Speaker frequency response

Gaz37

Well-known member
Sep 23, 2014
58
0
10,540
Visit site
I'm struggling to find any correlation between the published frequency response for a speaker & what they actually sound like.

I currently have three pairs of standmount speakers (itchy bidding finger) B&W 600i, AE Aevis evo 1, Monitor Audio Bronze 2 with (lower) frequency responses ae follows -

B&W- 80hz

AE- 50hz

MA 45hz

So according to the figures the Monitor Audios should have the best bass and the B&W the worst, but in real life the opposite is true. The MAs have no no audible bass whatsoever (in fact they are possibly the worst speakers I have ever heard) and the B&Ws have easily the lowest bass.

How can this be?
 

BigH

Well-known member
Dec 29, 2012
115
7
18,595
Visit site
Gaz37 said:
I'm struggling to find any correlation between the published frequency response for a speaker & what they actually sound like.

I currently have three pairs of standmount speakers (itchy bidding finger) B&W 600i, AE Aevis evo 1, Monitor Audio Bronze 2 with (lower) frequency responses ae follows -

B&W- 80hz

AE- 50hz

MA 45hz

So according to the figures the Monitor Audios should have the best bass and the B&W the worst, but in real life the opposite is true. The MAs have no no audible bass whatsoever (in fact they are possibly the worst speakers I have ever heard) and the B&Ws have easily the lowest bass.

How can this be?

I would ignore figures. It can depend on the amplifier as well. B&Ws are generally quite bassy but I don't find them accurate or natural. MAs do get a mixed response.
 

BigH

Well-known member
Dec 29, 2012
115
7
18,595
Visit site
Gaz37 said:
I'm struggling to find any correlation between the published frequency response for a speaker & what they actually sound like.

I currently have three pairs of standmount speakers (itchy bidding finger) B&W 600i, AE Aevis evo 1, Monitor Audio Bronze 2 with (lower) frequency responses ae follows -

B&W- 80hz

AE- 50hz

MA 45hz

So according to the figures the Monitor Audios should have the best bass and the B&W the worst, but in real life the opposite is true. The MAs have no no audible bass whatsoever (in fact they are possibly the worst speakers I have ever heard) and the B&Ws have easily the lowest bass.

How can this be?

I would ignore figures. It can depend on the amplifier as well. B&Ws are generally quite bassy but I don't find them accurate or natural. MAs do get a mixed response.
 

Gaz37

Well-known member
Sep 23, 2014
58
0
10,540
Visit site
So why publish them if they mean nothing? Surely they aren't just made up and must be measured somehow?

The MA Bronzes are shockingly bad, they sound like the little plastic boxed speakers that come with Currys micro systems, what little bass there is sounds like somebody banging on a cardboard box.
 

gasolin

Well-known member
Gaz37 said:
I'm struggling to find any correlation between the published frequency response for a speaker & what they actually sound like.

I currently have three pairs of standmount speakers (itchy bidding finger) B&W 600i, AE Aevis evo 1, Monitor Audio Bronze 2 with (lower) frequency responses ae follows -

B&W- 80hz

AE- 50hz

MA 45hz

So according to the figures the Monitor Audios should have the best bass and the B&W the worst, but in real life the opposite is true. The MAs have no no audible bass whatsoever (in fact they are possibly the worst speakers I have ever heard) and the B&Ws have easily the lowest bass.

How can this be?

It doesn't mean the bass is best from the ma just because it goes down to 45hz (lower than the to other speakers) like a car that not always has the best handling because it has more horsepower then the other cars you compare against, it's not logical to asume the amp with the highest wattage has the best sound.

It's not necessarily the speaker with the lowest bass that has the best bass
 

james_LR90

New member
Aug 17, 2010
1
0
0
Visit site
Gaz37 said:
So why publish them if they mean nothing? Surely they aren't just made up and must be measured somehow?

The MA Bronzes are shockingly bad, they sound like the little plastic boxed speakers that come with Currys micro systems, what little bass there is sounds like somebody banging on a cardboard box.

 

They publish figures because figures sell product even if they are false. There are a lot of people who purchase hi-fi purely on quoted figures not on actual sound!
 

BigH

Well-known member
Dec 29, 2012
115
7
18,595
Visit site
Really figures are not that reliable, you only have to compare amps. As I said it also depends what amps you are using, some speakers with low power amps will sound bad. At best its just a rough guide, americans love these sorts of things. Its best to hear them yourself, probably set up. I never even looked at figures when I was testing speakers. More important is how they work in your system and room.
 

BigH

Well-known member
Dec 29, 2012
115
7
18,595
Visit site
Really figures are not that reliable, you only have to compare amps. As I said it also depends what amps you are using, some speakers with low power amps will sound bad. At best its just a rough guide, americans love these sorts of things. Its best to hear them yourself, properly set up. I never even looked at figures when I was testing speakers. More important is how they work in your system and room.
 
Lower limits quoted in spec sheets can mean almost anything. They might be measured in different circumstances, at different levels, or with different dB limits. 50Hz is quite low enough from a small speaker, if it is tailing off smoothly. It might have a big hump at 80Hz, which might extend the lower limit, but won't sound good.

Only independently tested results from a trusted source can be of some help, but in practice they give precious little clue about the overall sound. They can identify weaknesses, which may be audible. In some cases, careful placement and other measures can ameliorate these.
 

Blackdawn

Well-known member
May 7, 2010
88
1
18,545
Visit site
Gaz37 said:
I'm struggling to find any correlation between the published frequency response for a speaker & what they actually sound like.

I currently have three pairs of standmount speakers (itchy bidding finger) B&W 600i, AE Aevis evo 1, Monitor Audio Bronze 2 with (lower) frequency responses ae follows -

B&W- 80hz

AE- 50hz

MA 45hz

So according to the figures the Monitor Audios should have the best bass and the B&W the worst, but in real life the opposite is true. The MAs have no no audible bass whatsoever (in fact they are possibly the worst speakers I have ever heard) and the B&Ws have easily the lowest bass.

How can this be?

It is probably best to combine several specs of the speaker to give you an idea of how you think it will sound before auditioning and to help short-list to find the speaker that best suites your taste, room size and preferences. In general it is useful to know some basic information about a speaker, such as cabinet volume, driver size/number, power and frequency range. I've heard the MA BX2 (diff. model) and if anything they had too much bass. Again depends on the room size and lots of other factors like distance from the walls and volume you play at.
 

davedotco

New member
Apr 24, 2013
20
1
0
Visit site
First of all we should discriminate between the figures that are quoted by some manufacurers for marketing reasons, they are, by and large, complete nonsense and genuine measured response, meaured according to accepted practice.

Generally, this requires the speaker to be measured in anechoic conditions, at a specified distance, on axis and at various power levels. With thise criteria clearly stated it is possible to draw some conclusions from the measured response. The more comprehensive the measurements the more accurate the conclusions will be.
 

Benedict_Arnold

New member
Jan 16, 2013
661
3
0
Visit site
Speaker frequency response is measure under standard anechoic conditions (or, at least, it shoudl be) using a pure sine wave input. The frequency of the sine wave, for a fixed amplitude (and thus power delivery / consumption) is changed from near zero to 20, 30 or even somethines 50 kHz, depending on the manufacturer and how diligent that manufactuer is in testing tis speakers.

What you should be looking for is a relatively flat line frequency response from 20 Hz to 20 kHz, which are regarded as the "normal" frequency range of the human ear, although we all tend to loose higher frequency perception as we get older. Any sudden spikes or troughs will indicate a harmonic problem, that is, the speaker cone(s) or something in the circuit is operating at or close to its natural frenquency of vibration. A speaker cone can have all sorts of different natural frequencies, depending on the mode shapes of the cone, ranging from the simple in-out movement of the cone to really really complicated ones with two, four, six, etc. different hot spots of vibration.

The linkey below is to an MEng dissertation, where the student was using finite element analysis to explore these mode shapes (quick explanation, the eigenvalues of a finite element analysis stiffness matrix correspond to the natural frequencies of the speaker cone, and from these one can calculate the mode shapes - the shapes the pseakers would look like if instantaneously frozen in time - look like). It's all highly testicle, but take it from a one time FEA engineer, it's true.

Linkey:

http://www.ewp.rpi.edu/hartford/~ernesto/SPR/Miller-FinalReport.pdf

The electronics in the crossovers can also have natural frequencies that can cause spikes or drop-offs. One of the eraly arguments for bi-amping / bi-wiring was that badly designed crossovers could / would / did leave gaps where the signal was in the range where it was too hig for the LF side and too low for the HF side, so feeding the full signal to both woofers and tweeters avoided such drop-offs. Mostly, good modern speakers and their crossovers don't suffer from that so much these days, but some speakers still do sound better bi-wired or bi-amped.

Any drop more than 3 decibles (dB) represents a halving of sound output, so you shouldn't be looking at speakers with drop-offs more than this in the 20 to 50 kHz range or above, say, 15 to 18 kHz and above.

Now. All of that is about how much sound is produced, not about what that sound, erm, sounds like. The tests are done with a regular, fixed, sine wave. They take no account of a moving frequency with sudden thump-a-thumps from a bass drum or the huge dynamic range of, say, a virtuoso rock guitarist's solo. That's when things like the dynamicity or sensitivity of the speaker come into play. Moreover, the speaker still isn't being fed a pure sine wave, rather a series of overlapping waves, that could confuse the speaker. Also, how much power is being fed to the speakers has its effect. That's usually measured as sensitivity also. I once had a pair of Mordaunt-Short MS15 speakers which sounded as flat and dull as you can imagine, until you cranked up the volume to neighbour annoying levels. Then the woofers started not only to vibrate, but to visibly move in and out on their rubber diaphragms. At that point the speakers came alive.

Bottom line: maths is great, but your ears are your master. And you need an amplifier with enough "oomph" to drive your speakers properly.
 

Benedict_Arnold

New member
Jan 16, 2013
661
3
0
Visit site
nopiano said:
Was that your spell checker, Benedict? "It's all highly testicle..." Or was that your way of saying it is all boll**ks?!

Technical or testicle, it's all in the understanding. To the lay man, it may indeed be mens' dangly bits, but if you know what you're looking at, and assuming the kid got his input data right, the results stand up.

FWIW the first Sleipner platform in the North Sea, six hundred thousand tonnes, yes 600,000 tonnes, of concrete, imploded because someone did a lousy finite element analysis job. When the concrete hit the bottom of the fjord the platform was in waiting to be towed out, it cause a magnitude 7 on the Richter scale earthquake!
 

lindsayt

New member
Apr 8, 2011
16
2
0
Visit site
Really good post from Benedict_Arnold. Especially the bit about frequency response not telling you about the quality of sound at any particular frequency.

Coming back to the original post. The discrepancies in the listening vs the quoted bass extension figures are most likely caused by:

No -db figure quoted. We don't know if those frequencies were -3, -6, -9, or -12 dbs below nominal output?

Also some manufacturers may be using anechoic figures, others in-room. With the in room figures I often wonder what sort of room and where in the room they're placed. With some of them seeming to get 12 dbs of room reinforcement of the bass! Might be possible with the speaker on the floor in the corner of a bathroom.

And it has be known for some manufacturers to claim specifications that vary a lot from measurements made by a reputable independent source.

When auditioning speakers I quite often find myself drawing a frequency response curve in my head. These usually have some resemblance to actual measured responses.

There's the dome. The smiley face / banana. The double camel hump. The Humber Bridge. The flat enough.
 

TRENDING THREADS

Latest posts