Receiver first or speakers?

[Sylar]

Am a newbie, and I have read a bit about receivers and set my eyes upon a few.
I have a more basic question. Should i choose my speakers first & then my receiver or, receiver first & then my speakers. If it does matter, how?

 

[TLS Guy]

Am a newbie, and I have read a bit about receivers and set my eyes upon a few.
I have a more basic question. Should i choose my speakers first & then my receiver or, receiver first & then my speakers. If it does matter, how?

Always speakers first. If you don't pick the speakers first you don't know how to power them..

 

[STRONGBADF1]

Am a newbie, and I have read a bit about receivers and set my eyes upon a few.
I have a more basic question. Should i choose my speakers first & then my receiver or, receiver first & then my speakers. If it does matter, how?

Welcome Sylar,

Pick the speakers you like first. That way you know what kind of load you need to drive.

 

[j_garcia]

Always speakers first. If you don't pick the speakers first you don't know how to power them..

Right there is your answer.

 

[Ares]

+4 on what has been said.

 

[Sylar]

Welcome Sylar,

Pick the speakers you like first. That way you know what kind of load you need to drive.

Thank you!

Always speakers first. If you don't pick the speakers first you don't know how to power them..

"what kind of load you need to drive"
"you don't know how to power them"

What exactly does, this mean? Impedance matching?
It would be great if one could share some links. I have some technical background, a bit rusty though.

 

[TLS Guy]

Thank you!



"what kind of load you need to drive"
"you don't know how to power them"

What exactly does, this mean? Impedance matching?
It would be great if one could share some links. I have some technical background, a bit rusty though.

I was afraid you might ask that.

Next time we will tell people to buy the receiver first.

The problem is difficult, because the vast majority of speaker manufactures publish meaningless and incomplete specifications.

The issue basically boils down to: -

Speaker sensitivity, for every 3 db decrease in spec. you need twice the amplifier power for the same spl.

Next is impedance. Here is the problem, because very, very few speakers have flat impedance curves. Only the Maggies come immediately to mind.

Speaker impedance is a curve and varies with frequency. So if possible you need to find a curve. As a rough rule of thumb rate the speaker at 10% above the minimum impedance, if the manufacturer specs it, or from an impedance graph of the speaker if you can find one from a third party review.

The next issue is phase angles.

Now an audio signal is not DC so there is an angle in phase between voltage and current.

Now when a speaker has phase angles in negative territory there is a gap between the apparent power the speaker requires and the true actual power consumed, which increase as the phase angle heads into negative territory. The hooker is that the current for the apparent power demands has to be provided by the amp. You get no hint of this from the impedance curve. So to make an informed choice you need both an impedance and a phase curve. The problem is you seldom have it.

This post I did last week shows that this excellent little sealed bookshelf speaker to be a difficult load and actually requiring robust amplification. You would not know that from the impedance curve alone.


So what to do.

If a speaker has two woofers or more, and if the above data is unobtainable, assume the speaker is 4 ohm, no matter what the manufacturer claims.

Look at the sensitivity spec.

Avoid entry level receivers, and make sure you buy one that is four ohm capable.

Always buy a receiver with pre outs, so you can add capable external amplification, if you end up on the rocks, after doing due diligence.

Post here on the speakers you intend to purchase. A lot of us here have some sense of what speakers are particularly difficult loads, after fielding others problem posts.

If a speaker is a difficult load it does not mean it is a bad speaker. Unfortunately for the budget conscious there is a trend towards, the better more exotic speakers being difficult loads.

 

[STRONGBADF1]

As TLSGuy said:

Post here on the speakers you intend to purchase. A lot of us here have some sense of what speakers are particularly difficult loads, after fielding others problem posts.

This is the easiest way to get it right. Let us know what speaker you want to buy and then we can recommended some receivers/ prepro & amp combo to consider.

 

[Sylar]

Speaker sensitivity, for every 3 db decrease in spec. you need twice the amplifier power for the same spl.

Next is impedance. Here is the problem, because very, very few speakers have flat impedance curves. Only the Maggies come immediately to mind.

Speaker impedance is a curve and varies with frequency.

I learnt a lot, from just less than half your post!
Did a lot of searching and a bit of reading. Here's a quick summary of what I came up with so far.

Speakers are highly inefficient (roughly 1% efficiency??) when it comes to converting electric energy into sound. To double the loudness or SPL (such that human ear can perceive this as double), one needs about 10 times as much power as before to achieve it. For a 3dB moderate increase in SPL, one requires to double the input power. Hence with higher requirements of SPL, power requirements can tend to drastically shoot up in certain scenarios (as high as 200W per channel). Supplying this high power is not a feasible for most of us. This is where speaker sensitivity kicks in. We can achieve the same 3dB increases using higher speaker sensitivity, 3dB higher sensitivity instead of doubling of power (Since power is a constraint for achieving high SPL).

Also music inherently has high power (higher than average) requirements for short periods, to reproduce certain tones. When power requirements shoot up as high as 200W per channel, if this power is not available at the amp, then the amp output is clamped, distortion can occur! Hence, the amp requires more power for these short bursts.
Also, as impedance varies with frequency, with low impedance again high power is again required.
Supplying high power can he achieved by using a hi quality PSU with high capacitances to store energy. Hence, matching of amp with the speaker becomes crucial and hence a high 'headroom' is desired.

Here are the links, in more detail.
Secrets of Amplifier and Speaker Power Requirements Revealed
The Nature of Power and Dynamic Headroom
The Interrelationship of Speakers and Amplifiers

A nice chart here to visualize better


I have a few questions here about a couple of things.

Max power transferable to speaker is at most half from amplifier. I presume this is why amps tend to heat up. Am I right? So do speakers also tend to heat up somewhere?

What happens when clamping occurs? How does this affect the speaker? I mean since power is clamped, what is the issue except for loss in reproduction of sound?

Also I read somewhere - don't remember where, 'Nowadays matching of impedance to load is not preferred much anymore. Higher efficiency is desired.'
What exactly does speaker efficiency mean?
I might be totally off here, kinda guessing by trying to add one and one.
Does efficiency mean the following..,
With matched impedances, as speakers are not very efficient when it comes to converting electric power into sound, we find a way to convert more of the 'lost power at the speaker' into sound (hence the term higher sensitivity). Achieving higher sensitivity, forces us to compromise on 'not matching impedances', resulting with more loss of power & more heat at the amp??

Feel free to hit me with a hammer if I am totally off


Consider a scenario with amplifiers which are not in the class of hi power amps. For instance I have a sony mini home theater system. It says PMPO 720W , guess it is about 20W per ch? Of course quality of reproduction of speakers is lower then the kind of models discussed here.
So does all amplifiers in the not so Hi Fi systems range, end up clipping & distorting?
The problem we faced in the high power scenario was in supplying that high power. What about for lower power systems, I presume the capacitance required to store energy is much lower & hence must be pretty cheap. So what is wrong in the ability of these systems to reproduce the sound? For the sake of this argument, am assuming that my lower end amp has multiple drivers in speakers to reproduce more accurately. I have read in many places that the sound cannot be reproduced with the same quality as with higher end systems do. What all am I missing here?

 

[JaBear]

You need to buy the speakers first, but don't blow all your money on them...I bought my speakers 5 months ago and still have yet to buy a AVR. I keep on getting upgraditis before I even buy anything... going from meh any 5.1 AVR will do to, I want the best AVR to why not get separates! It's never ending so set a budget for everything in advance.

 

[TLS Guy]

I learnt a lot, from just less than half your post!
Did a lot of searching and a bit of reading. Here's a quick summary of what I came up with so far.

Speakers are highly inefficient (roughly 1% efficiency??) when it comes to converting electric energy into sound. To double the loudness or SPL (such that human ear can perceive this as double), one needs about 10 times as much power as before to achieve it. For a 3dB moderate increase in SPL, one requires to double the input power. Hence with higher requirements of SPL, power requirements can tend to drastically shoot up in certain scenarios (as high as 200W per channel). Supplying this high power is not a feasible for most of us. This is where speaker sensitivity kicks in. We can achieve the same 3dB increases using higher speaker sensitivity, 3dB higher sensitivity instead of doubling of power (Since power is a constraint for achieving high SPL).

Also music inherently has high power (higher than average) requirements for short periods, to reproduce certain tones. When power requirements shoot up as high as 200W per channel, if this power is not available at the amp, then the amp output is clamped, distortion can occur! Hence, the amp requires more power for these short bursts.
Also, as impedance varies with frequency, with low impedance again high power is again required.
Supplying high power can he achieved by using a hi quality PSU with high capacitances to store energy. Hence, matching of amp with the speaker becomes crucial and hence a high 'headroom' is desired.

Here are the links, in more detail.
Secrets of Amplifier and Speaker Power Requirements Revealed
The Nature of Power and Dynamic Headroom
The Interrelationship of Speakers and Amplifiers

A nice chart here to visualize better


I have a few questions here about a couple of things.

Max power transferable to speaker is at most half from amplifier. I presume this is why amps tend to heat up. Am I right? So do speakers also tend to heat up somewhere?

What happens when clamping occurs? How does this affect the speaker? I mean since power is clamped, what is the issue except for loss in reproduction of sound?

Also I read somewhere - don't remember where, 'Nowadays matching of impedance to load is not preferred much anymore. Higher efficiency is desired.'
What exactly does speaker efficiency mean?
I might be totally off here, kinda guessing by trying to add one and one.
Does efficiency mean the following..,
With matched impedances, as speakers are not very efficient when it comes to converting electric power into sound, we find a way to convert more of the 'lost power at the speaker' into sound (hence the term higher sensitivity). Achieving higher sensitivity, forces us to compromise on 'not matching impedances', resulting with more loss of power & more heat at the amp??

Feel free to hit me with a hammer if I am totally off


Consider a scenario with amplifiers which are not in the class of hi power amps. For instance I have a sony mini home theater system. It says PMPO 720W , guess it is about 20W per ch? Of course quality of reproduction of speakers is lower then the kind of models discussed here.
So does all amplifiers in the not so Hi Fi systems range, end up clipping & distorting?
The problem we faced in the high power scenario was in supplying that high power. What about for lower power systems, I presume the capacitance required to store energy is much lower & hence must be pretty cheap. So what is wrong in the ability of these systems to reproduce the sound? For the sake of this argument, am assuming that my lower end amp has multiple drivers in speakers to reproduce more accurately. I have read in many places that the sound cannot be reproduced with the same quality as with higher end systems do. What all am I missing here?

First of all the specs of HTIBs are really optimistic and then some. It is the continuous power rating of an amp int a specified load that counts. For a good amp the power into a four ohm load should be about double the power into an eight ohm load.

The power an amp produces will be transferred to the speaker, but in most speakers the crossover eats half the power or better.

I don't think you mean clamping, but clipping.

Clipping occurs when the amp can not provide the power required into a given load and the sine wave has the tips flattened, hence the term clipping, and harmonics of the fundamental frequencies are generated. This sounds awful, especially if a lot of odd harmonics are present. These high frequency products can damage speakers, especially tweeters.

An amp driven often or severely into clipping will have a short life.

 

[AcuDefTechGuy]

I would do research first for about 6 months on Audioholics, learn about frequency response measurement graphs & all the specs, read The Audio Critic on line, save up some money, then when you have the full budget, buy both the speakers + AVR at the same time.

You may also do 2.0 first + the AVR, then save the money for the rest of the 5.1.

 

[Sylar]

I would do research first for about 6 months on Audioholics, learn about frequency response measurement graphs & all the specs, read The Audio Critic on line, save up some money, then when you have the full budget, buy both the speakers + AVR at the same time.

You may also do 2.0 first + the AVR, then save the money for the rest of the 5.1.

Yes, thot i'd read around a bit and then decide, ...but 6 months wud b too long a wait, lets see.
Buying a TV seemed much easier.

....save up some money, then when you have the full budget, buy both the speakers + AVR at the same time.

You may also do 2.0 first + the AVR, then save the money for the rest of the 5.1.

I have saved enough since have been working for a few yrs now.
My problem is in finding out what would be a 'sensible budget' or value for money system. Don't intent to upgrade now and then, like a PC.

My budget is around 1500$. Lesser - gr8, more - preferably not.

 

[AcuDefTechGuy]

Yes, thot i'd read around a bit and then decide, ...but 6 months wud b too long a wait, lets see.
Buying a TV seemed much easier.


I have saved enough since have been working for a few yrs now.
My problem is in finding out what would be a 'sensible budget' or value for money system. Don't intent to upgrade now and then, like a PC.

My budget is around 1500$. Lesser - gr8, more - preferably not.

Everyone is different.

My younger brother makes $140K/yr, yet he's not as much into this hobby as I am.

All he wants is a system that sounds clear (instead of muddy) with very good detail in the midrange and treble and "adequate" bass.

He listened to my Infinity P362 in my family room (powered by a cheap Denon 391), said loved the sound of it, and said he wanted to buy them.

I would do some search on the Infinity P362/363.

No speakers are perfect for everyone, but these are just one example.

 

[Sylar]

For a good amp the power into a four ohm load should be about double the power into an eight ohm load.

I have come across a couple of brands which specify only at 8Ω load.
Whats the logic behind ur reasoning? I can search if you could point me in the right direction.

I don't think you mean clamping, but clipping.

yup...I meant clipping

An amp driven often or severely into clipping will have a short life.

So when I add this with, 'more headrooom is better', isnt it a good idea to have a more powerful amp and reduce the gain? (Have read about gains, unsure how is this done, or if possible/advisable. Is this done by opening the box?)

Read somwhere earlier, when an amp comes to 0dB point - volume, the manufacturer advises it to be no longer safe to increase volume further. But doesn't it mean that there is already a significant amount of clipping at 0dB or just before, just not significant enough to cause damage?

 

[Sylar]

All he wants is a system that sounds clear (instead of muddy) with very good detail in the midrange and treble and "adequate" bass.

I didnt know how to put it in words, but I think this is what I am looking for. (Maybe if you give another description I wud say that too :-D)
Basically music & movies is what I will use my system for. Clear audible sound without much noise, should be clear even at low volumes. With my HTIB i have this tendency to increase volume to hear what is said, and it ends up being quite loud. There is also an 'acoustic problem' in that room. Maybe it is a combo of both.

I would do some search on the Infinity P362/363.
.

Where I live, my choices are pretty limited in available brands.
From little research I have done so far, available brands are JBL, Yamaha, Polk Audio, Paradigm, Tannoy, DLS, Energy, Jammo.

 

[Sylar]

...learn about frequency response measurement graphs & all the specs, read The Audio Critic on line

Oh Damn!
I had presumed that when specs mention range like '20Hz - 20kHz', that it would mean the response is mostly flat in this range. I was reading this link, Understanding Speaker Frequency Response ....oh boy, how stupid of me to assume.

Seriously, why would it be called an audio amplifier if it dosen't reproduce frequencies in the audio range. Why at all does one need this spec? Do we have audio amps that dont amplify the audio range.
So since the graf speaks more about how it actually amplifies, shouldn't they show that instead.


The Audio Critic...thx for the link.
One clarification...
So when you had mentioned to learn about the graphs, this is what you basically meant, watch out for non-flat responses.
...and by specs you basically meant specs of the device in question.

 

[AcuDefTechGuy]

Oh Damn!
I had presumed that when specs mention range like '20Hz - 20kHz', that it would mean the response is mostly flat in this range. I was reading this link, Understanding Speaker Frequency Response ....oh boy, how stupid of me to assume.

Seriously, why would it be called an audio amplifier if it dosen't reproduce frequencies in the audio range. Why at all does one need this spec? Do we have audio amps that dont amplify the audio range.
So since the graf speaks more about how it actually amplifies, shouldn't they show that instead.


The Audio Critic...thx for the link.
One clarification...
So when you had mentioned to learn about the graphs, this is what you basically meant, watch out for non-flat responses.
...and by specs you basically meant specs of the device in question.

And all speakers will behave and measure differently in every room.

Also keep in mind that what the manufacturer says is one thing, and how the speakers actually measure is another.

It's nice to have a 3rd party to "confirm" the measurements.

It's more believable when companies like Revel (Harman International) does the measurement because they have state-of-the-art anechoic chambers.

One take-home message is to look at both the on-axis frequency response and off-axis frequency response of the speakers.

For amps, read about it in The Audio Critic. You will see that as long as the power output is adequate, a $300 amp may sound like a $10,000 amp to many people. The Audio Critic's take home message is amps, pre-amps, CD players, DACs, wires, cables, and power cords sound the same most of the time to most people. Processors (DSPs & Room EQ like Audyssey, ARC, etc.) will sound differently. And Speakers are the most important element in the entire system.

Some people say they can tell the difference among amps and preamps and pre-pros and receivers even in Pure Direct mode and even when volume level-matched. I would like to give them the benefit of the doubt since I am a gentleman.

We don't have to agree on everything, which makes things more interesting anyway.