Hypex FA253 - Clipping (Woofer)

[fadihusseini]

Hi Everyone,

I need help please. I am using the Hypex FA253 plate amplifier which provides 250W for the woofer. The cabinet is circa 50L, woofer is SB Acoustics- Satori W024P-24 (9.5") rated Power Handling of 90W, coupled with a Passive Radiator also SB Acoustics SB29NRX2-00 (10") tuned at 25 Hz.

All of the DSP filters are cuts (no boosts) and a High Pass LR48 @25 HZ and a Low Pass LR48 to the Midrange. The Midrange is 2 Satori 5" drivered wired parallel, each have a rated power rating of 30W, so total summed @ 60 W.

I set the Hypex FA 253 soft clipper @ 180W for the woofer & 90W for the Midranges. When I raise the volume of the Hypex to -5DB, clipping signal starts. It seems it is the woofer because when I EQ the source the very low frequency (65 HZ), the clipping signal turns off.

Unfortunately, I don't have the actual impedance measuring equipment.

The source is Wiim Ultra streamer connected using SPDIF.

Anyone with a similar issue or any advise? The speakers will be used for small parties with house music dominated by bass.

Thank you in advance.

 

[staticV3]

Have you measured the FA253 output voltage to the woofer with a basic multimeter?

You can use e.g. REW Tone burst signals to get reliable readings w/o stressing the woofer much.

At what output voltage does the Hypex show clipping?

 

[fadihusseini]

Have you measured the FA253 output voltage to the woofer with a basic multimeter?

You can use e.g. REW Tone burst signals to get reliable readings w/o stressing the woofer much.

At what output voltage does the Hypex show clipping?

It's my first diy build; don't have the experience to do so, but can learn... any suggested guide or reading pls?

Really appreciate your reply

 

[staticV3]

It's my first diy build; don't have the experience to do so, but can learn... any suggested guide or reading pls?

not much to it honestly.

Set the Multimeter to V AC, ~200V range or thereabouts, turn on Max if your meter has it so that the display holds the highest measured voltage.

Put each probe to one of the output terminals on the FA253 or input terminals on the woofer.
Doesn't matter which probe goes to which terminal, just be careful that you do not touch both terminals with a single probe which would short them.

Here are some example parameters for REW's signal generator:


Start with low volume and creep your way up.

Also try varying the number of cycles. You want enough cycles that your DMM readings are stable, but not so many that you overstress the woofer.

Then increase the volume until you first see the Clipping indicator and note down the DMM's voltage reading.

Hypex specify 250W @4Ω, which equals 31.6V

 

[fadihusseini]

not much to it honestly.

Set the Multimeter to V AC, ~200V range or thereabouts, turn on Max if your meter has it so that the display holds the highest measured voltage.

Put each probe to one of the output terminals on the FA253 or input terminals on the woofer.
Doesn't matter which probe goes to which terminal, just be careful that you do not touch both terminals with a single probe which would short them.

Here are some example parameters for REW's signal generator:
View attachment 508663

Start with low volume and creep your way up.

Also try varying the number of cycles. You want enough cycles that your DMM readings are stable, but not so many that you overstress the woofer.

Then increase the volume until you first see the Clipping indicator and note down the DMM's voltage reading.

Hypex specify 250W @4Ω, which equals 31.6V

Thank you very much... will do so.

 

[fadihusseini]

not much to it honestly.

Set the Multimeter to V AC, ~200V range or thereabouts, turn on Max if your meter has it so that the display holds the highest measured voltage.

Put each probe to one of the output terminals on the FA253 or input terminals on the woofer.
Doesn't matter which probe goes to which terminal, just be careful that you do not touch both terminals with a single probe which would short them.

Here are some example parameters for REW's signal generator:
View attachment 508663

Start with low volume and creep your way up.

Also try varying the number of cycles. You want enough cycles that your DMM readings are stable, but not so many that you overstress the woofer.

Then increase the volume until you first see the Clipping indicator and note down the DMM's voltage reading.

Hypex specify 250W @4Ω, which equals 31.6V

Hi,

Pls forgive my ignorance in advance, i must be doing something wrong! I got the AstroAI M4K0R Digital Multimeter, and set it to AC volt testing.

I have the Hypex FA 253 soft clipper enabled @ 180 W, played music using the RCA connection from my laptop, increased the hypex volume to +5 till clipping started.

Afterwards, I set the Tone Burst on Rew as you suggested at cycles 10 for 60 HZ, started with a low volume and increaed the volume till -11 dBFS, the multimeter was getting a readings of circa 3.3 volts. When I increased the volume further, the multimeter increased to circa 4.0 volts and then immedialy jumped to a reading of 0.L (overload) though the hypex's was not indicating any clipping; i have the Oled Remote Screen which signals the clipping.

I tried increasing the cycle, tried to read up on the internet if the multimeter setup should be changed, but everything seems to be correct.

Or maybe, this explains what is happening? Would highly appreciate your guidance.

Concurrently, I reached out to SB Acoustics to see if they have any advise on the correct soft clipper parameter, their reply was "
" I am not familiar with the settings of the FA253.
Thermal power handling is rarely a problem. You should be looking at simulations to understand at what power levels the drivers (and passive) will reach maximum excursion and consider any settings in the amp to avoid mechanical overload of the drivers. This can be subsonic high pass filter, level protectors or maybe the amp has dynamic limiters.
WinISD and many other free software can model this."

I modeled my current system in WinISD assuming full power of 250W, and the following the results:

I also modeled changing the HP to 30Hz & adding a PEQ cut @ 43.5 HZ (Gain -4.60, Q 1.4) to keep the max excursion @ 8.5 mm:

Very sorry for the long post, and thank you in advance for taking your time to help....

 

[staticV3]

When I increased the volume further, the multimeter increased to circa 4.0 volts and then immedialy jumped to a reading of 0.L (overload)

This means that the voltage has exceeded the multimeter's currently selected 4.0V voltage range.

Set it to a higher voltage range (40V, 400V) and you can resume measuring.

 

[smygolf]

What does input / output the software say ?

Keep in mind that changes in winisd only counts if the speaker follows the simulation.
Best would be to measure the speaker.

I also have 253 to my LCR but are using analog in and PEQ + HPF/LPF - no issues even if i max the amps.

 

[DVDdoug]

I'd be inclined to trust the clipping indicator. Loud-deep bass or "realistic" bass that you can feel in your body can require LOTs of power and big woofers

I got the AstroAI M4K0R Digital Multimeter, and set it to AC volt testing.

Digital multimeters are meant for measuring constant voltages With audio they are unpredictable and unreliable. The inertia of an old-style analog meter movement is pretty-good at averaging-out the readings but for clipping you need to know the peaks. The digital meter MIGHT be averaging too but we usually don't know. The peaks can be 10 times the average depending on the program material.

But don't test with continuous high-power test-tones!!! A 90W speaker is designed for 90W on the program peaks. You can listen with short bursts (and maybe check the clipping indicator), then disconnect the speaker and you can measure the continuous voltage.

I have the Hypex FA 253 soft clipper enabled @ 180 W,

Also, soft-clipping (peak limiting) doesn't do much to protect the speaker because you still may have enough average-continuous power to burn-out the woofer. It's to "protect" the sound, making the distortion less-audible. That could be more dangerous if you don't hear the distortion so you turn it up, increasing the average.

and increaed the volume till -11 dBFS

There is no automatic calibration between digital, electrical, or acoustic dB levels. But an 11dB change in the digital level does translate to an 11dB change in SPL as long as you're not clipping or hitting the limits of the speaker.

 

[sigbergaudio]

The ohm/wattage setting on the limiter in Hypex works in mysterious ways when attempting to match it to the manufacturer specified limits of a driver.

The best would probably be to use a microphone and REW to measure distortion, and set the limiter at whatever you find to be reasonable maximum amount of distortion. For instance 10% THD. Note that the limiter itself introduces THD as well. So measure without the limiter first to figure out the maximum level you want, than adjust the limiter until it limits the speaker before it reaches that level.

 

[fadihusseini]

This means that the voltage has exceeded the multimeter's currently selected 4.0V voltage range.

Set it to a higher voltage range (40V, 400V) and you can resume measuring.

I tested the multimeter on electrical voltage, and reads 230V correctly.... No range configuration parameter.... Reading jumps from ~4 volt to 0.L

 

[fadihusseini]

What does input / output the software say ?
View attachment 509618

Keep in mind that changes in winisd only counts if the speaker follows the simulation.
Best would be to measure the speaker.

I also have 253 to my LCR but are using analog in and PEQ + HPF/LPF - no issues even if i max the amps.

Vu meters are normal. I have been using digital SPDIF in... Should test RCA, which (I think) has a lower dB input than the RCA... I am preferring to have all digital in to avoid the multiple conversions (DAC & ADC) along with depending Hypex's DAC quality

 

[staticV3]

I tested the multimeter on electrical voltage, and reads 230V correctly.... No range configuration parameter.... Reading jumps from ~4 volt to 0.L

Turn off Auto and set it manually to 40V.

The Burst tone likely messes up the Auto range.

 

[fadihusseini]

I'd be inclined to trust the clipping indicator. Loud-deep bass or "realistic" bass that you can feel in your body can require LOTs of power and big woofers


Digital multimeters are meant for measuring constant voltages With audio they are unpredictable and unreliable. The inertia of an old-style analog meter movement is pretty-good at averaging-out the readings but for clipping you need to know the peaks. The digital meter MIGHT be averaging too but we usually don't know. The peaks can be 10 times the average depending on the program material.

But don't test with continuous high-power test-tones!!! A 90W speaker is designed for 90W on the program peaks. You can listen with short bursts (and maybe check the clipping indicator), then disconnect the speaker and you can measure the continuous voltage.


Also, soft-clipping (peak limiting) doesn't do much to protect the speaker because you still may have enough average-continuous power to burn-out the woofer. It's to "protect" the sound, making the distortion less-audible. That could be more dangerous if you don't hear the distortion so you turn it up, increasing the average.


There is no automatic calibration between digital, electrical, or acoustic dB levels. But an 11dB change in the digital level does translate to an 11dB change in SPL as long as you're not clipping or hitting the limits of the speaker.

I am starting to think that the digital multimeter is having issues with the readings, or prbably the reading jumping from ~4volt to 0.L is due to the amp clipping prior to the Oled screen starts indicating so... Maybe I should get an analgue reading.

You mentioned a 90W speaker is designed for 90W on program peak. I am still trying to get my head around power rating, and thus reached out to SB Acoustics. Their reply seem to have indicated to focus more on limiting excursion rather than limiting power.

I want to follow the clipping indicator, but not sure what would be correct parameter. Should I set it at 180W, or 220W including the WinISD excursion simulation (i.e. have a HP @30 HZ and a PEQ Cut?). At 90W, the volume is relatively quite low!

My aim is to get the max possible, and I am aware that my amplifiers are more powerful than the speaker drivers.

 

[fadihusseini]

The ohm/wattage setting on the limiter in Hypex works in mysterious ways when attempting to match it to the manufacturer specified limits of a driver.

The best would probably be to use a microphone and REW to measure distortion, and set the limiter at whatever you find to be reasonable maximum amount of distortion. For instance 10% THD. Note that the limiter itself introduces THD as well. So measure without the limiter first to figure out the maximum level you want, than adjust the limiter until it limits the speaker before it reaches that level.

Would very much appreciate any guides about these measurements? This is my first build...

Thank you in advance

 

[Wolf11Man]

The Multimeter reading will not help you, you need experience if you want to do a usefull interpretation of what it shows. You can not get this experience by reading a few well meant posts in a forum. You may need years or even decades to become a designer of well working speakers. Sorry, I know you don't want to read this.

You should measure what your build does by using some program like REW and compare it to your simulation. This is no matter of cost, you only need a resistor and the urge to learn something. You do NOT need a microfone! In fact this would only give random results for you.
The impedance measurements and the different tone generators (sweep, constant frequency) are all you need.
As long as you don't measure the impedance it is all speculation.

 

[-Matt-]

I tested the multimeter on electrical voltage, and reads 230V correctly.... No range configuration parameter.... Reading jumps from ~4 volt to 0.L

It is a bit concerning that someone who is demonstrating such incompetence at using a multimeter is attempting to measure mains voltages. @fadihusseini you need to understand the risks you are taking and make an honest assessment if what you are attempting is within your capabilities.

Whilst @staticV3 is giving good advice, sometimes a little knowledge can be dangerous in the wrong hands.

 

[fadihusseini]

It is a bit concerning that someone who is demonstrating such incompetence at using a multimeter is attempting to measure mains voltages. @fadihusseini you need to understand the risks you are taking and make an honest assessment if what you are attempting is within your capabilities.

Whilst @staticV3 is giving good advice, sometimes a little knowledge can be dangerous in the wrong hands.

It would be absolutely great if you have any constructive suggestion. If not, I would suggest that you direct your "addiction to fun and learning" somewhere else!

The electricty voltage was to test if the multimeter have range limitations, and was done safely!

It seems that you have nothing to do in life except for trying to troll people that are actually trying to learn. Go fish somehwere else.

 

[sigbergaudio]

Would very much appreciate any guides about these measurements? This is my first build...

Thank you in advance

Have you measured the frequency response of the speakers with REW (or some other software)?

 

[staticV3]

I am starting to think that the digital multimeter is having issues with the readings, or prbably the reading jumping from ~4volt to 0.L is due to the amp clipping prior to the Oled screen starts indicating so... Maybe I should get an analgue reading.

0.L has nothing to do with the Amp clipping.

All it tells you is that the voltage present at the DMM's probes is exceeding its currently used voltage range.

This is not surprising when measuring a fast tone burst using the DMM's Autorange function, which expects a stable signal.

To fix it, set the DMM manually to 40V range. It should now read the proper voltage.