Loud Fans

[Woodinblack]

On 05/09/2020 at 01:11, agedhorse said:

As an example, it's not uncommon to reach 100 degrees F in my area so I typically design to somewhere around 105 degrees F as the high ambient temperature condition. At these temperatures, I doubt anybody would want to either play bass or listen to bass or a band or much of anything IME.

Did an outdoor gig last year just outside a local clubhouse, it started at 2 and it was into the low mid 30s (probably not at the temp you were saying about yet). We had table umbrellas to hide under because it was so hot.

The PA went to massive fan mode just after switch on, and the case was too hot to touch, so we made a fort of cases around  to shield from direct sunlight, as well as the mixer. They both had their fans flat out sounding like an aircraft everything was flat out. My voicelive on my pedalboard died from the heat. PA survived. I barely did, I hate heat!

[agedhorse]

We do a 3 week long event (pro audio) with 6 or 7 sound systems (small up to arena size) and we design everything around 105 deg F (~40C), everything works fine for hours and hours but that's because everything is designed around these ambient conditions. As long as a designer is aware of the conditions, it's not that big of a deal. It might involve derating things a bit, but generally it's not a big deal.

[cord.scott]

I'd never play in condition that hot anyway. I just don't like fan noise lol.

[agedhorse]

15 hours ago, cord.scott said:

I'd never play in condition that hot anyway. I just don't like fan noise lol.

Designers design (or should design) for worst case conditions, different regions have different needs and a product needs to be able to be used in most habitable locations. Your choice may be different than another player's choice, therefore (most)  amps are designed for everybody's possible choices and if a fan bothers you enough, you can seek out an amp without a fan.

[cord.scott]

29 minutes ago, agedhorse said:

Designers design (or should design) for worst case conditions, different regions have different needs and a product needs to be able to be used in most habitable locations. Your choice may be different than another player's choice, therefore (most)  amps are designed for everybody's possible choices and if a fan bothers you enough, you can seek out an amp without a fan.

Sure. The amp you designed is just fine in that area. I can't hear it 1 foot away. The other one sounds like a jet. I've even contemplated trading it in for a 2nd mesa, probalby a wd-800. 

[BassmanPaul]

On 11/09/2020 at 08:28, dannybuoy said:

On my Orange Terror Bass, I've replaced the fan with a much quieter one - much less air flow than the original, I knew I was taking a risk in doing so but it turned out just fine. It has a massive heatsink and more air flow than most amps though, and larger fans can be quieter since they can get good airflow at low RPM.

HO Buoy - are you ever heading for a failure. One day you'll be playing away and your amp will go quiet - permanently!!

It's a case of it's fine until it's not!

Edited November 10, 2020 by BassmanPaul

[MOSCOWBASS]

Even the Mesa d800 fan is noticable at home....don't hear it on a gig. I've just bought a Baby Sumo (no fan) to use at home and as a backup. Feeding it with a D800+DI. I'm impressed so far, doesn't get hot in home use at least.

[thebassist]

With the Acoustic Image Clarus SL and the GSS Baby Sumo, I don't really understand why any amplifier needs a fan nowadays frankly.

Edited November 11, 2020 by thebassist

[agedhorse]

5 hours ago, thebassist said:

With the Acoustic Image Clarus SL and the GSS Baby Sumo, I don't really understand why any amplifier needs a fan nowadays frankly.

Perhaps I can help you understand why some designers choose to use a fan?

Neither of the amps you listed are rated for 2 ohm operation, and neither are rated for as much power (RMS) either.

When considering cooling strategies, my general goals (and others with similar philosophy) might choose to insure that their products are capable of operating at a higher duty cycle into a lower minimum impedance at higher ambient temperatures (I typically use 105 deg F) than other designers might choose to use. Also, the warranty offered often factor into the decision. The companies I have designed for over the years have offered longer than average, which predisposes me to a more conservative approach.

I do work hard to minimize fan noise, but a small amount will always be present.

If a fan bothers you enough, simply choose an amp without a fan and accept those compromises compared with the compromises of using a fan (noise)

[thebassist]

18 hours ago, agedhorse said:

Perhaps I can help you understand why some designers choose to use a fan?

Neither of the amps you listed are rated for 2 ohm operation, and neither are rated for as much power (RMS) either.

When considering cooling strategies, my general goals (and others with similar philosophy) might choose to insure that their products are capable of operating at a higher duty cycle into a lower minimum impedance at higher ambient temperatures (I typically use 105 deg F) than other designers might choose to use. Also, the warranty offered often factor into the decision. The companies I have designed for over the years have offered longer than average, which predisposes me to a more conservative approach.

I do work hard to minimize fan noise, but a small amount will always be present.

If a fan bothers you enough, simply choose an amp without a fan and accept those compromises compared with the compromises of using a fan (noise)

This is very useful - thanks very much for providing. A fan does bother me enough though so I'll go for an Acoustic Image Clarus SL.