Speaker Frequency Response Comparison

So if you are looking at two speakers to purchase and one has a frequency response of 38 to 26 and the other 50 to 18, (+/- 3db) would the 38 to 26 have potential to out-perform the other speaker?

 

Only your ears will give you the correct answer for this question. Are you using a subwoofer for freq's below 50hz? It will be very room dependent as well. Is your room untreated and leaning toward brighter sounding? Too many factors are in play here, a home audition is a must!

 

But all factors being equal wouldn't a speaker that can go much lower and much higher be a better speaker?

 

Theoretically, yes. It will still depend on how different speakers interact with your room and the gear you are using.

 

First thing you need to find out is if the two speakers were measured with the same equipment and methodology in identical rooms. Speaker measurements aren’t standardized, you have to be careful when comparing them. Then there is the issue that speakers will sound and measure differently from room to room.

 

Assume all other factors are equal. Take all other variables out of consideration. Just use frequency response.

 

Everything being exactly equal, you would be correct but only on paper. Your ears may tell a different story. What sounds great to me might not sound great to you. Audio is very subjective, everyone hears differently.

 

Extension is one consideration. What about frequency response accuracy?

One speaker might be able to reproduce the lowest lows and the highest highs, but have some frequencies exaggerated. Another might have a narrower range but be ruler flat.

 

Interesting that some highly regarded "musical" east coast sound speakers of bygone days had these frequency responses:

Dynaco A10 50 to 15
Dynaco A25 30Hz to 15kHz
AR 4x 45 to 20

 

A manufacturer can state its specs to be anything they want them to be.

 

WHERE do you see the REAL laboratory frequency response graphs of ANY loudspeaker you are looking at? To make your choice.

As for me, I see such VERY rarely. Even for the so-called “studio monitors”. Since the era when I bought and owned successively two pairs of 3-way floor standers made by mfrs with a great name. Every LS unity (not a pair of) was accompanied with a manual containing the model’s laboratory frequency response graph. Not only “numbers” that may express no one knows what.

Do you see such EVERY TIME you are choosing a LS?

 

Assume they're correct for purposes of this thread.

 

The specs don't say anything until you look at graphs. Smoothness and general trend of the response within the 6 dB window (represented by +/- 3dB) mean a lot more, in terms of naturalness of sound, than ultimate extension. For example, a frequency response (FR) that rises 6 dB from bass to treble will sound terribly screechy and bass-shy, especially if there are peaks in the midrange and treble. An in-room FR that slopes down smoothly 6 dB from bass to treble could sound wonderful, especially if the mid and treble ranges are free of notable peaks, especially broad ones (as they are more audible than narrow ones). In that connection, a peak of say +2 dB anywhere in the range 1 kHz to 8 kHz or so can be quite audible and irritating. In listening to piano music, soprano, violin, or cymbals, even smaller peaks can be distracting, IME.

 

Unit, of course, not unity.

 

I guess it would depend on what we considered equal. Unfortunately, using the on-axis frequency response as a single reference does not provide enough information on how well a loudspeaker will perform. The following lecture by Dr, Floyd Toole (starting at 21:35) discusses the relationship between on-axis and off-axis measurements and how they shape the actual sound that we hear.

 

Here's an example where the better-appearing spec may not be the better-sounding:

38-26kHz +/-3dB:


50-18kHz +/-3dB:


These hand-scribbled examples are going to sound very different.

The first example would be colored both boomy and tinny, while the second is better than any real-world speaker actually might deliver.

Any spec +/- 3dB within the passband is exceptional for a speaker though. Your room is not +/- 3dB.

After receiving the response graph obtained from (independent, third party?) testing, the manufacturer can tweak the specs how they want, stating for example +/-5dB when no adequate-looking specs can be fit within 3db. They also might just fit the graph between +/- instead of comparing the -3dB point to the average output.

 

The printed/stated frequency response of a speaker tells you almost nothing about how the speaker will sound. Most designers will tell you it's just about the most useless specification there is. My belief is this holds true for cartridges too.

 

How would one determine sound quality or timbre from a frequency response? I play a stringed instrument and the reproduced quality of such an instrument, on the same recording, varies between speakers I've heard. I am fairly sure the best 'sound' to my ears (important) has not correlated positively with the frequency response of the speaker, but I have never tested this. Obviously, the OP stated the caveat 'all other things being equal' so this is an interesting hypothetical question.

 

So the frequency response tells you how low it goes into bass and how up in frequency to treble, but may sound bad if it can't reproduce those sounds well. As in it goes down to 38hz but if it jumps around 6db here and there it will sound awful, but a speaker only going down to 50hz but that is smoother will sound better/ more musical even though it's missing the 12hz that the other one gets down too.

 

One of the easiest ways to familiarize yourself with the contributions of different frequencies and how they effect the total sound is to play around with a graphic equalizer, which can be software based (grab WinAmp) if you don't have a hardware one.

Take a particular band, and turn it to extremes in boost and cut, and you can become familiar with the type of adjective you'd call that frequency range. See how little it takes for you to notice a change in sound character. Dial in a graphic representation of a response curve, and you can toggle to see in what direction that pushes to tonal character.

Another Winamp plugin, Equalizer by Nevi, allows you to draw your own response curve on a 250 band EQ:

 

That is a very good illustration of what I was trying to convey in my post. The +/- 3 dB can sweep a lot that's important under the rug.

FR is a great deal of what determines timbre. In a graph, look for smoothness and perhaps a 3 dB to 6 dB decline over the frequency range. Low distortion helps, too, but that's not FR. Big peaks and dips in the FR will distort timbre. A rising high end will make the sound of high-pitched instruments and voices too aggressive.

Among other things that affect timbre are the quality of the recording and quality of the other gear, as well as the listening environment.

If you are seriously interested in the question, you could read this essay by Robert E Greene and others on his site. Besides being an audio critic and professional (PhD) mathematician, he is a semi-professional violinist.

 

Yes, pretty much. Also, increasing response with frequency usually sounds bad, too.

 

Maybe at the the frequency extremes, though just known the -3dB points at he frequency extremes doesn't tell you very much about how a speaker is going to sound (nor how the specs were arrive at), though a speaker that's -3 dB at 50 Hz might be one that leaves some common bottom end fundamental frequencies behind.

 

All else being equivalent the 38 and 26 speaker is superior provided both speakers measure the same from 50hz-18khz. Deeper bass response is generally always desirable as it basically serves as the foundation of music - bass matters and it matters a lot. Most people above 40 have touble with frequency response above 15khz so the latter number doesn't matter as much. In fact the frequency response standard for many many years was 40hz-15khz and that makes some sense - little music goes below 40hz and few people hear above 15khz and what is above 15khz isn't typically that important to hear.

Frequency response is one of many many factors of a speaker system - tilt your head one inch to the left while listening and the frequency response at your ears (the only place frequency response matters) will change. The room and set-up have dramatic affects on frequency as well. Speakers with less bass are typically easier to set-up as the old saying Big bass causes big problems (like big speakers cause big problems). Not insurmountable but in some rooms insurmountable. And that saddest part is that the places most people go to evaluate products - dealer showrooms, and audio shows typically have the worst rooms in terms of power supplies and quality of construction and the latter place has the least amount of time to be properly set-up.

I remember auditioning Soundlab at an audio show several years back - they were given the wrong room - small one for their HUGE speakers and the sound - well to be nice was very poor. And then people come on forums blasting away - they suck what overpriced crap - my $2k speaker sounds better and so it goes.

I would say the problem with some of this is the experience - Paradigm (a Floyd E Toole favorite design) sold the Studio 40 standmount which claims 40hz -2db or some such thing. I have a set of Wharfedale Vanguards - based on the now classic E-70) which is a 70 litre floorstander with a 10 inch woofer and 95dB sensitive. This speaker also claims 40hz.

You listen to both speakers at the same loud levels (any music) and there is no question to anyone who has heard these two side by side that the Wharfedale has real impact feeling bass and the impression the band or orchestra is in the room playing. It doesn't measure as well - I have no doubt about that but the Wharfedale has significant feeling bass and the Paradigm (or the vastly more expensive Totem Mani 2) do NOT. This is where other factors come into play - the dynamic scale factor and the ability to present a visceral sense of the event.

My reaction to most Solid State equipment and most Harman International (Floyde Toole inspired narrow baffle speakers) is represented well in this cartoon - I am the cat listening to narrow baffles and solid state.

 

You cannot use just the direct anechoic frequency response to judge a speaker; you also need the in room power response. Drivers radiate in all directions and a speakers direct sound may include compensations for the radiated sound. So even if the direct anechoic measurements does not look good, the frequency curve at listening position may be much better.