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Graham Audio LS5/9

Yank said:
I'm saying speed by definition is a high frequency phenomenon.
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Do you know what frequency range is included in the bass? I'll explain it to you. Bass is the frequency range from 16 to 250 hertz. Some sources write that the upper bass is in the range up to 320 Hz. Now try to find any tone generator online and put there a frequency of e.g. 170 Hz. For example here
https://www.szynalski.com/tone-generator/
You will hear it very well. Now try to stop and play quickly. Can you change the speed? Can you hear it?
 
Peter_Tos said:
I'll explain. In the Harbeth m40 speakers, the midrange is reproduced by an eight-inch Radial driver, it's in the middle between the tweeter and the bass driver. This Radial driver inside the cabinet has its own volume. That is, there is a small box attached to the front of the enclosure from the inside, in which the midrange Radial driver runs. You can see pictures of how this is set up in various reviews on the Harbeth m40. The rest of the cabinet is for the bass 12" driver. It needs a lot of volume and is slow. And the midrange Radial driver is fast. And it turns out that the midrange in the Harbeth m40 is faster than in the Harbeth shl5plus, where the Radial driver has to play both midrange and bass, so it runs the entire volume of the speaker cabinet.
Click to expand...

What do you mean by "slow/fast"?
 
Peter_Tos said:
Do you know what frequency range is included in the bass? I'll explain it to you. Bass is the frequency range from 16 to 250 hertz. Some sources write that the upper bass is in the range up to 320 Hz. Now try to find any tone generator online and put there a frequency of e.g. 170 Hz. For example here
https://www.szynalski.com/tone-generator/
You will hear it very well. Now try to stop and play quickly. Can you change the speed? Can you hear it?
Click to expand...

Perhaps it's a language barrier issue but I have no idea what you're trying convey here?!
 
Peter_Tos said:
Do you know what frequency range is included in the bass? I'll explain it to you. Bass is the frequency range from 16 to 250 hertz. Some sources write that the upper bass is in the range up to 320 Hz. Now try to find any tone generator online and put there a frequency of e.g. 170 Hz. For example here
https://www.szynalski.com/tone-generator/
You will hear it very well. Now try to stop and play quickly. Can you change the speed? Can you hear it?
Click to expand...

If a speaker is capable of reproducing 250-320Hz, then it is certainly "fast" enough to play anything lower than that.

Can you still hear your supposed "speed" in a woofer if you kill everything above 320Hz? If you compare two woofers can you tell which one is faster, if you listen to them through a 320Hz low-pass filter?
 
ToTo Man said:
Perhaps it's a language barrier issue but I have no idea what you're trying convey here?!
Click to expand...
I don't think the language barrier is the issue.
I was responding to Yank's statement that speed in the bass range is impossible to estimate. To which I suggested that he select any frequency in the bass range and try to simulate the change in rhythm by turning it on and off. I even gave him a link.
 
Yank said:
If a speaker is capable of reproducing 250-320Hz, then it is certainly "fast" enough to play anything lower than that.

Can you still hear your supposed "speed" in a woofer if you kill everything above 320Hz? If you compare two woofers can you tell which one is faster, if you listen to them through a 320Hz low-pass filter?
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The speed of the bass driver depends on its characteristics, on the volume of the box in which it operates, and on the filter. All of these parameters are equally important. A heavy diffuser will always move slower than a light one with the same power. The speed is also affected by the magnetic system of the driver, the coil and many other things. The volume of the box and the presence of a phase-inverter also affects the speed of the driver. And you can even change the speed of the same driver just by changing the size of the box and the diameter of the phase-inverter. It's all basic speaker design knowledge.
 
Peter_Tos said:
And you can even change the speed of the same driver just by changing the size of the box and the diameter of the phase-inverter. It's all basic speaker design knowledge.
Click to expand...

What's a phase inverter? Do you mean a port?

FWIW I think there are two important requirents for bass to sound right:
1) Lack of the effect shown in Fig 22 here:
https://assets.kef.com/pdf_doc/REF/REF-White-Paper-201219-LR.pdf
and
2) Correct time alignment of the fundamental with the overtones

Note the delay and amplitude reduction of the initial transient in Fig 22, the delay (out of phase with harmonics) of the entire output waveform and the continued output after the input has stopped. Thes effect of this is audible and is why nearly all ported speakers sound a bit (or a lot) wrong in the bass.
And so as not to upset the OT police, the LS5/9 is a ported speaker.
 
S-Man said:
What's a phase inverter? Do you mean a port?

FWIW I think there are two important requirents for bass to sound right:
1) Lack of the effect shown in Fig 22 here:
https://assets.kef.com/pdf_doc/REF/REF-White-Paper-201219-LR.pdf
and
2) Correct time alignment of the fundamental with the overtones

Note the delay and amplitude reduction of the initial transient in Fig 22, the delay (out of phase with harmonics) of the entire output waveform and the continued output after the input has stopped. Thes effect of this is audible and is why nearly all ported speakers sound a bit (or a lot) wrong in the bass.
And so as not to upset the OT police, the LS5/9 is a ported speaker.
Click to expand...
"nearly all ported speakers sound a bit (or a lot) wrong in the bass."

hahaha

this generalisation is truly anti-science
 
Ayya Khema said:
hahaha
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Am I correct in assuming that this a puerile attempt to show that you disagree with me?

Ayya Khema said:
"nearly all ported speakers sound a bit (or a lot) wrong in the bass."

hahaha

this generalisation is truly anti-science
Click to expand...

I suggest you read section 4.2 of the KEF paper I linked above, for the science. The audible effect of this science is alluded to in the following paragraphs:


For many listeners the ported version will be much
more favourable than the closed due to the additional
bass extension, however, the additional bass extension
is not without compromise. With the addition of
the port to the low frequency system, the system
order has been increased and as a result the transient
response is worsened. For example Figures 17 and 18
show the response of the closed and ported systems
to a low frequency toneburst input, the difference
in the temporal response is quite clearly seen. This
creates something of a dilemma as, depending on their
personal preference and room characteristics and
loudspeaker position, some listeners will prefer the
ported response while others will prefer the closed
box response.

For The Reference, as a solution to this issue, the main
loudspeakers are supplied with two different length
port liners. The shorter of the two liners results in
a loudspeaker response similar to that shown in the
ported system above. Fitting the longer liner results
in a frequency response similar to that shown in
Figure 19, the same closed box response is shown for
easy comparison with Figure 16. This low frequency
alignment is specifically designed to roll off very slowly
and gently in the upper bass octaves. In many listening
rooms this will compensate for the natural bass
augmentation due to the closest room boundaries .
 
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S-Man said:
Am I correct in assuming that this a puerile attempt to show that you disagree with me?

I suggest you read section 4.2 of the KEF paper I linked above, for the science. The audible effect of this science is alluded to in the following paragraphs:

For many listeners the ported version will be much
more favourable than the closed due to the additional
bass extension, however, the additional bass extension
is not without compromise. With the addition of
the port to the low frequency system, the system
order has been increased and as a result the transient
response is worsened. For example Figures 17 and 18
show the response of the closed and ported systems
to a low frequency toneburst input, the difference
in the temporal response is quite clearly seen. This
creates something of a dilemma as, depending on their
personal preference and room characteristics and
loudspeaker position, some listeners will prefer the
ported response while others will prefer the closed
box response.

For The Reference, as a solution to this issue, the main
loudspeakers are supplied with two different length
port liners. The shorter of the two liners results in
a loudspeaker response similar to that shown in the
ported system above. Fitting the longer liner results
in a frequency response similar to that shown in
Figure 19, the same closed box response is shown for
easy comparison with Figure 16. This low frequency
alignment is specifically designed to roll off very slowly
and gently in the upper bass octaves. In many listening
rooms this will compensate for the natural bass
augmentation due to the closest room boundaries .
Click to expand...

Kef paper is extremely limited in research. They both use a 15L ported and 15L sealed enclosure, with the same driver. BR normally need twice the cab size then that of a sealed enclosure. I read Kef paper more like marketing rather then a trustable reference.


And when we factor in the audibility or rather relative lack of group delay audibility in the bass range... Then we must also add SBIR factors and room acoustics (the room rings in the bass much more audibly then the GD audibility. Then we must also take into account that Sealed bass will give more distortion vs Ported. and that a properly tuned BR normally need twice the cab size of the sealed enclosure...


"nearly all ported speakers sound a bit (or a lot) wrong in the bass."
ATC, JBL and many major speakers designer continue to use BR enclosure.

I personally have never heard a 10" or even a 12" sound remotely as convincing as a 15" woofer. Ill take a 15" bass in BR enclosure over anything KEF is selling
 
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S-Man said:
I would not be happy with the bass performance of these speakers, along with the vast majority of "hi-end" speakers I heard at the Munich show.
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you would not be happy with the bass of the big atc scm150?
why? because its ported? or because your a proponent of multiple subs smoothing out room modes?
 
(Ironie on) Wow! Nearly 70! off topic post. I bet you will make it up to 100. I'm proud of you. (Ironie off).:rolleyes:
 
Ayya Khema said:
you would not be happy with the bass of the big atc scm150?
why? because its ported? or because your a proponent of multiple subs smoothing out room modes?
Click to expand...

I've never heard the 150s. The 50s have unsatisfactory bass IME, which is a shame because the mid and treble is excellent.
The reason is that the bass sounds blurred to me.
I am not a fan of multiple subs, when I tried Toole's recommendations on siting subs I was not happy with the results. The time domain performance is more important than frequency domain IME/O.

Old Shatterhand said:
(Ironie on) Wow! Nearly 70! off topic post. I bet you will make it up to 100. I'm proud of you. (Ironie off).:rolleyes:
Click to expand...

Is it unreasonable to discuss side issues after the main topic has run its course?
 
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