[floresjc]

I've been speaking with Jim about building a 15" Rythmik servo sub to match my ST, and originally, we though our only real choices were sealed or vented per Rhythmik. I talked to the Rhythmik guys the other day, and asked about a passive radiator option, was it doable, and they told me that the latest simulations said that passive radiator and vented designs were very close, so Jim and I could choose to use the vented design but use passive radiators instead. They also said passive radiator had generated quite a bit of interest it seemed.

Just wondering for the Rhythmik fans, have you heard or seen a 12 or 15" servo design with dual passive radiators? I think Jim and I are both on the same page thinking it might be the ultimate Rhythmik option, but I can't really comment having never heard one.

[Nuance]

Since my name is in the title, I suppose I should respond. 

At the SE WI subwoofer GTG we all had the pleasure to hear a prototype Rythmik ported subwoofer.  It was nice, but the sealed was better in every way except ultimate depth and perhaps max output.  However, coupled with room gain the sealed version should clear that issue right up. 

A passive design sounds great when done correctly, but it does have a different sound than both sealed and ported.  It obviously has no issue with port noise, but it's not as tight as a sealed design.  I heard my first passive design (built by John Jonowitz) at the above mentioned GTG.  In short, it was my favorite subwoofer of the day along with the LMS 18" DIY sealed.  It was a 15" with 18" passives - very impressive. 

Jim is a pro, and one of the best there is in the business, so if he can build a passive I say go for it.  If it sounds anything like the one John from Acoustic Elegance made, you'll be VERY happy. 

Real quick, I am pretty much anti-ported now that's I've had a chance to compare a bunch of subwoofers.  However, the SVS PB13 Ultra is the exception.  I'd be honored to own that subwoofer. 

Hope that helps.  I say go sealed or passive.  I'm runing dual DIY 15" TC2000's right now and I'm lovin' it!  Whichever you go with, I think you'll be very happy.  The sealed rythmik rivaled the much more expensive JL Audio Fathom 112 except for max output.  I wish Rythmik could use a bigger amp, or at least offer it as an option (even though it would be a much more expensive option).

[floresjc]

Ported is out for me, I don't want the port noise, and I'm not looking for ultimate output. I was kind of fixated on the PC13 Ultra, because of the small footprint and its high reputation. Compared to a Rhythmik, it probly has more rumble, but will not be as musical. Considering my avg size room and moderate listening levels, the sealed or passive Rhythmik is my choice.

I don't believe Jim has built as passive radiator rhythmik design yet, and I'd be willing to be the first, but I'm not sure if I would need the extra oomph considering the extra dollars it would cost. I've got some time yet to decide.

[TJHUB]

Ported is out for me, I don't want the port noise, and I'm not looking for ultimate output. I was kind of fixated on the PC13 Ultra, because of the small footprint and its high reputation. Compared to a Rhythmik, it probly has more rumble, but will not be as musical. Considering my avg size room and moderate listening levels, the sealed or passive Rhythmik is my choice.

I don't believe Jim has built as passive radiator rhythmik design yet, and I'd be willing to be the first, but I'm not sure if I would need the extra oomph considering the extra dollars it would cost. I've got some time yet to decide.

I really liked the Rythmik I heard at merrymaid's house.  It sounds really good for music.  I didn't get to hear it loud, but it is very tough for a sealed sub to dig deep and get loud.  Since I use my sub for both music and home theater, I need performance. 

I know Jim doesn't build this, but you should consider an HSU ULS-15.  I'd love to hear one (or two) in my home.  If I were to ever give up my PB13-Ultra, the ULS-15 is currently the only sub that interests me. 

To be completely honest, I was not all that impressed with my PB13 for music until I paired it with my HT2-TLs.  My sub was to be the next upgrade, but I just can't hear any reason to upgrade it now.  It is flawlessly transparent when listening to music and it can nearly destroy my house for home theater.  What could be better? 

[Nuance]

  What could be better? 

HT4's and three Seaton Submersive's... 

[Rocket]

Hi,

Pardon my total ignorance but how will a passive radiator work in a subwoofer?  Does it have an xover that is connected to the speakers?

I understand how a powered subwoofer but I have no idea how a passive one would work.

Have you been told how much the rythmic sub will cost thru Jim?

Regards

Rod

[doug s.]

whatever sub you decide on, i strongly suggest you get two, and an active x-over so you can relieve your st's and their amp of having to see that last octave.  two subs will outperform one in many ways - less distortion, higher output, easier room integration.  and, actively crossing over your st's will improvetheir performance as well - the amp driving them, and their midwoofers will perform better at all frequencies, when they don't see anything below the chosen x-over frequency.

doug s.

[doug s.]

Hi,

Pardon my total ignorance but how will a passive radiator work in a subwoofer?  Does it have an xover that is connected to the speakers?

I understand how a powered subwoofer but I have no idea how a passive one would work.

Have you been told how much the rythmic sub will cost thru Jim?

Regards

Rod

a passive radiator is yust an unconnected driver that is used instead of a port.  it moves (in the opposite direction) as the active driver moves.

doug s.

[DMurphy]

Hi,

Pardon my total ignorance but how will a passive radiator work in a subwoofer?  Does it have an xover that is connected to the speakers?

I understand how a powered subwoofer but I have no idea how a passive one would work.


Regards

Rod

This always gets confusing.  In this case, passive refers to the use of passive radiators--slave woofers with no motors--instead of ports.  It would still be a powered subwoofer.  The box is tuned so that the slaves will contribute to the bass output over a portion of the frequency spectrum.  Passive radiator systems gained a reputation for "slow" and heavy sound because the box tuning wasn't optimized for them.  But there's no need for that result any longer, and they are a viable alternative to ported and sealed designs, particulary for subwoofer drivers with very high excursion capabilities.   And Nuance--if you could magically appear at my DIY get together in July, I think I could prove in 5 or 6 seconds that a passive system (the Beast's bass module) can sound just as tight as the best sealed design. 

[Nuance]

^ I'd like that, but it's quite a trip.  I'll see what I can do, though.  Thank you for the invite!

I don't doubt a passive can sound like a sealed subwoofer, though.  I was just posting about the one and only unit I've heard.    Also, I should clarify that the passive did sound like a sealed unit sometimes, but at others (like different decibels and frequencies) it had a different sound.  It sounded a little slower and sometimes more hefty. 

[sfox7076]

I plan to do measurements of my Rythmik Salk tomorrow.  Work has killed me.  A Bankruptcy Lawyer in NYC gets no rest these days.  I cannot complain because it is work I like, but man I am busy.  My actual ear observations are that the sub is very accurate.  Much more accurate than the HSU I had.  The sub does not get as "loud" when things explode as the HSU, but you can feel it.  It is much more accurate as you can distinguish the more of the explosion if that makes sense. 

Shawn

[Nuance]

Yes, it makes perfect sense.  I know just how you feel and look forward to the measurements.  Do you plan on using REW or another program?

[Jeff B.]

Thanks, Dennis. I take that as high praise.
Jeff

Hi,

Pardon my total ignorance but how will a passive radiator work in a subwoofer?  Does it have an xover that is connected to the speakers?

I understand how a powered subwoofer but I have no idea how a passive one would work.


Regards

Rod

This always gets confusing.  In this case, passive refers to the use of passive radiators--slave woofers with no motors--instead of ports.  It would still be a powered subwoofer.  The box is tuned so that the slaves will contribute to the bass output over a portion of the frequency spectrum.  Passive radiator systems gained a reputation for "slow" and heavy sound because the box tuning wasn't optimized for them.  But there's no need for that result any longer, and they are a viable alternative to ported and sealed designs, particulary for subwoofer drivers with very high excursion capabilities.   And Nuance--if you could magically appear at my DIY get together in July, I think I could prove in 5 or 6 seconds that a passive system (the Beast's bass module) can sound just as tight as the best sealed design.

[DMurphy]

Thanks, Dennis. I take that as high praise.
Jeff

Naaa--just an accurate description of the sound.  I wish you could magically appear as well to take credit for and hear first hand how your simulations turned out. 

[evan1]

Shawn
I did not realize you are a fellow New Yorker. What, no invite to hear the sub?

[Kris]

I think we need some Salk Summer events for the NY five boro area. 

[bigbwb]

As the owner of the 15" Rythmik nuance & TJHUB heard, I figured i would chime in.  I love my Rythmik and feel its great for music and just as good for HT unless you have an extremly large room to fill, then you will just need more than 1   The nice thing about the Rythmiks is how you can buy two of them cheaper than one JL f112 and have more output and still save some $.

I have owned 2 HSU's and two SVS's with the last one being the PC Ultra 12".  The Rythmik beats my last SVS in every category and with music, the detail(how quick the subs driver reacts to changes in the song and its different frequencies & etc) is in another league all together.

I do need to hear Terry's(TJHUB) SVS PB13, whens that GTG happening again   oh, and not to mention your HT2 TL's.

Brandon

[jtwrace]

I've been following this thread...

I can't say enough positive things about the Rythmik kit and Brian.  Great products!  I built them first in an MDF enclosure then decided to do this after such great results.  Sorry for the link but posting again didn't seem proper (takes space).

http://www.audiocircle.com/index.php?topic=68426.0

[Nuance]

Good point, Brandon - two Rythmik 15 inchers cost less than a JL, have more output and sound just as good.  Wow - that one's a no brainer!