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West
09-17-2012, 08:15 PM
Has anyone used this (True RTA spectrum analyzer)? Its a free download and claims to be able to do a lot.

Looking to see if its legit before I download.

quackhead
09-17-2012, 08:30 PM
Has anyone used this (True RTA spectrum analyzer)? Its a free download and claims to be able to do a lot.

Looking to see if its legit before I download.

Awesome uses..the free download is cool to get the hang of the software, but the paid version is sooo much better(I got the $70 1/6 octave resolution version, IIRC)..takes the place of a few different measurement tools in one program.
The free version is cool for checking SPL, sending various types of signals at any frequency and amplitude, the Oscope is ok, but what you really pay for in a purchase is the resolution of the RTA.

West
09-17-2012, 08:36 PM
Awesome uses..the free download is cool to get the hang of the software, but the paid version is sooo much better(I got the $70 or $80 version, IIRC)..takes the place of a few different measurement tools in one program.

Thanks man! Should I buy a better microphone than the one on my pc? If I can tune this deck I will be a LOT happier.

Or should I maybe try this?
Real Time Audio Spectrum Analyzer,Sound Level Meter,RTA | eBay (http://www.ebay.com/itm/Real-Time-Audio-Spectrum-Analyzer-Sound-Level-Meter-RTA-/120978651909?pt=LH_DefaultDomain_0&hash=item1c2ae3bb05)

quackhead
09-17-2012, 08:43 PM
Thanks man! Should I buy a better microphone than the one on my pc? If I can tune this deck I will be a LOT happier.

Or should I maybe try this?
Real Time Audio Spectrum Analyzer,Sound Level Meter,RTA | eBay (http://www.ebay.com/itm/Real-Time-Audio-Spectrum-Analyzer-Sound-Level-Meter-RTA-/120978651909?pt=LH_DefaultDomain_0&hash=item1c2ae3bb05)

The ebay set up has much better resolution and the mic makes up most of the differences between the 2 software costs. I would say go with the e-bay set up. you will need to purchase a measurement mic and adapters for the TRU RTA to be most effective anyways.

West
09-17-2012, 08:45 PM
The ebay set up has much better resolution and the mic makes up most of the differences between the 2 software costs. I would say go with the e-bay set up. you will need to purchase a measurement mic and adapters for the TRU RTA to be most effective anyways.

Right on man. Really hope this ballances everything, appreciate the advice.

quackhead
09-17-2012, 08:47 PM
Dayton Audio OmniMic V2 Precision Audio Measurement System 390-792 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=390-792)

even better.

West
09-17-2012, 08:54 PM
Dayton Audio OmniMic V2 Precision Audio Measurement System 390-792 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=390-792)

even better.

I'll go with that one then, Thanks.

keep_hope_alive
09-23-2012, 12:07 PM
I'll go with that one then, Thanks.

good choice.

I use TrueRTA constantly. I use a Behringer ECM8000 mic. The only other piece needed is a USB powered mic pre with 48V phantom power. i have two laptop RTA setups - one that uses an expensive SoundDevices USBpre, and another that uses a cheaper Rohls mic pre with an Audyssey PCIMA sound card.

you do want the 1/24th octave unlock feature - that is very useful with identifying resonance issues.

note when taking measurements: move the mic around, in a fig-8 pattern or similar so you even out the phase interference from reflections in the car. that way the measurement includes time and displacement and evens out the response to be more realistic of what the system is doing.

i take full advantage of the 20 memory locations. i have a note pad with me, and i measure each driver separately, then combinations of drivers. i save each one to memory and note what each memory is. then i can go back and investigate. i even used TrueRTA to measure RCA outputs to verify crossover slopes on my HU - and was surprised at what i found!

my build log includes screen shots.

West
09-23-2012, 12:15 PM
good choice.

I use TrueRTA constantly. I use a Behringer ECM8000 mic. The only other piece needed is a USB powered mic pre with 48V phantom power. i have two laptop RTA setups - one that uses an expensive SoundDevices USBpre, and another that uses a cheaper Rohls mic pre with an Audyssey PCIMA sound card.

you do want the 1/24th octave unlock feature - that is very useful with identifying resonance issues.

note when taking measurements: move the mic around, in a fig-8 pattern or similar so you even out the phase interference from reflections in the car. that way the measurement includes time and displacement and evens out the response to be more realistic of what the system is doing.

i take full advantage of the 20 memory locations. i have a note pad with me, and i measure each driver separately, then combinations of drivers. i save each one to memory and note what each memory is. then i can go back and investigate. i even used TrueRTA to measure RCA outputs to verify crossover slopes on my HU - and was surprised at what i found!

my build log includes screen shots.

I always appreciate the advice!

keep_hope_alive
09-23-2012, 12:31 PM
you can buy the ECM8000 for $50 new.

and this (huge sale) to interface the mic with the laptop. thats $80 total!

OSP XLR to USB Microphone Adapter (http://www.siglermusiconline.com/store/pc/OSP-USB-Microphone-Adapter-w-Phantom-Power-p1479.htm?gclid=CLnQ2eGPzLICFao7MgodyB8A6A#.UIgXg6 5IaSo)

i am going to order one right now!

a similar piece:
CEntrance MicPort Pro | Sweetwater.com (http://www.sweetwater.com/store/detail/MicPortPro?utm_source=none&utm_medium=PPC&utm_campaign=none&gclid=CLWD_d-PzLICFYVFMgod-EcACw)

keep_hope_alive
09-23-2012, 12:36 PM
yep. for $30 i just bought a usb powered XLR mic preamp (with phantom power and headphone monitor).

now i can make a third laptop RTA setup!

West
09-23-2012, 12:46 PM
yep. for $30 i just bought a usb powered XLR mic preamp (with phantom power and headphone monitor).

now i can make a third laptop RTA setup!

I picked up the 30$ preamp. I will hunt for a cheap microphone.

keep_hope_alive
09-23-2012, 12:49 PM
Behringer ECM8000 Measurement Microphone 248-625 (http://www.parts-express.com/pe/showdetl.cfm?partnumber=248-625)

or

Dayton Audio EMM-6 Electret Measurement Microphone Allows For Accurate Acoustic Measurements At A Fraction Of The Price 390-801 (http://www.parts-express.com/pe/showdetl.cfm?partnumber=390-801)

keep_hope_alive
09-23-2012, 12:50 PM
FYI - we have 18 of the ECM8000 mics. we use them for all kinds of purposes. they are pretty accurate for the money (compared to our $1500 Earthworks M50)

hispls
09-23-2012, 05:51 PM
I had attempted to play with this. Seems like a great piece of software, but only as good as your soundcard and mic.

I may well order one of those USB interfaces.

keep_hope_alive
09-23-2012, 06:37 PM
Yep, need a good mic and interface. I've used one like this before.m only 16bit but fine for RTA

West
10-01-2012, 11:23 AM
Yep, need a good mic and interface. I've used one like this before.m only 16bit but fine for RTA

Much much better results with the new mic.
Had a few questions, how do you conduct your tuning session? I am using test tones that correspond to my P99RS's eq points. I am sure there is a faster/easier way...

Thanks for all the help thus far!

trumpet
10-01-2012, 03:06 PM
Much much better results with the new mic.
Had a few questions, how do you conduct your tuning session? I am using test tones that correspond to my P99RS's eq points. I am sure there is a faster/easier way...

I use full range pink noise for RTA tuning. I don't have a lot of experience with tuning but it's worked well enough for me and many other installers.

West
10-01-2012, 03:09 PM
I use full range pink noise for RTA tuning. I don't have a lot of experience with tuning but it's worked well enough for me and many other installers.

Do you have any good links where I can DL a file?

quackhead
10-02-2012, 07:57 AM
Do you have any good links where I can DL a file?

if you are using the Tru RTA program, you should be able to just activate the pink noise generator or run a sweep. I use a 1/8"?(I think it is 1/8") stereo to rca adapter from the laptop headphone out tied into my HU Aux rca inputs....two words...Radio Shack

West
10-02-2012, 09:24 AM
if you are using the Tru RTA program, you should be able to just activate the pink noise generator or run a sweep. I use a 1/8"?(I think it is 1/8") stereo to rca adapter from the laptop headphone out tied into my HU Aux rca inputs....two words...Radio Shack
Thanks quack, I'll give that a shot.

keep_hope_alive
10-04-2012, 01:54 AM
I use correlated pink noise (equal energy per octave) and play individual speakers, then combine each side's drivers. then all.

I use Autosound 2000 Disc 102 but the Focal Test Disc 2 has it also.