Are sealed subs the most musical?

Originally Posted by PaulF

I am trying to figure out what pair of subs to mate with a pair of B&W 802s. The system would be used 50/50 for music and HT. Music performance is important, even if I have to give up a couple of dB of output. Sealed subs are said to be tighter, better group delay etc.

This guy seems to really prefer sealed subs and is particularly fond of the Vandersteen 2Wq >> audioperfectionist

I am considering the JL F113. However, when I compare the distortion results to other non-sealed subs it comes out the highest.

-SVS PB-13 Ultra, ported, 6% THD at 20Hz and 100dB >> PB-13 Ultra
-Earthquake Supernova MKVI, passive radiator, ~6% THD at 20Hz and 100dB >> Earthquake Supernova MKVI
-JL F113, sealed, ~12% THD at 20Hz and 100dB >> JL F113

Yet at the same time most dealers slanted towards audio in my area claim the REL Brittannia mate better with front speakers for two channel audio. These use a ported transmission line config.

I am interested in any thoughts on sealed vs ported, and in particular how the distortion affects sound. Anyone seen distortion numbers on Paradigm's Sub25?

Originally Posted by thehun

There is very little musical content at 20hz to begin with, and you would be hard-pressed to "hear" even 12% distortion as your main speakers would mask it for sure.

REL advocates speaker level input use, and no high-passing the mains but low passing the sub with it's built in crossover. REL also have some outlandish claims regarding it's low end output, yet I've seen no reliable objective measured data on any of their sub[besides T3 on S&V]. But it's a different matter.

Both sealed and ported subs have some good examples[makes and models] that would fit the "musical" bill.

Originally Posted by PaulF

Thanks for the input guys. I want to avoid a sub that sounds flabby or boomy. While I really like the 802s, their ported design makes them sound tubby when placed within 2-3 feet of a side wall, at least when I heard them. I think a sealed sub may have that tight sound I'm looking for and be less sensitive to room placement.

I just wasn't sure how audible the measured distortion would be. Does the DSP in a sub like the Sub25 help in this regard?

Originally Posted by penngray

all the top subs recommended daily on here are oing to sound tight and perform awesome for music or movies....sealed or ported! "Tight" is not a design consideration.

ZERO subs are LESS sensitive to room placement. You need to properly place any sub you buy to get the best in room response. If you choose not to that is cool but there is no such thing as a sub design that is room indepedant....well almost, A nice monster IB install is kind of room independant

Originally Posted by PaulF

I'm not suggesting in any way that room placement is not important but have to believe that a sub with a passive driver on the opposite face of the main driver, or a down-firing port in addition to the main driver will make the sub a little more difficult to position.

Originally Posted by PaulF

I'm not suggesting in any way that room placement is not important but have to believe that a sub with a passive driver on the opposite face of the main driver, or a down-firing port in addition to the main driver will make the sub a little more difficult to position.

Originally Posted by PaulF

So guys what makes a sub sound musical? Having read tons of material on subs I found there seems to be no consensus.

Some say that crossing over with the mains is the most important aspect, having a great degree of control on the cross-over freq etc. Also taking the main amp's signature for the front into consideration. This is RELs approach. Another company called MJ Acoustics claims to take this to the ultimate level.

Then others like The Audio Perfectionist linked above claim that sealed subs are the best for performance and integration with the main speakers. Talks about first order cross-overs etc.

What characteristics should one look for when seeking out a sub that's musical?

So guys what makes a sub sound musical? Having read tons of material on subs I found there seems to be no consensus.

Originally Posted by mojomike

What you're looking for is accurate in-room performance. That calls for choosing the best sub design for the particular acoustic characteristics of your room. In a small, sealed room, a big ported sub may sound boomy due to a lot of room gain. In that case, a small sealed sub could sound better. On the other hand, in a large and open room, a big ported sub may be what's called for. That bottom line is you are shooting for a flat in-room frequency response and a smooth blending between the sub and the mains.

Originally Posted by cschang

All things being equal, small room, etc.....

Two subs, one ported and one sealed, both flat to 18hz, but typical rolloffs below 18hz, why would the ported sub sound boomy?

Originally Posted by mojomike

A typical decent quality sealed sub with no internal or external bass boost will exhibit a 12db/octave rolloff below 30 to 40hz measured anechoicly while a good ported sub measured under the same conditions might measure flat to 18hz, and then rolloff sharply below that. Put those two subs in a small sealed room, there a good chance that the sealed sub will flatten out to 18hz while the ported sub will sound boomy with no applied eq.

Originally Posted by cschang

That would mean that the -3dB points with a 12dB/octave rolloff beginning at 30hz would not even get to 18hz...correct? Can you give me an example?

What if the two subs, ported and sealed, as I mentioned, were flat to 18hz, or had -3dB points at 18hz?

What quality sealed subs don't have EQ tuning involved?

Originally Posted by mojomike

Why do you say the sub wouldn't get to 18hz? With a -3db point at 30hz and a 12db/octave slope, at 15hz the sub should be 15db lower than at 30hz. It doesn't stop, but it rolls off. Have you seen frequency response charts for the Submersive which is one of the best regarded sealed subs out there?

Originally Posted by rhcorolla

After a fair amount of research seeking a "musical" sub, I ended up w/ a Rythmik Audio F12G 12" servo sub. Danny Ritchie of GR Research supplies the subwoofer in this unit (check out his thread at Audio Circle). He has been involved in many. many speaker / cabinet designs. His comments about these servo subs:

"Comparing these to un-controlled subs is really no comparison. Doing so is like comparing fine articulated bass response to one that goes boom, boom. It's like comparing a Corvette to a Bus."

"these subs will handle music (from a quality stand point) better than any sub on the market. I am not saying that just to sell subs either. I really believe there is nothing better. This technology really is that far ahead of everything else out there."

PS, You might be even more interested since Rythmik Audio is in Austin, Texas....

Originally Posted by penngray

Rythmik, SVS, HSU, Epik, Seaton, Sealed eDs.....put their names in a hat and draw one.....they are all very similar wrt performance and the OP can not go wrong with any of them.

The Rythmik choice is not superior to any other high end choice.

Originally Posted by cschang

Sorry...wrong choice of words. I meant it would not be flat to 18hz.

So if a sealed sub and ported sub both had -3dB points at 18hz, or anywhere else for that matter...why would the ported sub sound boomy?

BTW, Mark has post that there is EQ involved in the Submersive's amp.

Originally Posted by mojomike

If a ported sub and a sealed sub with low boost had the same anechoic -3db response to 18hz, then either one might sound boomy in a small closed room because room gain would cause a rising bottom end with both subs.

Originally Posted by penngray

Rythmik, SVS, HSU, Epik, Seaton, Sealed eDs.....put their names in a hat and draw one.....they are all very similar wrt performance and the OP can not go wrong with any of them.

The Rythmik choice is not superior to any other high end choice.

Originally Posted by PaulF

I am building a new room, approx. 3500 cubic ft. I will have an opportunity to build/wire appropriately for placement and also for in-room acoustics. The room will be sealed, approx 19.5' wide x 19' deep with an opening into part of the rear (1/2 wall high) about 6ft wide plus the corridor to the door. Area behind the opening is about 90-100 sq. ft.