# RoomEQ help



## Moez (Nov 29, 2006)

I've spent 3 days trying to get my computer hooked up with Room EQ without any success at all. Tried connecting my creative soundcard Live! without any success at all. I'm seeing that a manual approach is being offered on both BVD and using the TAMREQ wizard. I guess i'm not the only person having a tough time getting the soundcard connected with the RoomEQ software. I'd rather use the RoomEQ or RS +D which I am licensed than doing it manually. Can you help me get this soundcard of mine acknowledged by RoomEQ?...Thanksraying:


----------



## brucek (Apr 11, 2006)

You'll have to expand on the problem a bit further.

As a start can you post a picture of REW like the one below.

I removed your restrictions on posting pics.....

I also want you to read this thread









brucek


----------



## Moez (Nov 29, 2006)

Thanks Brucek...I actually figured out how to do it manually and exported my measurements to RoomEQ...so far it's worked out pretty well. Still do each channel at a time which is taking some time but I do have a few of questions. 
1) I have two subs stacked in a corner behind my sofa which is 4 feet from my back wall. I literally can hear them behind and to my right when a movie calls for a lot of bass. For the room I have (18'X13') I'm limited to where I can place them but shouldn't i have them placed where I can't tell where the bass is coming from? 
2) I own a B&W HTM center speaker and I'd like to know if it is considered bass limited with these specs: Freq. Response 49Hz - 23kHz ± 2dB on reference axis 
Freq. Range -6dB at 35Hz and 50kHz, -3dB at 42Hz and 42kHz 
3) I'm using B&W 802N's for right & left speakers and believe they should be listed as full range but I'm confused at what limit to set the crossover at 40,60,80? Should I do this in my AV32r_DP or on the subs? (Velodyne HGS15,& HGS-18) I'm knew at this and find more questions than answers. Thanks.


----------



## DrWho (Sep 27, 2006)

I find that subs generally sound better (less localizeable) when positioned in the front of the room. If the subs can't move, then your best bet is to lower the crossover going to them. But if you listen at moderate to loud volumes, then the harmonic distortion on the subs is going to be all too noticeable (meaning that you'll never be able to achieve no localization).

Btw, even though your mains are full-range, you should still set every speaker to small. Any overlap is going to cause peaks in the frequency response. And usually it sounds more natural when the crossover point is the same for every speaker too.

I would start by setting everything to small with an 80Hz crossover and then lowering the crossover until you don't notice the subs anymore. Do not use the crossovers on your subs (basically set them as high as they will go). I don't mention this as the end all be all for every situation, but it's a start.


----------



## Moez (Nov 29, 2006)

Hello Mike,
I took your advice and moved the subs to the front of the room,each one next to my center speaker and slightly behind each front speaker. It sounds soooo much better...now I can't tell where the bass is coming from. I shut off the crossovers on the subs and set the crossover to 80 in the AV-DP to start. I'll have to EQ the fronts and subs in their new locations but it will definetely worth it...thanks!!! I also wanted to mention something I noticed last time I EQ'd my speakers. First I set up the RS mic at my seating position and I set up my computer and monitor between me and the mic (don't own a laptop). Because of the problem I'm having with my soundcard I'm measuring manually. I noticed that my position next to the mic had an influence on the mic reading. If I moved back or forward a few inches the reading would change a few DB's . I can see why having the Roomeq do the work automatically is the way to go...otherwise I'm not sure if doing it manually is so accurate...what do you think?


----------



## brucek (Apr 11, 2006)

> I can see why having the Roomeq do the work automatically is the way to go...otherwise I'm not sure if doing it manually is so accurate...what do you think?


Using REW sweeps is much more accurate than measuring manually....

brucek


----------



## DrWho (Sep 27, 2006)

Moving the mic around will also yield small (sometimes huge) changes in the response


----------



## Moez (Nov 29, 2006)

So is there an advantage to moving it around near my seating position?


----------



## brucek (Apr 11, 2006)

> So is there an advantage to moving it around near my seating position?


If you find by quick experimentation that there is a large response change for different seating positions, and you want to be nice to those people sitting in those other positions, then you can take several readings and create an average filter setting in the equalizer to compromise for a decent response across the board. There is a measurement averaging feature in REW...

Then you can also have a critical listening set of filters just for you and the prime seat..... 

brucek


----------



## muse77 (Dec 14, 2006)

Great advice on moving the mic around. I imagine that as a person adds room treatment they will want to move the mic around to the various positions to monitor changes there too.


Walking the mile to audio bliss takes a step at a time.


Bryan


----------



## Moez (Nov 29, 2006)

Is it possible to check my soundcard with ROOMEQ software without connecting to a mic or AV? I'm sure the problem is in the mixer but as my PC is away from my theater room I'd like to test the soundcard with the software remotely if possible. Also I do have a digital output on this card which I'm not sure would change anything. I've not connected anything to that output before.


----------



## muse77 (Dec 14, 2006)

Part of the calibration of RoomEQ is to hook the output of the sound card back around to an input on it. You might try part of the calibration procedure to check your card. 

I have a Sound Blaster Audigy and I use the Fiber Optic output from it into my AV unit and it works fine.


----------



## brucek (Apr 11, 2006)

> I have a Sound Blaster Audigy and I use the Fiber Optic output from it into my AV unit and it works fine.


You do realize that when you use the digital output that you can't calibrate out a soundcards response anomolies?

brucek


----------



## muse77 (Dec 14, 2006)

I didn't know that. But when I started calibration I realized I couldn't input to both channels. So I have been using the pc speaker output for doing calibration and testing room. 

Would it be best to avoid the digital output while testing the room?

I think I misunderstood what Moe was saying. I thought he was wanting to use digital out for normal use.


----------



## brucek (Apr 11, 2006)

> Would it be best to avoid the digital output while testing the room?


For testing with REW, we want to eliminate the poor frequency response of a soundcard. Some cards are quite poor at low frequencies. 

To accomplish this, a calibration file is created using the *analog* line-out connected directly to the *analog* line-in. When both these ports are used in the testing, then the file created corrects the response graph to simulate a perfect soundcard. This isn't the case when you use the digital output.



> I think I misunderstood what Moe was saying. I thought he was wanting to use digital out for normal use.


I think he just wanted to see if his soundcard was compatable and usable with REW. Your answer was quite correct. To find out he should do a soundcard calibration. If that works, he's gold.... just don't use the digital output.

brucek


----------



## muse77 (Dec 14, 2006)

Thanks for the info. I make enough mistakes without creating more headaches.

_To walk a mile takes one step at a time._
Bryan


----------



## DrWho (Sep 27, 2006)

I use the digital output :innocent: 

To calibrate, I can run the analog preouts from the receiver back to the soundcard...only problem is it assumes a flat response inside the receiver.


----------



## brucek (Apr 11, 2006)

> To calibrate, I can run the analog preouts from the receiver back to the soundcard


Since the analog output circuits of the receiver won't be used when using REW to take a measurement, this probably wouldn't be a good idea. Best to use the analog line-in and line-out...

brucek


----------



## Moez (Nov 29, 2006)

I finally got the soundcard calibrated with the software. Ineeded to select stereo mix and not line in to make that connection. Now another problem but I'm feeling like I'm that close to taking measurements successfully. I have set the measurement level, input volume control, and calibrated the soundcard. When I started to take measurements I set the target level and did an automatic measurement . I heard the sweep through my left speaker which I am trying to measure but all I'm getting is a flat response line....very similar to the soundcard measurement on the graph....I also got the same response when I measured the sub...any idea why this is happening?


----------



## JohnM (Apr 11, 2006)

Hi Moe,

Stereo Mix is an internal loopback within the soundcard, it does not connect externally. You have to use Line In and configure the soundcard to get Line In working, then all should be OK for measurements. Please post a screenshot of the Creative mixer (will be in the Program files -> Creative program group somewhere) so we can try and figure out which setting needs to be changed.


----------



## Moez (Nov 29, 2006)

OK...this iis a spashot of my volume control record and playback


----------



## Moez (Nov 29, 2006)

I got it to work with changing the input from right to left.....finally! Now that I can take measurements I'll have to focus on understanding how to read the measurements...especially when measuring my sub. the target curve for my sub and left speaker so far seem way off...I'll keep on keeping on...


----------



## Moez (Nov 29, 2006)

Spent last evening Eq'ing all my speakers but wanted to know why the measurment of the channels came 10db average under the target line? Also when integrating my bass limited speakers which I have set them all to bass limited (not really sure why) am I measuring each of them with the subs on? Once I have completed all speakers do I eliminate the filters for the sub? Not sure why I would have filters for the sub only when I'm using the subs with all my speakers at the same time.


----------



## JohnM (Apr 11, 2006)

You are in a different position to most on here Moe as you have full range EQ capability for all channels in your processor. Measure the sub first on its own, then set up filters to correct its response and leave those filters in place for your subsequent measurements. For the main speakers measure a speaker on its own, then measure it together with the sub and see which of the peaks in the speaker-alone measurement are still present when measuring speaker+sub. Only apply filters to the peaks you can see in both measurements.

For the target level, did you use the Set Target Level process?


----------



## Moez (Nov 29, 2006)

Before I do a sweep of the speaker I'm measuring I always set the target level first. I also wanted to know where I should set the subwoofer volume to on each sub...even though I calibrate it to 75db I'm sure it makes a difference. Also where should I set the susonic filter? (15Hz-35Hz) Also does high pass crossover have an impact ...I have the crossover set at 120(max) and set it in the AV-DP. John do i setup my B&W 802's as bass limited or full range? I've heard that setting all the speakers as bass limited is the way to go...how do I know which is correct and what to set the crossover at for the mains?


----------



## JohnM (Apr 11, 2006)

The subwoofer volume alters where the gain trim for the sub ends up when you calibrate, as the higher the volume the more the processor has to reduce the gain of the output signal to get back to the desired level. Best thing is to set the processor sub trim to 0dB, then adjust the sub volume control to get 75dB from the sub calibration signal. 

For maximum low frequency extension turn the subsonic filter off. 

If the sub's high pass cannot be defeated then leave it set as high as it goes. 

Running speakers as bass limited reduces their distortion by reducing cone excursion and even modest subwoofers have better LF than good speakers, however your 802's have very good low frequency extension and you may find they sound better set as full range, that also removes the problem of getting them to integrate well with the sub as the best crossover setting for one speaker may not be the best for the other. Try running them full range and bass limited and see what you like best. If you do run them bass limited then you can experiment with crossover settings from 80Hz downwards to see which setting gives you the smoothest response before you apply any EQ.


----------



## Moez (Nov 29, 2006)

thanks for the advice John ..I'll check these ideas out...also wanted to ask you if changing the phase on a speaker is ok if it gets a better result in the measurement? Also wanted to know if I should use my centre which is an B&W HTM as full range or bass limited?


----------



## JohnM (Apr 11, 2006)

Don't change the phase on the main speakers, but changing phase on the sub(s) is OK. The centre speaker should be set as bass limited.


----------



## Moez (Nov 29, 2006)

my left main only out of phase looked soooo much better , flatter, but if you think it's not a good idea I'll switch it back....the problem with my setup in the front is right main is less than a meter from the sidewall and my left is two meters away


----------



## brucek (Apr 11, 2006)

> my left main only out of phase looked soooo much better


You'll kill your soundstage if you put them out of phase............

brucek


----------



## Moez (Nov 29, 2006)

John is it OK if I put my center out of phase? It just sounds so much better that way...also flatter resonse on EQ.


----------



## JohnM (Apr 11, 2006)

If it sounds better, then that can't be a bad thing  but keep an ear out for odd effects as things pan across the soundstage from side to side. I guess you have tried inverting the phase of the subs?


----------



## Moez (Nov 29, 2006)

I did and that worked out great....thanks.


----------



## Moez (Nov 29, 2006)

John do you have any good places to look for info on treating the room? I've got some canyons/nulls on these measurements I'd like to address if I could. I've noticed that when I play a constant frequency that I'm seeing as a big null and crawl around the room and see where it's the most quiet, what am I to do to treat it? Just wondering how much control I have over it?


----------



## JohnM (Apr 11, 2006)

Try here: http://www.realtraps.com/


----------



## DrWho (Sep 27, 2006)

Just a few more you might consider:
http://www.ethanwiner.com/acoustics.html
http://forums.klipsch.com/forums/thread/796165.aspx
http://www.acoustics101.com/default.asp
http://www.prosoundweb.com/install/sac/sup27/part1/mesp2.shtml
http://www.prosoundweb.com/install/sac/sup27/part2/ppam.php

Never hurts to have too much info


----------



## Moez (Nov 29, 2006)

thanks Mike..


----------



## Moez (Nov 29, 2006)

Hi John, I'm posting a measurement of my two subs...I think it looks pretty good but when I take a measurement of my subs along with the left front speaker(set as bass limited) I get a measure,ent that looks like the second post. I've set the crossover in the AV at 80...any idea why it's so much higher than the keft speaker?


----------



## JohnM (Apr 11, 2006)

Do you mean why is the bass higher in the measurement with left+subs than with left alone? That's because the bass management filters for a main speaker only roll off at 12dB/octave (i.e. with the crossover at 80Hz, the level at 40Hz will be 12dB lower than without a crossover and at 20Hz it will be 24dB lower). Your speakers have very good bass extension so even with the crossover filter in place there is still significant low frequency output which adds to that produced by the subs. What does the left speaker measurement alone look like, when run as full range?


----------



## Moez (Nov 29, 2006)

This is the left speaker at full range....that's a **** of a null at 60hz


----------



## JohnM (Apr 11, 2006)

That certainly is quite a dip, worth seeing whether it is still there if you test both left and right speakers playing at the same time. Also try measuring with the mic a foot or two to either side and forwards and backwards of the listening position to see how localised that dip is. The speaker does have a LOT of low frequency output though, they really don't need any help from a sub at the bottom end.


----------



## Moez (Nov 29, 2006)

This may be a dumb question John but how do I test both left and right at the same time. Do I chose either left or right in RoomEQ? I know the sub works with either left or right when I chose it as bass limited but not sure how to test both fronts at the same time...Oh I will try moving the mic around...great idea since I can move my sofa around to work...thanks.


----------



## brucek (Apr 11, 2006)

> Do I chose either left or right in RoomEQ?


Those are simply convenient tabs in REW. The program outputs an analog mono signal on one channel from your computer. Any speaker selection must be done at the receiver itself.

If you want to test your main speakers, simply turn them on with the sub..

brucek


----------



## DrWho (Sep 27, 2006)

Hey Moez, I think a lot of what you're seeing is the result of changing the scales of the graphs...your sub and left+sub are both essentially 84dB peak throughout the band below the crossover region. And the output at 60Hz hasn't changed either. The peak at 24Hz makes sense in light of the huge peak of the left speaker.

Did the mic move at all between the different measurements? Even as much as an inch inadvertantly?

It looks to me like you've got some destructive interference in the 55-90Hz region which has led you to boosting the output of the subwoofer for a flatter crossover transition. Did you smooth the graphs? Unsmoothed is more informative.

Anyways, try dropping the output of your sub 12dB (for when measuring just the left + subs) and then take some more measurements (and keep it unsmoothed). You should notice much more dramatic dips in the crossover region. When you've got both mains playing, you should probably drop the subwoofer 6dB (since there should be a 6dB rise in the higher frequencies compared to just the left main).


----------



## Moez (Nov 29, 2006)

Hey Mike.....are you familiar with the MATT TEST (musical articulation test tones)? I have the test tones to try in my system but was wondering if could analyze the result?


----------

