Rythmik Audio F25 Direct Servo Subwoofer First Look

ntrain42

ntrain42

Junior Audioholic
It uses lighter, more sensitive drivers that have less X-max than the FV15 or F15. That is why it can get away with a 600w amp.
No, it uses the same DS1501 drivers as the FV15 and F15, both of which use a 300 or 370 watt amp. The F25 is basically 2 DS1501 drivers using a single 600 watt amp instead(300 watts per driver).
 
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cantonguy

Junior Audioholic
Really? I would think that separate boxes would be better. If they were the same why would spend $500 more for two F15's than $1300 F25. Not that I don't believe you... but I would like to hear anyone else opinion on this. I know if you co-locate 2 F15's you get a 6db increase over a single F15.
 
ntrain42

ntrain42

Junior Audioholic
Really? I would think that separate boxes would be better. If they were the same why would spend $500 more for two F15's than $1300 F25. Not that I don't believe you... but I would like to hear anyone else opinion on this. I know if you co-locate 2 F15's you get a 6db increase over a single F15.
Because with 2 F15's you have the ability to smooth the room frequency curve out. With one F25, your not going to be able to tune and smooth the bass response out as well. Also, technically with 2 F15's you do gain a modest 150 watts roughly in output, as they typically use a 375 watt class A/B plate amp vs. the 600 watt Class H plate amp.

So 2 F15's get you 2 375watt class A/B amps with 2 DS1501 drivers in their own seperate enclosures.

An F25 gets you one big enclosure using 2 DS1501 drivers and a single 600 watt plate amp.
 
Matt34

Matt34

Moderator
No, it uses the same DS1501 drivers as the FV15 and F15, both of which use a 300 or 370 watt amp. The F25 is basically 2 DS1501 drivers using a single 600 watt amp instead(300 watts per driver).
Sorry, should have been more specific. The reason it's "cheaper" is it uses the less expensive DS1501 drivers and not the more expensive DS1510 used in the F15HP, etc.
 
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cantonguy

Junior Audioholic
Because with 2 F15's you have the ability to smooth the room frequency curve out. With one F25, your not going to be able to tune and smooth the bass response out as well. Also, technically with 2 F15's you do gain a modest 150 watts roughly in output, as they typically use a 375 watt class A/B plate amp vs. the 600 watt Class H plate amp.

So 2 F15's get you 2 375watt class A/B amps with 2 DS1501 drivers in their own seperate enclosures.

An F25 gets you one big enclosure using 2 DS1501 drivers and a single 600 watt plate amp.
Would you go 2 F15's over a single F25 then?
 
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TheGovernment

Enthusiast
I wanna know how it compares to the SVS PB-13 Ultra.
There is a big thread over at Emotiva. A dude had bought this after he sold his 13 ultra, was not satisfied with it for HT, he said the 13 had more output. He also said the rythmik was great for music. Apparently he sent the rythmik it back. Ntrain is on there alot I see, lots of posts.
 
R

Rythmik

Enthusiast
HSU ULS 15? You asked. :D
It was really not clear if that -1db ULS15 claims was in-room or anechoic. This also reminds me that Hsu and a bunch other companies like to use short-term max power. That was very vague. In the long run, it just confuses and hurts consumers. We really should standardize power rating method so they are all comparable on the same basis.
 
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Rythmik

Enthusiast
Would you go 2 F15's over a single F25 then?
I will. It is way too difficult to move that F25, not just for you, but also for myself.

Put things in perspective, F25 is for those with tight budget and don't need to move subs very often.
 
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Rythmik

Enthusiast
That's it. His verdict is deeeeeeep in the thread.


These are both on my list of possibilities for my next upgrade and I'd love to see this site do an in depth real world (not benchmark) comparison. A comparison that covers music and action movies. I love sealed subs for music but have never heard one that didn't sound a bit compressed during action movies or could produce an explosion with authority. I'll defer to your expertise but I think it goes beyond overhang and into a boom or thud sounding like a BOOM! or THUD! instead of a boom or thud. I haven't heard either but since I'm 50:50 movies and music like the emo reviewer a FV15HP (or two) seems like it would be a good compromise.
BTW overhang does affect the perception of outputs. That is one reason we got one single BOOM as the overhang just connects all the subsequent detail into one single note. A lot of perception of loud bass is also related to distortion and "noise". In particular the latter. Customers who move from vented subs to our sealed subs notice that a bunch of background noises that they used to hear on vented subs are now gone. Things just got cleaner and they can hear detail better. That is an indication of improvement. We can hear all these differences even at normal listening level and for me vented subs are always slightly boomier/noiser to the degree that they mask detail (BTW, Ethan and Adam are very enthusiastic about FV15 sound and they describe it as fast and stop on a dime, no, actually stop on a needle). Of course when you overdrive a sealed sub beyond its capability, it sounds compressed. But as long as you operates within the linear range of sealed subs and you calibrate both a vented sub and sealed sub to the same SPL reading, the vented sub should sound more like BOOM and sealed sub sound more like boom. And if you like BOOM instead of boom, then you should go with vented subs. I like sealed subs because for me, if a sub does it right for 99% of the natural sound that we have live experience with, then I have more confidence that maybe that boom (account for the remaining 1%) is indeed a more accurate reproduction.



Here is my recommendation. If you don't care detail, but look for a clean sound and also want to play loud, just go with vented. If you care about detail, then get multiple sealed subs.
 
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Theresa

Junior Audioholic
ported, a bad decision?

I am assembling two subs. One has a 12" driver the other a 15". Both have passive radiators. I probably should have gone with sealed but since I didn't I am going to tune them real low. Hopefully that will help them act like they're sealed. Having two will limit room node effects, as I know from having the 1259s. I should have bought the 15" HO Rythmik kit. Always looking for a bargain and then wasting money. These drivers are very good though, Exodus Shiva X2 and Tempest X2.
 
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TheGovernment

Enthusiast
Those are amazing drivers Teresa, I wish I had a couple of them too!
 
ntrain42

ntrain42

Junior Audioholic
Would you go 2 F15's over a single F25 then?
Myself personally if budget is not an issue, Id do the 2 F15's. 2 subs placed in differing room locations can give better in room response over a wider area. But if you only have room or the budget for one sub, go with the F25. Its SQ is identical to Rythmik's other sealed products which are all audiophile quality and can be used with the very best monitors and towers.
 
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scott911

Full Audioholic
night train guy - (or rythmyc guys)

this thread is amazingly informative... thanks

I saw in a signature that you have a pair of downward firing sealed subs. Can you explain why that's the option you choose over a similiar sized side-firing option?
 
ntrain42

ntrain42

Junior Audioholic
night train guy - (or rythmyc guys)

this thread is amazingly informative... thanks

I saw in a signature that you have a pair of downward firing sealed subs. Can you explain why that's the option you choose over a similiar sized side-firing option?
I use a pair of down firing subs in one setup where I want to reduce localization of the subwoofer as they are used with larger monitors. In the other setup which does double duty as HT and audio, I wanted front firing higher output(for HT) subs to blend in better with smaller monitors that require a higher crossover point.
 
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tigerissmiling

Audiophyte
F25

Hi Brian,

do you have a plan to upgrade F25?

will you give it a new Amplifiers which has a higher output?
 
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raynist

Junior Audioholic
So this is never getting a pro review or did I miss it?
 
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User5910

Enthusiast
I would love to see a review of this or any of the Rythmic sealed subs, especially since the amp protection glitch in the FV15HP review messed up the SPL results. Even so I've ordered an F15 for my 1,600 cu. ft. room and I'm looking forward to setting it up.
 
eljr

eljr

Audioholic General
I would love to see a review of this or any of the Rythmic sealed subs, especially since the amp protection glitch in the FV15HP review messed up the SPL results. Even so I've ordered an F15 for my 1,600 cu. ft. room and I'm looking forward to setting it up.

and this is still not reviewed?

Is this by design?
 

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