dasdoing
Major Contributor
on a sidenote, and this is not for audio only: when you want to show off, rehearse
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Blew out the woofers on my brand new speakers, need help to find the cause
- Thread starter NoJo2211
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But this was a one time only demonstration, so if he had rehearsed he wouldn't have been able to do the actual demonstration.
No.
Setting the A/V Receiver Impedance Selector Switch
This article explores the purpose and function of the impedance switch found on some A/V receivers. Tradeoffs of following manufacturers recommended settings are also discussed. YouTube video inside.
dasdoing
Major Contributor
But this was a one time only demonstration, so if he had rehearsed he wouldn't have been able to do the actual demonstration.
hehehhehe
I know it's a joke, but without the show-off pressure he would have started this test at low volume and would have percieved he is at limit before destroying the speakers
Vladimir Filevski
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Ditton 66 impedance is specified as 4 ohm minimum, so do connect them to the 4-ohm amp output.
dasdoing
Major Contributor
Aren't ported speakers suppoused to be high-passed below the port frequency to avoid exactly this?
he said it wasn't extremly loud. also beeing a Youtube video there weren't any signals close to 0dBFS.
I am just wondering it could possibly a design failure, not user error?
he said it wasn't extremly loud. also beeing a Youtube video there weren't any signals close to 0dBFS.
I am just wondering it could possibly a design failure, not user error?
dasdoing
Major Contributor
there is music out there with high energy around that region. So even music could have caused this in normal usage
DVDdoug
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Test tones can be dangerous! A 100W speaker isn't designed for 100W continuously. It's designed to handle 100W on the program peaks with maybe 10-20W average. (It's the short-term average that burns-out speakers.) If you push the amplifier into clipping/distortion the peaks are clipped but the average power keeps going-up.
Also, the tweeter can't handle nearly as much power as the woofer. And you can fry a tweeter with frequencies higher than you can hear and/or higher than the tweeter can reproduce.
If bi-amping bypasses the internal crossover (I would guess that's not possible with the Warefdale) you can fry the tweeter if you foul-up and send bass to the tweeter.
You are most likely to fry a speaker if alcohol is involved, especially if guests have access to the volume control, or "kids", or when you are "testing" to see how loud you can go, or when showing-off.
With the "large" setting the subwoofer is ONLY used for the "point one" LFE channel with movies. All of the "regular bass" goes to the other speakers and with regular stereo music the sub isn't used at all.
Also, the tweeter can't handle nearly as much power as the woofer. And you can fry a tweeter with frequencies higher than you can hear and/or higher than the tweeter can reproduce.
If bi-amping bypasses the internal crossover (I would guess that's not possible with the Warefdale) you can fry the tweeter if you foul-up and send bass to the tweeter.
You are most likely to fry a speaker if alcohol is involved, especially if guests have access to the volume control, or "kids", or when you are "testing" to see how loud you can go, or when showing-off.
Right. When set to "small" the bass is re-directed to the subwoofer.
With the "large" setting the subwoofer is ONLY used for the "point one" LFE channel with movies. All of the "regular bass" goes to the other speakers and with regular stereo music the sub isn't used at all.
That's reasonable. It's hard to get any kind of service these days. And it's important to use the right woofer because the cabinet and woofer are optimized to work together. This is especially true for a ported speaker. And the output is matched to the midrange & tweeter and the crossover may have some tweaks/tuning to optimize that particular woofer.
The output options of the MC500 selects a transformer to adapt the voltage/current output of the amp to the speaker impdedance.
Higher impedance speakers need a higher voltage but lower current to deliver full power compared to a lower impedance speaker, which needs a lower voltage, but higher current. The selection of the correct output allows the amp to deliver full power regardless of the speaker impdance.
Selecting the wrong one won't have any detrimental effect, other than preventing the amp from delivering full power (If you use the 4 ohm output on an 8 ohm speaker, the amp will run out of voltage earlier. Conversely if you use the 8 ohm output with a 4 ohm speaker, it will run out of current earlier)
So you should simply match the output to the impedance rating of your speaker. But take into account the dip as pointed out by @Vladimir Filevski, since that dip is likely to be at the low end where more power is needed.
Having sai that - your amp is not exactly lacking power in the first place, and your speakers are high sensitivity - as you say, plenty of headroom: it is unlikely to be a big issue for you.
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dasdoing
Major Contributor
not everyone uses bookshelf speakers with an AVR, right?
from what I get, this could happen in a loud music scenario, too if there is no protection. how does a loudspeaker manufactor expect that their speaker never recieve a loud 20Hz tone?
If a passive loudspeaker is not designed for low frequencies, why don't manufacturers implement a high pass filter for the woofers in the crossover, like the Arendal 1961?
Why should I be obligated into using Bass Management, if I prefer to send only the LFE channel to a subwoofer?
I believe that if manufacturers don't implement a high pass filter, then I'm not responsible if the woofer smokes with 20 Hz signal, because not all audio devices have one.
Why should I be obligated into using Bass Management, if I prefer to send only the LFE channel to a subwoofer?
I believe that if manufacturers don't implement a high pass filter, then I'm not responsible if the woofer smokes with 20 Hz signal, because not all audio devices have one.
D
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Ahh, really? Are you serious? Are you one of those that would dry your wet dog in the microwave oven if it wasn't warned against in the manual?
- Thread Starter
- #35
Original poster here: Thank you everyone for the discussion. I have learned a lot. Definitely no interest in watching test tone videos in the future. As I mentioned, one of my guests said to try it and 10 seconds later I have smoke. I have already adjusted the speakers to Small and set the crossover to 80Hz for after I complete the repair.
One follow up question, is there any concerns about the Bi-Amping? Is that a potential cause as well or am I fine with this AVR and speaker, assuming of course I wired it correctly. Should I just Bi-Wire instead, or not bother at all?
One follow up question, is there any concerns about the Bi-Amping? Is that a potential cause as well or am I fine with this AVR and speaker, assuming of course I wired it correctly. Should I just Bi-Wire instead, or not bother at all?
Ported (and active) subwoofers normally have this feature. Active speakers will also typically have that and/or active limiters to prevent you from frying the drivers unless you REALLY try.
Passive speakers typically do not have high pass filters. A 10 second continuous sine wave below the port tuning is a very different scenario than normal music, and is what I would consider an active attempt to ruin the drivers. The driver will flap around uncontrollably, bottoming out, possibly tearing the suspension. To even be able to hear a 30hz (not to mention 20hz) sine wave from a speaker like that is a pretty safe sign you're playing way too loud.
One would think the speaker would physically bottom out, resulting in a very loud mechanical rattle, before the voice-coil wiring burned up.
Of course, the rattle may have been there and gone unheeded. But any mechanical rattle from speakers requires immediate action to reduce the volume.
I have run test tones into speakers, both ported and acoustic suspension, sometimes at fairly high power, meaning that I can see the excursion noticeably. No issues. But I was really paying attention for any mechanical noises or overtones. Overtones are easy to hear with 20Hz test tones--If you can hear the tone at all above a muted felt vibration, it's probably an overtone you are hearing.
The worst is with careless handling of input cables when the amp is on, particularly to the unattenuated inputs of a power amp. That will relocate the pictures on the walls and gets the dogs barking throughout the neighborhood. I have not ruined a speaker yet with such occasional mishaps. But their duration was measured in small fractions of a second--sort of a burned hand reaction.
Rick "turn the amp off first, Rick" Denney
Of course, the rattle may have been there and gone unheeded. But any mechanical rattle from speakers requires immediate action to reduce the volume.
I have run test tones into speakers, both ported and acoustic suspension, sometimes at fairly high power, meaning that I can see the excursion noticeably. No issues. But I was really paying attention for any mechanical noises or overtones. Overtones are easy to hear with 20Hz test tones--If you can hear the tone at all above a muted felt vibration, it's probably an overtone you are hearing.
The worst is with careless handling of input cables when the amp is on, particularly to the unattenuated inputs of a power amp. That will relocate the pictures on the walls and gets the dogs barking throughout the neighborhood. I have not ruined a speaker yet with such occasional mishaps. But their duration was measured in small fractions of a second--sort of a burned hand reaction.
Rick "turn the amp off first, Rick" Denney
dasdoing
Major Contributor
would this be a safe method to find out the limits of a subwoofer....provided a slow increase of volume?
Bi-wiring and passive avr bi-amping are more a waste of wire. It shouldn't hurt, it just has no particular benefit. More about marketing. Setting to small and using a crossover is something you should have done from the start, tho....live and learn!
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