Compact Sealed Subs: Rythimk vs Hsu

[sholling]

I've been doing some preliminary research on compact 15" sealed subs for a 3000cuft room and have become intrigued by two subs: Rythmik's E15 and Hsu's ULS-15. Both are compact sealed subs with 15" drivers.

The Rythmik is a servo design rated at 600w and has a reputation for a very-very tight musical sound but a limited frequency response of 14-80hz although some depute that they will really go that low. They also have a reputation for moderate output compared to other 15" subs. However Brian (the designer) seems confident that it will do fine in 3000cuft.

On the other hand the more conventional 600w (1200w peak) Hsu claims a frequency response of 15-200hz and rates the ULS-15 in spaces up to 4500cuft. At $1100-1300 depending on finish they are both within a few dollars of each other.

Both companies have a reputation for producing "musical" subs for what that's worth. Just based on reputation it looks like finesse vs very refined brute force. I'm 2 hours from Hsu and can make the pilgrimage to give a listen in a few weeks, but I'm too far to go listen to a Rythmik. What I'm looking for is some word on whether the rather cult following of the Rythmik is justified or is the Hsu plenty musical and kick-butt for 50:50 music and movies in a 3000cuft space? How reliable is the more complex Rythmik design?

FWIW I've also spoken to Epik and they seem to think the upcoming $500 300w dual 12" driver Legend with its lighter drivers will fill that 3000cuft space just as well and go just as low or lower than either the E15 or ULS-15. Any thoughts on this? I can wait until September if that claim holds water. Please note that I do not have room for an Empire or dual Legends. This is not my primary listing room and if I can get away with a $500 Legend without feeling bass deprived I'm more than willing to wait. Thoughts?

This is where the sub will go and why space (depth) is limited:

 

[WmAx]

For $1100, you could do an assembly of pre-made cabinet, high performance driver(much higher than the ones included in the subs above) and component amp yielding both higher SPL and higher fidelity sound at that raised SPL.

Just a FYI.

-Chris

 

[shadyJ]

I have some ULS's and love them. I have no doubt the Rythmiks would be great subs too. You can't go wrong with either. This guy is selling a rosewood ULS in the audioholics classified right now, drop him a email, that is a terrific price. As for the legend, it may very well do the trick for you, but I don't think it will match the performance of the ULS or Rythmik, although I would love to do a comparison. Two moderately powered 12"s vs a high excursion 15" with twice the amp power? Sounds like the guy at Epik is just saying whatever it takes to make a sale, although I am sure the Legend will be a good sub.

 

[sholling]

I have some ULS's and love them. I have no doubt the Rythmiks would be great subs too. You can't go wrong with either.

So no problem filling 3000cuft? Plenty tight and musical?

This guy is selling a rosewood ULS in the audioholics classified right now, drop him a email, that is a terrific price.

Thanks I saw that and will give it some thought.

As for the legend, it may very well do the trick for you, but I don't think it will match the performance of the ULS or Rythmik, although I would love to do a comparison. Two moderately powered 12"s vs a high excursion 15" with twice the amp power?

That's something that I'm trying to get my arms around. Brian from Rythmik told me that two of his 300w 12" subs would produce 1-2db more than a single 600w 15". That makes sense because of the extra area. two 12" drivers equals 226sq inches. One 15" only equals 154sq inches. On the other hand I don't know enough about speaker design to understand how that translates to two 12" drivers powered by a single 300w amp.

 

[sholling]

For $1100, you could do an assembly of pre-made cabinet, high performance driver(much higher than the ones included in the subs above) and component amp yielding both higher SPL and higher fidelity sound at that raised SPL.

Just a FYI.

-Chris

Thank you Chris. That's a project that I don't really feel comfortable tackling just yet.

 

[darien87]

I've been doing some preliminary research on compact 15" sealed subs for a 3000cuft room and have become intrigued by two subs: Rythmik's E15 and Hsu's ULS-15. Both are compact sealed subs with 15" drivers.

The Rythmik is a servo design rated at 600w and has a reputation for a very-very tight musical sound but a limited frequency response of 14-80hz although some depute that they will really go that low. .jpg[/IMG]

My Rythmik 12" has appreciable output to 16hz, so I don't think the 15" being able to do 14hz is an outrageous claim.

 

[sholling]

My Rythmik 12" has appreciable output to 16hz, so I don't think the 15" being able to do 14hz is an outrageous claim.

So how does the Rythmik compare with conventional subs?

 

[billy p]

Rythimik might dig deep and offer decent SQ...but I was told they lack high output...fwiw.

 

[shadyJ]

So no problem filling 3000cuft? Plenty tight and musical?

Properly placed and calibrated, yes they will fill that space easily.

That's something that I'm trying to get my arms around. Brian from Rythmik told me that two of his 300w 12" subs would produce 1-2db more than a single 600w 15". That makes sense because of the extra area. two 12" drivers equals 226sq inches. One 15" only equals 154sq inches. On the other hand I don't know enough about speaker design to understand how that translates to two 12" drivers powered by a single 300w amp.

Two Legends ought to have more SPL than a single E15 or ULS, but a single one, I would not guess so. I can't believe the Legend drivers would have the excursion capability of the Rythmik or especially the ULS driver. But then, I am just guessing here. Remember Epik has to put two of these drivers in each sub and keep their costs down. I would surmise from this that the drivers individually are not going to be heavy duty excursion monsters. While the Rythmik guy certainly knows a lot more about subwoofers than I do, I have a feeling he may be omitting certain numbers in order to promote his product.

 

[darien87]

So how does the Rythmik compare with conventional subs?

I've only had 2 other subs, a Boston 10" and an Earthquake 10". The Rythmik blew both of those away.

The Rythmik is indeed very musical and clean. It might not have quite the tactile feel of a 15", but it's a great sub for the money. In fact, I would say that my Rythmik plays louder than my DIY 15", but that might have to do with placement and room modes. The 12" is right behind the couch and the 15 is across the room. But I think something is amiss because we have a plant on top of the 15" and quite often I will see the plants leaves shaking, but not really hear any bass from the 15". I'll spend more time trying to get the 15" dialed in when we move to the new house.

 

[sholling]

I think I've decided on the Hsu. Now I just have to save a bit and get my Bostons sold to pay for it. Thanks everyone for your help!

 

[j_garcia]

The Rythmik is indeed very musical and clean. It might not have quite the tactile feel of a 15", but it's a great sub for the money. In fact, I would say that my Rythmik plays louder than my DIY 15", but that might have to do with placement and room modes. The 12" is right behind the couch and the 15 is across the room. But I think something is amiss because we have a plant on top of the 15" and quite often I will see the plants leaves shaking, but not really hear any bass from the 15". I'll spend more time trying to get the 15" dialed in when we move to the new house.

Yes, I think your problem is your room.

 

[shadyJ]

While the Rythmik guy certainly knows a lot more about subwoofers than I do, I have a feeling he may be omitting certain numbers in order to promote his product.

Oops, I screwed up, I meant to say the Epik guy, not the Rythmik guy. I think the Rythmik guy is on the level with you.

By the way, as I am sure you know, placement is important toward getting the most out of your sub. The guys at Hsu are happy to help you find the optimal placement for the sub, they are very good at it, so if you end up getting a Hsu, ask for placement advice. They have a message board on their website for that, if you also wanted setup advice from other Hsu owners too, which is nice.

 

[sholling]

I made a decision

I went with a Hsu Research ULS-15. I haven't gotten it dialed in yet and I need to experiment with two other spots but so far I like it. No it doesn't go with anything in my room but they gave me a heck of a deal on a b-stock (I can't find the flaw) unit. I'm now officially on a tight budget until next year. Oh and the two T250s are now in my less than 2000cuft home-office.

 

[shadyJ]

Nice looking setup! I have a couple questions: do you think that bass isolation pad helps with a side firing sub like a ULS? Also, do you find any difference in the sound with the sub elevated rather than on the ground? I'm not trying to criticize, I am just curious. If Hsu sent that demo disc with it, playback the first track, the Saint Saens organ symphony at a high volume, to see what the sub can do. It's a very nice clean recording that hits some massive 16 hertz notes on the pipe organ, you will see some serious woofer excursion in those low frequencies. This is where the ULS spanks my VTF3's, the VTF3's do not sound as clean as the ULS at those lowest notes, they can play those notes back but you can tell they are straining as opposed to the ULS.

 

[sholling]

Nice looking setup! I have a couple questions: do you think that bass isolation pad helps with a side firing sub like a ULS? Also, do you find any difference in the sound with the sub elevated rather than on the ground? I'm not trying to criticize, I am just curious. If Hsu sent that demo disc with it, playback the first track, the Saint Saens organ symphony at a high volume, to see what the sub can do. It's a very nice clean recording that hits some massive 16 hertz notes on the pipe organ, you will see some serious woofer excursion in those low frequencies. This is where the ULS spanks my VTF3's, the VTF3's do not sound as clean as the ULS at those lowest notes, they can play those notes back but you can tell they are straining as opposed to the ULS.

Thanks! The isolation pad helps a bunch when it's up on furniture because it keeps the furniture from rattling. Unfortunately that spot didn't work out and I've since moved the sub to a place on the floor where it doesn't need the pad. I only had it up on the dresser to begin with because the T250 that I had before was as directional as a megaphone. If you couldn't see the driver you weren't getting much bass. Fortunately the Hsu isn't directional at all and I still have two more places to test it at. So far it's having no problem rattling furniture from across the room.

Oh and no I didn't get a demo disc.

 

[shadyJ]

Check the packing envelope pocket on the box for the disc, sometimes they hide it there. Maybe you can ask them to send you one if it isn't there, it is a pretty neat disc.