Official Rythmik Audio Subwoofer thread - Page 247

Look like you already in bass heaven . Btw , why you turn off Audyssey when watching movie ?

Audyssey was switched off at that time because I just added 2 rear surround speakers to jump from 5.2 to 7.2 setup. Didn't have much time to do the full Audyssey calibration setup. I set the level and distance of the surrounds manually and straight away watched a few movies.

After Audyssey setup, I feel that the sound is much better. with Dynamic EQ turned on and Dynamic Volume turned off.
Edited by Skylinestar - 11/25/12 at 10:28pm

I already have Monoprice now for my HDMI, and sub cable. I was just wondering any difference and for the lengh if one would be better than the other. I was leaning towards the Monoprice anyway since there is a appox. $30. difference! Thanks for the reply!

Jeff

I would love to have one of the larger and more powerful Rythmik's. What I label snake oil is the use of "fast" and "slow" when describing a sub. A "fast" sub would be a midrange. I would expect a Rythmik sub with its servo technology to have lower distortion but not be "faster" or "slower than non-servo ones." Of course subs sound different but to say that its because its ported rather than sealed is contrary to what I've read and experienced. A properly tuned and sized vented sub will go lower, louder and cleaner than a sealed sub. There is a vocabulary that is used with snake oil and some of what I've read in this thread is snake oil and often used even by Rythmik himself.
Edited by Theresa - 11/25/12 at 7:36am

For a subwoofer "fast" refers to its ability to respond quickly without excessive overshoot and then ringing afterwords. Servos do that very well; with others you are depending upon the amplifier's control alone, along with wires and such. Servo allows dynamic control through the feedback circuit.

I have measured and heard the difference and that is why I went with servo (ever since I first designed my own back in the early 80's). Measuring the step or impulse response it is easy to see the difference. IME the decay (ringing) is actually the problem with most subs as that blends into the next attack, producing what is often described as "muddy" bass.

Brian and the rest of us use popular terms, but I believe in this we are in agreement. I agree many people mis-use the terminology, and that is assuming I even know what the heck they mean (liquid sound? dynamic midrange? etc.)

Not sure why the rant on vented vs. ported; it is a design trade, and a ported sub trades efficiency for extension below the port tuning frequency (since the response falls off more quickly below the port frequency). "Properly desiged" means what? Equal volume, equal LF response, what? I do not think either design is particulrly sonically "better" although theoretically sealed should damped the cone better; that matches my measurements and those done by reviewers, the AES, etc. I would not say a vented design would go "lower, louder, cleaner" than a sealed design, nor that a sealed design sounds better in general especially when servos are involved, but whatever.

One glaring observation or item I learned reading Archaea's Kansas City Blind Subwoofer Shootout 2012, blind sub testing results and subsequent posts were people could not accurately identify ported versus sealed subs based on sound quality. And some of these listeners voters have listened to many subs, have some pretty good listening ears. Pretty much shoots ANY preconceived notions to hell, mine included. And this is not the first time they executed blind sub testing. Pretty conclusive data really.

Go read for yourself if you must.

http://www.avsforum.com/t/1387178/archaeas-kansas-city-blind-subwoofer-shootout-2012

Looking to get an F15HP SE. Is there any reason to buy directly from Rythmik versus Ascend or vice versa besides money going directly to Rythmik?

^^
No. The difference is you have to pay tax if you live in CA or TX. I live in TX so i ordered mine from Ascend to save tax. They are all shipped from Austin TX.

Fast and slow, to the first order, is the time domain issue. But if you understand the Q value, you know there are multiple Q values. For instance, the "slow" sub is often associated with those with high Q value (with a lot of ringing). But you can EQ it to become a low Q frequency response. Does that completely address the problem? Not exactly. Whenever there is nonlinearity or external disturbance in the system, the system's higher Q (slower intrinsic response) will show up. Some may mistake that as slow bass to the second order effect even when all the other spec says two speakers in comparison has the same Q in time domain response.
Edited by Rythmik - 12/2/12 at 3:01pm

Brian, could you please comment on my issue posted here (post #7370) ? I have also PM'ed you.

A lot of test tones are warble tones. And warble tones do sound like flapping. Why do we use warble tone instead of pure sine tone? Because it tries to address room mode problem. You may have heard the term spread spectrum. It is a technique to spread the signal over a bandwidth to avoid fixed-path cancellation and other problems in cell phone signal transmission. So is the test tone we used to circumvent the problem of room modes. It is actually a signal with a designated bandwidth so that the measurement won't fall into a trap that the tone we use perfectly hit a null point, resulting a reading that is so sensitive to how you hold the microphone. It is also a concept of "averaging". By speading the frequency components, what the microphone reads is the average of FR in a frequency band window. A lot of times the window is designated as 1/3 oct which is not a coincidence.
Edited by Rythmik - 11/26/12 at 8:26am

Nice rebuttal Senor Rythmik......sometimes ignorance IS NOT bliss

Is it OK to stack an FV15HP on top of another FV15HP? Can the cabinet handle the weight?

One should have such dilemmas in life?

Brian,

I was wondering if you have any numbers handy for power consumption of the A370 vs H550/H600 amps? I've seen some numbers in this thread, but not enough to understand if there's any real difference. Specifically what I'm curious about is how they compare in the following cases:

• POWER=ON but with no signal
• POWER=AUTO but with no signal (AKA standby)
• max output (obviously different between them, but I'm assuming I can use this to gauge their relative efficiency with equal output, and that this is a more likely number for you to already have for each)

Thanks,
-- Dave

I'll be shifting the setup to another room with smaller space due to WAF...hence the need to stack the subs. Can the cabinet handle the weight of another FV15HP?

One would think so but best answered by Brian (Rythmik). So she's kicking ya out the main LR?

For A370

• POWER=ON but with no signal => 10W
• POWER=AUTO but with no signal (AKA standby) => 7W
• max output (obviously different between them, but I'm assuming I can use this to gauge their relative efficiency with equal output, and that this is a more likely number for you to already have for each) => 600W

For H600/H550

• POWER=ON but with no signal => 12W
• POWER=AUTO but with no signal (AKA standby) => 8W
• max output (obviously different between them, but I'm assuming I can use this to gauge their relative efficiency with equal output, and that this is a more likely number for you to already have for each) => 850W

Yes. you can structure wise. But if you make it tall, the center of gravity will be high and that is not good.

I knew a guy with his dual FV15HP stacked. But, on its side. Both at the front corner of the room and a F15HP right at the back of LP. Room size is about 14' x 22'

Do you mean the sub will fall off on its own when the bass hit?

Thanks Brian! Looks like there isn't much practical difference under most scenarios (which I suspected, but it's good to know for sure).

Another question for you: Would an F15 with a DS1505 be an option? If so, how much extra would that cost (both in product and shipping) over a regular F15? And would that cause any delay in shipping (I'm looking to order in the next day or two, if it makes a difference)?

Hello all,
I have a F12SE, and I have a question if I have my sub set to 14hz, and high damping should I only have my rumble filter set to on if I am watching movies at ref level? I live in an apt and I can only have my volume @ -28 at the loudest. FYI, my receiver has the LFE ch set to flat.

You shouldn't need the rumble filter. In The Olden Days of Yore it was to limit the nasty LF excursions from turntables (warped records, circular grooved thingies rarely seen these days). Nowadays you should not need it, especially if you do not listen loudly. Leave the limiter on and that will protect the sub, but I bet you will never engage it.

Hello Rythmik,
My velodyne hgs 15 was broken (amplifier and cabinet case is good, driver break down) so can i replacement 15' Rythmik Driver for HGS15 Driver (Servo Driver).
HGS15 have 2-wire connection from the amplifier signal to the driver, also four small wires connected to the servo (4 wires mean: Feedback signal)
Can you give me some advice?

Thanks.

Call Velodyne. The feedback they used was based upon an accelerometer on the driver, not the same as the Rythmik scheme IIRC. There are also places that rebuild speakers; Google it. Oh, to keep Rythmik content, just buy a new Rythmik and you'll be happier.

+1

DS1505 is possible. The upgrade is $30. Shipping is same. Which F15 finish are you interested? I have a bit of backlog here. And the relief will arrive on Friday.

Thanks, i called Velodyne but they have not this driver (discontinuel HGS seri).
I live in Vietnam so there is no serivce rebuild driver. I only buy aother Driver for replacement.

Thanks for your reply!