How should 1.2TLs appear on spectrum Analyzer

tugboat

I recently came into possession of an EQ with a pink noise generator, microphone and LED display (Audiosource EQ-ONE). For the heck of it I hooked it up and thought I'd check out the results of my 1.2TLs in their current environment. What I saw as a bit disturbing, but has to be wrong. The levels from 1KHz down were pretty even, but from there up it made a drop in level all the way to the 16KHz level. The 8KHz and 16KHz registered 8 to 12 dB lower. I thought it was because of the interconnect, so I removed it. Same results. If I move the control up until they are near even levels on the display, it is way to harsh and very unnatural sounding.

So is it the unit, microphone, speakers or a combination? Just wondering if these speakers are doing something to interfere with the mic picking up the frequencies properly.

For clarification, the speakers sound just fine and all drivers are working. They are also within specs based on the testing procedures found here.

[Deleted User]

Here's the reply from Matt Polk:
"Ken –

In general, never trust results from an analyzer, like the Audiosource, that shows only full-octave bands. You need at least 1/3rd octave resolution. The other big problem is that this type of measurement doesn’t distinguish between what the speaker is doing and what the room is doing. Since lower frequencies bounce around the room much longer than high frequencies this type of measurement will always show much more mid and low frequency energy than high frequency energy. Making meaningful measurements in a normal room can be done but not with that piece of equipment.



Then there’s the problem of SDA. It’s very difficult to get measurements on the SDA’s that have any relationship to how the speakers should sound. This was always a problem with reviewers who would use their standard measurement techniques and get strange results which sometimes influenced their reviews. The 1.2TL’s are especially hard to measure due to the number of different drivers and tweeters all covering different frequency ranges. Then there’s the SDA stuff which is still doing something even when the interconnect isn’t connected. We used a dummy head with mics in the ears to make measurements using a B&K FFT system but only as a guide. The final voicing was done by ear and this is what counts.



What makes the SDA’s unique is that they work the way our ears work. Microphones don’t. If you tried to design an SDA speaker based on microphone measurements it would sound horrible. He found this out when he tried equalizing the speakers according to what the Equalizer was telling him. Experimentation is always a good way to learn something!

-msp

Cheers, Ken

nooshinjohn

It is possible your speakers are in need of a crossover upgrade, and possibly tweeters as well

tugboat

The X-Overs have been upgraded with Sonicaps, Mils, Polyswitches removed, Bypass caps removed, etc. Tweeters are still 3000s, but all are functioning.

pkquat

If I recall that eq is 20+ years old. The mic could be off some, or the electronics have aged. I would check it out on other speakers. You may find similar results. I found that the pink noise and mics from back then were not all that accurate, even with single frequency generation. An 8-12 db roll off will be very audible.

tugboat

pkquat wrote: »

If I recall that eq is 20+ years old. The mic could be off some, or the electronics have aged. I would check it out on other speakers. You may find similar results. I found that the pink noise and mics from back then were not all that accurate, even with single frequency generation. An 8-12 db roll off will be very audible.

I guess I'll have to go pull some speakers out of storage to test. With these 1.2TLs I haven't had the need for any others.

I sent an email to Audiosource about changing out all the electrolytic caps. I see no way of calibrating anything inside, so I don't think I can hurt anything by using the same values and specs (low leakage, etc.). All other component see to be ceramic, possibly film and lots of ICs.

I think I can give the mic to a friend that works in a recording studio. He should be able to test the mic.

Thanks for the input.

F1nut

Curious....since they sound good to your ears, why bother with the EQ thing?

tugboat

F1nut wrote: »

Curious....since they sound good to your ears, why bother with the EQ thing?

No real intention on using the EQ. Just wanted to see the reading and how close they were to being flat. Thought if the mic and analyzer worked, I might be able to use the function to address any issues with room treatments, etc.

madmax

They should not be flat. Last time I was in posession of some good measuring equipment I noticed the lower octaves were strong, dropped off in the lower mid-bass then came back up somewhat below 1Khz. I seem to remember someone at Polk saying they were voiced in that way. I remember setting an EQ so they ended up flat and they lost all their magic.

heiney9

Using 20+ year old inexpensive, mass produced consumer grade audio components and you wonder why the results read poorly. Those were more gimmick than an actual tool.

In room results with variable frequency source material (ie; songs vs. test tones) won't get you close to what ever it is you think it should "measure" like.

Trust your ears, far more sophisticated and reliable than cheap, decades old audio gimmick type gear.

H9

RandyCroissant

Spot on, your ears are the best tool you will ever own and they are free.

tonyb

F1nut wrote: »

Curious....since they sound good to your ears, why bother with the EQ thing?

Was gonna ask that same question, since they sound good to him.

Waste of time if you ask me. We all hear differently and if you are lucky enough to find the sound that pleases you, why screw with it.

Ruler flat doesn't necessarily mean good sound either, so I don't know why some put the energy into achieving that instead of just listening.

Unless watching the lights bounce around gives you a woody, I'd sell it and put the money towards other things.

tugboat

I specifically noted in my OP that I hooked it up for the "heck" of it. I wanted to see what it would look like on the analyzer. I also stated that I came into possession of the EQ. I never said I spent any money on it or was intending on doing so. I'm sure many here has even done something just to learn the results.

I guess a simple question isn't always a simple question. Especially when more is read into that question.

Thanks for the input.

mikeyb128

If you want real results, down load room equalization wizard and spend 80 bucks on a mic. But then again it doesn't sound broken so why try to fix something.

I have a friend who obsesses over home theater and is constantly doing rew sweeps with his room. He complains of a dip between where the mains cross over with his sub. I asked him if it shoulds good? He said "well yeah, but I think I'm losing some mid bass, but is sounds great". Lol

leftwinger57

Guys, could you help me out here. Little on the science, but of course I heard of pink noise and white noise tests. I have only 1 occasion were I heard what I thought was a white noise test to do sweeps in a concert hall Winterland Arena to be specific and what became the intro if you will to what was the start of the Starship's show. It wasn't feedback and nothing else was on so that's why I believe it was a white noise test as opposed to pink noise were I think you need something produced to be measured. I might very well be wrong. Whether it was a tape loop or not I don't know but don't think so and again was used as the into to the opening song then went away. This was the 1st and only time I ever heard this at a concert. Anyone out there ever hear of this before, and is white noise used to set parameters of said concert hall ?

K_M

tonyb wrote: »

F1nut wrote: »

Curious....since they sound good to your ears, why bother with the EQ thing?

Was gonna ask that same question, since they sound good to him.

Waste of time if you ask me. We all hear differently and if you are lucky enough to find the sound that pleases you, why screw with it.

Ruler flat doesn't necessarily mean good sound either, so I don't know why some put the energy into achieving that instead of just listening.

Unless watching the lights bounce around gives you a woody, I'd sell it and put the money towards other things.

To strive for something that is perhaps even a bit more pleasing or accurate.

OR, as the OP said, to simply try out the device he stumbled onto..........
And to ask a simple question about it.....lol

heiney9

You got your answer. It's an inexpensive piece that won't accurately give you an in room reading.

Simple answer to a simple question.

There is nothing you can modify in the unit to make it better analyze. It is what it is, an inexpensive piece with pretty lights.

H9

tugboat

Glad to see this place hasn't changed. I guess it is insanity to expect different results.

No, I didn't get my answer. Again, some are not reading correctly. I asked how they should look on an analyzer. I didn't ask about the quality or value of the unit I was trying. I wanted to know if the design of the SDAs created an issue with how the results would look so I could compare them to what I was seeing.

That is a simple question and some gave answers to a question modified in their head.

Nightfall

tugboat wrote: »

I asked how they should look on an analyzer.

Depends on the room.

heiney9

Depends 100% on the room, that's why speakers are measured and designed in an anechoic chamber. I'm pretty sure a spectrum analyzer isn't a good measurement tool. If you look at professional reviews that do actual in room measurements, they use multiple pieces of sophisticated gear and very specific conditions. Change the conditions, changes the outcome.

Here's a review of the original SRS's. Expect this is what they sound like when set-up according to the specific criteria of that review scenario.

http://www.polksda.com/srsreview.shtml

H9

FTGV

Nothing SDA specific.The room ,mic quality ,mic position (on or off tweeter axis horizontal and vertically)and measuring distance will all have a large influence on the result.For really accurate frequency response measurements you need a good calibrated microphone and a computer based analyzer that can gate out the floor,wall and ceiling reflections.

tonyb

How do you think they should look ? Most here don't use them so that may be why you aren't getting the answers you want.

Your question is like asking how should x receiver sound. There is no right answer because it all sounds different to different people. How a speaker looks on an analyzer and what that means will be very different for people.

So I ask you, how do you think the 1.2's should look ? Do you have a baseline to reference how they should look to see if your off ? Is there even such a thing aside from the manufacturers data taken in special room to measure these things ? If so, who's baseline and how was it obtained ? Do you think another's baseline would offer the same results in your room on your system ?

You measure frequency response to get rid of, or accentuate certain "in-room" responses....and to what pleases your ears. How the 1.2's look, or measure in another person's room and preferences has no bearing on yours. Thus makes those spectrum analyzers a nice light show, but not much use for anything else plus they add noise to the signal which most try and avoid....hence why most don't use them and why your not getting any answers.

Not trying to be a putz here, but it's not the forum's fault your asking questions about a piece of gear hardly anyone uses anymore let alone with 1.2's.

K_M

Obviously no one has measured them on the forum.
You may want to try a more technical type forum, such as part express's forum.
There are many people there that have measured speakers and it could provide much more technical type of assistance, in measuring speakers and so on.

Since they were produced so long ago, it appears very hard to find any actual test results for frequency response anywhere online.

Remember only one of the tweeters on this speaker produces the highest tones, so your mic needs to be aligned with that particular one.

Your mic may not be accurate. (most likely)
I would imagine it should be relatively flat up to about 14-15 khz. Not "Flat" per se, but not drooping off as much as the OP describes.

Good luck, sounds fun!

K_M

We would be happy to do the test on our pair, but are not in florida now, so the mic would have to be quite a distance!

We have that Room Eq Wizard program, and have done it with other ones we own, ( a tedious and boring process, but I have to help..)

When we get back from the islands, we will be home in florida a few days, I can see if we can, but can not promise, we are just going to check on house for like 2 days.

tugboat

Nightfall wrote: »

tugboat wrote: »

I asked how they should look on an analyzer.

Depends on the room.

True, I guess what I'm really trying to get at is that since the they work to cancel certain crosstalk, would that be something the mic of the analyzer would be able to detect and would that alter what the display would show.

tugboat

heiney9 wrote: »

Depends 100% on the room, that's why speakers are measured and designed in an anechoic chamber. I'm pretty sure a spectrum analyzer isn't a good measurement tool. If you look at professional reviews that do actual in room measurements, they use multiple pieces of sophisticated gear and very specific conditions. Change the conditions, changes the outcome.

Here's a review of the original SRS's. Expect this is what they sound like when set-up according to the specific criteria of that review scenario.

http://www.polksda.com/srsreview.shtml

H9

Thank you. This is helpful.

tugboat

tonyb wrote: »

How do you think they should look ? Most here don't use them so that may be why you aren't getting the answers you want.

Your question is like asking how should x receiver sound. There is no right answer because it all sounds different to different people. How a speaker looks on an analyzer and what that means will be very different for people.

So I ask you, how do you think the 1.2's should look ? Do you have a baseline to reference how they should look to see if your off ? Is there even such a thing aside from the manufacturers data taken in special room to measure these things ? If so, who's baseline and how was it obtained ? Do you think another's baseline would offer the same results in your room on your system ?

You measure frequency response to get rid of, or accentuate certain "in-room" responses....and to what pleases your ears. How the 1.2's look, or measure in another person's room and preferences has no bearing on yours. Thus makes those spectrum analyzers a nice light show, but not much use for anything else plus they add noise to the signal which most try and avoid....hence why most don't use them and why your not getting any answers.

Not trying to be a putz here, but it's not the forum's fault your asking questions about a piece of gear hardly anyone uses anymore let alone with 1.2's.

Since SDA works by canceling crosstalk, I was wondering if this would also affect the results of measuring them. If they can make a sound disappear to my ear, could it also do it to the mic/analyzer.

tugboat

K_M wrote: »

Obviously no one has measured them on the forum.
You may want to try a more technical type forum, such as part express's forum.
There are many people there that have measured speakers and it could provide much more technical type of assistance, in measuring speakers and so on.

Since they were produced so long ago, it appears very hard to find any actual test results for frequency response anywhere online.

Remember only one of the tweeters on this speaker produces the highest tones, so your mic needs to be aligned with that particular one.

Your mic may not be accurate. (most likely)
I would imagine it should be relatively flat up to about 14-15 khz. Not "Flat" per se, but not drooping off as much as the OP describes.

Good luck, sounds fun!

A friend has taken the mic to his studio and he is testing it. It's supposed to be flat 10 - 20,000. Of course it is on the older side, so it might be off (most likely). He will find out. If it's off, it's in the trash.

heiney9

tugboat wrote: »

Nightfall wrote: »

tugboat wrote: »

I asked how they should look on an analyzer.

Depends on the room.

True, I guess what I'm really trying to get at is that since the they work to cancel certain crosstalk, would that be something the mic of the analyzer would be able to detect and would that alter what the display would show.

No. It can't detect the amount of ambient reverb in a recording either.

H9

K_M

tugboat wrote: »

tonyb wrote: »

How do you think they should look ? Most here don't use them so that may be why you aren't getting the answers you want.

Your question is like asking how should x receiver sound. There is no right answer because it all sounds different to different people. How a speaker looks on an analyzer and what that means will be very different for people.

So I ask you, how do you think the 1.2's should look ? Do you have a baseline to reference how they should look to see if your off ? Is there even such a thing aside from the manufacturers data taken in special room to measure these things ? If so, who's baseline and how was it obtained ? Do you think another's baseline would offer the same results in your room on your system ?

You measure frequency response to get rid of, or accentuate certain "in-room" responses....and to what pleases your ears. How the 1.2's look, or measure in another person's room and preferences has no bearing on yours. Thus makes those spectrum analyzers a nice light show, but not much use for anything else plus they add noise to the signal which most try and avoid....hence why most don't use them and why your not getting any answers.

Not trying to be a putz here, but it's not the forum's fault your asking questions about a piece of gear hardly anyone uses anymore let alone with 1.2's.

Since SDA works by canceling crosstalk, I was wondering if this would also affect the results of measuring them. If they can make a sound disappear to my ear, could it also do it to the mic/analyzer.

Where and how was the mic located, when you measured?

Was it up really close, or at one meter, or way back in the room? and was it at the height of the tweeter that plays full range?

K_M

.

tugboat

K_M wrote: »

tugboat wrote: »

tonyb wrote: »

How do you think they should look ? Most here don't use them so that may be why you aren't getting the answers you want.

Your question is like asking how should x receiver sound. There is no right answer because it all sounds different to different people. How a speaker looks on an analyzer and what that means will be very different for people.

So I ask you, how do you think the 1.2's should look ? Do you have a baseline to reference how they should look to see if your off ? Is there even such a thing aside from the manufacturers data taken in special room to measure these things ? If so, who's baseline and how was it obtained ? Do you think another's baseline would offer the same results in your room on your system ?

You measure frequency response to get rid of, or accentuate certain "in-room" responses....and to what pleases your ears. How the 1.2's look, or measure in another person's room and preferences has no bearing on yours. Thus makes those spectrum analyzers a nice light show, but not much use for anything else plus they add noise to the signal which most try and avoid....hence why most don't use them and why your not getting any answers.

Not trying to be a putz here, but it's not the forum's fault your asking questions about a piece of gear hardly anyone uses anymore let alone with 1.2's.

Since SDA works by canceling crosstalk, I was wondering if this would also affect the results of measuring them. If they can make a sound disappear to my ear, could it also do it to the mic/analyzer.

Where and how was the mic located, when you measured?

Was it up really close, or at one meter, or way back in the room? and was it at the height of the tweeter that plays full range?

The mic was in the position my head occupies when listening. It's about 6' away and 4' high. It was slightly angled upwards towards the drivers.