Official Rythmik Audio Subwoofer thread - Page 54

That is a question that only Brian can answer, but as I remember, Brian wrote that the difference in weight between 370PEQ2 amp + DS1500 Driver and H600PEQ amp + DS1510 Driver is 12 lb.

Bye

Hey guys,

I'm trying to figure out which Rythmik sub would be best for Home Theatre (almost exclusively for HT use). There seem to be a number of different Rythmik subs and I'm not sure which one would be best. I need something that is a clear upgrade from my previous sub (HSU VTF-3 MK 2, specs: http://www.hsuresearch.com/products/vtf-3.html) Thanks in advance for the help!

I would say for HT the best would probably be http://www.rythmikaudio.com/FV15HP.html Unless if you prefer a sealed sound but overall a ported setup will probably work best.

I'm suffering through a real internal battle right now. What are you losing (besides small form factor) by going with the FV15 vs. the F15 and what are you gaining?
Also, I am a little confused by how the mutli-tune works with the FV15/FV15HP (real sub novice here.) I am assuming it comes with a port plug and by plugging one of the ports you are able to achieve tune to a lower extension at the cost of output?

I'd like this answered as well.

Ported subs are usually considered over-all a more effective solution for HT due to more output (SPL) as well as generally being more efficient (and generally more cost effective). Ported subs will usually give more output at their tuning frequency(s) versus a similar sealed sub (similar meaning same size driver and amp power). Sealed subs will generally offer more consistent levels across the subs frequency range where as a ported/tuned sub can sound great around its tune but deficient at other frequencies (some are beasts down low with hardly any mid-bass while others are great for mid-bass but fall well short down low). Here is where the variable ports (Tunes) come in to play on a multi-ported sub, you can pick your preference, you want a little more oomph down low for movies then you can tune it that way while sacrificing output at other frequencies. However when it comes right down to it the room and placement are far more important than ported vs sealed (at least in my opinion).

It's all a compromise really as each has its benefits depending upon your wants & needs .

Jason

Hi, sorry, I have a newie question. The back of the f12se has 4 RCA jacks. Does that mean it takes stereo input from two sources, or one source that does some magical 4 way thing?

Where I'm going with this:
The receiver I am purchasing has only one RCA jack for a powered subwoofer, no red/white/stereo, so the cable I need would be a single splitting into stereo? Or single and plug it into any of the jacks?

Thank you for your time.

The RCA jacks are input (from the pre-outs from your pre-amp) and output (to an amp). They would be more typically used in a 2 channel system.

In your situation you would connect the single RCA cable from your SubwooferOut to either of the L/R input RCAs. Just ignore the outputs.

"
Quote:
Originally Posted by jedovaty
Hi, sorry, I have a newie question. The back of the f12se has 4 RCA jacks. Does that mean it takes stereo input from two sources, or one source that does some magical 4 way thing?

Where I'm going with this:
The receiver I am purchasing has only one RCA jack for a powered subwoofer, no red/white/stereo, so the cable I need would be a single splitting into stereo? Or single and plug it into any of the jacks?

Thank you for your time.

The RCA jacks are input (from the pre-outs from your pre-amp) and output (to an amp). They would be more typically used in a 2 channel system.

In your situation you would connect the single RCA cable from your SubwooferOut to either of the L/R input RCAs. Just ignore the outputs."





.....or LFE output from AVR as well, right?

Some AVRs have an additional output for LFE? I don't think the one I'm looking at has it (denon 4311).

Apparently it has 11.2 pre-outs (according to the specs page on Denon's site) so you will have two Sub pre-outs to use, pick one.

Rare to nonexistant. Some of the Denon 58xx series flagship models had 3 subwoofer outputs: left, right, LFE. The latter was silent unless the source material had a .1 channel.
You're right, it doesn't. It has 2 subwoofer outputs (combined LFE + redirected bass), but no dedicate LFE output like the older Denon flagships.

Great, so with two f12se's (enroute!), I will get two RCA cables. Would it be better to get a split for each cable to plug into both L and R input of each sub, or just randomly choose L/R with the single cable?

One of the cable runs will be about 30ft. I hope the monoprice cables are good for this?

So would it be fair to compare a FV15 with a PB13 Ultra in terms of frequency response, low-end extension, SPL and overall sound quality?

Keep in mind that the Denon 4311 does something unique during auto-setup to take advantage of dual subs. It calibrates (sets levels and distances) for each sub independently, but does room correction (equalizing) for the interaction of both subs together (since that's what you'll be hearing anyway).
You'll get double the signal if you use the L+R inputs on the sub compared to using L or R. But it won't be better or louder (will end up being calibrated to the same level).
That's what I use.

I know these are overdue.

First, two port configuration with rumble filter set to ON. This is the position that we "ask" the customers to set for 2ports, tuned to 18hz. It is not an option. Here is the result with low pass filter (LPF) switch at AVR/12:



The phase shift is a bit high compared to a sealed sub. That is the trade-off between sealed and vented. For the least phase shift mode, we have 1 port tuning:




The above is the 1 port tuned to 12hz, same as the condition as 2port. But here we ask the customer to set the rumble filter to "OFF". The extension is not quite 12hz. The purpose of this configuration is to reduce as much phase shift as possible. As a result, I let it roll off more naturally. Notice the phase shift at 20hz is 180 degrees. Just 90 degrees higher than our sealed subs. Note that our sealed sub at 14hz/high damping has one of the lowest phase shift and group delay among all subs tested by Ilkka.

Rumble filter off position has a build-in FR contouring circuit such that the two FR (18hz and 12hz tune) will line up exactly, so customers do not need to run Audyssey or other room EQ program again when switching between the two as shown next.



As long as the customer keep the volume and extension filter setting the same, just 1) plug (or uplug) 1 of the port, 2) flip the rumble filter to the correct position, and the two FR will overlay exactly like above.

For those who believe extension up to 200hz is necessary to get good HT sound, we have LFE mode in selected models and this is FR of 2port in that mode.


We would recommend against using this because the port resonance of vented sub will be in the frequency range between 100hz and 200hz as seen in the above plot. We want to attenuate that as much as possible, not as little as possible. In addition, this type of port resonance is not unique to our vented subs, it is in fact in very vented sub because of the length of port(s) required by such low tuned frequency.

Here is the FV12 single tune -- 20hz. It is -4db at 20hz. There will be no LFE option. For most applcaition this is sufficient.




FV12 should be available shortly before Xmas.

I have using 14hz low damping to get visually the max FR flatness setting (I don't need this is a Butterworth setting, it is definitely more like Chebychev with acceptable ripple). The high damping would have a more gradually attenuation and it would take out some of the ringing. In other words, we use low damping as the ceiling FR that we can accept without adding boominess that is common to vented subs, and all the other lower ringing setting just naturally fall into their places.

Here is the photo, an E15 bamboo.

Does anyone know if Rythmik has ever offered specials around the holidays? Just wondering if now is a stupid time to buy or if delayed gratification might save me a few bucks.

That would match my natural bamboo Sierra-1's, stands, and floors perfectly!!

My F15 creeps on the hardwood floor during high output sessions. It has gone so far as to pull the speaker wire molding off of the wall. The box is currently sitting directly on the floor. What can I mount it on to keep it stationary?

I haven't had this problem and I have my sub on furniture sliders.

If I had creeping problems, I would try some rubber feet.

Hi, Brian. It looks great, although I think I'll stick with piano black. At least you've finally posted a high-quality pic of an E15.

Wow -- looks like they did a fantastic job! I might want that unit, Brian

Strange occurrence today...

WotW @ about 21:45 (during pod emergence) has some sub-sonics that put both of my 12" Rythmiks into protect at the same time, they are not hot at all, not even warm. This happens with my AVR at -12 so not really pushing them but the BFD does show a RED clip at that scene for a very brief moment (my understanding is this was ok but I guess the Rythmik amps are more sensitive to this, none of my other subs shut off during this scene). This is very odd because I have pushed these subs at reference with plenty of material but never had this happen. This scene just must be too low and too strong, although I played HTTYD with no problems and that has been reported to have content down to 2-3 Hz. The subs are calibrated almost perfectly flat and sound phenomenal no matter what I throw at them, these are using the older 300w servo amps. The system is calibrated about as perfect as it can be in my problematic room and I spent hours on the subs to get them 'just right'. Any idea's other than turn it down or lower the AVR LFE out, hehe. I have pushed these to +4 with some other material (BASS heavy music) and never had even one of them shut off (even when they were pretty warm).

Even the mighty lightning strikes don't exhibit this behavior at reference level and they send the RED light blinking on the BFD as well.

Anybody else had this happen?

Jason

WotW = "War of the Worlds" SE DVD with the DTS 5.1 track (this is not a full bit rate DTS track so I am wondering if maybe the blu ray of WotW would clean this up and prevent it... a reach I know )
HTTYD = "How to Train Your Dragon" Blu Ray with TrueHD 5.1 track

WotW played via PowerDVD 10 on my HTPC

The amp has several protection modes that can be the source of trigger: 1) over-current with SOA curve. SOA is safe operation area. It is a way ensure output transistors are not fried during high output current. SOA curve is frequency dependent. In short, the amp has almost no overcurrent protection at high frequency to increasing sensitive overcurrent protection and the most sensitive is at DC (limit to 3A each transistor for a total of 6A). So this is frequency dependent, 2) DC protection. There is no filter that passes DC and filter out all AC components. Just like there is no filter that will keep all AC components and remove just DC part. The attenuation is gradual. In short, the protection will trigger if the frequency is very low such as 1hz, 2hz, ... If the protection does not happen again WHEN YOU TURN ON RUMBLE FILTER or reduce bass extension, then you can be sure that it is ultra low frequency induced. Another concept that is important is prolonged clipping any where in the amplification chain actually introduce a DC component into the signal and that can become the source of DC protection.

found what I was asking on the website!

I see, thank you for the insight Brian, very much appreciated. I may just have to try another calibration session and see what I come up with .

Jason

Jason, I think I missed one important sentence in my previous post which I corrected now. Try turn on rumble filter or reduce the extension. Our A370PEQ2 amp does have a rumble filter, but A300 does not. If you can turn on rumble filter for instance on BFD or AVR and the protection is gone, then you know you have a low frequency induced protection.