# Want a portable RTA? It cant get any more portable that this.



## doitor (Aug 16, 2007)

I'll try it a bit later against the "big" one with the M-Audio Mobile Pre soundcard and a calibrated Behringer mic.
Will post some results a bit later.

J.


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## KARPE (Nov 9, 2008)

Link to App?


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## Fixtion (Aug 25, 2006)

i personally use the FFT analyzer from studio six.
i've been preaching there products, but it always goes unnoticed.

the fft doesn't display a graphic such as the rta, but a response similar to the graphs released by speaker companies.

you can adjust the resolution of the response, 1/3oct, 1/12oct, 1/24oct, full octave. it's really an amazing program.


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## doitor (Aug 16, 2007)

KARPE said:


> Link to App?


Studio Six Digital
I have the one called "Audiotools".



Fixtion said:


> i personally use the FFT analyzer from studio six.
> i've been preaching there products, but it always goes unnoticed.
> 
> the fft doesn't display a graphic such as the rta, but a response similar to the graphs released by speaker companies.
> ...


I bought the RTA to try since it was cheaper.
Depending on results with the "big one" I'll get the FFT.

J.


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## Fixtion (Aug 25, 2006)

you won't be disappointed.
have you read about the mic they released?
it take the iphone to a professional level, but of course with a price tag.

give is some time, it they may shave the price. ;]
at least that's what i'm banking for.

ps i'm down for thanksgiving, and we have to demo each others cars! haha


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## doitor (Aug 16, 2007)

Yes, but $250 is a lot of coin.
I built an FFT with my laptop for a lot less than that and this one has two channels that allow me to do impulse response measurements.

J.


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## Fixtion (Aug 25, 2006)

btw, your sub stage is peaking. ;]


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## doitor (Aug 16, 2007)

Fixtion said:


> btw, your sub stage is peaking. ;]


LOL.
That's just an ambient noise measurement.

J.


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## doitor (Aug 16, 2007)

Playing pink noise into a single speaker with both setups 1 meter away.
PC based RTA with calibrated mic.










Iphone with internal mic.










I would say it's pretty damn close for a $9.99 app.

J.


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## timelord9 (Jun 4, 2008)

I've just purchased the FFT app (AUD21), and am looking at getting the ETC app (AUD11) to take impulse measurements. As pointed out above, I would be using these apps with the idea that they will be "pretty good", rather than "pro audio", as i just haven't had enough time to research them. 

However, with a calibrated, proper mic input (such as these) I'd imagine that I should be able to fairly closely replicate a behringer/laptop setup. Cheaper too. 

Be great if the studiosixdigital guys could come on and have a chat about their programs too...


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## StudioSixDigital (Sep 10, 2009)

Hi, 

The Studio Six Digital apps are mine.

One thing to note, the apps are MUCH more accurate on the 3G, compared to the 3Gs, especially below 250Hz. As long as you are not clipping the input, they should be very accurate.

Also, we have some other products in the works that should be helpful, and that cost less than $250 USD.

We have some notes on our web site about the pluses and minuses of RTA vs. FFT.

Studio Six Digital


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## ErinH (Feb 14, 2007)

Thanks for the comparison, Jorge!

If nothing else, this seems like it would be a great app for iphone/itouch users to use simply for level matching on the fly.


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## Fixtion (Aug 25, 2006)

oh, but that's where you're wrong mister bikinpunk, that's where you're wrong.
read up on the literature first, then try it out.


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## ErinH (Feb 14, 2007)

^ frankly, not interested in reading because I can't use an iphone in my area (service drops once you turn down my street). 

Care to breifly explain so I don't have to dig? just for the sake of sharing it.


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## 60ndown (Feb 8, 2007)

trust _*your*_ ears.


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## ErinH (Feb 14, 2007)

60ndown said:


> trust _*your*_ ears.


because by trusting software, we are therefore trusting someone *else's* ears? 

You preach too much. If you didn't rely on software to help you, you'd be typing on a pencil and paper. You would be talking to one of us on the phone. You would be talking in person. You would be pounding images into rock. ie: you wouldn't have near the knowledge or abilities you do.
See my point? 
Quit being so hard up for pressing your 'golden ear gospel' on everyone, Luke. I see it too much. This forum is to *share methods* for tuning. I don't know a single person who tunes solely based on an RTA's results. It's a tool and it's used as one. Furthermore, I don't see you _helping_ the cause or providing anything worth any sort of merit other than "trust your ears" or "that's why I have a 5 band eq in my dash". Okay. We get the point. I'll try to take some time out later to make you a cookie via MS Paint and send it over to you.

If you have a problem with that, simply stay out of these threads. Add your quote above to your sig and go back to OT with your senseless posts. You seem to have a hard time letting people be. I've been dodging even replying to your posts (as there are many times I see you make some senseless comments and threads just like I used to do quite often) for _months_ but damn, man, it's just plain annoying now. Either help or don't, but quit with the replies that do nothing other than show some sort of superiority complex. It's getting old.


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## Megalomaniac (Feb 12, 2007)

StudioSixDigital said:


> Hi,
> 
> 
> 
> One thing to note, the apps are MUCH more accurate on the 3G, compared to the 3Gs, especially below 250Hz. As long as you are not clipping the input, they should be very accurate.



Apple changed the microphone on the 3Gs? I wonder if it was to get rid of any rumblings especially for those people who use the phone while driving


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## 86mr2 (Apr 29, 2005)

bikinpunk said:


> If you have a problem with that, simply stay out of these threads. Add your quote above to your sig and go back to OT with your senseless posts.


What he ^ said!!

Beautifully put.


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## doitor (Aug 16, 2007)

StudioSixDigital said:


> One thing to note, the apps are MUCH more accurate on the 3G, compared to the 3Gs, especially below 250Hz. As long as you are not clipping the input, they should be very accurate.


Welcome to the forum.
Great apps.
My phone is a 3G.

J.


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## Problemhouston (Apr 2, 2009)

Darn it my phone is a 3GS! 

Oh well I am sure you guys will come out with something that will work great for my application.


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## Fixtion (Aug 25, 2006)

looks like doitor and i have quite the investment in our iphones for the mobile audio community.

taking bidders, starting bid price 100.00 USD!
_hehehe, kidding!_


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## DanMan (Jul 18, 2008)

A while back I asked David Navone to suggest an RTA set-up for a diy'er and the iPhone ap was his suggestion.


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## Fixtion (Aug 25, 2006)

i'm constantly promoting studio six, i should be getting paid for it ;]


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## 94VG30DE (Nov 28, 2007)

Now make an app for Symbian S60 please


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## CraigE (Jun 10, 2008)

I just got the Audio Tools App bundle and so far have added FFT. After playing with it for a few days I'm going to add Etc. and Speaker Pop also.
This is one cool toy. :2thumbsup:
I was able to use the the signal generator through my system by simply connecting it to the Ipod dock connector cord, to connect to the HU (Kenwood DNX 9140). By launching the app I could control it through the Iphone. Caution.. make sure the volume control on your system is very low when switching between test tones. As I recall the sine and sq. sine are much louder than the pink or white noise.
This is so much more convenient than using the laptop, especially in a small car.
The reason these apps are sold as a bundle, is so that when the mic becomes available it can be used for all of the modules. Apparently Apple only allows one piece of external hardware per app. 
Well I gotta go play.


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## dannyg (Jan 20, 2009)

wow, this seems nice, too bad i've got the 3GS. ;(


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## aztec1 (Jun 13, 2008)

Damn, I just may go get an iphone now. Beats the snot out of my junk laptop with a billion wires!


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## CraigE (Jun 10, 2008)

dannyg said:


> wow, this seems nice, too bad i've got the 3GS. ;(


I have the 3GS, also. 
The internal mic on the S is supposed to have more roll off below 250 hz.
The Studio Six Website says that there are updates comming to correct the issue.


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## CraigE (Jun 10, 2008)

It just got BETTER.
Smaart Tools is now available as an Audiotools Module for iPhone/iPad
Up to 1/48 Oct. Resolution, and a lot of cool features.

My dishwasher @ 1/6 Oct.









Go here for demo video;
Smaart Tools Single Channel Module | Studio Six Digital


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## 94VG30DE (Nov 28, 2007)

CraigE said:


> It just got BETTER.
> Smaart Tools is now available as an Audiotools Module for Iphone
> Up to 1/48 Oct. Resolution, and a lot of cool features.
> 
> ...


That's a pretty good looking F/R for a dishwasher. What EQ are you using?  

The church just got an ap for the iPad that looks almost identical to this. I'll have to look into what it is, and then post some results once I get to play with it a little.


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## CraigE (Jun 10, 2008)

The app is made for iPad/iPhone, and I think for the iPod Touch.
Same app for all devices.

They demo it on the iPad in the second half of the video.

This will be great on the iPad with the larger screen. 
I'm holding out for the next generation iPad that is rumored to have usb as well as cameras front and rear.
The usb will make it much easier to connect a measurement mic, although a mic can be connected to the current iPad through the camera kit.

The Audiotools/Studio Six Digital customer service is excellent. Andrew Smith, the owner, responds to emails immediately, even on weekends and holidays.


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## erknjerk (Dec 24, 2010)

How's the iPhone 4 with this? I picked one up today and still got my 3G. My wife has a 3GS, but my buddy wants to buy my 3G. Does the new software fix the 3GS and iPhone 4?


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## s4turn (Jun 17, 2009)

theres quite a few RTA programs onthe app store.

so the smaart tools one is the best? or is their better? has anyone done a comparison?

and I also have a iphone 4, is there any that work better with this?

I assume the 4 has a better mic than the 3gs?


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## CraigE (Jun 10, 2008)

According to the website, the built in mics use filters that cause a low frequency roll off below 250hz to some degree. This is to help prevent wind noise during normal phone conversation.
The apps have compensation filters to correct for this.

I'm using the iAudioInterface (and measurement mic) that bypasses the internal mic and filters.

iAudioInterface; iAudioInterface Technical Details | Studio Six Digital


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## BigRed (Aug 12, 2007)

I like studio six the best. The rta porrtion alone has a weight, c weight, and unweighted, as well as being extremely easy to use. Go deeper and there is actually a module that will allow u to test speaker delay.


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## DBfan187 (Feb 26, 2010)

any of these avail for Android?


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## BuickGN (May 29, 2009)

DBfan187 said:


> any of these avail for Android?


I just did RTA Pro analyzer for my Droid II Global. Haven't tried it out on the car yet but it's pretty neat.


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## BuickGN (May 29, 2009)

BuickGN said:


> I just did RTA Pro analyzer for my Droid II Global. Haven't tried it out on the car yet but it's pretty neat.


Probably won't be trying it out today. Drove to the parents' house to pick up my test tone CD that my father had borrowed. His answer was I have no idea where it could be without even looking. Note to self, parents will never borrow anything again.

The program is pretty neat but it sucks not being able to actually try it out.


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## CraigE (Jun 10, 2008)

The Audiotools Apps, which Smaart Tools is a module within the app, have a tone generator that includes pink and white noise, sq waves, and sine waves from 5 to 20k hz. The sine waves will sweep, or can be set , which is great for locating resonating panels.

Can't you use this ?
A quick search showed a free noise and sweep generator for Android, that can be burned to CD.
Noise and Sweep Generator - Android


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## DBfan187 (Feb 26, 2010)

BuickGN said:


> I just did RTA Pro analyzer for my Droid II Global. Haven't tried it out on the car yet but it's pretty neat.


Thanks bro! Just got it off of applanet(woot free apps)

Now I just need to compare it to my laptop setup with TrueRTA.


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## BuickGN (May 29, 2009)

DBfan187 said:


> Thanks bro! Just got it off of applanet(woot free apps)
> 
> Now I just need to compare it to my laptop setup with TrueRTA.


Really looking forward to the results!


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## DBfan187 (Feb 26, 2010)

might be a while bro, it's a bit nipply outside at the moment lol


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## michaelsil1 (May 24, 2007)

BigRed said:


> I like studio six the best. The rta porrtion alone has a weight, c weight, and unweighted, as well as being extremely easy to use. Go deeper and there is actually a module that will allow u to test speaker delay.


Does it also do averaging?


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## ErinH (Feb 14, 2007)

I'd like to know if it'll let you average response of multiple measurements. 

I'd also be curious if this allows for binaural measuring. I know the mics will need external power, but some software simply doesn't even allow input from more than one channel.


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## BuickGN (May 29, 2009)

I think mine is somewhat basic but it was fun trying it out. 

I'm not sure if this is a Droid issue or a car issue. With any sort of volume at 30hz the entire band lights up. At low volume it does not happen. Would this be a mic issue or is it the interior rattling?


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## CraigE (Jun 10, 2008)

bikinpunk said:


> I'd like to know if it'll let you average response of multiple measurements.
> 
> I'd also be curious if this allows for binaural measuring. I know the mics will need external power, but some software simply doesn't even allow input from more than one channel.


You can average, but it is different (I think) from the way it's done with TrueRTA
Audiotools RTA and FFT gives you a range of decay time,peak hold, and average.
Smaart Tools gives a range of decay time and infinite. The infinite mode will continually average for any length of time. use it to gather a sonic signature over time. It can be paused and restarted, to reset, select inf again.
The average mode in Audiotools works similarly, if not the same.
I use this mode, and move the mic around my head/ears.



As far as binaural mics go, I want to use them also, since I have the in-ear mics and Pureaudio usb soundcard from Sound Professionals.

The iAudioInterface Manual says that you can use your own microphone,as long as you can supply a signal to the line input of iAudioInterface. You may need your own phantom power supply, or microphone preamp. To calibrate your microphone, you will need a microphone calibrator.
The diagram in the manual shows the line input going to both the left and right inputs of the iDevice. The mic input (for the single measurement that comes with iAudioInterface) only goes to the left input. 

I'm looking for recommendations/info for a mic preamp and mic calibrator.
Hopefully, the next gen iPad has usb and I can use the Pureaudio piece.
And the screen size of the iPad will be nice to work with.


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## ErinH (Feb 14, 2007)

CraigE said:


> As far as binaural mics go, I want to use them also, since I have the in-ear mics and Pureaudio usb soundcard from Sound Proffessionals.


Yea, I need to try the camera connector for the ipad to see if it will allow for usb power on the binaurals...

The real problem, however, is simply if this program allows for measuring both left & right channels at the same time. If not, then you're probably defaulted to the left channel (or right channel) and thus measuring mono... which with binaural mics is a bad deal. Just defeats the purpose. I'll have to probably email these guys and see what they say about it.


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## CraigE (Jun 10, 2008)

I was editing my previous post to be a little more clear.


"The diagram in the manual shows the line input going to both the left and right inputs of the iDevice. The mic input (for the single measurement that comes with iAudioInterface) only goes to the left input."
See page 5 of the user manual; http://www.studiosixdigital.com/downloads-2/iaudiointerface_user_guide1.pdf

It looks like you can get both left and right into the iDevice, so that's a start.
I will keep researching.

What about mechanically summing the binaural mics with a mono male to 1/8" stereo female adaptor ? 
I've done this, just for kicks, and I definitely get input from both mics into one channel.


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## ErinH (Feb 14, 2007)

CraigE said:


> What about mechanically summing the binaural mics with a mono male to 1/8" stereo female adaptor ?
> I've done this, just for kicks, and I definitely get input from both mics into one channel.


Yea, man, I was actually thinking about this last night... should work. Problem is still getting power for them. 


Last night I tried the following and had no success:
1) Mobile Pre (requires too much power)
2) Mic Mate XLR adapter (requires too much power)
3) Andromeda (this is the piece I use to provide power to my binaural mics and also allows for stereo input recording). Requires too much power.

The power issue could be fixed with a powered USB hub, but that defeats the whole purpose to me. If I have to carry that around and find wall power for it, I might as well just use the laptop. The video below has a pretty good solution for still remaining mobile, though.

Next on my list is to simply order a battery pack for the binaurals and go into the ipad's input. Or, try this imic adapter, which likely doesn't provide enough power to the mics, but who knows. I'll try to pick it up locally and try it out. 
I really wish the iaudiointerface worked with the iphone4 or ipad. But, it doesn't and apparently will never be made to do so, according to their website. I'd buy that rig in a heartbeat... it does impedance sweeps, THD, etc, etc... though it gets expensive. Although, I could ditch my own RTA rig and go that route if it did work. I just don't desire to step back in products to get the ability to use the iaudiointerface.

I did send them an email about whether or not their software even records in stereo or if it defaults to a single channel. But, after testing last night, I realize it probably doesn't matter at this point. We'll see, though.


Here's a good link with what has and hasn't worked:
http://blog.faberacoustical.com/2010/ipad/usb-audio-devices-that-work-with-ipad/


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## ErinH (Feb 14, 2007)

did some further searching and it appears iOS 4.2 is to blame for lack of power:
iPad USB Compatibility | Studio Six Digital

I may even try reverting back to a previous version, but I'd rather try to get something working with the current iOS.


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## CraigE (Jun 10, 2008)

The internal mic (of ipad/iphone) is subject to filters that help prevent wind/pop noise. Any mic that plugs into the headset jack will also be subject to the filters.
For headset input, and internal mic measurements: iPad Audio Input Options « Faber Acoustical Blog


Audiotools does have compensation filters to help correct for this.

I'm currently using 3gs and iAudioInterface.
iAudioInterface bypasses the built-in filters, and IME the results are much more accurate, especially below 250hz.

It's my understanding that ipad/iphone4 does not support analog-in at the dock.


The screen size of the iPad is ideal for the Audiotools Apps. Man it would be great to use my binaural mics, and get direct input, to bypass the built-in filters.


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## BigRed (Aug 12, 2007)

CraigE said:


> The screen size of the iPad is ideal for the Audiotools Apps.


yes it is


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## CraigE (Jun 10, 2008)

I've found several devices that are "on the horizon" to get high quality audio into the iPad.

This one from Alesis got my attention, and it probably won't be cheap.
Looks like it comes with a power supply. Maybe a 12v cig lighter is an option.
It also has phantom power.


"Connect all your pro audio gear to virtually any app in the App Store with the iO Dock."

https://www.alesis.com/iodock


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## ErinH (Feb 14, 2007)

I'm willing to bet you'll still need external power for this. I've not seen any product that can provide phantom power (48v) to a mic on the ipad due to the weak voltage output of the dock connector. Everything I've tried and even researched still needs some sort of external power. 
To me, that gets back to the point of necessity. If I have to have external power, then I'm back in the laptop/netbook game. 

Although, that duracell usb power device I linked above does look pretty handy.


As far as binaurals go, I'm still awaiting the answer to how the studiosix software treats the input of them. If it only takes one channel (typically Left on most rta programs, by default) then there's no sense in bothering. 
So, there are a few things left to figure out:
1) Power
2) Which input to use

If you can use the stock input and get stereo input, then applying external power via battery pack is the key here.
If you have to use another input to get stereo recording (such as the iMic I linked above), then you should still be able to use this and just use a battery pack for power. 

I know for a fact the andromeda usb stereo recorder does not work as it doesn't get enough juice from the ipad. That sucks.


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## CraigE (Jun 10, 2008)

The Alesis device that I linked definetly requires external power.

A few things that MAY indicate that Audiotools will work with stereo input.

1- the app comes with a recorder that will record in mono or stereo.
2- When using your own mic with iAudioInterface, you supply a signal to the line input, which allows you to choose mono, or stereo mics.
3- another tool in the app is Audioscope. Scope Setup allows you to choose left and right as an input source. "the mic is normally the left input a dock adaptor is required for the right input"

I'm interested to hear the response from from your email to StudioSix Digital.


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## ErinH (Feb 14, 2007)

interesting. 

at worst, we can test it ourselves. that just requires buying all the stuff to test it with, such as the battery pack and then determining if we need to go through the dock or if we can use the headphone/mic input to get stereo recording.


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## Wheres The Butta (Jun 6, 2009)

Any android users want to chime in with their research?


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## CraigE (Jun 10, 2008)

bikinpunk said:


> interesting.
> 
> at worst, we can test it ourselves. that just requires buying all the stuff to test it with, such as the battery pack and then determining if we need to go through the dock or if we can use the headphone/mic input to get stereo recording.



Hope to test it out soon.
I have this battery powered preamp, and patch cords, on order from The Sound Professionals;

USB Microphone, Stereo Microphone, Preamplifier, Digital Recorder, Custom Cables and more at Rock Bottom Prices from The Sound Professionals - Great deals on Microphone, Preamplifier, Digital Recorder, Cable and more!

This will input stereo to the line input of iAudioInterface which then connects to the dock of 3gs.



Everything I've read PRECUDES STEREO in, from the HEADPHONE MIC INPUT, on iPad/iPhone. 
The headphone mic input does NOT bypass the iPhone/iPad built-in wind/pop (Hi-pass) filters.

Link for iPhone/iPad built-in mic and headset mic input FR measurements;
iPad Audio Input Options « Faber Acoustical Blog


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## ErinH (Feb 14, 2007)

why did you go with that unit over something like this:
USB Microphone, Stereo Microphone, Preamplifier, Digital Recorder, Custom Cables and more at Rock Bottom Prices from The Sound Professionals - Great deals on Microphone, Preamplifier, Digital Recorder, Cable and more!

just curious. that's a pretty big price difference.


and, since everything you've read says stereo input won't work, what results are you expecting? Are you simply testing the notion that this is true, or do you have an idea for working around it?
Or, are you going with a dock connector setup that allows for stereo recording, like the iMic I linked above.
I'm curious to see your results.

Edit: nevermind, i didn't see the iAudiointerface portion. Sucks for me and iphone 4 users... the iaudiointerface cannot be used on these units. 
I'm personally trying to find a way to make this setup work with the iPad, but would still be interested in seeing your results.


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## CraigE (Jun 10, 2008)

Looks like the power supply you linked will work, and I like the price.
I spoke with Chris at The Sound Professionals when ordering, he was familiar with Audiotools, and looked at the manual for iAudioInterface.
I'll give him a call, see what he says, and may exchange it. Thanks!


We aren't the only ones interested in "stereo audio in" for the iPad/iP4.
Just do a search of "iPad audio in".
Some comments speculated that Apple may even remedy this via updates and/or hardware, others said it will be available with iPad2/iPhone4s.


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## ErinH (Feb 14, 2007)

glad I could help.
that's actually the one i've been intending to purchase, but I'll let you be the guinea pig this time. lol.


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## Irishdrunk (Feb 22, 2011)

AudioTools is very nice app, but the in-app purchases add up quickly.


I'm not gonna go any farther in my explanation, atleast not publicly posted (PM me if you must)
But a Jailbroken Iphone is the way to go with this.
Also check this one out SignalScope Pro for iPhone, iPod touch, and iPad on the iTunes App Store
It's 80 bucks, but like I said, jailbroken iphone.....ya.
It has an FFT signal generator and o-scope.


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## big_ears (Sep 21, 2010)

I'm trying to sort some problems with my system and bought Audio tools by studio six as it looked solid. It is. The problem is I can't output any generated signals through my dock to my brand new head unit! The signal is sent at a 48K sample rate (just emailed with Andrew over there) which my head unit accepts, but I guess the DAC can't process it for some reason. I have the new Sony XNV 770bt and ipod touch 4 with usb connection.

Anybody know anything about this? I see others have outputted signal to their head unit (via usb). Why can't I? Does any one else have or heard about this problem? For $20 its an awesome package but I can't use the best stuff! I mean I can, but in a pain in the a$$ way.:mean

Note: I've now tried SignalScope Pro as well with my head unit using ipod cable/usb. No dice. Head unit cannot process generated signal. Wonder what that means in terms of my regular listening experience. Do I have an inferior DAC or one that just can't handle this particular test signal?


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## big_ears (Sep 21, 2010)

*wide discrepencies between "good" RTA apps.*

I wanted to post some screen shots from from my use of the Studio Six RTA and SignalScope Pro with my ipod touch 4g. There are WIDE discrepancies in the results. All graphs are resultant of a Pink noise MP3 playing through my system front right speakers. The ipod was placed on my center console armrest in the same place/alignment for all screen shots.

The volume was slightly louder when the Studio Six shots were taken ( 4 points on a 50 point scale) but it should not matter much for the basic shape of the "curve". I had with the decay settings on 1/2 sec i believe and the SPL unweighted. I played with the decay function a bit, taking more screen shots than I am posting, and the basic shape of the "curve" was very similar. With SignalScope Pro the decay was set to fast with an unweighted SPL measurement.

If anybody _wise_ sees this, what do you think? Holy discrepancies!!?? I like the SignalScope data better and have at least one reason to believe it is more accurate. As I sit here in my living room with movie dialog in the background, just talking, no music, the 1st bar in RTA by Studio Six shows hella bass. Just like in my graphs, the 1st bar (bass end) is above the subsequently higher frequency bass bars. Thats wrong. How could a quite room except for movie dialog have a bass spike right at at lowest end of the scale? This is actually always the case, even with the movie off, in a silent room as I just tried it. The SignalScope wins I a say as it shows no "PHANTOM BASS"!


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## Irishdrunk (Feb 22, 2011)

*Re: wide discrepencies between "good" RTA apps.*



big_ears said:


> I wanted to post some screen shots from from my use of the Studio Six RTA and SignalScope Pro with my ipod touch 4g. There are WIDE discrepancies in the results. All graphs are resultant of a Pink noise MP3 playing through my system front right speakers. The ipod was placed on my center console armrest in the same place/alignment for all screen shots.
> 
> The volume was slightly louder when the Studio Six shots were taken ( 4 points on a 50 point scale) but it should not matter much for the basic shape of the "curve". I had with the decay settings on 1/2 sec i believe and the SPL unweighted. I played with the decay function a bit, taking more screen shots than I am posting, and the basic shape of the "curve" was very similar. With SignalScope Pro the decay was set to fast with an unweighted SPL measurement.
> 
> If anybody _wise_ sees this, what do you think? Holy discrepancies!!?? I like the SignalScope data better and have at least one reason to believe it is more accurate. As I sit here in my living room with movie dialog in the background, just talking, no music, the 1st bar in RTA by Studio Six shows hella bass. Just like in my graphs, the 1st bar (bass end) is above the subsequently higher frequency bass bars. Thats wrong. How could a quite room except for movie dialog have a bass spike right at at lowest end of the scale? This is actually always the case, even with the movie off, in a silent room as I just tried it. The SignalScope wins I a say as it shows no "PHANTOM BASS"!



The Studio Six site did mention a compensation filter for idevices after the 3g, because apple changed the mic to have a huge rolloff below 250hz, to cut out wind noise and what not. I assumed that is why the AudioTools RTA showed so much low end, even sitting in my living room. Maybe Signalscope pro found a workaround for this?
Both apps have good tools, but the in app purchases on AudioTools will kill a guy, since even jailbreaking can't get you those


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## big_ears (Sep 21, 2010)

*wide discrepencies between "good" RTA apps.*

Just for the record I wanted to post some screen shots I took last night before I fell asleep in a quiet room/House (Below). There may have been the hum of the refrigerator in the back ground, but I was in the bedroom and it was basically quiet.

Once again crazy phantom bass. All I got to say is at least for my ipod touch 4g the built in bass compensation seems off. I'm love to see some posted silent room screen shots from any iphone generation or preferably all generations to see if they have a similar problems. I mean if the later generations iphones have the same innate screwed up calibration as mine thats pretty lame. The compensation mechanism could be mis-designed. 

In addition, I'd love to run my car with a legitimate RTA just to see which of these is more accurate out of the box for my ipod touch beyond the phantom bass. From what I can see, beyond how the zoom of the graph accentuates it, there is a wider db gap between 500hz peak and 4K dip with Studio Six (approx. 17 db average) than with S.S.Pro (approx. 10 db average){Some Sample Pictures Above} I should probably take all shots again at the exact same volume to confirm this point, and may, but I fairly certain there is a wider db swing shown in studio six than S.S.P.

And curiously, with the studio six after looking at all the images I took (eleven, 3 silent shots), the low point on the higher frequency side of the graph is ALWAYS at 4K EXACTLY! With S.S.P. it moves around as evidenced in the shot posted below compared to the similar one above. Seems a little suspect with live testing as well. If music has 4K info the bar pops up nicely, but in general 4K tends to be the lowest point on the upper half of the graph. Just listened to a song with bells and 4K band was riding high, but generally low point as evidenced in silence shot below.


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## CraigE (Jun 10, 2008)

I just got the iPad 2, and was able to connect a DBX Measurement Mic, with an MXL Mic Mate USB Preamp, using the method linked below.
It uses a rechargeable battery (around $25 at Rite Aid), so no need for 120v AC.
You need a USB cord with A-Male to A-Male. They are not readily available at the usual places like Best Buy, but can be found online at Amazon.

iPad as a portable RTA analyzer - Gearslutz.com

The iPad 2 is VERY FAST, and looks to be an excellent platform for portable testing programs.
The screen real estate makes it so much better (for me) to use than the iPhone screen. It's easier on the eyes, and my fat fingers trying to slide a cursor.
One thing I noticed was that the screen still says "Internal Mic" even though I selected "Dock Mic". But the readings were definitely through the dock mic.

Screen shot of my C6 system playing stereo pink noise at 1/6 octave resolution.
Using the Smaart Tools Module of the AudioTools App


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## The Tube Doctor (Nov 24, 2009)

Try this one for Android.
Currently running on my HTC Desire HD.
Hacked a passive mic to input on the headphone jack.
Free version is 1/3 octave, paid version offers up to 1/12 octave.

https://market.android.com/details?id=radonsoft.net.rtapro

Same company has a signal generator app for Android.
I output from phone (again, headphone jack hack) to RCA.

https://market.android.com/details?id=radonsoft.net.signalgen

Also, Sound Form is another signal generator that I've got on my HTC.

SoundForm Signal Generator - Android

So far, I'm being a cheap SOB and only using the free versions. All this smart phone 
tech is new to me, so I didn't want to fork over the $$ without a comprehensive shake-down test. I'm sold.


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