powered speaker advice

[abzurd]

Huh, maybe sound does matter

 

From the mother of the bride at a wedding we did last night in Cincy.... Notice she even specifically calls out "your sound" and not a general comment that could be misconstrued as just liking the band. That's how I take it anyway.

 

I wanted to add to the bride's comments from last night's event. WOW! It was a wonderful evening...all ages out on the dance floor ALL night! You were very receptive to the bride and groom's requests, your sound was phenomenal and you engaged the crowd the entire evening. Thank you thank you for making their special day even more special!

[Gorquin]

Al can the DXR15's handle the HOT sun in an outdoor environment? How much bottom end will one loose if they used a pair of DXR15's in lieu of say K12's/Ksub or RCF312a/Yorkville UCS1's?

[Al Poulin]

The DXR line has only been out for a short while, so reliability has not yet been determined. The DXRs are fan cooled, but I have noticed that the air coming out is noticeably warm.

 

As for how they would compare to a pair of 312s+ Unity sub : as soon as you have a good sub on the ground handling the lower frequencies, the overall sound is usually better than a single set of speakers on stands. The fact that the sub handles the lows is also much less taxing on the tops, which can now get louder and cleaner.

 

The DXR15s have noticeably more low end presence and extension vs. the 312As or K12s used stand alone, BUT those same tops with a good sub will outperform the DXR15s. A pair of 15s on stands can only move so much air...

 

Al

[OneEng]

The DXR line has only been out for a short while, so reliability has not yet been determined. The DXRs are fan cooled, but I have noticed that the air coming out is noticeably warm. As for how they would compare to a pair of 312s+ Unity sub : as soon as you have a good sub on the ground handling the lower frequencies, the overall sound is usually better than a single set of speakers on stands. The fact that the sub handles the lows is also much less taxing on the tops, which can now get louder and cleaner. The DXR15s have noticeably more low end presence and extension vs. the 312As or K12s used stand alone, BUT those same tops with a good sub will outperform the DXR15s. A pair of 15s on stands can only move so much air... Al

 

I agree; however, for the money, a pair of DXR15's are hard to beat with respect to sound output for the price. They are also pretty easy to setup.

 

They are no match for a good pair of 12" over a good pair of subs, but they are surprisingly punchy for a sub-less FOH setup..... Al did't really give his differentiation justice. A pair of DXR15's will blow away any 12" speaker in this price range when it comes to bottom end

[Al Poulin]

Al did't really give his differentiation justice. A pair of DXR15's will blow away any 12" speaker in this price range when it comes to bottom end

 

Absolutely. I did actually compare the DXR15s in store with the Art 312As and DXR12s, and the extended DEEP low frequency presence of the DXR15s was VERY noticeable.

 

Al

[Vito Corleone]

The week prior I was at a Ben Folds concert with just Ben and his piano at a venue that maybe held 3,000 people. The sound was atrocious and I have the RTA print screen to back it up. He put on a heck of a show, but it was hamstrung by stinky sound and my wife and I were disappointed. Literally 1 vocal mic and what was probably a couple of piano mics. That's it. How could they get it so wrong. That said, I will concede that nobody around me noticed.

 

 

It's not that they didn't notice. It's just that most people aren't educated enough to compare and/or put their finger on the deficiencies. You are, so you know not only know what it could/should sound like, but can explain why. The average person isn't going to complain about poor sound unless there is horrible feedback or they can't hear the vocals or somesuch. And as long as the artist they want to see performs reasonably well and plays the songs they want to hear, they'll enjoy the concert. But a great sound might be the difference between them enjoying the show and them being blown away and leaving thinking it was the best concert ever!

 

Simply because people don't come up and tell you your sound sucks doesn't mean that better sound won't benefit you.

[Vito Corleone]

Regardless, I still disagree and I have been playing out for more than 25 years. I have seen (and still see) amazing bands with {censored} equipment get paid great money and crappy bands with crappy equipment get great money for a variety of reasons.

 

 

No doubt that happens. But that's no reason to dismiss the importance of good sound. Simply because you MIGHT be able to get by with a big weak spot in your band---whether it's a sloppy drummer or a lousy singer or a {censored}ty sound system---why would you if you don't absolutely have to?

 

And while good sound isn't cheap, it's at least something that once you have it, it isn't going to show up drunk or hit on your girlfriend. It will be one of the most reliably consistant good features of your band. So why wouldn't you want to do everything you can to have it?

[abzurd]

It's not that they didn't notice. It's just that most people aren't educated enough to compare and/or put their finger on the deficiencies. You are, so you know not only know what it could/should sound like, but can explain why. The average person isn't going to complain about poor sound unless there is horrible feedback or they can't hear the vocals or somesuch. And as long as the artist they want to see performs reasonably well and plays the songs they want to hear, they'll enjoy the concert. But a great sound might be the difference between them enjoying the show and them being blown away and leaving thinking it was the best concert ever! Simply because people don't come up and tell you your sound sucks doesn't mean that better sound won't benefit you.

 

Sure, I get that. I was just disappointed that something so easily made to sound decent was just ignored. The opener's sound (solo acoustic) was even worse.

 

Anyway, here's an RTA sample. Nothing like uber 250 Hz with no high end. Basically 2 hours of "wool".

 

[jwlussow]

Sure, I get that. I was just disappointed that something so easily made to sound decent was just ignored. The opener's sound (solo acoustic) was even worse. Anyway, here's an RTA sample. Nothing like uber 250 Hz with no high end. Basically 2 hours of "wool".

 

YUCK

[Vito Corleone]

Sure, I get that. I was just disappointed that something so easily made to sound decent was just ignored. The opener's sound (solo acoustic) was even worse. Anyway, here's an RTA sample. Nothing like uber 250 Hz with no high end. Basically 2 hours of "wool".

That's ugly. Makes you wonder who, if anyone, was doing sound at that gig??

[abzurd]

We're not talking small time venue either. Here are pics from the same venue a few weeks later. The sound was better, but not stellar. It was painfully peaky at times in the 1K-2K range with no sibilance.

 

 

 

[agedhorse]

Sure, I get that. I was just disappointed that something so easily made to sound decent was just ignored. The opener's sound (solo acoustic) was even worse. Anyway, here's an RTA sample. Nothing like uber 250 Hz with no high end. Basically 2 hours of "wool".

Is this sample with pink noise? What was the mic and app being used?

[abzurd]

 

Is this sample with pink noise? What was the mic and app being used?

 

 

It's the iphone mic with a Six digital RTA app (yes, I know you don't think the measurement is worth a darn). Trust me, it sounded like this. I forget the setting I was using but I think it was a 10 second average. I took the measurement during what I considered to be "normal" time in the show and not while something unique was occurring. I also took measurements multiple times and they all look similar to this. It's just for illustration purposes.

 

FWIW, I've compared my iphone to a calibrated measurement mic and while under 150 Hz is a bit dicey, it's not all that bad otherwise and has been usable, especially for ringing out monitors.

[agedhorse]

It's the iphone mic with a Six digital RTA app (yes, I know you don't think the measurement is worth a darn). Trust me, it sounded like this. I forget the setting I was using but I think it was a 10 second average. I took the measurement during what I considered to be "normal" time in the show and not while something unique was occurring. I also took measurements multiple times and they all look similar to this. It's just for illustration purposes. FWIW, I've compared my iphone to a calibrated measurement mic and while under 150 Hz is a bit dicey, it's not all that bad otherwise and has been usable, especially for ringing out monitors.

 

 

With music as a source, the display should NOT be flat, all it represents is the energy spectrum OF THE MUSIC NOT THE PA'S RESPONSE averaged over 10 seconds.

 

Withthe I-Phone's internal mic, the low and high frequency areas may be off by as much as 8-10dB, another potential source of major error.

 

Not saying that it didn't sound bad, but the RTA display doesn't prove (or even say) anything.

[abzurd]

 

With music as a source, the display should NOT be flat, all it represents is the energy spectrum OF THE MUSIC NOT THE PA'S RESPONSE averaged over 10 seconds. Withthe I-Phone's internal mic, the low and high frequency areas may be off by as much as 8-10dB, another potential source of major error. Not saying that it didn't sound bad, but the RTA display doesn't prove (or even say) anything.

 

 

Where did I say it should be flat? I know it shouldn't be flat. The all caps wasn't really necessary. Of course it represents the program material, which was the point. It should have more high frequency energy when averaged over time and vocals strong in the mix.

 

Honestly, I wanted to post this right after I went to the concert but didn't because I knew this exact situation would occur. I decided, despite having to endure the criticism, I'd post it anyway.

 

FWIW, I RTA'd the other show where the 1K-2K was painful and the graph showed exactly what I was hearing.

[agedhorse]

Of course it represents the program material, which was the point. It should have more high frequency energy when averaged over time and vocals strong in the mix..

 

 

Maybe, but maybe not. It really depends on the specific program content, how much background noise spectrum contamination was infused into the measurement by the audience and ambient refections, and definately the HF response of the measurement system which from the data I have seen is VERY limited on the I-Phone platform.

 

This is a case IMO where the data may "kind of match" what you thought you were hearing but can not be trusted because it's taken in an uncontrolled (source) and uncalibrated (measurement platform) environment.

 

It's a pet peeve of mine where measurement data is taken out of a controlled context and (especially critical) conclusions are drawn based upon it.

[abzurd]

 

Maybe, but maybe not. It really depends on the specific program content, how much background noise spectrum contamination was infused into the measurement by the audience and ambient refections, and definately the HF response of the measurement system which from the data I have seen is VERY limited on the I-Phone platform. This is a case IMO where the data may "kind of match" what you thought you were hearing but can not be trusted because it's taken in an uncontrolled (source) and uncalibrated (measurement platform) environment. It's a pet peeve of mine where measurement data is taken out of a controlled context and (especially critical) conclusions are drawn based upon it.

 

 

No, not maybe. I was there. It sounded bad, really bad. It sounded like the graph I posted (big 250hz hump that dominated the material... it stunk). Do I need to put my wife on the witness stand to corroborate my testimony that I told her BEFORE taking the measurements, what the measurement was going to say? Do I really need need a disclaimer that this was a casual measurement for illustrative purposes only? I believe I pretty much have done this already. I get that this is a "non-Andy" approved graph. Heck, no measurement was needed for anyone actually paying attention and giving a crap. My wife was immediately disappointed.

[jwlussow]

I do know and have been able to demonstrate consistently that the iPhone and iPad freq response readings are very close to both Spectrafoo and the internal processing from my Driverack 260. Not absolutely identical but certainly as accurate as I'd ever need. I use the dbx RTA mic and the DR 260. I use another dbx RTA for Spectrafoo. I am actually pretty impressed with the perceived accuracy and the visual results are accurate to what I believe I hear. My actual hearing is pretty much shot with so much noise from the tinnitus in my right ear that I had to give up my studio work.

[agedhorse]

All I am saying is that a graphm with music used as the source doesn't mean anything in general.

What you heard means more to me than what the display says because you (ears and brain) are factoring what you hear into the context of the music which the display can not (unless it's looking at the source AND the measurement and displaying the DIFFERENCE). For example, if that was the display for a male vocal and say a B3 (think gospel), it's just about what I would expect, but for a rock band with guitars and a female lead singer maybe not. How loud the bass guitar was mixed could have as big of an impact as how the system was tuned... maybe even more.

I saw some sample testing by Marsh & Assoc (IIRC) of the various I-phone apps using internal mics and there were serious issues at both the low and especially high frequencies. There were also boundery issues depending on the orientation of the mic and surrounding surfaces like your body and hand placement. The differences were so large that I could never rely on one for any kind of evaluation measurement where a decision was necessary. Now if and when the lineearity of internal mics change, or where an external and reasonably calibrated mic was used, the app might be just fine and in fact highly attractive IMo. I am talking about the phone or touch or pad like device as a stand alone system. As soon as I have to start using external hardware, it takes away from the attraction of an integrated device.

Also, IF you have access to a mic calibration system, it's possible to develop and enter correction parameters but this is not something that most folks (including me) have access to as it's expensive, specialized equipment. A real calibrated mic is less expensive.

[agedhorse]

Regarding mic linearity and all of the variables that are not immediately recognizable to average users but are essential to understand when determining the accuracy for a more sophisticated or demanding application, read the following info on measurement mics and the reason why the I-Pod with the internal mic is useless for any kind of accurate measurement:

Aside from the serious HPF, the measurement tolerance at hiogh frequencies of the typical mic element swings from 9dB of possible variation to undefined (at the top 2/3 octave of the measurement scale) How can you make a statement with any kind of surity if the measurement tolerance is so wide or even undefined?

From the Studio Six app notes:

http://www.studiosixdigital.com/iphone_3gs_microphone.html

[abzurd]

Yes, I've cited that very same Studio Six page myself.

 

There's not really much to say. You are set on keeping every conversation around here technical. I've taken a casual approach on this from the start as was merely "shooting the $h!t", not trying to spread inaccuracies. There's something to be said for being accurate, of course, but damn you can be a killjoy. "Uncle" I guess

[agedhorse]

Yes, I've cited that very same Studio Six page myself. There's not really much to say. You are set on keeping every conversation around here technical. I've taken a casual approach on this from the start as was merely "shooting the $h!t", not trying to spread inaccuracies. There's something to be said for being accurate, of course, but damn you can be a killjoy. "Uncle" I guess

There are folks here that are trying to understand this stuff and your comments are misleading and inaccurate. I am not being a killjoy, I am placing your comments in context with what is really happening (IMO). I don't know why you are so sour on being accurate?

Here's a great example of why you need to know exactly what you are measuring with, the frequency response of the mics and processing on the I-Phones is all over the map and if you thought your mic was even reasonably flat but it really looks like the standard I-Phone mic trace (in red on the comparison graph), you would look like a fool trying to defend any measurement made with this device. Rule number one... know that your measurement tool is actually measuring what you think it's measuring and not something based on inaccurate data. I'm talking about problems that are a factor of 10 inaccurate. I'm not messing around with tiny differences.

http://blog.faberacoustical.com/2009/ios/iphone/iphone-microphone-frequency-response-comparison/

I hope this is useful to at least some of you guys who might be exploring an app like this with the intent to tune your system. Know what's a reasonable expectation and what's not.

[jwlussow]

Next time we pink our system I'll pay closer attention to the graphs. I do know with Foo we can compare pre and post signals so we can have two screens, one of the live source material and a second of the processed FOH signal. We try to get them as close as possible to each other. I'll play with the iPhone and iPad too.

 

I was never looking for a scientific proof of the iPhone's accuracy, just another toy to play with but it seems accurate enough for what I need it to do, which is mainly as a quick and dirty check. I would still use my ear(s) to do EQ tweaking but I also think that absurd was simply showing a graph of what he was expecting to see because of the sound he was hearing. If he was hearing subdued lows and no highs, his phone seems like it was showing the same thing, right or wrong. If he was using the graphics to adjust the sound without being able to hear it, he might have been in trouble.

[agedhorse]

The pre and post signals must be time aligned for comparison.

Look at the frequency response for the standard I-phones, there's no way to get any kind of reasonable measurement. Also, these graphs are for one sample, we do not know the variation between samples which can be very large on many inexpensive microphones. When a measurement system (or a part of) is off by 20dB within the desired measurement range, and you are looking to get a system to within ~+/- 3dB, how is this even conceivable?

The latest I-Phones look a lot better, but the variation between models is still >6dB over the measurement range at higher frequencies.

This info is important to those who are interested in learning how things work and what the results really mean and why measurements are done is specific ways.

[abzurd]

 

There are folks here that are trying to understand this stuff and your comments are misleading and inaccurate. I am not being a killjoy, I am placing your comments in context with what is really happening (IMO). I don't know why you are so sour on being accurate? Here's a great example of why you need to know exactly what you are measuring with, the frequency response of the mics and processing on the I-Phones is all over the map and if you thought your mic was even reasonably flat but it really looks like the standard I-Phone mic trace (in red on the comparison graph), you would look like a fool trying to defend any measurement made with this device. Rule number one... know that your measurement tool is actually measuring what you think it's measuring and not something based on inaccurate data. I'm talking about problems that are a factor of 10 inaccurate. I'm not messing around with tiny differences. http://blog.faberacoustical.com/2009/ios/iphone/iphone-microphone-frequency-response-comparison/ I hope this is useful to at least some of you guys who might be exploring an app like this with the intent to tune your system. Know what's a reasonable expectation and what's not.

 

 

From the Six Digital link you referenced:

 

"These mics tend to be very consistent from one unit to the next, and are wide-range."

 

"We have compensated for these mics as much as possible, but given the physics of the situation, the usefulness of the low frequency information is limited." (the mic's have been calibrated by the software.... no not as accurate as a mic by mic calibration, but also not just a naked iphone mic)

 

"in iOS 5, Apple has given us an actual audio session category called "Measurement". This is a huge step forward, even to have Apple acknowledge that audio measurement is a viable subset of audio users.

 

When using this category, (which we have implemented starting in AudioTools 3.7), the limiter is disabled, and we also have for the first time the ability to control the input gain of the built-in mic. This is a huge benefit, and now we can measure dB SPL levels up to (and sometimes over) 120 dB SPL"

 

 

As for the last link you sent, it's irrelevant for a few reasons. It's from 2009 so the last 2 phone models aren't even on there. Also, again, Six Digital has compensated for the microphone deficiencies. Is is perfect, no I'm guessing not. Is it usable? Yes, I believe it is. Again, I've compared to a calibrated microphone and get very similar results. It works for isolating frequencies and ringing out monitors. It helps EQ rooms.