Manufacturer's taking consumers for Big Big Ride - A real case study

Audiolab 6000N Play

flanker.r

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I started this tread as a separate one following a user reporting about the lack of performance between active and passive subs. Perceived effect is not due to the inherent advantages of active over passive designs but due to manufacturers taking consumers for a big big ride

Any HT receiver would not be able to sufficiently power a subwoofer. A HT AV receiver has just maybe one power supply transformer (higher end models 2 at the most). These provide power to the ADC and DAC, dolby, dtx processors, displays, multitude of relays inside, 5 speakers and one sub woofer.

Sub woofers require lots of power. The amps inside a AV receiver can hardly power a subwoofer adequately which explains the lack of performance you face. I do not know much about HT receivers (but have designed sub-woofers for music extensively) but when I looked up the net for specs of onkyo 3100 this is the model that the user says has experience and felt passives offered poorer performance - it says the output is 130 W. Now please see this link below for specs of the unit and come back to this message

Onkyo HT-S3100 - 5.1-Channel Receiver/ Speaker Package | Model Information | Onkyo USA Home Theater Products

What the manufacturer says is that the amp can supply the front, surround and centers with 115 W each and does not talk of sub-woofer output here (i.e. the amp section). Start looking at the ambiguities now.

1. Is this the RMS power? No mention.

2. Nowhere does he say if this output would be maintained if all channels (front, centre, rear, subs, etc) are driven simultaneously. Also even for individual channels he says output is based on a 1kh reference frequency. As you know at any point of time you will have multiple frequencies in music (even movies) multiple instruments, voices, sound effects and not to mention their harmonics). So it is unlikely the amp can even power a single channel with complete bandwidth (20-20k)

3. Next take THD. 0.9% is very very high (0.01% is accepted as min in solid state audiophile equipment). And even that Onkyo says is 0.9% of rated power. Now whats that new term and what is the actual rated power. Keep searching it leads you to point 1 and 2 again. Without them answered this serves no purpose.

4. In speaker section look at claimed subwoofer frequency response. They claim 30 hz to 150 hz. Are they claiming a ruler flat frequency response. For 1 W input will the speaker produce 83 db/m (their claimed efficiency for sub) at 30 hz and and 150hz. It is almost impossible for a 8 sub to go down as low as 30 hz. 12 subs find it difficult. To claim that an 8 goes down to 30hz and maintains claimed SPL with ruler flat accuracy is a blatant lie and such a cheap claim that not even a college student who uses a 8 as sub in an earthen pot would utter this. 5 stars to Onkyo for having the guts to do this

5.Next look at the efficiency of the sub. 83 db/w/m. lets say sub is in the corner of a room and your listening position is 2 m away from it (very common) the efficiency of the sub is only 71 db/w/m now (remember 6db drop per meter). Power the puny amp with all channels driven and wait till we hear. If the sub-woofer can be heard its a remarkable achievement. Dont even think of performance or bass extension from these units.

This is the real reason for lack of performance by passive subs. Bad drivers, incorrect specs, exaggerated claims, puny amps and lies, lies and more lies

Buyers beware !. Understand the specs. If you dont, ask people who know about these things. It is better to be ignorant and ask friends that get fooled by salesmen and unscrupulous marketers.
 

Muthusami S

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I started this tread as a separate one following a user reporting about the lack of performance between active and passive subs. Perceived effect is not due to the inherent advantages of active over passive designs but due to manufacturers taking consumers for a big big ride

Any HT receiver would not be able to sufficiently power a subwoofer. A HT AV receiver has just maybe one power supply transformer (higher end models 2 at the most). These provide power to the ADC and DAC, dolby, dtx processors, displays, multitude of relays inside, 5 speakers and one sub woofer.

Sub woofers require lots of power. The amps inside a AV receiver can hardly power a subwoofer adequately which explains the lack of performance you face. I do not know much about HT receivers (but have designed sub-woofers for music extensively) but when I looked up the net for specs of onkyo 3100 this is the model that the user says has experience and felt passives offered poorer performance - it says the output is 130 W. Now please see this link below for specs of the unit and come back to this message

Onkyo HT-S3100 - 5.1-Channel Receiver/ Speaker Package | Model Information | Onkyo USA Home Theater Products

What the manufacturer says is that the amp can supply the front, surround and centers with 115 W each and does not talk of sub-woofer output here (i.e. the amp section). Start looking at the ambiguities now.

1. Is this the RMS power? No mention.

2. Nowhere does he say if this output would be maintained if all channels (front, centre, rear, subs, etc) are driven simultaneously. Also even for individual channels he says output is based on a 1kh reference frequency. As you know at any point of time you will have multiple frequencies in music (even movies) multiple instruments, voices, sound effects and not to mention their harmonics). So it is unlikely the amp can even power a single channel with complete bandwidth (20-20k)

3. Next take THD. 0.9% is very very high (0.01% is accepted as min in solid state audiophile equipment). And even that Onkyo says is 0.9% of rated power. Now whats that new term and what is the actual rated power. Keep searching it leads you to point 1 and 2 again. Without them answered this serves no purpose.

4. In speaker section look at claimed subwoofer frequency response. They claim 30 hz to 150 hz. Are they claiming a ruler flat frequency response. For 1 W input will the speaker produce 83 db/m (their claimed efficiency for sub) at 30 hz and and 150hz. It is almost impossible for a 8 sub to go down as low as 30 hz. 12 subs find it difficult. To claim that an 8 goes down to 30hz and maintains claimed SPL with ruler flat accuracy is a blatant lie and such a cheap claim that not even a college student who uses a 8 as sub in an earthen pot would utter this. 5 stars to Onkyo for having the guts to do this

5.Next look at the efficiency of the sub. 83 db/w/m. lets say sub is in the corner of a room and your listening position is 2 m away from it (very common) the efficiency of the sub is only 71 db/w/m now (remember 6db drop per meter). Power the puny amp with all channels driven and wait till we hear. If the sub-woofer can be heard its a remarkable achievement. Dont even think of performance or bass extension from these units.

This is the real reason for lack of performance by passive subs. Bad drivers, incorrect specs, exaggerated claims, puny amps and lies, lies and more lies

Buyers beware !. Understand the specs. If you dont, ask people who know about these things. It is better to be ignorant and ask friends that get fooled by salesmen and unscrupulous marketers.

Very well written Flanker. Even though the points were clearly mentioned, most people have brand loyalty and decide based on reviews; not by auditioning. Most of the time, people buy with ears shut and eyes open; I mean preference is based on aesthetics.

Regards,
Muthusami. S
 
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moserw

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Very well written Flanker. Even though the points were clearly mentioned, most people have brand loyalty and decide based on reviews; not by auditioning. Most of the time, people buy with ears shut and eyes open; I mean preference is based on aesthetics.

Regards,
Muthusami. S

Totally agree with you Muthu, but to some looks matter the most. I cannot really argue with my wife especially and to her the next set of speakers sound the same as the previous set. Its not that she has bad "ears", just not interested or passionate about sound like I am and for her the looks quotient is more important than performance while I don't bother about looks as long as it sounds great.
 
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Muthusami S

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Totally agree with you Muthu, but to some looks matter the most. I cannot really argue with my wife especially and to her the next set of speakers sound the same as the previous set. Its not that she has bad "ears", just not interested or passionate about sound like I am and for her the looks quotient is more important than performance while I don't bother about looks as long as it sounds great.

Yes. I agree that aesthetics is also important but it can be considered only after the sound quality.
 
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square_wave

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Flanker,
This is a known fact among audiophiles. No one who is serious about his sound go for these all-in-one boxes. This is more a case of demand driving the business. People want an all-in-one box under 50k. The brands then make some well informed and researched compromises to manufacture these cost effective boxes. For example, never during a movie will you have all speakers firing at full volume.

Consider this:
The least expensive (decent quality) stereo (2-Channel) power amp costs around 40k these days. I am talking about a Nad, Rotel etc This is how much it costs to manufacture something decent and get it to the market, manage overheads, advertising and make a decent profit for the brand.
Now if you want six of these channels, a pre-processor and all the other glitz and lights and three transformers plus all the other connections and stuff needed for HT and a thick shiny faceplate, it will cost a bomb. If you maintain the same uncompromising quality throughout, I am sure you cannot sell it for less than 2 lakh.

Now if a serious manufacturer really wants to do it, it is not possible to keep it in one box. There a hundreds of quality related issues related to electrical/mechanical isolation, interference of various kinds, need for separate power supply for the processor section and power section and so on a so forth I can go on here..
That is why you have separates :D Go for them if you dont want to compromise.
 
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nitinbose

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Hi,

The facts presented are quite true with most manufacturers. An HT a/v manufacturer often "over subscribes" the amp, i.e. the assumption is that when playing a movie, at no given time, the track would have audio on all the channels.

Hence good manufacturers take into consideration that there will be audio on the left, right & center channels at all given times and have a powered subwoofer. In this case the point to note is the power input to the system must be atleast double the output power of the above mentioned three channels.

However many manufacturers go as far as considering only one channel at a time!! e.g. in Sony home theater systems!! That's quite an ecomomizec system and one should not even look at such a product.
 
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