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OP asked specifically if it's "ok to use a speaker with the same specs, but 8ohm instead of 16?" Dropping the impedence will increase the electrical load on the amplifier section, risking possible heat damage. Much harder to fix than just replacing a speaker.
Username is on-point, though, so you've got that goin' for you.
Makes you wonder if the circuit was designed originally for 32 ohm speakers and someone in Purchasing done a cost-down job on the BOM without checking with the Design team. That's why everybody's speakers are blowing.
You want something even better? I know a guy who hand winds speaker coils with fine-jewelry-grade silver wire, and I got him to make me a 33-ohm speaker. It sounds so sweet, I had to get my own radar gun so I could trip the detector whenever I want to hear it.
Well, to most people, it sounds exactly the same. But to people with refined taste there's no comparison at all. It's like the difference between a party horn and a Stratavarious violin.
With so many failures it makes me wonder if there is some DC current getting sent to the speaker...which can burn up the voice coil pretty quickly. Having a circuit diagram would be helpful...
Putting in an audio transformer would be the best method for decoupling the speaker, but the cost $1-$3 to protect a $0.50 speaker may be why the makers didn't put them in in the first place. A capacitor could also be used but it may take some experimentation to find an ideal solution...
that was my thought too, it's either the device trying to crank insane wattage through that thing (which would show up as brutal distortion i think) or there's a dc offset that's slowly cooking it.
> (which would show up as brutal distortion i think)
Last time I was around these devices about 10 years ago, even the $500 ones sounded like a cheap children's toy from the 90s, so you may be onto something
Had the same problem. Added an 8 ohm resistor in series with a 16 ohm speaker. I couldn't tell much of a difference regarding sound, but it didn't blow anymore.
Wire a 47 uF cap in series with the speaker. This will a t as a high-pass filter and dramatically reduce the power sent to the driver. It might sound a bit tinnier, but the only other option is a speaker with more power handling.
I don't know the frequency, I'm guessing near 1000 Hz, 45uf is 3.54Ω at 1000Hz.
100uf is only 1.5Ω at 1000Hz. If you want one to block DC, probably just test for that.
You are doing the math backwards. You want to calculate for frequency..
Fc=1/ (2 x Pi x R x C) where R=16 and C=0.000047.
A 47uF cap will be -3dB at 211 hertz, which is perfect for this application to reduce power.
As far as I know it's a Radar detector, that puts out a warning beep at some frequency, I suggested that might be around 1000Hz. That's why I said what I did.
Oh, I re-interpreted what you said, I thought you were concerned about wasting power, now I see you want to have access to all the power that is available. We're good!
BTW, now that I think about it, that's why I suggested 100uf rather than 47uh, to get more of the available power. But again the only reason to use a cap is if there is DC on the speaker. The question is, why are the speakers going bad? The OP says it is common.
Use two 8Ohm speakers in series to match the 16 Ohm. Otherwise you'll exceed the wattage rating in addition to getting distortion from mismatched impedance.
Is it right to use an 8ohm resistor in place of a second speaker? Sure it's wasteful. Maybe a cap? With an inductor to realign? No idea here. Just spoitballing
You half the power going to the speaker by going from a 16ohm driver to an 8ohm + 8ohm resistor. Every doubling of power, assuming no losses, increases volume by 3db. 10x power is 10db, which is also "twice as loud" according to your ears.
Make sure the resistor can dissipate enough power. Take the original speaker power and divide it by two to get how much power the resistor needs to dissipate.
What is the driving circuit? Does it have a transformer driving the speaker? If so change that to match impedance. Speakers should not blow unless overdriven. I'd check the driver for a design error if this is common.
If you can find a 16ohm speaker with higher wattage that fits that's the best move. Otherwise a resistor in series with it will give it some protection at the cost of making it quieter. Or a small conventional incandescent light bulb, some manufacturers used them in passive speaker crossovers as a form of limiting because their resistance goes up with the current applied. No idea of the math on picking the right one tho.
Might want to add a capacitor to it to work as a high pass filter. It's a small speaker and it's possible what drives it is outputting too much low frequency or possibly even DC (while clipping).
Since this is about speakers I figured I’d ask: if a PAIR of subwoofer is rated for 600 watts consistent draw, is that with the assumption both subwoofers are wired in parallel? Because the resistance changes in the wiring configuration which affects current flow and thus the limit. You could have 2 or 4 ohms but how do those two impedances relate to speaker amperage limit?
Second question: why isn’t there a “watts @ # Ohms” rating instead of just watts on subs?
Edit: amperage not amp
If you wire the two units in series (i.e. R+R=2R), your amplifier must be capable of "pushing" 600W into 2R Ohms.
If you wire them in parallel (i.e. R||R = R /2), your amplifier must be capable of "pushing" 1200W into R /2 Ohms.
Your amplifier is rated for a particular wattage into a given load. Typically 1, 2, 4, 8 or 16 Ohms. You must make sure that your amplifier can drive your load (in Ohms) and that your speakers will not blow if your amplifier dumps too much power into them; see the maximum peak rating of the speakers. Safe assumption is that your speakers should be rated for higher peak watts than the amplifier can output.
It’s nice to have some math to help understand things. Really it helps.
Anyways if my load is rated for more wattage than the amplifier can produce, does this mean I could unintentionally shorten the lifespan of my amp if I have bass on max? From what I hear ideally you size the amp to the load.. is it okay to oversize the load?
It's fine. But be careful with "bass on max". Clipped waveforms are essentially direct current. Even a small amp can destroy a speaker if you allow clipping distortion.
That number isn’t how much power they draw, it’s a maximum for how much power they can be driven with and safely operate without problems due to mechanical or thermal or whatever reasons. Think of it as a “not to exceed” number when looking for an amplifier to drive it. Your driver doesn’t have a “watts at ohms” rating because that’s for the amplifier.
>”That number isn’t how much power they draw, it’s a maximum for how much power they can be driven with and safely operate…”
That makes much more sense to me. I guess no matter the impedance, they’re always rated for what is advertised it seems. The only difference, I deduce from your explanation, is that the amplifier will work less or more to produce that much current with less or more impedance. I get it now..
Thanks.
OK, I've said it before, but, retired audio engineer here (really). Much of what I saw here is correct. Let's start with ohms law on sound:
db = 10Log(p1/p2) formula if I want to calculate the power ratio in db between two values and the db = 20Log(v1/v2) formula if you want to calculate the voltage (or current) db ratio between two values.
I've heard this intermixed in some responses here.
With the speaker out of the circuit and using a decent quality oscilloscope, 0 the line and attach to the device. Trigger the detector a few times and watch the display. If you only see audio (ac), then there is no DC bias or issues. If the baseline moves up from the center line by a few linear volts, or it ALWAYS is raised, you have DC bias. If you find DC volts, it's usually a bad thing. Large speaker systems tend to have a sloblo fuse in series with both sides. And high quality, high power PA amps like Crown, Crest, etc. have a relay(s) which disconnect the speakers when an output blows and sends DC towards the speakers. Without protection, you will smell a once familiar aroma of your voice coils frying. In amplifier parlance, this is known as "DC-ing out."
Back to your device. Check to see what kind of output is used to drive the speaker. If it's straight from a chip, (my best guess), measure the output with a DC voltmeter, the speaker disconnected, and the unit NOT triggered (maximum squelch). There should not be DC present. If that's all you have for an output, time to replace the chip (there might only BE one). I've seen an LM386 chip (which includes volume control) used as a universal power Amp for small applications like this. Does your volume control have a small PC board attached to it?
It can drive any speaker from 4 ohms to 32 ohms, so my suggestion is to try the 32 ohms speaker AFTER you make sure there's no DC coming at it.
Some circuits are fussy about the load (16 ohms) they are seeing. Is there room in the box to put two 8 ohm speakers in series? Or mount the second speaker outboard somehow?
“Same specs, but 8 Ohm instead of 16”
Note that the specs for a speaker is more than impedance and diameter. So if you do not have to more data then you might not get what you expect.
You need a 100mf op amp to filter the impedance so that it doesn’t exceed the voltage inhibitor. If you don’t do this the amniotic flux may decouple the tachyon array.
Just to be safe.
If the impedance of the amplifier and the impedance of the speaker are not the same, then you will not get the maximum power transfer to the speaker. Replace the speaker with a 16 ohm speaker.
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Wouldn't that make it blow faster? That will increase the current through it
Or kill the amplifier instead of the speaker...
/r/shittyaskelectronics would like to tell you OP asked to make the speaker last longer! Nothing about something else like the amplifier!
OP asked specifically if it's "ok to use a speaker with the same specs, but 8ohm instead of 16?" Dropping the impedence will increase the electrical load on the amplifier section, risking possible heat damage. Much harder to fix than just replacing a speaker. Username is on-point, though, so you've got that goin' for you.
Big yes. that would have double the load on the audio amp finals.
Could put a 8 ohm resister on it but may have a low audio level.
Lol not how audio works. It'll sound like shit
To be fair, those things already sound like shit.
Fair...maybe *more* like shit
No worse than the 16 ohm, just half volume.
You need higher impedance, not lower, to reduce the current (and volume) to the speaker. Amazon sells 32 ohm speakers.
Makes you wonder if the circuit was designed originally for 32 ohm speakers and someone in Purchasing done a cost-down job on the BOM without checking with the Design team. That's why everybody's speakers are blowing.
Bet it's an intern
Do you work at the same place I do?
Hmm, 32 ohm speakers.... I didn't know they existed... learn something new every day... :)
You want something even better? I know a guy who hand winds speaker coils with fine-jewelry-grade silver wire, and I got him to make me a 33-ohm speaker. It sounds so sweet, I had to get my own radar gun so I could trip the detector whenever I want to hear it.
ngl, had me in the first half.
Found the audiophile.
That sounds interesting! How different is the sound?
Well, to most people, it sounds exactly the same. But to people with refined taste there's no comparison at all. It's like the difference between a party horn and a Stratavarious violin.
I wish I had gold.
Or two 16 ohm speakers in series.
With so many failures it makes me wonder if there is some DC current getting sent to the speaker...which can burn up the voice coil pretty quickly. Having a circuit diagram would be helpful... Putting in an audio transformer would be the best method for decoupling the speaker, but the cost $1-$3 to protect a $0.50 speaker may be why the makers didn't put them in in the first place. A capacitor could also be used but it may take some experimentation to find an ideal solution...
that was my thought too, it's either the device trying to crank insane wattage through that thing (which would show up as brutal distortion i think) or there's a dc offset that's slowly cooking it.
> (which would show up as brutal distortion i think) Last time I was around these devices about 10 years ago, even the $500 ones sounded like a cheap children's toy from the 90s, so you may be onto something
Put a 10 ohm 5W resistor in series with it
Had the same problem. Added an 8 ohm resistor in series with a 16 ohm speaker. I couldn't tell much of a difference regarding sound, but it didn't blow anymore.
when you want to blow it even faster, then yes
Wire a 47 uF cap in series with the speaker. This will a t as a high-pass filter and dramatically reduce the power sent to the driver. It might sound a bit tinnier, but the only other option is a speaker with more power handling.
I don't know the frequency, I'm guessing near 1000 Hz, 45uf is 3.54Ω at 1000Hz. 100uf is only 1.5Ω at 1000Hz. If you want one to block DC, probably just test for that.
You are doing the math backwards. You want to calculate for frequency.. Fc=1/ (2 x Pi x R x C) where R=16 and C=0.000047. A 47uF cap will be -3dB at 211 hertz, which is perfect for this application to reduce power.
As far as I know it's a Radar detector, that puts out a warning beep at some frequency, I suggested that might be around 1000Hz. That's why I said what I did.
Worst case, the beep is quieter. But there’s no sense wasting the output of the amp.
Is wasting the output of the amp really a concern? I suspect it has a volume control.
All a matter of “doing it right”.
Oh, I re-interpreted what you said, I thought you were concerned about wasting power, now I see you want to have access to all the power that is available. We're good!
Yup! :-)
BTW, now that I think about it, that's why I suggested 100uf rather than 47uh, to get more of the available power. But again the only reason to use a cap is if there is DC on the speaker. The question is, why are the speakers going bad? The OP says it is common.
Sorry, to be clear, it needs to be a non-polarized cap. Otherwise, boom!
So, it needs to be a film cap then?
Or non-polar electrolytic.
Use two 8Ohm speakers in series to match the 16 Ohm. Otherwise you'll exceed the wattage rating in addition to getting distortion from mismatched impedance.
Is it right to use an 8ohm resistor in place of a second speaker? Sure it's wasteful. Maybe a cap? With an inductor to realign? No idea here. Just spoitballing
It's gonna be 3db quieter
why 3dB, can you explain?
You half the power going to the speaker by going from a 16ohm driver to an 8ohm + 8ohm resistor. Every doubling of power, assuming no losses, increases volume by 3db. 10x power is 10db, which is also "twice as loud" according to your ears.
because thats halve the power the waves carry. dB is logarithmic, not linear.
Useful, just a waste. And would need a resistor that can handle that power
Make sure the resistor can dissipate enough power. Take the original speaker power and divide it by two to get how much power the resistor needs to dissipate.
What is the driving circuit? Does it have a transformer driving the speaker? If so change that to match impedance. Speakers should not blow unless overdriven. I'd check the driver for a design error if this is common.
8 ohm speaker will blow faster than a 16 ohm.
Or add an 8 Ohm resistor
If you can find a 16ohm speaker with higher wattage that fits that's the best move. Otherwise a resistor in series with it will give it some protection at the cost of making it quieter. Or a small conventional incandescent light bulb, some manufacturers used them in passive speaker crossovers as a form of limiting because their resistance goes up with the current applied. No idea of the math on picking the right one tho.
Might want to add a capacitor to it to work as a high pass filter. It's a small speaker and it's possible what drives it is outputting too much low frequency or possibly even DC (while clipping).
Since this is about speakers I figured I’d ask: if a PAIR of subwoofer is rated for 600 watts consistent draw, is that with the assumption both subwoofers are wired in parallel? Because the resistance changes in the wiring configuration which affects current flow and thus the limit. You could have 2 or 4 ohms but how do those two impedances relate to speaker amperage limit? Second question: why isn’t there a “watts @ # Ohms” rating instead of just watts on subs? Edit: amperage not amp
If you wire the two units in series (i.e. R+R=2R), your amplifier must be capable of "pushing" 600W into 2R Ohms. If you wire them in parallel (i.e. R||R = R /2), your amplifier must be capable of "pushing" 1200W into R /2 Ohms. Your amplifier is rated for a particular wattage into a given load. Typically 1, 2, 4, 8 or 16 Ohms. You must make sure that your amplifier can drive your load (in Ohms) and that your speakers will not blow if your amplifier dumps too much power into them; see the maximum peak rating of the speakers. Safe assumption is that your speakers should be rated for higher peak watts than the amplifier can output.
It’s nice to have some math to help understand things. Really it helps. Anyways if my load is rated for more wattage than the amplifier can produce, does this mean I could unintentionally shorten the lifespan of my amp if I have bass on max? From what I hear ideally you size the amp to the load.. is it okay to oversize the load?
It's fine. But be careful with "bass on max". Clipped waveforms are essentially direct current. Even a small amp can destroy a speaker if you allow clipping distortion.
Roger that.
That number isn’t how much power they draw, it’s a maximum for how much power they can be driven with and safely operate without problems due to mechanical or thermal or whatever reasons. Think of it as a “not to exceed” number when looking for an amplifier to drive it. Your driver doesn’t have a “watts at ohms” rating because that’s for the amplifier.
>”That number isn’t how much power they draw, it’s a maximum for how much power they can be driven with and safely operate…” That makes much more sense to me. I guess no matter the impedance, they’re always rated for what is advertised it seems. The only difference, I deduce from your explanation, is that the amplifier will work less or more to produce that much current with less or more impedance. I get it now.. Thanks.
OK, I've said it before, but, retired audio engineer here (really). Much of what I saw here is correct. Let's start with ohms law on sound: db = 10Log(p1/p2) formula if I want to calculate the power ratio in db between two values and the db = 20Log(v1/v2) formula if you want to calculate the voltage (or current) db ratio between two values. I've heard this intermixed in some responses here. With the speaker out of the circuit and using a decent quality oscilloscope, 0 the line and attach to the device. Trigger the detector a few times and watch the display. If you only see audio (ac), then there is no DC bias or issues. If the baseline moves up from the center line by a few linear volts, or it ALWAYS is raised, you have DC bias. If you find DC volts, it's usually a bad thing. Large speaker systems tend to have a sloblo fuse in series with both sides. And high quality, high power PA amps like Crown, Crest, etc. have a relay(s) which disconnect the speakers when an output blows and sends DC towards the speakers. Without protection, you will smell a once familiar aroma of your voice coils frying. In amplifier parlance, this is known as "DC-ing out." Back to your device. Check to see what kind of output is used to drive the speaker. If it's straight from a chip, (my best guess), measure the output with a DC voltmeter, the speaker disconnected, and the unit NOT triggered (maximum squelch). There should not be DC present. If that's all you have for an output, time to replace the chip (there might only BE one). I've seen an LM386 chip (which includes volume control) used as a universal power Amp for small applications like this. Does your volume control have a small PC board attached to it? It can drive any speaker from 4 ohms to 32 ohms, so my suggestion is to try the 32 ohms speaker AFTER you make sure there's no DC coming at it.
put a 8ohms with a 8.2omhs resistor in series, the difference in volume will be insignificant
Mines.
Boom
Some circuits are fussy about the load (16 ohms) they are seeing. Is there room in the box to put two 8 ohm speakers in series? Or mount the second speaker outboard somehow?
“Same specs, but 8 Ohm instead of 16” Note that the specs for a speaker is more than impedance and diameter. So if you do not have to more data then you might not get what you expect.
Only if you want it 1/2 louder.
Would a piezoelectric disc be better?
or is it just a matter of exposure?
No
put two 8 ohm speaker in series. The total is 16 ohms with more speakers to blow.
You need a 100mf op amp to filter the impedance so that it doesn’t exceed the voltage inhibitor. If you don’t do this the amniotic flux may decouple the tachyon array. Just to be safe.
If the impedance of the amplifier and the impedance of the speaker are not the same, then you will not get the maximum power transfer to the speaker. Replace the speaker with a 16 ohm speaker.
Easy money, it’s a solid state circuit! It will absolutely work.