Calculating available headroom from using high-pass

[Endymion Joshi-Godrez]

Im likely to purchase either a pair of Genelec 8351b or 61a SAM systems in the near future. I will be more honest than most to say that i listen way too loud. Somewhere around 90db with most music, but metal related is most likely around 100 nominal. Going by Genelecs SPL chart https://www.genelec.com/correct-monitors the only monitor at 2.5m listening distance that would be appropriate is the 8361a. However, there are 2 problems with this approach:

1. They only measure SPL as a frequency band starting at 100hz
2. I plan in any case to high-pass the SAM motitor at 50 or 60hz with one of their subwoofers (either 7360 or 7370, feel free to recommend me)

The discrepancy this creates is both; I dont know how loud any monitor can play over its entire frequency spectrum since we a less sensitive to frequencies below 100hz than above (please let me know if this point is irrelevant in this example), and i dont know how to calculate how much more headroom i would get by high-passing the monitors.

Linkwitz believed that you need 4 times more power for the same SPL for each octave you descend. Does this mean the bass amp of the speaker (remember all genelec models use separate amps for each driver) needs only 25% of the power it would of needed if it has -3db shelf at 32hz, but now being high-passed at 60hz (a full octave) instead at the same SPL? If thats true, is there any way to calculate the available SPL without knowing the sensitivity of the driver? I'm aware that the driver itself has a maximum THD, but I know the one's monitors can be played extremely loud (more than 120db), when passed at a much higher frequency with the w371, for which i would never play a speaker so loud. This is all to calculate if i should either purchase a 61a or find that i can save a bit to get a 51b and still have adequate headroom with a high-pass.

Im aware that i need to contact genelec themselves, but this comment is a complete mess (sorry about that), so I would appreciate if people could give me any explanation they have, so i can format it to them more appropriately. Thank you.

 

[Endymion Joshi-Godrez]

Also, don't recommend me the w371. It is universes beyond my price range.

 

[Joachim Herbert]

I know you know.

If you intend to listen that loud over longer periods of time, it does not matter what you use to listen your music to.

Your hearing will be damaged in no time at all.

So the good news is that playing loud is the only condition your speakers must meet. You will not be able to appreciate the difference after a year or so.

Loud Noises Damage Hearing

Noisy exposure away from the job can damage hearing just as much as working in a noisy place. Learn more.

www.cdc.gov

 

[sarumbear]

Im likely to purchase either a pair of Genelec 8351b or 61a SAM systems in the near future. I will be more honest than most to say that i listen way too loud. Somewhere around 90db with most music, but metal related is most likely around 100 nominal. Going by Genelecs SPL chart https://www.genelec.com/correct-monitors the only monitor at 2.5m listening distance that would be appropriate is the 8361a. However, there are 2 problems with this approach:

1. They only measure SPL as a frequency band starting at 100hz
2. I plan in any case to high-pass the SAM motitor at 50 or 60hz with one of their subwoofers (either 7360 or 7370, feel free to recommend me)

The discrepancy this creates is both; I dont know how loud any monitor can play over its entire frequency spectrum since we a less sensitive to frequencies below 100hz than above (please let me know if this point is irrelevant in this example), and i dont know how to calculate how much more headroom i would get by high-passing the monitors.

Linkwitz believed that you need 4 times more power for the same SPL for each octave you descend. Does this mean the bass amp of the speaker (remember all genelec models use separate amps for each driver) needs only 25% of the power it would of needed if it has -3db shelf at 32hz, but now being high-passed at 60hz (a full octave) instead at the same SPL? If thats true, is there any way to calculate the available SPL without knowing the sensitivity of the driver? I'm aware that the driver itself has a maximum THD, but I know the one's monitors can be played extremely loud (more than 120db), when passed at a much higher frequency with the w371, for which i would never play a speaker so loud. This is all to calculate if i should either purchase a 61a or find that i can save a bit to get a 51b and still have adequate headroom with a high-pass.

Im aware that i need to contact genelec themselves, but this comment is a complete mess (sorry about that), so I would appreciate if people could give me any explanation they have, so i can format it to them more appropriately. Thank you.

You will be spending a deal of money on either model. Demo them before buying. Buying a speaker is like buying a pair of shoes. You either try them at a shop or buy them online with a free return option.

I personally would buy the 61 if continuous high SPL is a requirement.

 

[RayDunzl]

Modifying the signal can have unintended results:

Daft Punk Random Access Memories Track 2

Top: Shows the limits of the recording - without high-pass
Bottom: Shows clipping introduced when the low bass is removed.

Analysis: Extreme engineering of the signal by the producers. High frequencis "ride" the bass frequencies, remove the bass, and their "control" is upset, with approximately +6dB clips.

The original waveform:

No clipping as defined by two full scale samples in a row. There are plenty of full-scale single samples, though.

The 60Hz 24dB/octave High Pass applied, and the clipping analysis:

Uh, "many".

 

[Endymion Joshi-Godrez]

I know you know.

If you intend to listen that loud over longer periods of time, it does not matter what you use to listen your music to.

Your hearing will be damaged in no time at all.

So the good news is that playing loud is the only condition your speakers must meet. You will not be able to appreciate the difference after a year or so.

Loud Noises Damage Hearing

Noisy exposure away from the job can damage hearing just as much as working in a noisy place. Learn more.

www.cdc.gov

Thank you, but 100db is just fine and i will not be taking your advice, just like i dont take advice to eat chicken when it is 165f cardboard. In reality its simply not true.

 

[Endymion Joshi-Godrez]

Modifying the signal can have unintended results:

Daft Punk Random Access Memories Track 2

Top: Shows the limits of the recording - without high-pass
Bottom: Shows clipping introduced when the low bass is removed.

Analysis: Extreme engineering of the signal by the producers. High frequencis "ride" the bass frequencies, remove the bass, and their "control" is upset, with approximately +6dB clips.

View attachment 278121


The original waveform:

View attachment 278122

Not sure why you are telling me this. Genelec says themselves that you can high-pass their speakers to get better spl. They are designed to be high-passed using their GLM software. The One's are rated way past 120db. Why are you telling me this?

 

[Endymion Joshi-Godrez]

You will be spending a deal of money on either model. Demo them before buying. Buying a speaker is like buying a pair of shoes. You either try them at a shop or buy them online with a free return option.

I personally would buy the 61 if continuous high SPL is a requirement.

No, im not doing that. One because i cant afford both simultaneously. 2. Because the GLM software takes a long time to set up and calibrate each one, and 3. Because they are both over 25kg for each speaker. I don't have a lift, and i live on the 5th floor. If i wanted to demo both of them, then i wouldn't be asking for advice.

 

[RayDunzl]

Why are you telling me this?

Because you asked.

Have a nice day

 

[LTig]

Not sure why you are telling me this. Genelec says themselves that you can high-pass their speakers to get better spl. They are designed to be high-passed using their GLM software. The One's are rated way past 120db. Why are you telling me this?

He tells you that removing the lows may indeed lead to peaks in the highs which are higher than with the lows, instead of lower what one would assume.

 

[fineMen]

... Genelec ... metal related is most likely around 100 nominal ...
The discrepancy this creates is both; I dont know how loud any monitor can play ...

Genelec are not designed for that, that simple. What you want is either a cinema speaker or a usually sofit mounted main monitor for bigger presentations, 50k$+

Linkwitz believed that you need 4 times more power for the same SPL for each octave ...

You got it wrong, if you believe you've got it right. Linkwitz never addressed such calculations that you are after.

Im aware that i need to contact genelec themselves, ...

Please do so. I'm sure they will make sense of it, see above. Maybe they recommend some hearing protection with their product.

I'm pretty much sure that you are foremost aware of the inherent contradiction in your request
In general I wonder why people are willing to spend multiple tens of kilodollars on something not really needed, but remain reluctant to hire a real consultant

 

[Endymion Joshi-Godrez]

Because you asked.

Have a nice day

View attachment 278125

I did NOT ask for you to tell me if they would clip. So no, i didnt ask.

 

[Endymion Joshi-Godrez]

Genelec are not designed for that, that simple. What you want is either a cinema speaker or a usually sofit mounted main monitor for bigger presentations, 50k$+

You got it wrong, if you believe you've got it right. Linkwitz never addressed such calculations that you are after.

Please do so. I'm sure they will make sense of it, see above. Maybe they recommend some hearing protection with their product.

I'm pretty much sure that you are foremost aware of the inherent contradiction in your request
In general I wonder why people are willing to spend multiple tens of kilodollars on something not really needed, but remain reluctant to hire a real consultant

Maybe you need to go outside. This behaviour isnt acceptable in regards to my comment. Try to develop some social understanding.

 

[fineMen]

Maybe you need to go outside. This behaviour isnt acceptable in regards to my comment. Try to develop some social understanding.

...
...

I did NOT ask for you to tell me if they would clip. So no, i didnt ask.

What you may not know is "metal" spectral distribution. I don't know of any "metal" recording that would comprise significant deep bass. Home cinema, yeah, Apollo 13. It's fun to risk a marriage on that single movie's soundtrack. Buying a sub worth a Corvette ... which is louder.

In short, get yourself a real consultant in, considering the cost and unclear needs, who has planned the inventory for at least some pro/ studios already. That person might be able to handle your entitled attitude also.

 

[Endymion Joshi-Godrez]

Again, guys. The GLM software is designed so you high-pass the SAMs to the SAM subwoofer. They use their own filters to do so. The w371 is designed to increase SPL of the SAM monitors. They say this in the video promoting it. I dont need your advice on how to use Genelec products, only my question. Thank you.

 

[Endymion Joshi-Godrez]

...
...

What you may not know is "metal" spectral distribution. I don't know of any "metal" recording that would comprise significant deep bass. Home cinema, yeah, Apollo 13. It's fun to risk a marriage on that single movie's soundtrack. Buying a sub worth a Corvette ... which is louder.

In short, get yourself a real consultant in, considering the cost and unclear needs, who has planned the inventory for at least some pro/ studios already. That person might be able to handle your entitled attitude also.

So you're saying everyone here will be completely useless? Fair enough.

 

[NTK]

Maybe you need to go outside. This behaviour isnt acceptable in regards to my comment. Try to develop some social understanding.

Here is someone who lives on the 5th floor, most likely in a multi-tenant building, want to "enjoy" listening at 100 dB SPL, and tells other to have social understanding.

 

[Endymion Joshi-Godrez]

Alright, i guess no one here has anyway calculating that.

 

[Endymion Joshi-Godrez]

Here is someone who lives on the 5th floor, most likely in a multi-tenant building, want to "enjoy" listening at 100 dB SPL, and tells other to have social understanding.

Do you know what my appartement looks like, or its complex? I've lived here for 6 years and had my speakers playing at that volume for every single one of those years. Try to think before you speak.

 

[Grotti]

The 8351 is simply the wrong speaker for your needs. With or without a high pass. Period.