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[Ivan Beaver]

I have certainly been guilty of spending hours worrying about some little anomaly in the response that probably had no practical impact - and all too often at the expense of issues that did matter.

Agreed

That whole "Can't see the forest for the trees" thing.

We all get hung on the "little things that don't matter in the grand scheme of things" from time to time.

[AllenDeneau]

WOW, thanks all I've certainly learned a few things as well as Ivan pointed out, I have more questions as well..

I understand that, for my current level of service and equipment, that the graphs are of very little use to me as I'm not educated on what they really mean to really analyze. However, the graph along with the Polars, as Brad referred to, can help me take a quick snapshot of it's general characteristics and coverages correct?

By having some understanding of where certain things lie in the frequency spectrum the polars will help me determine if I can get good intelligibility from a single speaker in x sized width of room. Is that correct?

The graph, whether it's been smoothed or not, really helps me determine where my LP and HP filters should be applied in DSP and a general look at the speakers "real" Max SPL, given the graph is somewhat truthful. Is that correct?

Like Brad said, I too have been victim of concerning myself with issues that really aren't an issue in the scheme of things however, I seem to do that in most parts of my life, not just looking at speaker response graphs  For example, I've over thought and over thought my ideas on what to concentrate on as I'm restarting my business after moving over 500 miles from home, I just need to grab and go...

OK, so the $64,000 question is: how to determine if the plots have been smoothed a little, a lot, not at all or if the marketing department had a whack at them? Is it just a call to the relative manufacturer to get such info?

Now, I'd love to actually discuss the graph I posted regarding my OLD SP2G's. I know they aren't the best sounding speaker out there and weren't even in their day but I don't think they're completely horrible either. I've been able to get them fairly smooth with eq but it would be nice to have something a little flatter right from the get go. With that said, until I get re-established and can upgrade, these have to do and I'm ok with that for the most part.

How do I know if the freq response I posted has been smoothed and if it hasn't, is it a really bad response?

Some of you are so much further ahead of me in the game that I'm only hoping to ever acheive even a portion of your understanding. With that being said, I'm asking, if you were speaker shopping, back in the mid '90's when these were new lol, and you looked at the freq response and KNEW it was an unsmoothed graph, what would your thoughts be?
Well, everyone BUT Scott as I already know what he thinks 

What I'm hoping to acheive by asking the last part is, I'd like to see through "your eyes" what the info says, helping me to develope my own "filters" of what info is really saying.. Make sense?

Here it again to save you from going back through the thread.

[Ivan Beaver]

WOW, thanks all I've certainly learned a few things as well as Ivan pointed out, I have more questions as well..

I understand that, for my current level of service and equipment, that the graphs are of very little use to me as I'm not educated on what they really mean to really analyze. However, the graph along with the Polars, as Brad referred to, can help me take a quick snapshot of it's general characteristics and coverages correct?

By having some understanding of where certain things lie in the frequency spectrum the polars will help me determine if I can get good intelligibility from a single speaker in x sized width of room. Is that correct?

The graph, whether it's been smoothed or not, really helps me determine where my LP and HP filters should be applied in DSP and a general look at the speakers "real" Max SPL, given the graph is somewhat truthful. Is that correct?

Like Brad said, I too have been victim of concerning myself with issues that really aren't an issue in the scheme of things however, I seem to do that in most parts of my life, not just looking at speaker response graphs  For example, I've over thought and over thought my ideas on what to concentrate on as I'm restarting my business after moving over 500 miles from home, I just need to grab and go...

OK, so the $64,000 question is: how to determine if the plots have been smoothed a little, a lot, not at all or if the marketing department had a whack at them? Is it just a call to the relative manufacturer to get such info?

Now, I'd love to actually discuss the graph I posted regarding my OLD SP2G's. I know they aren't the best sounding speaker out there and weren't even in their day but I don't think they're completely horrible either. I've been able to get them fairly smooth with eq but it would be nice to have something a little flatter right from the get go. With that said, until I get re-established and can upgrade, these have to do and I'm ok with that for the most part.

How do I know if the freq response I posted has been smoothed and if it hasn't, is it a really bad response?

Some of you are so much further ahead of me in the game that I'm only hoping to ever acheive even a portion of your understanding. With that being said, I'm asking, if you were speaker shopping, back in the mid '90's when these were new lol, and you looked at the freq response and KNEW it was an unsmoothed graph, what would your thoughts be?
Well, everyone BUT Scott as I already know what he thinks 

What I'm hoping to acheive by asking the last part is, I'd like to see through "your eyes" what the info says, helping me to develope my own "filters" of what info is really saying.. Make sense?

Here it again to save you from going back through the thread.

Some answers.  Polar are not easy to read/understand by most people.  If you think a freq response graph is hard-then polars are out of the question.

Polars will give you no information regarding intelligibility.    Just the coverage angle of the loudspeaker at different freq.  Intelligibility is a combination of noise-reflections-phase response-interactions between different loudspeakers-freq response-listening position and so forth.

If the graph looks like the one you show-then it has been smoothed.  If you don't see some radical "spikes" like I presented-then it has been smoothed.  Good luck getting any more details from the manufacturer than they present on the website or on the spec sheet.  But it might be possible.

There is generally no way to tell if the graph presented is "correct" .  I know of cases where the manufacturer simply draws the graph the way they want it to look.

You need to look closely at whether or not any processing has been applied to get the graph.  If it has-then this can RADICALLY affect the max SPL-ESPECIALLY on the low end.  It is pretty common to add a low freq boost to make the response appear to do lower.  It will-until you turn it up.  Whatever was added by boosting-has to be subtracted from the max SPL-At the boosted freq.

The freq response is often only a small indicator of how a loudspeaker sounds.  You can have 2 speakers that measure almost exactly (within 0.25dB) and sound COMPLETELY different.  There is a lot more than just the raw on axis freq response.

Don't expect to learn everything quickly.  Many of us have spent decades in the business on many different sides-and are just beginning to get a small handle on what is going on.  And we get blindsided all the time.

But to put another answer to the "Is it smoothed or not", I can say that in 99.999999999% of the cases it IS smoothed.  I have never seen any manufacturer post any unsmoothed data.  It is simply not in their best interest to do so.  And if they did-then what would you get from it?  And compare it to?

Anybody who "needs" unsmoothed data is going to have their own way to measure it-and surely would not trust any data provided by the manufacturer.

We apply various amounts of smoothing, not in an attempt to "hide anything", but rather to provide some useful information to the viewer.

Regarding trying to use a single graph to try and determine filters-remember that the graph is usually taken in a reflection free environment.  Your usage is probably not that.  You will have boundary loading (which can increase low freq response)-all sorts of reflections, interactions with other loudspeakers and so forth.

Measurements in the existing situation are the ONLY way to do it correctly.  And then you have to do multiple measurements and average.

Don't look for simple answers.  That will result in simple WRONG answers.

[Scott Bolt]

A real Engineer is also going to be looking at polars or balloon data, going to want better information about maximum power (and possibly ask for voltage and current information rather than Watts), will want to see sensitivity versus frequency, will want to see phase data and possibly other technical factors that probably don't matter to or may even discourage the average purchaser.  That has always been the dilemma, providing technical data that is complete and accurate enough for some but not overwhelming or intimidating for others.
 
I think what Tim was referencing was something it took me a while to understand (and that I still am learning) and that is differentiating what is important from what is not.  I have certainly been guilty of spending hours worrying about some little anomaly in the response that probably had no practical impact - and all too often at the expense of issues that did matter.

Sure.  A Nyquist plot would likely be a useful tool to an engineer ..... not so much to others.

I would say that you can't get much of a story from the frequency plot in general.  You aren't going to hear how it sounds by looking at the plot.

To the OP.... from looking at the graph .... I would say it is a little weak on the bottom, has a bit of a hole at ~1.8K which may take away from vocal clarity .... or keep the speaker from sounding harsh   The peak at 500 may make the speaker sound a little "honky".

Since you are using these with subs, normally, I would have suggested a cross-over frequency around 100Hz .... but this speaker appears to have a pretty decent dip right at 100Hz.  There is generally a little notch at the cross-over point anyway, this might make it worse.

I would like to say that there is much more to sound than a frequency plot at 1M on axis.

If you have a digital cross-over like the DRPA, you can setup several presets and A/B them to see what you like, and what you don't.  If not .... well, it is a little harder to change your graphic eq so quickly

I had a friend who works live sound for a living come over one night and ring out my system for me for a steak dinner and a few beers.  That was surely worth every penny

[ProSoundWeb Community]