I would guess that you could be clipping the bass amplifier or bottoming the sub woofer voice coil. (You do not want to bottom the VC)
You may find that the lithium ion battery pack sags significantly under load as well. (You can check with a DMM)
Most of these noises are probably masked in normal operation by the 2 main speakers.
I assume you do not have a scope.
You may find that the lithium ion battery pack sags significantly under load as well. (You can check with a DMM)
Most of these noises are probably masked in normal operation by the 2 main speakers.
I assume you do not have a scope.
Cracking noise can mean a bottoming voice coil. Not a good idea to continue playing at that level as the end result would be damage to the driver.
Subwoofer power handling is usually displacement-limited, which means that even though it may be rated to handle a certain power before the voice coil burns up, it might take less power (and sometimes a lot less power) to drive it to Xmech, its maximum excursion before damage. How much power it can take before that happens depends on its t/s parameters and the box size and tuning that you're using it in.
Subwoofer power handling is usually displacement-limited, which means that even though it may be rated to handle a certain power before the voice coil burns up, it might take less power (and sometimes a lot less power) to drive it to Xmech, its maximum excursion before damage. How much power it can take before that happens depends on its t/s parameters and the box size and tuning that you're using it in.
your voice-coil can move around 6-7mm in one direction before hitting the pole-plate.
Without enclosure or with a vented cab only 4-5W are needed to bottom out at low frequencies < 35Hz..
So you have to engage a subsonic filter a second order high-pass of around 30Hz to limit the excursion.
Without enclosure or with a vented cab only 4-5W are needed to bottom out at low frequencies < 35Hz..
So you have to engage a subsonic filter a second order high-pass of around 30Hz to limit the excursion.
Is it not in a box? I think I missed that - if that is a case you will bottom out the VC at quite low levels at low frequencies as pointed out.
FYI/FWIW: An amplifier gain control (input sensitivity) is simply a level-matching device allowing you to match an amplifier's input circuit to a source unit's (or signal processor) output. Ideally gains are set so an amplifier's output "clips" at the same time the source unit "clips".
IME, too often this is the culprit when given the option.
xmax will be reached at different powers depending on enclosure.
No enclosure, very little power to get to xmax.
Ported enclosure little power at low frequencies.
Sealed enclosure, can take higher powers because of pneumatic suspension.
No enclosure, very little power to get to xmax.
Ported enclosure little power at low frequencies.
Sealed enclosure, can take higher powers because of pneumatic suspension.
Thanks for all the replies!
I had indeed not put it in any enclosure, so that's probably the problem.
Will put it in a passive radiator enclosure and let's see what the result is.
And I'll need to read into the "bass gain" comment above, not really sure what it means but nice to know.
I had indeed not put it in any enclosure, so that's probably the problem.
Will put it in a passive radiator enclosure and let's see what the result is.
And I'll need to read into the "bass gain" comment above, not really sure what it means but nice to know.
you're welcome!
That was way too obvious for me to even consider........ 🙁
Among many? others across the net, but one known to be accurate: Gain Structure for Home Theater: Getting the Most from Pro Audio Equipment in Your System | Home Theater Forum and Systems
That was way too obvious for me to even consider........ 🙁
Among many? others across the net, but one known to be accurate: Gain Structure for Home Theater: Getting the Most from Pro Audio Equipment in Your System | Home Theater Forum and Systems