Subwoofer terms described

[5thgenaccord 10+ year member]

I was wondering what these terms mean and if it is better to have a higher number or lower number.

Sensitivity and frequency response

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[Chevyaudio 5,000+ posts]

understanding only 1 or 2 T/S parameters is not going to help you. You need to learn them all, Study them, and know what each one means. That will help you a ton when picking out drivers, and the enclosures that will suit them best. This has been discussed many times around here, just do a little searching.

 

[newusername 10+ year member]

I would pay little-to-no attention to a sensitivity or efficiency rating provided for any subwoofer. There are too many measurement artefacts and inconsistencies to compare one to the other.

The same goes for a published frequency response. For example, a company may publish Frequency Response ranging from 18-200hz, but in what situation does that occur? Knowing that the enclosure has the greatest control on response shape for a subwoofer, you must wonder why they would claim something like that. If they do make that claim, then you must question if that's F3, F6, F10, etc?

The two that you listed there will tell you virtually nothing at all about anything, although one could argue that a low sensitivity/efficiency is better for a driver to be used in a subwoofer.

When it comes to the remaining important parameters (Qms, Qes, Vas, etc), you must understand how all interact with each other. Furthermore, it is important to understand that ALL theile/small parameters are derived from 5 other metrics:

Re

BL

Cms

Mms

Sd

Of those 5, three are of a dynamic nature and change when power is applied, so it is also important to understand how they change and what these changes cause.

I don't think an understanding of theile/small parameters can be taught (and have you come away understanding) in a single thread, so if you're interested in learning more, start reading around. Of course, I can go into more detail if you're really interested, but much of it has already been discussed in fairly adequate depth.

Neil

 

[5thgenaccord 10+ year member]

I would pay little-to-no attention to a sensitivity or efficiency rating provided for any subwoofer. There are too many measurement artefacts and inconsistencies to compare one to the other.
The same goes for a published frequency response. For example, a company may publish Frequency Response ranging from 18-200hz, but in what situation does that occur? Knowing that the enclosure has the greatest control on response shape for a subwoofer, you must wonder why they would claim something like that. If they do make that claim, then you must question if that's F3, F6, F10, etc?

The two that you listed there will tell you virtually nothing at all about anything, although one could argue that a low sensitivity/efficiency is better for a driver to be used in a subwoofer.

When it comes to the remaining important parameters (Qms, Qes, Vas, etc), you must understand how all interact with each other. Furthermore, it is important to understand that ALL theile/small parameters are derived from 5 other metrics:

Re

BL

Cms

Mms

Sd

Of those 5, three change are of a dynamic nature and change when power is applied, so it is also important to understand how they change and what these changes cause.

I don't think an understanding of theile/small parameters can be taught (and have you come away understanding) in a single thread, so if you're interested in learning more, start reading around. Of course, I can go into more detail if you're really interested, but much of it has already been discussed in fairly adequate depth.

Neil

Thanks