Official Rythmik Audio Subwoofer thread - Page 249

Originally Posted by Rythmik 

The one we published is done outdoor and nearfield (meaning the mic is literally 2" away from the cone with a windscreen to protect cone hitting the mic). So it is much smoother and reliable. The close mic done in room will still have nulls and peaks. Another fact is the published curve is for DS1501/DS1510. DS1505 has also a bit more midbass output as I mentioned it has a better up end extension even in LINE-IN mode as compared to DS1501 and DS1510. And whenever there is a design choice, my design choice is that I will let the upper bass of LFE input be a bit more prominent so that customers can get a bit more "midbass slam" in LFE mode (ie, having more fun). But the emphasis should be within acceptable range.

Originally Posted by Rythmik 

Dave, you have a PM quesiton about what happen if we mistakenly install a vented version amplifier on an F15/F15HP. The answer is the FR will start roll-off around 40hz. That is what you will see on the so-called "sealed mode" of ported subs from other vendors. We don't offer sealed mode in FV15/FV15HP for exactly the same reason (and plus others).

Originally Posted by Rythmik 

I can send a set of screw-in rubber feet to you. You can put felt on the rubber feet, then you don't damage the finish. I haven't started including rubber feet on every F15/FV15 subs mainly because we only have a limited supply of those. I expect to have far more come in during Jan. Then we will include them as standard. If any customer need them right away, just shoot me an email.

Originally Posted by Kruppy 

Does any printed information (owner's manual) come with the sub? The original owner thinks he discarded it. I'd like to find a copy, if it's worthwhile.
Please correct me if I'm wrong, I remember that there is also a setup guide on the Rythmik website, however, I can not find it. My seaches in this thread have come up lacking. Can someone point the link out to me?

Originally Posted by David_R 

The only thing I know of is the 1-page amp "quick guides". There's a few different ones (depending on which amp), and they're not all linked to from the same place. Here's the ones that I found:

• PEQ3 sealed (same for A370, H550, and H600, I believe)
• PEQ3 vented (same for A370, H550, and H600, I believe)
• PEQ2 (same for A370, H550, and H600, I believe)
• A370PEQ (don't know if there was ever an H550/H600 version)
• A370XLR (don't know if there was ever an H550/H600 version)

I didn't find PDF's for the XLR2 or XLR3 amps, but I think they've been discussed in this thread.
Hope this helps,
-- Dave

Originally Posted by Cowboys 

^^
FV15HP

Originally Posted by audionuts 

I have dual fv15hp and they are doing a very good job on both music and HT. Rythmik ported sub is nearly as good as any sealed sub out there in term of tightness and midbass punch.

Originally Posted by DonH50 

Handwaving subjectivitis post:
The FV15 is ported so offers a little higher output but less extended LF below the port frequency. The F15 is sealed so does not roll off as fast, offering a bit deeper bass. Both use the patented Rythmik servo (feedback control) loop so performance is pretty comparable and much better than many other subs. Sealed designs generally offer a little better sound as the cone movement is better controlled; Brian says he can tell a slight difference comparing ported to sealed using his servo design. I rather doubt I could. There is the potential for port noise (a sort of "chuffing" sound) with any ported design but for a good design used within its limits that is unlikely. The HP version of either provides a more powerful amplifier and longer-throw speaker (driver, cone) that adds perhaps 2 - 3 dB, a difference you are unlikely to hear and only a small increase in headroom.
Search this thread and the Rythmik web site; Brian (the owner and designer of Rythmik) has posted both response graphs and tabulated the output of various subs in the line.
I would guess the F15 would do movies just fine. The trend I have observed is for folk to buy the biggest, most powerful model with the idea of "future-proofing" and not wondering later if they might have benefitted from more power etc. I suspect the vast majority are succumbing to testosterone rather than knowledge or listening, but so it goes... Perhaps that is just my own ego speaking, since all I own is a pair of puny little F12’s… They do shake the walls in my modest room.
FWIWFM - Don
p.s. I would advocate a pair of subs for a large space, or evena small space, to help smooth out the response.

Originally Posted by JHAz 

FWIW, Brian from Rythmik posted the folllowing in a subwoofer shootout thread hereabouts a year or so ago:
At 20 Hz, our subs vary in their maximum output capability. The output at 20 Hz is shown relative to F12.
F12: 0db (baseline)
F15: +2db D15: +2db
FV12: +3db
E15HP: + 3.5db
F15HP: +4db
FV15: +7db
FV15HP: +9db
So the FV15 will be about 5 dB louder at 20 Hz. The advantage goes away as you increase in frequency. It's stuck in my head that Brian has suggested max output is similar once you get to around 50 or 60 Hz, but I could be remembering wrong.
Also, what DonH says above.
I guess the other thing I'd add is that at a sub shootout in Kansas City semirecently, nobody could accurately tell whether a sub was sealed or ported just by listening (when the subs were behind the curtain with the Wizard). So while there apparently are differences that at least trained listeners can hear, my overall (and surprising to me) take is gravitating toward, "if a sub is well designed whether it is ported or sealed will not result in a significant audible difference, if they are operated within their linear ranges." But my bias remains, "I'd do sealed if I can get adequate output at an appropriate cost." But I realize it's really a bias, like my preference for using lossless soundtracks where available although I know, intellectually, that the higher bitrate lossy codecs present on BluRays are likely sonically indistinguishable from the lossless, especially in my imperfect room at my (-10 to 20 dB from reference) listening levels.

Originally Posted by DonH50 

Thanks for finding the info, JHAz. I had forgotten there was such a difference in output from the F12 to FV15HP (which was not available when I got my F12's, probably a good thing). Note the loudness curves compress at LF so a difference of 5 dB or so is likely to sound twice as loud, not that it matters all that much unless you really need that extra headroom.
IIRC, for well-designed subs and especially using servos, the only real significant difference between ported and sealed in normal operation is the ported models will roll off faster than the sealed. Since that frequency is so low on these subs I doubt anybody can tell. I think the difference in SQ is very small, again likely indetectable at such low frequencies.
IME, poor ported designs are readily detectable by their higher distortion and/or port noise. Most ported designs do just fine at normal or even unreasonably high listening levels.
FWIWFM - Don

Originally Posted by woody777 

Thanks everybody!
If I can only purchase a single sub, but my room is big (4000 cubic feet not including opening up to a kitchen and dining nook), do I need the extra db from the bigger amps or ported designs? I never listen at reference volume -- it's just too loud for me.
I'm coming from a Klipsch RW-12D. I think it was a combination of poor placement (this was at an old house -- I just moved) and not spending enough time dialing it in, but I was very disappointed. It sounded alright for movies for some low rumble, but I just couldn't get any power or thump for music. Unless I really cranked my system, I sometimes wasn't sure if it was on.

Originally Posted by woody777 

Any single sub in the Rythmik line is within budget. I just can't do dual subs. The space is so big because of the vaulted ceilings, but it's a family room and dual subs would just be too much. I plan on selling the Kipsch.

Originally Posted by Kruppy 

As of yesterday evening, I have finally joined the Rythmik Nation (J. Jackson pun intended). I would have liked to buy new from Brian and support his company, but finanically I just couldn't do it at this time. So, with my wife's blessing after intense negotiations, I drove 80+ miles one way and picked up a used F15HP (8 months old) last night. I feel pretty lucky, as I've been looking for a used F15HP or FV15HP sub for a long time and have never seen one for sale local to me within a 2-3hr drive.
I do have a couple of questions for everyone.
Does any printed information (owner's manual) come with the sub? The original owner thinks he discarded it. I'd like to find a copy, if it's worthwhile.
Please correct me if I'm wrong, I remember that there is also a setup guide on the Rythmik website, however, I can not find it. My seaches in this thread have come up lacking. Can someone point the link out to me?
I'm unfortunately sub-cable-less until tomorrow, but this weekend will be a good one.....

Originally Posted by zycomatique 

Hi!
I'm trying to contact rythmic audio via their website but there's no answer! Is there a problem with this brand?
Thanks: David

Originally Posted by qguy 

None, but the other brands has a problem with this brand

Originally Posted by woody777 

Thanks everybody!
If I can only purchase a single sub, but my room is big (4000 cubic feet not including opening up to a kitchen and dining nook), do I need the extra db from the bigger amps or ported designs? I never listen at reference volume -- it's just too loud for me.

Originally Posted by polizzio 

Hey congrats! You're gonna like the F15HP a LOT. Just a reminder, no need to spend big bucks for a subwoofer cable. Amazon has some good choices at great prices if you need a longer cable and can wait for delivery, or newegg too.

Originally Posted by audionuts 

^^^
FV15hp is big and powerfull. It will suite your space well. My wife once said ”....With the black piano finish and silver cone, it is quite nice and making me forgive its gigantic foot print.....”

Originally Posted by Skylinestar 

@ woody777
I suggest you get the biggest, meanest sub from Rythmik...aka FV15HP. A few months down the road, you'll be addicted and telling yourself to buy another FV15HP. You have a very big space to fill, hence the need for more power.

Originally Posted by skriefal 

I have a single FV15HP in a space at least that large. I also listen at less than reference level. The FV15HP is plenty for my needs, and the same will almost certainly be true for you.
The FV15HP was nearly rattling my closet door off its hinges while viewing the "Darla" scene in Finding Nemo a few nights back.

Originally Posted by jonathanc 

Hey Brian,
Any thoughts on using a Rythmik DIY kit in a Folded Horn or Tapped Horn box like the Danley DTS or Bill Fitz Tuba HT ?

Originally Posted by jheyau 

^^^
Perhaps Brian can comment on the soon-to-be-released F25s with 800 W amp. I think they can easily compete with the JL f113 that you sold. Get a pair of these dual 15" servo subs and you should have some of the very best bass performance for an average audiophile. Of course if you have a deep pocket, stack two or even three F25s per side and proclaim yourself as the king of powerful and articulate bass

Originally Posted by Rythmik 

If he didn't use our servo amp, that is a different story. But if he uses the servo amp I sent him without the servo sensing feedback, it is un-usable because it becomes a current drive amplifier and the output at the impedance peaks just become higher and the output at the impedance nulls just become lower. In other words, to use our amp without servo, the customers have to buy a "non-servo" daughter circuit board to replace the servo daughter board. It is not as simple as just "don't connect the sensing feedback".