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-   -   TrueRTA-for-dummies (https://www.avsforum.com/forum/91-audio-theory-setup-chat/572477-truerta-dummies.html)

mpsmps 01-09-2007 01:49 PM

Quote:
Originally Posted by philip miller View Post

I have completed purchase and installed Level 4 of RTA and, using a Behringer 8000 microphone along with a Soundblaster Live USB card on my pc, I began taking measurements of my room. The response graph that I end up with has various steep vertical spikes, for want of a better term, throughout the range. What am I likely to be doing wrong. Thanks in advance for your help. Phil Miller

Hi Philip,
Creative automatically maps the line-out into the line-in for game effects. If you go to the FAQ on the TruRTA website, you'll see a question about calibrating with the Audigy containing directions on how to fix that problem.

Mike

wiz561 01-17-2007 11:06 AM

Quick Question... TrueRTA looks like something I am looking for. But once you get done running all of the tests as outlined in the first post, what do you do next?

As you can tell, I'm just trying to learn about this. I'm guessing that you want to adjust your equalizer so that dB SPL is 'flat' across all frequencies when it does the sweep. By flat, I mean as flat as possible. At this point, everything is correctly adjusted.

Am I on the right path or WAY OUT in left field?

Thanks!

josh1233 01-17-2007 12:33 PM

I've been thinking about getting the TrueRTA for a while (I have an old Audio Control RTA and a Coustic RTA). I am wondering what cables I would need if I am going to use the M-Audio MobilePre USB Portable Audio Interface and the Behringer ECM8000 Microphone with TrueRTA and a laptop?

- I guess I would need a XLR (1 male end/1 female end) to run from the mic to the preamp.
- USB cable to run from the laptop to the preamp.
- mini headphone jack on both ends to run from the stereo mic input to the stereo line output on the MobilePre for calibration?
- and what cables to run out of the MobilePre to the amp (dual RCA and the other end 1/4" jack?)

help would be greatly appreciated,
Josh

josh1233 01-17-2007 01:10 PM

donovanhebard, did you get your issues worked out?

When setting up the audio system in a car, you should EQ each side of the car separately (provided your EQ has separate adjustments for right and left and you are trying to get the car to sound good from both the driver and passenger side). After the initial setup of each channel, check both together (stereo). Do not boost any frequencies when adjusting both channels together, only cut frequencies. Try using both correlated and uncorrelated pink noise when EQing each channel separately and together. Set the EQ at an average between the 2. Do a lot of listening to well recorded audio tracks between EQing (like something from Sheffield Labs). And don't try to go for a flat (straight line) curve. Just get rid of peeks and dips. To do this properly, it will take a lot of time over the course of a week or two, depending on how flexible your processors are.

Before you do any of this you should set your gains from each piece so that the signal does not clip, then when you get to the amp(s), set the max amp gain to a 3:1. In other words, set the amp gain to just below clipping, read the voltage, then multiply that by three and set the amp gain to that, then cut the gains from amp to amp to balance the sound. Also, the xover points and slopes should be set before EQing to get the car sounding as good as possible. The EQ is only used to smooth thing out.

Also, make sure that, if you have time delays, they are turned off before EQing the car (they should be the last thing set). You will probably end up with a small dip at 250hz-400hz that can not be entirely corrected (if you are running speakers in the doors).
*Kick panels would be better to eliminate cancellation, would widen the sound stage, and decrease the path length differences of the right and left channel.

Another trick that may help, before eqing. If your sound stage is low, try reversing the polarity of one channels tweeter and the other channels mid. I know it sound wrong, but it usually bumps the image up about a foot. And with the amount of reflection points in the car audio environment, it will most likely focus the image better and you should not notice any loss in the mid-mid bass range that one would expect from doing this. Also, it should help the center image from both the right and left seating positions.

WSLam 01-30-2007 01:24 PM

Does anyone know how to create a 'loop' for the Apogee Mini DAC and Mini ME? I am using an ECM8000 and have the Apogee combo, but I can't figure out how to get it to work! Can anyone help? Thanks.

tsound 01-31-2007 09:59 PM

I have a problem with TrueRTA when used with a Soundblaster Live! 24 USB. The program crashes after pushing the "Stop" button. It starts fine, the tone generator works fine, but as soon as "Stop" is pressed the program crashes. Anyone seen this before?

tsound

jaegertc 02-20-2007 12:31 PM

Quote:
Originally Posted by tsound View Post

I have a problem with TrueRTA when used with a Soundblaster Live! 24 USB. The program crashes after pushing the "Stop" button. It starts fine, the tone generator works fine, but as soon as "Stop" is pressed the program crashes. Anyone seen this before?

tsound

If you haven't, try the REW/BFD forums at HomeTheaterShack.com. They have several threads dedicated to REW (and RTA?) and at least one to getting room eq software to work nicely with that soundcard.

audiozealot 03-19-2007 11:44 AM

Is there a way to splice together 2 graphs in TrueRTA? I am trying to splice together a near field measurement of the woofer with a far field measurement for a better representation of the frequency response of a speaker. I see how to shift the curves but is there a way to delete the unwanted pieces of the curves at let's say 300Hz? Please don't make me go into Paintbrush and delete pixels

Thomas-W 03-20-2007 05:20 PM

You can't splice but if you save each one to a different memory setting, you'll see the two plots combined.

andybdjuk 03-22-2007 01:39 PM

Hi guy's I have read all the post and hope I have not missed the answer to my question. I have an M-Audio USB Portable Audio Interface and the Behringer ECM8000 Microphone with TrueRTA and a laptop?

I set it up last night in my club to monitor the SPL across the spectrum of a band that was playing.

I have cal'ed the interface flat but later noticed that the clip light was coming on. Turning down the input gain obviously changes the SPL graph. Could somebody give me any pointers and what I am doing wrong? And how I set it up correctly

Thanks in anticipation

Andy

karos 04-22-2007 06:21 AM

how is trueRTA different from RoomEQ? Isnt it the same author?

sorry-I just notice that one is John Murphy the other is John Mulcahy. But how are these apps different?

jonleelk 04-23-2007 04:48 AM

Just set up TrueRTA on my acer laptop equipped with onboard Realtek HD audio. The FR for the realtek is quite bad, started to slop down from 100Hz downwards. However, TrueRTA was able to equalised to a almost flat line when using calibrating sound card option.

Is this result accurate enough to use, or should I add an external PCMCIA Sound Blaster® Audigy® 2 ZS Notebook which is supposed to have a Frequency Response (+/-3dB, 24-bit/96kHz input) = <10Hz to 46kHz (2V Rated Output)hae a FR of +1 3dB

taiguy 04-25-2007 11:03 PM

I've got a Behringer ECM8000 microphone running to a Mackie 1202-VLZ mixer/preamp to Audigy 2 ZS notebook. I tried following the directions in the pdf file off of TrueRTA's website but they're for an older version of the creative software and I can't find the same options available. It shows in my sound system calibration test. Can anybody please explain in detail how they got their Audigy 2 ZS card to work properly with TrueRTA? Thanks.

mitchlampert 04-26-2007 10:09 AM

Will True RTA run on Windows Vista?

catapult 04-26-2007 10:56 AM

Quote:
Originally Posted by taiguy View Post

I've got a Behringer ECM8000 microphone running to a Mackie 1202-VLZ mixer/preamp to Audigy 2 ZS notebook. I tried following the directions in the pdf file off of TrueRTA's website but they're for an older version of the creative software and I can't find the same options available. It shows in my sound system calibration test. Can anybody please explain in detail how they got their Audigy 2 ZS card to work properly with TrueRTA? Thanks.

These instructions for running the 2 ZS with Praxis are over a year old but maybe they will help.

http://www.libinst.com/Audigy%202%20...h%20PRAXIS.htm

scotland60bwork 05-17-2007 01:21 PM

Hi all -

I have TrueRTA full, ECM8000 mic, MobilePre USB, and the digital RS SPL meter. I've downloaded all cal files from this site. I perform the sound card cal with a loop from the line out 1/8" jack to the ch1/line 1/4" jack with adapter. I am able to get a flat line and do not appear to get any clipping. In the MobilePre audio control panel in Windows, I have the USB Record and Output sliders maxed and the monitor slider muted. Additionally, I keep the knobs on the front of the MobilePre at midposition.

After sound card cal, I hook up the SPL meter to ch1/Line and perform the absolute SPL cal, with the RS SPL meter cal file in use. This appears to work well. However, when I then proceed to hook up my ECM8000 and change the cal file to the ECM8000 file I got from this site, the SPLs appear to be pretty far off, usually about 5-10 dB difference.

I also set up the SPL meter on ch1 and the ECM8000 on ch2 and I have the same problem, even if I change the cal files. I find it hard to believe the cal files would be so far off.

Is there something that I'm missing?

Please help!

Cheers
Scot

Richard Mayer 05-21-2007 04:57 PM

Quote:
Originally Posted by scotland60bwork View Post

Hi all -

I have TrueRTA full, ECM8000 mic, MobilePre USB, and the digital RS SPL meter. I've downloaded all cal files from this site. I perform the sound card cal with a loop from the line out 1/8" jack to the ch1/line 1/4" jack with adapter. I am able to get a flat line and do not appear to get any clipping. In the MobilePre audio control panel in Windows, I have the USB Record and Output sliders maxed and the monitor slider muted. Additionally, I keep the knobs on the front of the MobilePre at midposition.

After sound card cal, I hook up the SPL meter to ch1/Line and perform the absolute SPL cal, with the RS SPL meter cal file in use. This appears to work well. However, when I then proceed to hook up my ECM8000 and change the cal file to the ECM8000 file I got from this site, the SPLs appear to be pretty far off, usually about 5-10 dB difference.

I also set up the SPL meter on ch1 and the ECM8000 on ch2 and I have the same problem, even if I change the cal files. I find it hard to believe the cal files would be so far off.

Is there something that I'm missing?

Please help!

Cheers
Scot

That's because the RS SPL meter and ECM8000 have different output voltages. You can't calibrate the absolute SPL with another and then simply switch to another.

Instead you should hook up the ECM8000 and monitor the SPL with the RS SPL meter. By monitor meaning holding the SPL meter right next to the ECM8000 and checking the SPL it shows. Then enter that SPL into TrueRTA.

scotland60bwork 05-22-2007 12:39 AM

Thanks Richard!

I was able to calibrate the SPL by holding the RS meter right next to the ECM8k. I just didn't know whether this was a valid method of calibrating it or not, and wondered what the reason was for the difference. I guess this is the only way I can do it then. Thanks for the help!

JimP 06-06-2007 09:03 AM

Quote:
Originally Posted by mitchlampert View Post

Will True RTA run on Windows Vista?

Does anyone know??

DrFeelgood 06-14-2007 09:39 AM

Hi there - newbie to all this very technical stuff, and come from the world of ICE

Could someone hold my hand, and walk me through the most simple setup of TrueRTA? At present, I'm only using it for spectrum analysis in a car for the purposes of equalisation/crossover setting. I thought I'd better get that confession out of the way first :redface: I promise to learn more of its features later! The kit seems to be the standard recommended stuff from reading this thread - ie laptop, M-audio mobile pre and a Behringer ECM8000. I got lost when you reached the word loop...

Many thanks!

Richard

eugovector 06-14-2007 10:07 AM

Quote:
Originally Posted by DrFeelgood View Post

Hi there - newbie to all this very technical stuff, and come from the world of ICE

Could someone hold my hand, and walk me through the most simple setup of TrueRTA? At present, I'm only using it for spectrum analysis in a car for the purposes of equalisation/crossover setting. I thought I'd better get that confession out of the way first :redface: I promise to learn more of its features later! The kit seems to be the standard recommended stuff from reading this thread - ie laptop, M-audio mobile pre and a Behringer ECM8000. I got lost when you reached the word loop...

Many thanks!

Richard

If you're completely new, Room EQ wizard might be a better place to start. Great help file, and free.

mitchlampert 06-14-2007 10:35 AM

Quote:
Originally Posted by mitchlampert View Post

Will True RTA run on Windows Vista?


Yes it will but the drivers for the M-Audio will not. So I had to use an older laptop to get it running.

mitchlampert 06-14-2007 10:39 AM

One more question. Can I use the pink noise generator in my processor for the tone or do I have to use the tone generator in the RTA program?

freythman 06-22-2007 09:00 PM

Has anyone had experience with the Alesis MultiMix 8USB Mixer? It's the same price as the M-Audio MobilePre, except its an 8 channel mixer with 4 XLR inputs, each with phantom power. It just seems like I'd be getting more bang for my buck...

Here's what I'm considering for my RTA techie package:

TrueRTA Level 4 (no brainer)
Behringer ECM8000
Either: MobilePre OR Alesis Multimix

Calvary 07-14-2007 08:16 AM

Good Day All,

I have read all the replies on this thread and have found it quite interesting. I will admit that I am brand spanking new to this so I apolozige if my questions seem to waste your time.

My church santcuary is in an industrial warehousing unit that is a 50'W x 50'L x 24'H. We have flat surfaces all over the place (all of the walls are drywalled with no insulation, the roof is corrugated metal with trusses, the floor is concrete covered with industrial carpet)
The dimensions and physical properties of the room make it a real challenge to get "proper" sound. I am investigating several methods of sound treatment, however I would also like to tune the room.

Question: Will TrueRTA work for a room this large? I am looking to purchase the M-Audio Mobilepre and the Behringer ECM8000 along with a Radio Shack SPL meter. ---> are these compenents suitable for tuning and profiling my santuary? Would I the church mixer in this setup?

Thanks in advance.

Rayjr 07-21-2007 08:45 AM

Hello all
I was wondering if TrueRTA can do energy time graphs.

Thanks
RayJr

DrFeelgood 07-25-2007 11:33 AM

Evening! I'm still struggling....:shake:

I've connected the MobilePre USB each and every way I can trying to setup the loop, but can't get a proper trace. Could someone take pity on me and walk me through it? tia!

Kal Rubinson 07-25-2007 12:06 PM

Quote:
Originally Posted by Rayjr View Post

Hello all
I was wondering if TrueRTA can do energy time graphs.

Thanks
RayJr

Not that I've seen. You need different software for that.

Rayjr 08-08-2007 07:09 PM

Quote:
Originally Posted by Kal Rubinson View Post

Not that I've seen. You need different software for that.

Kal
What software do you recommend for doing Energy time graphs......I have been useing a borrowed Sencore sp295..but would like to know what else is out there?

RayJr

Kal Rubinson 08-08-2007 07:13 PM

Room EQ Wizard, ETF, TEF in order of sophistication, complexity and cost. There are others but these are the 3 I know.


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