• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

What I learned from ASR

Putter

Senior Member
Forum Donor
Joined
Sep 23, 2019
Messages
451
Likes
699
Location
Albany, NY USA
The following is intended as a guideline for newbies. There may be agreement on many points, but not all I'm sure.


1. Most electronics are indistinguishable based on sound. The primary differences are based on power and ergonomics.

2. Cables, interconnects, speakers as supplied by the maker are adequate for the purpose. An exception can be made for speaker wire. 16 gauge (of which lamp cord is an example) is the minimum for typical lengths of speaker wire. Larger gauge may be useful for longer runs (say >10 ft). I've broken this rule on occasion with no audible consequences although not checked with blind tests or measurements.

3. Compact disc, DVD, Bluray players all sound the same. Features and ergonomics are the important differences.

4. Similarly, analog to digital conversion and its opposite digital to analog conversion technologies are mature enough that most systems will not audibly change signals. The exceptions are usually intentional.

5. Speakers with good dispersion are preferred by most people. This finding was confirmed by Floyd Toole's research at NRC and Harman. The question is then how to get the best dispersion?
a. Waveguides to optimize horizontal dispersion.
b. Coaxial speakers with the tweeter inside the bass/midrange so that the speaker essentially become a point source. Along those lines non coaxial speakers should place drivers as close as possible to approach a point source.
c. Three way or four way to reduce beaming (narrowing dispersion as the driver reaches its upper limit).

6. There are very few speakers that won't benefit from subwoofer(s). Benefits include lower distortion on the main speakers and in the case of multiple subs, better room response, i.e. fewer dead spots and less boominess due to reinforcement. A single sub may be adequate for a single listener. The general recommendation is 2 subs. Research by Todd Welti of Harman using computer simulations and in room measurements showed 4 subs either at the wall midpoints or in the 4 corners to give the most even response. This is often not practical and to some degree, theoretical since no room will exactly match their experimental room. His alternative is 2 subs at the midpoint between the speakers and the same location on the back wall. Again this might not be practical.

7. The room arguably is the most important component in your playback system and the hardest to alter. The easiest thing to change is speaker placement. In general the best location for speakers is placing the tweeters around eye level which often requires the use of stands. Tilting the speaker can also work well especially for floor standers. Treble can be increased or decreased by the horizonal angle of the speaker. Angling speakers to face the listener will increase the high treble and alternatively angling speakers forward or away from the listener decreases treble.
Placing speakers nearer to the back wall increases bass although it can be uneven. This is particularly true if the speaker is rear ported.

8. A good room eq system (Dirac, Audyssey XT32, Room Eq, etc.) is probably the most effective way to improve sound, but is most effective if the off axis sound of the speakers is a reasonable match for its on axis response. Otherwise it's a bit like whack-a-mole. Fixing the on axis frequency response messes up the off axis response (i.e. reflections) and vice versa.

Room dependent frequencies occur below about 500 hz. Below this frequency standing waves occur causing cancellations and reinforcements of these frequencies particularly in the bass. Not much can be done about the cancellations, but the reinforcements (boominess) can be reduced or eliminated with a good room eq system. The good news is that the cancellations are less obnoxious than the reinforcements.

There is controversy concerning whether to Eq above those frequencies. I lean toward Eq for all frequencies especially for passive speakers. IMO there's nothing wrong with correcting existing flaws in a speaker system. At this point, passive crossovers are still a witches brew of inductors, capacitors, resistors, etc. You wouldn't be happy with electronics that were less than flat so why shouldn't your speakers have a uniform frequency response? In this case, flat means anechoically (i.e.. a special room free from echoes and reverberations. In a regular listening room there will be a gradual drop off in the treble (about 1db/octave as I recall) although the exact shape of the curve is controversial.

Thanks for reading this and thank you for your previous comments.
 
Last edited:

sigbergaudio

Major Contributor
Manufacturer
Forum Donor
Joined
Aug 21, 2020
Messages
1,295
Likes
2,258
Location
Norway
1. With regards to amplifiers it depends on how they react to the speaker load. The difference between electronics isn't non-existant, but often small.

3. DACs and buffer stages etc may sound different, but again small differences.

7. Automatic correction systems are often hit and miss, especially above the Schroeder frequency. It's an advantage if you know how these things works, and can confirm what has happened by measuring with REW or similar. If you want to play it safe, only equalize the low-end (250-300hz and below).

:)
 

Rednaxela

Addicted to Fun and Learning
Joined
Mar 30, 2022
Messages
988
Likes
1,115
Location
NL
Nice list!

Perhaps break up point 7 a bit?

Also, you may be able to put this

There is controversy concerning whether to Eq above those frequencies. I lean toward Eq for all frequencies especially for passive speakers. IMO there's nothing wrong with correcting existing flaws in a speaker system. At this point, passive crossovers are still a witches brew of inductors, capacitors, resistors, etc. You wouldn't be happy with electronics that were less than flat so why shouldn't your speakers? In this case, flat means anechoically (ie. a special room free from echoes and reverberations. In a regular listening room it should have a gradual drop off in the treble (about 1db/octave as I recall) although the exact shape of the curve is controversial.
in a simpler way.

How about:

A speaker’s directivity is an indicator for its EQ-ability. When this is reasonably in order, a practical first step is to EQ its on-axis anechoic HF response to flat, if it isn’t already. Depending on the room and use case this may result in too bright an in-room overall tonal balance, sometimes too dark. Addition of a very broad, usually downward sloping filter is a good way to find a sweet spot between direct and reflected sound tonality. The exact target in-room response depends on too many variables to be formulated in a meaningful way for all use cases, all rooms, all listeners and all speakers. However, with the right amount of caution, inspiration can be drawn from the various target or house curves available on line.

Not sure if it is simpler after all. :facepalm: But maybe you still like it better. :)
 

RHO

Major Contributor
Joined
Nov 20, 2020
Messages
1,172
Likes
1,060
Location
Belgium
9. Topping audio products are unreliable.
My Topping products have been more reliable than my Marantz or Denon or Philips products and cost way less.
 

sq225917

Major Contributor
Joined
Jun 23, 2019
Messages
1,222
Likes
1,346
Replace 'all' with ' mostly' and your about there.

It's all sliding scale, rather than absolute.
 

VMAT4

Addicted to Fun and Learning
Forum Donor
Joined
Oct 25, 2018
Messages
769
Likes
611
Location
South Central Pennsylvania
8. Topping audio products measure the best.
9. Topping audio products are unreliable.
No Topping failures here ( D10, DX3 Pro+).
 

MarcosCh

Major Contributor
Joined
Apr 10, 2021
Messages
1,494
Likes
1,133
Wow yeah, that's pretty much it.
Actually if this website would have a sort of guide wiki with some articles detailing points 1 to 7 with some explanations and measurements easy to understand and maybe a few guides "how to integrate a sub", "how to do room correction", "how to choose your amplifier" etc. beginners level It would be super valuable.
 

Rednaxela

Addicted to Fun and Learning
Joined
Mar 30, 2022
Messages
988
Likes
1,115
Location
NL
Actually if this website would have a sort of guide wiki with some articles detailing points 1 to 7 with some explanations and measurements easy to understand and maybe a few guides "how to integrate a sub", "how to do room correction", "how to choose your amplifier" etc. beginners level It would be super valuable.
There are many stickies for that already right?
 

MarcosCh

Major Contributor
Joined
Apr 10, 2021
Messages
1,494
Likes
1,133
There are many stickies for that already right?
Yes, true, maybe it is just a matter of clean up and compile the most basic and complete ones.
(example: @amirm 's room measurement tutorial that leaves you after chapter 2 thinking... "that's it? where is the rest? :-/" Or at the oposite side of things @mdsimon2 excellent camilladsp tutorial, that starts to be a reference in the internet, but is not even sticky here...)
 
Last edited:

Cote Dazur

Senior Member
Joined
Feb 25, 2022
Messages
313
Likes
279
Nice OP, resumes the situation pretty well, most here following a different set of rules driven from measurements centric observations for better or for worse.

Room dependent frequencies occur below about 500 hz
Do you mean that when moving speakers in a room, the only variations in sound is about what occurs below 500Hz.
My experience is that totally different curves are shown when moving a speaker or even the microphone (seating position) just a few inches at frequency well above 500Hz, all the way up.
Similarly the sound in my different speakers and different room ,changes drastically and not just the below 500hz, when moving speakers and listening chair, even when moving just the head.
Variation below Schroeder are to be treated differently, but it does not mean nothing happens in relation to room affecting sound higher up, as just listening or measuring will show.
 
Last edited:

Tom C

Major Contributor
Forum Donor
Joined
Jun 16, 2019
Messages
1,105
Likes
961
Location
USA
8. Topping audio products measure the best.
9. Topping audio products are unreliable.
Topping DAC x 3 in my house. No issues whatsoever, so far. Perfectly reliable.
 
OP
P

Putter

Senior Member
Forum Donor
Joined
Sep 23, 2019
Messages
451
Likes
699
Location
Albany, NY USA
Nice OP, resumes the situation here pretty well, most following a different set of rules driven from measurements centric observations for better of for worse.


Do you mean that when moving speakers in a room, the only variations in sound is about what occurs below 500Hz.
My experience is that totally different curves are shown when moving a speaker or even the microphone (seating position) just a few inches at frequency well above 500Hz, all the way up.
Similarly the sound in my different speakers and different room ,changes drastically and not just the below 500hz, when moving speakers and listening chair, even when moving just the head.
Variation below schroeder are to be treated differently, but it does not mean nothing happens in relation to room affecting sound higher up, as just listening or measuring will show.
I didn't really deal with non Eq ways of improving speakers such as placement on stands to raise them up to ear height, acoustic paneling, more furnishing, speaker placement nearer and farther away from walls or my favorite, which is angling a speaker below a monitor up toward the listener so it gives the illusion of being at the same height as the other bookshelves. I believe that I started to talk about room effects in a previous revision and hit the wrong key and it disappeared.

This is starting to become a beginners guide vs. what I learned from ASR which were that all connects and speaker wires will work as long as they meet some minimum requirements, that amps usually sound the same within their power outputs and most interesting that you can look at a conventional speaker and determine at a glance whether it is likely to have good dispersion by being coaxial or 3 way or having a wave guide or placing drivers close together. This doesn't tell if it has a flat frequency response although it may indicate if it can be Eq'ed to flat. I expect I'll do another revision dealing with room issues.
 

NiagaraPete

Major Contributor
Forum Donor
Joined
Jun 23, 2021
Messages
1,685
Likes
1,303
Location
Canada

Vacceo

Major Contributor
Joined
Mar 9, 2022
Messages
1,767
Likes
1,786
Not all transports are the same in my experience.
Some are turbo expensive, some are not. Indeed they´re not the same.

I have used a number of them, mine or others, and I have listened nothing different being all the rest of the system equal.
 
Last edited:
Top Bottom