# HTF can I measure time delay between speakers?



## Ge0 (Jul 23, 2007)

Back when I had my Alpine system I could hit a button on the H700's remote and the system would damn near time align itself. I might have needed to make a tweak here or there but for the most part it was good.

If all else failed, there was always the method of measuring distances to each speaker and adjusting timing that way.

Enter the present....

I am tapping off my factory system to supply my super duper DC REF amps with signal. The DC Refs do not autoset. The problem. The factory system has UNKNOWN TIME ALIGNMENT compensation. The resulting product is all fugged up. Especially since I have moved some drivers from thier stock locations. I can no longer just make distance measurements and plug in the numbers. I need a way to measure the arrival time of each driver and compensate as necessary.

I have a laptop decked out for sound system tuning type stuff but have yet to find a software I can understand that will help out.

I had an idea that I would use my oscilloscope and a impulse function generator in software to set timing. The theory.... Have the scope trigger on the output of the sound card when it generates the impulse function. The second channel of the scope would be tied to the microphone. The second channel to the scope would see a blip when the sound wave arrived at the microphone and excited the microphone element. A small voltage spike would appear. I would then measure the time between the original triggered pulse and the pulse the mic generates to determine transit time of sound waves from one speaker to the next. The end result. I would have a map of the arrival time of each speaker in relation to the other. I could then set time alignment from that.

The hole in my hypothesis. The signal coming from the un-amplified MIC is too weak to detect. The signal I need is lost in noise floor. I do not have access to the AMPLIFIED version of the MIC signal since this is internal to my laptop. I will receive a Behringer Mobilepre in the mail today or tomorrow. However, the same problem occurs here. The raw, un-amplified MIC output enters the preamp but I have no access to the amplified signal. It is processed and converted to digital information within the Mobilepre. I don't want to build a "home brew" analog microphone preamplifier. Especially knowing that some software solution exists out there that can help me.

So, this leads me back to software. Is there a simple to use package available to perform this function? I tried reading through NPANG's tutorial on the subject. However, it is vague as far as ime alignment is concerned and the image links to the posts are broken. I can't see the pictures I would need to make sense of this.

I've been attempting to set timing by ear for a few hours. My attempts are unsuccessful. Admittedly I am no exert in acoustics. I know more about circuits. I've been reading on the subject for two nights and have yet to find a simple answer.

Any help you may offer would be appreciated.

Ge0


----------



## npdang (Jul 29, 2005)

Try this one: http://www.fesb.hr/~mateljan/arta/download.htm


----------



## durwood (Mar 7, 2007)

x2 on arta

after it's installed,

click on the arta.exe

you get this window









then select the "imp" button

press the record (red triangle) and this screen pops up









select the "MLS" tab

click record

(do this for one speaker at a time, mute the ones you are not measuring)

right down the time it of the biggest peak for each speaker, you might need to zoom in/out on the graph, but it usually centers it for you. The delay of the soundcard will also be in there, but it should be the same for all speakers so you can neglect it, no need ot subtract it unless your maximum time delay is limited.

I hope I didn't leave anything out.


----------



## ErinH (Feb 14, 2007)

^

Do you set this up as you would any other RTA, or would you need to input anything into the soundcard?

In other words, I use a laptop, mobile pre-amp USB device, and behringer mic. Is the setup still the same: mobile pre to laptop via usb, and xlr to mic and then record a pink noise track? If so, this should be very easy since I've used smaartlive many times to rta.


----------



## matdotcom2000 (Aug 16, 2005)

bikinpunk said:


> ^
> 
> Do you set this up as you would any other RTA, or would you need to input anything into the soundcard?
> 
> In other words, I use a laptop, mobile pre-amp USB device, and behringer mic. Is the setup still the same: mobile pre to laptop via usb, and xlr to mic and then record a pink noise track? If so, this should be very easy since I've used smaartlive many times to rta.


I think that you would plug into the aux on your headunit to do the measurement


----------



## ErinH (Feb 14, 2007)

My processor has a mini-jack input. 

So, could I do XLR mic from the pre-amp, and stereo-to-stereo headphones from the pre-amp to the processor?

I'm a little confused on this. I've actually been meaning to bring it up in Dang's tutorial but forgot about it.


----------



## durwood (Mar 7, 2007)

matdotcom2000 said:


> I think that you would plug into the aux on your headunit to do the measurement


yep. When you hit record on that program, it generates a short amount of pink noise and plays it out of your soundcard. So you will ened to plug the output of the soundcard into the input of your system. The mic records the burst of pink noise and it loops it back to the program.

You might have to be careful that the soundcard doesn't internally loop the input to output otherwise you will get this looping feedback that is annoying and dangerous. In other words you need to mute the "input" line on the playback panel IIRC.


----------



## chad (Jun 30, 2005)

http://www.eaw.com/products/software/EAWSmaart/

Not ***** stuff, the real deal.


----------



## ErinH (Feb 14, 2007)

durwood said:


> yep. When you hit record on that program, it generates a short amount of pink noise and plays it out of your soundcard. So you will ened to plug the output of the soundcard into the input of your system. The mic records the burst of pink noise and it loops it back to the program.
> 
> You might have to be careful that the soundcard doesn't internally loop the input to output otherwise you will get this looping feedback that is annoying and dangerous. In other words you need to mute the "input" line on the playback panel IIRC.


Okay. So, in my case. 

mobile preamp headphone out--> h701 mic in. Correct? (both mini-jack 3.5mm connectors)


----------



## psycle_1 (Aug 4, 2005)

chad said:


> http://www.eaw.com/products/software/EAWSmaart/
> 
> Not ***** stuff, the real deal.



He's not joking. I'm using it. It is, in fact, the real deal. Uses a bit more processing power on your PC, but well worth it IMO.


----------



## psycle_1 (Aug 4, 2005)

bikinpunk said:


> Okay. So, in my case.
> 
> mobile preamp headphone out--> h701 mic in. Correct? (both mini-jack 3.5mm connectors)


No, preamp out to aux in on your head unit or an open input on your H701.


----------



## chad (Jun 30, 2005)

psycle_1 said:


> He's not joking. I'm using it. It is, in fact, the real deal. Uses a bit more processing power on your PC, but well worth it IMO.


Are you using the newest version? It's reported to be WAY less processor intensive!

I use a REALLY old version, granted it's not as pretty but it gets the job done and was developed when the orig pentium was cutting edge. That allows me to run some other stuff int he background like WMP, or a generation software for signal output. The new stuff is cool but having the old-dirty version is nice on the road when you are using older laptops and need to run smaart, generation software, and the processor software and work fast.


----------



## ErinH (Feb 14, 2007)

psycle_1 said:


> No, preamp out to aux in on your head unit or an open input on your H701.


lol, that seems just like what I said?

the aux out on the h/u goes directly to the processor. The processor has a mic input specifically for auto EQ. 

So, I go preamp out (headphone jack) to mic in on the h701?


----------



## ErinH (Feb 14, 2007)

chad said:


> Are you using the newest version? It's reported to be WAY less processor intensive!
> 
> I use a REALLY old version, granted it's not as pretty but it gets the job done and was developed when the orig pentium was cutting edge. That allows me to run some other stuff int he background like WMP, or a generation software for signal output. The new stuff is cool but having the old-dirty version is nice on the road when you are using older laptops and need to run smaart, generation software, and the processor software and work fast.


Chad, I use that because you said to! But, I only use the RTA portion because I had no idea how to get the time alignment setup. But, thanks to this thread I think I got it figured out. The RTA portion is freaking easy to use and is awesome. My favorite is that you can set the resolution as high as you want and the "delay" for the results can be set so that you have a better idea of what's going on in the system (I learned that from you as well).


----------



## chad (Jun 30, 2005)

bikinpunk said:


> Chad, I use that because you said to! But, I only use the RTA portion because I had no idea how to get the time alignment setup. But, thanks to this thread I think I got it figured out. The RTA portion is freaking easy to use and is awesome. My favorite is that you can set the resolution as high as you want and the "delay" for the results can be set so that you have a better idea of what's going on in the system (I learned that from you as well).


**** you are just feeling it's shoulders! go all the way! Flip to transfer function mode if you are using the In/Out scheme you are supposed to be using and you can RTA with MUSIC! The TF way is also great for setting a "target curve" I rarely use it in standard RTA mode.

The Delay locator is super easy. Put anything into it, hit locate, put the cursor where the waveform begins, wola the distance appears 

I should download a new version and do a screenshot tutorial, it's easy as pie. The trickiest part is getting your levels right and figuring out the I/O scheme. If you have the M-Audio MobilePreUSB then the best way is to make up a cable with a 1/8 female that's mono'd to R and L, then off to 2X1/4 male jacks. 1 1/4" will go into ch2 output the other will go to ch2's input, then turn the monitor function OFF! The 1/8 female will then look like an iPod/whatever. Ch1's XLR input will be the mic input. Now you are set. Then you can say, "if you can plug an iPod into it, I can set it up"

Chad


----------



## ErinH (Feb 14, 2007)

chad said:


> **** you are just feeling it's shoulders! go all the way! Flip to transfer function mode if you are using the In/Out scheme you are supposed to be using and you can RTA with MUSIC! The TF way is also great for setting a "target curve" I rarely use it in standard RTA mode.
> 
> The Delay locator is super easy. Put anything into it, hit locate, put the cursor where the waveform begins, wola the distance appears
> 
> ...



I have no idea what you just said. I read it twice. I suck at this stuff. 

Can you buy the connectors you speak of? I already have one behringer mic & XLR cable, but that's it. And the extent of my knowledge of this stuff is this:
1. My mobile pre has 2 XLR inputs. 1 headphone input (3.5mm jack).
2. My h701 has mic in (3.5mm jack)
3. I can turn on the RTA program
4. I have no idea wtf to do, to do anything you just said

For real, I feel stupid right now.


----------



## Ge0 (Jul 23, 2007)

chad said:


> http://www.eaw.com/products/software/EAWSmaart/
> 
> Not ***** stuff, the real deal.


Damn Chad, you're brutally honest. No beating around the bush to be politically correct for you. I kinda appreciate that.

Ge0


----------



## chad (Jun 30, 2005)

bikinpunk said:


> I have no idea what you just said. I read it twice. I suck at this stuff.
> 
> Can you buy the connectors you speak of? I already have one behringer mic & XLR cable, but that's it. And the extent of my knowledge of this stuff is this:
> 1. My mobile pre has 2 XLR inputs. 1 headphone input (3.5mm jack).
> ...


It also has 2 1/4" ins and outs, one for left I/O One for Right.

You will loop the left out to the left in, turn OFF the monitor function int he M-Audio control panel (basically the cable IS the monitor function for ONE channel) Y'd off of this loop is the output to the audio system.

Smaart uses 2 signals, one original (control) and one input (anaylized) and compares the two, that's the beauty of it and it's purpose.

Channel 1 is the mic input, can't go anywhere else because the loop (monitor) is off.

Now Play something out of your computer using the M-Audio device. Open Smaart, Gain up channel 2 till you see the original waveform (lets say pink noise for now, it should look flattish.) Put mic in car, gain up ch1 till the meters read the same and you don't see peak lights on the M-Audio. Now you see two curves, different colors. Hit the transfer function button, now you see 1 curve, this curve is the DIFFERENCE between the reference and the measured. It is your car's frequency response, if it's glaringly wrong, like no low end then hit the flip channel button 

It's "closed loop measuring" if you may 

Chad


----------



## ErinH (Feb 14, 2007)

Ge0 said:


> Damn Chad, you're brutally honest. No beating around the bush to be politically correct for you. I kinda appreciate that.
> 
> Ge0


Geo, sorry for butting in on your thread man. This just seemed like the best place to ask.


----------



## ErinH (Feb 14, 2007)

chad said:


> It also has 2 1/4" ins and outs, one for left I/O One for Right.
> 
> You will loop the left out to the left in, turn OFF the monitor function int he M-Audio control panel (basically the cable IS the monitor function for ONE channel) Y'd off of this loop is the output to the audio system.
> 
> ...


Okay, I believe I follow.

But I have a few questions:

What is the Monitor you speak of? How do I turn it off?

When I play something out of my computer, do you mean through the computer's speakers (surely not), or what?


----------



## chad (Jun 30, 2005)

The monitor loops the in to the out so you can monitor what's coming into the microphone for studio apps. You only want to "monitor" one channel via the cable.

Open upt he M-Audio control panel, you will see a set of "monitor"sliders hopefully. Turn them down and mute it. I don't have it ont his computer so I'll have to look at home to be sure, but I'm pretty sure it's obvious.

BTW Folks, smaart is fully functional during it's "trial period" 

Chad


----------



## ErinH (Feb 14, 2007)

chad said:


> The monitor loops the in to the out so you can monitor what's coming into the microphone for studio apps. You only want to "monitor" one channel via the cable.
> 
> Open upt he M-Audio control panel, you will see a set of "monitor"sliders hopefully. Turn them down and mute it. I don't have it ont his computer so I'll have to look at home to be sure, but I'm pretty sure it's obvious.
> 
> ...



cool. I appreciate the help.

I probably will figure it all out once I pull it up at home. I'll try to tinker with it this weekend. Make sure you're on the computer Saturday morning, lol.


----------



## chad (Jun 30, 2005)

bikinpunk said:


> cool. I appreciate the help.
> 
> I probably will figure it all out once I pull it up at home. I'll try to tinker with it this weekend. Make sure you're on the computer Saturday morning, lol.


I hope to be laying another coat of fiberglass sat morning


----------



## ErinH (Feb 14, 2007)

chad said:


> I hope to be laying another coat of fiberglass sat morning


False floor?


----------



## chad (Jun 30, 2005)

bikinpunk said:


> False floor?


Tub into spare tire. I need that complete to measure it's volume with media before I can design the wood part of the enclosure. It will be vented so it needs to be tits on


----------



## psycle_1 (Aug 4, 2005)

bikinpunk said:


> lol, that seems just like what I said?
> 
> the aux out on the h/u goes directly to the processor. The processor has a mic input specifically for auto EQ.
> 
> So, I go preamp out (headphone jack) to mic in on the h701?


Umm, no. You will need to play the signal that the PC outputs through the system. Hooking up the output from the soundcard to the mic input on the H701 will not accomplish this.


----------



## durwood (Mar 7, 2007)

psycle_1 said:


> Umm, no. You will need to play the signal that the PC outputs through the system. Hooking up the output from the soundcard to the mic input on the H701 will not accomplish this.


Exactly. Ignore the mic input on you h701. Go right into the analog input on the H701 from your mobile pre. The mobile pre takes the mic signal and pre-amps it to regular line level.

Chad-

That program looks amazing. I guess the trick would be to makes sure you get all your tunning done before the trial runs out $800 is not cheap but it looks freakin awesome.


----------



## ErinH (Feb 14, 2007)

Well, now I'm just confused. How can I tap into the ai-net with a mini-jack cable?


----------



## chad (Jun 30, 2005)

bikinpunk said:


> Well, now I'm just confused. How can I tap into the ai-net with a mini-jack cable?


Does it accept the AInet to RCA adaptor thingy? I just so happen to have one laying around  You just have to be able to tell the receiving device to accept aux from AI net. Sometimes it does, sometimes it does not


----------



## ErinH (Feb 14, 2007)

chad said:


> Does it accept the AInet to RCA adaptor thingy? I just so happen to have one laying around  You just have to be able to tell the receiving device to accept aux from AI net. Sometimes it does, sometimes it does not


I used to have this. Not sure what I did with it. I'll have to hit my parent's house this weekend, but I don't recall seeing it last time I went through my pile. Surely I didn't give it away. *kicks self*


----------



## durwood (Mar 7, 2007)

Why are you confused?

On the mobilepre connect it to you H701 like this. I don't know how to make it any clearer.

Stereo Line out (Mobile pre) stereo minijack 1/8"-> Analog Input RCAs (H701)

buy a minijack to rca cable.


----------



## ErinH (Feb 14, 2007)

I'm an idiot.

You're talking about using the h701's RCA's. I'm sitting here _seeing_ "analog" and _thinking_ ai-net. GOD! 

I have a stereo to rca in my entertainment center for my wife's laptop when we play vids off it. *d'oh!*


What sucks is that I'll have to pull my h/u back out so I can get to the AUX inputs. I knew I should've put some leads on there when I installed it the first time and ran it to my glove box.


----------



## psycle_1 (Aug 4, 2005)

What HU are you using? Why do you need to tap into AI-Net? You can take the output from the PC and connect it to either the Aux In on your HU if you have one (I assume you do) or using one of the analog inputs on the H701. Using the Aux In would probably be the easiest solution IMO. This is how I run my W200/H701 when I need to do impulse responses. I just enable the Aux In on the W200 and select it as my source, connect my soundcard output to it, and connect my mic to the soundcard input.


----------



## durwood (Mar 7, 2007)

LOL. No problem. When you don't the the unit in front of you, it easy to forget what connections you have available.

You shoudl be able to plug directly into the H701 and I thnk select "analog in" on your headunit somewhere, me thinks. I don't own an W200 so I don;t know for sure, but on the controller you could select whatever input you wanted.


----------



## ErinH (Feb 14, 2007)

Well, I know the h/u itself has an aux in (via RCAs) but I'm certain the processor doesn't. 

I suppose I could get an ai-net->RCA but I'm not sure how that would work, really.

I'm just going to have to pull out my h/u and run some leads off the aux in. I should've done that when I installed it, but I was too excited to get it hooked up.


----------



## Ge0 (Jul 23, 2007)

bikinpunk said:


> Well, I know the h/u itself has an aux in (via RCAs) but I'm certain the processor doesn't.
> 
> I suppose I could get an ai-net->RCA but I'm not sure how that would work, really.
> 
> I'm just going to have to pull out my h/u and run some leads off the aux in. I should've done that when I installed it, but I was too excited to get it hooked up.


OK, lets make this clear and concise. THE H701 HAS AN AUXILARY INPUT!!! Plug your ****ing rca's into this and be done with it.

If you are still confused, it is labeled ANALOG 1 on the input section of the H701, right next to the Ai-Net. Inputs. Look on page 38 of your user manual.

Whew... Glad I got that one off my chest. Can we get back on topic now .

Ge0


----------



## chad (Jun 30, 2005)

Ge0 said:


> OK, lets make this clear and concise. THE H701 HAS AN AUXILARY INPUT!!! Plug your ****ing rca's into this and be done with it.
> 
> If you are still confused, it is labeled ANALOG 1 on the input section of the H701, right next to the Ai-Net. Inputs. Look on page 38 of your user manual.
> 
> ...



I ALMOST just blew java thru the nose, almost.... that could have been bad!

Chad


----------



## ErinH (Feb 14, 2007)

Ge0 said:


> OK, lets make this clear and concise. THE H701 HAS AN AUXILARY INPUT!!! Plug your ****ing rca's into this and be done with it.
> 
> If you are still confused, it is labeled ANALOG 1 on the input section of the H701, right next to the Ai-Net. Inputs. Look on page 38 of your user manual.
> 
> ...


Yikes!


----------



## matdotcom2000 (Aug 16, 2005)

psycle_1 said:


> What HU are you using? Why do you need to tap into AI-Net? You can take the output from the PC and connect it to either the Aux In on your HU if you have one (I assume you do) or using one of the analog inputs on the H701. Using the Aux In would probably be the easiest solution IMO. This is how I run my W200/H701 when I need to do impulse responses. I just enable the Aux In on the W200 and select it as my source, connect my soundcard output to it, and connect my mic to the soundcard input.


Can you have multipule aux in that setup???? I am using the aux audio/video in on the actual head unit. So I am wondering can I also us the aux in from the h701???


----------



## Hi There (Mar 16, 2007)

Ge0 said:


> OK, lets make this clear and concise. THE H701 HAS AN AUXILARY INPUT!!!


Do you happen to have an AI Net male-to-female-to-banana plug adapter with and A/D converter on one end and a crossover ethernet cable on the other? I'm having trouble with my speakers. I have a light bulb socket in my glove box I think I can plug in to. Will a doorbell work as a test tone generator?


----------



## chad (Jun 30, 2005)

Hi There said:


> Will a doorbell work as a test tone generator?


If it has a flim-flam inductor you will be fine, if not you will have to shift the phase of the influxor to bring it in to the correct relationship with the Q axis.


----------



## Ge0 (Jul 23, 2007)

chad said:


> I ALMOST just blew java thru the nose, almost.... that could have been bad!
> 
> Chad



Heh heh heh....

I get fiesty once in a while. Just light hearted fun though .

Ge0


----------



## Ge0 (Jul 23, 2007)

bikinpunk said:


> Yikes!


You do know I was just ****in with you right? I meant no offense.

ge0


----------



## ErinH (Feb 14, 2007)

Ge0 said:


> You do know I was just ****in with you right? I meant no offense.
> 
> ge0


Man, it's all good. I would've got pissed too!


----------



## Ge0 (Jul 23, 2007)

bikinpunk said:


> Man, it's all good. I would've got pissed too!



It's hard to judge someones sense of humor over the computer. Rest assured I wasn't being a condescending *******.

Ge0


----------



## psycle_1 (Aug 4, 2005)

matdotcom2000 said:


> Can you have multipule aux in that setup???? I am using the aux audio/video in on the actual head unit. So I am wondering can I also us the aux in from the h701???


Should be able to, but I've never tried it, so I can't tell you for sure.


----------



## Ge0 (Jul 23, 2007)

durwood said:


> x2 on arta
> 
> after it's installed,
> 
> ...


Is this what i should be seeing?









Zoomed in to very start of waveform packet:









Taken from left front midbass driver after ZERO effort to set software up properly.

Ge0


----------



## psycle_1 (Aug 4, 2005)

I'd almost be willing to bet if you hit the "Get" button where it says "Delay for phase estimation" it will tell you the exact ms delay without having to zoom in and look at the peak.


----------



## chad (Jun 30, 2005)

Ge0 said:


> Is this what i should be seeing?
> 
> 
> 
> ...


Looks right to me  But I'm not "one" with that software


----------



## ErinH (Feb 14, 2007)

Geo, try not to kill me.

When you did that test, did you take a headphone out, to rca in on the midbass rca? 


*hides for fear of looking like a complete dumbass who doesn't comprehend what you guys are telling me*


----------



## Ge0 (Jul 23, 2007)

bikinpunk said:


> Geo, try not to kill me.
> 
> When you did that test, did you take a headphone out, to rca in on the midbass rca?
> 
> ...


Go **** yourself....

Kidding 

I don't have auxilary RCA inputs to my amps or head unit. The amps are balanced beasties with proprietary cabling. The head unit is stock.

Rather, I tapped into the AUX input of my factory equipt rear seat DVD player. This posses one pain in the ass after another but does allow me to get the job done.

Ge0


----------



## DonutHands (Jan 27, 2006)

on the topic of measurements, if its ok, i have a question. when taking meausrements you will be measuring the left and right channels separatly for FR. so what happens with mono subwoofers where the signal is summed. or when you have stereo in bridged to mono out?


----------



## Ge0 (Jul 23, 2007)

internecine said:


> on the topic of measurements, if its ok, i have a question. when taking meausrements you will be measuring the left and right channels separatly for FR. so what happens with mono subwoofers where the signal is summed. or when you have stereo in bridged to mono out?


I process each amplifier channel seperately. Each speaker in my system has its own dedicated amp with its own dedicated crossover/EQ. I don't have this problem. I have bigger problems trying to keep track of this all .

However, if you are processing a stereo pair, then splitting this to all amps, you have work on your hands. Any tweak you make to the full range signal will affect your subwoofers response summed or not.

Ge0


----------



## npdang (Jul 29, 2005)

Looks good, although that's one god aweful looking IR.


----------



## Ge0 (Jul 23, 2007)

npdang said:


> Looks good, although that's one god aweful looking IR.


Quit busting my balls .

This was quick and dirty. Software has not been calibrated for my laptop yet. Also measurement taken while engine was running, heater and fan blowing hard, and i was sitting in the drivers seat with a microphone clipped to the right side (drivers side) temple of my eyeglasses. I'm sure it would look better if I wanted to do this right.

Question. The test signbal ARTA played sounded a lot like a 10 second burst of pink noise. Even though it was the MLS packet. Are these supposed to sound similar?

I always thought the way to determine propigation delay was to send an impulse function (a short blip) through your system and look for the arrival time of that function at your microphone. This is how I've heard it done in the past.

Still need to do some reading to figure out exactly what to do with the impulse response. Perhaps another thread...

Ge0


----------



## chad (Jun 30, 2005)

Ge0 said:


> and I was sitting in the drivers seat with a microphone clipped to the right side (drivers side) temple of my eyeglasses.


You don't have to tell the WHOLE story, some of us got a bad visual there   

How was the reflection off the pocket protector? Could that have played a role?


----------



## psycle_1 (Aug 4, 2005)

Ge0 said:


> Quit busting my balls .
> Question. The test signbal ARTA played sounded a lot like a 10 second burst of pink noise. Even though it was the MLS packet. Are these supposed to sound similar?


Yes, they can sound similar. Sounds like you did everything right.


----------



## durwood (Mar 7, 2007)

The thing I found with arta, and this might be completely dependent on the soundcard/setup, I had to loop the output back to the input on one channel so that it had a reference. If I didn't do that, it didn't seem to be showing a correct time difference between channels.

So what you might want to do is try taking the input on the line in on soundcard and split the channels. I.E. on the left input plug your left line out into the left line in. Then in ARTA in the MLS screen, tell it to measure the mic on the channel 2(right channel?) and use channel 1 (left?) as the reference. Then you will see the blip from the reference and you can mark it as your zero point, and then you will se your speaker impulse later.

^That's pretty much what I had to do if it makes any sense.

Another good note, after you do the imp measurement, you can click the smoothed FR button and it will give you your frequency repsonse. You can then click the overlay button to save it and continue measuring and overlay ALL your responses. 

I usually just do it fo the whole left and right side when finished. I also liek the measure the FR differently than the time measurements. For the time measurements, I center the mic and face it forward. For L/R FR measurements, I like to turn the mic to each side with my fake person setup.


----------



## psycle_1 (Aug 4, 2005)

Looping one of the outputs into an input also allows the program to correct for latency issues from the soundcard.


----------



## Ge0 (Jul 23, 2007)

durwood said:


> I usually just do it fo the whole left and right side when finished. I also liek the measure the FR differently than the time measurements. For the time measurements, I center the mic and face it forward. For L/R FR measurements, I like to turn the mic to each side with my fake person setup.


What you said about looping back a channel makes sense. Up until you explained this I did not understand why others were doing it.

Now, about your fake person setup... 

I had an epiphany regarding the same subject a while ago. One Wednesday night I would get real drunk, I mean **** faced and slobbering drunk. I would then venture over to my local Sears store on my bike (couldn't drive a car that intoxicated, it's illegal) and storm the doors. My goal would be to search out and grab one of their life sized mannequin's from the women's lingerie department. It doesn't matter what she looks like for this endevour, as long as she is scantly clad and has a smile on her face. I would need to move quick to avoid detection and my utter demise. On my way out the door I would grab some Kerosine and a family sized package of Skittles, oh I like Skittles (www.Skittles.com). Come to think about it, I'm not sure if Sears even sells Skittles. It's a brilliant, and tasty idea, but I don't want to spend too much time searching for them with a stolen mannequin and jug of kerosine under my arm. Finally, I would get back to my bike and make a run for it. My bike is the offroad type with shocks front and rear. I could stay off the main thoroughfares and remain undtected until I made it to the safety of my Mom's garage. 

The next day would be a blur, but at least I would have the mannequin I need to run my experiment. You see, I have two of these microphones http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=240-520
I would drill holes in the head of the mannequin where the ear canals should be and mount the microphones inside. If I wanted to get real tricky I would fashion an ear cannal about 3/4" long and recess it into the mannequin's head. The mics would be mounted at the end of the simulated ear canals. Wouldn't placing a human model in your seat be a better approximation of your vehicles frequency response as you hear it vs. a mic sitting in the center of your seat? The reflections and absorbtions off your body and such would be taken into acocunt.

Never mind my planned means of procuring the mannequin, that is silly. Is my theory once I have secured one and modified it sound?

Ge0


----------



## Ge0 (Jul 23, 2007)

durwood said:


> The thing I found with arta, and this might be completely dependent on the soundcard/setup, I had to loop the output back to the input on one channel so that it had a reference. If I didn't do that, it didn't seem to be showing a correct time difference between channels.
> 
> So what you might want to do is try taking the input on the line in on soundcard and split the channels. I.E. on the left input plug your left line out into the left line in. Then in ARTA in the MLS screen, tell it to measure the mic on the channel 2(right channel?) and use channel 1 (left?) as the reference. Then you will see the blip from the reference and you can mark it as your zero point, and then you will se your speaker impulse later.
> 
> ^That's pretty much what I had to do if it makes any sense.


As of right now I'm using the microphone preamp built into my laptop and a cheap $20 Panasonic capsule microphone. I have a Behringer Mobilepre USB sound card and ECM8000 mic coming in the mail today. I'm not familiar with this gear yet but will attempt such a setup with it once I have grasped what I have on my hands.

Thanks,

Ge0


----------



## chad (Jun 30, 2005)

Ge0 said:


> I had an epiphany regarding the same subject a while ago. One Wednesday night I would get real drunk, I mean **** faced and slobbering drunk. I would then venture over to my local Sears store on my bike (couldn't drive a car that intoxicated, it's illegal) and storm the doors. My goal would be to search out and grab one of their life sized mannequin's from the women's lingerie department. It doesn't matter what she looks like for this endevour, as long as she is scantly clad and has a smile on her face. I would need to move quick to avoid detection and my utter demise. On my way out the door I would grab some Kerosine and a family sized package of Skittles, oh I like Skittles (www.Skittles.com). Come to think about it, I'm not sure if Sears even sells Skittles. It's a brilliant, and tasty idea, but I don't want to spend too much time searching for them with a stolen mannequin and jug of kerosine under my arm. Finally, I would get back to my bike and make a run for it. My bike is the offroad type with shocks front and rear. I could stay off the main thoroughfares and remain undtected until I made it to the safety of my Mom's garage.
> 
> 
> Ge0


We are not allowed to drink together  Ever 

The human body in my experience is does not have much different properties than a car seat. In fact in one concert hall here the seats are designed to mock the fact that a full house would have the same absorption properties if the room were full or empty. (they have cushions, ooohhhhhh) They forgot to figure in ambient noise of 1000 live people breathing  

I'm lucky enough to have racing _Style_ seats with a hole in the head rest. I have a convoluted hanging system to hang the mic there and de-couple it. Seems to work well and gets about the same results as if I have it placed on my head, except it's coupled MORE if it's on my body.... Go figure.

Remember the mic is onmi, placing it near your body greatly changes it's pattern and frequency response. It WANTS to run free Field 


Chad


----------



## Ge0 (Jul 23, 2007)

chad said:


> We are not allowed to drink together  Ever


Chad, I was expecting more of a creative response from you regarding my plot to get the mannequin . The scarey part, this idea came from an experience I had as a young and dumb teenager experimenting with the uses of medicinal marijuana and beer. 

Thanks for the brief explaination of mic physics. Up until now I thought it would be best to keep this little mic close to my ear while tuning to more accurately approximate what I would actually hear. Sounds like that theory is ****.

Now I'm stuck sitting outside my vehicle in the cold while I tune using a mic sitting in my warm drivers seat. Crap....

Ge0


----------



## durwood (Mar 7, 2007)

haha, really my "fake person" setup is really just a cheesy way of putting the mic where my head would be and where my ears would be. I'd never go as far as robbing a sears for a manequin but the picture of someoen riding a bike with a manequin-I think you watched "Manequin" a few too many times while high. If you really want to try a manequin, they have upper torso with heads on ebay. I would be worried that the hard surface would cause reflections and mis-readings. The foam nerf ball was the closest thing I could think of that would absorb rather than create more resonances.

I measured how far from the headrest my head/ear was, then how far down from the ceiling. Then I use the nerf ball to essentially decouple it from the stand I made from the box and PVC pipe and it also acts as a head. I posted pics of this cheesey setup in your other thread about mic stands.

Does it work? For the most part. I think pointing the mic L/R works fairly good too for measuring FR, better than pointing straight forward. In my car if I point the omni-directional mic staright forward I get a deep null at ~1Khz down maybe 15db. I can tell you though with my ears I have no problem with 1Khz so I didn't trust that setup.


----------



## chad (Jun 30, 2005)

Ge0 said:


> Chad, I was expecting more of a creative response from you regarding my plot to get the mannequin . The scarey part, this idea came from an experience I had as a young and dumb teenager experimenting with the "medicinal" uses of marijuana and beer.
> 
> 
> Ge0


^Corrected......^

We tried to steal one a limb at a time, had a head and some arms :blush: 

In fact the head was my headphone holder till just a few years ago. Complete with Curtney Love style make-up (applied hammered of-course, had to duplicate actual "operating" conditions). A fullet wig, and a Marlboro. I even took the little whore out on the road with me, got many-o-laugh!

Her name was "Little Whore"

I preferred to re-dress and contort them, less legalities involved and when done correctly can warp a young child for LIFE! I can still hear the screams..... Good times!


No garage eh? Living up north? Ouch.....


----------



## chad (Jun 30, 2005)

durwood said:


> I measured how far from the headrest my head/ear was, then how far down from the ceiling. Then I use the nerf ball to essentially decouple it from the stand I made from the box and PVC pipe and it also acts as a head. I posted pics of this cheesey setup in your other thread about mic stands.
> 
> Does it work? For the most part. I think pointing the mic L/R works fairly good too for measuring FR, better than pointing straight forward. In my car if I point the omni-directional mic staright forward I get a deep null at ~1Khz down maybe 15db. I can tell you though with my ears I have no problem with 1Khz so I didn't trust that setup.


My neighbors shake their heads when they see me with blue tape and a microphone standing outside the car with a remote. If they saw nerf balls and PVC going in I think they would shoot me to put me out of my misery 


I DID recently buy a tripod stand though to play with........

Chad


----------



## durwood (Mar 7, 2007)

Me picturing Geo...










"Some guys have all the luck"

Chad man, I'd hate to see what goes on at a bonfire with you around.


----------



## chad (Jun 30, 2005)

durwood said:


> Chad man, I'd hate to see what goes on at a bonfire with you around.


Oh, it's stupid..... Since I practice every weekend it's above freezing


----------



## Ge0 (Jul 23, 2007)

durwood said:


> Me picturing Geo...
> 
> 
> 
> ...


Close, but a shiney Schwinn 10 speed, not a motor cycle. 

Ge0


----------



## DonutHands (Jan 27, 2006)

Ge0 said:


> I process each amplifier channel seperately. Each speaker in my system has its own dedicated amp with its own dedicated crossover/EQ. I don't have this problem. I have bigger problems trying to keep track of this all .
> 
> However, if you are processing a stereo pair, then splitting this to all amps, you have work on your hands. Any tweak you make to the full range signal will affect your subwoofers response summed or not.
> 
> Ge0


lucky you. but i still dont know how to measure the sub.


----------



## durwood (Mar 7, 2007)

internecine said:


> lucky you. but i still dont know how to measure the sub.


My sub is mono. I leave it turned on when measuring each side's FR. It's a compromise when tuning the low end between the left and right midbass because it might interact slightly different between each side, but it's not incredibly bad.


----------



## Ge0 (Jul 23, 2007)

internecine said:


> Earlier: on the topic of measurements, if its ok, i have a question. when taking meausrements you will be measuring the left and right channels separatly for FR. so what happens with mono subwoofers where the signal is summed. or when you have stereo in bridged to mono out?
> 
> Recent: lucky you. but i still dont know how to measure the sub.


Don't get me wrong guy. Not trying to blow you off or tell you my setup doesn't encounter this problem because it is magically somehow better.

It is my understanding that sub bass frequencies are mixed mono in the studio on stereo tracks. Meaning, anything below your crossover point will be the same information on both channels.

So, panning left vs. right while tuning the entire system should not affect your subs frequency response. This is whether you sum channels or use a bridged channel pair.

Did that help?

Anyone care to correct me?

Ge0


----------



## durwood (Mar 7, 2007)

I don't know much about the recording end of it, but I do know that there have been studies done that show people cannot determine the direction of subbass, but it can range from 80-120Hz for the cuttoff point at which it is difficult or near impossible to locate neglecting outside influences such as panels rattling, air movement and such.

Just remember when your sub is mono, you will need it to be part of frequency response for each side.


----------



## Luke352 (Jul 24, 2006)

Ok so I've been playing around with the ARTA program, and I did the whole mute all channels except for one (my LH midrange), now I hit record in the MLS function and I get a big peak at 6.250, now I mute that channel and turm up the one on the other side (midrange) and do it again yet I get another 6.250 delay hmm WTF, the mic is positioned correctly, so I do it all again and get the same result, no matter what I do I get the peak at 6.250. So I fiddle with volume and managed to smooth it out till I have the 6.250 peak and then another smaller one around the 10ms point, so I do LH and RH midrange and it shows roughly a 1 ms difference (one around 10ms the other around 11ms), which seems about right. So onto the midbass and all I can get is the peak at 6.250 nothing I do gets rid of it, and I can't find another smaller peak like I had with the midrange.

HELP guys what the hell am I doing wrong, or what have I missed in the setup. I'm just using the demo is it something to do with that?

Here is just a quick measurement I did just using my laptop's built in speaker and mic, so just a measurement of the laptop, shows the peak I'm talking about.


----------



## Ge0 (Jul 23, 2007)

Luke352 said:


> Ok so I've been playing around with the ARTA program, and I did the whole mute all channels except for one (my LH midrange), now I hit record in the MLS function and I get a big peak at 6.250, now I mute that channel and turm up the one on the other side (midrange) and do it again yet I get another 6.250 delay hmm WTF, the mic is positioned correctly, so I do it all again and get the same result, no matter what I do I get the peak at 6.250. So I fiddle with volume and managed to smooth it out till I have the 6.250 peak and then another smaller one around the 10ms point, so I do LH and RH midrange and it shows roughly a 1 ms difference (one around 10ms the other around 11ms), which seems about right. So onto the midbass and all I can get is the peak at 6.250 nothing I do gets rid of it, and I can't find another smaller peak like I had with the midrange.
> 
> HELP guys what the hell am I doing wrong, or what have I missed in the setup. I'm just using the demo is it something to do with that?


You ran into the same thing I did today . You're going to need to set a reference by feeding one channel back into itself as Durwood mentioned earlier. I'll be experimenting with that tomorrow.

Ge0


----------



## npdang (Jul 29, 2005)

You can use any variety of stimulus to record the impulse response. I believe ARTA uses MLS, which is something like psuedorandom white noise.

You don't have to do any further post processing of the impulse response once you have it. Just look at the initial arrival time of each driver, and then align them all. The ****ty thing is the initial spike in a car isn't always the one that's highest in amplitude, as evidenced by your own measurment... and if you compare the response to an ideal or even that of a home setup it's really aweful looking. If you want the frequency response, it's just the Fourier transform of the impulse response.


----------



## npdang (Jul 29, 2005)

For mono signals like the sub, you treat it as one speaker. Not sure I get the question. Even if it's a summed signal, you only care about the end result of how long it took to reach the mic.

My guess for why you are getting the same time measurement .... you either have some setting on to normalize the initial arrival time... or your soundcard is recording at random intervals throwing off the time measurement... so the software automatically normalizes it to a given time. For example... you take one measurement and the soundcard delay is 5ms, but on the second measurement the delay is suddenly 10ms, and on another measurement you get a delay of 2ms. Some cards like the MAudio transit have a fixed delay with each measurement, so this isn't a problem. As Geo mentioned though, by running a loopback cable on one channel the software can calculate the soundcard delay on each measurement and correct for it.


----------



## Ge0 (Jul 23, 2007)

npdang said:


> You can use any variety of stimulus to record the impulse response. I believe ARTA uses MLS, which is something like psuedorandom white noise.
> 
> You don't have to do any further post processing of the impulse response once you have it. Just look at the initial arrival time of each driver, and then align them all. The ****ty thing is the initial spike in a car isn't always the one that's highest in amplitude, as evidenced by your own measurment... and if you compare the response to an ideal or even that of a home setup it's really aweful looking. If you want the frequency response, it's just the Fourier transform of the impulse response.


I have a quick question for you, or anyone else reading this thread that might use a Mobilpre. Well, I want to feed a channel back to its corresponding output to set a reference for time measurements in ARTA. However, I'm confused about how to do this with the Mobilepre. How do channels 1&2 on the Mobilepre correspond to left and right mic inputs within windows applications? Say I wanted to use the left channel for the mic and right channel for the feedback reference. How would I do this?

Ge0


----------



## Ge0 (Jul 23, 2007)

Ge0 said:


> I have a quick question for you, or anyone else reading this thread that might use a Mobilpre. Well, I want to feed a channel back to its corresponding output to set a reference for time measurements in ARTA. However, I'm confused about how to do this with the Mobilepre. How do channels 1&2 on the Mobilepre correspond to left and right mic inputs within windows applications? Say I wanted to use the left channel for the mic and right channel for the feedback reference. How would I do this?
> 
> Ge0


I may have answered my own question through experimentation. It appears channel one on this sucker is tied to logical channel left. Channel 2 is tied to logical channel right.

I believe I should plug the MIC into channel 1 and select it as the input channel in ARTA. I should then jumper channel 2 input to output on the Mobilepre and select it as the reference in ARTA. I should be set as long as the software takes care of the math.

Ge0


----------



## chad (Jun 30, 2005)

Ge0 said:


> I may have answered my own question through experimentation. It appears channel one on this sucker is tied to logical channel left. Channel 2 is tied to logical channel right.
> 
> I believe I should plug the MIC into channel 1 and select it as the input channel in ARTA. I should then jumper channel 2 input to output on the Mobilepre and select it as the reference in ARTA. I should be set as long as the software takes care of the math.
> 
> Ge0


That is correct........

I built a cable that has a 1/4" male then to another 1/4" male, then to a 1/8" stereo female mono'd out. All in parallel. Now I can do my "jump" and send to the system" U sued 1/8" stereo because it seems every rig I deal with now has the abiility to plug into an MP3 player with ease. If you can plug it into an MP3 player I can get my measurement rig into it.

Turn off the monitor function in the M-Audio software


----------



## Ge0 (Jul 23, 2007)

chad said:


> That is correct........
> 
> I built a cable that has a 1/4" male then to another 1/4" male, then to a 1/8" stereo female mono'd out. All in parallel. Now I can do my "jump" and send to the system" U sued 1/8" stereo because it seems every rig I deal with now has the abiility to plug into an MP3 player with ease. If you can plug it into an MP3 player I can get my measurement rig into it.
> 
> Turn off the monitor function in the M-Audio software


I am still at a loss as to why you split off an 1/8" mini-jack stereo connector from your 1/4" channel 2 jumper plug. I thought this jumper was used just to set a reference by feeding signal output on channel 2 to channel 2's microphone input. You mention plugging channel 2 feedback into an MP3 player? Why? The MP3 player only provides another output and is another signal source? Call me thick skulled I don't care. Just having a tough time picturing this.

I intend on using the 1/8" stereo output from the Mobilepre to feed test signal to my system using an 1/8" mini-jack to RCA converter cable. is there something wrong with this philosophy?

Ge0


----------



## chad (Jun 30, 2005)

Ge0 said:


> I intend on using the 1/8" stereo output from the Mobilepre to feed test signal to my system using an 1/8" mini-jack to RCA converter cable. is there something wrong with this philosophy?
> 
> Ge0


Only once channel of that RCA will have ref signal, if the monitor is not off the other will have microphone loop-thru..... You will hurt yourself and your speakers with feedback if you dump the mic signal into your rig


----------



## Ge0 (Jul 23, 2007)

chad said:


> Only once channel of that RCA will have ref signal, if the monitor is not off the other will have microphone loop-thru..... You will hurt yourself and your speakers with feedback if you dump the mic signal into your rig


Damn Chad, thanks for all the help AND the for pretty pictures.

I understand what you were doing with the 1/8" jack now. You confused the **** out of me when you said you could connect an iPod to it. I don't have a 1/8" minijack input to my system.

I could accomplish the same task using the stereo output from the Mobilepre to rca converter. This would only give me ONE live channel. However, I have a RCA splitter to feed my system left and right from a single RCA jack. 

Also, in the Mobilepre control panel I have three options. Recording Gain, Direct Monitor, and Output Gain. I assume when you say to turn off the monitor that I should mute DIRECT MONITOR?

I found this out the hard way last night ****ing around with this system on my home computer tie to a high powered 5.1 channel surround system.

Ge0


----------



## durwood (Mar 7, 2007)

Ge0 said:


> I found this out the hard way last night ****ing around with this system on my home computer tie to a high powered 5.1 channel surround system.
> 
> Ge0


 Did you kill anything? I thought I killed one of my LPG tweeters but I took it apart, put it back together and wala! Working again. Stupid Creative Audigy crappy loopback problem in the drivers.


----------



## durwood (Mar 7, 2007)

Note to anyone using a creative audigy soundcard and an extrenal micpreamp:

First use the default drivers on the installation disc, the newest drivers on their website completely changed this and I have no idea if it can be defeated.



> The default setting of the Audigy mixer has the Line-In signal playing back through the Line-Out. This places the system in a hard wired feedback loop when you patch the Line-Out to the Line-In for testing purposes. Depending on the level settings, the system may oscillate of just give a bogus frequency response.
> 
> Fortunately the fix is quite simple. You just need to set the mixer so it does not route the Line-In signal to the Line-Out. The details are included in the Audigy setup file below:
> 
> http://www.trueaudio.com/downloads/audigy-setup.pdf


----------



## Ge0 (Jul 23, 2007)

durwood said:


> Did you kill anything? I thought I killed one of my LPG tweeters but I took it apart, put it back together and wala! Working again. Stupid Creative Audigy crappy loopback problem in the drivers.


Nope, did not blow anything. Besides my ears that is.

Ge0


----------



## chad (Jun 30, 2005)

Ge0 said:


> Damn Chad, thanks for all the help AND the for pretty pictures.


No problem, Bikinipunk and I were shooting PM's last night and he sent me that pic, I told him I'd exercise my less than fab Gimp skillz to help him out.



Ge0 said:


> I understand what you were doing with the 1/8" jack now. You confused the **** out of me when you said you could connect an iPod to it. I don't have a 1/8" minijack input to my system.


Sorry. I meant, if you can connect an iPod to the sound system, you can connect your analysis rig. There's ALWAYS a 1/8" mini to RCA floating around somewhere and nearly every rig I work with live uses an MP3 player as break, in, and out music.... except mine which has a Behringer U-Control built into the effects rack and the laptop... because that's how I roll 



Ge0 said:


> I could accomplish the same task using the stereo output from the Mobilepre to rca converter. This would only give me ONE live channel. However, I have a RCA splitter to feed my system left and right from a single RCA jack.


That SHOULD work. I opted out of that because I had the **** on hand to build the splitter and I know that the headphone out probably goes thru a headphone buffer amp. I have no idea if there's any phase shift there, frequency irregularities, or difference between the line out. Therefore my thinking was that a hard-wire from the line out is the only way to assure that the computer and sound system is seeing the exact same reference signal.



Ge0 said:


> Also, in the Mobilepre control panel I have three options. Recording Gain, Direct Monitor, and Output Gain. I assume when you say to turn off the monitor that I should mute DIRECT MONITOR?


Yep, direct monitor.



Ge0 said:


> I found this out the hard way last night ****ing around with this system on my home computer tie to a high powered 5.1 channel surround system.
> 
> Ge0


Do you now have the dreaded "will somebody please answer that phone already" effect going on?


----------



## Ge0 (Jul 23, 2007)

chad said:


> Do you now have the dreaded "will somebody please answer that phone already" effect going on?


Yes, unfortunately it has been going on for a few years! I am taming down the "BOOM" factor of my new system in an attempt to preserve what hearing I have left. Just want smooth and realistic sound.

Ge0


----------



## chad (Jun 30, 2005)

More on direct monitor:

Direct Monitor
This section controls the level of the hardware direct monitor. The
MobilePre USB provides an analog monitor path from the inputs to the
outputs.When signal is recorded into software, there is often a slight delay
before it reaches the outputs. This delay, called latency, is caused by the
processing required to convert and record audio.Any delay can distract the
artist being recorded, so the MobilePre USB provides this “Direct
Monitor” for use during recording.
Volume: These faders control the level of the direct monitor path. Set
the controls to find the right balance while recording.
Mute: This box, when checked, stops the direct monitor signal from
reaching the recording software.
21
Link: This button links channels 1 and 2, so that any changes made to one
slider will change the other.
Left Only: This box, when checked, sends only the left (Channel 1) input
to the direct monitor.This signal will be sent to both outputs.
See the “Using the MobilePre USB” section in this manual for more
information about using direct monitor.

From: http://www.m-audio.com/images/global/manuals/060628_MPre_UG_EN01.pdf

Chad


----------



## Ge0 (Jul 23, 2007)

Well, I got the whole rig up and running. I believe I dialed in time alignment pretty good. Worse case on one driver was 2.7ms (I have a big and long vehicle using rear fill). This **** is accurate! 

It was encouraging to note that I was only a few 10ths of a millisecond off on one driver and only one 10th off on the other setting this by ear. I didn't attempt tweets until I had the rig going. I can't judge high frequencies that good. I'll spend the next week or so fine tuning this by ear to see if I can perfect it in my mind at least. 

On another note. it is interesting to see how time alignment affected my frequency response. A few dips I could not cure before came back into line. I guess correcting time delays minimized combo filtering?

I guess the next step would be tweaking the frequency response of each driver individually. This may help with image smearing at certain frequencies. But, maybe this is for another topic?

Ge0


----------



## DonutHands (Jan 27, 2006)

So chad, you ever get around to writing up a tutorial for smaart?

ive got the thing, and ive taken a look at the program but i cant figure out which of the modes is going to let me take a MLS measurement.


----------



## chad (Jun 30, 2005)

internecine said:


> So chad, you ever get around to writing up a tutorial for smaart?
> 
> ive got the thing, and ive taken a look at the program but i cant figure out which of the modes is going to let me take a MLS measurement.


Naa Yet, I may over break if I get my projects finished.


----------



## Ge0 (Jul 23, 2007)

Big question.

Its relatively easy to align higher frequency drivers. You can pretty much tell where the first peak in the impulse packet begins.

BUT, say you wanted to align your front stage with a sub in the rear (uhhh, not in my rear, my vehicles rear). It is hard to target where the first peak is in the impulse packet since everything is sooo stretched out.

Should I just do this based on distance and call it a day?

Ge0


----------



## chad (Jun 30, 2005)

Yeah, That's what I do for the most part and re-check it with the PC. Sometimes I [gasp] make my sub arrive sooner than the front stage by just a tiny bit. Seems to help pull if forward.


----------



## DonutHands (Jan 27, 2006)

well in that case, can you or bikinpunk tell me where the MLS measurement is?
not interested in time arrival stuff just yet as i dont have any TA abilities in my proc.

Thanks guys


----------



## durwood (Mar 7, 2007)

I don't know if SMAART actually does MLS, but rather instead it uses the pink noise generator in conjuction with your loopback cable to measure impulse or time delay. Without having the program infront of me or not knwoing what version you have, but I think it's got a button called "impulse".


----------



## DonutHands (Jan 27, 2006)

ouch, ok it looks like you need an additional program called accoustictools to get MLS measurement capability.


----------



## durwood (Mar 7, 2007)

internecine said:


> ouch, ok it looks like you need an additional program called accoustictools to get MLS measurement capability.


were you going to use the MLS for determining time delay or for something else?


----------



## DonutHands (Jan 27, 2006)

just frequency response, no time delay. wanted to use mls to meaure Fr to reduce measuring relfections.


----------



## Ge0 (Jul 23, 2007)

internecine said:


> just frequency response, no time delay. wanted to use mls to meaure Fr to reduce measuring relfections.


Goolge the term "ARTA". Damn nice program. Free unless you feel real guilty and want to buy it. 

Ge0


----------



## backwoods (Feb 22, 2006)

chad said:


> ^Corrected......^
> 
> Complete with Curtney Love style make-up (applied hammered of-course, had to duplicate actual "operating" conditions). A fullet wig, and a Marlboro. I even took the little whore out on the road with me, got many-o-laugh!


 
each time I see this thread, this part confuses me

So, I am to assume as part of your normal daily routine, you wear makeup courtney love style?


----------



## DonutHands (Jan 27, 2006)

i played with it a bit, and i guess i will be going back to it. it has a REALLY clunky interface with the stimulus button being in a different window and all. and the overly setup is going to take some getting used to.

i wanted somthing nicer, and i thought smaart was the way to go, but it dosent look like it at this point unless im missing the MLS portion of the program.


----------



## chad (Jun 30, 2005)

backwoods said:


> each time I see this thread, this part confuses me
> 
> So, I am to assume as part of your normal daily routine, you wear makeup courtney love style?


My mannequin head did that I used as a headphone holder


----------



## backwoods (Feb 22, 2006)

I get that, but you said the head was to imitate your daily routine. The cig makes sense, maybe even the wig..

it's the makeup that gives me the old wet finger in the ear feeling...


----------



## Ge0 (Jul 23, 2007)

backwoods said:


> each time I see this thread, this part confuses me
> 
> So, I am to assume as part of your normal daily routine, you wear makeup courtney love style?


He was just commenting on my ephiphany:



Ge0 said:


> Now, about your fake person setup...
> 
> I had an epiphany regarding the same subject a while ago. One Wednesday night I would get real drunk, I mean **** faced and slobbering drunk. I would then venture over to my local Sears store on my bike (couldn't drive a car that intoxicated, it's illegal) and storm the doors. My goal would be to search out and grab one of their life sized mannequin's from the women's lingerie department. It doesn't matter what she looks like for this endevour, as long as she is scantly clad and has a smile on her face. I would need to move quick to avoid detection and my utter demise. On my way out the door I would grab some Kerosine and a family sized package of Skittles, oh I like Skittles (www.Skittles.com). Come to think about it, I'm not sure if Sears even sells Skittles. It's a brilliant, and tasty idea, but I don't want to spend too much time searching for them with a stolen mannequin and jug of kerosine under my arm. Finally, I would get back to my bike and make a run for it. My bike is the offroad type with shocks front and rear. I could stay off the main thoroughfares and remain undtected until I made it to the safety of my Mom's garage.


Ge0


----------



## chad (Jun 30, 2005)

backwoods said:


> I get that, but you said the head was to imitate your daily routine. The cig makes sense, maybe even the wig..
> 
> it's the makeup that gives me the old wet finger in the ear feeling...


It _was_ in my daily routine, her head was always parked on my drive rack and my headphones parked on her. I ALWAYS have toys at work, especially on the road, it's fun. You go to different places with different local crews and they would add to the collection. A female stage hand would always take pride in "touching up" her makeup Most popular was the ever evolving "crash scene" on the doghouse of the console that included wax pencil skid marks, banged up matchbox cars, even a propane powered flaming tanker truck. Another classic was a Britney Spears Barbie that pole danced on a littlelite (a goose neck lamp) She had various neo magnets drilled into her and the joints heated and loosened. Then I would apply the direct out of the kick channel to an amplifier driving an electro magnet hidden underneath her, farking classic! Little did I know how true it would become. Things like this keep sick bastards like me from getting home-sick, whatever works.



Ge0 said:


> He was just commenting on my ephiphany:


Which gets funnier every time I read it!


----------



## ErinH (Feb 14, 2007)

chad said:


> Only once channel of that RCA will have ref signal, if the monitor is not off the other will have microphone loop-thru..... You will hurt yourself and your speakers with feedback if you dump the mic signal into your rig


Chad, I noticed something today and I might just need to speak with you over the phone about it as it just doesn't make sense...

I was calibrating TrueRTA today. They say to connect line out to line in. So I did per the picture above. I set trueRTA to "R" for right and got a nasty calibration line. I tinkered around and no matter what settings I used it just wouldn't come out to a flat line. I even switched the display results to "L+R" and still had nasty results. Then I connected the 1/L Output to the 2/R input and let it calibrate... perfectly flat line. Left it on "L+R". 


I don't understand this. For ****s and grins I disconnected the input cable and let it calibrate. Got a bad calibration again. So, the 'wrong' connection (no looped connection at all) gives me bad results and connecting the Channel 2 output to Channel 2 input gives me bad data. That leads me to believe that connecting channel 2 to itself is wrong. 

Any idea of what's going on? Is what seems to be the right way, actually wrong?


----------



## BMWturbo (Apr 11, 2008)

I have mine connected as above, BUT I'm using the stereo line out Left channel to feed in to dual RCA's. The Right stereo line out is not connected.

I then made a tiny 1/4" M-M mono lead that runs between the Ch 2 Out and Ch 2 In.

Maybe you have used a stereo 1/4" M-M? which might be doing something to the in/outs.


----------



## chad (Jun 30, 2005)

BMWturbo said:


> I have mine connected as above, BUT I'm using the stereo line out Left channel to feed in to dual RCA's. The Right stereo line out is not connected.
> 
> I then made a tiny 1/4" M-M mono lead that runs between the Ch 2 Out and Ch 2 In.
> 
> ...



You really don't know what's between the two outputs in the way of buffer/etc. I feel safer running the same darn thing into the input of the reference as I do the test "subject."

bikini, I don't know, I'll have to look into it, I'm in really no position to think right now


----------



## BMWturbo (Apr 11, 2008)

chad said:


> You really don't know what's between the two outputs in the way of buffer/etc. I feel safer running the same darn thing into the input of the reference as I do the test "subject."
> 
> bikini, I don't know, I'll have to look into it, I'm in really no position to think right now


That is what the above is doing though Chad. The only difference is that I'm using the 1/8" stereo out rather then the 1/4" out. I measured the 1/4" and 1/8" outputs and they are a direct short, so there is no buffer to be concerned with.

I have also tested this with a tape and distancing the mic from the speaker and it is about the 34mm/ms that you'd expect.


----------

