Hi Andrew, yes I also thought the 45L response curve looked nice, the tradeoff for the low tuning (and smaller box size) is the lower and bigger port resonance. Could reduce port size, but then chuffing might be an issue.
Crossed over around 200Hz it may not be an issue.
I've attached the Closed box step response as well for completeness. edit: and I've redone the 45L one with port resonance disabled just for comparison of the step response between the low Q sealed and the vented.
Andrew I've just often seen Q of 0.5 touted as a personal preference, I'd have to check what the Q of my sealed speakers are. I think probably around 0.7
*more on topic bit* My bass reflex cabinets whilst they play low are quite boomy (They were repurposed cabinets and I was pretty naive when I designed the new tuning). Their step response in moddeling is not great.
My MTM's are sealed dual 5" drivers. I definitely prefer the sound of the bass from them, but they were never intended to play low. The do a surprisingly good job though (with F3 around 80Hz).
I will likely build new cabinets for my 10" woofers and plan to go with a response more like the 45L modeled response above. I'm hoping that I won't be disapointed. I may choose a volume that would also possibly be suitable for sealed.
Tinitus, I've never build a large driver sealed speaker. The response when I see it seems it would be lacking in bass... is the reality different?
Tony.
Crossed over around 200Hz it may not be an issue.
I've attached the Closed box step response as well for completeness. edit: and I've redone the 45L one with port resonance disabled just for comparison of the step response between the low Q sealed and the vented.
Andrew I've just often seen Q of 0.5 touted as a personal preference, I'd have to check what the Q of my sealed speakers are. I think probably around 0.7
*more on topic bit* My bass reflex cabinets whilst they play low are quite boomy (They were repurposed cabinets and I was pretty naive when I designed the new tuning). Their step response in moddeling is not great.
My MTM's are sealed dual 5" drivers. I definitely prefer the sound of the bass from them, but they were never intended to play low. The do a surprisingly good job though (with F3 around 80Hz).
I will likely build new cabinets for my 10" woofers and plan to go with a response more like the 45L modeled response above. I'm hoping that I won't be disapointed. I may choose a volume that would also possibly be suitable for sealed.
Tinitus, I've never build a large driver sealed speaker. The response when I see it seems it would be lacking in bass... is the reality different?
Tony.
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the closed shown clearly goes deeper than the two vented 😉
and maybe with better phase behaviour
the vented ones might have more phase anomalies
which could lead to bass not being perceived exactly like what it looks on paper
may be the closed also would be better with Qtc 0.55 (or so)
and then there is the room gain aspect
of the two vented shown, I would prefer the one with more rounded gradual rolloff
Do the modeling again with different port tuning and a slightly larger cabinet. Poor design aside The boomy bass from your BR cabinet could be due to room localization and poor damping from your amplifier. Listen to the speaker outside in free space , if the bass is no longer "boomy " then room setup is the issue.
Measured responses of both sealed vs BR of the speakers you are comparing would tell us more, T/S parameters don't tell you everything , sometimes larger works better than sims suggest, port ratios are very important.
Measured responses of both sealed vs BR of the speakers you are comparing would tell us more, T/S parameters don't tell you everything , sometimes larger works better than sims suggest, port ratios are very important.
I would go for higher Q with small drivers in a closed box. I.e. if your lower cutoff frequency is higher than about 50 Hz it is better to have a Qtc around 0.7 than 0.5 because the latter might sound anemic. Transient-response is not the only subjective parameter playing a role here.
My favourite tuning for home listening is also closed box with a Qtc between 0.5 and 0.6 but then - 6 dB (i.e. tuning frequency) should be around 30 Hz.
There are situations however where vented is OK for me like live-sound for instance.
Regards
Charles
My favourite tuning for home listening is also closed box with a Qtc between 0.5 and 0.6 but then - 6 dB (i.e. tuning frequency) should be around 30 Hz.
There are situations however where vented is OK for me like live-sound for instance.
Regards
Charles
perfect, less boom boom
anyway, measured 'in room' may look very different
but I actually focus more at where the -12db point is 😉
that would be perfect
and if I remember correctly, another 12" SB34NRX75-6 should be able to manage that
I like this.
the step response of the vented 64L, vented 45L and sealed 64L are now modeled and available for comparison.
The closest to Butterworth has 3 ripples after the step, the near Bessel has two ripples and the vented has one ripple.
I think you would be able hear these differences.
I have not (knowingly) listened to big sealed speakers so I can only guess at the audibility of the different Q values by comparing to the different vented alignments.
In vented the different alignments are very audible.
I hate one note bass or bass boom and these come when Q exceeds 0.7
For me that is a no go area in vented.
Sealed often end up in the Q>0.7 and have little low bass response.
Not an area I want to experiment in.
Whereas with Mid-band reproducers the Sealed Butterworth roll off combined with an active filter will give a very precise "shape" when used in a crossover.
the step response of the vented 64L, vented 45L and sealed 64L are now modeled and available for comparison.
The closest to Butterworth has 3 ripples after the step, the near Bessel has two ripples and the vented has one ripple.
I think you would be able hear these differences.
I have not (knowingly) listened to big sealed speakers so I can only guess at the audibility of the different Q values by comparing to the different vented alignments.
In vented the different alignments are very audible.
I hate one note bass or bass boom and these come when Q exceeds 0.7
For me that is a no go area in vented.
Sealed often end up in the Q>0.7 and have little low bass response.
Not an area I want to experiment in.
Whereas with Mid-band reproducers the Sealed Butterworth roll off combined with an active filter will give a very precise "shape" when used in a crossover.
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Room could definitely be a big part of the problem... I remember back when the vented boxes used to be used at parties they always sounded much better outside. My current room has a large peak at around 40- 50Hz. The MTM's (sealed) should be down about 12db at 40Hz and the in room response has a peak there!
I've thought about a sealed box with a linkwitz transform as well, but think that the efficiency would be too low...
I guess in the end I'm just going to have to build some prototypes and see what works best 🙂
Tony.
I've thought about a sealed box with a linkwitz transform as well, but think that the efficiency would be too low...
I guess in the end I'm just going to have to build some prototypes and see what works best 🙂
Tony.
It is my view that sealed AND Linkwitz transform is the only way to get extended low bass response.
As I said a little earlier it's not a route I will be following.
Even further back I said
He can always eq down the BR to match room acoustics or better , invest in bass traps and room tunes.....
Just saying ......
Just saying ......
higher Qts is very audible
yeah, modern digtal EQ is ofcourse another option to consider
would be interesting to see if it might end up looking like the sealed
digital EQ seems very commonly used with vented bass
I suppose less so with closed
oh, btw, if anyone here with monster subs also frequently gets tired with headackes, I may be able to tell you why
better turn down the SPL when doing very long listening sessions
Hello, just for fun look at this ... unbelievable ...
B&W ASW600 - YouTube
what is the sense to get a bass that has this low level of control i do not understand
And this is a sub ! a unit dedicated to reproduce only bass !
But is this normal ??? is this acceptable ?
I cannot even image the level of distortion ... if this is a perfect piston i am a piston myself as well !
Regards,
gino
B&W ASW600 - YouTube
what is the sense to get a bass that has this low level of control i do not understand
And this is a sub ! a unit dedicated to reproduce only bass !
But is this normal ??? is this acceptable ?
I cannot even image the level of distortion ... if this is a perfect piston i am a piston myself as well !
Regards,
gino
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It's true, I've noticed that YouTube videos do not necessarily live up to high standards of sound reproduction.
Hehe ... joke aside ... i have read that, roughly speaking, the more the excursion of the cone the more the distortion
And of course if some kind of excursion must be the cone should be perfectly undeformed and vertical, like a real piston.
Are these generic statements acceptable ?
In this view also a video recording can say a lot ... as in this case
But seriously ... how it is possible this kind of behavior ? never seen something like this ...
Thanks a lot and kind regards,
gino
And of course if some kind of excursion must be the cone should be perfectly undeformed and vertical, like a real piston.
Are these generic statements acceptable ?
In this view also a video recording can say a lot ... as in this case
But seriously ... how it is possible this kind of behavior ? never seen something like this ...
Thanks a lot and kind regards,
gino
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