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I can't find an answer on this so wanted to ask here.

 

I got a pair of RP-600ms and they are rated down to 45hz.

 

Since I can not set the crossover on my amp, what happens to all of the frequencies less than 45hz that will be sent to the 600s?

 

Do I have to worry about this at high volumes? Ideally I would the sub handling all of these but my receiver sends full range regardless of if a sub is plugged in.

 

Some had said that distortion and potential damage are reasons to set crossover(if able) to say 80hz. Since I can't do that, do I have anything to worry about?

 

In the future if I get a receiver where I can set crossover, can I theoretically play them at higher volumes without distortion? Thank you.

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9 minutes ago, psykoticboss said:

I can't find an answer on this so wanted to ask here.

 

I got a pair of RP-600ms and they are rated down to 45hz.

 

Since I can not set the crossover on my amp, what happens to all of the frequencies less than 45hz that will be sent to the 600s?

 

Do I have to worry about this at high volumes? Ideally I would the sub handling all of these but my receiver sends full range regardless of if a sub is plugged in.

 

Some had said that distortion and potential damage are reasons to set crossover(if able) to say 80hz. Since I can't do that, do I have anything to worry about?

 

In the future if I get a receiver where I can set crossover, can I theoretically play them at higher volumes without distortion? Thank you.

 

No need to worry about this. Most modern amplifiers have a frequency range between 20Hz and 20kHz (or even higher) and few speakers will pick up the frequencies below 50Hz. I don't know what happens to that 'energy', but I'm sure it is not damaging your RP600Ms. Relax and enjoy the music!

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4 minutes ago, MeloManiac said:

 

No need to worry about this. Most modern amplifiers have a frequency range between 20Hz and 20kHz (or even higher) and few speakers will pick up the frequencies below 50Hz. I don't know what happens to that 'energy', but I'm sure it is not damaging your RP600Ms. Relax and enjoy the music!

Well that doesn't make complete sense right? What if I had tower speakers with big woofers that were able to play say down to 30hz..surely I wouldn't just be losing all that bass potential of the towers if it wasn't sending anything less than 50hz. I think you may be right though that I needn't worry about it. Since they are on warranty for 5 years I am not too worried about damage but moreso is distortion common with lower frequencies. Ill have the sub in a few weeks and will be able to properly test. Hoping the 600s sound clear and nice even at loud volumes sending them full range. 

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1 minute ago, psykoticboss said:

Well that doesn't make complete sense right? What if I had tower speakers with big woofers that were able to play say down to 30hz..surely I wouldn't just be losing all that bass potential of the towers if it wasn't sending anything less than 50hz. I think you may be right though that I needn't worry about it. Since they are on warranty for 5 years I am not too worried about damage but moreso is distortion common with lower frequencies. Ill have the sub in a few weeks and will be able to properly test. Hoping the 600s sound clear and nice even at loud volumes sending them full range. 

Well, your amp is sending out the (amplified) signal to the speakers at this moment, but they don't do anything with the low frequencies. Your sub will be able to turn that signal into soundwaves,.

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Just now, MeloManiac said:

Well, your amp is sending out the (amplified) signal to the speakers at this moment, but they don't do anything with the low frequencies. Your sub will be able to turn that signal into soundwaves,.

Ah gotcha. Yeah I couldn't find any information specifically saying what the 600s do with those frequencies. You would like it would be listed as some type of filter, like under the specs it would say 45hz low pass filter or something. But you are pretty sure it has a filter that ignores anything below what it can produce?

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This thread is interesting:

All speakers can reproduce down to 1Hz. All that will happen is that you won't hear it. You'll literally see the driver moving one time per second and that'll be it. It's not damaging for this to happen.

However, when a speaker tries to reproduce a broader bandwidth than it's ideally suited for you get inaccuracies in that reproduction, known as distortion. The driver either isn't going to be fast enough or it's not going to move enough air for you to hear it. So we filter out what's not necessary for the driver to produce anyway, so what it does produce comes through with less distortion due to the driver not trying to do more than necessary.

Limiting the power to a speaker is another issue altogether and it has to do with how much the speaker can move without damaging itself.

https://gearspace.com/board/so-much-gear-so-little-time/747517-what-happens-when-you-feed-speaker-signal-goes-beyond-its-frequency-range.html

 

So the 'filter' (or crossover) is basically filtering out the frequencies and energy that would otherwise damage the woofer.

This is, I guess, why you have to respect the specs of the capacitors, when you 'recap' old speakers (which I did with my 1972 Heresies).

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4 minutes ago, MeloManiac said:

This thread is interesting:

All speakers can reproduce down to 1Hz. All that will happen is that you won't hear it. You'll literally see the driver moving one time per second and that'll be it. It's not damaging for this to happen.

However, when a speaker tries to reproduce a broader bandwidth than it's ideally suited for you get inaccuracies in that reproduction, known as distortion. The driver either isn't going to be fast enough or it's not going to move enough air for you to hear it. So we filter out what's not necessary for the driver to produce anyway, so what it does produce comes through with less distortion due to the driver not trying to do more than necessary.

Limiting the power to a speaker is another issue altogether and it has to do with how much the speaker can move without damaging itself.

https://gearspace.com/board/so-much-gear-so-little-time/747517-what-happens-when-you-feed-speaker-signal-goes-beyond-its-frequency-range.html

 

So the 'filter' (or crossover) is basically filtering out the frequencies and energy that would otherwise damage the woofer.

This is, I guess, why you have to respect the specs of the capacitors, when you 'recap' old speakers (which I did with my 1972 Heresies).

So if all speakers can reproduce it, does that mean the frequency response is actually where they put the crossover limit at, aka where they guessed that it could handle down to without distortion or damage potential? 

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1 minute ago, psykoticboss said:

So if all speakers can reproduce it, does that mean the frequency response is actually where they put the crossover limit at, aka where they guessed that it could handle down to without distortion or damage potential? 

Yes, when they say the frequency response is e.g. 45Hz, it means the filter will allow the speaker to safely produce soundwaves (and higher).

Actually, I have one or two recordings that come with a warning that it could damage your speakers, eg because they 've used a 16Hz organ pipe. But that is utterly wrong. The crossover/speaker combo will rarely be able to reproduce that 16Hz organ pipe... let alone damage it.

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3 minutes ago, MeloManiac said:

Yes, when they say the frequency response is e.g. 45Hz, it means the filter will allow the speaker to safely produce soundwaves (and higher).

Actually, I have one or two recordings that come with a warning that it could damage your speakers, eg because they 've used a 16Hz organ pipe. But that is utterly wrong. The crossover/speaker combo will rarely be able to reproduce that 16Hz organ pipe... let alone damage it.

Yeah I wish they specified that more but it makes sense if it 'blocks' the speaker from even trying to reproduce 45 and below. I will set my sub crossover starting at 50 and see how it goes. Might adjust from there. Thanks for your input man.

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Man that link left me more confused that I already was haha. It seems nobody has a clear answer on if there is a low pass filter or not. So I am still up in the air over if <45 can potentially damage them. Hopefully there is a low pass filter. I am waiting to hear back from Klipsch support I will let you know what they say. 

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2 hours ago, psykoticboss said:

It seems nobody has a clear answer on if there is a low pass filter or not.

 

Somebody just woke me up with her snoring, so I'm going to tinker with this. I'm worse, but it doesn't wake me or her for some reason. : )

 

A low pass filter allows lower frequencies, a low cut filter (also called a high pass filter) blocks low frequencies. I assume the latter is what you are referring to when you're hoping that something in your system is disallowing music with frequency content less than your loudspeaker can properly reproduce.

 

Low cut filters are used on each passband (woofer, midrange, tweeter, etc.) of loudspeakers intended for concert production because those systems are driven near their physical limits (heat and excursion, or how far the driver is allowed to move). Low cut filters are also seen in home audio systems, but rarely for woofers because their physical limits are rarely approached, cost is much more of a factor and because these filters introduce phase errors that compromise the quality of low frequency sound if not done carefully. Low cut filters are used in home audio subwoofer systems that are expected to be driven to their limits.

 

The answer to your not-so-simple question, Part 1

It's physics, but it's not hard and wildly entertaining to nut cases like us, so hang in there. Of the two loudspeaker failure modes; over-heating and over-excursion, over-heating is by far the more frequent loudspeaker killer. In home audio this kind of heat build up during long-term, very loud music playback isn't likely as it would cause permanent damage with your neighbors quicker than your loudspeakers. BUT if your amplifier is large enough and you drop a needle on a record or crank the volume to 11 during movie explosions, you may cause permanent damage to the woofer due to over-excursion. This damage is extremely rare even after doing something dumb (personal knowledge borne of much experience). Why is damaging over-excursion so rare? Because the physics of moving coil loudspeaker systems limits excursion below the region where the loudspeaker can reproduce sound.

 

The answer to your not-so-simple question, Part 2

Your woofer can move only so far outward from rest, or inward from rest, before it is damaged. Your woofer also produces a range of frequencies, and as you go lower in frequency, it has to move further in and out to produce a constant sound pressure level (flat frequency response). It just so happens that a loudspeaker driver has to move four times further in and out as frequency reduces by half. This quadrupling of excursion to maintain flat sound pressure level or frequency response is a 12dB per octave increase in excursion. Say your loudspeaker is flat down to 45Hz, then rolls off at 12dB per octave under 45Hz. THAT MEANS THE WOOFER STOPS INCREASING EXCURSION UNDER 45Hz. Yea! Thus if your loudspeakers sound good at the volume you are playing, there's nothing bad being done to the woofer at frequencies less that what you are hearing. BTW, it's most likely that your loudspeaker system rolls off by at least 24dB per octave, thus excursion is actually reducing as frequency decreases under 45Hz, thus all is well.

 

So don't worry, be happy. : )

 

God bless you and your precious family - Langston

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I am not so sure if all normal radiator cone speakers are protected as described here. The fact that you don't hear deep bass from a small speaker doesn't mean that the excursion of the diaphragm doesn't take place.
Even if you don't destroy the bass driver yet, it produces more distortion and unwanted Doppler effects in the higher audible frequency range when it makes strong excursions in the deep bass where you can't hear it anymore.
This can be especially dangerous with bass reflex speakers if the cone below the tuned resonant frequency no longer has an air suspension that would brake the excursion of the cone.

If you want to enjoy the advantages of a subs, it makes sense that the bass cone of the speaker gets a lowcut. Modern small amplifiers such as the PowerNode from Bluesound automatically build in a low cut which you can select in frequency if you select the option with sub.

For normal listening levels nothing will happen to the speaker, just like without sub. But it is an advantage to use a low cut when using subs.

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11 hours ago, Langston said:

 

Somebody just woke me up with her snoring, so I'm going to tinker with this. I'm worse, but it doesn't wake me or her for some reason. : )

 

A low pass filter allows lower frequencies, a low cut filter (also called a high pass filter) blocks low frequencies. I assume the latter is what you are referring to when you're hoping that something in your system is disallowing music with frequency content less than your loudspeaker can properly reproduce.

 

Low cut filters are used on each passband (woofer, midrange, tweeter, etc.) of loudspeakers intended for concert production because those systems are driven near their physical limits (heat and excursion, or how far the driver is allowed to move). Low cut filters are also seen in home audio systems, but rarely for woofers because their physical limits are rarely approached, cost is much more of a factor and because these filters introduce phase errors that compromise the quality of low frequency sound if not done carefully. Low cut filters are used in home audio subwoofer systems that are expected to be driven to their limits.

 

The answer to your not-so-simple question, Part 1

It's physics, but it's not hard and wildly entertaining to nut cases like us, so hang in there. Of the two loudspeaker failure modes; over-heating and over-excursion, over-heating is by far the more frequent loudspeaker killer. In home audio this kind of heat build up during long-term, very loud music playback isn't likely as it would cause permanent damage with your neighbors quicker than your loudspeakers. BUT if your amplifier is large enough and you drop a needle on a record or crank the volume to 11 during movie explosions, you may cause permanent damage to the woofer due to over-excursion. This damage is extremely rare even after doing something dumb (personal knowledge borne of much experience). Why is damaging over-excursion so rare? Because the physics of moving coil loudspeaker systems limits excursion below the region where the loudspeaker can reproduce sound.

 

The answer to your not-so-simple question, Part 2

Your woofer can move only so far outward from rest, or inward from rest, before it is damaged. Your woofer also produces a range of frequencies, and as you go lower in frequency, it has to move further in and out to produce a constant sound pressure level (flat frequency response). It just so happens that a loudspeaker driver has to move four times further in and out as frequency reduces by half. This quadrupling of excursion to maintain flat sound pressure level or frequency response is a 12dB per octave increase in excursion. Say your loudspeaker is flat down to 45Hz, then rolls off at 12dB per octave under 45Hz. THAT MEANS THE WOOFER STOPS INCREASING EXCURSION UNDER 45Hz. Yea! Thus if your loudspeakers sound good at the volume you are playing, there's nothing bad being done to the woofer at frequencies less that what you are hearing. BTW, it's most likely that your loudspeaker system rolls off by at least 24dB per octave, thus excursion is actually reducing as frequency decreases under 45Hz, thus all is well.

 

So don't worry, be happy. : )

 

God bless you and your precious family - Langston

Thank you for the in-depth explanation. So in other words damage is highly unlikely unless I am playing at such unreasonably loud volumes. I think you're right in that I should just enjoy the speakers and not worry all too much about what 'could' happen. 

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6 hours ago, KT88 said:

I am not so sure if all normal radiator cone speakers are protected as described here. The fact that you don't hear deep bass from a small speaker doesn't mean that the excursion of the diaphragm doesn't take place.
Even if you don't destroy the bass driver yet, it produces more distortion and unwanted Doppler effects in the higher audible frequency range when it makes strong excursions in the deep bass where you can't hear it anymore.
This can be especially dangerous with bass reflex speakers if the cone below the tuned resonant frequency no longer has an air suspension that would brake the excursion of the cone.

If you want to enjoy the advantages of a subs, it makes sense that the bass cone of the speaker gets a lowcut. Modern small amplifiers such as the PowerNode from Bluesound automatically build in a low cut which you can select in frequency if you select the option with sub.

For normal listening levels nothing will happen to the speaker, just like without sub. But it is an advantage to use a low cut when using subs.

I saw that powernode version that had some bass management. Although the S-501 that I got is a great amp it doesn't offer that. So I will set the sub somewhere around 50-80hz and they will have to share that 45-80hz range of frequencies. I guess I will just make sure nothing is sounding 'off' or distorted and if it sounds fine it probably is fine. It is under warranty after all. Thanks for your input. 

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KT88 hits it on the technical side. 

Here's the easier explanation:

 

Those speakers are bass-reflex (ported).

They can only reproduce sound down to the port tuning frequency.

Any frequency below that will just end up flapping the speaker cones around with no resulting sound.

This flapping causes a great deal of modulation distortion in the frequencies the speaker can reproduce.

 

If you can, run a sub with those speakers, set to cross over at 60-100Hz. That will clean up a lot of intermodulation hash.

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23 minutes ago, DirtyErnie said:

KT88 hits it on the technical side. 

Here's the easier explanation:

 

Those speakers are bass-reflex (ported).

They can only reproduce sound down to the port tuning frequency.

Any frequency below that will just end up flapping the speaker cones around with no resulting sound.

This flapping causes a great deal of modulation distortion in the frequencies the speaker can reproduce.

 

If you can, run a sub with those speakers, set to cross over at 60-100Hz. That will clean up a lot of intermodulation hash.

Hey man, not sure if you were able to read all my stuff(I know its alot), but I don't have a way to set my crossover on my Yamaha S-501. My sub is in the mail, and it has its own crossover, but no way to prevent the speakers from playing full range. Any ideas? Or I am going to have to deal which this flapping/distortion you are talking about. I don't get why the didn't make the amp where if it recognized a sub was plugged in, it would only send 100hz and up to the mains since its sending 100hz and below to the 'sub-out'.

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