Does a high crossover setting conserve amp power?

[Cosmic Char]

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.

But I like my ears to bleed...!!!

 

[AcuDefTechGuy]

But I like my ears to bleed...!!!

In that case, no Crossover can help you.

 

[TheWarrior]

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.

Thats the general idea, yes. Regardless of crossovers used upstream of an amplifier, your program content varies constantly. Again, your amp's output is not frequency dependent.

Therefore, the only 'strain' you are preventing, is of inadequate speakers that are asked to perform beyond their capabilities. That's the whole point of using an LFE channel. But if you're running a truly full range speaker with a receiver, you probably just need more power!

 

[TheWarrior]

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?

For your application the only thing you should be concerned with is which crossover setting sounds the best to you! Sorry your question, turned in to a debate!

 

[PENG]

For your application the only thing you should be concerned with is which crossover setting sounds the best to you! Sorry your question, turned in to a debate!

I agree with you on this, but the answer to his question is a qualified yes, to what extent will largely depend on the crossover point and the contents of the music.

If the type of music spends a lot of time in frequencies well below the crossover point (not a brick wall), then the amp would deliver less power because the crossover network should effectively limit the current at frequencies well below the crossover set point. It won't make much difference whether the OP is referring to the AVR's, prepro crossover or the sub's, the answer remains basically the same.

Of course you are right about "No! Amp output is not frequency dependent!", but the impedance of the crossover network is. So in limiting the lower frequency current, a relatively higher crossover point such as 100-150 Hz as ADTG alluded to, will result in the power amp delivering less power, hence consuming less power. Again, it depends on how high the crossover is set to and the type of music. I really don't see much debate going on here as most have been in fact trying to answer his questions in different ways, except you seem to be insisting on a blanket "no" kind of answer.

 

[sterling shoote]

OP,

What do you perceive the benefit of power conservation to be? It's not like you're driving the amp too hard is it? Or, do you believe you'll get a cleaner sound, think again. Messing around with crossover for sub integration, is as futile as it is a never ending task from one music selection to another. I mostly relegate my sub to movies and use my full range mains for music. This eliminates the sensation of too much or too little bass. If there is low frequency I feel it. If there is no low frequency, I'm not manufacturing it.

 

[Lukester]

OP,

What do you perceive the benefit of power conservation to be? It's not like you're driving the amp too hard is it? Or, do you believe you'll get a cleaner sound, think again. Messing around with crossover for sub integration, is as futile as it is a never ending task from one music selection to another. I mostly relegate my sub to movies and use my full range mains for music. This eliminates the sensation of too much or too little bass. If there is low frequency I feel it. If there is no low frequency, I'm not manufacturing it.

I am using satellite speakers that require a high crossover so not using the subwoofer for music isn't an option for me. Fortunately, I'm using the sealed SVS SB-2000 sub which does an excellent job with a high crossover (even with music), so it hasn't been a problem. I guess the point of my question is for example, I know my Yamaha receiver has a "dynamic wattage" rating (meaning the receiver temporarily delivers extra power to the speakers when needed, similar to the dynamic wattage rating of a subwoofer) that kicks in when demanding movie sequences are driving all 5 speakers at high volume. If I have my crossover set at 120hz (which works best with my speakers), wouldn't sending the majority of the bass/LFE to my subwoofer be easier on the receiver than driving full sized speakers with the same material/volume at 80 or 60hz crossover?

 

[markw]

Keep in mind that small speakers will only play so loud cleanly. While they might be able to "survive" power, odds are they won't do it without complaining.

Also, keep in mind consider that doubling the power to your speakers will result in a 3 increase in sound level, which is barely audible.

The weak link in your system is your speakers, not your amp.

IOW, your power issue is a moot point.

 

[D Bone]

I am using satellite speakers that require a high crossover so not using the subwoofer for music isn't an option for me. Fortunately, I'm using the sealed SVS SB-2000 sub which does an excellent job with a high crossover (even with music), so it hasn't been a problem. I guess the point of my question is for example, I know my Yamaha receiver has a "dynamic wattage" rating (meaning the receiver temporarily delivers extra power to the speakers when needed, similar to the dynamic wattage rating of a subwoofer) that kicks in when demanding movie sequences are driving all 5 speakers at high volume. If I have my crossover set at 120hz (which works best with my speakers), wouldn't sending the majority of the bass/LFE to my subwoofer be easier on the receiver than driving full sized speakers with the same material/volume at 80 or 60hz crossover?

It seems getting an answer to your question is harder than it should be! The simple answer is simply - YES.

 

[Lukester]

Keep in mind that small speakers will only play so loud cleanly. While they might be able to "survive" power, odds are they won't do it without complaining.

Also, keep in mind consider that doubling the power to your speakers will result in a 3 increase in sound level, which is barely audible.

The weak link in your system is your speakers, not your amp.

IOW, your power issue is a moot point.

Wow, apparently this forum seems incapable of answering a question without including a personal opinion. My question has nothing to do with my speakers maximum output capabilities. Which by the way, your blanket statement about small speakers is very debatable. In many cases, a well designed satellite speakers maximum output/distortion level is comparable to bookshelf or tower speaker. The difference is in the frequency response (which is why having the right sub paired with small speakers is so important). I currently use a modestly rated Yamaha receiver. It might be beneficial to upgrade to a better receiver in the future. I'm trying to determine how beneficial that might be. If I'm saving some strain on my amp with a high crossover, that is something to consider (I do watch a decent amount of blu-ray movies at high/reference level).

 

[markw]

Fine, you go on believing what you want. You seem to know more than we do.

But, you can't argue with the laws of physics.

 

[Swerd]

Lukester

Your original question "Does a high crossover setting conserve amp power?" had people scratching their heads because the answers are rather meaningless. The weak link in all systems I've heard is nearly always the speakers, not the amp.

I took a moment to look up what you now have. That Yamaha AVR, at 80 wpc (when 2 channels are measured at FTC conditions), has plenty of power to drive your Klipsch Quintet speakers. Klipsch claims these speakers have an unbelievably high sensitivity of 91 dB. (As a guess, 84 dB or less is more likely.) But if their claim is true, then your Yamaha AVR could easily drive those speakers to levels much louder than you would like in your home.

My question has nothing to do with my speakers maximum output capabilities.

I currently use a modestly rated Yamaha receiver. It might be beneficial to upgrade to a better receiver in the future. I'm trying to determine how beneficial that might be. If I'm saving some strain on my amp with a high crossover, that is something to consider.

So, despite your denial, the answer to your question really does have everything to do with your speakers maximum output capabilities. The Yamaha amp is not being strained driving those speakers, with or without the subwoofer.

Doubling the power to an AVR with 160 wpc will cost you plenty and may provide, at best, barely noticeable audible benefits. Those rather small speakers (it's a simple fact – don't be sensitive about the word small) can only deliver so much before they hit their limit. Whether they complain when they hit that limit, or whether they simply fail to get louder, doesn't matter. All speakers have an upper limit. Speaking generally, small speakers have lower upper limits than larger speakers.

A far more effective approach would be to keep the AVR and think about different speakers. Like markw suggested.

The weak link in your system is your speakers, not your amp.

IOW, your power issue is a moot point.

 

[Lukester]

Lukester

Your original question "Does a high crossover setting conserve amp power?" had people scratching their heads because the answers are rather meaningless. The weak link in all systems I've heard is nearly always the speakers, not the amp.

I took a moment to look up what you now have. That Yamaha AVR, at 80 wpc (when 2 channels are measured at FTC conditions), has plenty of power to drive your Klipsch Quintet speakers. Klipsch claims these speakers have an unbelievably high sensitivity of 91 dB. (As a guess, 84 dB or less is more likely.) But if their claim is true, then your Yamaha AVR could easily drive those speakers to levels much louder than you would like in your home.
So, despite your denial, the answer to your question really does have everything to do with your speakers maximum output capabilities. The Yamaha amp is not being strained driving those speakers, with or without the subwoofer.

Doubling the power to an AVR with 160 wpc will cost you plenty and may provide, at best, barely noticeable audible benefits. Those rather small speakers (it's a simple fact – don't be sensitive about the word small) can only deliver so much before they hit their limit. Whether they complain when they hit that limit, or whether they simply fail to get louder, doesn't matter. All speakers have an upper limit. Speaking generally, small speakers have lower upper limits than larger speakers.

A far more effective approach would be to keep the AVR and think about different speakers. Like markw suggested.

Thank you for this comprehensive answer. I guess I should have explained myself better. My speakers have plenty of volume and clarity for my living room (under 2000 sq. ft.). The reason I was asking this question about a possible receiver upgrade is because while driving a couple of intense action sequences via blu-ray movies at loud volume, my sound system cut out for a second (even saw the blip on the receivers screen). My receiver has only done this about two or three times. My initial reaction was that the receiver had clipped or overheated. As you mentioned, my Klipsch are rated at 91db sensitivity (Klipsch even claims the center is rated at 94db!), so it sounds like my receiver may be experiencing a different issue. Not sure what it is, but according to your response, it doesn't sound like a lack of power. I apologize if I sounded rude, I did not understand what markw was getting at.

 

[Swerd]

I'm glad my answer made sense .

The reason I was asking this question about a possible receiver upgrade is because while driving a couple of intense action sequences via blu-ray movies at loud volume, my sound system cut out for a second (even saw the blip on the receivers screen). My receiver has only done this about two or three times.

I'm only guessing, but I think this suggests that your Klipsch speakers have reached their limit. Apparently they are built well enough to briefly survive power levels that high without failing. You should consider yourself lucky that your Yamaha has good overload protection circuits. They saved your speakers. Other (unnamed) AVRs have been known to blow out speakers when they overload.

Now that you explained the background, I am more certain that your speakers are the limiting factor, not your receiver. Without measuring your speakers, I would guess they have a sensitivity no greater than 83-84 dB. When you turned up the volume, they reached their limit.

Remember that speaker sensitivity is measured as how loud they sound to a test microphone 1 meter away, when they are given 1 watt (or more correctly 2.83 volts). You probably sit further away than 1 meter, more like 8-10 feet away from the speakers, so that 1 watt signal will be quieter. If you have a SPL meter, you'd be surprised how loud 91 dB is.

My comments about speaker sensitivity are general, not specific to yours. Most small bookshelf sized speakers (2-ways with a 5½" or 6½" woofer) have a sensitivity of about 83-85 dB. MTM speakers, with 2 similarly sized woofers, are about 87-89 dB. Large ruggedly built PA speakers, used in large auditoriums, can be as sensitive as 91-93 dB. Many commercial speaker makers exaggerate their sensitivity numbers because they know most buyers believe louder is better. Klipsch does build some good speakers, but they are also one of the well known exaggerators of sensitivity.

 

[highfigh]

Thank you for this comprehensive answer. I guess I should have explained myself better. My speakers have plenty of volume and clarity for my living room (under 2000 sq. ft.). The reason I was asking this question about a possible receiver upgrade is because while driving a couple of intense action sequences via blu-ray movies at loud volume, my sound system cut out for a second (even saw the blip on the receivers screen). My receiver has only done this about two or three times. My initial reaction was that the receiver had clipped or overheated. As you mentioned, my Klipsch are rated at 91db sensitivity (Klipsch even claims the center is rated at 94db!), so it sounds like my receiver may be experiencing a different issue. Not sure what it is, but according to your response, it doesn't sound like a lack of power. I apologize if I sounded rude, I did not understand what markw was getting at.

2000 square feet, or 2000 cubic feet?

If your AVR cut out, did you see any lights flicker at the same time? Might have been a drop in line voltage that caused this- are you far from a transformer?

Inspect the ends of the speaker wires and make sure no stray strands are sticking out where they may touch something they shouldn't. It would be a good idea to monitor your line voltage, as well. There's a thing called Kill A Watt, which is used for monitoring power consumption and they're not terribly expensive- if you see the voltage drop, it would be time to check it out. I would also check the power cord- they can work their way out of the IEC socket on the back.

If your room is actually 2000 square feet, small speakers will have a hard time making the sound "real" because there's not as much cone surface area. There are a few things that allow high SPL and they all involve the volume of air that moves as a result of the cone's motion. If you have 5" drivers in the satellites, they may be loud, but not at low frequencies and when it comes to speakers and what is fed to them, it's a lot like that saying "Never teach a pig to sing- it sounds bad and annoys the pig". You may be able to have good bass from small speakers, but not in a large room- a small diaphragm won't create much pressure.

To address your original question- if your main amplifier is sending low frequencies to your satellites and they have small drivers with low excursion, it's hard for the speakers to produce much bass, so there's really no good reason to send those frequencies to the speakers and, since power is involved in the signal you're sending, your amplifier will be able to cruise along without being strained. Amplifier power ratings are often specified at 1KHz, for a reason- they output more at 1KHz than at 20Hz and since marketing departments have free reign over the advertising, the larger number is shown. Unless the amplifier is designed with an extremely stout power supply, it will not produce as much power when the frequency bandwidth extends from 20-20KHz as it would if it was limited to 150Hz-20KHz. If you get the Kill A Watt, you will see this in the display. However, the effect of limiting the frequency range probably won't be very noticeable at low or moderate power levels.

Also, your speakers are rated for 91dB/W, but at what frequency? The only time that spec is valid is when they provide a frequency response range with +/- xdB and then, the smaller total deviation is definitely preferred. If a speaker is rated with +/-3dB, the 6dB difference means you would have to quadruple the power at the frequency with lower sensitivity to measure the same SPL as the higher sensitivity frequency and that's substantial. The Klipsch RP-150M is rated for 45-25KHz +/-3dB and if the range from 45-80Hz is 3dB below the median level and everything above 80Hz is in the +3dB range, it will definitely be lacking in the bass department. If the -3dB range is 8KHz-25KHz, it will seem to have good bass but the mids may seem a bit strong. If the lower end of that -3dB range slides down to 400Hz and everything below is in the +3dB range, it may sound "pretty impressive, for a small speaker". Many speakers are designed to compromise- they know bass won't be strong unless they remove some of the midrange and use a less sensitive tweeter. If 80Hz is +3dB and 45Hz is -3dB, they won't provide much thump.

 

[Lukester]

I'm glad my answer made sense .
I'm only guessing, but I think this suggests that your Klipsch speakers have reached their limit. Apparently they are built well enough to briefly survive power levels that high without failing. You should consider yourself lucky that your Yamaha has good overload protection circuits. They saved your speakers. Other (unnamed) AVRs have been known to blow out speakers when they overload.

Now that you explained the background, I am more certain that your speakers are the limiting factor, not your receiver. Without measuring your speakers, I would guess they have a sensitivity no greater than 83-84 dB. When you turned up the volume, they reached their limit.

Remember that speaker sensitivity is measured as how loud they sound to a test microphone 1 meter away, when they are given 1 watt (or more correctly 2.83 volts). You probably sit further away than 1 meter, more like 8-10 feet away from the speakers, so that 1 watt signal will be quieter. If you have a SPL meter, you'd be surprised how loud 91 dB is.

My comments about speaker sensitivity are general, not specific to yours. Most small bookshelf sized speakers (2-ways with a 5½" or 6½" woofer) have a sensitivity of about 83-85 dB. MTM speakers, with 2 similarly sized woofers, are about 87-89 dB. Large ruggedly built PA speakers, used in large auditoriums, can be as sensitive as 91-93 dB. Many commercial speaker makers exaggerate their sensitivity numbers because they know most buyers believe louder is better. Klipsch does build some good speakers, but they are also one of the well known exaggerators of sensitivity.

Thanks for the info. FYI, I meant to say 2000 cubic feet (not square feet) on my room size. I do have a C weighted SPL meter on my phone (not sure how accurate it is), but when I was playing the intense action sequence that caused my receiver to cut out for a second, my SPL meter was seeing 90-93db spikes from my sitting position. If my speakers had reached their limit, wouldn't they, in theory, be cutting out when I blast my music (I had my receiver master volume set at -10db on occasion just to see what my sound system could handle)? Because I've only witnessed my receiver drop the sound for a second during intense action scenes from two or three movies I own and when I played the scenes again the system did not always repeat the issue.

 

[PENG]

Thanks for the info. FYI, I meant to say 2000 cubic feet (not square feet) on my room size. I do have a C weighted SPL meter on my phone (not sure how accurate it is), but when I was playing the intense action sequence that caused my receiver to cut out for a second, my SPL meter was seeing 90-93db spikes from my sitting position. If my speakers had reached their limit, wouldn't they, in theory, be cutting out when I blast my music (I had my receiver master volume set at -10db on occasion just to see what my sound system could handle)? Because I've only witnessed my receiver drop the sound for a second during intense action scenes from two or three movies I own and when I played the scenes again the system did not always repeat the issue.

In a 2000 cu ft room a good mid range AVR should have enough power to drive your Klipsch satellites to produce 93 dB peak based on the info provided on those speakers. If you set the crossover frequency to 120 Hz, the answer to your question is "yes" but what we are trying to tell you is that the gain is not significant. As Mark cited, doubling the power output will get you only 3 dB more. By setting the crossover to 120 Hz, you AVR may gain a fraction of a dB of headroom so that is not significant at all. If we all just give you a yes/no answer we may mislead you to think that you have the problem (if you do have a problem) solved just by setting the crossover higher but it is not that simple. I hope you understand we are only trying to help.

 

[Swerd]

Thanks for the info. FYI, I meant to say 2000 cubic feet (not square feet) on my room size. I do have a C weighted SPL meter on my phone (not sure how accurate it is), but when I was playing the intense action sequence that caused my receiver to cut out for a second, my SPL meter was seeing 90-93db spikes from my sitting position. If my speakers had reached their limit, wouldn't they, in theory, be cutting out when I blast my music (I had my receiver master volume set at -10db on occasion just to see what my sound system could handle)? Because I've only witnessed my receiver drop the sound for a second during intense action scenes from two or three movies I own and when I played the scenes again the system did not always repeat the issue.

If your speakers reach their limit, a number of things might happen. The voice coils could heat up enough to melt the glue between the coil and the cone or the support spider. Or worse, the voice coils could melt and fuse. Both of these would result in permanent speaker failure, not a temporary cut out. Your Yamaha AVR sensed that something was wrong (increasing heat causes impedance to rapidly change, rise if I remember correctly) and cut things off quickly before it got worse. It was warning you that you were driving the speakers too hard.

These are the Klipsch Quintet speakers in question. They are small satellite speakers, but they may be more potent than most other small satellites. They are 4" wide × 7½" high × 5½" deep. They have a 3½" woofer and a ¾" aluminum compression (?) tweeter mounted behind a horn. The satellites weigh 6¼ lbs. each, and Klipsch recommends amp power from 75-300 watts (EEK)!!!

http://www.soundandvision.com/content/klipsch-quintet-speaker-system-ht-labs-measures#IxjHYmt3SyhtTsDy.97

Sound & Vision says they estimate sensitivity at 87.5 dB (range 500 to 2000 Hz) for the satellite speakers and 90 dB for the center. That's less than the 91 and 94 dB that Klipsch claims, but 87.5 dB for a small 3½" woofer satellite speaker is still rather loud.

Remember, sensitivity ratings tell you how loud they get when given 1 watt. Think of that as a measure of how little power you need to drive them. Sensitivity says nothing about a speaker's upper power handling limit.

 

[Lukester]

If your speakers reach their limit, a number of things might happen. The voice coils could heat up enough to melt the glue between the coil and the cone or the support spider. Or worse, the voice coils could melt and fuse. Both of these would result in permanent speaker failure, not a temporary cut out. Your Yamaha AVR sensed that something was wrong (increasing heat causes impedance to rapidly change, rise if I remember correctly) and cut things off quickly before it got worse. It was warning you that you were driving the speakers too hard.

These are the Klipsch Quintet speakers in question. They are small satellite speakers, but they may be more potent than most other small satellites. They are 4" wide × 7½" high × 5½" deep. They have a 3½" woofer and a ¾" aluminum compression (?) tweeter mounted behind a horn. The satellites weigh 6¼ lbs. each, and Klipsch recommends amp power from 75-300 watts (EEK)!!!

http://www.soundandvision.com/content/klipsch-quintet-speaker-system-ht-labs-measures#IxjHYmt3SyhtTsDy.97

Sound & Vision says they estimate sensitivity at 87.5 dB (range 500 to 2000 Hz) for the satellite speakers and 90 dB for the center. That's less than the 91 and 94 dB that Klipsch claims, but 87.5 dB for a small 3½" woofer satellite speaker is still rather loud.

Remember, sensitivity ratings tell you how loud they get when given 1 watt. Think of that as a measure of how little power you need to drive them. Sensitivity says nothing about a speaker's upper power handling limit.

Ok, I think I have my answers at this point. Obviously my receiver being underpowered isn't the issue. When I original set up this system I had the receiver crossover set at 110hz (I encountered my receiver cut out issue at that time). I recently increased my crossover to 120hz, but haven't tested again to see if the issue is still present. It could be that the receiver did sense the speakers were being pushed too hard (110hz is the speaker's lower limit after all). I do find it odd that other times I pushed the speakers into the 90db+ volume range that they didn't have any problems. Well, I guess at this point I will do some more testing to see what happens. And if it is either the speakers limits or the receiver having some other issue (like HDMI handshake or speaker connection), I will go from there. Thanks again for your help and sorry for all of the questions/confusion.