[Marius]

HI James,


Ive checked all manuals/documentation on the 10bsub, but am not able to find an explanation in regular english... of the workings of the high and low pass db slope switches.


Could you please explain what happens exactly?
Ive set my low pass to 90 and highpass to 80, aiming at having my sub take over the lows from my ESL's and easy the latter from working to hard in the lower frequencies. Works wonders. Still i have 2 audible dips (still working out at which frequencies exactly), and like to experiment further with the 10bsub.


Setting these db switches does what precisely ? And when. I presume they change the DB at the set crossover Frequency? Can the 10bsub set the Sub at + db and the ESL at - db?


It says 6, 12 and 18 db / oct. Confuses me a bit: does it not only work at the set crossover frequency, but on all octaves?


Please clarify for me.


Marius

[James Tanner]

HI James,


Ive checked all manuals/documentation on the 10bsub, but am not able to find an explanation in regular english... of the workings of the high and low pass db slope switches.


Could you please explain what happens exactly?
Ive set my low pass to 90 and highpass to 80, aiming at having my sub take over the lows from my ESL's and easy the latter from working to hard in the lower frequencies. Works wonders. Still i have 2 audible dips (still working out at which frequencies exactly), and like to experiment further with the 10bsub.


Setting these db switches does what precisely ? And when. I presume they change the DB at the set crossover Frequency? Can the 10bsub set the Sub at + db and the ESL at - db?


It says 6, 12 and 18 db / oct. Confuses me a bit: does it not only work at the set crossover frequency, but on all octaves?


Please clarify for me.


Marius

Hi Marius

The 10B Sub uses Butterworth  filters so the crossover point you choose means the amplitude is down 3B at that point. So if you have the Low Pass at 80Hz then the Subwoofer is rolling off at 80 Hz at the Slope you choose - either 6, 12 or 18dB per octave.  So at 160Hz (80 x 2) the sub is down ion level 18dB.

On the High Pass if set at 80Hz the Main speakers are rolling off at 80Hz and are also down 3dB at that point and again the slope you set (6,12 0r 18) determines how quickly the Mains roll off.

So if you want to 'stagger' or 'overlap' the crossover points you can select different frequencies on the Low Pass and High Pass as well as different slopes.

james

[Marius]

HI James,
Thanks!


Am i correct assuming that in order to have a flat Frequency response, one must overlap High and Low Pass? In order to relieve my ESLs at 80 hz, do i have to set high pass at 90 to be rolled off at 80, and set low pass at 70 to take over going down from there, but rolling off upwards?


And then finetune with the db sliders?


Marius

[James Tanner]

HI James,
Thanks!


Am i correct assuming that in order to have a flat Frequency response, one must overlap High and Low Pass? In order to relieve my ESLs at 80 hz, do i have to set high pass at 90 to be rolled off at 80, and set low pass at 70 to take over going down from there, but rolling off upwards?


And then finetune with the db sliders?


Marius

No do not overlap if you want a flat frequency response.  Set the Low Pass and High Pass at the same frequency. 

When I had the Quads I used 60-80Hz (depending on the room) and both slopes at 18dB per octave.  Get the Woofer out as soon as you can so the lowest frequency that will work and 18dB on the lowpass.  On the high pass play with 18 and then 6dB.  When you change from 6 to 12 to 18dB you are shifting the Phase at the crossover point  by 90 degrees with each change so you are listening for what slope integrates the best between the Quads and the Subs.

james

[Marius]

thats what i had before (at 80z) but because you spoke about both rolling off at that frequency I figured that would cause a dip. Forgot for a moment they are added, thus equating to a straight frequency response. If adjusted correctly with the db switches of course...


Now testing again, best results sofar with crossover set at 60 (70 equally well, but id like the Quads to play as far down as possible without forcing them too much) lowpass slopes at 18db and highpass at 12. highpass level set at -2.  Gives a rather flat response (on the ear that is) .


Tested from the couch through bdp1's shairplay service! Thank you sir!


Thanks James.


 

No do not overlap if you want a flat frequency response.  Set the Low Pass and High Pass at the same frequency. 

james

[Marius]

James,


Talking about flat frequency response all over the 20-20khz spread, let me ask you this.


On the ear i have a very acceptable frequency response, with the lower bass (going down from 50 hz or so) not being to overwhelming. Metering this with an spl shows that the bass is very much softer, less than 20 db or less, going down to much less along the 20 hz region. above the 50 hz level i meter a consistent 50 db (+ or -).


If i turn up the bass ( i can do so, my Rel uses but a fraction of its power now) i can adjust the db metering, and thus result in a flatter response. But the music gets an overload of bass, which sounds horrible of course. Cant be right.


Which makes me wonder whether a straight frequency response is what i'm looking for in the first place...


Something along the lines of lower tones have a different impact than higher tones, not only to be measured in Db's?


Hope i made myself clear here, if not please try to make sense of it


Marius

[James Tanner]

James,


Talking about flat frequency response all over the 20-20khz spread, let me ask you this.


On the ear i have a very acceptable frequency response, with the lower bass (going down from 50 hz or so) not being to overwhelming. Metering this with an spl shows that the bass is very much softer, less than 20 db or less, going down to much less along the 20 hz region. above the 50 hz level i meter a consistent 50 db (+ or -).


If i turn up the bass ( ic an do so, my Rel uses but a fraction of its power now) i can adjust the db metering, and thus result in a flatter response. But the music gets an overload of bass, which sounds horrible of course. Cant be right.


Which makes me wonder whether a straight frequency response is what i'm looking for in the first place...


Something along the lines of lower tones have a different impact than higher tones, not only to be measured in Db's?


Hope i made myself clear here, if not please try to make sense of it


Marius

Definitely trust your ear !!!!   Also DB meters can loose a lot of sensitivity (accuracy) at low frequencies based on C curve or B curve settings etc.

james

[ragg987]

Humans do not hear sound equally. We are best "tuned" to midrange and at the extremes of bass and treble it will sound quieter even though a SPL would show it as flat.

Agree trust your ears - there other factors at those low frequencies like the SPL meter's frequency range and accuracy, positioning the SPL in nulls or peaks within the room.

One other factor - it may also depend on what level of bass you are used to hearing. In the old days when broadcast radio changed from MW (or AM) to FM, people used to complain that FM sounded thin. In fact they were so used to hearing the narrow frequency range from MW that the wider range available in FM was alien...

[Marius]

Humans do not hear sound equally. We are best "tuned" to midrange and at the extremes of bass and treble it will sound quieter even though a SPL would show it as flat.

Agree trust your ears - there other factors at those low frequencies like the SPL meter's frequency range and accuracy, positioning the SPL in nulls or peaks within the room.

One other factor - it may also depend on what level of bass you are used to hearing. In the old days when broadcast radio changed from MW (or AM) to FM, people used to complain that FM sounded thin. In fact they were so used to hearing the narrow frequency range from MW that the wider range available in FM was alien...

check.


it's as mr Linkwitz says: What you hear is not the air pressure variation in itself but what has drawn your attention
in the two streams of superimposed air pressure variations at your eardrums
An acoustic event has dimensions of Time, Tone, Loudness and Space

[werd]

Definitely trust your ear !!!!   Also DB meters can loose a lot of sensitivity (accuracy) at low frequencies based on C curve or B curve settings etc.

james

That sir is an understatement.   

[werd]

James,


Talking about flat frequency response all over the 20-20khz spread, let me ask you this.


On the ear i have a very acceptable frequency response, with the lower bass (going down from 50 hz or so) not being to overwhelming. Metering this with an spl shows that the bass is very much softer, less than 20 db or less, going down to much less along the 20 hz region. above the 50 hz level i meter a consistent 50 db (+ or -).
If i turn up the bass ( i can do so, my Rel uses but a fraction of its power now) i can adjust the db metering, and thus result in a flatter response. But the music gets an overload of bass, which sounds horrible of course. Cant be right.



Which makes me wonder whether a straight frequency response is what i'm looking for in the first place..
Something along the lines of lower tones have a different impact than higher tones, not only to be measured in Db


Hope i made myself clear here, if not please try to make sense of it



Marius.

What you are asking is directly related to the Fletcher Munson Bass curves https://en.m.wikipedia.org/wiki/Fletcher%E2%80%93Munson_curves

There are 2 distinct goals with sub placement.  You place subs for resolution and you place subs for room ambience. Room ambience exist under the Fletcher Munson curve and sweetpot resolution exists at a point over the curve. When you raise the
volume to read a flat signal you are basicaly raising the sub volume largely below the Munson curve. This lights ups the bass
 nodes in your room and starts infecting the resolution with boomy bass.
 
Subs working  for resolution are best raised (off the floor) and forward sitting in the sweetspot. Subs for room ambience are best placed on the floor behind the listener. This avoids the problems of multiple subs operating in a fashion that will raise bass boom.  I would be looking for flat bass response on the forward raised sub and not so much on a rear ambient sub.

[Marius]

What you are asking is directly related to the Fletcher Munson Bass curves https://en.m.wikipedia.org/wiki/Fletcher%E2%80%93Munson_curves

There are 2 distinct goals with sub placement.  You place subs for resolution and you place subs for room ambience. Room ambience exist under the Fletcher Munson curve and sweetpot resolution exists at a point over the curve. When you raise the
volume to read a flat signal you are basicaly raising the sub volume largely below the Munson curve. This lights ups the bass
 nodes in your room and starts infecting the resolution with boomy bass.
 
Subs working  for resolution are best raised (off the floor) and forward sitting in the sweetspot. Subs for room ambience are best placed on the floor behind the listener. This avoids the problems of multiple subs operating in a fashion that will raise bass boom.  I would be looking for flat bass response on the forward raised sub and not so much on a rear ambient sub.

Thank you!
I indeed am looking for resolution, thus with a forward raised sub as you state. Now where to find the sweet spot Rel says it is in the corner somewhat behind my main speakers, and thats where it is right now. Doing just fine, with settings I tested yesterday.


Cheers,
Marius

[Marius]

HI James,


Might seem a silly question, but could you specify the frequency response range of the 10bsub please?


I couldn't find it in the manual while I'm checking out some external balanced level controllers. They all seem to have a range of 20-20khz. Thus cutting off the sub-bass of the Subwoofer by at least a couple of hz's... So they're no use.

While i was at that, i found the manual of the 28b's. That also lists the 20-20khz range on page 4. As does the manual of the Bp26. Please tell me that is not to say they stop at 20hz

Cheers,
Marius

[James Tanner]

HI James,


Might seem a silly question, but could you specify the frequency response range of the 10bsub please?


I couldn't find it in the manual while I'm checking out some external balanced level controllers. They all seem to have a range of 20-20khz. Thus cutting off the sub-bass of the Subwoofer by at least a couple of hz's... So they're no use.

While i was at that, i found the manual of the 28b's. That also lists the 20-20khz range on page 4. As does the manual of the Bp26. Please tell me that is not to say they stop at 20hz

Cheers,
Marius

No they are wide bandwidth - generally 5Hz to 80,000Hz its just by law you quote distortion etc. at 20Hz to 20,000Hz

james

[Marius]

Thanks James,


Must say i never had any concerns, but testing one of these passive volume controls, i started wondering why at a certain frequency the sound cutoff suddenly and resolutely. If so, it must have been the level control, not the Bryston rig, which works its miracles as ever.


Cheers,
Marius

No they are wide bandwidth - generally 5Hz to 80,000Hz its just by law you quote distortion etc. at 20Hz to 20,000Hz

james