Ported will have more punch for movies and will sound bigger but most ported subs I have heard lose a bit of detail for music. To get the same performance out of a sealed sub, you need to dramatically increase the power output and a sealed sub will deliver the same big punchy sound of its ported counterpart. The unfortunate part is that usually means a step up in price.

I am not familiar with Rythmik or SVS and can offer no advice on them. I would offer two suggestions of ones I am familiar with -

NHT B-10d. It is $599, sealed but it's 300w amp in a small room should deliver big sound from a home theatre perspective and NHTs subs are very musical. Check out the website for NHThifi.

Wharfeldale Diamond 10.GX. This is an $800 sub that is currently available from MusicDirect for $599. They have two Demos and a photo shoot item available. 250w of power, goes down to 30hz and delivers a clean musical sound.

I like the NHT for music & movies, I like Wharfeldale better for music than movies. Both are darn nice sounding subs for the money.

I have the NHT B12D sub and it is a sealed design and is excellent.

The ported subs invariably have resonances at certain frequencies that are poorly damped, so when something is at that frequency it is going to be "boomy". They just don't have a very linear response.

The B12D is $800, but the B10D would be enough for most situations and is $600.

The sealed subs do need more power, but NHT has taken care of that; their subs come with the power they need.

Some good advise on subs here already.

Sealed can have some advantages over ported for music.
On a budget SVS & HSU provide good bang for the dollar.
Rythmic is another that offers good value, especially if you can get the kit & assemble it yourself.

What ever route you, new, used ported or sealed………
I would recommend you consider using two subs, especially for music.

Placement is a critical issue when implementing a sub. Especially when you are trying to maintain a smooth, level, integrated & natural frequency response required for good music reproduction.
Implementing two subs will help tame room modes that are created by low frequency signals.
This will allow greater flexibility in placement & better, more even overall response throughout the room.

You can use an inexpensive Radio Shack decibel meter when tuning your sub to provide a sooth, even integration to your main speakers. There are probably a lot phone apps too, but not all of them are always as accurate as you will want.

JMHO, YMMV

Bill - on the Hill
Practicing Curmudgeon & Audio Snob
- just an “ON” switch, Please –

I think you will pleased.

Bill - on the Hill
Practicing Curmudgeon & Audio Snob
- just an “ON” switch, Please –