RTA - Real-time analyzer ...

[- Rovin's car audio -]

http://en.wikipedia.org/wiki/Real-time_analyzer

A Real Time Analyzer (RTA) is a professional audio device that measures and displays the frequency spectrum of an audio signal; a spectrum analyzer that works in real time. An RTA can range from a small PDA-sized device to a rackmounted hardware unit to software running on a laptop. It works by measuring and displaying sound input, often from an integrated microphone or with a signal from a PA system. Basic RTAs show three measurements per octave at 3 or 6 dB increments; sophisticated software solutions can show 24 or more measurements per octave as well as 0.1 dB resolution.

im thinking its a nice tool to have rather than relying on ur ears to tell which freqs in ur system needs tweaking so which is a good 1 to buy & what wud be d price range ? ...

[Soundstream_626]

A couple months ago I bought this

http://www.parts-express.com/pe/showdet ... 1&FTR=EMM6


and this

http://www.amazon.com/Blue-Microphones- ... 866&sr=8-1


together with tru rta / arta / holm impulse software, theres your RTA

theres a soundcard calibration tutorial on diyma and another forum either htguide or avs cant really remember right now.

the emm6 comes with its own individual calibration file and is a bit more consistent than the behringer ecm 8000

[SR]

always a good tool for any installer strongly recommended for tuning

audiocontrol
termlab

[unknown person]

isn't the term-lab have that embedded in the software?

[Team2lo2flo]

^^

but you will need to purchase the RTA mic seperately.

Costs about $3-400 U.S

[- Rovin's car audio -]

ss626 how accurate do u think those u bought are compared to say audio control SA3055\SE ? which is us$1500 ....

[ruffneck_12]

Cud use the trial version of TruRTA, its really cool

I need a good mic doh

[Soundstream_626]

A guy on DIYMA compared both


tru rta and behringer mic (bars) vs audiocontrol represented by red dots. 200hz to 20k doesnt look too far off and also i dont know if that user applied the calibration to his behringer mic which I suspect may give better accuracy below 200. i think the dayton is the better bet.

taken from

http://www.diymobileaudio.com/forum/how ... lls-5.html

The behringer mic has one calibration file for all mics the dayton is individually calibrated. Cross spectrum labs does more accurate calibrations but from the graphs i saw it doesnt look all that different down to 30hz.

[3stagevtec]

Very good info!

I always wanted an RTA but they were always kinda on the expensive side from the ones I saw.. especially for something I will only use a few times..

I didn't do that much research but the only RTA I knew about was this one..

The Dayton Audio OmniMic Precision Measurement System
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=390-790
but that's $300!!

I only now seeing True RTA
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=500-944
which isn't bad for $25..

'arta / holm impulse software' are freeware programs as well.. so that's even better for the average guy wanting to play with an RTA..

[Sully]

I would suggest that you get:
1. Behringer C-2 Microphone ($65 USD for a pair)
http://www.amazon.com/Behringer-C2-Cond ... 715&sr=1-1

2. USB to XLR Converter ($40 USD)
http://www.amazon.com/MXL-MICMATEC-Prea ... 762&sr=8-1

3. True RTA (You can find a torrent for the full version), or pay the $25 retail.

The first two items are basically what you'd pay $300 for from TermLab, but you won't get it in a fancy kit, and you'll have an extra Mic.

I find TrueRTA easier to use and more responsive than the TermLAB software.

[3stagevtec]

If this is the response in your vehicle, 200 - 350Hz would be some EQing.. correct? (Assuming it can't be solved with speaker placement, install etc)

[SR]

actually no
he needs to pull down all the peaks first before boosting the dips

[3stagevtec]

actually no
he needs to pull down all the peaks first before boosting the dips

ohh, makes sense..

[ruffneck_12]

TruRTA pulls alot of resources when you try to max it out though

[pimptacular]

truerta is a pretty neat program
you can check for truerta torrents
ive seen loads of guys on diy reccommend

cross spectrum calibrated mics >> XLR cable >>>M-Audio Mobile pre amp

[Brian Steele]

'arta / holm impulse software' are freeware programs as well.. so that's even better for the average guy wanting to play with an RTA..

\

I don't think HolmImpulse qualifies as an RTA, but in some ways it's actually better for measurement purposes than TrueRTA. For example, it's ability to measure distortion comes in handy, particularly when you want to show someone how silly it is to x-over your likkle front speakers @50 Hz and expect any sort of clean response at higher SPL levels .

[3stagevtec]

Need some help, anyone from south willing to assist me in doing an RTA on my system?

It doesn't make sense for me to purchase a converter / mic / software etc since I only need it for a one time use..

[southside connections]

call me^^ i got what u need

[3stagevtec]

call me^^ i got what u need

great! will call..

[Sully]

I have those services as well, and centrally located.

[3stagevtec]

Comments?

(Ignore the sub bass frequencies, this RTA was done with the sub volume on 1/8.. Front stage is crossed at 60Hz. Midbass drivers in stock door location. Silk dome tweeters midway up in pillars. All EQs were flat. Microphone placed at the driver's headrest.)

[Brian Steele]

Comments?

(Ignore the sub bass frequencies, this RTA was done with the sub volume on 1/8.. Front stage is crossed at 60Hz. Midbass drivers in stock door location. Silk dome tweeters midway up in pillars. All EQs were flat. Microphone placed at the driver's headrest.)

Looks like the tweeters are running a bit too hot (TrueRTA would give you a better idea of how much too hot) and too much off-axis. You may also want to experiment with reversing the phase on the subs. The rest looks like the usual FR wobbles expected from door-mounted front drivers. With that HF FR curve, I'd be tempted to address the 10kHz+ stuff with a pair of Dayton ND16s filtered @10kHz and mounted appropriately. Wait, I already did that .

[3stagevtec]

I forgot to add the the tweeters are crossed at 3600Hz..

Looks like I will need to adjust the angle of the tweeters.. hmm

[Brian Steele]

I forgot to add the the tweeters are crossed at 3600Hz..

Yup, looks like the high frequency "shelf" in the response starts about there. Passive or active x-over? Looks like you've got to drop their relative output by quite a bit.

One more thing - when I do my RTA'ing, instead of just leaving the mike in one location at the headrest, I like to wave it around about where my head's normally located, and use my RTA's averaging feature. I find I get more usable results that way. I use TrueRTA, btw.

[3stagevtec]

Active crossover with adjustable level controls on each output. I lowered the output of the tweeters slightly and added a 2dB boost at 15kHz on my headunit's EQ.

Seems best I invest in a personal mic / and RTA software..

[silent_riot]

That's a very decent no-EQ curve. I would lower tweeter by at least 6dB, toe them in a little more and flip the phase of the sub. With some time alignment, you could try a thing in Rookie SQ. (Seriously)

[3stagevtec]

That's a very decent no-EQ curve. I would lower tweeter by at least 6dB, toe them in a little more and flip the phase of the sub. With some time alignment, you could try a thing in Rookie SQ. (Seriously)

I am looking to get fiber glass pods made for my pillars to better angle the tweets. They are currently facing each other.

Once my schedule is free, I will be passing through at the next IASCA show in Samars for the SQ comps..

[3stagevtec]

Comment...

[kurpal_v2]

wuts in the white box?

[3stagevtec]

wuts in the white box?

I figure you'd notice! lol.. Not my pic..