Does a high crossover setting conserve amp power?

[Lukester]

I have a question regarding receiver/amp power. Does a high crossover setting conserve amp power? Example: I use satellite speakers that require a higher crossover setting with the subwoofer than your average speaker. Does the higher I set the receiver's crossover setting translate into lower power consumption for the speakers or does the crossover have no relevance to a speakers power consumption?

 

[lovinthehd]

Yes, limiting the lower frequencies to the speaker would be a lesser load on the amp.

PS at this point was assuming OP had proper bass management in his avr/amp....not an old school 2ch setup.

 

[markw]

The downside of this is that it by having more mid/upper bass coming from the sub it can make it easier to localize the sub and might make the system sound "bloated".

 

[lovinthehd]

The downside of this is that it by having more mid/upper bass coming from the sub it can make it easier to localize the sub and might make the system sound "bloated".

True and ideally you chose a sub and sat together so they complement each other's frequency range but depending where your sub needs to be located for best results that may not alleviate localization. Multiple subs can reduce localization, too. I run my crossover at 120 as my subs are quite capable of higher frequency response, and I don't have localization issues.

 

[TheWarrior]

No! Amp output is not frequency dependent!

We've had this question a lot lately...

 

[j_garcia]

The side effect is that sound begins to be localized at around 120Hz, so when that sound starts coming from the sub you will begin to be able to tell where it is in the room. Splitting off output in a higher range for the sub means some sounds that would not be normally going to it in that localizable range will be more noticeably split between the speaker and sub. Speaker quality will be a big factor here, because a speaker that can't extend to around 50-60Hz convincingly already will already be an issue, so the sub will need to be good enough to handle the range.

 

[lovinthehd]

No! Amp output is not frequency dependent!

We've had this question a lot lately...

How does that work? If you high pass the frequencies the amp sees the amp isn't producing the lower frequencies, or are you saying the attenuation is post-amp?

 

[j_garcia]

No! Amp output is not frequency dependent!

We've had this question a lot lately...

In the case of a receiver, you are limiting the signal that is being sent to the amp section, so it should be drawing less current because it is no longer amplifying as much sound. Are you saying that's not the case?

 

[lovinthehd]

Yes, if you're using a power amp without any crossover before it, and are sending full signal out to your speakers thru a sub with its own high pass filter, the power amp is seeing full band. Not an issue for a modern unit with bass management..

 

[Lukester]

Thanks for the input. I am using a Yamaha RX-V477 receiver with the Klipsch Quintet V and the SVS SB-2000. The SB-2000 does an excellent job with upper base frequencies especially considering that my receiver has no subEQ. I have the SB-2000 sitting on the left hand side of my TV stand, so it is near the center (sits on the TV stand) and front speakers (wall mounted).

 

[j_garcia]

I think the SB-2000 will be fine like that.

 

[PENG]

Yes, if you're using a power amp without any crossover before it, and are sending full signal out to your speakers thru a sub with its own high pass filter, the power amp is seeing full band. Not an issue for a modern unit with bass management..

Not really true, the sub's high pass network will offer high impedance to the lower bands thereby limiting current draw from the power amp, and that means the power amp will still delivering less power relatively speaking. How much less will depend on the crossover point, characteristics of the crossover, and obviously the music contents.

 

[TheWarrior]

When you're talking about an electronic crossover in the preamp, you are still sending a signal which is amplified. A solid state amp doesn't care what frequency that is! Tube, yes!

 

[lovinthehd]

Not really true, the sub's high pass network will offer high impedance to the lower bands thereby limiting current draw from the power amp, and that means the power amp will still delivering less power relatively speaking. How much less will depend on the crossover point, characteristics of the crossover, and obviously the music contents.

Yeah, sorry, still thinking more line level than high level using a sub's high pass filter, d'oh!....but I wouldn't even bother using a sub with high level inputs myself unless there wasn't any other solution available. For the OPs purposes now that he confirms his eqpt, he will use less avr amp with bass management.

 

[lovinthehd]

When you're talking about an electronic crossover in the preamp, you are still sending a signal which is amplified. A solid state amp doesn't care what frequency that is! Tube, yes!

?

 

[lovinthehd]

When you're talking about an electronic crossover in the preamp, you are still sending a signal which is amplified. A solid state amp doesn't care what frequency that is! Tube, yes!

If you have an electronic xover in the preamp then the amp doesn't see the low frequencies you filter and would be more efficient not having to reproduce what is the hardest on an amp, the lower frequencies.....

 

[PENG]

When you're talking about an electronic crossover in the preamp, you are still sending a signal which is amplified. A solid state amp doesn't care what frequency that is! Tube, yes!

An AVR's preamp section generally uses less power than it's power amp section for normal use at most listening level because it's output current is very low. Power = Voltage X current X power factor X distortion factor (most would ignore DF). Yes, the amp may amplify the signal regardless of the frequency in terms of voltage but the current is limited by a crossover, the power delivered will be reduced. As an extreme example to make it clear, you can have the power amp output sitting at 30V but you don't have a load (speaker) connected to it, there is no power delivered by the power amp because Power = 30X0=0.

 

[Steve81]

A couple thoughts...By setting a high pass filter on your AVR, obviously the potential exists to greatly reduce the demands on the AVR's built in amplifiers. That said, there are no guarantees as to how much demand is reduced. Peaks can occur at any given time well above the typical subwoofer XO range, so you can't necessarily skimp on power just because you're using a sub.

The big benefit is to the speakers themselves, as reproducing 100dB at 60Hz requires one to move 4x more air than 100dB at 120Hz.

 

[Cosmic Char]

This thread seems like more of an academic discourse, rather than a practical discussion. If you need more "power", add an external amp. Plain and simple.

 

[AcuDefTechGuy]

This thread seems like more of an academic discourse, rather than a practical discussion. If you need more "power", add an external amp. Plain and simple.

There are people who may need an external amp (Outdoor or Stadium-size venues). In this case, it is not very practical.

But I think if most people set the XO @ 100-150Hz, assuming their Subs are capable and the resulting sound is good, they may NOT need an external amp. In this case, it is very practical.