That's still wrong. Put a driver into a TML etc, it can be flat as it wants to be, the run time of the distance of the sound is always part of the time it needs the signal to go through the system. Which, as you know, it is definition of group delay. So the length (=time) of the distance will automatically increase the gd.
That means,
a. the box type does matter
b. no matter what magnitude the frequency response is, GD still applies
Or, in other words, the statement is completely wrong. Period.
If they are in the same sealed enclosure. In the same ported, the lower Qts driver have a higher group delay peak around Fb.
C'mon, you really know what I mean.
Corner-case constructions aside, a single speaker in any type of enclosure is a minimum-phase system. It takes quite some effort to create a speaker that has singificant excess phase. For, say, a quarter wavelength of excess delay at 30Hz the sound from the TML exit has to take a 2.5m long detour to the listener.
Closed and ported speakers can safely be considered minimum phase.
And from that it follows that group delay is directly connected to SPL magnitude alone, and no matter how that magnitude was created, ported or sealed, EQ'd (like Linkwitz-transformed etc) or not. Relevant is the response of the overal acoustic system highpass function.
The same result for ported as well. If the two drivers are identical in every spec other than BL (which will raise the Qts without affecting the other parameters), and they are put in the same enclosure airspace with the same port tuning, the higher Qts driver will still have more group delay even at port tuning.
No.
Here is the same driver, enclosure and tuning but with a Bl = 17 (Qts = 0,38) and a Bl = 24 (Qts = 0,19):
Bl = 17 (Qts = 0,38):
Bl = 24 (Qts = 0,19)
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I did and you are right.
But then again, fot flat alignment of those two speakers the tuning should be different (higher for low q driver), leading to lower group delay of a low q driver system.
That's not an apples to apples comparision. You need need to EQ them to the same target response and then GD is exactly the same.
But who cares flat tuning since we have EQ? Ported speakers should be tuned to how low you want to go, because below port tuning the speaker start to get unusable.
Anyway, @hurrication claimed same enclosure (Vb) and tuning (Fb).
Anyway, @hurrication claimed same enclosure (Vb) and tuning (Fb).
Of course after EQ-ed to the same frequency response they would be the same but that was not the question of @hurrication. He mentioned same box, same tuning (no EQ was mentioned) and he stated the higher Qts driver will have a higher GD at Fb.
With Bl = 17:
Re 5,20 Ohm Qms= 14,09
Le 1,15 mH Qes= 0,39
0,00001 Qts= 0,38
0,00001
0,00001 SPL (max)= 95,24 dB/2.83V/m
Bl 17,00 Tm Mmr (4pi no baffle)= 14,36 g
Mms 105,0 g Mmr (in box)= 21,00 g
Rms 1,55 Ns/m Vas= 228,3 liter
Cms 0,22 mm/N fs = 33,11 Hz
1,00E-06 Rams = 2,89E-07 Ohm*s
d 330 mm Sd = 855,30 cm2
Box
vented
Vb1 155,0 liter Fill matrl: Polyester fill (PET) *note
Filling 15% Fill amount: 83,7 gram
QL 7 Eff.Volume VB' = 161,1 liter
fP 26 Hz Total Q = 0,61 (in closed box)
QP 100 fsbox= 51,49 Hz (in closed box)
#vents 2 pcs. Baffle Step: Baffle Width = 42 cm
diam. 84 mm Calculated Port length = 216 mm
With Bl = 24:
Re 5,20 Ohm Qms= 14,09
Le 1,15 mH Qes= 0,20
0,00001 Qts= 0,19
0,00001
0,00001 SPL (max)= 98,59 dB/2.83V/m
Bl 24,00 Tm Mmr (4pi no baffle)= 14,36 g
Mms 105,0 g Mmr (in box)= 21,00 g
Rms 1,55 Ns/m Vas= 228,3 liter
Cms 0,22 mm/N fs = 33,11 Hz
1,00E-06 Rams = 5,76E-07 Ohm*s
d 330 mm Sd = 855,30 cm2
Box
vented
Vb1 155,0 liter Fill matrl: Polyester fill (PET) *note
Filling 15% Fill amount: 83,7 gram
QL 7 Eff.Volume VB' = 161,1 liter
fP 26 Hz Total Q = 0,31 (in closed box)
QP 100 fsbox= 51,49 Hz (in closed box)
#vents 2 pcs. Baffle Step: Baffle Width = 42 cm
diam. 84 mm Calculated Port length = 216 mm
Re 5,20 Ohm Qms= 14,09
Le 1,15 mH Qes= 0,39
0,00001 Qts= 0,38
0,00001
0,00001 SPL (max)= 95,24 dB/2.83V/m
Bl 17,00 Tm Mmr (4pi no baffle)= 14,36 g
Mms 105,0 g Mmr (in box)= 21,00 g
Rms 1,55 Ns/m Vas= 228,3 liter
Cms 0,22 mm/N fs = 33,11 Hz
1,00E-06 Rams = 2,89E-07 Ohm*s
d 330 mm Sd = 855,30 cm2
Box
vented
Vb1 155,0 liter Fill matrl: Polyester fill (PET) *note
Filling 15% Fill amount: 83,7 gram
QL 7 Eff.Volume VB' = 161,1 liter
fP 26 Hz Total Q = 0,61 (in closed box)
QP 100 fsbox= 51,49 Hz (in closed box)
#vents 2 pcs. Baffle Step: Baffle Width = 42 cm
diam. 84 mm Calculated Port length = 216 mm
With Bl = 24:
Re 5,20 Ohm Qms= 14,09
Le 1,15 mH Qes= 0,20
0,00001 Qts= 0,19
0,00001
0,00001 SPL (max)= 98,59 dB/2.83V/m
Bl 24,00 Tm Mmr (4pi no baffle)= 14,36 g
Mms 105,0 g Mmr (in box)= 21,00 g
Rms 1,55 Ns/m Vas= 228,3 liter
Cms 0,22 mm/N fs = 33,11 Hz
1,00E-06 Rams = 5,76E-07 Ohm*s
d 330 mm Sd = 855,30 cm2
Box
vented
Vb1 155,0 liter Fill matrl: Polyester fill (PET) *note
Filling 15% Fill amount: 83,7 gram
QL 7 Eff.Volume VB' = 161,1 liter
fP 26 Hz Total Q = 0,31 (in closed box)
QP 100 fsbox= 51,49 Hz (in closed box)
#vents 2 pcs. Baffle Step: Baffle Width = 42 cm
diam. 84 mm Calculated Port length = 216 mm
Well, those TSP aren't possible, that's what I suspected. Editing one parameter without the other interacting ones is very convenient for any theory but, unfortunately, doesn't provide any proof for said theory.
Yeah, sure. My VW bug drives scribble in the technical data so much faster than the Porsche! See? shows scribbled 2500hp