Official Rythmik Audio Subwoofer thread - Page 266

Originally Posted by TheLaw612 

Brian - any new updates on the redesigned FV12?

Originally Posted by Follz20 

I would implore people to not underestimate the effect of being out-of-phase with the mains has on the impact of the bass.. not to mention that auto-calibrations are not always optimal.

Originally Posted by dstew100 

Hmmm, I may have misinterpreted "I ran Audessey MultEQ. It set my front speakers to large and turned on a setting called double bass. I crossed them over at 80 instead. I tweaked the levels just slightly with a db meter (Audessey got pretty close) and ran the sub about 3 db hotter than the rest."

Definitely respond to Brian / Rythmik reply. They are smarter than me. What are your mains and what is your AVR? I stand by the Klipsh doesn't hold a candle to your sub though.

Originally Posted by Skerlnik 

I, also, have experienced the "lack of output" when you first fire up the sub. After talking to Brian, I am convinced it was just due to the sub not being broken in yet, and the spider/surround needing some exercise. After a day or two, the sub started sounding much better!

Originally Posted by Follz20 

I would implore people to not underestimate the effect of being out-of-phase with the mains has on the impact of the bass.. not to mention that auto-calibrations are not always optimal.

Originally Posted by woody777 

Brian gave me a call today -- just from this thread and a PM (from him). I didn't have to "officially" even contact Rythmik. Despite issues with my sub, customer service so far has been top notch and I'm sure the issue will be resolved.

Originally Posted by DonH50 

@woody777 -- Have you tried a different cable from AVR to sub? is it a humming sound (that may be caused by a ground loop)? A very loud buzz and noise could be a bad cable (among other things).

Originally Posted by jay500000 

I know this may be a Stupid question but I have a question regarding fv15hp mcaac sets the db to -0.5 and the volume on the sub is 3 clicks above 80 I run my sub 6 db hot which is great for movies but not so much for music I listen to a lot of rap is it safe to turn the volume on the sub to 3 a clock or is that dangerous basically I would like to know how loud I can play the sub at?

Originally Posted by pyronious 

Hey folks, I'd like to get your opinion on placing a Rythmik F15HP on a hardwood floor. I've heard several people recommend some kind of vibration isolation to decouple the subwoofer from the floor. Of those, there's the "rubber feet" camp, the "isolater pad" camp, and the "spikes on coins" camp. Any thoughts on one over the other?

For rubber feet, I saw these "bench cookies" mentioned and they seem affordable but their vibration isolation properties are unknown as they are not designed for this purpose.

For a platform, the most common recommendation is the Auralex subdude. However, the base of the F15 is 19"x20" and the Subdude is 15"x15". Is it OK (or perhaps even beneficial) to have the sub hang off the edge of the isolation platform, or should I upgrade to the Great Gramma, which is 19"x30"?

Lastly I see a lot of people just using speaker spikes resting on a coin (like a quarter). Thoughts?

Thanks!

Originally Posted by XStanleyX 

I asked for rubber feet when I ordered my  fv15hp. It's passing thru Colorado right now and will be here on Monday. I hope!

Originally Posted by pyronious 

Hey folks, I'd like to get your opinion on placing a Rythmik F15HP on a hardwood floor. I've heard several people recommend some kind of vibration isolation to decouple the subwoofer from the floor. Of those, there's the "rubber feet" camp, the "isolater pad" camp, and the "spikes on coins" camp. Any thoughts on one over the other?

For rubber feet, I saw these "bench cookies" mentioned and they seem affordable but their vibration isolation properties are unknown as they are not designed for this purpose.

For a platform, the most common recommendation is the Auralex subdude. However, the base of the F15 is 19"x20" and the Subdude is 15"x15". Is it OK (or perhaps even beneficial) to have the sub hang off the edge of the isolation platform, or should I upgrade to the Great Gramma, which is 19"x30"?

Lastly I see a lot of people just using speaker spikes resting on a coin (like a quarter). Thoughts?

Thanks!

Originally Posted by K5/SS 


Nice Stanley. My XPA-5 gets here Monday also. We will be busy little bees:)

Originally Posted by pyronious 

Hey folks, I'd like to get your opinion on placing a Rythmik F15HP on a hardwood floor. I've heard several people recommend some kind of vibration isolation to decouple the subwoofer from the floor. Of those, there's the "rubber feet" camp, the "isolater pad" camp, and the "spikes on coins" camp. Any thoughts on one over the other?

For rubber feet, I saw these "bench cookies" mentioned and they seem affordable but their vibration isolation properties are unknown as they are not designed for this purpose.

For a platform, the most common recommendation is the Auralex subdude. However, the base of the F15 is 19"x20" and the Subdude is 15"x15". Is it OK (or perhaps even beneficial) to have the sub hang off the edge of the isolation platform, or should I upgrade to the Great Gramma, which is 19"x30"?

Lastly I see a lot of people just using speaker spikes resting on a coin (like a quarter). Thoughts?

Thanks!

Originally Posted by XStanleyX 

This is what Bill Fitzmaurice has recommended: http://www.amazon.com/Genuine-Joe-Anti-Fatigue-Beveled-3-Feet/dp/B000EFK9KM/ref=sr_1_12?s=home-garden&ie=UTF8&qid=1358282258&sr=1-12&keywords=comfort+mats

Inexpensive and effective.

Originally Posted by Bill Fitzmaurice 

It's all you need, assuming you need anything. Next to high priced cables and power conditioners isolation pads and spikes are the biggest scams in audio. The following quoted claims are taken straight from the websites of manufacturers of these devices:

The Isolation Claim: ‘Its purpose is to prevent sound from transmitting through your subwoofer to surrounding surfaces. Subwoofers create big vibrations (low frequencies) that you can feel in the floor and in objects placed nearby. When the source of the vibrations is coupled directly to the floor it causes these objects to vibrate or resonate…’

The Truth: The source of these vibrations is the movement of the driver cone. The claim would only be true if you coupled the driver cone to the floor. If the cabinet panels vibrate enough to cause the floor to vibrate the speaker is defective.

The Decoupling Claim: ‘Isolators for your speakers…will decouple your speakers from the surface they rest upon, resulting in a more pure, accurate tone. Low frequencies will be projected and will no longer lack the definition you desire. Mid and high frequencies will be crisp and intelligible. Rattles and resonances will be a thing of the past.’

The Spike Claim: ‘By rigidly coupling a loudspeaker enclosure to a floor by means of a spiking system, it is possible to dramatically improve clarity, stereo imaging and bass response. This is very apparent with subwoofer systems.’

The Quandary: These sources claim the same benefits from coupling and from decoupling. Who’s telling the truth?

The Truth: Both are lying. Isolation and coupling makes no difference. To test this I measured the response of my THT and my David with the test mic in the room, in the next room, and in the room below, with the cabinet sitting on the carpeted floor, on four inches of high density acoustic foam, on rubber feet and on spikes. I’d post the measured results for each set of comparisons, but there would be no point. In each case the measured responses of the four options were identical.
Note that this was on a carpeted floor. There may be some slight benefits to isolation devices or rubber feet on a bare floor, or on a bare shelf or stand. But you never want a bare floor, it’s an acoustical nightmare. If you only have area rugs in your listening room stick a piece of felt carpet padding, a carpet scrap or rubber feet under your speaker. If you're using bookshelves on a bare shelf or stand small rubber feet or felt pads are all you need to prevent spurious vibrations.

The Endorser Claim: ‘I tried them and they work, I know what I’m hearing!’

The Truth: The first thing you learn in an acoustical engineering course is that you don’t know what you’re hearing. If you did you’d be able to listen to a speaker, take pencil and graph paper in hand, and draw a frequency response chart, THD chart and waterfall plot, all with 1/24 octave resolution and 1/10dB accuracy. Our ears just aren’t that good, not by a very wide margin. But our imagination works very well, and that clouds our audio judgment, leading to placebo effect. In short, if you think something will make a difference in the sound, it will.

For an in depth examination of why we really don’t know what we’re hearing check out this video:
http://www.youtube.com/watch?v=BYTlN6wjcvQ

Originally Posted by DonH50 


The only time I have measured the impact of feet on speakers was ages ago at a store I worked at in the 1980's. The step/impulse response was better (on a 'scope, using a measurement microphone and preamp) with spikes through the carpet to the concrete floor beneath than with the speakers (Magnepan and B&W IIRC) just sitting on the carpet.

Originally Posted by DonH50 

I like rubber feet because they keep the sub from moving on the floor since most cabinets do vibrate a little in response to cone movement. They also protect the cabinet from a spill on the floor. .

Originally Posted by mikepos 

I'm undecided between subs and number of subs. I play moslty home theater but also music and am fussy on music reproduction. My room is 14 x 18 x 8 ft and my mains are PSB stratus gold fed by oppo95 direct to Bryston 3BST (very SPL capable combo), with Lexicon (bryston) 5ch for surround channels, no pre/pro. I play very loud music and movies and need good output. My current sub is corner loaded Hsu vtf-3mk2 and it's output hasn't failed but I have turned down the volume in load bass heavy scenes to be safe, I feel I'm pushing the spl limit. My bass response is quite uneven and I'm considering 2 subs to help fill nulls (I sit near one - length wise in room mains are 3' off front wall and I sit about 1/3 off rear wall, gives best music this way). I find the Hsu a bit boomy currently but much trial hasn;t found an even spot for it including moving seat a bit.
For single sub I'm drawn to the FV15HP but am concerned I'll still need 2 to even out the bass and adding a second is more than I want to pay. So I'm considering trying the F15 first then adding a second if needed but I'm concerned about volume for those (would probably go middle of front and back walls if I got two). My room is dedicated and sub size is not important. I hope the F15 or FV15HP will help me even out bass with the PEQ and would like to start with one unit.
I live in Canada near border and would ship to Maine but I don't want to be hit with shipping for the 30 day trial... can I expect to be happy and have headroom for the F15 (370PEQ)?
Also, is there any sound or performance difference if saving $100 with the 550PEQ3 on the FV15HP? And if I got this now and added a 2nd FV15HP with the 600PEQ3 (say no 550 left) would there be any issue matching them? I've seen a few amp issues posted lately, are these the 550 or 600W amps - please post if you're one of those with amp issues.

Lastly, can anyone compare the Hsu vtf3mk2 (same as current vtf2 but with 50W more amp) compared with the F15 370PEQ3 for SPL?
thanks.

Originally Posted by Bill Fitzmaurice 

Next to high priced cables and power conditioners isolation pads and spikes are the biggest scams in audio. The following quoted claims are taken straight from the websites of manufacturers of these devices:

Originally Posted by Bill Fitzmaurice 


The Isolation Claim: ‘Its purpose is to prevent sound from transmitting through your subwoofer to surrounding surfaces. Subwoofers create big vibrations (low frequencies) that you can feel in the floor and in objects placed nearby. When the source of the vibrations is coupled directly to the floor it causes these objects to vibrate or resonate…’

The Truth: The source of these vibrations is the movement of the driver cone. The claim would only be true if you coupled the driver cone to the floor. If the cabinet panels vibrate enough to cause the floor to vibrate the speaker is defective.