Receivers coming with no fan ?

[ArxFatalis]

I recently purchased a new marantz high current receiver ( sr 4500) and although I have no complains with its peformance I was wondering why the lack of a fan ? My other electronic equipment like my X BOX and gamecube have their respective fans to cool things down.

Receivers are supposed to generate lots of heat so why don´t they have at least one fan ? The reason of my question is because if I put the receiver to - 5 getting close to 0 , things get really, really hot. My speakers are MTX tower loudspeakers rated at max. 150 watts RMS. Am I doing wrong by matching an 80 Watts high current receiver to these hungry power speakers?

Thanks for your replies.

 

[j_garcia]

Fans are generally noisy, and you don't really want that in your audio gear. If you are running your receiver at that level, it's time for a more powerful receiver or an external amp for the mains. You are running at basically 100% gain with no room for dynamic peaks, which means you are likely about >< that close to clipping the amp section damaging your speakers.

150w is a maximum rating, not a requirement. Your speakers don't NEED 150w to reproduce sound, however if you are running them set to large and they have a large driver to produce bass, this is one main reason why your receiver is getting hot. As well as the fact that to achieve the SPL that you are looking for, you are basically running that receiver within an inch of it's life. Your receiver IS underpowered for the way you are using it, though not exactly for the reason that you thought.

I have a fairly large room and I cannot turn my system to -5 without it being very uncomfortable to listen to.

 

[WndrBr3d]

This has been discussed on this forum before.

The rule has been that normal heat generated from a receiver will not cause any loss in sound quality or performance, because the heat generated is within the operational limits of the unit.

The majority of heat generated by receivers is from the transistors in the amp. These are bolted to the giant (usually aluminum or steel) heat sinks in the receiver. Transistors, because they're a simple device, can operate at very high temperatures without ill effect. For example, the junction temperature of a common amp transistor that you can pick up from radio shack is around 150 degrees Celsius (302 degrees Fahrenheit). This is why our receivers put out so much heat.

Most units are designed using convection cooling. The heat sink fins are lined up vertically, which causes the hot air to rise out the top of your receiver pulling in cool air from the bottom and over the heat sink fins. This is why it is never recommended to place your receiver on top of any device that might generate -any- heat.

Most fans that ARE in receivers are used to actively cool more heat sensitive components like DSPs and other ICs. These devices, because their logic gates are so small (we're talking microns) heat can cause a gate to not toggle or even burn up. As you could imagine, this would not make the software running on that platform very stable, so most modern "high power" IC's (Genesis FLI-23xxx, Computer Processors, GPU's) require active cooling.

Luckily, the majority of receivers incorporate audio processors and DSPs that are smaller and have a low level of power loss, making them generate less heat. Because of this, they're able to maintain full operation while only being passively cooled.

I also completely agree with j_garcia's reply, I was only expanding on your question of why most receivers DON'T use active cooling, while other home theatre devices do.

 

[j_garcia]

Forgot to ask, do you have a powered sub? If not, that can help you out some because it will offload the heavy work to the sub's amp, allowing more headroom for your receiver to work with because it is not trying to reproduce the lower frequencies which require the most power to reproduce.

 

[ArxFatalis]

Thanks for the response , very informative. I have another question:

I will have a party in a couple of days and want to shake the whole neighborhood. If my marantz receiver gets pretty hot at 0 , does this mean I will not be able to use it at + 18 ? Will I damage the receiver or the speakers?

Keep in mind these are EFFICIENT 92 db tower speakers rated at 150-200 watts RMS. Being efficient does it make it more safe while pairing it up with an 80 watts HIGH CURRENT receiver?

Am I supposed to turn the BASS and TREBLE at 0 or even -8 to avoid ditortion or even damage?

What settings do you guys use with bass and treble when hearing music at 0 or + 10 levels ?

Many questions , I know ,but ignorant and fool is the one who never asks!

 

[jaxvon]

I would never turn a receiver to the max volume setting (someone did that here with some polks and cooked his speakers). I would keep it at 0 or not too much above. If it gets really toasty when you play it now, pick up a small fan to put on top, like a 120mm one.

 

[j_garcia]

When the receiver runs out of current to adequately drive the speaker, the speakers are generally what fry, usually the tweeters. +18 would probably not be a great idea regardless of sensitivity. A fan isn't going to help you in terms of not having enough power either, for what you are trying to do. It's going to help keep the receiver cool, but it at 100+% of operation, something is going to give sooner or later (probably sooner).

 

[Buckeyefan 1]

If you are going to throw a party and want to shake your neighborhood, then I would suggest using a friends equipment. Parties are usually what kills equipment. When you're not looking, someone will kick up the bass and treble, and crank the volume (always happens with AC/DC). The first things that go are the tweeters in the towers due to excessive distortion (I recommend horn tweeters for parties). After awhile, your amp overheats, and goes into protection mode. The party soon dies.

If you want to play your system at party levels, leave the tone control levels flat (0), and turn up your system until it is barely too loud, then take it down two notches. You'll need to feel the top of the receiver every so often to make sure you can't fry an egg on it. Keep the receiver ventilated. No cd player on top of it. Do not put it in an enclosed cabinet.

I'd even recommend using a small piece of masking tape on the front of the receiver where you want the volume to stay. That way, when everyone is hammered, they know what the limit is. Finally, get those MTX towers in corners, and keep them on the floor. You'll maximize bass for more efficiency. If you are running the speakers more than 25 feet from the receiver, use a heavier gauge speaker wire - say at least 14ga. The less resistance, the better. You should have no issues with your new receiver or speakers. Drink one for me.

 

[ArxFatalis]

So what is the purpose of manufacturers having volume settings up to + 18 if it is dangerous to both speakers and receiver to have it already at 0 or +3 ?

Also, when using the settings at 0 , the speakers sound like the bass is gonna blow and the speaker is gonna explode , so buying a let´s say 150 watt amplfier , wouldn´t this damage the speakers? My receiver has preamps so I´m seriously thinking of buying a separate amp.

 

[j_garcia]

When it's at zero and running out of current, that's why it sounds like crap. With a solid 150w at the same volume, odds are, it won't sound as bad. It's too little power that typically causes problems, not too much.