8040A and accurate input level - Forum

1/ What is the maxium level that can be put into 8040A and, in the same way, what are the recommanded levels (a range) to be used with 8040A ?

Hi,

The maximum input level can be limited either by the electrical components in the input stage or the acoustical maximum output of the speaker, in a properly designed speaker it's always the latter one. So for the 8040A the maximum usable input level is around -1 dBu (with max -6 dBu sensitivity setting) to +11 dBu (with min +6 dBu sensitivity setting). There is no recommended setting because it all depends on the output level of your source.

Since your Sonos can output around +8 dBu, I would turn the sensitivity to the maximum -6 dBu (yes, -6 dBu) so that you will ensure that the speaker is able to output its maximum SPL if requested.

2/ What is the purpose of the input sensivity button at the rear of 8040A : from -6dBu to +6dBu ? Do I have to turn it to have better results with my Sonos ?

Please read this first. If you have still have further questions, I'd be happy to help.

http://www.genelec.com/faq/applicable-t ... nsitivity/

Ok I think I understand.

If I chose a sensitivity of -6dBu, the 8040A will need -1dBu to get the maximum SPL level.

Mathematically, using a source that can output +8dBu (Sonos), a sensitivity of +3dBu gives the maximum SPL level:

Input sensitivity is +3 dBu = 100 dB SPL@1m
Max rms output SPL stated on the datasheet 105 dB SPL@1m
Additional rms input level required for maximum rms output +5 dB
Max rms input level required for maximum rms output +3 dBu + 5 dB = +8 dBu = Sonos maximum output level

So, using a sensitivity of -6dBu will always give the maximum SPL, because you only need -1dBu!

So this sensitivity is useful when you want to temper the maxium acoustic level (depending of you source of course, that's why you can adjust this level on serious hardware such as Benchmark DAC1 using calibration trimmers).


Is it correct ?

Thank you for all

Cédric

Ok I think I understand.

If I chose a sensitivity of -6dBu, the 8040A will need -1dBu to get the maximum SPL level.

Mathematically, using a source that can output +8dBu (Sonos), a sensitivity of +3dBu gives the maximum SPL level:

Input sensitivity is +3 dBu = 100 dB SPL@1m
Max rms output SPL stated on the datasheet 105 dB SPL@1m
Additional rms input level required for maximum rms output +5 dB
Max rms input level required for maximum rms output +3 dBu + 5 dB = +8 dBu = Sonos maximum output level

That is correct.

So, using a sensitivity of -6dBu will always give the maximum SPL, because you only need -1dBu!

Not always, only when the output level of the source device is -1 dBu or above. Meaning near the maximum volume settings of the Sonos (9 dBu below maximum volume/output level). Usually the whole range of volume control is something around 70 - 90 dB.

So this sensitivity is useful when you want to temper the maxium acoustic level (depending of you source of course, that's why you can adjust this level on serious hardware such as Benchmark DAC1 using calibration trimmers).

Is it correct ?

No. The sensitivity setting is meant for adjusting the speaker's input sensitivity so that the speaker can achieve maximum output before the source device hits its maximum output level. So if you have a source that can't output high output levels, you need more gain/sensitivity on the speaker and vice versa. Clear as mud?

Thank you Ikka!

It is very interesting!

Cédric

LEt me ask you something else? The thing is, i have to keep the output level of my RME pretty low to keep it in a decent listening volume. I'm using +4dbu on the card's output and -6 set on my 8040s, but isn't that the "loudest" combination I can get? (if you get what i mean?) What I'm saying the signal seems to be pretty hot and genies are just way too loud to work with in a normal volume setting (maybe 50%?).

I'm not sure if I'm just being stupid which is quite likely, but still would be happy if you could spare another couple of minutes and clear this up for me!

Cheers

Hi,

Yes, +4 dBu output and -6 dBu input sensitivity is the loudest setting. I would recommend turning down the input sensitivity, even down to +6 dB if needed.