Celestion F12-X200

[fuzzydude]

The low end looks wrong and inconsistent, high end trough that should be there isn’t, etc.

Are you aware that I am modifying the frequency response with a 31 band equalizer? Which speaker chart are you talking about? I appreciate your help, but I feel you're jumping to conclusions that make me not want to hear your opinions. In other words, I can sense when someone is just trying be a know-it-all versus trying to be helpful.

What are you going to do with the 3d printed HF driver horn, just put it in front of the F12-X200?

It would be part of a learning experiment based on mathematically generated curves for the horn. I'm not making any guarantees. Surely you've experimented before?

 

[Dave Merrill]

Your measurements look highly dubious, I’m almost certain they’re useless... What are these graphs, RTA?

A horn doesn’t work without its matched driver…

If you shoot for RTA flat, the sound system will not be flat. LF from speakers is less directional than HF. So if you have a flat anechoic/direct-sound sound system, it’s putting out a lot more LF energy into the room than HF. And the RTA with its time smear will look like a LF shelf boost with a HF roll off, with its exact shape varying depending on the sound system and the room.

“Flat sounds bright” is an oxymoron. RTA flat =/= flat. If a flat speaker sounds bright, then what you’re putting into it is bright.

If you have a system that's "RTA flat" -- to be specific, flat with no "house curve" -- do well recorded records sound "normal" to you with no EQ?

This degenerates into a hall of mirrors real quick. Those of us who aren't mastering engineers working in multi-million-dollar tuned listening environments really have no idea of the "real" frequency balance of the music we listen to, or what it "should" sound like, given the mixer's best guess of what their audience likes, and how their sound systems will reproduce the mix they end up with.

 

[yeky83]

Are you aware that I am modifying the frequency response with a 31 band equalizer?

Yes.

Which speaker chart are you talking about?

Charts you posted which I quoted.

I appreciate your help, but I feel you're jumping to conclusions that make me not want to hear your opinions. In other words, I can sense when someone is just trying be a know-it-all versus trying to be helpful.

Trying to be helpful, which is why I’ve been asking about your measurement setup so I don’t jump to conclusions. So care to describe your measurement setup?

If you have a system that's "RTA flat" -- to be specific, flat with no "house curve" -- do well recorded records sound "normal" to you with no EQ?

Seems my post is being misunderstood, I agree an RTA flat sound system is not pleasant, it’d be too bright. RTA is not an ideal measurement, and RTA flat is not a flat sound system. Here’s an article on the topic at hand, hope it helps: https://www.prosoundweb.com/whats-the-measurement-understanding-and-properly-using-rta-fft/

 

[fuzzydude]

Trying to be helpful, which is why I’ve been asking about your measurement setup so I don’t jump to conclusions. So care to describe your measurement setup?

Okay, I don't mind sharing my measurement setup. But first, just to make sure we're not misunderstanding, you opened by writing that the "low end looks wrong and inconsistent." I was trying to EQ a flat response across the frequency range for my FRFR cabinet which was not as flat before, similar to how FRFR amps use DSP to achieve the same. How are you certain that it doesn't look right?

 

[yeky83]

Okay, I don't mind sharing my measurement setup. But first, just to make sure we're not misunderstanding, you opened by writing that the "low end looks wrong and inconsistent." I was trying to EQ a flat response across the frequency range for my FRFR cabinet which was not as flat before, similar to how FRFR amps use DSP to achieve the same. How are you certain that it doesn't look right?

I am not certain, which is why I’m asking. But for one, the low end in your measurement is very inconsistent from one angle to another when they should overlap.

 

[fuzzydude]

I am not certain, which is why I’m asking.

The way I see it, you aren't just asking. You started by saying "I’m almost certain they’re useless." Which is the equivalent of walking into a room, telling everyone they're wrong, then asking them what they are talking about.

But for one, the low end in your measurement is very inconsistent from one angle to another when they should overlap.

My test was from 5 feet away with each cabinet on a pole 5 feet from the ground. REW and umik-1. It is in my sound room and though it isn't a perfect anechoic chamber, it is where I play, so the testing and the results aren't useless to me. The cabinet material (XPS) may serve as a DML (distributed mode loudspeaker) which is causing the odd chart across the angles. I would've explained that in a more friendly way earlier if you hadn't just walked in telling everyone they're wrong.

 

[yeky83]

My test was from 5 feet away with each cabinet on a pole 5 feet from the ground. REW and umik-1. It is in my sound room and though it isn't a perfect anechoic chamber, it is where I play, so the testing and the results aren't useless to me.

That's not a useful measurement to determine the flatness of speakers or even the flatness of what you're hearing in the room. Here's a small guide on how to start making useful speaker measurements: https://www.minidsp.com/applications/acoustic-measurements/loudspeaker-measurements

The cabinet material (XPS) may serve as a DML (distributed mode loudspeaker) which is causing the odd chart across the angles. I would've explained that in a more friendly way earlier if you hadn't just walked in telling everyone they're wrong.

That's not quite it, your CLR and cab measurements both have low end inconsistencies.

If you look at the guide linked above, it should point you in the right direction. I do hope this helps, cheers.

 

[fuzzydude]

That's not a useful measurement to determine the flatness of speakers or even the flatness of what you're hearing in the room. Here's a small guide on how to start making useful speaker measurements: https://www.minidsp.com/applications/acoustic-measurements/loudspeaker-measurements

It seems to me that you're overthinking this. Mostly I'm interested in the flatness of the sound from where I sit relative to where my cabinets sit. It's not a test to describe to the world what this speaker produces in a perfect testing environment. I'm not correcting the CLR at all, so it serves as a good baseline of "flat" and shows me where I should want my curve to be since that is easier than creating an environment I think is flat. Conveniently, the results of the CLR test are flat in the way that I would expect. The CLR results confirm to me that that is the "flat" I'm after. So, I'm able to duplicate that flatness of a well-known flat FRFR speaker designed by a competent speaker engineer with my own relatively cheap speaker and EQ. Here is the official CLR chart. Does this one seem wrong to you as well? I'm sure Jay Mitchell would love to know.

That's not quite it, your CLR and cab measurements both have low end inconsistencies.

If you look at the guide linked above, it should point you in the right direction. I do hope this helps, cheers.

Thanks for your effort, but your criticisms are vague. Maybe explaining your concerns in detail would have been more useful than just voicing disapproval.

 

[yeky83]

It seems to me that you're overthinking this. Mostly I'm interested in the flatness of the sound from where I sit relative to where my cabinets sit. It's not a test to describe to the world what this speaker produces in a perfect testing environment.

Your method doesn't give any info about "the flatness of the sound from where I sit relative to where my cabinets sit."

I'm not correcting the CLR at all, so it serves as a good baseline of "flat" and shows me where I should want my curve to be since that is easier than creating an environment I think is flat. Conveniently, the results of the CLR test are flat in the way that I would expect. The CLR results confirm to me that that is the "flat" I'm after. So, I'm able to duplicate that flatness of a well-known flat FRFR speaker designed by a competent speaker engineer with my own relatively cheap speaker and EQ. Here is the official CLR chart. Does this one seem wrong to you as well? I'm sure Jay Mitchell would love to know.
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The above graph you posted is from "a test to describe to the world what this speaker produces in a perfect testing environment." The measurements in your room shouldn't look anything like that.

Here is an example of how a flat speaker (like the CLR) in a room should measure:

This is what a measurement that shows "the flatness of the sound from where I sit relative to where my cabinets sit" should look like. The low-end response is dominated by room modes and SBIR and should have large peaks and valleys. Your graphs have none of this and aren't useful. If you want to pursue this topic, you should learn the proper way to use REW and make measurements.

Here's a short guide on speaker-in-room measurements: https://audioxpress.com/article/you-can-diy-an-introduction-to-measuring-rooms

 

[fuzzydude]

Your method doesn't give any info about "the flatness of the sound from where I sit relative to where my cabinets sit."

So the microphone is lying? I appreciate that you have a counterpoint, but I would love it if you just made it. This is exhausting.

The above graph you posted is from "a test to describe to the world what this speaker produces in a perfect testing environment." The measurements in your room shouldn't look anything like that.

And yet when I tested the CLR, the results were very similar to the perfect testing environment. What does that tell you?

Here is an example of how a flat speaker (like the CLR) in a room should measure:

So you are saying the official CLR chart is wrong? I'm starting to think I should stop this back and forth with you now.

This is what a measurement that shows "the flatness of the sound from where I sit relative to where my cabinets sit" should look like. The low-end response is dominated by room modes and SBIR and should have large peaks and valleys. Your graphs have none of this and aren't useful. If you want to pursue this topic, you should learn the proper way to use REW and make measurements.

Here's a short guide on speaker-in-room measurements: https://audioxpress.com/article/you-can-diy-an-introduction-to-measuring-rooms

Well at least now I have a guess as to what you're trying to say. Yes, I would also get similar results if I applied no smoothing. Everyone applies smoothing, including the official chart for the Atomic CLR. I used ERB smoothing.

ERB smoothing uses a variable smoothing bandwidth that corresponds to the ear's Equivalent Rectangular Bandwidth, which is (107.77f + 24.673) Hz, where f is in kHz. At low frequencies this gives heavy smoothing, about 1 octave at 50Hz, 1/2 octave at 100 Hz, 1/3 octave at 200 Hz then levelling out to approximately 1/6 octave above 1 kHz.

I understand that you don't find value in smoothing. I and most others do. Can we move on?

 

[yeky83]

So the microphone is lying? I appreciate that you have a counterpoint, but I would love it if you just made it. This is exhausting.

The microphone isn't lying, your measurement method is not useful. I've made this point many times, dunno how to make it clearer to you.

And yet when I tested the CLR, the results were very similar to the perfect testing environment. What does that tell you?

I've already told you what it tells me. It ought to also tell you something, that something's very wrong when you're getting "results" that are very similar to a perfect testing environment in your very less than perfect testing environment.

So you are saying the official CLR chart is wrong?

No, haven't said any such thing.

Well at least now I have a guess as to what you're trying to say. Yes, I would also get similar results if I applied no smoothing. Everyone applies smoothing, including the official chart for the Atomic CLR. I used ERB smoothing.

ERB smoothing uses a variable smoothing bandwidth that corresponds to the ear's Equivalent Rectangular Bandwidth, which is (107.77f + 24.673) Hz, where f is in kHz. At low frequencies this gives heavy smoothing, about 1 octave at 50Hz, 1/2 octave at 100 Hz, 1/3 octave at 200 Hz then levelling out to approximately 1/6 octave above 1 kHz.

I understand that you don't find value in smoothing. I and most others do. Can we move on?

ERB is just one very simplified approximation of how we hear, and by itself gives very little usable info. REW recommends variable smoothing for applying EQs or psychoacoustic smoothing to better approximate perceived response. I'm guessing the CLR's response has 1/6 octave smoothing applied to it. Try those out instead of ERB. Seems we might've found the culprit in over-smoothing, but there may also be other factors.

 

[fuzzydude]

The microphone isn't lying, your measurement method is not useful. I've made this point many times, dunno how to make it clearer to you.

I've already told you what it tells me. It ought to also tell you something, that something's very wrong when you're getting "results" that are very similar to a perfect testing environment in your very less than perfect testing environment.

No, haven't said any such thing.

ERB is just one very simplified approximation of how we hear, and by itself gives very little usable info. REW recommends variable smoothing for applying EQs or psychoacoustic smoothing to better approximate perceived response. I'm guessing the CLR's response has 1/6 octave smoothing applied to it. Try those out instead of ERB. Seems we might've found the culprit in over-smoothing, but there may also be other factors.

Okay. There isn't much difference between ERB and variable smoothing on the chart. I've seen it. Thanks for your advice. Moving on.

 

[marsonic]

So uh…should I chime in that I kind of think the whole discussion is moot.

These things aren’t hi-fi speakers or monitors. Trying to make them neutral seems like a fool’s errand. IDK…maybe I’m just wrong about that.

FOH should probably be as hi-fi as possible, and it’s down to the FOH engineer to make you sound good. But your stage sound just needs to be inspiring.

Idk. I guess I just don’t get the obsession in this context. In others…I’m a huge fan both of correction following good measurements (REW is so hard to get accurate results with that I don’t find it valuable) and just flat out buying speakers based on spinorama data. So it’s not like I don’t trust our value measurements. I just don’t really see the point for a guitar cab when you can just save a nice sounding EQ with each IR and it’s going to sound different in every room anyway.

 

[yeky83]

Okay. There isn't much difference between ERB and variable smoothing on the chart. I've seen it. Thanks for your advice. Moving on.

There's... a big difference.

These things aren’t hi-fi speakers or monitors. Trying to make them neutral seems like a fool’s errand.

Agreed.

 

[JTI]

Trying to make them neutral seems like a fool’s errand. IDK…maybe I’m just wrong about that.

100%. In the end; you are going to feed it Dollar Store IRs that someone else shot so diminishing returns is something of an understatement.

 

[fuzzydude]

There's... a big difference.

Okay. Here's what you're asking for yek83. One var smoothing, the other ERB smoothing.


Now ERB takes into account the difference in the ear's ability to discern bandwidth differences, it makes sense to use the ERB smoothing to flatten a curve instead of the var smoothing. Why waste your EQ points in an area that the ear can't hear gaps as well as at the top end?

Agreed.

These are not crappy speakers. But, I would argue that everyone, even with crappy speakers should try to flatten their frequency response to best take advantage of what the speaker is capable of. This is especially important with FRFR speakers. I'm sure everyone has heard even tiny crappy speakers with a custom EQ sound better.

Anybody can correct their speaker, you don't need to tweak your nipples over room reflections and other things unless you really want to.

Here's a good video for correcting your speakers. All it takes is a $100 microphone and an equalizer (preferably analog).

 

[fuzzydude]

So uh…should I chime in that I kind of think the whole discussion is moot.

These things aren’t hi-fi speakers or monitors. Trying to make them neutral seems like a fool’s errand. IDK…maybe I’m just wrong about that.

FOH should probably be as hi-fi as possible, and it’s down to the FOH engineer to make you sound good. But your stage sound just needs to be inspiring.

Idk. I guess I just don’t get the obsession in this context. In others…I’m a huge fan both of correction following good measurements (REW is so hard to get accurate results with that I don’t find it valuable) and just flat out buying speakers based on spinorama data. So it’s not like I don’t trust our value measurements. I just don’t really see the point for a guitar cab when you can just save a nice sounding EQ with each IR and it’s going to sound different in every room anyway.

You bring up a good point. People have different tolerances for what they will accept.

I'm the kind of person who is a bang-for-buck kind of guy. I care about stuff that makes the most difference and ignore the petty details that distract from the big picture. And I'm convinced that EQ correction (to make it flat) on a cabinet makes a big enough difference that you and everyone would agree with me if you could hear the difference. So much so, that after you hear the difference, you'll wonder why everyone doesn't correct their cabinet if they need FRFR. I'm the guy who ignores tonewoods and pushes amp modeling so you know I don't subscribe to those hard-to-hear details that some people can't live without. Yet the difference between a corrected speaker is so significant, cheap, and easy that I'm going to try to get everyone I know to at least hear the difference before deciding.

 

[sprint]

You bring up a good point. People have different tolerances for what they will accept.

I'm the kind of person who is a bang-for-buck kind of guy. I care about stuff that makes the most difference and ignore the petty details that distract from the big picture. And I'm convinced that EQ correction on a cabinet makes a big enough difference that you and everyone would agree with me if you could hear the difference. So much so, that after you hear the difference, you'll wonder why everyone doesn't correct their cabinet if they need FRFR. I'm the guy who ignores tonewoods and pushes amp modeling so you know I don't subscribe to those hard-to-hear details that some people can't live without. Yet the difference between a corrected speaker is so significant, cheap, and easy that I'm going to try to get everyone I know to at least hear the difference before deciding.

+1 - have tried to correct my passive Atomic Reactors (Matrix powered) a few times with limited "newb" success - will try again with info here - don't want to give up on them as I would get nothing in resale and, if successful, would save 8-900$Cdn to build a set of X200s which I keep putting off hoping I can get the Atomics in a reasonably viable place - I think I'm close after the last round of diy flattening / matching to my Yamaha HS8s but maybe I can get them better given the insight here.

 

[marsonic]

Anybody can correct their speaker, you don't need to tweak your nipples over room reflections and other things unless you really want to.

This is backwards. The room makes more of a difference than the speaker.

Assuming that no speaker has significant directivity errors, I'll take $1000 speakers in a $10,000 room over $100,000 speakers in a $1,000 room, even if I'm not paying for them. It's going to sound better.

...at least in a hi-fi or studio context.

You bring up a good point. People have different tolerances for what they will accept.

I'm the kind of person who is a bang-for-buck kind of guy. I care about stuff that makes the most difference and ignore the petty details that distract from the big picture. And I'm convinced that EQ correction on a cabinet makes a big enough difference that you and everyone would agree with me if you could hear the difference. So much so, that after you hear the difference, you'll wonder why everyone doesn't correct their cabinet if they need FRFR. I'm the guy who ignores tonewoods and pushes amp modeling so you know I don't subscribe to those hard-to-hear details that some people can't live without. Yet the difference between a corrected speaker is so significant, cheap, and easy that I'm going to try to get everyone I know to at least hear the difference before deciding.

This isn't about tolerances and what you'll accept, it's about whether or not chasing your tail is actually going to give you an improvement.

The whole sound spectrum changes drastically based on the room and where the speaker is in it, until you're comparing two rooms that are sufficiently big and sufficiently diffuse (which go together, you'll never create a diffuse sound field in a small home studio, for example).

Speakers don't even work the same in small rooms as they do in bigger ones. Below the Schroder frequency for the room (which you can calculate but not really measure using halfway-normal tools), bass actually works by changing the air pressure in the room rather than bouncing around the way highs do. You're essentially sitting inside a giant relatively sealed subwoofer. The pressure changes also aren't constant throughout 3d space, and you're essentially working with trying to smooth out the pressure field at your listening location. You can't do that by getting measurements from a close mic. And you can't do it for the whole room unless the room is huge. And then you're battling inverse square laws for level....so, there's still a serious limit to what can be done.

There are ways to get good measurements for speakers that essentially take the room out of it. The most affordable one I'm aware of is the Kippel Near Field Scanner, which is around $100k. It absolutely can measure speakers insanely accurately including phase distortions between drivers and directivity, and you can use it both to evaluate speakers and generate a very good corrective curve that starts you out flat before your room. And the results can tell you whether it's worth bothering.

As far as correcting it with an analog EQ....just no. There are no analog EQs that are precise enough to linearize a speaker or deal with room effects. Using 31-band (1/3 octave) graphic EQs was a thing 30-40 years ago. Today, no one who knows what they're doing bothers. They're not good enough. Can one make it sound better? Absolutely. They just can't make it accurate.

Now, if you take the science out of it for a minute and just use your ears...listen to it and realize that today it's a little boomy or bright or there's a "thing" at 2.5k that you don't like....EQ it. Make it sound good. If some of those corrections are consistent, awesome. That's less you have to do each time. I like EQ for that....I'm much more likely to tweak an EQ than go searching for a different IR as long as what I'm using is close.

But bringing in measurements for this application....it really seems like you're just going to wind up chasing your tail. I honestly think it's a better solution to use one of your Perform pages for a couple shelves and maybe 1 or 2 parametric bands for in-the-moment corrections and leave making it sound good to everyone else up to the FOH or recording engineer....even if it's you.

ETA:

If your goal is really accurate sound....an F12 isn't the right solution to begin with. It wasn't made for that. If that's your goal, you're better served with good hi-fi or studio speakers in a treated room through room correction or IEMs through correction and possibly HRTF crossfeed.

But, then you lose the amp-in-the-room thing...which mostly comes from the cab interacting with the room. You really can't have both.

 

[fuzzydude]

This is backwards. The room makes more of a difference than the speaker.

I know you have a point, but for the 99.99% of us, no one cares about their room as much as their speaker/cabinet.
Can we agree to disagree and maybe the rest of us can stay who'd rather make their speaker flatter than spend thousands to make their room acoustically neutral?