Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Danijel Foler]

Teaching on my topic "Why is active speakers underpowered???"
https://forums.prosoundweb.com/index.php/topic,175199.0.html
Many things is now more understandable to me. Thanks

Now, I want to discuss about some other sound "definition", amount off sound. Maybe is amount wrong word, this is in my head but I cant find some better word. Be free to correct this.

Example from two events.
One time I find myself in front of line array. Around 8 box per side, something like KF760, with some subs bellow. Sound volume is not to high BUT amount of sound is fantastic. BIG BIG. Much more space have same coverage, everywhere is enough sound. More crowd is around me, no drop in amount of sound. Like PA can produce enough sound per listener Great experience.
In contra, I find myself in front of one powerful speaker, same volume, same distance...But experience is nowhere as sound from bigger line array. Sound is poor, thin, lack coverage in space with no enough sound.

We can buy PA system with more speakers/drivers, with less but more SPL capable speakers/drivers, with bigger or smaller drivers. Example, one 18" horn loaded subwoofer or 2x18"x2 box subwoofers. Four horn loaded 1kW tops with single 12" inside or 16x 250W tops with 10"x1"...etc...I don't know how horn can "expand" amount of created sound from installed driver?!

From above event examples "more" drivers move much larger air in space, producing "more amount of sound" with same SPL. Do I think in wrong direction or my ears is cheat in some way??? Can more speakers cover more people or I think in wrong direction???

Analogy. Dozer with big blade and with smaller one. Dozer speed is sound volume, land moved is "amount" of sound. With big blade attached dozer can move 5m3 land and smaller one can move 2m3 per second.

[Keith Broughton]

You have not included speaker directivity in your examples.
I have heard line arrays with many drivers not cover the distance, or sound as good,  as a horn loaded speaker with fewer drivers.
The more drivers in a speaker system, the harder it is to reduce the problems created with many sources of sound.
The more sources of sound spread out in a venue , the harder it is to time align.
The system requirements for reproducing music may be a bit different that reproducing voice only. 
As usual, "it depends" on what tools are best for the job you are trying to do.

[Ivan Beaver]

There are different things "at play".

The more speakers you use, the worse the sound quality will be, due to interference between the different drivers, arriving at you at different times (combfiltering).

There are all kinds of different things that can affect the "sound experience".  The quality of sound source, the alignment of the sound system, the actual mix etc.

Without having everything the same, except the loudspeakers, it can be very hard to easily tell which is better.

And "better" depends on what people want/are looking for.

Line arrays were a good step forward in sound quality from the previous ways of simply stacking loudspeakers (but they still have interference).  But for some types of music, there is nothing like the "sonic experience" of a huge wall of loudspeakers all interfering with each other and just pushing air onto the crowd.  But for other types of music, that can be a bad thing.

Looking for a simple answer can get into very technical discussions, as well as personal preference, and "sonic experience" opinions.

So don't expect a simple easy answer.

As a general rule, ONE loudspeaker, by any manufacturer is always going to sound better than multiples, no matter what model or brand.  But it may not get loud enough, and sound quality may not be what the listener is looking for.  Some people do not like a nice clean sound, they like distortions, interference etc, because that is what they "think" it is supposed to sound like, because of their experience.  A clean natural sound does not sound "right" to them.  They look for the "sound" of a PA system.

Just like some people like more treble and some people like more bass, sound opinions vary.

[Danijel Foler]

How horn can add to "more" sound?
Example is 18" in bas reflex and same driver in big horn. Will driver in horn produce more sound?

[Jim McKeveny]

How horn can add to "more" sound?
Example is 18" in bas reflex and same driver in big horn. Will driver in horn produce more sound?

Less loss = More sound is the simple explanation, (of course fraught with the multitude of limits and qualifiers that accompany all "simple" scientific statements)... Both the reflex and bass horn mitigate loss. The reflex uses a portion of the rearward cone energy to augment the forward response (with limits & costs), and a horn reduces transfer losses from the immediate near-cone field to lower impedance "free" air environment (with limits & costs).

[Chris Hindle]

How horn can add to "more" sound?
Example is 18" in bas reflex and same driver in big horn. Will driver in horn produce more sound?

It's not that simple.
Both 18's driven with the same power...
The Horn will usually be louder than the reflex box. so more sound.
The Horn (unless MASSIVE) will not go as low as the reflex box, so less sound..
With sound, you have to make compromises with everything you do.
Big horn are heavy, and take a LOT of space to store, move, and operate.
Reflex boxes are more compact, easier to move.
Like Ivan is fond of saying.. "It Depends"
Chris.

[Brian Jojade]

Simple answer: More speakers is never 'better' from a pure quality aspect.  However, more speakers can often be better coverage as you can have more control where the sound goes.  Anywhere 2 drivers are overlapping in coverage, there is potential for interference.  If better coverage is more important than the sound degradation of interference, then more drivers is the right answer.

Horns can be used to change the operating characteristics of a driver. How they appear to amplify sound is a whole bunch of physics.  This is never without trade-offs though.  Frequency response can change, directionality can change, etc.

It all comes down to the decisions of the engineers designing the system which is a better choice for the particular application.  In audio, there is never ONE right answer.  Getting a formula to make the decision includes sound quality, physical size and weight of boxes, available positions to place boxes, coverage pattern desired, and of course, cost.  With that many variables, there are often many acceptable solutions to get the job done.

[Ivan Beaver]

How horn can add to "more" sound?
Example is 18" in bas reflex and same driver in big horn. Will driver in horn produce more sound?

It is not as simple as that.

A horn can add a lot of sensitivity (loudness for a given input level) to a driver, IF, and that is often a big "if", it is designed properly.

If the driver and horn don't match up, you will not get as much output as you could.

A horn will only "give free sound intensity" over a limited freq range.  Outside of that range, it will not be able to provide the proper loading to the air.

So if all you are looking at is " total loudness", then a properly horn loaded driver will be louder.  But maybe not at the freq that you want it to be.  Or it might be.

There is a lot more involved.

There is loudness, and then there is evenness, and then there is quality of sound, and then there is character of sound and so forth.

If all you want is loud, run a piece of metal through a circular saw, it will hurt your ears.  But some people want more than just "LOUD!".

Some people like distortion, others like clean.  Some prefer extended highs, some prefer extended lows.  Some like a natural uncolored sound, some like for the sound system to have a distinct sound character.

[Jim McKeveny]

Less loss = More sound is the simple explanation, (of course fraught with the multitude of limits and qualifiers that accompany all "simple" scientific statements)...

"Buy low, sell high" is a simple distillation of market success. "Less loss=more sound" is a valid starting point for discussion about post-cone enclosure/environment, no? (Let us assume we are not talking about single-note resonators).

[Luke Geis]

I like to think of the free space in which we listen to a speaker/s as an impedance matching/coupling device.

The air has a range of impedance ( sea level vs. the tree line, or low humidity vs. high humidity ) and the speaker is trying to push through this resistance. If you can imagine a raw speaker suspended in space, you can see how only its cone would be the driver that tries to push through the resistance of air. Not very effective. So how do you make that small speaker seem bigger and more effectively push sound through the air? You add a baffle, a horn, or some other device to it that changes how that raw speaker couples to the air. A horn has a significantly bigger area that interfaces with the air than the raw driver does. This is why horns work. They increase the pistonic effect that the raw driver has on the air. I.E. a horn increases the sensitivity of the speaker by increasing its ability to convert voltage into acoustic output.

Now imagine a bunch of relatively small speakers, which on their own would do little to move air. When you have a wall of these speakers, it does effectively the same thing as a horn. It increases the sensitivity of the speakers so that they are more effective at converting voltage into acoustic output. This is why having two speakers with the same wattage each is +3db louder than only one speaker. Now every time you double the number of speakers, you increase the sensitivity of the system by +3db. This as you can see has a point of diminishing returns. A nice upside to having a BUNCH of speakers in a line is that you can increase coverage at the cost of coherence and sensitivity in certain " zones ". A Line Array system works by using a combination of divergence shading ( the angle difference between each box ) and amplitude shading ( the volume difference between one or more boxes in the array ). The angle and volume of the different boxes in the line allow you to control, to a degree, the vertical coverage of the array. In the case of clusters of speakers like the old RAT Trap, it has somewhat of a similar thing going for it. It allows control over coverage at the cost of coherence and sensitivity.

That is a rough simplification of how a speaker system works in air and some of the capabilities. So what about a single speaker that simply has more volume or coverage?

I don't think you can ever really replace the experience of a Line Array system that is well-tuned and sorted by any single speaker system. At least not the visceral part of it. I feel that the quality of sound that is provided from a Point Source system makes a LA system sound like a Fischer Price toy in comparison, but without that spank in the face that a LA has. Point Source systems have a softness and subtlety to them that is very linear when set up correctly. The sound simply reaches you at a level that is much less aggressive. As can be imagined, the sound isn't being thrust upon you by 100+ different drivers. The detail and accuracy is so precise and coherent that you are not hearing the same sound amplified from 100 drivers all reaching you at a different time. You hear the direct sound only a couple of times, not 100 times in a very short period of time. That is why PS and LA systems sound so different. One is more exact and technically correct, while the other bludgeons you to death with a cacophony of sound from 100's of sources.

Unfortunately, PS systems don't currently excel at the long-distance aspect of " coverage ". They are bound by the laws of physics and LA systems ( properly deployed ) can beat those physics by about +3db over the same distance ( in general ). In your case, I think you just like the impact that a LA system provides. PS systems will spank you just as much in near field listening, but as you get further away even if the volume could be made the same, they just don't hit you the same. Which I think is better myself. It sounds better too.

[ProSoundWeb Community]