HIFI - WHAT TO LOOK FOR?

Discussion in 'Hi-Fi Stereo Systems & Separates' started by Rob Sinden, Dec 17, 2016.

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  1. Rob Sinden

    Rob Sinden
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    If you are buying a performance car you would expect to know its top speed, how quickly it can accelerate to 60mph and its power. All these figures give you an understanding of the performance you can expect and are given reasonably accurately by the manufacturers.

    The same is not true in the hifi world.

    Hifi systems sound and measure inaccurate and so their specifications are typically not given or presented in a meaningless way.

    I believe that if customers understood more about the systems they were considering and the specifications they can expect from them, they would make very different choices about the systems they buy.

    So, what information should you be looking for?

    Speaker Frequency Response: Any digital source or amplifier will play all the frequencies in music you can hear. This is expressed as 20Hz – 20,000 Hz (or 20kHz) and is what a speaker system should be able to reproduce.

    20,000 Hz is the highest frequencies anyone can hear and all speakers will play these frequencies. 20Hz is regarded as the lowest frequencies people can hear. Its these lower notes that 99% of loudspeakers cannot reproduce.

    Speaker Efficiency: The efficiency of a speaker tells you how loud it will play with 1 watt of power. Most speakers are around 90db efficient. For bigger rooms or where more output is required a more efficient speaker is required. A 93db efficient speaker will play twice as loud with 1 watt than a 90db.

    In Room Response: Perhaps the most critical measurement in home audio is how accurate your system is in your room, sitting where you listen to it?

    An audio system will sound very different when placed in different rooms because of the effect of your rooms acoustics.

    For example, a large floor standing speaker may sound great in a medium sized listening room. The same speaker placed in a small room will typically sound boomy and bass heavy. Placed in a large room the same speakers will lack bass and so sound too bright.

    Because your room has such a huge impact on the response of your system, this critical figure can’t be given. What should be considered is some way of removing the changes your room makes to the sound of your system.

    In an ideal world you should be aiming for a system that plays down to 20Hz with as little variation from note to note as possible.


    This video from the Godfather of Sound Reproduction in the home, Floyd Toole reveals what a nonsense the information speaker manufacturers provide. The video is 70 minutes long but is a packed with the most relevant, revealing information about speakers you’ll ever hear.

    Some of myths it debunks and advice it gives are: -

    - How differently people rate speakers when they can see them
    - How closely measured performance matches perceived sound quality
    - How worthless the specification that speaker manufacturers give are
    - How bad the performance is of many highly regarded expensive speakers
    - How badly audio reviewers are in blind listening tests
    - How critical bass quality and level is to overall sound quality

    Floyd Toole - Sound reproduction – art...
     
  2. cosmicma

    cosmicma
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    just watched it

    some interesting points but general conclusion is he's basically advertising harman products
     
  3. Rob Sinden

    Rob Sinden
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    I do not sell JBL/Harman products.

    JBL/Harman is a competitor of mine.

    Floyd Toole is retired.

    He has not posted this video to try and sell JBL/Harman products but to try and teach people about his passion of reproducing music and film in a life like way.

    If you think this is an ad for JBL/HK products I think you should watch the video again.
     
  4. Stinger69

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    I think that for a speaker to be twice as loud for any given power, it would have to be 10db more sensitive. A 90db vs a 93db speaker will require twice the input power to produce the same output, but doing so will not produce twice the perceived volume.

    There's a pretty good link below that explains this:

    Loudness volume doubling sound level change factor of perceived loudness decibel scale log compare intensities formula calculate power level noise levels volume logarithm dependence three four fold loudness sound - by what factor does level decrease dependence comparison decibel levels 3 dBSPL 6 dB 10 db double voltage sound pressure audio sound intensity acoustic power formula relationship decibels dB twice as loud two times double distance half level dependence auditory loudness formula sound noise loudness sound pressure intensity a-weighted twice as loud increase decrease SPL - sengpielaudio Sengpiel Berlin
     
  5. Rob Sinden

    Rob Sinden
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    That makes sense! That you for your response.
     
  6. cosmicma

    cosmicma
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    i wasn't suggesting you posted this as an advert i was saying the lecture came forward as an advert even though he is retired

    there was quite a bit of reference to Harman M2's along with other Harman products within the lecture, overall i found the lecture interesting
    the part about how a speaker behaved within different room sizes and how they could predict this and using room equalisation doesn't help in a lot of circumstances more or less confirmed some of my own thoughts about the subject
     
  7. Arcam_boy

    Arcam_boy
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    Its all relative though I guess.

    Those specs are great but how many people actual bother/care about them?

    Obviously the efficiency aspect is quite confusing for most as even you've quoted the wrong figures, Rob, and you've been in the game years!

    As for the 20Hz - 20Khz subject, I'm sure that's great but I've heard systems that can do this and sound crap and systems that can't and sound stunning - Kef Blades/Ref 5/ MA Plat 300/500 can't reach down to 20Hz according to the manufacturer specs and yet sound sublime!

    As I've discussed with you before - take a system 2x MK300's / 1 x sub / lyngdorf TDA1 - 2170 to something like the Hifi Wigwam show and let hifi enthusiasts hear a system they'd normally dismiss, if it really does all the above then you may get a few new customers off the back of it too!!
     
  8. BlueWizard

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    A couple of points to consider, or at least in my opinion.

    In a music system, 20hz to 20khz is a bit unrealistic from a single full range speaker. In my own experiments, I've found that most sound under about 28hz, is not a tone or note at all, but rather just the fuff-fuff-fuff of the driver pumping. From floorstanding, if you can get down in the range of 30hz, even 30hz at -6db, it should provide very satisfying results, and is far more realistic to achieve from a single speaker pair.

    Also, make a distinction between Perceived Bass and Rated Bass. Many speakers with modest rated bass, can have very intense perceived bass, and those with modest perceived bass can have very deep rated bass. Keep in mind that deeper does not necessarily mean louder.

    But the key point I want to bring up is - Suitability to Purpose. You and your room carry just as much weight as any other factor in the decision of what to buy. You must first ask - What is it I want to do, and is what I want to do realistic? Both realistic within the stated budget and within the context of the room.

    To use an extreme example, you don't throw a Rave in an auditorium using a pair of bookshelf speakers. Equally, you don't put a large PA system in a 10ft x 10ft bedroom. What I need on my computer is very different than the speakers I have on my main system.

    So, you must understand your circumstances and what is realistically achievable within the context of those circumstances and your budget. If you are expecting 20hz from a single full range speakers, then expect to be disappointed. Those speakers are extremely few and far between, and they tend to be large and on the expensive side.

    Generally, in a floorstanding speakers, I try to make sure I say under 40hz on the low end. Though I try to get as close to 30hz as possible. For a bookshelf speaker, under 50hz on the low end, but again, I try to get as close to 40hz as possible, which is about the lowest you can expect from a bookshelf speaker.

    But again suitability to purpose comes into play. Because of my circumstances, Floorstanding speakers on my computer are unrealistic, though I have seen others pull it off. Equally, and unique to me, Bookshelf are out of the question on my main Stereo system. Though at some point circumstance might force me to switch to Bookshelf for my main system. But short of being forced into the alternative, I'm always going to have floorstanding in my main system.

    Keep in mind this is for a Music system. For a Movies system, though floorstanding serve me well without a Sub, most people are going to want a Sub for movies. Mostly what you get from movies that are very deep are shock waves, not notes or tones. A Subwoofer can certainly add impact to a Movie sound track.

    While many people do have Subs for Music systems, it seems an unnecessary complication and expense to me. Again, that's just me, based on my preferences and priorities.

    So, back to the point - You can't get what you want until you know what you want. And what that means is, you need a system that suits your circumstances, goals, and budget. Your preferences have to be realistically achievable within that budget and within those circumstances.

    What is a good system in generally might not be suitable to your circumstances, so you need to work on the best possible system for YOU in your circumstances.

    Steve/bluewizard
     
  9. phil t

    phil t
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    Thing is, you'll know all of the above, but not know how the car handles on a twisty and wet B road. Not know how firm the suspension is. Not know what it's like to live with on a cold winters morning, etc, etc.

    Numbers and figures only take you so far, but don't and can't (within the confines of this thread) define emotion, pleasure, etc.

    I didn't buy any of my kit (MF a3.2cd MF a5 integrated Focal 1007s) based upon figures. Nor did I buy it based upon reviews.
     
  10. lindsayt

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    I have speakers that are pretty flat down to 20 hz.

    They are huge 1960's EV corner horns.

    Their strongest area is the midrange focus, clarity, dynamics. All things for which there are no meaningful measurements. And all things that are very apparent on comparative listening tests.



    When it comes to hi-fi, there are only 3 specifications that I take any notice of when deciding whether to buy or not:

    1 Initial selling price. A million yen or more is good.

    2 Weight. Over 70 kgs for speakers is good. Over 20 kgs for amplifiers and over 15 kgs for turntables.

    3 Selling price now. Under £500 is good. Failing that, £500 less than the current going rate is OK.
     

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