Subwoofers: Ported or sealed?

@phusis - I am currently crossing them over at around 180Hz. My main speakers are dipole line arrays which start to roll off around 200Hz, so this crossover point blends well. The sub towers with the plate amps I'm using won't play much higher than this. 

The drivers are made by Rythmik for GR-Research,  using a paper cone specifically optimized for open baffle. Each tower is driven with a Rythmik plate amp (HX800) which is built using two Hypex 400w amps, so the plate amp actually has two channels of output, each of which is connected to two drivers. These drivers have a second voice coil which is used as a servo feedback circuit to the amps. 

I don't think I've heard a tapped horn sub, but from your description I suspect the OB subs sound somewhat similar. They don't pressurize the room like a conventional sub - the bass is there in the room. For music from traditional instruments like double bass or kick drums, this sounds very natural. These instruments don't pressurize the room either. 

But if you are looking for that kick-in-the-chest sound, this type of sub is probably not for you. I wouldn't use them for home theater, for example, since most of the bass is from sound effects like explosions which you do want to pressurize the room. 

@jaytor --

It would be interesting to experiment with a pair of open baffle subs in a 2nd listening space and setup - they seem like a very capable design, not least as an overkill i.e.: über-sized option. 180Hz low-pass should be plenty enough to allow for a variety of design options above, like Danley’s Synergy horns or, like in your case, a line source.

Come to think it I listened to a pair of Quad ESL 63’s augmented I believe with a pair of open baffle fitted-to-the-Quad’s Gradient subs (dual 12" Peerless woofer per cab) back in the 90’s, and it was the best I ever heard the Quad’s. Indeed the pairing with the Gradient OB subs was excellent, and going by memory I’d favor that combo over the newer, more full range Quad iterations.

The TH’s are great for both music and movies, so yes, perhaps an OB solution wouldn’t offer the same versatile abilities here. Nonetheless they sound like an intriguing option.

@jaytor wrote: "[Open baffle subs] don’t pressurize the room like a conventional sub - the bass is there in the room. For music from traditional instruments like double bass or kick drums, this sounds very natural. These instruments don’t pressurize the room either.

"But if you are looking for that kick-in-the-chest sound, this type of sub is probably not for you."

Imo the advantage of an open-baffle, dipole sub is better room-interaction than monopole (omnidirectional) subs, resulting in smoother in-room bass. And smooth bass is "fast" bass, perceptually, because it is the in-room peaks which take longer to decay into inaudibility and therefore muddy up the bass. The result includes superb pitch definition in the bass region. But one trade-off is, good dipole bass doesn’t kick you in the chest like good monopole bass does. I say this as a long-time dealer for dipole speakers (SoundLabs).

Imo there is a technique which can combine in-room bass smoothness with kick-in-the-chest sound, and that is to use multiple monopole subs intelligently distributed. As the number of distributed bass sources increases, the in-room frequency response smoothness increases, and the variation in that frequency response from one location to another within the room decreases.

Disclaimer: I manufacture a distributed multisub system, BUT the concept can be implemented just by using multiple subs and spreading them around the room, and the subs do not have to match.

Imo the room’s effects in the bass region are roughly an order of magnitude more significant than the differences between comparably high-quality subs, so arguably HOW MANY subs you use (and how you use them) can matter more than WHICH sub(s) you use.

Duke

Or just get a monster sealed sub like the SVS PB-16 that can get low while sealed.  1500 watts and have the best of both.  Or preferably two.

I follow the “there is no replacement for displacement” philosophy for subs.

This much talk about subwoofers can’t help me wonder about how many folks out there are using them correctly. Fortunately there is software to help configure them properly… but, I am surprised how often I have found folks with them turned up way too loud and with the cross overs way too high… doing more damage to the sound than good.

Recently, I was over a friend’s house comparing some components. He put on an electronic album with lots of bass… I couldn’t tell anything about the components. I asked about the settings on the subwoofer. It was set to something like 60% volume and a crossover 120 hertz. His speakers were flat to 40hz.

So I had him adjust it while I listened. We ended up with a crossover of 35hz and 20% volume. So both knobs were really close to zero. He was shocked how much better it sounded… the bass wasn’t obscuring the other instruments, the sound field opened up. We listened to the electronic tune… massive single bass notes turned into many… a whole different thing.

Home theater is completely different… you want to rattle your windows. But for 2 channel audio it is really easy to do more damage than good and detailed discussions about sub woofer output bring up concerns of over use of subs.

I currently have no subs in my main system, while there are two B&W 800 series subs in our home theater. While I consider putting a couple (Sonus Faber) subs into my system… I am enjoying the complete coherence across the audio spectrum. True, they only go to 28hz… but they sound fantastic.