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Dual Rythmik FV15 Class A/B Servo Review

post #1 of 23
Thread Starter 
I don't know and have never met anyone at Rythmik, I don't work for them nor do I owe them anything, nor am I being given any value for my review. Brian Ding did answer 5 emails from me and did his best to answer my questions. He is an Engineer and I am a Financial Analyst and a Guitarist (my true love) and also play bass guitar ...he uses engineering terms to describe sound ...I use musical terms to describe the same thing and sometimes, unfortunately give numbers more meaning than I should.

Searching for my first "real" subs led me on a 6 month research quest. I ended up with dual Rythmik FV15's, with the Class A/B amp. I chose the FV15 and NOT the FV15HP because of the Class A/B amp. I did not want the Class H amp in the FV15HP. To "my" ears ...class a/b offers a genuinely musical sound, while Class H to "me" seems ...."robotic", just seems to lack the ability to "breath".

My review is an attempt to thank those that helped me, and to help those in their search. When it comes to home theater, people describe the same thing differently. Engineers have their terms, home theater buffs have theirs ...and musicians have theirs as well. My review comes from the language of dynamics and musicality.

First and foremost I am a tube amp freak, I am a ANALOG junkie. My Home Theater Room is also my Guitar/Bass Jam Room. My number one criteria in search of my subs was "musicality". I did not just want booom ....booooooom .....boooom. When I play guitar I have to be able to track the bass drum and bass guitar, if I can't, I'm lost. I can't have sloppy or undefined drums or bass. More specifically I want to hear the "dynamics" of the bass drum ...the breath of the bass drum ...ie ...pitter, pitter, PAT. Same goes with the bass guitar. My guitar amp is a 22 watt all tube Fender Deluxe Reverb that is frickin loud. My bass amp is a Ampeg Mosfet 500watt head with a sealed 15". ONE FV15 would have out gunned all of my gear, two just gives me complete coverage, and lets me use less sub amp to achieve the bass volume I need.

For those that do not know about power/output ...let's say ONE sub puts out 500w and produces 120db. Doubling that amp's power only increases volume (decibels) output by 3db, in ideal conditions (placement). BUT, it also means that if TWO subs are used, you can achieve the same output as that ONE sub maxed out, with only using "half" of the output capabilities of each of those TWO subs. That is HUGE when considering how "hard" you are driving your sub/subs, and should contribute to longer life. (don't mean to be arrogant, just trying to help those unaware of how huge a factor it is).

Let's face it, subs have a dual purpose. Special effects for movies and bass for music, a quality sub should have no problem doing both. What really intrigued me about the Rythmik Subs were the audio options. 1)Frequency Select: 14hz, 20hz or 28hz. 2)Damping Select: high, mid, low. 3)Port Options: 1 port open or 2 ports open. 4) PEQ: Eq to "smoothe" out peaks/dips. 5)On/Off/Limiter Switch. The other options don't apply to me. After 5 months with the subs, "hear" are my results in my basement home theater/jam room:

The room is rectangular and about 3500cf, with two openings on one side ...one mid wall and one at the rear. Klipsch Reference Speakers (101db sensitivity = loud) powered by a Pioneer Elite (mosfet) Receiver with 120watts x 7 power.
My results? Mind blowing. Spectacular. Exceeded all expectations. I have thrown "everything" at them ...and they don't "budge". They don't strain. It's so amazing.

Every blu ray scene you can imagine ...the subs hit with 1,000% authority. Theres a scene in The Matrix where they pull into an alley, it's dark/gray and it's raining. Neo gets out of the back seat of their car and then slams the door shut. What is mind blowing is the door does not just shut ...you hear the "entrance" of the door "slamming" shut (like a deep whoosh), followed by the "THUNK" of the door shutting, finally followed by the ending bass echo of the door "having" been shut ...all through the subs. Amazing. Saving Pvt. Ryan ...the explosions "slam" you in the chest. SLAM you in the chest. War of the Worlds? The deep infrasonic bass when the pods come out ...it's as if they were "in" the room. U571? I jack with my friends, it's the first thing I hammer them with ...all is good ...until that first depth charge hits ...it "shocks" them ...they immediately look at me stunned ...then another depth charge ...then another. Their like holy sht. When they leave my basement it's as if they were in those movies while at the same time they were running a marathon. They are wrecked.

Music: I mostly play blues, rock, 80's metal and 70's pop rock. More bass then I could ever want. What's really killer for me is, all those old albums that did NOT have a lot of bass volume, they do now (you know albums with ego guitar players who had to be heard over anything Vanhalen, Iron Maiden, Scorpions, etc. Listening to Rush 2112 is a totally new experience, every, I mean every nuance of Neil Peart's bass drum comes through in total perfection. Sound Garden with these subs is mind blowing. Finally I can feel the bass drum and bass guitar on par with those raging stacks that used to scream in my face. Tool? Chuka dunna, Chuka dunna. Those bass lines are infrasonic sledgehammers! Hip/Hop, Rap ...out of this world BOOM!

Every single one of my friends basically crap their pants when they experience these subs. Placed in front, out from the side walls about 3 feet, the couch is 12 feet away, they can blow your hair! What's really a trip is ...it shakes the couch ...this trippy infrasonic type of shake ...you know that bass so low you can't hear it ...but your body is vibrating along with the couch. I didn't mean to, but I've blown out light bulbs ...and knocked down popcorn from the ceiling, and blown picture frames sideways.

The audio options are subtle (thank god), but actually work, and work well. The subs are naturally tight to begin with b/c of the servo control (another reason I went with the Class A/B amp and not the Class H amp. I've found the Mid setting is as tight as I need for music. If I want BOOM for movies, frequency down to 14hz, one port open and damping on low. If I want ultra tight and dynamic punch for music ...frequency at 28hz, both ports closed and damping on high ...and still deep powerful bass. I haven't even mentioned the PEQ. I don't have a frequency analyzer ...so I did it by ear ...subtle but just seemed to "smoothe" out the response.

I very well may have been satisfied with a few of the others subs that made the final three on my list. But, I am overwhelmed with what Rythmik sent me. The ability to produce sheer volume and punch with complete control over the dynamics WHILE also having the ability to stuff a port, flip a couple of switches and shake my foundation with infrasonic bass is mind blowing. What may be most impressive is that the subs do ALL of this with out any strain or effort, this gives me peace of mind knowing this will contribute to a longer life span. I honestly don't have a single complaint, not one. The price? Sure, I didn't enjoy shelling out the money for two of the subs ...but after experiencing them ...they were worth every sing penny ...and I would do it over without hesitation.

Again, I have nothing to gain from Rythmik Audio/Brian Ding. I simply feel an obligation to share my experience in totality with those searching for "their" sub ...and to let Rythmik know exactly what I liked and how satisfied I am by sharing that satisfaction. Brian was friendly, and spent his time responding to my "jacked" up musical questions about the subs abilities. I also felt a deep desire to do business with a "man", and not a mega corporation. The subs came double boxed and could have been shipped around the world and back without damage. Each box looked like a German Shepherd Dog House, UPS man said he had never delivered a Sub Box like them before, he was stunned when I told him what was inside. They are built like tanks and back it up with musical dynamics, gut pounding punch and foundation shattering infrasonic bass. Zero, absolutely zero buyers remorse and total satisfaction. If there were a negative, it would be the length of the warranty, 2 years. For the price of these beasts, I would have hoped for at least 3 years. I would have paid a little more for a 5 year warranty. Thanks for reading, please feel free to comment or ask questions ...and please forgive me if my review offended you.
post #2 of 23
Nice review, same here I got the AB amp over the H amp, Sealed F15 KIT though, I have not heard the class H amp, so could not really tell if the AB is better, but Class AB has been a proven design and is used in most 2 channel audio amplifer. When did you get your FV15 ?
post #3 of 23
Thread Starter 
qguy: Thanks for your reply. I got my Dual FV15's in April, this year. I was also considering the sealed subs for their amazing response and sound. I hoped that the ported fv15's that i got would be "tight" enough ....not that inferior sloppy booming sound that you get with most ported subs. The ports rythmik subs are amazing. How is your sealed sub? Have your heard any rythmik ported subs?
post #4 of 23
Thread Starter 
qguy: I almost forgot ...class a/b vs class h. I couldn't compare the rythmik's but generally I feel class h amps lack ..."weight" in the sound. Class a/b amps, to me, just have a juicy, deep solid low end, the way it should be. The class h amps lack that, and seem to "connected" to the speaker ...so it does not have the ability to allow "any" dynamics. That's what i hear, others may differ.
post #5 of 23
Have not had the chance to hear the ported Rythmiks, Always had sealed subwoofers so did not want gamble with ported subwoofers.
post #6 of 23
Is the FV15 still available? I thought it was being phased out
post #7 of 23
No the FV15 is not available...the HP out sells it and Brian said there was not much point in carrying 2 subs that are similar. There will be a FV12HP replacing it at the end of the year.
post #8 of 23
Quote:
Originally Posted by qguy View Post

Have not had the chance to hear the ported Rythmiks, Always had sealed subwoofers so did not want gamble with ported subwoofers.

There is very little difference according to Brian and a few others that have.
post #9 of 23
Congrats on the new subs, 57LPB! And thanks for the great write-up. cool.gif

I like my ChaseHT subs, but in my ~3,400 cu.ft. basement HT space I don't get the kind of extension (I can't seem to get below 17Hz) and "slam" I would like. (With the same subs in his ~2,025 cu.ft. basement HT space, my buddy's subs deliver massive amounts of slam and fairly flat extension to 10Hz.)

Dual FV15s sound like what I need. Too bad i) they're not available anymore and ii) the cost of shipping to Ottawa, Canada + taxes and duty would probably be stupid. *sigh* frown.gif

wink.gif
Edited by eljaycanuck - 9/24/13 at 12:40pm
post #10 of 23
I dont want to loose that "little" difference smile.gif I use to have a 12 inch 70 watt sealed M&K and I seldom bottom it out in my 1300 cubic feet room, so a 15 inch 370watt sub is overkill, no need to go ported.... but I did thought about it smile.gif.. imagine having that kind of output in that room ....

I guess, if I started with the ported Rythmik, I would be contented, its just that i don't want to have any "if" in my mind ... Right now, the only "if" thats in my mind is "What IF I have 2 F15 ?" smile.gif

Quote:
Originally Posted by basshead81 View Post

There is very little difference according to Brian and a few others that have.

Edited by qguy - 9/24/13 at 3:48pm
post #11 of 23
Thread Starter 
@qguy: How funny, were opposites! I didn't want to gamble on the sealed. Now, I know I would be satisfied with both. Sheer output was my main concern ...with Rythmik output is not a concern anymore. lol!!!
post #12 of 23
Thread Starter 
I would never, ever disagree with anyone, when it comes to what "they" hear. I may very well be blinded by my loyalty to analog circuitry. But I can honestly say, for me ...maybe it's something that I "sense", but class a/b amps seem to carry a "weight" and produce dynamics better to me. Again, I may be blind.
post #13 of 23
Thread Starter 
What's up Ottowa! Great to have a chance to chat. Rythmik does have the F15 sealed sub with the same amp as my FV15 ported. 370W class a/b. When deciding on my sub purchase, I was close to going sealed. Overall, I was weighing the pro's and con's of sealed vs ported. I felt the ported had enough "control" of the dynamics to suit me as I began to shift my focus to "sheer output". NOW ...after the fact ...knowing how powerful Rythmik subs are ...I know that the F15 would easily provide enough "sheer" output.

Dual Rythmik F15's sealed with the A370peq3 class a/b amp is one "monster" sub. I don't know anything about total cost to you, but worth considering. I had never heard a Rythmik sub before ...now that I have ...it's worth every penny ...and i pinch those pennies tight. Best of luck in your search.
post #14 of 23
Thread Starter 
qguy. your right ...."little" difference ...."subtle" difference ...sealed subs do have "that" something. I think the best way I can describe it is it removes any and all "echo" to the bass. I would even say that sealed subs are better. I still dream of having two F15's sealed to go along with my FV15's. Can you imagine that?
1300cf??? holy cow. Yeah ...that F15 can dominate and control that space easily ...I'm sure it's a beautiful experience.
post #15 of 23
Thread Starter 
One thing I totally forgot ...which is so important ...is the sub speakers "sensitivity" rating. I for sure thought I had asked Brian/Rythmik about it but I can't find it in any emails. Anyone know the Sensitivity Rating on the Rythmik 1505 driver? I know it has to be pretty high for the sub to achieve the volume that it does.
post #16 of 23
Very nicely done. I always enjoy it when someone posts their own personal evaluation of a product they own. Yours was a really engaging read.
post #17 of 23
Thread Starter 
@Jim from Joisey! What's up brother. Thanks for the response. When researching for my subs to purchase ...I found sites like this were the exact resource I needed to help me make the best informed decision I could. Especially considering I could not demo any of the subs I was looking at. I am so thankful for others reviews and their descriptions ...I really hope that "my biased" review can help others. Unfortunately I'm cursed. It's my ears. My eyes are horrible and mere bystanders in life ...but my ears "latch" on to anything and everything. I tried to be thorough without coming across as dictatorial or arrogant. I know my friends, who all love music and home theater, but are not musicians, trip on me when I'm describing sounds. They just look at each other and laugh. Take care JIm ...and keep holding up the East Coast.
post #18 of 23
Quote:
Originally Posted by 57LesPaulBurst View Post

@qguy: How funny, were opposites! I didn't want to gamble on the sealed. Now, I know I would be satisfied with both. Sheer output was my main concern ...with Rythmik output is not a concern anymore. lol!!!
I was looking for a musical sub and went sealed with a D15SE in a 2,500 cubic foot room. I found the D15 to be overkill for my needs but you won't hear me complain. It arrived last Wed and I finally had it dialed in close enough by Saturday night. Like you, I am an analog guy. My turntable recently surpassed my digital front end in sound quality and I love it. My wallet won't when it comes time to upgrade the DAC, plus the recent buying spree of vinyl. tongue.gif My system is set up as analog pass through. There is no digital room correction going on and the waterfall graphs show a stable in room response of +/- 5dB from 17hz to 70hz. I have one problem at 70hz which will soon be fixed with one more bass trap. After that I am back to +/- 5dB from 80hz to 220hz.

This sub is simple to integrate with all of it's functionality. It replaced on old Klipsch 8" ported sub that had an ailing power supply. The port on the Klipsch always created headaches for me by causing phase issues. No more port phase issues for me with the D15. I love it.

The sub had about 30 hours on it by Saturday night so it was time to give it a workout. Popped in the CD layer of Tchaikovsky's 1812 Overture from Telarc SACD. The version recorded with real cannons. Played it as loud as I dared, about 95dB peaks. Loud listening to me is usually hitting 85dB peaks. So I really had it cranked by my standards. I actually laughed out loud when the fist cannon fired. It was amazing. The bass on the previous sub was so distorted that their wasn't that much difference between a tympani drum and the cannon shots. Now, it is obvious. And I love it. biggrin.gif

Tonight it was a mix of samples. Playing loud again, about 85dB peaks. biggrin.gif From Soul Coughing's Supper Bon Bon, to the Pixies, Queen - Killer Queen, and others. The big test was Cowboy Junkies Trinity Sessions to test the decay caused by the size of the room in this recording. The sub filled in nicely making my listening room sound as big as the church where this was recorded. Starting out with the train in the background of Mining For Gold. I've never heard the train so clearly. In the past it was just background noise drowning out the room and the warning bells. Now it is clear as day that it is a train with the crossing bells warning in the background to the song and the hum and rumble of the train mixed with the vocals reverberating throughout the church and my listening room. It sounds amazing.

I'm pretty happy with this sub.
post #19 of 23
Thread Starter 
khyl: you poor man ...you sound as demented/tormented as me! lol!!! It's hard not to sound like a fan boy ...but when I had only had smaller, mass produced, over hyped subs before ...the rythmik is mind blowing. I can actually visualize the sht eating grin on your face as your waking up your sub and bringing her to life. Rock on brother.
post #20 of 23
BTW as for the ported vs sealed, I remember Brian mentioning that if you have a ported sub and the damping is set to medium, the sealed would sound like setting the damping to high. He also mention in the official Rythmik thread that if your running DSP, it would be ideal to set the damping to medium and if the bass sounds flabby after the calibration, you have the option to switch the damping to high.
post #21 of 23
Thread Starter 
qguy: exactly. which is one of the reasons i leaned towards the ported ...that ability to control the damping/ringing of the speaker cone. Still, i find myself dreaming what the "wallop" of two f15 sealed subs would sound like. I would still give sealed subs the edge when it comes to "authentic" bass reproduction.
post #22 of 23
Quote:
Originally Posted by 57LesPaulBurst View Post

qguy: exactly. which is one of the reasons i leaned towards the ported ...that ability to control the damping/ringing of the speaker cone. Still, i find myself dreaming what the "wallop" of two f15 sealed subs would sound like. I would still give sealed subs the edge when it comes to "authentic" bass reproduction.

I've heard both the FV15HP and E15HP myself, and I don't believe you have anything to be concerned about; the FV packs a considerable wallop, so there's really no cause for "subwoofer envy"... tongue.gif
post #23 of 23
Two F15 would produce something like a single FV12, The FV15 is down 2 dB vs the FV15HP, hence why they decided to discontinue the FV15 as its too close the FV15hp. For Ported subs, Fv15 seems to be a great value considering it has the AB amps. Hopefully in the future I would come out with my own review with two F15s biggrin.gif
Quote:
Originally Posted by 57LesPaulBurst View Post

qguy: exactly. which is one of the reasons i leaned towards the ported ...that ability to control the damping/ringing of the speaker cone. Still, i find myself dreaming what the "wallop" of two f15 sealed subs would sound like. I would still give sealed subs the edge when it comes to "authentic" bass reproduction.

Edited by qguy - 9/25/13 at 7:15am
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