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Looking for final advice, Rythmik Subs

6K views 63 replies 16 participants last post by  enricoclaudio 
#1 ·
Room size 11'x15 with 7' ceilings. Its in a basement with 2 windows which are covered up with blackout curtains. 4 doors, one is an exterior door, bathroom door, bedroom door, and laundry room door.

Currently have 2 Sierra 2's for the L/R and ordering another Sierra 2 monday for a center channel along with a rythmik sub. I will eventually go with dual subs but cannot at this current time. its about 90% movies/Games currently and 10% music (which will go up now that I have better speakers)

Rythmic F12 or FVX15. I usually watch movies at around -25db +/- a few db. I was originally going to go with the F12s due to how low they can dig with duals. Just making sure I am not making a mistake. I have never owned a sub outside of cheap theatre in boxes and a $300 sub from best buy I got for around $125 which has issues. So I do not know what good subs even sound like. I just wanna feel my movies.
 
#3 ·
Sealed sub should have plenty of output in your small room if -25 is the loudest you ever intend to watch movies. The reason for ported sub is to get enough output. If sealed gives all the output needed without compression, no need for the added size and cost of ported. They will both sound just as good for music


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#4 ·
Would it possible that once you factor in bass management and running the sub hot or Dynamic EQ, even at -25MV output levels of 100dB and up would be reached with the sub?

(Because I get up to 95dB peaks at -30MV... usually 90dB peaks though if I don't run things too hot).
 
#5 ·
+1. In a room only 1200 cu ft my recommendation would be for a sealed subwoofer like the F12. The FVX15 is simple to much subwoofer for a room that size. You won't get the full potential of the FVX15 in a room that size. If you want more output then go with a L22. If you want to go ported then I'd go with something no bigger than the LVX12. I have an L22 in my near field desktop setup paired with Dynaudio BM5 mkIII monitors and it sounds amazing. I also have a LVX12 in my bedroom which is kinda the same size as your room and it has plenty output to pressurize the room.
 
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#7 ·
Why do you say the FVX15 is too much sub? I am in the process of building a room with almost identical dimensions, 11x16, but no windows and only 1 door. The room will be carpeted and have acoustical treatments on the walls and ceiling. I was actually considering the FV15HP. I can only fit one sub the size of the FV15HP in the room, but I could fit two of the smaller ones. Two F12s would really be pushing my budget, but I want to make sure I can feel it. What would you suggest?
 
#6 · (Edited)
+whatever.

Since the room is sealed, my vote is for the F12, especially if you are adding another later. The small sealed sub is still a huge leap over most mains in the deep bass region, takes up less space in the room, will provide more than enough output, and the sealed design's slower rolloff takes better advantage of room gain to extend the bass response a little deeper. If the room were open to the rest of the house, the decision would be a little trickier since you may want more output. Still, in a small room like that, I would not want the subwoofers to be the focal point by going too large. Personally I'd stick with the F12's though you could consider LVX12 or L22 if you really decide you need (want) more output. In practice, if you plan to add a second down the line, a second F12 would boost the output as much as going with the lower-power 15" subs while providing smoother frequency response (depending upon placement) and deeper bass (ditto).

I had a pair of F12's in a room slightly larger than yours and they were more than enough to shake the walls. They also achieved -3 dB somewhere around 10 or 12 Hz.

Bear in mind your listening position heavily influences the bass response. Do not place the MLP dead center in the room if you can avoid it.

FWIWFM - Don
 
#8 ·
I would have a goal of 2 subs so you could attempt to smooth the response in the room. it would suck to only have 1 sub and multiple room modes/nulls that cant be smoothed out.

for home theater I would go with ported 15's, but the size and space of room may not be necessary...unless ofc you move someday and have a bigger space.
 
#11 · (Edited)
A sealed sub would work well in your room since the cabin gain starts at around 28 Hz or so and @ 14 Hz you will have 12 dB.

Therefore, I would go with L22, which is the most powerful sealed sub Rythmik has under $1000.
 
#12 ·
A sealed sub would work well in your room since you will get 12dB of room gain @ around 20 Hz or so.

Therefore, I would go with L22, which is the most powerful sealed sub Rythmik has under $1000.
+1. A pair would be OK to smooth response in the room but in terms of output + the added room gain below 20Hz of one L22, should be plenty to play at references levels even that the OP already stated that he plays at low levels (-25dB).
 
#13 ·
I don't understand why having more SPL capability is a bad thing even if it goes unused. My LV12R is good for at least 105dB at 20Hz with minimal compression and I usually listen with the sub peaking at 85dB to 90dB or less with more compressed video content (measured in REW, Z-weighted, fast response). Having that extra capability causes no harm to overall balance or SQ, and instead, having that 12 inch driver in place of a 8 or 10 inch one just makes it sound better/bigger even at -40MV to -30MV.
 
#14 ·
Not sure how 12 dB of room gain was calculated but not really my area of expertise... Usually the waves add so no more than double, 6 dB, except I suppose some sort of resonant tank could be formed, but in practice those tend to have pretty low Q.

There's technically nothing wrong with excess capability, but the room is not large, and a pair of big subs is going to look out of place without contributing anything sonically, so why bother? Plus one poster said the choice was one big or two smaller... A pair of smaller subs can help smooth the room response as well as increase output in a more cost- and space-effective system. Sealed subs have lower roll-off below their -3 dB point so can provide more boost in a small room than a larger ported model would achieve. I'd rather spend the extra money on other things I really need, or want, and keep the room a little cleaner. WAF is not an issue for me but overloading the room with big boxes is not something I appreciate. Unused capability is just that, unused, and the real and opportunity cost may not be worth it. The biggest rationale I see for larger subs than needed is if the plan is to move to a bigger place later, but it rarely hurts to have an extra sub around. Ask Enrico. ;)

IMO, YMMV, etc. - Don
 
#39 ·
Room gain in this case likely referred to the rising response in a sealed room at frequencies below the lowest resonant frequency of the room. At these frequencies the entire room is pressurized by the sub. There are no standing waves at these low frequencies because the half wave length of the frequencies is longer than the longest dimension of the room. In a perfectly rigid room there would be a 12dB per octave rising response with a sub that had a flat output to 0 Hz. Such subs are hard to find in the real world.

Basic sealed subs decline in output at 12dB per octave once their response begins to falloff at lower frequencies. In a perfect world this 12dB decline can be matched with the 12dB rising response of the room. Real rooms aren't perfectly rigid, and often have windows, and subs don't have evenly declining response to 0 Hz, so the actual gain is less than 12dB, but this is a real effect. Small rooms can have really powerful bass below the lowest resonant frequency of the room. Those with very rigid, dedicated theater rooms with no windows have likely experienced and perhaps measured this effect. Measurements using REW of my sealed, quite rigid (double separated 2 x 6 walls, double 5/8 inch drywall) media room show flat response to 10 Hz and below, once the frequency is below that of the lowest resonant frequency of the room, from simple sealed subs that are in no way capable of this response without a lot of help.
 
#15 ·
If I went with 15 now, I could still add a 12 later. Since this will be a new room, I will probably be in it for a while. What's the difference between the L22 and the F12? Why would I choose one over the other.

Here is my room layout. I can fit a big sub on either side of the center, or on the right side of the room, either in the middle or back corner of the room.
 
#17 ·
I had one sealed 15" servo sub in my room that was a little bigger than yours and I was wishing I had 2 12" sealed Rythmik's. Output is not a problem with that size room and at -25db. Headroom was also no problem as my sub could play without compression up to -10db before 22hz would top out (this sub was filtered below that).


Get the F12 or L12. I would get the dual L12's as you may not need the PEQ settings.
 
#18 ·
I get the feeling that the OP will be perfectly content with a pair of F12s in his current room/setup, but in a larger space and with possibly larger speakers (mentioned towers), that upgrade bug will start itching away and then (he said) he might either add 2 more F12's or sell the existing 2 and get a pair of ported 15s.

Considering that one F12 with shipping is within $40 of the FVX15, which has free shipping, starting out with dual ported 15s is the cheapest way to go that is more future and upgrade proof.

4 F12s is about 2x as much and selling 2 F12s is going to involve losing a significant percent of his initial investment.

Just my 2 cents.
 
#20 ·
I was thinking only of gain when the output of two subs is added in phase, effectively an anechoic assumption. One obvious case where the gain increase can appear to be much, much larger at the listening position is the case when proper positioning cancels a null at the MLP. In that case you could expect to see 20 to 40 dB of "gain" due to cancelling the null. Max output has not increased that much, of course, but by placing a source (sub) at the null to counteract it you can realize a tremendous amount of effective "gain" at that frequency. Not conventional gain as I think of it but in terms of frequency response it's there.

FWIWFM - Don

Aside: I am quite happy with my quartet of F!2's and have not experienced an "upgrade itch" in the five or seven years I have had them. Just stay away from audio fora filled with folk eager to spend your money... ;)
 
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#21 ·
I bought the f12. If I do not know what I am missing there is no need to upgrade ;-) there is a local guy who has psa xs30s (4 of them) in his home theatre and asked me to come listen. I politely refused since I do not want to be diatisfied with dual F12s haha.

He will come out and help me smooth the response once I get dual subs. I cannot wait :)
 
#30 ·
Congrats. Welcome to the Rythmik community. Here is a link to Rythmik owner laulau's zip file for his Rythmik subwoofer setup guide on the owners forum. He updates it regularly and it's a great help to many different Rythmik sub owners. It was to me. I unzipped it on my phone using Google docs but on a computer 7 -Zip or other program should work fine. Let me know if you have any questions. Our spaces are close in size and I have dual Rythmik subs as well. You're in for a treat.

http://www.avsforum.com/forum/113-s...-audio-subwoofer-thread-538.html#post25314641
 
#23 ·
Good luck with the F12. I'm interested in your thoughts after you try it out. I am still debating which one to get.
 
#24 ·
what are you debating between? I will post up what I discover and pictures of the unboxing and after its all set up.

I am very new to subs and the audio world so what I hear may be different from someone who actually knows what to listen for.

I currently have a cheap $300 JBL that I picked up at best buy for $125 to hold me off until the Rythmik got here and its sounded better than any other sub ive ever had for home theater application. It sounds muddy and not very tight so I am hoping the rythmik sound better but I am not sure what to all expect.

Eventually I am going to go dual F12's (next month) so I will report my findings than as well.
 
#40 ·
Yes, of course, I should have thought of that, thanks. Too many work days in a row...

My small'ish room helped boost my response to 7 Hz (-3 dB) with subs that have an anechoic response to 14 Hz. My walls are floating, not fixed, but I don't need any more boost down there...
 
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#46 ·
My small'ish room helped boost my response to 7 Hz (-3 dB) with subs that have an anechoic response to 14 Hz. My walls are floating, not fixed, but I don't need any more boost down there...

What is the size of your room and how many subs do you have ?



10 Hz is the new 20 Hz. :D

Kinda like 18 is the new 15, but is 21 the new 18 ? A year from now..24 would be the new 21
 
#45 ·
Depends on the music or movie and if you care for really deep bass, but considering the sub-forum we are in, the answer must be "yes" :)

The old Telarc 1812 LP (vinyl) cannon shots had fundamentals around 6 Hz. Percussive waves from drums and explosions can reach well below 10 Hz. Chances are most won't miss it, but it's nice to be able to say my system goes below 10 Hz. A lot of folk have found dipping below 20 Hz is helpful to the point that it is pretty common with quality subs.

10 Hz is the new 20 Hz. :D
 
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#43 ·
If you’ve never owned anything but a budget sub, then you are in for a real treat, especially in a room of under 1,200 cu. ft. (we are talking about significant cabin gain here). I am a bit surprised that with the Sierra 2’s joined with a Rythmik sub, you are not more interested in music. They are a terrific match for music, and obviously those two Rythmik subs you selected should be very potent in that room.
 
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