I have an Acer laptop and would like to measure my room frequency response and other things (spl, group delay, distortion levels) if possible. I would like to get some recommendations on hardware and software to do this.

I have seen the USB sticks with the mini plug in (microphone) and out (to feed system for sweeps and tones) for dirt cheap on eBay (~$1 + shipping). Are they good for this purpose or do I need a better external sound card for accurate measurements? If so waht do you recommend?

What software do I need to get to be able to generate test tones, frequency sweeps and such to capture the results and plot like many of you show on this forum?

I currently have a Sherwood Pre/Pro that I'm sending in to get upgraded to automatically adjust (ParaEq) all my channels from a microphone but I wanted to be able to see a before and after graph of the results.

I would like to keep my total expense for HS and SW under $150.00

Can you guys help me out?

Get RoomEQWizard and an appropriate mic/preamp for it. The software is free and the hardware is less than $150. Go to www.hometheatershack.com for info/downloads.

I have an Acer laptop and would like to measure my room frequency response and other things (spl, group delay, distortion levels) if possible. I would like to get some recommendations on hardware and software to do this.

I use the plain old Radio Shack SPL meter ($50) plus a SB LIVE 24bit USB sound card (~$50) plus Room Eq Wizard (http://www.hometheatershack.com/roomeq/) (free). Works like a charm every time. Other software I know of, but has some sort of associated fees are ETF (http://www.etfacoustic.com/) and TrueRTA (http://www.trueaudio.com/rta_abt1.htm). Not sure about the hardware requirements for them though.


Scott

Get RoomEQWizard and an appropriate mic/preamp for it. The software is free and the hardware is less than $150. Go to www.hometheatershack.com for info/downloads.

Kal, I have a microphone & preamp that came with my Sherwood Newcastle Pre/Pro for calibration purposes, would that work fine? One thing Is that the Pre-amp has an RCA output. Would a USB dongle with mic input be needed?

Thanks,
MT

I use the plain old Radio Shack SPL meter ($50) plus a SB LIVE 24bit USB sound card (~$50) plus Room Eq Wizard (http://www.hometheatershack.com/roomeq/) (free). Works like a charm every time. Other software I know of, but has some sort of associated fees are ETF (http://www.etfacoustic.com/) and TrueRTA (http://www.trueaudio.com/rta_abt1.htm). Not sure about the hardware requirements for them though.


Scott
Scott,
Thanks for the reply. One question though.
I've read that the RS SPL meters are only accurate for bass region. What do you do to correct for that in the higher frequencies?

Actually, since I posted this in the Bass forum,:rolleyes: I guess that since I'm going to invest $$, I wanted a solution that would measure the whole audio frequency spectrum.

Kal, I have a microphone & preamp that came with my Sherwood Newcastle Pre/Pro for calibration purposes, would that work fine? I have no idea about that.

One thing Is that the Pre-amp has an RCA output. Would a USB dongle with mic input be needed?Doesn't your PC have a line-level input or two?

I have no idea about that.

Doesn't your PC have a line-level input or two?

I had to wait until I got home to look at the laptop. It use to be the wife's so I wasn't sure. So yes it does have the typical 3 mini jacks. Mic (red), headphone out (green) and a blue one that I'm not sure what it's for.

Can this be directly used to plug in microphone, and provide output to amp to drive speakers for testing?

I had to wait until I got home to look at the laptop. It use to be the wife's so I wasn't sure. So yes it does have the typical 3 mini jacks. Mic (red), headphone out (green) and a blue one that I'm not sure what it's for.

Can this be directly used to plug in microphone, and provide output to amp to drive speakers for testing? You cannot usually use the mic input on the PC; they are too noisy. You use a line level input with an external mic preamp. Why don't you take a look at the REW pages I listed and see what others use?

You cannot usually use the mic input on the PC; they are too noisy. You use a line level input with an external mic preamp. Why don't you take a look at the REW pages I listed and see what others use?

Kal,

I have looked at those pages and read the FAQ list. Lot's of good info there. I'm trying to decide between the TrueRTA(what Craigsub uses) and the REW. Looks like the TrueRTA is more powerful but that power comes at a price. I guess I'll use the calibration mic/pre amp that came with my pre/pro for my measurements since it will be what is used when the pre/pro auto equalizes. thanks for your help.

Mike

Scott,
Thanks for the reply. One question though.
I've read that the RS SPL meters are only accurate for bass region. What do you do to correct for that in the higher frequencies?

Yes, the RS SPL meter is inaccurate...but, the good news is that it's predictably inaccurate. There's an option in REW to load a "calibration file" for the SPL meter that adds in the necessary correction factors. Getting a real mic would be a better way to go, but if you have one laying around, the RS meter is suitable when used with the calibration file. I don't know how accurate the mic that you'd be using is, but if it's a relatively common mic, there might be a correction file available for that too (if it's even necessary).


Scott

Kal,

I have looked at those pages and read the FAQ list. Lot's of good info there. I'm trying to decide between the TrueRTA(what Craigsub uses) and the REW. Looks like the TrueRTA is more powerful but that power comes at a price. TrueRTA will not do room mode analysis or time-based analysis.

I guess I'll use the calibration mic/pre amp that came with my pre/pro for my measurements since it will be what is used when the pre/pro auto equalizes. Your pre/pro has a built-in correction curve for that mic which you will NOT have in your measurements. You need a separate FLAT (or calibrated) mic.

TrueRTA will not do room mode analysis or time-based analysis..
So even the more expensive models at $69 or $99 won't do room mode or time-based Analysis? Very good point. Thanks.

Your pre/pro has a built-in correction curve for that mic which you will NOT have in your measurements. You need a separate FLAT (or calibrated) mic.
I never thought of that. I'm going to check with Sherwood Newcastle about obtaining that correction file and if not available, I'll just buy a new microphone like you suggested. I can possibly use my Mic pre-amp that came with the pre/pro? Something I can also ask Sherwood about. Their customer/tech support seems very good.

Yes, the RS SPL meter is inaccurate...but, the good news is that it's predictably inaccurate. There's an option in REW to load a "calibration file" for the SPL meter that adds in the necessary correction factors. Getting a real mic would be a better way to go, but if you have one laying around, the RS meter is suitable when used with the calibration file. I don't know how accurate the mic that you'd be using is, but if it's a relatively common mic, there might be a correction file available for that too (if it's even necessary).
Scott

Since I don't have a RS SPL meter and I'm going to go the route of using more powerful software for measurements, I guess I'll pick up a microphone if I need it.

Thaks a bunch for your responses. This helps a lot.

I never thought of that. I'm going to check with Sherwood Newcastle about obtaining that correction file and if not available, I'll just buy a new microphone like you suggested. I can possibly use my Mic pre-amp that came with the pre/pro? Something I can also ask Sherwood about. Their customer/tech support seems very good.



Since I don't have a RS SPL meter and I'm going to go the route of using more powerful software for measurements, I guess I'll pick up a microphone if I need it.

Thaks a bunch for your responses. This helps a lot.I suggest you start with an RS SPL meter which you can use as-is or with REW. I would not mess with trying the Sherwood mic and, besides, this way you can use them simultaneously. :D