Order of Importance with setup?

[Ethan Winer]

Chris,

> I did not necessarily mean that no relation existed to resonances <

Okay.

> Such testing should be performed with a system that has little to no bass resonance characteristics <

The only suitable room I know of, and that won't cost big bux to rent, is my living room. You are most welcome to come visit any time. I even have a Windows laptop connected to the system, and suitable software to do all the simulations needed.

--Ethan

 

[Vaughan Odendaa]

Ethan, is ETF still your software of choice, or do you use other acoustic software ? I would like to know. The real time aspect of this software is what I am intrigued with. Being able to find the best location for speakers, for instance, is something that would help me.

I have been thinking about it for some time but I think it would benefit me to get this software because for one, it makes life a lot easier. Who wants to measure their FR and take an hour to do so ? The only thing is getting it up and running, getting the sound card calibrated seems like a real slep. Are there any threads you know of that deal with setting up with ETF ?

I mean, if I can do this, do all these tests, in a matter of seconds, with far better precision and accuracy that I have currently, then I think I am pretty much required to have this power. I don't even know what my room FR really looks like, since the tones you have on your site are not, I assume 1/70th octave resolution.

I took measurements with your software but even then, I don't think it is 1/20 octave resolution or 1/40th octave resolution. I don't know what resolution those tones were taken at.

But the real time aspect is what is enticing to me.

--Sincerely,

 

[Ethan Winer]

Vaughan,

> is ETF still your software of choice, or do you use other acoustic software ? <

I use ETF and R+D, a newer program from the same company that you get for free when you buy ETF.

> The only thing is getting it up and running, getting the sound card calibrated seems like a real slep. <

You can download a demo for free and make sure your sound card etc works before actually buying it.

> I don't even know what my room FR really looks like, since the tones you have on your site are not, I assume 1/70th octave resolution. <

The tones on our site are at 1 Hz intervals, so that makes the resolution 1 Hz. As opposed to some fraction of an octave. Either way, 1 Hz is plenty adequate to see the true response. But tones don't show ringing, and that's at least as important as the raw response.

--Ethan

 

[Vaughan Odendaa]

Sorry Ethan, I asked you if you knew of any threads that go into detail how to set up ETF with sound cards. Just the basic set up.

Thank you for your input. At the moment, I am using my on board sound card that came with my motherboard. The motherboard was purchased 6 years ago. And if I do get a seperate sound card, is it important that I go for an expensive one or just a run-of-the-mill 16 bit full duplex card ?

Concerning test tones, if your tones are at 1hz intervals, and ETF can't measure to 1hz (I assume), then would ETF not be as accurate measuring my FR as compared to your tones ?

Lastly, I have been improving my knowledge in acoustics. Almost every day. I've read Everasts book three times and I am understanding things nicely. I also just purchased "Music, Physics and Engineering by Harry Olson", as recommended by you. I haven't read it yet, but I skimmed thru it and it goes into detail how musical instruments work which isn't what I was expecting.

That was unexpected. But there is a term cropping up on the net that I don't understand. Minimum phase.

For instance, room modes are minimum phase. Now there are various other things which are mentioned that are tied to minimum phase (frequencies below about 30hz become minimum phase) and I'm not sure exactly what they mean by that.

Perhaps you could explain it to me. I would really, really appreciate it.

--Sincerely,

 

[Ethan Winer]

Vaughan,

> Sorry Ethan, I asked you if you knew of any threads that go into detail how to set up ETF with sound cards. Just the basic set up. <

The drawing below is from the ETF help file, and I added the part showing the "Y" splitter which is also needed.

> I am using my on board sound card that came with my motherboard. <

As long as it has separate left and right Line Inputs and Line Outputs, it will work fine.

> if I do get a seperate sound card, is it important that I go for an expensive one or just a run-of-the-mill 16 bit full duplex card ? <

Even "run of the mill" sound cards these days have outstanding specs.

> Concerning test tones, if your tones are at 1hz intervals, and ETF can't measure to 1hz (I assume), then would ETF not be as accurate measuring my FR as compared to your tones ? <

ETF can resolve to 0.7 Hz, so that's even finer than the tones on our CD.

> it goes into detail how musical instruments work which isn't what I was expecting. <

That is very useful information!

> For instance, room modes are minimum phase. <

I'm not a math guy, but according to my expert friend Bill Eppler that term is irrelevant in an acoustics context. That is, you're not missing anything.

--Ethan

 

[Vaughan Odendaa]

Ethan, the sound card that I've seen that I was thinking of buying is a 6.1 sound card. It's really cheap. I spoke to the saleperson and he told me that it has mike in, line in, front out, rear out, centre out. This is for R79 (or about $10 in your currency).

Is this sufficient ? Is there anything else I need to use ETF ? Any specific cables I need ? I have the Radio Shack meter. Thanks a lot.

Oh, the minimum phase thing is just out of curiosity. I don't know what it means and I would really appreciate it if someone could just explain what it is.

--Sincerely,

 

[Ethan Winer]

Vaughan,

> the sound card that I've seen ... Is this sufficient? <

Without seeing specs or even a photo I can't even guess. The key is to have separate left and right line level inputs and outputs. If it has that it will be fine. Again, what's in your computer now will also be fine if it has that.

--Ethan

 

[Vaughan Odendaa]

No, my onboard sound card has a mike in and a line level in. It doesn't have a left in and a right in let alone a left out and a right out.

So you say that the card must have a left and right in and out (line level in or out ?) and it must be able to record and play at the same time. I'll have to look at this. I don't want to spend money on a card that doesn't have these connections.

Other than that, are there any specific cables that I need to use with ETF ? And how would I connect them ? I'm pretty clueless at this point so please forgive me. As I said, I have an SPL meter (Radio Shack), and I assume I'll need to connect a microphone interconnect into the output jack on the side of the SPL meter.

I don't know.

Sorry if I'm making this difficult for you but I am really not too clued up with all these connections.

Thanks again.

--Sincerely,

 

[Ethan Winer]

Vaughan,

> It doesn't have a left in and a right in let alone a left out and a right out. <

You don't need separate RCA connectors. Most sound cards use 1/8 inch jacks, and most are also stereo. Except laptops which often have only a mono microphone input. Also, many sound cards don't have "line output" jacks labeled as such, but if yours has a headphone output that's basically equivalent. I'm just trying to save you the expense of a new sound card, and the hassle of installing new drivers for it etc.

> So you say that the card must have a left and right in and out (line level in or out ?) and it must be able to record and play at the same time. <

Yes. What brand / model computer do you have? Also, if you double-click the little volume control icon in the lower right, you'll call up the Windows audio mixer. There you'll be able to see what sort of inputs and outputs are available.

> Other than that, are there any specific cables that I need to use with ETF ? And how would I connect them ? <

See the etf-setup.gif file I posted earlier.

> Sorry if I'm making this difficult for you <

Not at all! I'm glad to help and I actually enjoy explaining this stuff.

--Ethan

 

[Vaughan Odendaa]

I phoned three computer stores. The cards they sell have front out, and line level in. Even the Sound blaster Audigy does not have seperate left and right out's. It just has front out which encompasses left + right speakers and a line level in. And mike in.

The card I was thinking of is a Genuis sound card. It is 5.1. It has front outs. Center out. Surround out. And a line level in. And a mike in.

Is that sufficient ?

--Sincerely,

 

[Vaughan Odendaa]

I'm not sure what I should do now. The card that I was thinking of is 5.1. It does not have seperate left and right in's and out's. It only has a front out and a line in. And a mike in. It then has center out. Surround outs.

The most expensive card that I saw was R2000 (about $300) and it also only had front out, center out, surround out and a line level in with mike in. Plus some other connections which have no relevance to anything.

I don't know.

--Sincerely,

 

[Ethan Winer]

> The card I was thinking of is a Genuis sound card. It is 5.1. It has front outs. Center out. Surround out. And a line level in. And a mike in. <

That should be fine. "Front Out" is a line level Left and Right output. Hopefully "a" line level input means separate left and right channels. I'm pretty sure it does. It would have to be a lame sound card not to have that.

 

[Vaughan Odendaa]

Ethan, I'll make your life easier. Here :

This is the card that I'm interested in. It's low cost and (hopefully), it has the inputs and outputs necessary. Tell me what you think. Thanks.

--Sincerely,

 

[Ethan Winer]

> This is the card that I'm interested in. <

I'm sure that will be fine.

 

[Vaughan Odendaa]

And if my card has a front out (which doug also tells me should be fine for left and right) then what cable would I need to use there ? Because I've seen the diagram and in it it shows a seperate left and right in and out. If my card has a front out and a line in, what cables do I use ?

Also, the SPL meter has an output jack on the side. What cable do I use there and from where to where does that go ? Sorry for asking rather silly questions but I could sure use your advice in this area.

Thanks again.

--Sincerely,

 

[Vaughan Odendaa]

Sorry to bombard you with more questions, but here is the long and short of it. I bought the card. It is full 16 bit duplex. Play and record at the same time. It has front out. It has rear out. It has centre and LFE out.

It has line in. But not a line out ! It then has a mike in. And a game/midi port. Lastly, it has a cd-in.

That's it. Doug said the card would work. What are your thoughts ? Also, the card that I was using prior was my onboard sound from my Via motherboard.

Must I disable the 97 audio codec in my bios ? And all the onboard sound facilities ? Because I installed the software but the windows sound icon is not present in the front right corner.

Thanks. Sorry about all the questions. I hope you can answer all of them (including my previous post).

Sorry.

--Sincerely,

 

[sploo]

Vaughan,

I can't remember the exact cable setup I used, but it's something like this:

2 x dual male RCA to 3.5mm jack leads, such as http://cpc.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=AV11557&N=411

1 x RCA coupler. CPC do have them, but I can't find the exact part now. It's basically a single female/female RCA block, like one of the lines on this http://cpc.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=AV11794&N=411

1 x RCA splitter. This takes a single RCA male plug (like the ones on the end of the dual male leads) and connects it to two male plugs (i.e 3 x female sockets). I bought one of these http://cpc.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=CN06928&N=411 ... and then used a dual male RCA to dual male RCA on the split output.

With reference to Ethan's pic (post #25):

Connect the jack from one of the leads to your PC line in. Connect the RIGHT RCA (you may need to determine which is L and R using a multimeter) to the mic output on the RS SPL meter. This covers the red line on the left of the pic. There's no separate pre amp needed when using this mic.

Connect the jack of the second lead to the line out/front out on your PC, and connect the RIGHT RCA to the splitter block. Connect the splitter block via whatever RCA leads you need to the L&R inputs on your amp. This covers the red line on the right of the pic.

What you now have is:

1) A mic connected to the RIGHT input on your PC
2) Your amp connected to the RIGHT output on your PC (but the output is split to both L&R on the amp, so the sound should come out of both speakers).

At this point, you should be able to use some sound recording software and record something (and see that the PC only picks up sound for the right input). You should also be able to play music out to the amp, but you'll be hearing the right channel from your PC over both speakers (effectively mono sound).

Now, you'll have both the LEFT RCA male plugs from the leads looking a bit lonely, so connect them together using the RCA coupler. This covers the blue line in the pic.

What this allows ETF to do is to directly record the computer's output into its input. This means that it can compare the true sound to what is output to your speakers, and recorded by the mic.

Hopefully my memory has served me right, and that's long-winded and useful, rather than long-winded and wrong!

Gordon.

PS As for disabling the audio codec; The answer is 'possibly'. When I've installed sound cards on machines with on-board sound it's just worked. However, there should be no danger in disabling the codec and trying, as you can just turn it back on. Check your motherboard manual for info on this. Also, there may be something in the soundcard manual.

 

[Ethan Winer]

Vaughan,

Gordon answered all your cabling questions.

> Must I disable the 97 audio codec in my bios ? <

No.

> And all the onboard sound facilities ? <

No.

> I installed the software but the windows sound icon is not present in the front right corner. <

Go to Control Panel .. Sounds and Audio Devices .. Volume (tab) .. check the box to show the volume control icon.

--Ethan

 

[Vaughan Odendaa]

Wow. Thanks Gordon ! So in other words, my front out is a line out ? And this encompasses both left and right ? So then I'll need a Y adapter perhaps ? I don't have a multimeter. Damn this is confusing.

Would the ordinary person on the street with little computer experience be able to use this software ?

And my line level in ? Would I need a Y adapter for that too ? I assume my line level in encompasses left and right. It's confusing because because I kept hearing that I need a seperate left and right out and left and right out. But I only have a front out and line level in.

And so I searched and searched and searched. No card I saw had seperate left and right out and in's. Not even the most expensive Creative card that I saw. And that's big bucks.

Now I assume you've seen the picture of the card that I've got. Doug tells me that it should be fine though. The card is full 16 bit duplex.

It seems like a rather daunting task to get all these cables. The thing is, I don't think the salesmen at the computer stores will know what I need. Thank you for giving me advise on what I need. I appreciate it.

PS Do these cables (or rather cable requirements) differ from sound card to sound card or do they all basically need the same thing in order to function with ETF ?

Thanks !

--Sincerely,

 

[sploo]

Wow. Thanks Gordon ! So in other words, my front out is a line out ?

Yes, I'd be almost certain that was the case. Basically it's just because soundcards used to be only 2 channel, hence 'line out' but many/most now support 5.1, so the first L&R pair becomes 'front out'.

And this encompasses both left and right ? So then I'll need a Y adapter perhaps ? I don't have a multimeter. Damn this is confusing.

It does. If you look at a 3.5mm jack plug you'll see three segments, one is ground, the other two are the left and right signals (with respect to ground).

If you look at an RCA plug you'll see it has a metal surround (this is ground) and the center pin is the signal. Using a 3.5mm jack to dual RCA lead splits the ground to the surrounds on each RCA, and sends (separately) the left/right signals to the center pins of the two plugs.

I suggested a multimeter because on most cheap leads the RCA plugs aren't marked L & R.

However, as these leads are the norm for connecting a PC soundcard to an amp (because PCs usually have 3.5mm jack sockets, and amps usually have RCA sockets) you could connect your front out to your amp and use some sample playing software (e.g. http://www.goldwave.com/) to play a sample to just the left channel. With a bit of plugging and unplugging, you should be able to work out which RCA plug is connected to the left and right segments on the jack plug.

In the sense that I think you're asking - the lead is effectively becoming a Y adaptor - because it's splitting the left and right signals from the jack socket (PC end) to two RCA plugs, so, no, you don't need a Y adaptor.

Would the ordinary person on the street with little computer experience be able to use this software ?

With a little care, yes. The lead setup is the most difficult, and I had problems getting it to work with the on-board sound on an nForce based motherboard, but once it's installed and the leads plugged in, it's pretty easy.

And my line level in ? Would I need a Y adapter for that too ? I assume my line level in encompasses left and right. It's confusing because because I kept hearing that I need a seperate left and right out and left and right out. But I only have a front out and line level in.

As I've noted, each jack socket on your soundcard is carrying both left and right signals - the jack to dual RCA just gives you an easy way of splitting them.

And so I searched and searched and searched. No card I saw had seperate left and right out and in's. Not even the most expensive Creative card that I saw. And that's big bucks.

Yep, no point really. You're getting all the signals you need over a compact socket, and a row of RCA sockets would be too big for the back of a PCI slot.

It seems like a rather daunting task to get all these cables. The thing is, I don't think the salesmen at the computer stores will know what I need. Thank you for giving me advise on what I need. I appreciate it.

PS Do these cables (or rather cable requirements) differ from sound card to sound card or do they all basically need the same thing in order to function with ETF

The jack to dual RCA cables are ten a penny. Because they're used so much by PCs (to connect to most amps) you should be able to find them in just about any electronics or audio store.

The connectors are a little harder to find, but (in the UK) Maplin, CPC, Farnell etc. will have them. I'd expect RadioShack in the US will have them.

There's tons of ways you could wire everything up for ETF (i.e. different types of leads and connectors) but if the electrical connections (i.e. what's plugged into what) were different, then it ain't going to work...