P

PENG

Audioholic Slumlord
That might have been the one I was thinking. It could be, if edited to include the considerations of:

- 8 ohm vs 4 ohm, and the associated dips

- a couple of simple numerical example, such as one to show a so called 4 ohm rated amp, could be less capable of driving 4 ohm speakers (such as a 120 W 8 ohm AVR, tested to be capable of 150 W 4 ohms for real world use, vs a 70 W 8 ohm or 4 ohm, but tested capable of doing 120 W 4 ohm for real world use. Case in point, may HTIAB speakers are 4 ohm rated.

Just to say get a power amp because you have 4 ohm nominal speakers is not necessarily helpful to someone on a tight budget but still want to enjoy music without worry about something that may nothe an issue. I know that may complicate things for people without much EE knowledge, that's why I think we need a very skillful writer to make the point that either you don't worry about the issue, or if you do, then don't go with internet hearsay, but try to understand the basic related EE/math based facts/calculations.

As it is now, those who read that article will still want his questions answered, based on the M&K speakers impedance, and for use the only safe answer without asking him a bunch questions back, is to recommend a 500 W 4 ohm rated amp, based on the specs:

Impedance4 ohm
Recommended Amplifier Power:25-500W
 
Last edited:
K

kalkent

Enthusiast
I don't know why it is so hard for people to understand any avrs can drive 4 ohm speakers given the right conditions, and most budget priced power amps such as this AMC thing, or even the better known Monolith, NAD, Anthem, cannot drive 4 ohm speakers under another sort of "right conditions".

@Steve81 : You are a superb technical writer and I think Audioholics might have an article, might have be by you, if not Gene, but would you consider writing another one that will answer the frequently ask "do I need an external amp, can my avr drive my 4 ohm speaker, or 8 ohm speaker that dips to 3.5 ohm, etc.etc.etc,, and make the article easy to find, and/or link by us regular members so we don't have to keep repeating the same thing every other week? Once and for all, please...

Note that I know it may be just my wishful thinking, but it is tiring to see the same kind of questions asked so many times, and since we like to help, we have to repeat ourselves so many times. So I hope Steve, or Gene can come up with something..

Back to the point I want to make again, I think we can agree that almost every long time members, at least on Audiohlics, ASR, AVS etc., seems to know, or claim to know, even quoted Ohms law and the power formula:

V=IR,
P=I*I*R=V*V/R=V*I

combined with important known facts:

1) speaker sensitivity is often expressed as X dB/2.83V/meter, or X dB/W/meter (less common, not preferred form)
2) each time you double the distance, say from 1 meter to 2 meter, you lose 6 dB of SPL (sound pressure level)
3) while 2) above shows distance is a huge factor, most room will have a room gain of about 3 dB in the mid bass to deep bass range so all that 6 dB is not loss, especially when subwoofers are used.
4) THX standard that many movie cinema follow, is to aim for SPL of 85 dB (sort of average, "reference level"), 105 dB peak
5) most home theater users will likely feel reference level is too loud and most will likely be happy enough with 75 dB average, 95 dB peak, many just don't know, don't care what spl they are listening to, but 75 dB/95 dB, imo is a good bet. For me, it is more like 70/90, occasionally 75/95 just for the extra thrill.
6) To gain 3 dB SPL, power has to increase by 2 times, and to gain 10 dB, power must increase by 10 times, conversely, if you are happy with 10 dB lower SPL, your power requirement will drop by 10 times too.
7) Even very low impedance dips may not be an issue for even an AVR because it depends on the bandwidth of the dip, and the duration of the dip, so it depends a lot of the media contents

It is so evident from the above commonly known and understood simple electrical formula that any AVRs can drive 4 ohm speakers, one cannot generalize and has to gather up the surrounding facts. If one simply grabs one of those so called 4 ohm capable power amp such as the entry level Emotiva Bas X A series, they may or may not do justice to their speakers, and/or could have just use their AVR and would have been fine.

Here is a numercal example, using the OP's M&K S150:

sensitivity: 92 dB/2.84V/m
impedance: 4 ohm
Thanks to @ErinH , (I hope this is the same Erin of Erin's audio corner and if not, someone will correct me) we have the needed info, instead of the silly single number, to work with:

Again, don't blindly base your decision on the single value, look at the graphs!
From this graph, you can see that phase angle is not an issue, but the dip below 5 ohms spans the range between about 120 Hz and 800 Hz could be.

Still, if the OP sits within 10 ft, and listen to no louder than 10 dB below reference, most a lot of people do, the RZ50 will do fine. It is obviously better to use a 3 channel external amp, but I am not sure about this AMC amp, their website does not provide much information, and the emphasis on "True RMS power" sounds an alarm to me, there is no such thing as RMS power, though it is widely used, so I am only alarmed by the facts that they says:

Such wording just don't inspire confidence, and if you look into the instruction manual, there is no 4 ohm power output rating, it just says 150 W (IMF) 8 ohm, clipping power 160 W 8 ohm

Why reference "IMF", that seems like a term/standard, rarely used in specifying power amp outputs these days?
They also claim "oversized" transformer, but there is no evidence of that if you look at the size of it in the picture.

Miller & Kreisel S150 Speaker Review (erinsaudiocorner.com)

View attachment 62925

The amp is still going to help for sure, but I would highly recommend the OP go with a more mainstay 3 channel, 200 W 8 ohms, 300 W 4 ohms rated power amp such as those offered by Monolith, that may not be available in Australia. There is also the Hypex class D amp options, such as March Audio's:

Amplifiers - March Audio

My suggestion is, try the Onkyo RZ50 AVR first, you may be surprised, that it can do the job nicely, if not then go to plan B.
I think its hard because we're not confident in what we know.

We come to places like this, audiosciencereview, YouTube and try to find the people that put out good information and even then it can be conflicting.

Your first paragraph for instance, and this isn't a shot at you but I don't understand what it means.

When you say

"I don't know why it is so hard for people to understand any avrs can drive 4 ohm speakers given the right conditions, and most budget priced power amps such as this AMC thing, or even the better known Monolith, NAD, Anthem, cannot drive 4 ohm speakers under another sort of "right conditions""

To me it seems like you're saying, people seem to think an avr can't drive 4ohm speakers, when it actually can, but they think a power amp can drive those 4ohm speakers better, when it probably can't do a better job than the avr.

Thank you for listing it all out, it makes sense to me that way and its definitely helpful.

I have a question regarding the THX certification. Does that mean it's not a useless certification and any avr with the THX certification should be able to play at 85db in the specified room size?

In regards to the m&k speakers it's very common to hear people say "they love power, feed them enough power and the speakers will shine".

That is where I get confused about power amps. The equation says I shouldn't have any issues but why is it such a common held belief the speakers do so much better with a good power amp.

I think you may be right about the power amp. I may have shot myself in the foot there and not made a smart purchase.
 
Steve81

Steve81

Audioholics Five-0
That might have been the one I was thinking.
I'm not a writer for AH these days, just FYI. I just hang out on the boards and moderate :D
I'll ping @gene so he can consider your kind suggestions.

Perhaps a dedicated section for "primer" articles would be advisable for neophytes coming to AH for advice?
 
P

PENG

Audioholic Slumlord
I'm not a writer for AH these days, just FYI. I just hang out on the boards and moderate :D
I'll ping @gene so he can consider your kind suggestions.

Perhaps a dedicated section for "primer" articles would be advisable for neophytes coming to AH for advice?
"primer" articles sound like the ticket, nothing is 100%, but I think it will help a lot, as AH has so many articles.
 
Steve81

Steve81

Audioholics Five-0
"primer" articles sound like the ticket, nothing is 100%, but I think it will help a lot, as AH has so many articles.
If nothing else, it will give you an easy reference to point to without having to sift through articles:p
 
P

PENG

Audioholic Slumlord
I think its hard because we're not confident in what we know.

We come to places like this, audiosciencereview, YouTube and try to find the people that put out good information and even then it can be conflicting.
I know, that's why I tried to get Steve81 to write something.

Your first paragraph for instance, and this isn't a shot at you but I don't understand what it means.

To me it seems like you're saying, people seem to think an avr can't drive 4ohm speakers, when it actually can, but they think a power amp can drive those 4ohm speakers better, when it probably can't do a better job than the avr.
You understood right. The fact is, it depends. Say, your actual power need based on your listening habit and speakers is 0.2 W average (such as it is for me) 20 W peak, then it is very likely that an AVR rated 125 W 8 ohms such as the AVR-X4800H can do as good a job as a 200 W 8 ohm 300 W 4 ohm power amp, let alone those so called entry level Emotiva or even Outlaw power amps. That's because power not used will not make a difference, all else being equal. Since all else are not always equal, that adds to more confusion, such as when you read often about how someone added a power amp to help an AVR, the sound quality sounds night and day difference, that typically means either its all in the person's head, or the person was not doing an apples to apples comparison, such as not level matching, comparing the units in different rooms, with different speakers, source contents etc.

Want more confusion? Most of use might have read posts that claim:
- You can't have too much power.
- People don't realize how little they actually used, such as no more than a few watts..
- People's amps clip more often than they realize.

All of such claims can be true, it sounds confusing, because posters don't usually clearly state all the other factors, circumstantial conditions, or caveats!

I have a question regarding the THX certification. Does that mean it's not a useless certification and any avr with the THX certification should be able to play at 85db in the specified room size?
It is not useless, but the readers have to try and understand more about it, at least pay a visit to the THX website. There are also different levels of certification.

THX Certified Audio - Hear the difference THX can make

In regards to the m&k speakers it's very common to hear people say "they love power, feed them enough power and the speakers will shine".
I know.., but it's a relative thing, so again, in some cases, they are fine without a ton of power, while in other cases, they would suck the amp dry.

That is where I get confused about power amps. The equation says I shouldn't have any issues but why is it such a common held belief the speakers do so much better with a good power amp.
Again, that's one reason why I try to convince Steve81 to write something about it. He doesn't do that anymore but hopeful he can convince Gene. If @gene does it, trust it will be done right. I could do something too, but I really don't like technical writing that much and Gene knows much more about audios.

Edit: I forgot to mention that since AVRs typically don't use power supplies as robust as real separate power amps that have similar power output ratings, so in margin case, even if the calculated requirements seem adequate, in real world applications, it may not stay clear of their clipping points. Properly sized power amps may therefore make a difference in such cases.

For example:
Scenario A: Let's say you use an online calculator to estimate your power need, and it shows 2 W average, 200 watt 8 ohms for peaks, a power amp rated 200 W 8 ohm will most likely do great, without clipping whereas a 125 W AVR such as the AVR-X4800H would be clipping, when pushed to your target spl limit.

Scenario B: Same assumptions as in A), except the calculated requirement is 0.5 W average, 50 W peak 8 ohms, in this case the 125 W 8 ohm rated Denon will not likely clip, and therefore in this scenario, adding the same power amp will not make an audible difference, all else being equal. Though we know in practice, many people will hear a difference while many will not. Those who heard the difference, if the comparison is done properly, will only hear it in sighted comparison listening.

So yes, while the formula works, it is a matter of margin. In my opinion, if the calculator tells you your requirement is 0.5W average, 50 W peak, you don't need an external power amp to help the AVR-X4800H, but it the requirement is 1 W average, 100 W peak, then you do need an external amp, but get one that is rated 200 W 8 ohms.

This has little to do with headroom, and amplifier headroom is another spec that is prone to misconception, and confusion. Many amp designers, manufacturers will tell you more headroom is good while just as many may tell you less is good.

For example, Anthem's FAQ:
Frequently Asked Questions | Anthem® (anthemav.com)
How much headroom do your amps have?
Careful - headroom numbers are usually misleading. A smaller figure is better here because headroom should really be called "how much does the power supply sag while stressed for more than a fraction of a second".
Regardless, if you think you need 0.5 W average, 50 W peak, get an amp that is rated at least 100 W average (therefore 200 W peak), better still, 200 W average. Don't count on an amp that is 100 W average but claim it has 3 dB headroom, therefore can actually push 200 W short term.. I would take the one that is rated 150 W average, and only 1.2 dB headroom, per Anthem's rationale.

I think you may be right about the power amp. I may have shot myself in the foot there and not made a smart purchase.
I am not sure, you mean you bought that AMC amp? For the price, it can be a good one too, something similar to Emotiva's (in the US) I would guess. I just don't think it will bring anything (depending on your actual power need) to the table, other than taking load off the AVR.
 
Last edited:
panteragstk

panteragstk

Audioholic Warlord
the 4 ohm spec is nominal - any speaker with "nominal" 4 ohm will have dips that go well below that!

Reviews of AVR's from Onkyo, Denon, Yamaha, have all shown issues with handling of 4ohm nominal speakers... basically the mass market AVR's don't have a sufficiently robust power supply to provide the amps needed for low impedance speakers.
That's exactly my thinking.
 
panteragstk

panteragstk

Audioholic Warlord
I don't know why it is so hard for people to understand any avrs can drive 4 ohm speakers given the right conditions, and most budget priced power amps such as this AMC thing, or even the better known Monolith, NAD, Anthem, cannot drive 4 ohm speakers under another sort of "right conditions".

@Steve81 : You are a superb technical writer and I think Audioholics might have an article, might have be by you, if not Gene, but would you consider writing another one that will answer the frequently ask "do I need an external amp, can my avr drive my 4 ohm speaker, or 8 ohm speaker that dips to 3.5 ohm, etc.etc.etc,, and make the article easy to find, and/or link by us regular members so we don't have to keep repeating the same thing every other week? Once and for all, please...

Note that I know it may be just my wishful thinking, but it is tiring to see the same kind of questions asked so many times, and since we like to help, we have to repeat ourselves so many times. So I hope Steve, or Gene can come up with something..

Back to the point I want to make again, I think we can agree that almost every long time members, at least on Audiohlics, ASR, AVS etc., seems to know, or claim to know, even quoted Ohms law and the power formula:

V=IR,
P=I*I*R=V*V/R=V*I

combined with important known facts:

1) speaker sensitivity is often expressed as X dB/2.83V/meter, or X dB/W/meter (less common, not preferred form)
2) each time you double the distance, say from 1 meter to 2 meter, you lose 6 dB of SPL (sound pressure level)
3) while 2) above shows distance is a huge factor, most room will have a room gain of about 3 dB in the mid bass to deep bass range so all that 6 dB is not loss, especially when subwoofers are used.
4) THX standard that many movie cinema follow, is to aim for SPL of 85 dB (sort of average, "reference level"), 105 dB peak
5) most home theater users will likely feel reference level is too loud and most will likely be happy enough with 75 dB average, 95 dB peak, many just don't know, don't care what spl they are listening to, but 75 dB/95 dB, imo is a good bet. For me, it is more like 70/90, occasionally 75/95 just for the extra thrill.
6) To gain 3 dB SPL, power has to increase by 2 times, and to gain 10 dB, power must increase by 10 times, conversely, if you are happy with 10 dB lower SPL, your power requirement will drop by 10 times too.
7) Even very low impedance dips may not be an issue for even an AVR because it depends on the bandwidth of the dip, and the duration of the dip, so it depends a lot of the media contents

It is so evident from the above commonly known and understood simple electrical formula that any AVRs can drive 4 ohm speakers, one cannot generalize and has to gather up the surrounding facts. If one simply grabs one of those so called 4 ohm capable power amp such as the entry level Emotiva Bas X A series, they may or may not do justice to their speakers, and/or could have just use their AVR and would have been fine.

Here is a numercal example, using the OP's M&K S150:

sensitivity: 92 dB/2.84V/m
impedance: 4 ohm
Thanks to @ErinH , (I hope this is the same Erin of Erin's audio corner and if not, someone will correct me) we have the needed info, instead of the silly single number, to work with:

Again, don't blindly base your decision on the single value, look at the graphs!
From this graph, you can see that phase angle is not an issue, but the dip below 5 ohms spans the range between about 120 Hz and 800 Hz could be.

Still, if the OP sits within 10 ft, and listen to no louder than 10 dB below reference, most a lot of people do, the RZ50 will do fine. It is obviously better to use a 3 channel external amp, but I am not sure about this AMC amp, their website does not provide much information, and the emphasis on "True RMS power" sounds an alarm to me, there is no such thing as RMS power, though it is widely used, so I am only alarmed by the facts that they says:

Such wording just don't inspire confidence, and if you look into the instruction manual, there is no 4 ohm power output rating, it just says 150 W (IMF) 8 ohm, clipping power 160 W 8 ohm

Why reference "IMF", that seems like a term/standard, rarely used in specifying power amp outputs these days?
They also claim "oversized" transformer, but there is no evidence of that if you look at the size of it in the picture.

Miller & Kreisel S150 Speaker Review (erinsaudiocorner.com)

View attachment 62925

The amp is still going to help for sure, but I would highly recommend the OP go with a more mainstay 3 channel, 200 W 8 ohms, 300 W 4 ohms rated power amp such as those offered by Monolith, that may not be available in Australia. There is also the Hypex class D amp options, such as March Audio's:

Amplifiers - March Audio

My suggestion is, try the Onkyo RZ50 AVR first, you may be surprised, that it can do the job nicely, if not then go to plan B.
Thanks for putting that together!
 
K

kalkent

Enthusiast
I know, that's why I tried to get Steve81 to write something.

Your first paragraph for instance, and this isn't a shot at you but I don't understand what it means.



You understood right. The fact is, it depends. Say, your actual power need based on your listening habit and speakers is 0.2 W average (such as it is for me) 20 W peak, then it is very likely that an AVR rated 125 W 8 ohms such as the AVR-X4800H can do as good a job as a 200 W 8 ohm 300 W 4 ohm power amp, let alone those so called entry level Emotiva or even Outlaw power amps. That's because power not used will not make a difference, all else being equal. Since all else are not always equal, that adds to more confusion, such as when you read often about how someone added a power amp to help an AVR, the sound quality sounds night and day difference, that typically means either its all in the person's head, or the person was not doing an apples to apples comparison, such as not level matching, comparing the units in different rooms, with different speakers, source contents etc.

Want more confusion? Most of use might have read posts that claim:
- You can't have too much power.
- People don't realize how little they actually used, such as no more than a few watts..
- People's amps clip more often than they realize.

All of such claims can be true, it sounds confusing, because posters don't usually clearly state all the other factors, circumstantial conditions, or caveats!



It is not useless, but the readers have to try and understand more about it, at least pay a visit to the THX website. There are also different levels of certification.

THX Certified Audio - Hear the difference THX can make



I know.., but it's a relative thing, so again, in some cases, they are fine without a ton of power, while in other cases, they would suck the amp dry.



Again, that's one reason why I try to convince Steve81 to write something about it. He doesn't do that anymore but hopeful he can convince Gene. If @gene does it, trust it will be done right. I could do something too, but I really don't like technical writing that much and Gene knows much more about audios.

Edit: I forgot to mention that since AVRs typically don't use power supplies as robust as real separate power amps that have similar power output ratings, so in margin case, even if the calculated requirements seem adequate, in real world applications, it may not stay clear of their clipping points. Properly sized power amps may therefore make a difference in such cases.

For example:
Scenario A: Let's say you use an online calculator to estimate your power need, and it shows 2 W average, 200 watt 8 ohms for peaks, a power amp rated 200 W 8 ohm will most likely do great, without clipping whereas a 125 W AVR such as the AVR-X4800H would be clipping, when pushed to your target spl limit.

Scenario B: Same assumptions as in A), except the calculated requirement is 0.5 W average, 50 W peak 8 ohms, in this case the 125 W 8 ohm rated Denon will not likely clip, and therefore in this scenario, adding the same power amp will not make an audible difference, all else being equal. Though we know in practice, many people will hear a difference while many will not. Those who heard the difference, if the comparison is done properly, will only hear it in sighted comparison listening.

So yes, while the formula works, it is a matter of margin. In my opinion, if the calculator tells you your requirement is 0.5W average, 50 W peak, you don't need an external power amp to help the AVR-X4800H, but it the requirement is 1 W average, 100 W peak, then you do need an external amp, but get one that is rated 200 W 8 ohms.

This has little to do with headroom, and amplifier headroom is another spec that is prone to misconception, and confusion. Many amp designers, manufacturers will tell you more headroom is good while just as many may tell you less is good.

For example, Anthem's FAQ:
Frequently Asked Questions | Anthem® (anthemav.com)


Regardless, if you think you need 0.5 W average, 50 W peak, get an amp that is rated at least 100 W average (therefore 200 W peak), better still, 200 W average. Don't count on an amp that is 100 W average but claim it has 3 dB headroom, therefore can actually push 200 W short term.. I would take the one that is rated 150 W average, and only 1.2 dB headroom, per Anthem's rationale.



I am not sure, you mean you bought that AMC amp? For the price, it can be a good one too, something similar to Emotiva's (in the US) I would guess. I just don't think it will bring anything (depending on your actual power need) to the table, other than taking load off the AVR.
Thanks for taking the time to write all that down. I have read it a few times and can guarantee I'll read it a few more.

I went and watched a YouTube video on calculating required power and I came out with needing 32w for peaks at 95db.

I was making the assumption based on the level I listen at usually -15.

I could be completely wrong though.

When I added the power amp, I didn't notice a night and day difference but I noticed what I thought was a cleaner sound, sound effects sounded more precise.

Regarding the thx certification. I imagine the rz50 being thx select certified then that means its been independently tested to play at reference levels in a 3000²ft room without significant distortion.

If thats the case, that's a pretty decent indicator it can get the job done.

I have a slightly off topic question but you seem to have a fair bit of knowledge so I thought I would throw it out there.

I've been trying to find a difference between the rz50 and the integra drx5.4.

A lot of people say the integra has better internal components but they can't specify what components are of higher spec.

Are you aware of what the actual differences are?

There are quite a number of reports on the onkyo being unreliable, it makes me hesitant to go down that path again.

Thanks again for your time.
 
Theetjuh

Theetjuh

Enthusiast
From what I know the internal components aren't any different between the Pioneer, Onkyo or Integra.

What is different is the software options that are available, @dlaloum showed a few times that one of the main differences is the preset listening mode based on incoming audio stream.
So setting the listening mode to DTS Neural:X when DTS audio is played and Dolby Surround when DD audio is played.

This isn't possible on the Pioneer and Onkyo models.
 
P

PENG

Audioholic Slumlord
Thanks for taking the time to write all that down. I have read it a few times and can guarantee I'll read it a few more.

I went and watched a YouTube video on calculating required power and I came out with needing 32w for peaks at 95db.

I was making the assumption based on the level I listen at usually -15.

I could be completely wrong though.
Two things to keep in mind:

1) volume -15 means very little, without knowing the input level, so you estimated 32 W peaks for 95 dB spl could be completely wrong, sorry..

2) You can however, estimate how many watts you required to produce 95 dB spl assuming the 95 dB peak is from playing a movie recorded/mastered to THX standard.

On 2), I did a quick estimate and came with roughly 5 to 7 W, one channel, based on 4 ohms.

For your estimation, you are better off using the following calculators and ignore those YT video, unless you know for sure the presenter has the relevant knowledge.

Peak SPL Calculator (hometheaterengineering.com)

This calculator, in fact most of the online one, are based on 8 ohms, so for your M&K S150, don't enter 92 dB sensitivity, but derate to 89 dB, in order to get more accurate results. For number of speakers, if you want to follow THX, enter one, no matter how many you will actually use.

When I added the power amp, I didn't notice a night and day difference but I noticed what I thought was a cleaner sound, sound effects sounded more precise.
That's normal, for sighted comparison, if level matched and have someone else switch for you, such perceive differences will very likely disappear, or there is a subtle difference that allows you to score a little better than 50% of the time.

Regarding the thx certification. I imagine the rz50 being thx select certified then that means its been independently tested to play at reference levels in a 3000²ft room without significant distortion.

If thats the case, that's a pretty decent indicator it can get the job done.
That sounds fair.

I have a slightly off topic question but you seem to have a fair bit of knowledge so I thought I would throw it out there.
I usually don't comment unless I have the relevant facts, such as from reading owner's manuals, service manuals, bench test results. I don't usually comment based on subjective reviews, I may quote some of those to make my points, but would never take such reviews seriously, for obvious reasons.

I've been trying to find a difference between the rz50 and the integra drx5.4.

A lot of people say the integra has better internal components but they can't specify what components are of higher spec.

Are you aware of what the actual differences are?
Without seeing their service manuals, it is not possible to know whether they use different internal components/parts. Also, manufacturers don't always publish accurate information on their website. For example, we know for fact that many of them had replaced the AKM DAC IC shortly after the AKM factory fire, yet for a long time they were still listing the AK4458 on their website, I am not sure if that's consider false advertisement, but many for sure would have bought the products based on some false information they had seen on manufacturer websites. As a matter of fact, at least one Integra website, still say the DAC IC is the AK4458 when it is almost certain that it isn't, but you can't prove it unless you someone take one apart.

Whoever claim Integra uses better parts in the DRX5.4 vs the RZ50 should not be taken as facts, unless they can show the evidence.

There are quite a number of reports on the onkyo being unreliable, it makes me hesitant to go down that path again.
That is also hard to say, without seeing some apples to apples statistics, who knows? If you buy from an authorized dealer that offers a long return windows, and use the unit every day when it is within the exchange window, then if it fails you can return if without having to take a loss (may have to pay for shipping if bought online). If it works great for even 30 days, chances are you will be fine for a number of years.
 
K

kalkent

Enthusiast
Two things to keep in mind:

1) volume -15 means very little, without knowing the input level, so you estimated 32 W peaks for 95 dB spl could be completely wrong, sorry..

2) You can however, estimate how many watts you required to produce 95 dB spl assuming the 95 dB peak is from playing a movie recorded/mastered to THX standard.

On 2), I did a quick estimate and came with roughly 5 to 7 W, one channel, based on 4 ohms.

For your estimation, you are better off using the following calculators and ignore those YT video, unless you know for sure the presenter has the relevant knowledge.

Peak SPL Calculator (hometheaterengineering.com)

This calculator, in fact most of the online one, are based on 8 ohms, so for your M&K S150, don't enter 92 dB sensitivity, but derate to 89 dB, in order to get more accurate results. For number of speakers, if you want to follow THX, enter one, no matter how many you will actually use.



That's normal, for sighted comparison, if level matched and have someone else switch for you, such perceive differences will very likely disappear, or there is a subtle difference that allows you to score a little better than 50% of the time.



That sounds fair.



I usually don't comment unless I have the relevant facts, such as from reading owner's manuals, service manuals, bench test results. I don't usually comment based on subjective reviews, I may quote some of those to make my points, but would never take such reviews seriously, for obvious reasons.



Without seeing their service manuals, it is not possible to know whether they use different internal components/parts. Also, manufacturers don't always publish accurate information on their website. For example, we know for fact that many of them had replaced the AKM DAC IC shortly after the AKM factory fire, yet for a long time they were still listing the AK4458 on their website, I am not sure if that's consider false advertisement, but many for sure would have bought the products based on some false information they had seen on manufacturer websites. As a matter of fact, at least one Integra website, still say the DAC IC is the AK4458 when it is almost certain that it isn't, but you can't prove it unless you someone take one apart.

Whoever claim Integra uses better parts in the DRX5.4 vs the RZ50 should not be taken as facts, unless they can show the evidence.



That is also hard to say, without seeing some apples to apples statistics, who knows? If you buy from an authorized dealer that offers a long return windows, and use the unit every day when it is within the exchange window, then if it fails you can return if without having to take a loss (may have to pay for shipping if bought online). If it works great for even 30 days, chances are you will be fine for a number of years.
The YouTube channel was home theatre guys, I didn't mention their name as I wasn't sure if we were allowed to mention others here. I assumed he knew what he was talking about with the calculations, his videos seem to be in-depth but..

I only used-15 as a reference, as in his video he said once everything was calibrated properly the avr sees 0 as reference level. So -15 would essentially be 15db below reference level.

Unfortunately in Australia we have very good warranty periods but we don't really have the same system as what it seems like guys in the US have. Where they can buy something try it for 30 days and if they don't like it or it doesn't perform to how they expect they can return it.

If we're not happy with a product and it still works, it's essentially tough luck. Unless it doesnt do something significant we were lead to believe it was capable of doing.

I had an epson projector that was clearly faulty out of the box, and they wouldn't take it back. I had to send it to a repair technician to attempt a repair and the repair failed and it was still a fight to get my money back.
 
lovinthehd

lovinthehd

Audioholic Jedi
The YouTube channel was home theatre guys, I didn't mention their name as I wasn't sure if we were allowed to mention others here. I assumed he knew what he was talking about with the calculations, his videos seem to be in-depth but..

I only used-15 as a reference, as in his video he said once everything was calibrated properly the avr sees 0 as reference level. So -15 would essentially be 15db below reference level.

Unfortunately in Australia we have very good warranty periods but we don't really have the same system as what it seems like guys in the US have. Where they can buy something try it for 30 days and if they don't like it or it doesn't perform to how they expect they can return it.

If we're not happy with a product and it still works, it's essentially tough luck. Unless it doesnt do something significant we were lead to believe it was capable of doing.

I had an epson projector that was clearly faulty out of the box, and they wouldn't take it back. I had to send it to a repair technician to attempt a repair and the repair failed and it was still a fight to get my money back.
Got a link to that video? There's only a few on youtube I'd bother with and not familiar with home theater guys....

Yeah we're spoiled here in the US as consumers, particularly for audio compared to down under it seems by many reports....
 
K

kalkent

Enthusiast
Got a link to that video? There's only a few on youtube I'd bother with and not familiar with home theater guys....

Yeah we're spoiled here in the US as consumers, particularly for audio compared to down under it seems by many reports....
That was meant to say gurus not guys, my phone auto corrected.

I honestly thought we had it good here, but after seeing how good some of you guys get over there with electronics. I'm definitely jealous.

Being able to return something if it doesn't fit your expectations is awesome.

Here's the link

 
lovinthehd

lovinthehd

Audioholic Jedi
That was meant to say gurus not guys, my phone auto corrected.

I honestly thought we had it good here, but after seeing how good some of you guys get over there with electronics. I'm definitely jealous.

Being able to return something if it doesn't fit your expectations is awesome.

Here's the link

Thanks. I've heard generally good things about their videos, but I could only get to about 6 minutes (I just prefer to read stuff like this generally)....how did you do the calculation particularly? Or is there a point in the video where they are more concise?

I generally don't need to return anything myself, but is nice to know its an option if something isn't up to snuff.....but I tend to do my homework and don't have odd expectations (which there are a lot of in audio based on some really bad/goofy info out there).
 
P

PENG

Audioholic Slumlord
That was meant to say gurus not guys, my phone auto corrected.

I honestly thought we had it good here, but after seeing how good some of you guys get over there with electronics. I'm definitely jealous.

Being able to return something if it doesn't fit your expectations is awesome.

Here's the link

Thanks, when I get home I will watch it.
Your assumption that after calibration, 0 could be at about ref level but as I mentioned before, that's the case if the source content is recorded/mastered to THX standard for movies, and the level trims are at 0. Even if I used your method to estimate, I got a lot less than your 33 W, again, more like 5 to 8 watts, per channel, at volume -15, based on THX movie content during peaks.

Have you tried the calculator I linked, that will give you a good ball park estimate.

I could be wrong too, as I only did a quick check of your number, though I think it would be in the ball park.
 
K

kalkent

Enthusiast
Thanks. I've heard generally good things about their videos, but I could only get to about 6 minutes (I just prefer to read stuff like this generally)....how did you do the calculation particularly? Or is there a point in the video where they are more concise?

I generally don't need to return anything myself, but is nice to know its an option if something isn't up to snuff.....but I tend to do my homework and don't have odd expectations (which there are a lot of in audio based on some really bad/goofy info out there).
His stuff on atmos layouts and that seem to be pretty good. I guess they all have small differences in their recommendations but the fundamentals seem consistent.

I tend to over think this stuff, as you can probably tell from all my questions. Mostly because there is such conflicting information, trusting sales people is not really easy, and I've had issues with reliability and the hassle of repairs/replacements ubder warranty..

I'm sure the decision really isn't as hard as it feels for me.
 
K

kalkent

Enthusiast
Thanks, when I get home I will watch it.
Your assumption that after calibration, 0 could be at about ref level but as I mentioned before, that's the case if the source content is recorded/mastered to THX standard for movies, and the level trims are at 0. Even if I used your method to estimate, I got a lot less than your 33 W, again, more like 5 to 8 watts, per channel, at volume -15, based on THX movie content during peaks.

Have you tried the calculator I linked, that will give you a good ball park estimate.

I could be wrong too, as I only did a quick check of your number, though I think it would be in the ball park.
Yep, I tried that calculator and it came out to 5w.

I believe the way they worked it out on the video was

Choose the level you want at you mlp, then I think they added 10db above that for peaks. Mine came out to 95db.

My speakers are 92db, and my mlp is 3m away. So that comes down to (they took away 3db for each additional m) mine came down to 86db at mlp.

To get that up to 95db for the peaks you go up in 3db and double the power. They said with 4ohm speakers start at 2w.

So 2w, doubling that, 4w takes me up to 89db, doubke again is 8w that's 93db. Double again is 16w and 96db. They then said you want a small amount of headroom, so double once more is 32w to get 99db peaks at my mlp

I'm pretty sure that's how they worked it out.
 
lovinthehd

lovinthehd

Audioholic Jedi
His stuff on atmos layouts and that seem to be pretty good. I guess they all have small differences in their recommendations but the fundamentals seem consistent.

I tend to over think this stuff, as you can probably tell from all my questions. Mostly because there is such conflicting information, trusting sales people is not really easy, and I've had issues with reliability and the hassle of repairs/replacements ubder warranty..

I'm sure the decision really isn't as hard as it feels for me.
I think its a good thing you're looking into it and asking questions. Trusting sales people is something I just don't do with audio (and few other things). This is a good site for good information and reviews, audiosciencereview.com another (and for speakers I like Erin's Audio Corner too), maybe some stuff at avsforum.com. Many others, including some famous magazines and blogs are worthless for the most part, IMO.

Sorry to hear you have both retailer and warranty support issues (do you deal directly with the factory on warranty? Or is it thru the retailer?....think in the UK its common the retailer provides a warranty).
 
P

PENG

Audioholic Slumlord
Yep, I tried that calculator and it came out to 5w.

I believe the way they worked it out on the video was

Choose the level you want at you mlp, then I think they added 10db above that for peaks. Mine came out to 95db.

My speakers are 92db, and my mlp is 3m away. So that comes down to (they took away 3db for each additional m) mine came down to 86db at mlp.

To get that up to 95db for the peaks you go up in 3db and double the power. They said with 4ohm speakers start at 2w.

So 2w, doubling that, 4w takes me up to 89db, doubke again is 8w that's 93db. Double again is 16w and 96db. They then said you want a small amount of headroom, so double once more is 32w to get 99db peaks at my mlp

I'm pretty sure that's how they worked it out.
That sounds about right, but that is not based on volume -15 you based on earlier. In that scenario, my comments still stand. That is it would be a lot less, say 5-8 w, or less than 10 w for sure.

Your best bet is to ignore such videos but use the calculator that has been linked on this forum many times. Or you can use the one from Crownaudio, or Benchmarks. I created a better one that accepts any impedance values but it's done in Excel and it cannot be attached here for others to use.

You can use any of those calculators mentioned and you will see that 32 W for 95 to 98 dB peak is about right.

The part in your linked video that says 3 dB loss per meter is not good though. The fact is, you will lose 6 dB every time the distance is doubled, but in most rooms, you will have room gain that you need to factor in. In your specific example, it just happens that if you follow their system, the result ended up within the ball park.

Back to your volume -15 scenario again, in that case, your amp will output less than 10 W for sure, subject to conditions I mentioned. In that case, it means you actually listen to less than 95 dB peak from your mmp. I can show you how to figure that out later.
 
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