Can I add a fan to my receiver?

[Buckeyefan 1]

Output impedance equivalency, don't you know? Like an output transformer. Or, like when Carver adds a resistor to the output to make it sound like a tube amp, altered frequency response.

Sound like a tube amp? What's a tube amp sound like?

 

[pefat]

Originally Posted by mtrycrafts
Fistly, before anything, remove those resistors, they affect the frequency response, like having a tube amp with a high output impedance, and affects damping.

But without the added resistor which I added to each of my front speaker I don’t have an equivalency of impedance between the speakers and the amp so does not it influence the sound?
My amp is intended for 6 ohm and my speakers are 4 ohm so I added 2 ohms to each speaker.
Also I am sorry but I didn’t understand the damping link that you gave me, can I reach you through an icq number or messenger, if so what is your number?

 

[MacManNM]

Output impedance equivalency, don't you know? Like an output transformer. Or, like when Carver adds a resistor to the output to make it sound like a tube amp, altered frequency response.

Really????? I didn't realize that a carbon resistor with basically no Le, affects the FR output of a unit that has, in reality, an infinitely low Z. Is this audible? A 3 db variation in FR from a little 2 ohm resistor, wow!

 

[mtrycrafts]

Really????? I didn't realize that a carbon resistor with basically no Le, affects the FR output of a unit that has, in reality, an infinitely low Z. Is this audible? A 3 db variation in FR from a little 2 ohm resistor, wow!

It doesn't take a 3dB variation, does it? How does Carver demonstrate his amps with that output resistor of only 1 ohm to attenuate?

 

[mtrycrafts]

But without the added resistor which I added to each of my front speaker I don’t have an equivalency of impedance between the speakers and the amp so does not it influence the sound?
My amp is intended for 6 ohm and my speakers are 4 ohm so I added 2 ohms to each speaker.
Also I am sorry but I didn’t understand the damping link that you gave me, can I reach you through an icq number or messenger, if so what is your number?

You can send an private message on this board? Low damping factor affects your speakers control. Adding that resistor will bring the damping factor below 10, like 2 in your case?

 

[MacManNM]

What about Bob?

It doesn't take a 3dB variation, does it? How does Carver demonstrate his amps with that output resistor of only 1 ohm to attenuate?

You have said again and again that any delta less than 3 db is not audible.

So, I guess we can all toss a resistor on our speakers and change the entire tonal quality of our systems?

Again, where is the scientific proof that a resistor on the output is going to change the FR? I'm sure you can find a paper on it somewhere.......can't you?

 

[MacManNM]

You can send an private message on this board? Low damping factor affects your speakers control. Adding that resistor will bring the damping factor below 10, like 2 in your case?

Again, how does putting a resistor in series change the damping factor of the amp?

 

[mtrycrafts]

Again, how does putting a resistor in series change the damping factor of the amp?

http://groups.google.com/group/rec.audio.tech/msg/ac12552519a4eb04?q=author:DPierce@world.std.com+back+emf&start=30&hl=en&lr=&ie=UTF-8&rnum=34

Interesting read. With his 4 ohm speaker, adding a 2 ohm resistor decreases damping to 2 or less, since the voice coil will be less than 4 ohms.

"Thus it becomes obvious that the electrical Q of the speaker or,
more generally, the electrical damping of the speaker, is NOT
dependent upon the source resistance Rs alone (as the proponents of
damping factor erroneously claim), but on the TOTAL series
resistance seen by the driver, including the DC resistance of the
voice coil, Re. This mistake, as commonly as it is made, the the
fatal flaw in the entire damping factor argument. "

The speaker see this added 2 ohn resistor.

 

[mtrycrafts]

You have said again and again that any delta less than 3 db is not audible.

So, I guess we can all toss a resistor on our speakers and change the entire tonal quality of our systems?

Again, where is the scientific proof that a resistor on the output is going to change the FR? I'm sure you can find a paper on it somewhere.......can't you?

That is at 16kHz and decreases to about .2dB at 4kHz.

 

[mtrycrafts]

I have a marantz 4500 receiver and the problem is it gets too hot because it is designed for 6 ohm speakers and my front speakers are 4 ohm so I added 2 ohm registers to each of the front speaker and it helped a little but now I am wondering if I can add 80 mm fan on top of the receiver.
Will the magnetic field of the receiver will effect the sound ?
Is it true that the more the receiver is hot it effects the sound clarity?

Maybe what I should have stated is that that 2 ohm speaker will rob your speaker of 1/3 of the amps power.

And, you are grossly affecting that speaker damping capability of the amp

 

[mtrycrafts]

Sound like a tube amp? What's a tube amp sound like?

Oh, it can sound euphonic, high end rolled off? Listen to a SET

 

[MacManNM]

http://groups.google.com/group/rec.audio.tech/msg/ac12552519a4eb04?q=author:DPierce@world.std.com+back+emf&start=30&hl=en&lr=&ie=UTF-8&rnum=34

Interesting read. With his 4 ohm speaker, adding a 2 ohm resistor decreases damping to 2 or less, since the voice coil will be less than 4 ohms.

"Thus it becomes obvious that the electrical Q of the speaker or,
more generally, the electrical damping of the speaker, is NOT
dependent upon the source resistance Rs alone (as the proponents of
damping factor erroneously claim), but on the TOTAL series
resistance seen by the driver, including the DC resistance of the
voice coil, Re. This mistake, as commonly as it is made, the the
fatal flaw in the entire damping factor argument. "

The speaker see this added 2 ohn resistor.

IMO Any audio amplifier with a dampning factor less than 10 should not even be considered for use in any audio system, other than a clock radio.

 

[Buckeyefan 1]

Oh, it can sound euphonic, high end rolled off? Listen to a SET

I have an old one. Great THD, and very warm.

 

[mtrycrafts]

I have an old one. Great THD, and very warm.

There you go

Just received this link from Wmax on amp affected by series resistance:

http://www.trueaudio.com/post_008.htm

 

[mtrycrafts]

IMO Any audio amplifier with a dampning factor less than 10 should not even be considered for use in any audio system, other than a clock radio.

Yes, exactely. But that is what he is turning his amp into, a 4 ohm speaker and a 2 ohm resistor

Just in case and for others to read:

http://www.trueaudio.com/post_008.htm

 

[mtrycrafts]

I have a marantz 4500 receiver and the problem is it gets too hot because it is designed for 6 ohm speakers and my front speakers are 4 ohm so I added 2 ohm registers to each of the front speaker and it helped a little but now I am wondering if I can add 80 mm fan on top of the receiver.
Will the magnetic field of the receiver will effect the sound ?
Is it true that the more the receiver is hot it effects the sound clarity?

I am sure I was correct now, thanks to Wmax:

http://www.trueaudio.com/post_008.htm

 

[MacManNM]

Yes, exactely. But that is what he is turning his amp into, a 4 ohm speaker and a 2 ohm resistor

Just in case and for others to read:

http://www.trueaudio.com/post_008.htm

Good post, however this does not take into account of the output impedance of the amplifier. With properly matched output impedance, this number becomes inaudible. At the same time, if it was properly matched in the first place, the resistor wouldn't have been installed. Bottom line, buy a better amp.

 

[WmAx]

I am sure I was correct now, thanks to Wmax:

http://www.trueaudio.com/post_008.htm

Yes, total series resistance of the circuit between the amp terminals and speaker has a direct effect on the damping factor of the amplifier. An amplifier with 0.1 ohms output impedance with a speaker cable[or resistor] offering a total of 2 ohms resistance in the circuit would have the same effect on frequency response of a speaker with a dynamic impedance as a 2.1 ohm output impedance amplifier would have. There is actually a good article on this site about amplifier damping factor:

http://www.audioholics.com/techtips/audioprinciples/amplifiers/dampingfactor.php

-Chris

 

[WmAx]

With properly matched output impedance, this number becomes inaudible. At the same time, if it was properly matched in the first place, the resistor wouldn't have been installed. Bottom line, buy a better amp.

I think the point may have been[I am not fully up to speed on this thread] that a resistor can allow a 'good' amp to sound like a 'poor' one[poor = very low damping factor].

-Chris

 

[mtrycrafts]

Yes, total series resistance of the circuit between the amp terminals and speaker has a direct effect on the damping factor of the amplifier. An amplifier with 0.1 ohms output impedance with a speaker cable[or resistor] offering a total of 2 ohms resistance in the circuit would have the same effect on frequency response of a speaker with a dynamic impedance as a 2.1 ohm output impedance amplifier would have. There is actually a good article on this site about amplifier damping factor:

http://www.audioholics.com/techtips/audioprinciples/amplifiers/dampingfactor.php

-Chris

That is the same as this by Richard Pierce from 1999.

http://groups.google.com/group/rec.audio.tech/msg/ac12552519a4eb04?q=author:DPierce@world.std.com+back+emf&start=30&hl=en&lr=&ie=UTF-8&rnum=34

Who is the original author? Is someone plagerizing?

the original poster placed a 2 ohm resistor in series with a 4 ohm speaker beacuse his amp is speced for 6 ohms

He is also robbed of 1/3 of his power