Subwoofers - does size matter ?

[amackie]

Can anyone explain what effect the size of the enclosure has for a subwoofer ? As a bit of a newbie to subs, I'm wondering whether "size really does matter".

Can compact subs such as an MJ Acoustic Reference 100 or REL Quake sound as good as a sub with a larger enclosure that uses the same size of driver ? Do sealed enclosures allow smaller sizes than enclosures with a port ?

I can understand why a larger driver would make a difference, as it can move more air, but why would a larger enclosure make a difference ?

Thanks!

[Ian J]

Secrets of Home Theater published a review of several subs here which includes a brief explanation of why biggest is best and links to further articles on subwoofer design.

Compact subs like the two that you mentioned will never have the depth and power of larger enclosures but they are by their very design, a compromise

[Posh Bloke]

For a sealed non ported sub, making the box smaller raises the resonance of the driver and therefore the sub's low freq cut off point. To overcome this the manufacturer needs to apply a steeper LF gain profile and therefore a much more powerful amp to cope with this extra low freq gain (and a higher power and specified driver).
To see evidence of this look at the relative sizes of the REL Strata III and Q200 subs. Both sealed but the Strata has a significantly larger box. This means it can use a 100W amp instead of the 400W of the Q200 and still have better responce and max output.
Once moving to a ported sub then the manufacturer can no longer use aggresive eq profiles as the driver has no sealed air behind it to stop it from moving too far. These rely on good old physics to calculate the port size, length and cabinet size for the driver in use.

[Respectamonkeee]

there are small subs that do bass well....just look at the velodyne SPL 1000 or 1200 both go very low with great volume and minimal distortion and have decent and large amps 750w...The version 2 is also out now with a 1000w rms amp peaking at 2000w


SPL mk 1 can be had for very good prices atm

[amackie]

I'm thinking primarily for home cinema, in a 14'x12' room. I'm not really after "room-shaking" bass, rather I just want to make sure I'm not missing out on all the info in the LFE channel. I'm thinking the sub should "disappear" and blend in with my other speakers (which start dropping off between 50-60Hz). Constraints such as neighbours, wife, and no wardrobe sized-box mean the MJ Acoustics subs seem ideal size-wise, I'm just wondering if they really are suitable for producing good quality bass in a 5.1 setup.

[Ian J]

Originally posted by amackie
Constraints such as neighbours, wife, and no wardrobe sized-box mean the MJ Acoustics subs seem ideal size-wise, I'm just wondering if they really are suitable for producing good quality bass in a 5.1 setup.

They are absolutely ideal which is why they have been given five stars by every mag that has tested them and also why they have sold so many.

There is much posted about how deep and loud some subwoofers go but most of them are totally unsuitable for anyone that doesn't live in a double glazed detached house.