I guess it should be noted that measurements are made in "anechoic" chambers which are not like most listening spaces. (I would say any but someone will find an objection).
Also that human hearing is supposedly limited to at best 20Hz to 20KHz. As you age you lose some of the upper frequency hearing ability. Many argue that higher frequency overtones etc. can still be percieved in some way, making the extended upper frequency response from the speaker meaningful. I don't know if it does or doesn't.
What you will find is that most speakers don't give you the lowest frequencies as I and several others have noted.
Finally the specs really don't matter all that much. If I told you the horsepower of a car, absent of anything else, especially test driving it what good is it? You understand my point I'm sure. Go out and listen if you can is my advice and don't get to caught up in the specs for anechoic chamber responses. If I had one spec to focus on it would be sensativity which is important because it tells you what kind of amp you'll need to drive them. |
Linear, in this case does not mean flat. |
I like a speaker to have response down to at least 40hz and 30hz is even better and high end is a non issue for me, they have all been good no matter what the spec.
more important is speaker tonal balance and if the speaker works in YOUR room.
as a general guideline I hope this helps |
>11-01-12: Drew_eckhardt
>The right fix (which works in more rooms and doesn't cost you detail which comes from the direct sound level) is more driver + baffle combinations sized appropriately for the wavelengths being reproduced although that is more expensive.
Wave guides and dipole cancellation which increase acoustically small driver directivity for a better match to the lower frequency driver are other solutions which work well. |
>11-01-12: Realremo
you might hear speakers' mid-range being described as "ruler flat" across a certain frequency spectrum. That basically means there are no peaks or valleys in the response that affect the lows, mids or highs. This is my understanding of what linearity is.
This is still meaningless because our brains perceive timbre as a weighted combination of the spectra from what they believe to be a direct sound and its reflections where we expect decreased high frequency content in the delayed signals (nature absorbs and diffuses more at high frequencies because objects like grass blades and rock surfaces are becoming acoustically large) and do not perceive local maxima in spectral content vs frequency as natural sounding.
Traditional speakers with a 6-8" mid-range drivers crossed to dome tweeters around 2.5 KHz have such a maxima as they transition from the midrange that's becoming acoustically large and starting to beam to the tweeter that's acoustically small and radiating hemi-spherically regardless of how flat they are on-axis with the resulting sound being harsh in situations with nearby untreated walls and ceiling.
Designers can and do compensate for the excess off-axis energy with a notch around the cross-over point like the BBC dip which makes the speaker perceptually flatter although it no longer measures this way.
The right fix (which works in more rooms and doesn't cost you detail which comes from the direct sound level) is more driver + baffle combinations sized appropriately for the wavelengths being reproduced although that is more expensive. |
you might hear speakers' mid-range being described as "ruler flat" across a certain frequency spectrum. That basically means there are no peaks or valleys in the response that affect the lows, mids or highs. This is my understanding of what linearity is.
Be careful of specs that say "+/-6dB" in the frequency response. my Quad 22L2s are spec'd down to 30Hz, but on a +/-6dB axis. In my room, auditioned with test CDs and music, I doubt they'd rate much below 38-40Hz on a +/-3dB axis. They certainly don't produce as much bass as my cheaper monitor audio Bx5s, but I still love the Quads' soundstage and mid-range sound.
There are other things to consider besides frequency response, like sensitivity, it's important because it affects which amp you pick. Those Tannoys might be easier to drive than most. |
Abbys and a NSM15EXP sub hooked up in parallel to speaker taps provides me a full spectrum without a xover. |
I am considering Tannoys
93 d/b sensitivity, frequency range of 29hz-22khz @ 6d/b
PS....After a lot of research I have never heard the term linearity until this post. |
You can't simply isolate the speakers. Are you listening to 'test tones' or music. My speaker have neither a great F Response nor linearity, but many who have heard them would say they're musical. The partnering equipment says a lot about the FR is heard. |
Music is made up of a lot of frequencies that by themselves (like a 20khz test tone) may be inaudible, but because it's music, they have a large effect on the sound. High notes can have higher overtones that sweeten the tone overall...most likely why analog (and live music) sounds different than digital, and why a good subwoofer can "charge" a room and make music that otherwise seems to lack low frequency information (mandolins?) sound more natural. |
I was also in the camp of single full range driver(no crossover) midrange is the King....until one day I realized that music is full spectrum, means you need highs and you need lows, even the super lows to have the full picture....now I am JBL 4350 guy.....so more is better. Go for the most extended and most sensitive you can get. |
1) You probably can't hear above 16KHz on music
2) The lower bound is what the speaker will reproduce at a low level, not what it will reproduce at a useable output level so it's meaningless. |
Vapor1, actually published specs can give one a ball park idea of room interaction, of course one would need the specs of the room as well. |
I think +/- 3dB is the standard way of expressing the linearity of the frequency response, and if you did not quote the deviation in your 30-30k spec, I'm going to assume it. You are doing well if your speakers are only down 3dB at 30Hz - that's very nice bass response. Mine don't go that low.
I am more enamoured by speakers that are efficient (say greater than 92db/w/m) and present an easy impedance load to the amplifier - say not under 10 Ohms.
Then again, I like low power amps.
Regards, |
I'll try and help. Manufacturers don't tell you all the specs such as +/- 3db linearity. You will find that type of data in a review of the speakers.
A typical floorstander may have freq. response of 34hz-20khz, but sensitivity should be high, around 88 or 90 dB ; that would be an efficient spkr.(easy to drive and can get very loud in a small room).
Also, a 4 ohm spkr will need a more powerful amp than a 8 ohm spkr. Then you need to be aware of the crossover fequencies of each driver.
I suggest start reading speaker reviews and how the specs are being measured. Hope that helps a bit. |
I also realize that my original post wasn't the best....but I can't go back and edit it. Also to some of you, I think you need to cut a little slack. You're right I don't know as much as you about this stuff....that's why I'm here. |
OK folks, let me back up a bit. I'm trying to get a sense of certain sets of speakers (I don't have the luxury of going and listening to a lot). My old speakers, which were floorstanders, had a range of 38hz-20khz (good, average???). So as I;m specing new speakers, I'm just trying to get an idea of a "comfort" zone in terms of range....I have seen floorstanders at the low end anywhere from 20hz-40hz, and at the top end anywhere from 20khz-100khz.....but there is usually a sweet spot that most fall into. That is the sort of thing that I'm trying to figure out. I realize it's not the best way to go, but in my situation I am buying everything "deaf" so to speak. As far as the D/B I'm finding a number of companies only give you the range, not the D/B. |
I find it ludicrous that people can't just give you an answer. It should be noted that linearity is very important but you didn't ask for that information. The OP asked for guidelines in regard to frequency response. Addressing linearity is FAR more important that upper/lower extension, and is equally relevant. So that is answering his question. As a guideline, deviation from flat is the spec that should be focused upon. Please consider that the frequency response should be accommodated by the room in which they will be placed in. True, room interaction is important ... but there's no way to determine that from a published spec. |
Please consider that the frequency response should be accommodated by the room in which they will be placed in. |
I will go out on a limb and just tell you that 20Hz-20KHz reasonably linear i.e. +/- 3Dbn is fairly standard fora large floor stander. My Focals actually don't extend done to 20 cycles but stops around 27 Hz. I don't miss it but some people like the vibration that a subwoofer typically provides. I find it ludicrous that people can't just give you an answer. It should be noted that linearity is very important but you didn't ask for that information. |
I agree with Plato but would like to add - Specs are just a guideline. Go and listen then make a decision from there. As far as a standard? For what - a desktop speaker or a 7' floorstander? Also +/- db can be all over the entire spectrum and without a graph with a known load you can't just assume it's at the high and low end. |
30Hz to 30kHz is not standard, although it is good. It is also meaningless without qualifying it with +/- however many dB's.
You should do some reading because you clearly don't understand this or how it would relate to sound quality. But generally, a vague spec like you proposed is meaningless. It tells you nothing about the linearity and nothing about how many dB's the response is down at the frequency extremes... |
Extension at either end is less important than linearity in-between. Meaning the amount of +/-, or how 'flat' they measure. Personally I'd say at most +/- 3db over it's operating range, and +/- 1.5db being what I insist upon myself. |
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What type of component are you asking about? |
