I tried to look up the symptoms on here and the internet but I'm not sure I got the right answer. Here's the setup & the symptom.
5.1.2 surround speakers on a Marantz SR8012 AV Receiver, stated 140watts per channel at 8ohms.
Polk TSI300 floor standing speakers with 5.25" woofers, rated to 150 watts handling each at 8 ohms. Bi-amped to 2 channels from the Marantz for each speaker, I'm assuming I bi-amped them rather than bi-wiring.
Crossover set at 80hz with subwoofer, not sure at what order (1st, 2nd or 3rd), not much below 80hz should be going to these speakers.
The problem:
The woofers will flap loudly when watching certain movies that have very bassy audio tracks. It's very occasional, so not every movie does this. A movie like Blade Runner 2049 does it alot. It only happens on the floorstanding speakers, which are the only speakers in the setup that are bi-amped.
What I think may be happening:
Since the marantz is putting out 140wpc, and I've bi-amped 2 channels to each floorstanding speaker, I'm assuming that I'm overloading the woofer coils with too much wattage. If the whole speaker (2 woofers, 1 tweeter) can handle 150 watts, then maybe by bi-amping it can only handle some of that when you send 140 watts to the tweeter and 140 watts to the woofers.
What I'd like to know:
It only flaps during extreme bassy moments in some movies, and doesn't make bad sounds otherwise or when playing music so is it possible I'm exceeding tolerance but haven't damaged the speakers yet? What do you think is happening? Is it likely that I've broken them or not? I've read that it's better to have a higher RMS per channel amp with a lower RMS speaker than vice versa because sending low-wattage overdriven amp signals to hi-wattage speakers can damage, isn't that true? Should I be fine if I just don't bi-amp these speakers and rather send one channel to each?
5.1.2 surround speakers on a Marantz SR8012 AV Receiver, stated 140watts per channel at 8ohms.
Polk TSI300 floor standing speakers with 5.25" woofers, rated to 150 watts handling each at 8 ohms. Bi-amped to 2 channels from the Marantz for each speaker, I'm assuming I bi-amped them rather than bi-wiring.
Crossover set at 80hz with subwoofer, not sure at what order (1st, 2nd or 3rd), not much below 80hz should be going to these speakers.
The problem:
The woofers will flap loudly when watching certain movies that have very bassy audio tracks. It's very occasional, so not every movie does this. A movie like Blade Runner 2049 does it alot. It only happens on the floorstanding speakers, which are the only speakers in the setup that are bi-amped.
What I think may be happening:
Since the marantz is putting out 140wpc, and I've bi-amped 2 channels to each floorstanding speaker, I'm assuming that I'm overloading the woofer coils with too much wattage. If the whole speaker (2 woofers, 1 tweeter) can handle 150 watts, then maybe by bi-amping it can only handle some of that when you send 140 watts to the tweeter and 140 watts to the woofers.
What I'd like to know:
It only flaps during extreme bassy moments in some movies, and doesn't make bad sounds otherwise or when playing music so is it possible I'm exceeding tolerance but haven't damaged the speakers yet? What do you think is happening? Is it likely that I've broken them or not? I've read that it's better to have a higher RMS per channel amp with a lower RMS speaker than vice versa because sending low-wattage overdriven amp signals to hi-wattage speakers can damage, isn't that true? Should I be fine if I just don't bi-amp these speakers and rather send one channel to each?
What's happening? Simple. You're hitting the speakers with a lot of low frequency content, below box tuning (Fb). Below Fb a vented box ultimately unloads at 24dB/octave; it no longer provides any loading on the drivers, so excursion increases significantly. The only solution is to either filter off the low frequencies below box tuning so this doesn't happen, or turn the volume down so it isn't as bad.
Passive biamping does not increase the power being delivered to the speakers. It merely changes the bandwidth that each amp delivers. It's a useless gimmick that AVR manufacturers add in to think you are getting value for otherwise unused channels. It's a small software change so it costs them nothing, but may garner a few more sales as it seems to value add to some customers..
Scott has answered most of what I would have on your problem, but I would also ask, are the L/R set to small? If not, try changing that.
If the enclosure was sealed would it not do this? Or with the current ported enclosure if I stuffed roxul insulation into the port would it tame the excursion?
Hi everybody.
Sorry to dig out this old thread. My woofers flap when there is high bass material, but only the top woofer of each channel flap. The top and bottom woofer are wired in series. So to clarify - speaker has 4 woofers, 2 on each side, but only the top woofers of each is flapping. Any ideas ? Thanks!
Sorry to dig out this old thread. My woofers flap when there is high bass material, but only the top woofer of each channel flap. The top and bottom woofer are wired in series. So to clarify - speaker has 4 woofers, 2 on each side, but only the top woofers of each is flapping. Any ideas ? Thanks!
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GoTo Post 2
Other thoughts: Are you sure they are simply wired in series ?, are they in same enclosure or sealed off from each other?
GoTo Post 2
Other thoughts: Are you sure they are simply wired in series ?, are they in same enclosure or sealed off from each other?
The woofers are peerless 835016. Both top woofer's dust cap are cracked, but I have used tape to cover them as soon as the cracks appear.
Woofers are all in a cardioid enclosure. Top and bottom woofer are separated by a divider in the enclosure. Top woofer box liter's are slightly smaller to include 2 speaker connectors.
The fact that both drivers do it really points to the source/amplification and to the design of the speakers themselves.
Although one can't rule out driver old age, check the surrounds
If you really want to, swap just one pair from top to bottom, that will pinpoint or not a problem in a certain area.
Although one can't rule out driver old age, check the surrounds
If you really want to, swap just one pair from top to bottom, that will pinpoint or not a problem in a certain area.