• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Frequency Response - Bass Response

Shaun Kelly

Shaun Kelly

New Member
If the frequency response of a modern bookshelf speaker is 39 Hz → 40000 Hz (ie. the Polk Audio Signature S20), will it produce a similar bass response of a larger vintage speaker with a frequency response of 40 Hz → 22000 Hz (ie. Coral BX-805)?

[Am I asking the right question? New to the forum]
 
Register to hide this ad
Bass response will differ between speakers despite having a similar frequency response. I cannot explain the technical intricacies but, there's a lot of other factors to consider when understanding bass response.
 
mythless said:
Bass response will differ between speakers despite having a similar frequency response. I cannot explain the technical intricacies but, there's a lot of other factors to consider when understanding bass response.
Click to expand...
Understood.... Perhaps another way of putting this question is in theory could the bass resonance (?) of a small woofer match that of a larger woofer?
 
What matters is volume displacement, the area of the cone times the usable throw (Xmax)
and sometimes usable Xmax is well beyond the rated amount - sometimes not.
A small woofer with very long throw might have more volume displacement than a bigger
woofer with short throw.
If the T&S parameters of two different size woofers are the same then the frequency response
in the same sized box will be the same - in theory.
The Small Advent is a good example.
 
However there does seem to be a difference in character between large diameter/short throw and small diameter/long throw even when displacements are equal.

In reality no two speakers sound/feel the same even with the same specs. Two vintage speakers both using say 12" woofers and reaching to the same f3 often have totally different characteristics based on things like enclosure type and tuning as well as the individual drivers.

Each has different goals and compromises. That said I personally favor larger diameter when possible.
 
mashaffer said:
However there does seem to be a difference in character between large diameter/short throw and small diameter/long throw even when displacements are equal.

In reality no two speakers sound/feel the same even with the same specs. Two vintage speakers both using say 12" woofers and reaching to the same f3 often have totally different characteristics based on things like enclosure type and tuning as well as the individual drivers.

Each has different goals and compromises. That said I personally favor larger diameter when possible.
Click to expand...

You favor larger diameter because larger diameter typically means louder and/or more bass resonance; or you favor larger diameter for other reasons?
 
Nearly all speaker drivers soft clip, the distortion is fairly tolerable even up to 5 - 10%.
A small driver moving far will be in soft clipping before a large driver with similar throw.
There are modern advances such as an XBL motor that can get around this issue.

Also, the voice coil inductance is modulated by the motion so a driver with modern
shorting rings will have less intermodulation distortion due to the inductance variation.
A poorly designed large driver might do worst than a well designed small driver, it all
depends on many factors.

The Advent woofers are primitive but optimized in such a way that their distortion just
seems to fatten up the bass at high levels. The Xmech is very large so that they can
be overdriven hard before the voice coil bottoms with a crack sound.
 
It’s never apples to apples. The measurement criteria between manufacturers over decades are constantly changing. In general, a larger diameter driver will have more output at the extremes of its operating limits. More cone surface, means more air is moving. Modern drivers tend to have more compliant suspensions with more cone travel, allowing them to push a convincingly large amount of air at relatively high volumes. But there are other compromises. And you can ignore physics.

So there’s really no definitive way to answer your question. It’s all contextual.
 
Shaun Kelly said:
If the frequency response of a modern bookshelf speaker is 39 Hz → 40000 Hz (ie. the Polk Audio Signature S20), will it produce a similar bass response of a larger vintage speaker with a frequency response of 40 Hz → 22000 Hz (ie. Coral BX-805)?

[Am I asking the right question? New to the forum]
Click to expand...

The other very basic question you should be asking is what is the dB tolerance on the spec 39 to 40K +/- 1 dB or +/- 6 dB or whatever?
The nice thing about the Large Advent woofer is that it is only about 2 dB down at 42 Hz because
Qtc is about .8 - .9. Many other designs that reach to the low 40s are -3 or even much further down.
The Small Advent is about -0dB at 45 Hz so it also reaches very deep and flat.

If their distortion, compression, and frequency response are the same then they should sound the same - it ain't rocket science. Getting them all the same is not simple or easy.
 
Last edited:
Pete B said:
The other very basic question you should be asking is what is the dB tolerance on the spec 39 to 40K +/- 1 dB or +/- 6 dB or whatever?
The nice thing about the Large Advent woofer is that it is only about 2 dB down at 42 Hz because
Qtc is about .8 - .9. Many other designs that reach to the low 40s are -3 or even much further
down.
The Small Advent is about -0dB at 45 Hz so it also reaches very deep and flat.

If their distortion, compression, and frequency response are the same then they should sound the same - it ain't rocket science. Getting them all the same is not simple or easy.
Click to expand...
Thanks for all your input Pete. Very helpful.
 
Polar response has a lot to do with it.

To sound similar in use, two different loudspeakers will have to have very similar polar responses.

Very few manufacturers will post the polars for their speakers as they're often un-flattering and will reveal the directivity issues most cone type speakers suffer.
 
Shaun Kelly said:
You favor larger diameter because larger diameter typically means louder and/or more bass resonance; or you favor larger diameter for other reasons?
Click to expand...

I am not as into insane volume levels as I once was. :D In general I find the larger drivers seem to (all else being equal which it rarely is) have a more relaxed, less stressed presentation. They tend to sound more natural to me.

I guess it is kind of like a 428 V8 and a 1.5liter double turbocharged I4. Both may get the job done but the 428 doesn't have to work as hard.

It is not a hard and fast rule buy any means but it seems like a general trend.
 
Pete B said:
What matters is volume displacement, the area of the cone times the usable throw (Xmax)
and sometimes usable Xmax is well beyond the rated amount - sometimes not.
A small woofer with very long throw might have more volume displacement than a bigger
woofer with short throw.
Click to expand...

Pete,
I have appreciated your contributions for a couple of years now and wanted to say..... Thank you!
Jef
 
Depending on the manufacturer the tolerances could be +/- 3 db, +/- 6db or +/- 10 db. In the old days its was normally +/- 10 db. Klipsch in an anechoic chamber was closer to +/- 3 db. And How a speaker performs in test space can be a lot different in a home. So no how the speakers are tested. My speakers run about +/- 6db before using a room EQ. Now its almost +/- 2 db from 25 to 4000 with a slight roll off to - 6 to - 8 db at 18,000. A few clicks on the treble control and they are most flat to 20,000. But I don't like that bright of sound. Highs normally drop 8 to 10 db in live un-amplified concerts at 10 to 20 kHz.
 
^^ I was going to post what twiiii said. To carry that a bit farther, let's say you have two speakers with similar frequency response ratings. If they are both really flat speakers - let's say +/-3 db across the entire spectrum, which is fairly impressive - you'd think they would sound the same. But even that tight of a range allows for one speaker to be -3db at a given frequency while the other is +3db, resulting in a 6 db difference in volume between the two speakers. 10 db is a factor of 2 in perceived volume (even though it takes 10x the amp power). No two speakers have identical curves and there will be peaks and dips and humps and valleys in different places. You would surely notice a difference in a snare drum (for example) if the volume were double or even 1.5 times higher in one speaker compared to another. Taken as a whole, over the entire sound spectrum, this can have a dramatic effect on the overall sound of the speakers. Add to that, room response (resonance modes), off-axis response, dynamics, etc. and it's no wonder that two speakers both rated with the same "39Hz-20 KHz" frequency response will sound completely different.

That's why you always should listen to speakers to know whether you're going to like them. Specs can only go so far.
 
Last edited:
Thanks all for the input... although, this has become sort of a moot point for me as I found two sets of speakers at a price too good to pass up: Phase Technology V-12's and Phase Technology V-10's.
 
The more speakers you delve into, the more important this stuff becomes as far as understanding what you are hearing. :thumbsup:

Rock on! :rockon:
 
You must log in or register to reply here.
Back
Top Bottom