THREAD: Do All Speakers Sound Alike Once They Are EQ'd?

This thread started with a simple myth that all loudspeakers sound alike once they are

equalized. This thread takes a careful look at why that's simply not true.

I've seen a very interesting thing regarding speakers--if you set up

the "top name" speakers side by side and adjust them (via EQ) to have

the same response, they ALL sound the same! This of course assumes all

of the cabs are of similar design (i.e., one isn't a subwoofer and one

isn't a dual concentric...)

Interesting also to note that the six biggest speaker companies all

use the same high frequency driver in their cabs in several of their

designs. Their excuse? It costs a lot to research to make a good

driver--if they can use what's already out there they save money, they

can charge less, and you're happy. Hm. Makes you wonder.

Again, this is not to say that _I_ don't have a favorite speaker,

either!

Blake Engel (All Church Sound; Chicago, IL)

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Blake,

I can't say that I agree with you fully on that one. I've attended well

managed speaker shoot-outs as well. We even held a shoot-out at one of

our Soundcheck conferences. I'll agree that if two loudspeakers are both

designed great to begin with, and if they choose from the same pool of

OEM driver manufacturers, that it's likely they'll sound quite similar -

once they've been voiced and signal-aligned (which is what some

manufacturers endeavor to accomplish with their accompanying processors).

But that's only part of the issue. If you start to look at the speakers

carefully, you'll find that their polar patterns can be immensely

different. And how they interact when clustered together is a huge issue

with certain devices.

Several years ago, there were several boxes offered from various

manufacturers that sounded great on their own. But when designers started

packing them into clusters they found out that the boxes were non-arrayable!

When arrayed, they sprayed knife-edge lobes of energy at various

frequencies all over the place.(For the uninitiated, you'll know your

cluster has a lobing problem if you walk with a mic across the stage

under the cluster and find a fairly narrow area in which the mic is very

susceptible to feedback. There could be several of these areas on stage.

If you're in a spot where it feeds back easily, and you move just a couple

of feet to the left or the right on the stage and the feedback disappears,

it's entirely likely that your cluster has a lobing problem. You may also

hear strong, narrow phase cancellation problems at high frequencies as you

walk across the area up near the front of the seating sections.)

Now, it's also likely that even very well-behaved speakers of current

design can pose lobing problems if they are not properly arrayed. And that's

a whole other conversation.

And there are still manufacturers who make their own HF drivers. That's

how Renkus-Heinz got started in the industry. Community is proud of the fact

that they build just about everything they use in-house except grow their

own trees for the cabinets. (On a side note, their plant is located just a

couple of miles off the approach path to Philadelphia International Airport,

and the device they use to create their magnets is listed on the flight

charts published by the FAA as a magnetic disturbance. It's way cool!)

It goes back to the design issue we've been discussing, only on a different

level. Industry leaders like Ralph Heinz at Renkus-Heinz, Bruce Howze and

John Wiggins at Community, Kenton Forsythe and David Gunness at EAW, and

Jay Mitchell at Frazier, just to mention a few, have done a phenomenal job

at understanding and pushing God's laws of physics to the limits as we

understand them so far. Craig Janssen found some information in a book

written many, many years ago that led him to discover an effective way to

allow pattern control at low frequencies without using enormous LF horns

to guide the energy. Craig is a consultant, not a manufacturer, but none

of the manufacturers built what he felt he needed for his designs, so God

led him to that discovery (and EAW got the patent). And while we're at it,

let's not slight Peavey. You might be surprised to discover that Peavey

is the single largest owner of TEF analyzers in the industry. Their lead

designer, Charlie Hughes, knows his stuff.

There's also an issue of phase coherent wavefront. Now, even that term can

be misused. But for example, it has been believed for years that one

couldn't deliver high frequency energy over a great distance simply due to

the effect of air absorption at high frequencies. But Renkus-Heinz has a

box that defies that logic, and it is believed that the reason it can do

so is due to it's extremely close physical signal alignment within the box.

All of those companies design cabinets for specific reasons. Many are in

response to specific requests from consultants and other customers. Some

are in response to what each company believes their customers need, and

how far they believe they can push the physics. There was a day when,

if you wanted a LOUD loudspeaker, you had to buy a BIG loudspeaker. Now

you can buy several loudspeakers that are exceptionally small by comparison,

but that will easily reach the levels of some of those old large boxes,

and exceed their sound quality at the same time.

Okay, okay, 'nuff said. That should open up an interesting sortie. To

quote a friend, fire at will.

Curt Taipale (Taipale Media Systems, Inc.)

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Curt,

Regarding the speaker shoot-out, I agree that some speakers are arrayable,

and others are not. I was simply stating that if you EQ them, voice them,

and (signal)-align them, (a SINGLE speaker) they will sound identical.

Whenever you use more than one speaker you have trouble with lobing and

such. That's a given.

My message was directed a bit more toward the church that wanted (4)

speakers to cover the room--I assumed the (4) would be several feet apart

(to prevent or reduce comb filtering)...

Blake Engel (All Church Sound; Chicago, IL)

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Blake -

<"I've seen a very interesting thing regarding speakers--if you set

up the "top name" speakers side by side and adjust them (via EQ)

to have the same response, they ALL sound the same!">

Nonsense! They might well sound similar, but I bet a double blind test

would still allow you in most cases to tell one from the other. There is

so much more to the sound of a speaker than just on axis frequency

response, (like distortion and polar response, among many others) that

such a commentis laughable.

<"Interesting also to note that the six biggest speaker companies

all use the same high frequency driver in their cabs in several of

their designs.">

I wonder who you consider to be the "six biggest speaker companies". EAW

buys their drivers, Renkus Heinz makes some and buys some, Community makes

some and buys some, EVI (EV and Altec) make all of theirs, as does JBL.

In my book these would be the big six of professional sound reinforcement.

Even if all of them bought the same driver, it would be because it was

so good that they couldn't find something better!

Ray Rayburn (Peak Audio; Boulder, CO)

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Ray--

Go ahead and have someone set up a double-blind speaker shootout.

Regarding the six biggest companies using the same drivers--didn't I SAY

they felt one specific driver was the best and it was cheaper to use it

rather than research on their own to make their own?! And yes, those are

the big companies I'm talking about. One of them claims to be 100%

American made--but in fact gets drivers from Taiwan (this is what I was

told by a rep from Crown)

Hey, I could be totally wrong; but try it for yourself.

Blake Engel (All Church Sound; Chicago, IL)

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It is not surprising that when you adjust items for the SAME frequency

response characteristics that they will (regardless of how many

loudspeakers you do this to) have a tendency to sound the SAME. The

equalizer settings however (would) probably be somewhat if not radically

different for each loudspeaker tested.

The real test of loudspeaker response (whether it's good, bad or

indifferent- measured or subjective listening evaluation) would be an

unequalized, out of the box test. This is usually what set the men apart

from the boys so to speak with loudspeaker design and their frequency

responsiveness.

Barry Birdwell (Birdwell Acoustics; Nashville, TN)

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Barry,

This is true, but to complete an install, don't you set your EQ to

get the best possible sound?! Who cares what the settings are if you

get the best sound, right?

Blake Engel (All Church Sound; Chicago, IL)

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Blake,

A radical EQ setting is always worse than a non-radical EQ setting.

Many reasons! One, the EQ is noisier with non-zero faders. Two, the

EQ filters can ring a bit, adding to coloration. Third, bigger phase

disturbances introduced with radical EQ settings -are- audible, even

if the amplitude response is "flat". Fifth, if a radical dip is necessary

to flatten out a speaker, there are other problems with that driver: it

could be beaming, which will mean very uneven polars. That driver will

probably also be more susceptible to distortion products showing up at

that particular range.

Etc, etc, etc... An EQ is not the solution to a nasty speaker - good

engineering of a speaker and all of its components is!

Bob Puff (New Life Electronics; Rochester, NY)

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Hi, y'all!

There has been an interesting dialog on the list lately about the

thought that "all speakers of the same basic makeup will sound identical

when EQ'd". I wanted to take a moment to pull us back to reality.

I hope you've taken time to read the responses from Ray Rayburn, Russ

O'Toole, Barry Birdwell, and me. To summarize this issue in a word, NO,

they will not sound "identical"! They cannot. No matter how badly you

want to believe that. Some might sound similar up to the first crossover

frequency. But above that, they are worlds apart, for all the reasons

that the above participants have stated recently.

Remember that every manufacturer approaches the design of their MF and

HF horns a bit differently. Stand fifty feet back from a Community RS220,

an EAW KF300, a Renkus-Heinz SR5/9, and an EV DeltaMax - go ahead and

EQ them until they're flat as a pancake. Then, if nothing else, just

listen to their vocal projection. Walk across their pattern and listen

carefully. I promise you in a double blind test that even the untrained

ears of your congregation will hear the difference.

Sorry. It's God's laws of physics, not mine.

Curt Taipale (Taipale Media Systems, Inc.)

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Greetings,

In regards to the thought that all of the top 6 speaker companies use

the same HF drivers - I don't think that I would have said anything like

that without a tranquilizer dart to the head. In my capacity as the TEF

Product Manager I have had the opportunity to visit most of the

significant and some not so significant loudspeaker companies in the world.

You would be quite surprised who makes in-house and who buys from who out

there. There are some of the better known speaker companies that buy

drivers from an OEM supplier who manufacturers these driver components

to the specifications of the speaker companies who assemble them into

their speaker systems. Others like Community, JBL, EV and Renkus Heinz

make most all of their driver components in house. Many of the others buy

from the big boys, OEM sources, and make some of their drivers. Even when

these speaker companies buy drivers from other speaker companies they

often hop them up with ferrofluid or make small alterations. So in short,

the answer to your question is no.

In regards to the loudspeaker listening tests. Having measured literally

hundreds of different loudspeakers under controlled circumstances and in

the field I don't believe that any two sound exactly the same. Sometimes

it is difficult to find two of the same model that sound the same. Here

are a couple of points to keep in mind when you are addressing the sound

of a loudspeaker.

First there are three fundamental aspects which come into play in any

sound.

These are Energy, Frequency and Time. Added to these fundamental sound

elements are the issues of control, device interaction, directivity and

power bandwidth. All of this sums up to a seriously complex and intricate

mix that when applied to loudspeakers is so complex that, like in medicine,

frequently designers specialize in a particular type of speaker component

or system. For instance you could take the exact same HF driver and mount

it on several different horns and you would be hard pressed to believe it

is the same driver. That's only horns. Try the balancing act of how the

crossover should be set. Some of the things to be considered are power

handling of the components, useable frequency range of the drivers,

directivity at crossover, signal synchronization, slope of the filter,

topology of the filter, CD horn HF correction and did I mention price

both manufacturing cost and selling. I assure you there are no two

loudspeakers designs truly alike.

Second if you apply an equalizer to the speakers you only have control

over some of the frequency/magnitude points of the loudspeaker response.

You have no control over the time issues or the directivity properties

of the speaker. An EQ can only change the frequency vs. magnitude response

of the speaker. One-third octave units have desperate limitations as to

how well they can correct the loudspeaker frequency response as the

anomalies in a loudspeaker can be significantly narrower than 1/3 octave.

Even a really good totally parametric EQ has a rough time correcting

the frequency response of the speaker. Frequency response is only about

one half of the picture. There is the time response, polar response and

distortion. Distortion? It comes as a surprise to most people but the

majority of the "good" loudspeakers have typical THD numbers around 2%

or so somewhere in their response curve. Again, the issues of what can

be corrected with an EQ become the limitation of what can be done to tame

a loudspeaker.

Third, even if careful and appropriate EQ was applied to two different

loudspeakers the possibility of matching them within a dB of each other

is slim. In double blind testing (it) is possible to hear differences as

small as 3 dB. We have not even begun to discuss the listening environment

and the effect of directivity on the reverberant field. So you see that

the best that one could ever hope for is "close" and it usually boils

down to which one sounds better than another.

..... I hope I have not been too long-winded on this subject but I

could go on for hours and only scratch the surface. Again I hope that

I have answered your questions and look forward to hearing from you

in the future.

Blair McNair (Crown International; Elkhart, IN)

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OK, So I'm wrong--I've been wrong before, and I _know_ I'll be wrong

again. That's part of the purpose of this list, right? To help dispel

the myths that are out there....

I got my information from (2) different people, both of which I highly

respect. I haven't had the time to do this myself, but they BOTH

assured me of the results. Ah, can't trust anyone but your own ears!

Thanks for your criticism and support!

Blake Engel (All Church Sound; Chicago, IL)

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