Onkyo SR505 - Breathing room?

Q

Q45

Enthusiast
I recently hooked my new Onkyo SR505 and everything is working ok.
I have yet to complete the construction of my custom speakers so I'm not driving anything with the Onk yet, just running TV through it.

This thing is freaking HOT!

Now, I do have my cable box on top of the ONK, so I am assuming the gap provided by the feet of the cable box (approx. 1") is just not enough?

How much air gap should I have?
How hot should this really be getting at all, considering it's not even doing anything yet?
 
ParadigmDawg

ParadigmDawg

Audioholic Overlord
4-6'' would be ideal and dont place ANYTHING on top of it.
I recently hooked my new Onkyo SR505 and everything is working ok.
I have yet to complete the construction of my custom speakers so I'm not driving anything with the Onk yet, just running TV through it.

This thing is freaking HOT!

Now, I do have my cable box on top of the ONK, so I am assuming the gap provided by the feet of the cable box (approx. 1") is just not enough?

How much air gap should I have?
How hot should this really be getting at all, considering it's not even doing anything yet?
 
Q

Q45

Enthusiast
Alright, now I'm confused.

I moved some equip. around and now have nothing at all on top of the receiver and this thing is still pretty hot. What's up with that?

Who else has Onkyo receivers? Are these things supposed to do this?

Right now I have both the A/B speaker switches off and have been off for a couple of hours now. Nothing going through the Onk except picture control.
It's basically just on and not doing anything and it's still freakin hot.

What's going to happen when I start driving my new 300w towers?

Should I be worried?
 
B

brulaha

Audioholic
No need to worry. Just know that it runs hotter than comparable models. It's a very good receiver.
 
ParadigmDawg

ParadigmDawg

Audioholic Overlord
Dont be worried; it just runs hot. You are fine.
 
Seth=L

Seth=L

Audioholic Overlord
Onkyos have a reputation for running hot, yes, but does it affect their performance, no. If you don't like how hot it is you can put computer type fan on it.;)
 
N

Nimrod

Audioholic
I have 2" of space on my 705, got to order a fan tomorrow
 
Q

Q45

Enthusiast
Thanks for the feed.

Just a heads up for anyone possibly in a similar situation as me, note the following;

I had some 6ohm surround & center speakers from my old home entertainment system. 1 of those complete package unit deals. KOSS I think.

Anyway, I'm building my own towers and when I 1st got the Onk home the towers weren't done. So I hooked up the little 6ohm dealies just to get the stereo set-up done.

When you 1st turn on the Onk it does this self diagnostic run and check impedance on speakers hooked up to whatever channels at that very moment.
It also does a little sound check to determine where speakers are in the room and what not. Very cool.

Anyway, I got the towers done and moved them into the living room to do a trial run on the Onk before I put veneer on the cabinets, in case there's something I don't like about the sound, dig?
Well, when I did that, I moved the little 6ohm speakers over to the "B" channel, and then hooked my new towers up to the front channel.

Problem is, if the system didn't see speakers on a channel during the initial hook-up, you need to tell the Onk that you just added speakers to a channel.
Well you at least need to do that if you're adding speakers anything lower than 8ohm into the system.

At least that's what I think. I did exactly those steps and now the system sounds much better and is running very cool.

I was worried there for a moment because my new towers sounded like crap and I could not figure out why. I basically started over as if it were the 1st time I turned the system on and then everything is fine and a rockin.

Hope this helps someone.

Lay
 
Q

Q45

Enthusiast
This receiver is wierd.

Last night with the speaker switches turned off with no sound being driven by the Onk, just basically picture control, the thing was pretty hot.

But yet the other day when the wife and kids left, I drove my new towers at like 65 (near max) for like 1/2 an hour and it ran cool as can be.

What the hell?
 
jcPanny

jcPanny

Audioholic Ninja
Receiver heat

FYI,
I am using my Yamaha receiver as a pre-pro and it can still get very warm. This is normal for modern receivers.

Why did you get the Onkyo 505 to drive the customer 300 Watt towers? I hope they are 8 ohm impedance.
 
annunaki

annunaki

Moderator
Most recivers will run quite warm, some a bit warmer than others. Most current receivers are Class A/B amplifier topology. Some of the best designs out there are only going to be about 55% efficient at full power. At lower output levels, the efficiency drops down.

Efficiency on an amplifier is based upon how much of the incoming voltage from the wall socket is converted to usable output power and how much is wasted in heat and other loasses. With a Class A/B amplifier at 55% efficiency, 45% of the available power is wasted in heat and other losses.
At half power or lower, where most amplifiers are operating most of the time, efficiency is usually down around just 30%. That means 70% of the available input power is being wasted in heat and other such losses.

So, in theory, lower volumes will generate more heat, however, one is also consuming less power so it is usually about a wash. Heat output tends to remain fairly consistent between high power and low power usage. I am sure there are some exceptions to the general rule though.

If an amplifier feels hot, the heat sink is doing it's job.

Class D and other switching type amplifiers are usually in upwards of 70%-80% efficient and run very cool compared to Class A/B counterparts.
 
annunaki

annunaki

Moderator
Though quite unattractive, it should do the job pretty well.
 
64met

64met

Audioholic
Do you have any idea how loud this thing is? I have an old fan that used to be mounted on a old entertainment center... but couple things... not enough room to place it on top of my Onkyo 805 and the thing just resting on the cabinet/floor next to my receiver is its just too loud. This fan on the link looks interesting!
 
Q

Q45

Enthusiast
FYI,
I am using my Yamaha receiver as a pre-pro and it can still get very warm. This is normal for modern receivers.

Why did you get the Onkyo 505 to drive the customer 300 Watt towers? I hope they are 8 ohm impedance.
- Cuz the price was too good to pass up.
- Others in this forum stated that this receiver would have no problem driving these towers.
- And we don't normally have the luxury or need to play music that loud where we live. And I knew if it turned out to be not sufficient enough power to drive my towers, I could always add a amplifier.

Why, do you see a problem?

And yeah, they're 8ohm.
 
annunaki

annunaki

Moderator
Greg Gable said:
Vs. a pretty fan?.....;)
The fan could do without the red, that's all. ;)

Q45 said:
- Cuz the price was too good to pass up.
- Others in this forum stated that this receiver would have no problem driving these towers.
- And we don't normally have the luxury or need to play music that loud where we live. And I knew if it turned out to be not sufficient enough power to drive my towers, I could always add a amplifier.

Why, do you see a problem?

And yeah, they're 8ohm.
What is the continuous or rms power handling of the said tower speakers?

If it is 300 watts, then I highly recomment the purchase of a Behringer EP2500 as soon as funds allow.


64met said:
Do you have any idea how loud this thing is?
The fan claims to run at 33db which should be plenty quiet in a normal listening room.
 
N

Nimrod

Audioholic
The fan could do without the red, that's all. ;)

Red fans are much better then Black ones..... Really everybody know that:p

Actually I'm liking the side discharge thing, and for $20, I'll give it a try
 
Q

Q45

Enthusiast
The fan could do without the red, that's all. ;)



What is the continuous or rms power handling of the said tower speakers?

If it is 300 watts, then I highly recomment the purchase of a Behringer EP2500 as soon as funds allow.
Honestly, I am not that smart. I control the technical trades of high-rise construction projects, but don't if I'm fully qualified to calc. out RMS of a speaker.

I can tell you that in the towers we built,
The woofer had an RMS rating of 200w
The mid had an RMS rating of 55w
And the tweeter had an RMS rating of 75w

The X-over those drivers are wired to has a max. rating of 300w.

So, I don't know. Somewhere in that range, I guess?
 
Last edited by a moderator:
Q

Q45

Enthusiast
Red fans are much better then Black ones..... Really everybody know that:p
Seriously man, what a poser! You didn't know that?

That whole red fan is better than black fan thing is like so 8th grade, man!
 
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