Hello world!! I'm a complete newbie to loudspeaker design. I just want to ask, if you put a woofer meant for ported application into a sealed enclosure or vice-versa what would happen with regards to sound quality,efficiency e.t.c. Thank you so much.
The primary (but not the only) parameter that differentiates a "sealed box" woofer from a "vented box" woofer is the Qts of the driver.
A very low Qts indicates the driver will perform better in a vented box. Qts < 0.3
A very high Qts indicates the driver will perform better in a sealed box. Qts > 0.45
The range of Qts between 0.3 and 0.45 is actually where most drivers live. These drivers can be made to work with either sealed or vented box. You must do a simulation to determine which alignment most meets your needs.
So for woofers in the middle range, they are not meant for either ported or sealed, they are meant to be used in both.
It is more complicated than this simplistic explanation, but this gives you some ideas to chew on...
A very low Qts indicates the driver will perform better in a vented box. Qts < 0.3
A very high Qts indicates the driver will perform better in a sealed box. Qts > 0.45
The range of Qts between 0.3 and 0.45 is actually where most drivers live. These drivers can be made to work with either sealed or vented box. You must do a simulation to determine which alignment most meets your needs.
So for woofers in the middle range, they are not meant for either ported or sealed, they are meant to be used in both.
It is more complicated than this simplistic explanation, but this gives you some ideas to chew on...
The resulting sound quality would most likely suffer:
Efficiency Bandwidth Product (EBP)
Efficiency Bandwidth Product (EBP) is a number which shows the trade-off between efficiency and bandwidth of a driver. It is useful in determining if a driver is suited for a sealed or vented box and is also used to determine suitability for horn loading.
EBP = fs / Qes
As a general rule:
EBP < 50 - use only for a sealed box
EBP 50 - 100 - can be used in either
EBP > 100 - vented box only
Red Spade Audio: Efficiency Bandwidth Product (EBP)
Perhaps a simpler is better approach might be in order.
If it's meant for ported and you put it in a sealed box, the bass will be underwhelming.
If it's meant for sealed and put in a ported enclosure it will sound boomy.
If it's meant for ported and you put it in a sealed box, the bass will be underwhelming.
If it's meant for sealed and put in a ported enclosure it will sound boomy.
I've actually been wondering about this question lately in terms of suspension stiffness.
So if generally a driver intended for a vented alignment has a stiffer suspension, how is sound quality affected by putting it in a sealed box and thereby having the air spring increase the stiffness even further? Would it be less 'open'? Less dynamic?
In particular I'm thinking of those occasions in a 3-way where a low Qts 5" or 6.5" driver is used as the mid in a sealed box. And I'm wondering if in this type of application if a lower Q sealed alignment or perhaps even better an aperiodic alignment would be the better choice. Is this perhaps the reason or part of the reason Troels uses aperiodic in so many of his 3+-way speakers?
So if generally a driver intended for a vented alignment has a stiffer suspension, how is sound quality affected by putting it in a sealed box and thereby having the air spring increase the stiffness even further? Would it be less 'open'? Less dynamic?
In particular I'm thinking of those occasions in a 3-way where a low Qts 5" or 6.5" driver is used as the mid in a sealed box. And I'm wondering if in this type of application if a lower Q sealed alignment or perhaps even better an aperiodic alignment would be the better choice. Is this perhaps the reason or part of the reason Troels uses aperiodic in so many of his 3+-way speakers?
you will also struggle on specific alignments. in closed: butterworth, bessel,linkwitz
in vented, SBB4, QB3 and C4
it can happen that you say:
i want a critical damped alignment in a sealed enclosure für maximum transient response.
you take a woofer build for vented boxes and end up in a 250 liter sealed enclosure for a 6" woofer....😀
in vented, SBB4, QB3 and C4
it can happen that you say:
i want a critical damped alignment in a sealed enclosure für maximum transient response.
you take a woofer build for vented boxes and end up in a 250 liter sealed enclosure for a 6" woofer....😀