Matching amp(s) to speakers; speaker continuous power capability unknown

[CMcD-USC]

I have an older pair of speakers that has a nominal impedance of 6 ohms and sensitivity of 91dB. Their spec sheet, rather than specifying continuous power output capability, merely states that the speakers are "suitable for use with amplifiers rated from 20Wpc to 100Wpc" (these were previously driven in a passive bi-amp configuration by a pair of NAD 30W X 2 amplifiers that were bridgeable to 90 watts). I had dug up the spec sheet on the speakers after reading articles articulating the general principle that it's a decent rule of thumb to pair speakers with an amplifier that has ~1.5-2X the speakers' continuous power rating.

Lacking a published continuous power rating for the speakers, should the spec sheet be taken at face value such that I should be looking at replacement amplifier(s) that don't significantly exceed 100Wpc (if at all)? If I do have some wiggle room in what I choose, where should I reasonably set the output ceiling for the amplifiers I'm looking at so that I am maximizing the speakers' capabilities but maintaining some sweep and precision in the volume control?

 

[PENG]

I have an older pair of speakers that has a nominal impedance of 6 ohms and sensitivity of 91dB. Their spec sheet, rather than specifying continuous power output capability, merely states that the speakers are "suitable for use with amplifiers rated from 20Wpc to 100Wpc" (these were previously driven in a passive bi-amp configuration by a pair of NAD 30W X 2 amplifiers that were bridgeable to 90 watts). I had dug up the spec sheet on the speakers after reading articles articulating the general principle that it's a decent rule of thumb to pair speakers with an amplifier that has ~1.5-2X the speakers' continuous power rating.

Lacking a published continuous power rating for the speakers, should the spec sheet be taken at face value such that I should be looking at replacement amplifier(s) that don't significantly exceed 100Wpc (if at all)? If I do have some wiggle room in what I choose, where should I reasonably set the output ceiling for the amplifiers I'm looking at so that I am maximizing the speakers' capabilities but maintaining some sweep and precision in the volume control?

Do they provide the "continuous" rating, can you post the spec sheet?

 

[lovinthehd]

What speakers are they? You could always use a much more powerful amp than even 2x as long as you use some sense with the volume control, too.

 

[CMcD-USC]

What speakers are they? You could always use a much more powerful amp than even 2x as long as you use some sense with the volume control, too.

Speakers are Snell Acoustics Type E/iii. The brief specs that I put in the original post were cut and pasted from Stereophile, but looking at the exact spec sheet in my file, they are a little different from what Stereophile reflected. Here they are directly from the original 1993 spec sheet:

Typical listening room amplitude response on-axis or up to 25 degrees off the horizontal axis:
+/- 1.75 dB from 39 Hz to 20 kHz anechoic

Crossover frequencies: 2.7 kHz (Stereophile additionally references 24 dB/octave slope)

Nominal Impedance: 6 ohms

Sensitivity: 91 dB w/1 watt at 1 meter (anechoic)

Driver complement:
8" high power handling woofer
1" treated textile dome tweeter
.75 soft dome rear-firing tweeter

Power Requirements:
Suitable for use with amplifiers 15 to 150 watts (note that this was key difference in what was listed on Stereophile, which reference 20-100 Wpc)

I actually have two pairs of the Type E/iii speakers and a Snell CC-1 center that I intend to cobble into a 5.1 surround system. At minimum and assuming I use an AVR, I will run a pre-out and separately amplify the front channel speakers with a good stereo amplifier or amplifiers for listening to music (I have a sentimental attachment... purchased the first set of E/iiis in 1993 as a college graduation present to myself and my in-laws bought a matching pair around the same time on my recommendation and ended up giving them to me recently when they downsized).

 

[lovinthehd]

I always prefer to look at a manual if possible, or at least the manufacturer's spec sheet over that of a retailer/reviewer.....altho the measurements in a review can be interesting for details. Keep in mind a max continuous rating is more about when you might incur damage, and the minimum is pretty much useless; a speaker driven to a max continuous rating I think is often simply unlistenable, partly just for being too loud but other issues that may come along such as compression and distortion. Never got a chance to hear a Snell, but they generally are well regarded.

Measurements from that review: https://www.stereophile.com/content/snell-type-eiii-loudspeaker-measurements

 

[CMcD-USC]

The specs from my second post were directly from Snell's spec sheet, so those are probably the "official" ones (their instruction manual was generic to care, wiring configs, etc. and contained no specs; I had cut and pasted the "suitable for..." amp language from Stereophile as I made the original post before making it home to look at the spec sheet).

I did note that the Stereophile review used two test amps, one of which output 250 Wpc/8 ohms or 500 Wpc at 4 ohms; I guess as much as anything, I don't want to inadvertently goose the volume of whatever setup I put together and cook the speakers.

I was always pleased with the speakers' sound quality even though they were at the more economical end of Snell's line before the company went belly up years ago. When I purchased them, I had come down to those and a pair of Vandersteen Audios in the same general price range, and I thought the Snells compared favorably.

 

[Beave]

What speakers are they? You could always use a much more powerful amp than even 2x as long as you use some sense with the volume control, too.

Yes, you could use an amp that is 100x more powerful than the speakers' max power specs - as long as you use some sense with the volume control.

You could also use an amp that can only output 5 watts, but you'd need to use sense with the volume control here too, as you won't be able to play super loud without distortion from the amp.

There's really no need to 'match' a speaker's power ratings with the power of the amplifier.

The matching that needs to be done, if anything, is to make sure your amp has enough power to play the speakers to your desired volume levels without straining the amp (ie, pushing it to distortion/clipping).

And that's a good thing, because speaker power ratings are so vague that they're basically useless. The power that a speaker can handle - note, this is not the power that a speaker outputs - is related to the frequency, the duration, and the amplitude of the signal/music being played. Obviously there's no way to condense those into a single number or even a range of numbers. A tone at certain frequencies and power levels can blow a speaker driver in milliseconds. Another tone at other frequencies and the same power level can be played for seconds with no problem. A speaker might handle 100W no problem at 400Hz but not at 50Hz or at 3kHz. Or it might handle a signal fine for a few milliseconds, but if you play a continuous tone, eventually the driver will overheat and be destroyed. So, again, you can't condense that all down to a simple range of numbers.

 

[Beave]

Also, I should add, the "sweep and precision" of the volume control is not so much related to the amplifier power output. Assuming you're talking about an 'analog' style potentiometer volume control, it's all about the potentiometer itself and how its resistance changes with position.

Some volume controls are near 1/2 gain at the 9 o'clock position; they go up fast at first, then go up much more slowly afterwards.

Other volume controls don't hit 1/2 gain until around the 12 o'clock position, or even more.

Think of a car analogy: The engine is the amp. The gas pedal is the volume control. You could have a car with a 80 hp 4 cylinder engine mated to a gas pedal that is super sensitive and that puts the engine near full power with the slightest touch. Or you could have a 12 cylinder 500 hp engine mated to a gas pedal that you have to push nearly all the way down to get the engine to work hard.

 

[lovinthehd]

The specs from my second post were directly from Snell's spec sheet, so those are probably the "official" ones (their instruction manual was generic to care, wiring configs, etc. and contained no specs; I had cut and pasted the "suitable for..." amp language from Stereophile as I made the original post before making it home to look at the spec sheet).

I did note that the Stereophile review used two test amps, one of which output 250 Wpc/8 ohms or 500 Wpc at 4 ohms; I guess as much as anything, I don't want to inadvertently goose the volume of whatever setup I put together and cook the speakers.

I was always pleased with the speakers' sound quality even though they were at the more economical end of Snell's line before the company went belly up years ago. When I purchased them, I had come down to those and a pair of Vandersteen Audios in the same general price range, and I thought the Snells compared favorably.

Inadvertantly goose the volume? Drunken parties or something like that? That could be bad but generally your ears will tell you when things sound bad. A volume control on an avr is generally in .5 dB increments so it would take a healthy goose to put you in danger, plus many/most avrs you can simply set a max volume level to avoid problems. If you continue to use your current amps on the pre-outs I doubt you'll run across any volume issues you're not already accustomed to in any case.

 

[Verdinut]

The published amp power limit of 150 watts as indicated by the manufacturer, would mean that the speaker will accept a maximum instantaneous peak input power of 150 watts for a fraction of a second beyond which it will get damaged. It's definitely not continuous power.

 

[Beave]

"Accidentally" turning the volume up can damage the speakers just about regardless of what amp and amp power you have. An underpowered amp turned all the way up could clip badly and damage the speakers through that (probably frying the tweeters). An overpowered turned all the way up could over-power the speakers, causing over-excursion of the woofers and/or overheating of the tweeters. Either way, speaker damage could result.

There are countless arguments online about *which* of those two scenarios is *more likely* to damage your speakers. It can get complicated.

The best thing is, regardless of your amp power, don't turn it up to the point that there is noticeable distortion from the amp OR from the speakers. That's usually safe enough to keep things happy.

 

[CMcD-USC]

Inadvertantly goose the volume? Drunken parties or something like that? That could be bad but generally your ears will tell you when things sound bad. A volume control on an avr is generally in .5 dB increments so it would take a healthy goose to put you in danger, plus many/most avrs you can simply set a max volume level to avoid problems. If you continue to use your current amps on the pre-outs I doubt you'll run across any volume issues you're not already accustomed to in any case.

Unfortunately (or fortunately, depending on how you want to look at it), I am well past the point of drunken parties. My comment about inadvertently goosing the volume was more of a recognition that my early teenage daughter likely will be using the system as well, and although she's a pretty responsible kid who doesn't willfully test a lot of boundaries, she can be a bit careless/inattentive at times. I can just give her a safe volume cap that should cover me on that concern.

Temporarily, I am running the speakers off of a friend's older Marantz 7.1 AVR that I think outputs at either 50 or 60Wpc, so I should be fine (my AVR the I previously used with in-walls wouldn't allow bi-amping of speakers below 8 ohms using the surround backs and I'm in the process of trying to put together a new system, whether an AVR alone or with separate amp(s) for the front channels or a pre/pro and amplifiers to drive everything) now that I have the second pair of Snells to match the first).

To Verdinut's point about the speakers specs likely expressing capability to handle a maximum instantaneous peak input power of 150 watts, how dependent is that on the amplifier driving the speakers versus other factors (type of music being listened to, the source of the audio signal, etc.)? Stated a little differently, if the system is playing something that sounds un-distorted at a given volume over time (i.e., what sounds to be a reasonable volume) but has a momentarily loud passage that is atypical from the mix of the rest of the track, does the risk of damage due to exceeding the speakers' maximum instantaneous peak input power increase dramatically with a 300 Wpc amplifier relative to a 100 Wpc amplifier, or as a practical matter am I just looking at it incorrectly or posing a hypothetical that's unlikely to occur?

 

[Leemix]

Unfortunately (or fortunately, depending on how you want to look at it), I am well past the point of drunken parties. My comment about inadvertently goosing the volume was more of a recognition that my early teenage daughter likely will be using the system as well, and although she's a pretty responsible kid who doesn't willfully test a lot of boundaries, she can be a bit careless/inattentive at times. I can just give her a safe volume cap that should cover me on that concern.

Temporarily, I am running the speakers off of a friend's older Marantz 7.1 AVR that I think outputs at either 50 or 60Wpc, so I should be fine (my AVR the I previously used with in-walls wouldn't allow bi-amping of speakers below 8 ohms using the surround backs and I'm in the process of trying to put together a new system, whether an AVR alone or with separate amp(s) for the front channels or a pre/pro and amplifiers to drive everything) now that I have the second pair of Snells to match the first).

To Verdinut's point about the speakers specs likely expressing capability to handle a maximum instantaneous peak input power of 150 watts, how dependent is that on the amplifier driving the speakers versus other factors (type of music being listened to, the source of the audio signal, etc.)? Stated a little differently, if the system is playing something that sounds un-distorted at a given volume over time (i.e., what sounds to be a reasonable volume) but has a momentarily loud passage that is atypical from the mix of the rest of the track, does the risk of damage due to exceeding the speakers' maximum instantaneous peak input power increase dramatically with a 300 Wpc amplifier relative to a 100 Wpc amplifier, or as a practical matter am I just looking at it incorrectly or posing a hypothetical that's unlikely to occur?

If the loud parts sound stressed turn down a little until it doesnt. Different recordings/sources can be vastly different volume at the same number on the master volume dial and heavily compressed music is more taxing than something like classical.

Most AVRs have very easy to set max volume that can be used somewhat as a safeguard.

The easiest way to know is to always dial it down some if it starts to sound harsh or stressed and never ever start at high volume. For most people their ears say ‘no thank you’ before the speakers do, but ye, there are some who apparently hate their ability to hear.


Sent from my iPad using Tapatalk

 

[mtrycrafts]

...- as long as you use some sense with the volume control.

...

That could be the problem though.

 

[Verdinut]

To Verdinut's point about the speakers specs likely expressing capability to handle a maximum instantaneous peak input power of 150 watts, how dependent is that on the amplifier driving the speakers versus other factors (type of music being listened to, the source of the audio signal, etc.)? Stated a little differently, if the system is playing something that sounds un-distorted at a given volume over time (i.e., what sounds to be a reasonable volume) but has a momentarily loud passage that is atypical from the mix of the rest of the track, does the risk of damage due to exceeding the speakers' maximum instantaneous peak input power increase dramatically with a 300 Wpc amplifier relative to a 100 Wpc amplifier, or as a practical matter am I just looking at it incorrectly or posing a hypothetical that's unlikely to occur?

The question to answer is: How loud do you listen to music? It looks like you mostly listen to pop music and probably most of it is compressed to a great extent, in which case the risk of getting an outstanding peak is null. However, the average power input into speakers may be high.

The situation with classical music is quite different. Some recordings can have a dynamic range attaining over 30 dB, that means requiring an amplifier power output attaining over 1000 times the level of the softest passage. Those peak levels usually last a fraction of a second.

Driving your Snells with a 300 watt amplifier can be safe if you don't have a large listening room, your listening distance from the speakers is reasonable and you don't use excessive volume levels. As a matter of fact, there is more risk of damaging your speakers with a 100 watts amp that distorts than with a 300 watts amp putting out clean power.

 

[lovinthehd]

Unfortunately (or fortunately, depending on how you want to look at it), I am well past the point of drunken parties. My comment about inadvertently goosing the volume was more of a recognition that my early teenage daughter likely will be using the system as well, and although she's a pretty responsible kid who doesn't willfully test a lot of boundaries, she can be a bit careless/inattentive at times. I can just give her a safe volume cap that should cover me on that concern.

Temporarily, I am running the speakers off of a friend's older Marantz 7.1 AVR that I think outputs at either 50 or 60Wpc, so I should be fine (my AVR the I previously used with in-walls wouldn't allow bi-amping of speakers below 8 ohms using the surround backs and I'm in the process of trying to put together a new system, whether an AVR alone or with separate amp(s) for the front channels or a pre/pro and amplifiers to drive everything) now that I have the second pair of Snells to match the first).

To Verdinut's point about the speakers specs likely expressing capability to handle a maximum instantaneous peak input power of 150 watts, how dependent is that on the amplifier driving the speakers versus other factors (type of music being listened to, the source of the audio signal, etc.)? Stated a little differently, if the system is playing something that sounds un-distorted at a given volume over time (i.e., what sounds to be a reasonable volume) but has a momentarily loud passage that is atypical from the mix of the rest of the track, does the risk of damage due to exceeding the speakers' maximum instantaneous peak input power increase dramatically with a 300 Wpc amplifier relative to a 100 Wpc amplifier, or as a practical matter am I just looking at it incorrectly or posing a hypothetical that's unlikely to occur?

Well sounds like the max volume level setting will be something you'd want to employ....that Marantz probably has such. Keep in mind just because an amp is rated at say 60wpc at a given distortion level doesn't mean it can't exceed that with the right signal and volume setting.

I have had speakers blown by excessive power, on gear that had no max volume setting, by my roommate and business partner Old analog gear that didn't have that max volume setting feature, but if it had, that wouldn't have happened. Some partying was involved and had I been there it wouldn't have happened but I was working. He just wanted to see how loud it could get but knew little about my gear (which was somewhat fragile speakers with a ton of power).

As to passively bi-amping speakers with an avr, this might be of interest to you https://www.audioholics.com/frequent-questions/the-difference-between-biamping-vs-biwiring

 

[CMcD-USC]

The question to answer is: How loud do you listen to music? It looks like you mostly listen to pop music and probably most of it is compressed to a great extent, in which case the risk of getting an outstanding peak is null. However, the average power input into speakers may be high.

The situation with classical music is quite different. Some recordings can have a dynamic range attaining over 30 dB, that means requiring an amplifier power output attaining over 1000 times the level of the softest passage. Those peak levels usually last a fraction of a second.

Driving your Snells with a 300 watt amplifier can be safe if you don't have a large listening room, your listening distance from the speakers is reasonable and you don't use excessive volume levels. As a matter of fact, there is more risk of damaging your speakers with a 100 watts amp that distorts than with a 300 watts amp putting out clean power.

Thanks much for the insight. My listening space isn’t overly large (13’ X 21’) and the speakers are on the long wall, so the listening distance is 11ish feet (they‘re a couple of feet away from wall per mfg. recommendation). I listen to music at a fairly robust volume but nothing ear-splitting. The first discs I popped in my player when I got them back from the repair shop (had had disintegrating foam surrounds replaced) were a Stanley Jordan Blue Note recording and a classical guitar ensemble recording from my former instructor. I’m a guitar freak, so I wouldn’t characterize my listening tastes as bending to popular exactly (more traditional acoustic and electric blues and guitar-heavy prog), but a lot of it is non-classical/non-jazz, so the same dynamic limitation probably would be applicable to my standard playlist regardless.

I’ve been looking some at Marantz components and a bit at Emotiva. A local guy is trying to sell me on an Anthem AVR; my fundamental problem is that I haven’t really paid attention to this stuff for years, so I’m kind of in information overload trying to re-educate myself.

 

[Verdinut]

Thanks much for the insight. My listening space isn’t overly large (13’ X 21’) and the speakers are on the long wall, so the listening distance is 11ish feet (they‘re a couple of feet away from wall per mfg. recommendation). I listen to music at a fairly robust volume but nothing ear-splitting. The first discs I popped in my player when I got them back from the repair shop (had had disintegrating foam surrounds replaced) were a Stanley Jordan Blue Note recording and a classical guitar ensemble recording from my former instructor. I’m a guitar freak, so I wouldn’t characterize my listening tastes as bending to popular exactly (more traditional acoustic and electric blues and guitar-heavy prog), but a lot of it is non-classical/non-jazz, so the same dynamic limitation probably would be applicable to my standard playlist regardless.

I’ve been looking some at Marantz components and a bit at Emotiva. A local guy is trying to sell me on an Anthem AVR; my fundamental problem is that I haven’t really paid attention to this stuff for years, so I’m kind of in information overload trying to re-educate myself.

Should you have more questions, you may also find some answers through our search box, but if you have a specific question and can't find an answer for it, plesae don't hesitate to ask us and we'll be pleased to help in the possible.

 

[CMcD-USC]

Reading through the speaker manual a bit more, there is a short section on component selection. True to what you all have said, the manual does say that although the speakers will work well and produce sufficient volume with low wattage amplifiers due to their sensitivity, they are specifically designed for high-wattage amplifiers so as to accurately reproduce live acoustic music levels without distortion (and conversely, that the speakers aren’t designed to achieve the same levels for rock music).

 

[CMcD-USC]

Well sounds like the max volume level setting will be something you'd want to employ....that Marantz probably has such. Keep in mind just because an amp is rated at say 60wpc at a given distortion level doesn't mean it can't exceed that with the right signal and volume setting.

I have had speakers blown by excessive power, on gear that had no max volume setting, by my roommate and business partner Old analog gear that didn't have that max volume setting feature, but if it had, that wouldn't have happened. Some partying was involved and had I been there it wouldn't have happened but I was working. He just wanted to see how loud it could get but knew little about my gear (which was somewhat fragile speakers with a ton of power).

As to passively bi-amping speakers with an avr, this might be of interest to you https://www.audioholics.com/frequent-questions/the-difference-between-biamping-vs-biwiring

Thanks for the bi-amp info. Given the reference in the piece to passive bi-amping as "fool's bi-amping," are its documented benefits negligible enough not to bother with it unless I were employing an external crossover (the speakers' manual suggests the employment of a two-way electronic crossover and provides formulae for setting high and low pass frequencies)? At this point, I think I am going to separately amplify the front speakers whether I go with a pre/pro or AVR w/ front channel pre-out, but I'm trying to determine whether the money is better spent on a single nice stereo power amp or matching pair for the fronts.