Controllable Fans - PWM or Rheobus or ?

So been on a silent pc and fan kick lately and read up on all sorts of controllers and fans, both for PWM (pulse width modulation) or rheobus (voltage change) controlling. Whenever someone asks about a fan or a controller there always seems to be a short list of "the best."

In order to get a handle on all these fans & controllers of varying quality, I've noticed there seems to be two categories where the "best" isn't the same small group of favorites: the more plentiful standard fans (3pin) controlled by changing the voltage (what a rheobus does) and the newer, fewer PWM fans (4pin) controlled automatically by BIOS temp sensors or by some fan controllers.

I've probably read a good majority of the relevant posts on XS but usually when people put in their :2cents: for the best, they forget what category their favorite is in and what category they're recommending for. Make sense?

Throw the CFM, RPM, static pressure, and decibel/tone noise of each fan and you can see how it get's crazy complicated. For future reference, these are all hypothetically for a water-cooled computer, since you can safely assume what works best for water cooling works equally well for air cooling/general use. Category 1 (standard 3pin) obviously has the most choices for both fans, controllers, and simpler constant voltage mods.

I guess what I hope this thread to accomplish is focusing on listing what top controllers go where and have people post their top-ranked fans and what category they go in.. I'd even imagine things like whin, e , clicking, etc might get solved by using the correct fan with the correct control category.

Category 1:
Standard 3pin fans, voltage controlled
Fans
Scythe "SLIP STREAM" 120mmx25mm (SY1225SL12H, 0-1600 RPM, 24.00 dBA, 68.54 CFM, 0.26 Amps, ~$10 USD)
Controllers
Lamptron Fan-Atic 5 Port Military Switch Baybus (0V, 5V, 12V toggle, 60W max/channel, ~$40 USD, 5.25 bay)
Lamptron High Wattage 4 Channel Rheobus - Black (FC-3) (0V-12V variable, 30W max/channel, ~$40 USD, 5.25 bay)
Lamptron High Wattage 6 Channel Rheobus - Black (FC-2) (0V-12V variable, 40W max/channel, ~$40 USD, 5.25 bay)
mCubed T-Balancer bigNG (0V-12V software-controlled, 20W max/channel, ~$100 USD)
*2 digital sensors, 4 analogue sensors, RPM signal cable, expansion available
Sunbeam Rheobus EXTREME (4V [spin@7.2] - 12V variable, 30W max/channel, ~$35 USD, 5.25 bay)
Aquaero 4.0 (0V-12V programmable-softwar, 10W max/channel [max 30W], ~$100 USD, 5.25 bay)
*"lower" power threshold
mCubed FanAMP (0V-12V, 25W constant, max 100W, $25 USD, internal)
*own power, inline with fan, 100% power @ dialed temp, minimum fan speed despite input signal*


Category 2:
PWM 4pin fans, sensor controlled
Fans
Scythe "KAMA PWM" 120mmx25mm (310-1200 RPM, negligible -24.89 dBA, 12.38~52.71 CFM)
Controllers
mCubed T-Balancer bigNG (0V-12V software-controlled, 40W max/channel, ~$100 USD)
*2 digital sensors, 4 analogue sensors, RPM signal cable, expansion available
Koolance TMS-200 (0V [spin@2.4]-12V, software-controlled, 24W max/channel [max 78W], 2A max/channel [6.5 amps/max] ~$100 USD)]
*analog control for pumps, PWM for fans (spec post); expansion available


Miscellaneous
Koolance 4-Fan Wiring Harness, 3-Pin (4 fans into 1 3pin, multiply amps)

Comparison Links
Aquero vs bigNG vs TMS200

I'd like tested or real-world results to take top priority. I'll gladly add fans/controllers as they get mentioned and change specs or real-world effects as well. I'm purposefully not making my first list all-exclusive because that'd be really hard and I'm just too lazy. When it comes to fans, please mention as much info as possible, including model number, amperage, static pressure, noise AND tone issues, fan's speciality/focus.

FYI: I'm personally researching stuff like this for a future water-cooled build. I'd really like PWM functionality, but don't want to miss out on all the voltage-rheobus stuff that has been developed more refined. Stuff that can also include pumps, flow meters, misc fans, or anything else thought off is definitely a priority.

Koolance TMS200 (0V-12V, software-controlled 24W max/channel (max 78W on all channels), ~$100 USD (have had some trouble with software)
Aquaero 4.0 (0V-12V, software-based, software independent, 10W max/channel (max 30W on all channels), ~$100 USD
There are a hundreds of controllers to list if you want to go all the way with this.

And i think that you should check martins thread. There are a lot of fans there you can list if you want. And also price you should set to ~$10 instead of $10 for example.

Quote:

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Originally Posted by Brodholm

And i think that you should check martins thread. There are a lot of fans there you can list if you want. And also price you should set to ~$10 instead of $10 for example.

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Yea, Martin's thread is absolutely golden. It'd be a better spot for more indepth info. I guess you could think of what I'm trying to do as how the fans relate to controllers and the whole package instead of just the individual fan. Both are valuable, I think.

Nice thread. I'm curious as to what everybody else uses and enjoys.

I currently use the mCubed T-balancer for my fans and temps. Unfortunately, I don't think I understand everything about it. How can this be used to control PWM fans when the ports on the bigNG are only 3 pinned?

I have always wanted to ask this. What does the mCubed/Koolance/Aquaero so expensive regarding other rheobuses like FC-2, Kaze Master, sunbeam rheobus extreme, mfc1-plus...? Does it have something to do with watercooling?

This looks very interesting
http://www.hexus.net/content/item.php?item=18520&page=6
unfortunately have no information on it and it only comes supplied with the case. Still, looks to be a switch mode design: more efficient than analogue, free from the noise of pwm. There is a controller on board and it has a pc interface and support software. I'll post back if I find out any more.

PWM fan controll sucks if you are after silence, your fans are noisier and I can post proof of this if anyone would like.

Certain fans will make a "howl" or whine due to PWM control.

With rheobus controll you need to make sur eyour initial voltage is high enough to get the fan spinning, then you can lower your voltage a bit more and get smooth silence 8)

After wieghing all options i went with the koolance TMS-200 and expansion board.

the only key thing it is lacking is direct interface to your CPU temps, but in honesty this is a software problem that may or may not be addressed. I am hoping someone can hack the software and make it happen, like really if other programs can read system onboard temps, why cant koolance?

The aquaero is very nice, but not enough juice for me.

I am running 12 140mm fans plus 2 ddc pumps. just on the cooling loop.

like wise mcubes is not enough juice for me either, unless im gonna daisy chain multiple units together, yeah forget that. Plus the software is somewhat inferior in my opinion.

Quote:

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Originally Posted by dsumanik

PWM fan controll sucks if you are after silence, your fans are noisier and I can post proof of this if anyone would like.

Certain fans will make a "howl" or whine due to PWM control.

With rheobus controll you need to make sur eyour initial voltage is high enough to get the fan spinning, then you can lower your voltage a bit more and get smooth silence 8)

After wieghing all options i went with the koolance TMS-200 and expansion board.

the only key thing it is lacking is direct interface to your CPU temps, but in honesty this is a software problem that may or may not be addressed. I am hoping someone can hack the software and make it happen, like really if other programs can read system onboard temps, why cant koolance?

The aquaero is very nice, but not enough juice for me.

I am running 12 140mm fans plus 2 ddc pumps. just on the cooling loop.

like wise mcubes is not enough juice for me either, unless im gonna daisy chain multiple units together, yeah forget that. Plus the software is somewhat inferior in my opinion.

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haven't you wondered why fans howl due to PWM control? Is it a problem mismatching a non-PWM fan, an inferior controller, or some other factor? Whining is such a subjective thing bound by circumstance it could be anything, a fluke fan or just how one particular fan brand interacts with another. I've read XS posts where the same controllers with different fans (or visa versa) have yielded different noise/tone issues. I'm interested in fleshing these out as objectively as possible.

I've also noticed on XS posts some controllers and/or fans have issues when powering up to non-full power. A few controllers have explicitly designed full power on startup and then to user-set power level to prevent this. These features are things I want to find out and note. Details like this really are what makes a controller/fan the "best" in my opinion.

P.S. Please indicate the pin number you're using and/or if they're PWM or voltage controlled just so we know the details of your perspective.

Quote:

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Originally Posted by Spoiler

I currently use the mCubed T-balancer for my fans and temps. Unfortunately, I don't think I understand everything about it. How can this be used to control PWM fans when the ports on the bigNG are only 3 pinned?

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The FanControl T-balancer or the bigNG T-balancer?

Good question though! I looked over a few product pages for both and nothing jumped out. Anyone want to chime in? I would say that the bigNG (like the TMS200) are more robust, inherently open-designed controllers that can do more than straight rheobus controllers, but do require the knowledge to setup correctly.

Quote:

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Originally Posted by liguhy

P.S. Please indicate the pin number you're using and/or if they're PWM or voltage controlled just so we know the details of your perspective.

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I have Yate Loon 2 x 120 ultra 120mm, 2 x silverstone 180mm, 12x 140mm Medium Speed Silent Case Fan - but i have noticed this phenomina for years even back when 80mm was all the rage..

Analog is superior from a noise perspective in my opinion.

•Model: D14SM-12
•Air Flow: 62 CFM
•Fan Speed: 1400 RPM
•Noise Level: 29 dBA
•Power: 2.0 watt
•Fan Size: 140x140x25 MM
•Connector: Includes a 3-pin motherboard power / RPM connector and a 4-pin standard power connector

I have both a rheobus and PWM controller, the fans are daisy chained together 6 fans running off of one fan channel.

The howl is more or less prominent at certain RPM's, usually the ones you want to be ideally running at for the combp of airflow/silence.

PWM is inferior in my opinion, the only advantage it may have is the ability to get the fan to alower RPM before stalling but I havent seen testing to verify this. Maybe this weekend i will try it out. Maybe there are newer PWM friendly fans out there now that don't howl but im die hard analog because i know it is silent in all situations..so how do you improve on that?

Why the howl ?

Basic theory of PWM control:
http://www.pcsilent.de/showInfoPage.do?name=funktionpwm

As you can see the voltage to the fan is either 0v or 12v, nothing in-between. Every time 12v is applied the fan makes a little kick which is audible to some degree dependent on the fan construction and how it is mounted. When lots of these voltage changes are applied in sequence the sound from the kicks merge into a tone with a frequency equal to the repetition rate of the voltage change aka pulse repetition frequency or prf. For fan control the prf is usually between 10Hz to 400Hz this tone is clearly audible as the howl. The easy fix for this would appear to be increasing the prf to a point beyond normal human hearing, somewhere above 20,000Hz, the problem here is such high frequencies cause heating in the fan drive electronics somewhat negating the efficiency gains pwm brings and probably shortening the useful life of the fan.

There are a couple of tricks that can be used to reduce the pwm noise:

1) Change the shape of the 12v pulse from a vertical line to a more gentile slope or curve:
http://ww1.microchip.com/downloads/e...tes/00771b.pdf

... nice idea but for best effect it needs to be optimised on a per fan basis and in my experience can actually make the fan noise worse.

2) Continually change the prf so the noise from the kicks no longer makes a constant tone. Good idea in theory, I know someone is looking into this but I've yet to try it myself.

In an ideal world I'd know enough about electronics to leverage the ideas behind switch mode power supplies to produce a variable buck or boost converter. This would be efficient, able to provide high currents and have zero pwm noise. It's on my list but as the fan header on my mb is proving quite sufficient at the moment it's not a high priority.

Ok made an interesting discovery tonight...

I finally unpacked my TMS-200 and started testing some different fan configs out using 3 controllers heres the results summary:

These 140mm yate loons mounted on my MONSTA rad are silent up to 30% (870 rpm) and "quiet" until about ~40% (1050 rpm) after that definately noticeable, but not overly intrusive until about 70%(1260 rpm) Max speed on these fans is 1440 rpm.

So mounted in a case the best combo of performance/sound ratio will be between 30 and 40% on the tms-200

Controller results

Sunbeam Rheobus - no howl, fans start to spin at about 7.2 V
Noise Isolator PWM - Very audible howl of varying pitch at any voltage below 80%, fans will spin from minimum setting.
TMS-200 - no howl, fans will spin from dead stop at 20% voltage.

I am SHOCKED, the PWM on the koolance is identical sound wise to the analog controller...zero howl, none zip, nada....I had honestly planned to use one of the the pump outputs for fan control...in fact i think its possible the post you linked above might be accidentally incorrect? It almost seems like the fan control on the TMS200 is analog man, there is seriously NO howl. I tested every single rpm setting in the software and I am very sensitive to noise..a minor buzz drives me nuts. I have avoided PWm like the plague for years cuz of this.

I just cant believe it is PWM. That said...

The TMS-200 also seems to behave like PWM from startup, beacuse if i completely stop the fan channel on the controller, and let fans spin to a dead stanstill and select 20%...they fire right up spinning at 750 rpm.

Using the analog controller i have to give it about 7.2 volts before the fans spin, then can turn it back down.

So how can this be??? This little controller has completely changed my view of PWM.. ALL the silence minus the heat dump and minimum voltage spin that analog requires?

If koolance can interface with board temps this will be the best controller on the market hands down, no competition.

can we get Dean in here to verify it is in fact PWM control? I still can't believe it, using my other PWM controller these fans HOWL liek crazy at anything less than 80% voltage, its an unnacceptable and extremely annoying buzz...it sounds like the wake up strips they cut in the highway to remind people not cross the centerline/curb..or if you have ever ridden in a big 4x4 truck with mud tires on the highway..very similar sound...drive you nuts man.

Quote:

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Originally Posted by dsumanik

...SNIP...
Sunbeam Rheobus - no howl, fans start to spin at about 7.2 V
Noise Isolator PWM - Very audible howl of varying pitch at any voltage below 80%, fans will spin from minimum setting.
TMS-200 - no howl, fans will spin from dead stop at 20% voltage
....SNIP...

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Complete and utter rubbish. There are very few fans I have that don't make noise when attached to that waste of my hard earned cash.:mad:

Quote:

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Originally Posted by ecat

Why the howl ?

Basic theory of PWM control:
http://www.pcsilent.de/showInfoPage.do?name=funktionpwm

As you can see the voltage to the fan is either 0v or 12v, nothing in-between. Every time 12v is applied the fan makes a little kick which is audible to some degree dependent on the fan construction and how it is mounted. When lots of these voltage changes are applied in sequence the sound from the kicks merge into a tone with a frequency equal to the repetition rate of the voltage change aka pulse repetition frequency or prf. For fan control the prf is usually between 10Hz to 400Hz this tone is clearly audible as the howl. The easy fix for this would appear to be increasing the prf to a point beyond normal human hearing, somewhere above 20,000Hz, the problem here is such high frequencies cause heating in the fan drive electronics somewhat negating the efficiency gains pwm brings and probably shortening the useful life of the fan.

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+1 for an explanation of the "PWM click!" This should be added to a PWM/fan/gen info sticky and/or put in a new thread itself.

Quote:

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Originally Posted by dsumanik

With rheobus controll you need to make sur eyour initial voltage is high enough to get the fan spinning, then you can lower your voltage a bit more and get smooth silence 8)

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Yea, this initial full voltage is a great, and essential, feature. I sure wished they listed how they handle voltage on startup. Correct me if I'm wrong, but I believe the TMS-200 powers at full (pump channel too) and then goes to set voltage. What about the bigNG T-balancer and/or bigNG FanAmp?

Can't speak for the FanAmp, but the BigNG unit gives full voltage for around 6-8 seconds on startup.

Thank you for your kind words.

The FanAmp is designed to reproduce the signal applied to its input while providing extra drive capability. As such if the input spins the fans to full speed the FanAmp will be faithful in its reproduction. iirc by adding a capacitor across the input you can force the FanAmp output to full during start-up, more info should be available on the mCubed site.

Quote:

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Originally Posted by ecat

Thank you for your kind words.

The FanAmp is designed to reproduce the signal applied to its input while providing extra drive capability. As such if the input spins the fans to full speed the FanAmp will be faithful in its reproduction. iirc by adding a capacitor across the input you can force the FanAmp output to full during start-up, more info should be available on the mCubed site.

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So do FanAmps start full powered then to set speed (by onboard dials or input signal)

Also, is it safe for a pump's speed to be changed by voltage? Not sure how other pump controllers or a pump's own onboard circuitry does it. If it's safe, putting a FanAmp between a D5 and analog fan controller seems pretty awesome.