Hi Kevin,

I had a similar problem with my laptop and SB USB MP3+. It seemed the computer's AC signal was somehow leaking into the audio out on the SB.

Disconnecting the AC and running solely on the battery while doing measurements solved the problem.

Hope this helps. :)

--Wayne

Thanks Wayne, I read that before but I forgot about that :D

That would explain why I was still hearing the heartbeat sound after closing the REW, closing all programs on my laptop then disconnecting and reconnecting the MP3+ from and to the laptop

Hi John,

Since I have not heard back from Behringer, I contacted Sound On Sound magazine in the UK yesterday, with a request to help get you a real live DEQ2496 to assist you in adding that capability to REW.

They did respond to let me know the message was received (a real person, not an auto-response), so let's see what happens ...

BTW, I am somewhat flabbergasted that out of the 10 frequenters of this forum who asked you to include capability for the Behringer Ultracurve Pro, not one has chimed in with an offer or suggestion as to how to get a unit to you.

Like the yin without the yang, "take" doesn't work without the "give". That's why it's called "give and take". Go figure! :rolleyes:

Cheers all, :)

--Wayne

Ok, I finally got the REW up and running last night, nice program once it is all set up. After running my sweeps I only have one peak that needs to be adjusted at 31.5Hz, this is going between 30Hz (where my current sub drops off at) and 80Hz.

I will be getting a new sub in about a month but I am curious, how do I actually setup a house curve? I thought that there were some settings that were pre-loaded in the program, but I see that I have to do it manually.

John -
Looks like an excellent program but I would hate to pull out the old PC. Cut that cord and went all Mac. Equipment of choice would be a G4 iBook with Powerwave from Griffin, also have an iMac G5 available. Any progress on working out the Mac bugs? Currently everything loads and even outputs, can't seem to find a trick to make it recognize inputs.
Thanks for all your efforts,
Joel

Work on the Mac issues is in progress, but it will be a while before there is a more mac-friendly version, probably April.

Hi John,

Since I have not heard back from Behringer, I contacted Sound On Sound magazine in the UK yesterday, with a request to help get you a real live DEQ2496 to assist you in adding that capability to REW.

They did respond to let me know the message was received (a real person, not an auto-response), so let's see what happens ...Seems like that was a good route Wayne, I've had an email from Behringer about getting a unit, watch this space... :)

Looks good on you, John. Thanks for all your diligent and brilliant work!

Will stay tuned ... :D

-- Wayne

What is needed besides your software? Is a microphone needed? Speakers for the PC? What else is needed?

Visit the link in the first post on this thread, and read the user's manual.

hi there

Have a beginner question; was going to get some mics and measure the phase of my speakers (last time visitors said they hear wrong phase and large spl differences between left and right), following this webpage :

http://www.ymec.com/hp/signal2/check02.htm

Can RoomEQ do phase measuremt from speakers ? I'll am wonder about ETA ... reason I backtrack is I already have a Radio Shack SPL meter

thanks
jeff

I am learning how to use this great tool. I run a toslink cable from my PC to the AV reciever and run my RS SPL meter from the soundcard to the living room via a 20' RCA cable. I am able to get some great measurements, but it is rather painstaking for me to adjust all speakers individually.

What I would like to do is just run my Avia sweeps and get measurements that way. Is there any way to do this? This would allow me to adjust each channel independently without physically disconnecting each speaker (except the one I am measuring) as I do with the current setup. My soundcard will not output 5.1, 6.1 or 7.1.

I apologize if this has been answered already. I did not read the entire thread.

Thank you very much.
Keith

I did find some info on posts 560 and 561. Thank you.

Whats a good calibrated microphone to use with this software? I'm currently messing around with other software, but will switch to this and give it a try. But in the end I still need a calibrated microphone to get accurate results.

You've developed a terrific product!

I've got the capability to feed my multichannel receiver directly from my PC via a Toslink/coax cable .... I go USB to an Empirical Audio USB to coax converter, which uses the MAudio Transit USB software/drivers.

Is there any way to "direct" the output of REQ to my three front and two surround speakers "independently"? Currently I have to swap out RCA cables on the back of the receiver (eg, switch the "left" output from REQ to the center channel input to measure that way.) It sure would be more convenient if there was some way to "route" the REQ output to a specific channel of a 5.1 (or even better 7.1) setup.

Figure there must be some "sound card" type functionality or plug in that would do this?

Hi Bruce,

No way to do that at the moment. Would need to generate a DD or DTS stream with the test signal in the relevant channel, but that would need a DD/DTS encoder and the encoder compression would also have a big impact on the measurement.

Whats a good calibrated microphone to use with this software? I'm currently messing around with other software, but will switch to this and give it a try. But in the end I still need a calibrated microphone to get accurate results.Buy a Behringer ECM-8000 and use the correction files included in REQW

Could someone direct me to the post or provide the info on how I use the RS SPL meter correction files? Is there one post that explains the process? I just don't understand I guess how to turn a .txt file into a .cal file.......then do I import it into REW or what?

Guys, I have a quick question:

When I load up the mic calibration file for my RS SPL meter I get a line that appears below my target line for the low frequencies and then it rises until it eventually meets up with the target line. Should my bass be following the Mic Cal line or should I be ignoring it?

Guys, I have a quick question:

When I load up the mic calibration file for my RS SPL meter I get a line that appears below my target line for the low frequencies and then it rises until it eventually meets up with the target line. Should my bass be following the Mic Cal line or should I be ignoring it?

Nice theater there. Continuing my original question, how did you "load up" the cal file?

Nice theater there. Continuing my original question, how did you "load up" the cal file?

On the same page that you download REW, you download the CAL file for your SPL meter. You then click on Meter in the Room EQ Wizard and click on load calibration file.

Thank you. The file loaded, and I see the "curve" for the meter. It's too late for me to take a measurement tonight, but am I to assume with this file loaded, all subsequent measurements will now be "corrected" somehow with this file? In other words, is there anything else I need to do other than load the file?

Thank you. The file loaded, and I see the "curve" for the meter. It's too late for me to take a measurement tonight, but am I to assume with this file loaded, all subsequent measurements will now be "corrected" somehow with this file? In other words, is there anything else I need to do other than load the file?

You see, that's what my question is. You'll notice that the 'target' line eventually evens out and the 'mic cal' line also evens out. I THINK you're supposed to take the mic cal line and slide it up until each of the two lines is level with each other. I THINK you're supposed to then use the mic cal line INSTEAD of the target line and set your filters so that your reading matches your mic cal line... I THINK :rolleyes:

Please please please.... someone... anyone... correct me if I'm wrong here because I'm not entirely sure.

The mic cal file is used by REW to apply corrections to measurements you make. You only need to load the file, you don't need it to be shown on the graphs and you don't need to make any other use of it. For detailed help on using REW read the help files :) and use the support forum at www.hometheatershack.com/forums/bfd-rew-forum

Thanks John.

The mic cal file is used by REW to apply corrections to measurements you make. You only need to load the file, you don't need it to be shown on the graphs and you don't need to make any other use of it. For detailed help on using REW read the help files :) and use the support forum at www.hometheatershack.com/forums/bfd-rew-forum

Aaaaaahhhhhhhhhhh!!!

Thanks :D

I hope someone can help me with this. Last night I was attempting to use REW to setup my subs, following the help file I calibrated my external soundcard without problem. The problems began when I attempted to set my levels, no matter what I did I couldn't get my levels to play any louder than about 64db on my spl meter. I have a Denon 987 receiver and I had it turned up to max with still no luck.

Unless I can get the levels up to 75db on my meter, the plot of my subs comes out way below the level line.

Thanks in advance

I can't access Home Theater Shack from work so I am hoping someone here can help me. I setup my bfd using REW but I am not sure if my input level is too low or high? Last night I was watching part of Flight of the Phoenix and parts of it had the red lights on my bfd maxed out. I was watching a at -8 from reference so I don't believe I had reached the limits of either my sub or amp. My subs level is currently set for -7.5, should I turn the input level from the receiver down and the sub output up to help prevent clipping?

Kevin, I think when the BFD filters are on (not in Bypass mode), the red light indicates clipping of the BFD output. Do you have filters with many dBs of boost. If so, that explains why. Generally I keep my boosts to less than 5 dB.

A little confused on the wiring-- the more common setup seems to be as posted in the attached jpeg. However, I have found a few references on the web where the
left channel of the pc output is connected to the left channel of the pc line in. I do not understand why one would want this feedback loop in place. Should it be left disconnected at all times? Tnx.

Kevin, I think when the BFD filters are on (not in Bypass mode), the red light indicates clipping of the BFD output. Do you have filters with many dBs of boost. If so, that explains why. Generally I keep my boosts to less than 5 dB.

None of my filters are set to boost any frequencies, only cut them. Since posting my question I decreased the input level about 2 db and adjusted the volume on my subs and so far I haven't had any clipping issues.

Hi everyone, I've just had a little play with REW and am impressed by its features, but it stumps me in a couple of places.

I purely want to use it to get a -3/-6db frequency response of my system at the moment with and without the subwoofer.

How do I interpret the results to show me this?

Is it the amount of db below the target level which relates to these numbers or am I way off?

Hi everyone, I've just had a little play with REW and am impressed by its features, but it stumps me in a couple of places.

I purely want to use it to get a -3/-6db frequency response of my system at the moment with and without the subwoofer.

How do I interpret the results to show me this?

Is it the amount of db below the target level which relates to these numbers or am I way off?

I recommend that you consider peaks and dips above and below the target level. Well, you would know where to get comprehensive help - where you found REW. In case you had the old version, you should consider getting the latest version.

Brucemck2,
I've been looking for the exact same feature as you do, and i guess there must be the way
to achieve that tweaking the os, but i'll be damned if i know how :(

I played a bit with graphedit, but without success, i also tried to ask on the HTPC
section, again without success :mad:

The sad part is that i strongly doubt that John will be able to insert such a feature
in future versions of REW, since DD and DTS encoding are subject to royalties, afaik.
Maybe it could obtain the same purpose (at least for me) if it could use test signals
recorded on a DVD (white noise/pink noise/MLS/Whatever).

JohnPM,
Cheers, this is Zaphod from studiotips, just thought this was a bit too HT related
for the acoustics guys there :D

My set up includes a Velodyne DD15 that came with a mike that appears to be a Behringer 8000. The mike has the XLR connector. I wish to use it as a calibrated mike with REW.

Is this a good plan?

Is there a simple adapter I can use that will match the impedance and supply the 48vdc phantom power needed to juice the mike?

John

Is there a simple adapter I can use that will match the impedance and supply the 48vdc phantom power needed to juice the mike?You'll need a mic preamp that supplies phantom power, a few people on HTS use Behringer's UB802 (http://www.hometheatershack.com/forums/bfd-rew-forum/1117-ecm8000-how-do-i-set-up.html) though I think it has been replaced by the Xenyx 802.

My set up includes a Velodyne DD15 that came with a mike that appears to be a Behringer 8000. The mike has the XLR connector. I wish to use it as a calibrated mike with REW. Well, you would have to have it calibrated. Otherwise, the exact frequency response is undefined.

Is there a simple adapter I can use that will match the impedance and supply the 48vdc phantom power needed to juice the mike? I've had good results with the M-Audio MobilePre.

So I ran Room EQ Wizard for the first time, and this is what I got on my JL F113, not very impressive to me. What are your thoughts?

So I ran Room EQ Wizard for the first time, and this is what I got on my JL F113, not very impressive to me. What are your thoughts?

In general, that's not too far off from a sub plot. Never mind the peaks- they can be EQ'd out. The crossover could be better. Try running the test signal through the pre/pro or receiver whichever you use, so that you can use the bass management of the prepro or receiver.

JL F113- Bass Traps in all 4 corners - Jl Set to Ref and Crossover at a tick past 75

What do you think, these were taking a 9 differn't spots around the room.

http://i151.photobucket.com/albums/s152/1984911Porsche/52607.jpg

The valleys at 35-42Hz are very consistent, and are not easily fixed. You might try opening some windows/doors to see if that helps to fix the destructive interference (aka cancellation).

Other valleys are dependent on speaker placement. You could fill them by the use of multiple subs. A second lesser sub that's good to 25Hz will help fill the valleys in the 26-32Hz range.


In the 55-120 Hz range, you could use another sub that can rumble to 35Hz, to fill the valleys.

Did you play with the phase at all?

OK, here's the deal.

I've used REQW before (on a computer that I no longer have) so I'm somewhat familiar with the setup/calibration/measurement process. That computer was equipped with an older version of REQW and had a SB Live Value sound card. The mic was a Rat Shack SPL meter.

Yesterday afternoon and a good chunk of the evening, I spent trying to make the newest version of REQW work on the computer I have now. This new computer has a Gigabyte P965-S3 mobo with on-board sound that uses Realtek ACL883 chipset, and I'm trying to use the same RS SPL meter I used with my old setup. REQW is the latest version 4, freshly downloaded from HTS one day ago.

The first problem is that no matter what I have done so far, I cannot get a sound card calibration to work properly. If I select the input as line-in, the system sees an incoming signal even without a loopback jumper connected.

I have looked high and low and the only thing I can find that may be some type of monitor function is a setting called "stereo mix". I've tried selecting and de-selecting this option and it seems to make no difference.

The second problem is that if I skip the soundcard cal part and go straight to the SPL meter cal and measurements, the SPL meter part seems to cal properly, but when I attempt to make a measurement, it seems like it's doing that, for lack of better terms, internal loopback thing again. The response curves generated look exactly the same each time and I believe represent the mirror image of the RS meter cal file.

I'm stumped... any thoughts on what I'm doing wrong or where I can find the magic button I'm missing?

I've spent hours scouring the settings of REQW and the Windows (XP) and Realtec properties to the point of becoming extremely frustrated; I know it's gotta be something simple. :confused: :mad:

Help, Mr. Wizard...

Dunno what fixed it for sure, but I uninstalled the Realtek drivers, loaded in the newest version (mine were two revs old), cleared all the settings from REQW, and started fresh.

Worked first time through with no hitches....

This tool seems to only correct frequency response. But sophisticated systems like TACT also do phase correction. Is that possible on a PC? Am I missing something?

I'm considering a portable solution to use REQW.

The first conclusion is the M-Audio Mobilepre and the Behringer mic.

Are their any other contenders that I should look at that offer better performance for around the same cost?

whoaru

Here is another option that you should consider. Its fairly small too.

http://www.guitarcenter.com/shop/product/buy_maudio_audio_buddy?full_sku=100387450

Also, figure into your total cost, the cost of having your mic calibrated.

I am getting clipping error when i match the input and output level at -12 dB. The soundcard is a x-fi extrememusic. And I have to increase the output volume to 0.75 for that. Wave and input volumes are at 1.00.

What does that mean?

Thank you.

Sorry all,I figured it out, quite obvious from the response curve that I had boost on. I found them under advanced settings and brought them back to normal.

Ironic with a nickname like this, I missed out on the treble and bass boost :-)

if i am using the radioshack spl meter should i have it in max mode or the normal mode?

Normal mode, c weighting, slow

I have a problem configuring REW 4.00 for my input source. Configuration:

Windows Vista Business, 32-bit
TurtleBeach Audio Advantage SRM, USB audio device
Radio Shack digital meter
Dell D830 Laptop

I successfully configured REW to play audio through my receiver. However, configuring the input is not working for me.

In the TurtleBeach control panel, I selected the Line In and when I turn the RS meter on, the bar graph in Turtle Beach dances around in sync with external stimulus. In addition, through the main speakers I can hear the line-in input and I get feedback if the volume is up too high on my receiver. So I know the sound card is getting input from the RS meter.

In REW I've selected every "input device and input' option available. However, the Input meter inside REW never shows any activity, even though the input levels in the Turtle control panel applet show activity.

How can I make REW get the line-in input signal? I'm a very technical user, so I don't think it's just something dumb I'm doing. Since Turtle sees the audio levels, I'm confident I have the wiring setup correctly.

Can anyone offer some input? Without this working I'm obviously dead in the water.

Thanks!

Hello:

While I love AVS, HomeTheatherShack seems to have the REW-philes more so then here.

Check out their REW forum. You may find someone there with the same setup.

http://www.hometheatershack.com/forums/rew-forum/

Splotto

I have a problem configuring REW 4.00 for my input source. Configuration:

Windows Vista Business, 32-bit
TurtleBeach Audio Advantage SRM, USB audio device
Radio Shack digital meter
Dell D830 Laptop

I successfully configured REW to play audio through my receiver. However, configuring the input is not working for me.

In the TurtleBeach control panel, I selected the Line In and when I turn the RS meter on, the bar graph in Turtle Beach dances around in sync with external stimulus. In addition, through the main speakers I can hear the line-in input and I get feedback if the volume is up too high on my receiver. So I know the sound card is getting input from the RS meter.

In REW I've selected every "input device and input' option available. However, the Input meter inside REW never shows any activity, even though the input levels in the Turtle control panel applet show activity.

How can I make REW get the line-in input signal? I'm a very technical user, so I don't think it's just something dumb I'm doing. Since Turtle sees the audio levels, I'm confident I have the wiring setup correctly.

Can anyone offer some input? Without this working I'm obviously dead in the water.

Thanks!

The biggest issue that users have been having is due to Vista. Apparently Vista handles sound differently than Xp. Make sure you have the latest Vista compatible drivers for your sound card. Be sure to post on hometheatershack as there have been a number of users who have had problems with Vista. Me being one of them.

I do have the Target volume set slightly higher, however, I dont think that would matter. Currently I have some "wonky" issues between 15-40hz. My question is, would the location have a lot to do with this? Currently my Apartment isn't in the best of shape, old wood floors, plaster walls, and a fire escape support are factors that, I think, are contributing to this.

But, I thought I would get some opinions on what they thought about my current graph and possible solutions to correcting it.

REW Sweep (http://www.hometheatershack.com/forums/attachment.php?attachmentid=6332&stc=1&d=1203625585)

I was wondering if someone can help me with a question I asked in a different thread?

See the attachment (http://www.avsforum.com/avs-vb/showpost.php?p=14284149&postcount=1319) for my question.

Thanks

You set REW to the reference level that you use. This could also be done by using an external test tone such as your reciever to tell REW what your reference level is set at more accuratly. It is under calibrate SPL - use external source. If you know that your subwoofer is setup correctly already and just want to measure, use the identical SPL level.

Thanks Steve, that is what I did.

How do I determine if the integrated sound card in my laptop is sufficient for taking basic speaker/sub measurements? Laptop is equipped with line in and headphone/line out ports. Plan to use with Radio Shack analog SPL and Proc combo. No EQ.. just need to take basic measurements.

Vista, at the OS level, has a substantially-improved volume control that uses sophisticated techniques to ensure good fidelity. My understanding is that Windows 7 uses something similar, if not better.

I can't get this thing to work and I think it is my sound card. What sound card should I use that is very inexpensive? The one I have as far as I can tell (I am about useless when it comes to computer stuff) is a Soundmax digital audio.

Thanks
Moto

I can't get this thing to work and I think it is my sound card. What sound card should I use that is very inexpensive? The one I have as far as I can tell (I am about useless when it comes to computer stuff) is a Soundmax digital audio.

Thanks
Moto

is that "n board" audio? does it have line in/out? i use soundblastrer live external

I'm thinking of giving REW a try. I am pretty sure that the phase on my subwoofer is not matched as well as it could be with the front speakers and I only have a 0 or 180 degree switch on my sub (HSU STF-2). I would like to adjust the speaker distance of the sub to account for any phase mismatch. Is it possible to measure the phase difference between a subwoofer and front speakers using REW ?

How do i tell which soundcard my computer has? I went to my computer options and it says my mixer device is a soundMAX digital audio. Is that correct?

I have a 6 year old computer. Its a dell demention 2400. Is the soundcard good enough for REW? Im planning on getting a laptop but i've heard alot don't have line in's?

If it has a line in and a line out (not to be confused with a mic in and a headphone out) chances are it'll work. If you get a laptop without line in/out, you could always get an external soundcard that connects to the computer via USB.

As for pahse difference, (the previous poster) with REW this is usually done by taking two scans, flipping your phase switch in between, and sticking with whichever position yields the smoothest scan in the crossover area.

Well the properties for my mixer device says

Volume contol
wave
SW synth
CD player
Microphone
Line in
Phone
Mono out

Line in and a couple others are checked.

As for a laptop, im currently looking what kind to buy. Would the specs list if it has a line in and out?

Well the properties for my mixer device says

Volume contol
wave
SW synth
CD player
Microphone
Line in
Phone
Mono out

Line in and a couple others are checked.
If Line in and mono out aren't grayed out, there's a good chance that'll work.
As for a laptop, im currently looking what kind to buy. Would the specs list if it has a line in and out?
Kind of depends on what each manufacturer wants to put in the specs.

No they aren't grayed out, im able to check and uncheck them.

As for use. After i get an spl meter, i plug the cable into the line in and another cable into the line out and into the receiver? This will be my first time using this program.

Saprano -

Here's everything you'll need to get started with REW. Keep in mind, this is not a plug and play program and it will take some effort and time to learn how to use it. If you want plug-n-play, buy the "XTZ Room Analyzer". http://www.xtz.se/uk/products/mearurement-system/room-analyzer

1. Download Room EQ Wizard for free.

http://www.hometheatershack.com/roomeq/

2. Buy this calibrated microphone:

http://cross-spectrum.com/measurement/calibrated_behringer.html

3. Buy this microphone preamp:

http://www.amazon.com/M-Audio-MobilePre-USB-16-bit-stereo/dp/B000L9RNKA

4. Get a mic stand, with a telescoping arm, like this:

http://www.amazon.com/Stage-Spotlight-Tripod-Microphone-Stand/dp/B0002E55UY/ref=sr_1_1?ie=UTF8&s=musical-instruments&qid=1247372345&sr=1-1

5. Buy a 30 - 50 foot XLR mic cable:

http://www.amazon.com/NADY-XC-50-XLR-Microphone-Cable/dp/B00009W40H/ref=sr_1_5?ie=UTF8&s=musical-instruments&qid=1247372458&sr=1-5

6. Get an RCA to 1/4 inch phono cable (this one is used to send the test signal to your sound system):

http://www.amazon.com/HOSA-CPR204-Dual-4-Inch-Plugs/dp/B000068O19/ref=sr_1_6?ie=UTF8&s=musical-instruments&qid=1247372678&sr=1-6

Total investment: around $250 for very competent sound analysis tool. The Room EQ Wizard software is phenomenal, and there is a large support group on http://www.hometheatershack.com/

To buy the XTZ Room Analyzer, you need to order it directly from XTZ in Sweden by following these directions:

International orders
You can order by sending an email to: info@xtz.se
Please state your:
name
address
country
phone number
and the products you wish to purchase
They will email you the total cost (including shipping) and explain how payment is made.

Thanks for that rundown hifisponge!

A little more difficult than i thought. Im sure the learning curve will be worth it though.

The REW V5 Beta version will be available for download sometime this weekend, there's a quick overview of the new features here: http://www.hometheatershack.com/forums/REWv5_Beta/

I found this thread and noticed no activity for half a year... Can somebody enlighten me a little? I want to use REW for my small listening space. I would like to try full range equalizing, but will start with the subwoofer until I get the hang of the program. I am in over my head here...

The dream I am chasing is to use REW and the Electri Q equalizer in real time to equalize my stereo speakers and subwoofer.

My computer is the source:
Onkyo SE-200 PCI sound card
Foobar 2000 with a VST editor and Electri Q equalizer VST plugin

I want to use Electri Q as the only equalizer. If REW gives me filter settings to equalize my reponse curve, it seems I will have to manually enter the filter settings into Electri Q. The problem is, once they are entered, I do not see a way to verifying the equalized response because the sound is only equalized if it is coming from Foobar.

Page 13 of this thread mentions using Foobar and a convolver appoach to get the filter settings imported into an EQ. Also, a line-in plugin in Foobar could be the ticket...

I am tempted to purchase the equipment as mentioned above (money is tight) but I would like to know whether REW will not be a good solution for me. I may resort to a SPL meter and a test CD.
Thanks in advance.

avsnoob -

You're right that without the ability to send the test signal through foobar you won't be able to verify the the results, however, the predicted results given to you by REW are pretty darn accurate, so you could just set the filters and trust that the results will match REW's prediction. Or, you can rip a pink noise track into your PC, play it back through Foobar with the EQ filters engaged and use the "spectrum analyzer" function of REW to verify the results. This is not as accurate as using the logarithmic sweep tone in REW, but it could be an acceptable work around.

An SPL meter is just too inaccurate to use for meaningful frequency response measurements. It could give you a general idea of the in-room bass performance, but an SPL meter should absolutely not be trusted for mid and high frequency measurements.

As far as having to set the filters manually, this is no big deal. You shouldn't have more than 6-8 filters per channel for L/R and 3-5 more for the sub. All you need to enter for each filter the frequency, gain and bandwidth. Probably 30 minutes of work for all channels.

Let me know if you have any more questions, and be sure to check out the REW section on www.hometheatershack.com.

Thank you for the valuable feedback.
I will likely just use the predicted equalizer adjustments from REW with Electri Q. I am also looking into the Oxford EQ with Foobar.
Currently, my EQ works on both stereo channels simultaneously. I am working on a way to run an instance of the EQ plugin for each channel.


I am curious if anybody recommends one of these mikes over the other. The precalibrated unit from Cross Spectrum is more expensive, but should alleviate headaches for noobs like me. I noticed the calibration files on the HTS REW forum, but I haven't figured out how to use the calibration file yet (never owned a decent mike, I am seriously a noob.) I know that the calibration file is an average, so it could vary a lot depending on the sample I receive.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=390-801

http://cross-spectrum.com/measurement/calibrated_behringer.html


Does anybody recommend one of these MobilePre units over another? The new one has ProTools SE, the line output is dual rca vs 1/8", and some other differences. I'm sure they both will get the job done, but the new one is about $40 more.

http://www.m-audio.com/products/en_au/MobilePreUSB.html

http://www.m-audio.com/products/en_us/MobilePre.html


Lastly, is it okay to choose an arbitrary value in REW for the SPL meter range? I wanted to avoid purchasing a RS SPL meter is possible, I just want the room reponse to be even.
Thanks again!

If you want accurate results, buy the Cross Spectrum mic.

I haven't used the preamp in your second link, but I know the first one works.

You can use a somewhat arbitrary level for your measurements, but it throws another variable into the mix that I wouldn't recommend adding since you are new at this. You also have to make sure that the test tone is played back high enough above the noise floor of your room.

Having the EQ applied to both channels will only work for "room correction" if both speakers are placed identically within a completely symmetrical room. :)

http://www.hometheatershack.com/forums/rew-forum/

I'd like to say I downloaded REW5 and it is a significant upgrade from v4.
Plus, it works 100% fine on my 2007 iMac running OSX 10.6.6, using the M-Audio Mobile Pre-USB.

Great job John!

Here are screen shot of settings for ref.
I also download/used the M3DMixer as suggested elsewhere @ HTS:
https://lh6.googleusercontent.com/_FqTNmgNQHz8/TVgrVwaS15I/AAAAAAAAMMA/z2gLhMUDB_Q/s800/REW5%20settings.jpg

I'm NOT asking for analysis of these - there are other places for that, just sharing them as REW5 user interface output:
Here are graphs of my IB sub, no EQ, with the treatments as show earlier here:
(fwiw, my 2nd seat riser is also a broadband bass trap as well)
2nd row all 4 seat positions
https://lh4.googleusercontent.com/_FqTNmgNQHz8/TVdubFtIfRI/AAAAAAAAMLg/AxAv9KmK5VI/s800/rew%20feb%2012%202011%205-200hz.jpg

1st row all 3 seat positions
https://lh6.googleusercontent.com/_FqTNmgNQHz8/TVdzRBsKycI/AAAAAAAAMLs/pRPtDRDrNKg/s800/rew%20feb%2012%202011%201st%20row%205-200hz%20third%20oct%20smooth.jpg

will a computer onboard soundcard be a sufficient preamp?
im looking at the behringer mic (dont have model# off hand, but it's the common one priced around $50).

is there a relatively inexpensive mic preamp out there that i could use (if my computer's onboard sound is not useful)?

will a computer onboard soundcard be a sufficient preamp?
im looking at the behringer mic (dont have model# off hand, but it's the common one priced around $50).

is there a relatively inexpensive mic preamp out there that i could use (if my computer's onboard sound is not useful)?

http://www.avsforum.com/avs-vb/showthread.php?p=18486257#post18486257 :)

hifisponge, I think he was asking for something more reasonable than the original poster mentioned, which was $176 from amazon.. I'd be in the same boat, its a lot of money for something thats just going to amplify the input signal a bit... Is it absolutely necessary?

will a computer onboard soundcard be a sufficient preamp?
im looking at the behringer mic (dont have model# off hand, but it's the common one priced around $50).

is there a relatively inexpensive mic preamp out there that i could use (if my computer's onboard sound is not useful)?

http://www.avsforum.com/avs-vb/showthread.php?p=18486257#post18486257 :)

+1 what hifisponge (Tim) said, here is a pict of the pre-amp in action 2 years ago doing nearfield subwoofer measurement
(for set-up, just follow the instructions in the links posted and REW help info also)
https://lh3.googleusercontent.com/_FqTNmgNQHz8/SXl7urRnr3I/AAAAAAAAMG8/rTIh7ttWojE/s400/IMG_9401.JPG

hifisponge, I think he was asking for something more reasonable than the original poster mentioned, which was $176 from amazon.. I'd be in the same boat, its a lot of money for something thats just going to amplify the input signal a bit... Is it absolutely necessary?

?? $75 from amazon, same as mine
http://www.amazon.com/M-Audio-MobilePre-USB-16-bit-stereo/dp/B000L9RNKA

the original link given was from amazon and was $176
I'm not sure if those are the same models but yes that is a better suggestion in terms of price.. I was just stating that the original post that they linked to was for the $176 version, a better answer would have thus been your answer than to just go back and look at the previous post that was made in the same thread.

hifisponge, I think he was asking for something more reasonable than the original poster mentioned, which was $176 from amazon.. I'd be in the same boat, its a lot of money for something thats just going to amplify the input signal a bit... Is it absolutely necessary?

?? $75 from amazon, same as mine
http://www.amazon.com/M-Audio-MobilePre-USB-16-bit-stereo/dp/B000L9RNKA

the original link given was from amazon and was $176
I'm not sure if those are the same models but yes that is a better suggestion in terms of price.. I was just stating that the original post that they linked to was for the $176 version, a better answer would have thus been your answer than to just go back and look at the previous post that was made in the same thread.

I made that list a while back and it seems that the link to the mic preamp was for one that that had gone up in price (common on Amazon). I've updated my list with the link mtbdudex provided since the two preamps function the same.

I don't know what localhost considers cheap, but to me even $176 still falls into the low range. It's all relative.

As far as my post to the list in the thread, it is all too common for newer members to skim over what has already been provided. I was simply pointing him back to info that he may have missed.

If you're looking at the Beringer mike I think you are it needs phantom power. Most consumer sound cards don't supply this. I picked up a Rolls mike amp that does along with cabling at Parts Express. IIRC it was around $50 a couple years ago. It runs into a line input on your PC vs a mike input then. Probably not the ticket if you're setting up a studio but seems to do ok getting relative changes in room response for moving speakers or adding treatment.

the original link given was from amazon and was $176
I'm not sure if those are the same models but yes that is a better suggestion in terms of price.. I was just stating that the original post that they linked to was for the $176 version, a better answer would have thus been your answer than to just go back and look at the previous post that was made in the same thread.

sorry dude if my post came over wrong - not my intention at all, just trying to help here - peace.

Here's a pict of my sound input and output settings.
Just to double-check, just now I did un-plug the mic from the MobilePre and then no sound was coming in, so the sound with these settings works correctly.
https://lh5.googleusercontent.com/_FqTNmgNQHz8/TVmnDDMDdGI/AAAAAAAAMNE/37siaa4QLQw/s1024/REWMacSoundPrefInOut.jpg

Well, just received my measurement and analysis gear, set it all up in their own carrying case, and I'm off to the races. Now I just need to learn how to really use this stuff ;D

Got the calibration stuff down I think, next step is to learn how to read the results, proper positioning and such. I've got Toole's book, so now it's studying time.

Here's the kit "in use" (but mic pulled over to the kit for the shot). Very rough shot :)

http://skeetersspot.smugmug.com/Electronics/Home-Theater/DSC00199/1191773851_Kqhuk-XL.jpg

Question.

When generating a signal for test, which surround mode should the receiver be on? I have a 7.1 setup but the test gear is connected via stereo hookups to the V.Aux input on the Denon (in my current setup).

Do I want ALL speakers involved in the test, or should I only have the 2 mains and LFE? If all what's the best way to do that?

Thanks!

Question.

When generating a signal for test, which surround mode should the receiver be on? I have a 7.1 setup but the test gear is connected via stereo hookups to the V.Aux input on the Denon (in my current setup).

Do I want ALL speakers involved in the test, or should I only have the 2 mains and LFE? If all what's the best way to do that?

Thanks!

You should measure only one speaker at a time, or a single channel + sub. When you send a mono test signal to more than one channel, you will get comb filtering (interference in the output). The input should be mono too.

You should measure only one speaker at a time, or a single channel + sub. When you send a mono test signal to more than one channel, you will get comb filtering (interference in the output). The input should be mono too.

Learning every day :)

So one speaker at a time (have to figure out how to do that from a mono signal). I guess you use a mode that outputs to all speakers but turn off all but one, then run the measurement for each speaker in succession? Is any particular mode setting on the receiver best?

Learning every day :)

So one speaker at a time (have to figure out how to do that from a mono signal). I guess you use a mode that outputs to all speakers but turn off all but one, then run the measurement for each speaker in succession? Is any particular mode setting on the receiver best?

Yup, that's the way you have to do it. :)

Try using 5 or 7 channel "stereo" and disconnecting all but one speaker. Or if you are using a separate amp, just run the one active channel to the amp input for the speaker you want to test.

Yup, that's the way you have to do it. :)

Try using 5 or 7 channel "stereo" and disconnecting all but one speaker. Or if you are using a separate amp, just run the one active channel to the amp input for the speaker you want to test.

Awesome, thanks for the tips. I'll play around and see how it goes.

Awesome, thanks for the tips. I'll play around and see how it goes.

Glad to help, and if you have any other questions once you get deeper into it, let me know. www.hometheatershack.com is also a great resource. They have a dedicated REW section that you can search through. More than likely, what you are going through other have before you.

Can anyone help me out with my sound card calibration readings? I used a Behringer UCA202 and my Radio Shack analog meter. My graph looks a little funky.

208905

Here's the measurement results as well :
208906

Hi Royce -

I've had my fair share of problems to solve when first trying to get REW to work for me, but I don't know what is causing the results you are getting. If you don't get your answer here, I suggest you post over on the www.hometheatershack.com forum.

2. Buy this calibrated microphone:

http://cross-spectrum.com/measurement/calibrated_behringer.html



OK, this is a ridiculously simple question (I hope)...I'm just starting to think about using REW, so all I'm doing right now is collecting the hardware I'll need for taking measurements down the road.

In the link above to buy the calibrated microphone, there are multiple versions with "extra" features. Which version is the suggested one to buy, Basic, or Premium+? Are the extra features necessary, or is 0 freq resp good enough for home theater measuring and calibration?

If you haven't noticed, audio calibration and theory is still a pretty weak link in my home theater chain. I plan on going through the forums here and over at hometheatershack to acclimate myself, but for now it would be great to at least start purchasing some necessary gear.

Basic is all you need but for $5 more just get the Basic+ so you have some flexibility. I like being able to point my mic up and not at the source for measurements.

The "Basic +" config is the one I recommend as well. Tip-up microphone orientation gives you a better read of the room. Tip-forward mic orientation is meant for capturing more of the direct sound from the speaker, such as for driver measurements.

Awesome, thanks for the quick replies guys!

In the link above to buy the calibrated microphone, there are multiple versions with "extra" features. Which version is the suggested one to buy, Basic, or Premium+? Are the extra features necessary, or is 0 freq resp good enough for home theater measuring and calibration? You really only need a calibrated mic if you intend to do full-range measurements. If you’re only interested in the subs, all you need is a Radio Shack SLM. The Shack has a calibration file for it.

For full range measurements, you really only need the “Basic” calibration, since accepted room-measurement protocol for free-field measurements calls for an on-axis mic orientation (more reading here (http://www.hometheatershack.com/forums/rew-forum/20293-full-range-eq-no-go-4.html#post184039) and here (http://www.hometheatershack.com/forums/rew-forum/28299-first-time-rew-plot-3.html#post263849)). However, like the others said, for another $5 the additional calibration of the “Basic +” is a no-brainer.

Regards,
Wayne A. Pflughaupt

I've read that the Cross-Spectrum guy actually suggests the best value is just to buy the Dayton EMM-6 directly, which does come with individual calibrations - though they are certainly not as trustworthy as the Cross-Spectrum one. I was trying to see how inexpensive a setup I could come up with (but more accurate and convenient for locating the mic than with the RS meter I already own) and for my purposes I'm quite sure it's good enough. If you somehow think you want better accuracy in the future, you can always send any of the mics for calibration separate from a purchase. It's not as cost-effective as buying a mic with calibration, of course, but it's a good way to get started step-wise.

RS meter + PC with line-in (or Behringer UCA202 for laptop) is definitely the least expensive way to get started. I personally went for an EMM-6 and the M-Audio MobilePre USB (the older model) refurb from eBay. The next step would be something like a Tascam US-122mkII or US-144mkII interface, and calibrated mic of any sort - though from reading the Cross-Spectrum FAQ, he seems to indicate that he thinks the EMM-6 is more stable than the Behringer due to the way the mic capsule is held in place.

Hi
My receiver doesn't have an aux input which other inputs which i plug it into?
This pic shows the other possible inputs:
http://users.tpg.com.au/f1mcmerc//inputs.png
also i dont have any other device eg. equalisers between the receiver and the subwoofer is that ok? the subwoofer has a parametric EQ on it's amp
thanks for any help can't wait to use room eq wizard!

Can anyone help me out with my sound card calibration readings? I used a Behringer UCA202 and my Radio Shack analog meter. My graph looks a little funky.

208905

Here's the measurement results as well :
208906

I use a UCA 202 as part of my acoustics measurement rig, but a RS SPL meter is a little rough for me as a primary critical measurement tool. It's fine for measuring peak SPLs and the like.

Instead I use a Rolls MP13 mic preamp and a Behringer ECM 8000 microphone. I picked up the idea of using them from one of the founders of the NHT speaker company.

Hi
My receiver doesn't have an aux input which other inputs which i plug it into?
This pic shows the other possible inputs:
http://users.tpg.com.au/f1mcmerc//inputs.png Any vacant analog input will work.


also i dont have any other device eg. equalisers between the receiver and the subwoofer is that ok? No problem!

Regards,
Wayne A. Pflughaupt

Is there any reason I can't use the microphone that came with my Yamaha receiver (YPAO) with Room EQ Wizard or are those calibrated just for use with the receiver?

Those mics aren’t actually “calibrated.” The calibration is in the specific receiver itself. So no, they aren’t suitable for use with REW. If they had a published frequency response you could create your own calibration file, but I’ve never seen one for a receiver mic.

Regards,
Wayne A. Pflughaupt

I'm looking at getting the REW and was wondering if anyone in San Jose, CA has one. I would like to see it in action and understand how it works before I buy all the stuff thanks.