Can frequency extremes do any strain?

[stereoman]

Hello all audiophiles. Is this really a myth or frequency extremes including ultrafrequency above 20Khz ( in moderate volume level ) contribute to any slow speaker damage ( woofer, tweeter ) ? I veer on myth side but I wonder what you think.

For example:

https://www.youtube.com/watch?v=qNf9nzvnd1k

 

[daytona600]

20khz nothing higher with digital CD redbook , DSD & 24/96khz digital get get into ultrasonics

1970s analogue can get to 122khz Studer tape machine / Ortofon cutting heads / Neumann VMS-70 lathe.

only a bat can hear 100khz but music does contain ultrahigh fundamentals on cymbals , muted horns etc

or add a super-tweeter for 20khz + some reach 50/100khz

 

[stereoman]

20khz nothing higher with digital CD redbook , DSD & 24/96khz digital get get into ultrasonics

1970s analogue can get to 122khz Studer tape machine / Ortofon cutting heads / Neumann VMS-70 lathe.

only a bat can hear 100khz but music does contain ultrahigh fundamentals on cymbals , muted horns etc

or add a super-tweeter for 20khz + some reach 50/100khz

Thanks a lot. But I more meant whether subsonic and ultrasonic frequencies played at moderate (unheard and played at not loud levels) can damage the woofer and tweeter anyway or not at all as they are cut out by inbuilt filters.

 

[Alantiggger]

Hahahahaha, Brilliant stuff.

 

[Alantiggger]

Hehe , you are at it eh ?

Not a Chance of damage, how COULD it damage ?

 

[stereoman]

Hehe , you are at it eh ?

Not a Chance of damage, how COULD it damage ?

Very funny I know. I also think it is a myth. I meant by woofer excursions

in area 10Hz up to 40Hz ??? Why do subwoofer

and some amps like Accuphase have subsonic filters then ?

 

[davedotco]

Hehe , you are at it eh ?

Not a Chance of damage, how COULD it damage ?

Very funny I know. I also think it is a myth. I meant by woofer excursions

in area 10Hz up to 40Hz ??? Why do subwoofer

and some amps like Accuphase have subsonic filters then ?

It is perfectly possible to damage a woofer with subsonics, particularly with modern equipment. Here's why...

This is a problem with turntable based systems and the subsonic noise they produce, mostly record warp or low frequency, structural born vibration.

This can be a problem for several reasons, most people use relatively low cost players and few use proper supports, sub sonic vibrations are common. Most modern loudpeakers are ported, often tuned in the range 40 to 80Hz, what is not so well known is that while the loading on the bass driver is optimum at the tuned frequency, the loading is minimal an octave below this (anti-phase), ie nothing to restrict cone movement. At best, this impacts on bass quality, but there is more to it than that.

If in a system any of this noise coincides with the anti-phase frequency, the cone excursions can be alarming and in some cases sufficient to 'pop' the voicecoil out of the front of the magnet, usually fatal. Even in less severe cases, the coil can overheat and blow due to spending too much time outside the magnet gap and losing it's cooling effect.

This is an even bigger problem with many modern amps/phono stages which do not have proper subsonic filtering, not usually a problem with digital sources, but with vinyl it is a real issue.

 

[MajorFubar]

^^^correct, it's why most amps back in the day had subsonic filters. I've 'ripped' about 20 LPs to my NAS to go with the CDs in my iTunes library, and the template I've made for recording them has a steep 48dB/oct high-pass filter at 20Hz for just this reason. I probably should raise it to 30Hz, but I kid myself that amongst the vinyl roar and LF rumble there's sometimes potentially something worth recording between 20Hz-30Hz.

 

[CnoEvil]

As said above - Back in the day, when TT was the main Source, Amps had Rumble Filters and Sealed Speakers were the norm.

In modern AV action films, if the full range is sent, at very loud volumes, to small speakers not designed to handle it...then damage could ensue.

That is why it's better to let the Sub carry the burdon and not run at full range with small speakers, especially if you like to listen at reference levels.

 

[paulkebab]

I had used to set the cones on my Wharfedale E70's moving around 8-10Hz on the 'no music' parts, not much volume required and quite scary at the time. Fortunately CD was becoming affordable so I was glad to get rid.

 

[davedotco]

I had used to set the cones on my Wharfedale E70's moving around 8-10Hz on the 'no music' parts, not much volume required and quite scary at the time. Fortunately CD was becoming affordable so I was glad to get rid.

At those frequencies you are in arm/cartridge resonance territory, really should not be allowed through to the speaker.

Incompedent design in either the amp or phono stage. Very common in line level only amplifiers which is bad enough but for a phono stage to pass these frequencies is inexcuseable.

 

[paulkebab]

I can't remember 100% but I think at the time I had an Aiwa 8300 amp with a Technics SL6 or 7 fully auto turntable. As I said, only this piece of vinyl ( Rush - Moving Pictures ) had this issue, definitely didn't ​ make me smile but the album was and still is awesome. Maybe I should have returned it but things moved on.

 

[MajorFubar]

worthwhile noting that dynamic range can be a killer, too. I remember the warnings on Telarc CDs lol. Less of an issue these days seeing it's all about making a flat line with the average loudness whacked up to -6dB LUFS

 

[stereoman]

I am extremely delightful with your - as usual - profi answers but actually can someone respond a bit more directly to the point or the gist ? I mean if you have a pair of loudspeakers without the sub and play through them ( but ONLY at 10 o'clock moderate volume level ) - without the subsonic filter - 5Hz to 30Hz and 18Khz to 25 Khz sound frequency ranges - does it strain the coils, woofers, tweeters etc in a long run ? Or are the speakers totally unaffected ? From what I read and understand is that you meant that it can be indeed detrimental or only when playing such extremes loud ?

 

[davedotco]

I am extremely delightful with your - as usual - profi answers but actually can someone respond a bit more directly to the point or the gist ? I mean if you have a pair of loudspeakers without the sub and play through them ( but ONLY at 10 o'clock moderate volume level ) - without the subsonic filter - 5Hz to 30Hz and 18Khz to 25 Khz sound frequency ranges - does it strain the coils, woofers, tweeters etc in a long run ? Or are the speakers totally unaffected ? From what I read and understand is that you meant that it can be indeed detrimental or only when playing such extremes loud ?

The kind of bass cone excusions that I described in an earlier post can certainly destroy bass drivers, the usual scenario is some sort of structural born vibration, footfall for example, causing excessive cone excursions at frequencies where the loading on the bass cone is minimal. This can 'pop' the bass driver as described above or cause overheating of the voicecoil due to the loss of cooling when the coil is actually out of the gap for substantial periods of time. Moderate levels are more than sufficient to cause this sort of damage.

Supersonic frequencies can be just as dangerous, usually caused by amplifier oscillations or RFI, these frequencies are neither audible nor visible in terms of movement of the tweeter diaphragm. Fortunately, with modern designs, this is far less common than in the past, though it still occurs and is the most likely cause of blown tweeters as the noise can not be heard.

 

[stereoman]

I am extremely delightful with your - as usual - profi answers but actually can someone respond a bit more directly to the point or the gist ? I mean if you have a pair of loudspeakers without the sub and play through them ( but ONLY at 10 o'clock moderate volume level ) - without the subsonic filter - 5Hz to 30Hz and 18Khz to 25 Khz sound frequency ranges - does it strain the coils, woofers, tweeters etc in a long run ? Or are the speakers totally unaffected ? From what I read and understand is that you meant that it can be indeed detrimental or only when playing such extremes loud ?

The kind of bass cone excusions that I described in an earlier post can certainly destroy bass drivers, the usual scenario is some sort of structural born vibration, footfall for example, causing excessive cone excursions at frequencies where the loading on the bass cone is minimal. This can 'pop' the bass driver as described above or cause overheating of the voicecoil due to the loss of cooling when the coil is actually out of the gap for substantial periods of time. Moderate levels are more than sufficient to cause this sort of damage.

Supersonic frequencies can be just as dangerous, usually caused by amplifier oscillations or RFI, these frequencies are neither audible nor visible in terms of movement of the tweeter diaphragm. Fortunately, with modern designs, this is far less common than in the past, though it still occurs and is the most likely cause of blown tweeters as the noise can not be heard.

Great , thank you and you guys*good* !

 

[andyjm]

I am extremely delightful with your - as usual - profi answers but actually can someone respond a bit more directly to the point or the gist ? I mean if you have a pair of loudspeakers without the sub and play through them ( but ONLY at 10 o'clock moderate volume level ) - without the subsonic filter - 5Hz to 30Hz and 18Khz to 25 Khz sound frequency ranges - does it strain the coils, woofers, tweeters etc in a long run ? Or are the speakers totally unaffected ? From what I read and understand is that you meant that it can be indeed detrimental or only when playing such extremes loud ?

The subsonic wild excursions of bass drivers can occur at even moderate listening levels if you are using vinyl. Back in the day, amps either had subsonic filters on their inputs, or were AC coupled and then the freqency response of the amp tailed off toward LF anyway. These days with amps having 'DC to daylight' performance, subsonic filters are a must for vinyl.

Along with its many other vices, this is a particular problem for vinyl because of RIAA equalisation. LF is attenuated when the disc is cut, and boosted when it is played back. Unfortunately, this means any rumble and the effect of record warps are also boosted - by up to as much as 20dB. So a warped record can cause silent but wild excursions, which as pointed out above can cause the voicecoil to overextend with bad consequences for the speaker.

 

[davedotco]

I am extremely delightful with your - as usual - profi answers but actually can someone respond a bit more directly to the point or the gist ? I mean if you have a pair of loudspeakers without the sub and play through them ( but ONLY at 10 o'clock moderate volume level ) - without the subsonic filter - 5Hz to 30Hz and 18Khz to 25 Khz sound frequency ranges - does it strain the coils, woofers, tweeters etc in a long run ? Or are the speakers totally unaffected ? From what I read and understand is that you meant that it can be indeed detrimental or only when playing such extremes loud ?

The subsonic wild excursions of bass drivers can occur at even moderate listening levels if you are using vinyl. Back in the day, amps either had subsonic filters on their inputs, or were AC coupled and then the freqency response of the amp tailed off toward LF anyway. These days with amps having 'DC to daylight' performance, subsonic filters are a must for vinyl.

Along with its many other vices, this is a particular problem for vinyl because of RIAA equalisation. LF is attenuated when the disc is cut, and boosted when it is played back. Unfortunately, this means any rumble and the effect of record warps are also boosted - by up to as much as 20dB. So a warped record can cause silent but wild excursions, which as pointed out above can cause the voicecoil to overextend with bad consequences for the speaker.

Add this to the noise transmitted by structural vibrations and you can see why controlling sub bass frequencies is important.

RIAA equalisation is a ******, a very necessary evil. With an otherwise flat amplifier, warp frequencies can easily be 5-6dB higher than bass notes in the 70-80Hz region. The excessive bandwidth is so unnecessary, most mainstream LPs filter the music signal below 70Hz, 12dB/octave is not unusual, so there is prescious little musical information below about 50hz. There are a few exceptions of course but mostly it is just noise.