Hi,
I am seriously new to not just this group but to the entire world of high end sound equipment.
I am looking for advise on a basic book that can get me started.
Most books, mags etc. Assume you already are educated on basic definitions etc.
I'm looking for Audiofyles for Dummies"
I looked on amazon and found " home theatre books"
Not interested in TV and surround sound system.
I'm looking to learn enough to set up my first stereo
With turntable, amp and speakers to start but I am lost in all the specs and and numbers etc.
Any direction would be appreciated especially a good glossary of terms
( eg amplifier, pre- amp etc. )
Tks,
I can't help you with a turntable (a CD player is not an inferior technology, though BTW) but as far as reading numbers:
The specs to look for in amps
FFT Distortion Spectrum - you want mostly 2nd order harmonic distortion if any (2 x the tone) - if it's 1.5 khz tone you might see a bit of 3khz but hopefully 4.5khz, 6khz, 7.5khz distortion is close to the noise floor:
http://www.audioholics.com/reviews/amplifiers/marantz-pm-11s1-integrated-amplifier/FFT-100watt.JPG/image_view_fullscreen
An amp with less crossover distortion (normally higher order harmonic distoriton IE tripling, quintupling etc) supposedly sounds cleaner (IE detailed, less grainy) at low listening levels although 50 years into the development of transistor amps, it isn't nearly a huge problem.
Power into 4 ohms - you should want something that can produce at least 250 watts @ less than 1% THD into a 4 ohm load and possibly more depending on what speakers you choose (or possibly less, it's all a function of your speaker choice). Better amps maintain their voltage no matter the current - this means lower impedance, or more notable phase angle. Better amps also produce more unclipped voltage, of course, which is what leads to subjective "dynamic headroom"
IMD - intermodulation distortion - you won't likely see these in magazine reviews but it's an indicator of poor feedback implementation and can affect subjective sound quality.
Honestly, most of us here don't overly concern ourselves with amplifiers here. Even if they do have differences, they're normally so insignificant that it's almost a waste of time compared to the other 95% of what we hear -
the speakers and their interaction with
the room.
So what to look for in speakers?
1) Smooth off axis plots. These are an indicator of listening position and room sensitivity. I'd say similar performance out to 60 degrees, or maybe even 90 degrees, is fundamentally important
Here is a pretty good one; although it does get a bit ragged above 10khz you have to remember that this is barely an auible octave whereas everything below it is the heart of music:
Here is a bad one; the type of speaker where if you move your head even a bit you'll hear a change in sound. These types of speakers are AKA audiophile speakers and you would not believe the price of this one
So once you've got a smooth horizontal off axis plot, ideally you'd think the vertical plot would be exceptional but I wouldn't say that's true. Here's two speakers with outstanding horizontal off axis plots and you can see the vertical is pretty different:
vs
Which of the above speakers is better? It's not as easy as it seems - as you can see, vertical polar plots of even well designed speakers don't may not look as good, and that means that the majority of speakers will benefit from attenuation of vertical reflections, one way or another. Some companies will use MTM speakers, which intentionally have limited vertical dispersion in the midrange to improve clarity, others will use coaxial drivers, and others just expect you, the owner, to deal with it in your room with all sorts of tricky panels.
- the vertical plane is difficult to judge from measurements alone... auditioning can help.
Frequency Response. "All I need to look for is a straight line, right"? Kind of. From 200hz to 8khz most of us here tend to look for speakers that are +/- 2db (4db window, preferably less). Below the room transition region (close to 500hz), the room greatly infleunces in-room measurements so they may not be reliable as an absolute - below that region you need to look for general trends rather than measured response.
Also bear in mind the difference between a smoothed graph with a huge scale and an unsmoothed, high res graph. The latter tells you a lot more than the former, although it may be prone to the occasional measurement artifact (narrow band peaks and dips) it is ultimately much more indicitave of performance rather than advertising.
Above 8khz, a lot of what we hear is overtones. You don't want a rising response of overtones, and you don't want to overload your room with too much energy, but don't fret over the top octave a lot. Most tweeters are beaming this octave, by the way. All good speakers should be +/- 3db on axis in their passband (bottom of their bass response to 20khz) at least.
Port tuning - you want a speaker that is flat to or even tapering off towards its bottom end limitations, not getting peaky at any frequency. Too much relative port energy is not good for "tight" bass perception.
Sensitivity, Impedance and Phase Angle - the lower the impedance goes below 6 ohms, the further away from +/- 0-30 degrees the phase angle, and the lower the sensitivity, the more your amplifier will make a difference. Impedance is not a flat value - nominal impedance is a worthless spec.
Waterfall Plot / Cumulative Spectral Decay - in some ways you don't need this at all as everything it shows is already "findable" in other measurements, but it does help highlight problems with speakers almost instantly. Things like cabinet resonances as well as driver ringing will be clearly visible on a waterfall plot.
Harmonic Distortion - It's there. How audible? Dunno, but it's normally notably higher than any amp. None of the magazines measure it. Again we want mostly 2nd order harmonics if any. It gets more notable with an increase in...
Power Compression - sure the speaker can sound good at low levels, but what about when it's been running for a while, or when there's a big dynamic sequence? can it handle higher SPLS? Speakers that stay linear at high drive levels are obviously coveted. We don't need concert levels but even lifelike levels can get pretty loud.
Intermodulation Distortion - does it start to sound congested as more and more instruments enter the fray? You want speakers that can do different tones at the same time, of course. Unfortunately, this too is rarely if ever measured.
RT60 - This is a measure of a room's "livelyness". What does a room need to be like to sound good? Good question. Maybe a more lively room sounds more spacious, but accentuates speaker off axis response flaws and thus colors timbre perception. Maybe a more dead room images better and masks speaker flaws, but sounds... well... "like listening to box speakers in a dead room". Maybe your living room is perfectly fine the way it is, and maybe it needs some serious work to even live in, every day
- i would start with the speaker and if the room needs work it needs work. Bass traps are probably the one thing most rooms could probably benefit from, as monopole bass of most speakers loads rooms in such a way that they benefit from some reduced reflected bass energy causing standing waves.
