Hissing from Genelec G Two at short range — should I be worried?

[bungle]

It is a bit shame that only 4 out of 10 Genelec monitors on that list are our current production models, all others are old and discontinued. Obviously, as technology evolves, self noise levels are coming down with every new model/platform. Our most recent 8380A is the "quietest" monitor we have ever produced, measuring under 0 dBA at 1 meter distance. Previous record holder holder was the 8331A.

With analog models you can usually get hiss down by adjusting sensitivity, e.g. 8050A , and smaller I used that. With S360A the noise seems to be always the same, no matter what sensitivity you use. Why is that?

 

[Ilkka Rissanen]

With analog models you can usually get hiss down by adjusting sensitivity, e.g. 8050A , and smaller I used that. With S360A the noise seems to be always the same, no matter what sensitivity you use. Why is that?

Analogue and SAM monitor's block diagram and signal chain is completely different. Input sensitivity adjustment is located little different there. How are you adjusting the S360? From the GLM software or from the physical gain trimmer at the back of the loudspeaker? Are you using analogue or digital input? Note that the GLM adjustment always overrides the physical gain trimmer if the GLM network in connected.

 

[Mort]

Passive speakers/systems have hiss too, it is just at lower level and in many times not as audible. The difference comes from the fundamental difference in signal chain.

Active speaker: crossover filtering -> power amplier(s) -> drivers
Passive speaker: power amplier(s) -> crossover filtering -> drivers

In active speakers the power ampliers are directly connected to the drivers, there is nothing in between (in some cases there might be a single high pass capacitor on the tweeter output channel) attenuating the low level noise coming from the power ampliers. The amplifiers are seeing the raw response of the drivers without any attenuation which results in much higher acoustical sensitivity compared to a passive system which has been filtered in between the power amplifiers and the drivers. In many cases the difference can be up to 5 - 15 dB SPL / W depending on the raw response of the drivers and possible waveguides which boost the sensitivity even further. In passive speakers the crossover filtering acts up as a brake in between the power amplifiers and drivers, attenuating the low level noise considerably. The same filtering will also cause unlinearity and losses which are absent in an active speaker design.

What then is the benefit to the active signal chain order? I assume there is some benefit to having the crossover filtering first and the amp second?

 

[Ilkka Rissanen]

What then is the benefit to the active signal chain order? I assume there is some benefit to having the crossover filtering first and the amp second?

1. Perfectly Matched Amplifier–Driver Interaction​

In an active speaker, the amplifier channels are designed specifically for each driver (LF, MF, HF):

• Optimized voltage/current capability for driver impedance and thermal limits.
• Predictable damping factors because there’s no passive crossover between the amp and the driver.
• Improved control of cone motion, especially in bass drivers where passive crossovers contribute resistance and reduce electrical damping.

Result: higher headroom, lower distortion, and better transient response.

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2. DSP-Based Crossovers With Far Superior Precision​

Active systems can use digital crossovers rather than passive LC networks:

• Exact crossover slopes and alignments (FIR, IIR, linear-phase, hybrid).
• No insertion loss, unlike passive components that waste power as heat.
• Time alignment between drivers via delay compensation.
• Driver EQ (correcting for resonance, breakup modes, horn EQ, baffle step, etc.).

Result: smoother on-axis and off-axis response, better phase coherence, and more consistent performance.

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3. Reduced Nonlinearities​

Passive components (inductors, capacitors) introduce:

• Saturation
• ESR-related losses
• Power compression
• Component drift with temperature

Active systems bypass all of this by placing the crossover before amplification.

Result: significantly lower distortion and power compression at high SPL.

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4. Integrated System Protection​

Active designs can include intelligent protection schemes that are impossible in passive designs:

• Thermal modelling of drivers
• Excursion limiting
• RMS/peak limiting per band
• Soft clipping and lookahead limiters

Because the amplifier “knows” the driver’s limits, protection can be precise instead of overly conservative.

Result: higher usable SPL and dramatically lower failure rates.

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5. Better Gain Structure and Noise Performance​

In a typical passive system:

• The amplifier is external.
• Line-level signal may travel long distances.
• Gain structure varies depending on user setup.

In an active speaker:

• Internal gain structure is fixed and optimized.
• Amplifier input stages are matched to DSP output stages.
• Noise performance is consistent and predictable.

Result: lower noise floor and more repeatable system performance.

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6. Cable Losses Are Greatly Reduced or Eliminated​

Passive systems require high-current speaker cables:

• Voltage drop increases with cable length.
• High damping factor is compromised.
• Expensive thick-gauge cables are needed for long runs.

Active systems use:

• Short internal speaker cables (centimeters long).
• Long signal-level cables, which are immune to the issues above.

Result: better efficiency and more consistent response over distance.

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7. System Consistency and Repeatability​

Passive systems rely heavily on external amplifiers, processors, and user configuration, leading to variability.

Active systems are turnkey:

• The designer controls every variable.
• Performance is consistent across units and installations.
• No risk of mismatched amps, incorrect crossover settings, or wrong limiters.

Result: predictable performance—critical in pro audio, broadcast, studio, and installed systems.

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8. Lower Total System Cost at Equivalent Performance​

While an active speaker unit may cost more, the entire system removes the need for:

• External amplifiers
• Passive crossovers
• System processors
• Heavy-gauge cabling
• Rack space and cooling

When you sum up the entire signal chain, high-performance active systems often have a lower total cost of ownership.

 

[bungle]

Analogue and SAM monitor's block diagram and signal chain is completely different. Input sensitivity adjustment is located little different there. How are you adjusting the S360? From the GLM software or from the physical gain trimmer at the back of the loudspeaker? Are you using analogue or digital input? Note that the GLM adjustment always overrides the physical gain trimmer if the GLM network in connected.

Right now I am using analog input and adjusting sensitivity with GLM (and storing the settings to speakers). I think I tried two extremes with sensitivity, but as it didn’t have any effect on hiss, I just leaved sensitivity at max. Not that it really matters with real signal and listening position.