Rythmik Audio FV15HP Direct Servo subwoofer

[gadgtfreek]

It's a bigun

Amplifier 600 RMS class H patented servo controlled
Dimensions 18"(W) x 24" (H )x 24"(D) - (26" D with grille and heatsink)
Shipping Weight 120 lbs

[GOS]

Oh yeah...duh. The Rythmik. Nice.... They are wicked.

[gadgtfreek]

Then there is this one...

[MDRiggs]

Generally sealed aren't preferred for HT use because of the fact that sealed subs don't dig as deep and offer the low,low bass that movie tracks contain, however HSU claims they are good down to 15hz. Also the Epik's are sealed, don't let sealed turn you off, just pay attention to what the low frequency extension is, that is really all that matters. Besides sealed subs have tighter bass anyway, so if you get a sealed sub that can hit really low you will be happy.

A sealed subwoofer can be designed to extend as deep and play as loud as a ported sub -- the engineering tradeoffs are just somewhat different. For a given box size, driver size, and sensitivity, a ported (or passive-radiator) sub can be flat to a lower frequency, but it will roll off much faster below cutoff (24 dB/octave vs. 12 dB/octave). The area under the curve is the same, but the energy is distributed differently. And since you get about 12 dB/octave rise from room gain at very low frequencies, you may actually wind up with better effective extension from the sealed design -- just depends. Advantages of sealed include lower (sometimes much lower) distortion when driven below the tuning frequency, less variation of response with changes in voice-coil temperature (very small point), complete absence of port noise, and perhaps very subtly tighter bass on some percussive sounds. It is probably easier to design a good sealed woofer or subwoofer, with proper drivers, but you're much more locked in than with a port or passive-radiator in the mix. I think the main reasons companies favor ported subs are that they afford so much greater design flexibility (broad range of tuning options) and that it's easier to push the -3 db frequency spec down. Plus, if you're trying to do a true acoustic-suspension subwoofer the driver is relatively expensive and certainly a custom job. The bottom line is that excellent results can be achieved either way.

[CALIBER]

Sorry Riggs you still could sum that up by saying that ported subs have better low frequency extension than sealed sub's. It's just a fact!!

I was just bringing up the fact that the Epik's have allot of low frequency extension, considering they are sealed, I mean come one how many sealed subs out there have usable output down to 12hz.

[gadgtfreek]

I think thats something I like about the PB13 Ultra and FV15HP. They are both ported, dig deep, but also are very musical and have tight , accurate bass.

[CALIBER]

I think thats something I like about the PB13 Ultra and FV15HP. They are both ported, dig deep, but also are very musical and have tight , accurate bass.

Oh yeah I mean the PB13 is a legendary sub IMO. The Rythmik is right in there on performance too, but again in all shoot outs I have read the Rythmik's always gets praise for being the best sounding.

[gadgtfreek]

I think Brian Ding has a winning formulation with his subs. I've seen pics posted of plate amps and woofers lying around his house hooked up, I guess he is just a speaker junkie.

Tom V of SVS, and now PSA, said he feels the PB13U is the best thing he and Jim Farina ever did. He's also alluded that PSA may be planning some tube woofers like the PC series.

[MDRiggs]

Sorry Riggs you still could sum that up by saying that ported subs have better low frequency extension than sealed sub's. It's just a fact!!

Except it's not. In fact, if you build a sealed sub and a ported sub with the same cutoff frequency (-3 dB), which is a straightforward thing to do, the sealed sub will have better low-frequency extension because it will roll off much more slowly below cutoff. (This assumes no EQ, but sealed subs are also easier to equalize.) On the other hand, assuming same-size drivers, the sealed sub will be less efficient, physically larger, or both.

I was just bringing up the fact that the Epik's have a lot of low frequency extension, considering they are sealed, I mean come one how many sealed subs out there have usable output down to 12hz.

Probably not many, but how many ported subs do either? I doubt many more, despite their preponderance on the market. Actually, if the criterion is "usable output" (whatever that might mean at such a frequency), it's probably easier to do 12 Hz with a sealed design, because of the shallower rolloff and the good room support at such low frequencies. If, on the other hand, you're looking for flat to 30 Hz and aren't too concerned with what happens below (which is fine for most purposes), ported is going to be a pretty appealing option.

[CALIBER]

Bottom line is with the majority of commercial subs that are sealed don't dig as deep as ported, that is what I was getting at. I was mainly trying to high light the fact that because of the way commercial subs are, some people have it in there head that it is not a good idea to use a sealed sub for movies.

The only reason sealed subs are not considered to be the best for movies is because like I said, in the commercial world of subs ported subs just dig deeper. I am not arguing that you couldn't make a sealed sub have the same frequency response as a ported I am just saying it isn't that way.

[CALIBER]

On the other hand, assuming same-size drivers, the sealed sub will be less efficient, physically larger, or both.

This is exactly why most commercial ported subs get lower response, because it isn't as difficult to accomplish. With a sealed sub you will need more power and likely a bigger cab which equals more cost and less WAF.

[gadgtfreek]

As I usually do, I've gone back to the beginning of the AVS thread and started reading (2010, 6800 posts ). Im only keeping up with Brian's posts, and have a ways to go, but the guy is impressive. He's really open about his product, and since he is one of the only tech guys in his company, he uses the AVS thread as a sounding board for idea's. Makes you wish all companies were like this.

That DS1510 woofer is also pretty impressive, not as much as the SVS Ultra, but still impressive.

[gadgtfreek]

Dual F25's (15" woofers), freaking cool

[gadgtfreek]

Auralex Gramma question:

The normal Gramma is a tad smaller than the footprint of the sub, probably have 1.5" over hang on all sides. Great Gramma would be larger than the sub. I'd prefer the smaller Gramma and would assume the sub overhanging 1.5" all the way around would not matter. In case you are wondering why Gramma and not spiked, I asked them and they recommended not spiking it to my concrete slab.

[CALIBER]

Dual F25's (15" woofers), freaking cool

That is bad ass!!

[CALIBER]

Auralex Gramma question:

The normal Gramma is a tad smaller than the footprint of the sub, probably have 1.5" over hang on all sides. Great Gramma would be larger than the sub. I'd prefer the smaller Gramma and would assume the sub overhanging 1.5" all the way around would not matter. In case you are wondering why Gramma and not spiked, I asked them and they recommended not spiking it to my concrete slab.

Gosh Jason I wouldn't think that would be an issue at all. If there were I am sure evil would know, he is great with that kind of stuff. That is if you can get a hold of him.

[gadgtfreek]

Thanks caliber.

Man, Brian really is sharp. I've read about 3200 posts now, and he has one where he explains his amps and why reviewers seem to think he under rates them, with regards to how the large Panasonic caps perform he uses. He says that sometimes engineers feel they dont need as much recovery time, so they skimp out here and it costs them in the amp section. Learning a lot of stuff.

It's always neat to see so much passion in a product.

[CALIBER]

One of the reasons I was so stuck on getting my B&K av5000. Monster caps!! Caps and amperage are often overlooked IMO.

[gadgtfreek]

My eyes are now crossed, thats enough info for today lol

bed time. I hope to order the beast around 8/30, or 9/15, just depending.

[HStevens]

Sorry Riggs you still could sum that up by saying that ported subs have better low frequency extension than sealed sub's. It's just a fact!!

This has not been my experience in my room. My 12 inch ported HSU and 12 inch down firing Klipsch(very old) both sounded really good with decent extension, but were no competition for my Rythmik F12SE. The F12SE has been measured flat to 14 Hz just as Brian claimed and had great output at 12Hz. It would have easily measured lower but we did not have a test disc with signals lower than 12 Hz. The ported subs all drop off quickly at their tuning frequency, which keep in my, it's the box that is tuned.

During the many months that I spent researching to upgrade my sub, all of the sealed subs that I compared to somewhat equal spec'd ported subs, had much lower extension and most importantly, were flat doing it. Yes, some well made ported subs have tremendous output at their tuning frequency which keep in mind is the box itself. The box is tuned to the 20Hz or 15Hz etc. This is the reason that ported subs go BOOOOOM, their boxes are quite large and that is what you are hearing. I understand that this "boom" is preferred by many in the home theater environment.

In the end, you can find a ported or sealed sub to do whatever you want. It simple comes down to the preferred sound that you are after and yes they certainly sound different. I feel that if you are going for a multiple sub system that sealed is far more efficient because of their size and flat frequency response which is much easier to EQ. If you only want one, you have room and movies are mostly your thing, then a large ported well designed sub may be for you.

Lastly, Brian from Rythmik is the real deal. I called with questions several times and he answered and spoke with me at length. He has always responded to my emails and helped me Eq my room and get the F12SE optimally tuned. Furthermore, out of blue, he emailed me to ask how my set up worked out and too see if I needed further assistance or tips. Very rare in this world we live in