First REW in room Measurements. How do they look?

[MediumRare]

I have the ability to play with the EQ in the ADI DAC so I'll have to try some tweaks and measure the response.

The only thing that bugs me about that is, in my use case, I like to leave the DAC in DSD Direct unless I'm listening to headphones. Which disables all EQ and tone control functions. I do this for the purity of the signal chain, and because I have a fairly large amount of digital music in both DSD and high rate PCM. I'll have to try it with the EQ and see. It may sound noticeably better to where I wouldn't want to listen without it.

My alternate route if not adding further bass trapping would be a subwoofer (or 2 but I'm short on space). I'd be interested to see what the FR curve would be running my speakers full range and implementing a rythmik sub perhaps out of phase with the speakers. Crossing the sub in around the second problem peak and running it down to 20Hz.

Check out Amir's review of your DAC - there is no possible way you will hear any degradation of sound quality - the improvement from the EQ should be very noticeable, indeed. Personally, I run my speakers full range and cross-over to my sub at 70 Hz (based on testing a range of options). Given you are rolling off at -6 dB around 35 to 40 Hz, you will hear a big difference from adding a sub and, depending on the music you prefer, it might be transformational.

There's absolutely no way to predict what phase setting for the sub will result in the smoothest crossover without nulls - you just have to try adjustments and test, then chose the one that's easiest to make a final fine EQ adjustment to polish the curve. Given the size of your room, it might be hard - or even impossible - to get down to 20 Hz, so no reason to get a giant sub nor to spend a fortune. You might find a good 10" or 12" sealed one under the chair by the window will do the trick to balance out the full range speakers below 100 Hz.

Regarding traps, and please don't be offended, IMHO you have gone off the deep end there and I don't see the benefit from them in your measurements beyond what good EQ could achieve anyway - so no need to add any more. Other folks are free (and welcome) to argue the other side of this question.

On the other hand you may experience significantly more precise imaging by moving your listening position forward a foot or so. I'd suggest trying sets of measurements 1 foot and 2 to 2.5 feet closer than you are now and seeing what the curves tell you. Also, be sure the coffee table is either covered with a heavy blanket or pushed closer to the speaker plane so it is essentially too close to reflect to your listening position.

Share what you learn!

 

[MetalDaze]

Check out Amir's review of your DAC - there is no possible way you will hear any degradation of sound quality - the improvement from the EQ should be very noticeable, indeed. Personally, I run my speakers full range and cross-over to my sub at 70 Hz (based on testing a range of options). Given you are rolling off at -6 dB around 35 to 40 Hz, you will hear a big difference from adding a sub and, depending on the music you prefer, it might be transformational.

There's absolutely no way to predict what phase setting for the sub will result in the smoothest crossover without nulls - you just have to try adjustments and test, then chose the one that's easiest to make a final fine EQ adjustment to polish the curve. Given the size of your room, it might be hard - or even impossible - to get down to 20 Hz, so no reason to get a giant sub nor to spend a fortune. You might find a good 10" or 12" sealed one under the chair by the window will do the trick to balance out the full range speakers below 100 Hz.

This is exactly what I have been telling myself. From both the review here and the manual which states the way in which they implemented their design results in a transparent conversion to PCM.

That spot is also precisely where I was thinking of starting my 'sub crawl'. Though I'm fairly sure that's where it will go. My previous room was 20' x 11'. I miss the acoustics in there. I don't know if the dimensions of my room will allow such long wavelengths. The fundamental is around the first node we see in the waterfall. I mentioned earlier an F12 subwoofer but I meant to say L12. I think that 12" sealed servo sub will do a lot once it's properly dialed in.

Regarding traps, and please don't be offended, IMHO you have gone off the deep end there and I don't see the benefit from them in your measurements beyond what good EQ could achieve anyway - so no need to add any more. Other folks are free (and welcome) to argue the other side of this question.

On the other hand you may experience significantly more precise imaging by moving your listening position forward a foot or so. I'd suggest trying sets of measurements 1 foot and 2 to 2.5 feet closer than you are now and seeing what the curves tell you. Also, be sure the coffee table is either covered with a heavy blanket or pushed closer to the speaker plane so it is essentially too close to reflect to your listening position.

Share what you learn!

I have thick skin. No offense taken. Teetering off the deep end is where I live most of my days anyway But In my defense the room sounded awful. Absolute garbage even with furniture, before treatments. I had some of the acoustic foam and a drop ceiling prior to a renovation which sounded okay. I used the calculators on GIK's website to get a rough idea of what I'd need to get the in room response I was hoping for. I didn't use any of their experts though. That probably could've shown me in some better light how to approach.

I will certainly look further into it and play with my listening spot. I took measurements where I normally critically listen. But also towards the back wall as if leaning back on the couch, relaxed listening. Of course there's more of a node in that region.
I think I'm roughly as close as I want to be given the size of the speakers, but the room continues to be the glass ceiling. Oh well, I will move to a house eventually, and by god these speakers are coming with me!

Thank you and everyone for your wisdom. I'll continue to update as I make tweaks and find things that work.

Further comments and input is always welcome. Cheers!

 

[Hipper]

Thanks for posting your graphs - that's helpful.

They're much better then I thought - better then mine in fact before EQ.

EQ might be able to solve most of your issues. The general guidelines to EQ are to lower the peaks but be careful with filling in the dips. The reason for this is twofold: filling in dips by large amounts will increase the strain on your drivers, and sometimes these dips are actually not 'fillable' because of the nature of them - they are caused by positioning factors. To fill in the big dip at 50Hz on my graph with EQ I used a 10db increase but reduced the overall gain (the gain of all the frequencies) by 9dB. Somehow for reasons I don't understand it worked. Very narrow dips may not be audible (your one at 160Hz perhaps). If they aren't there's no need to worry about them. There's a useful free downloadable set of test tones that can help here:

https://realtraps.com/test-cd.htm

I used this once I had done all my EQing to actually hear what's going on.

Whilst a nice flat graph looks impressive it is what it sounds like to you that counts. 'Smooth' seems to be the key word rather then flat.

Regarding your DAC and its EQ, I use a Behringer DEQ2496 and quite a few people say it's noisy or it damages transients etc.. Well firstly, I never heard this damage even with out it doing any work, and with it applying EQ the improvements must surely overwhelm any possible damage. I wouldn't be without it!

I notice you have a lot of ceiling panels. Ceiling reflections are very much dependent on the dispersion pattern of your speakers. Mine are ribbons and disperse in a narrow angle vertically and as a result I don't get much in the way of ceiling reflections, especially as I use The Thirds for positioning. It's also possible you get reflections off that coffee table.

 

[MetalDaze]

Thanks for posting your graphs - that's helpful.

They're much better then I thought - better then mine in fact before EQ.

EQ might be able to solve most of your issues. The general guidelines to EQ are to lower the peaks but be careful with filling in the dips. The reason for this is twofold: filling in dips by large amounts will increase the strain on your drivers, and sometimes these dips are actually not 'fillable' because of the nature of them - they are caused by positioning factors. To fill in the big dip at 50Hz on my graph with EQ I used a 10db increase but reduced the overall gain (the gain of all the frequencies) by 9dB. Somehow for reasons I don't understand it worked. Very narrow dips may not be audible (your one at 160Hz perhaps). If they aren't there's no need to worry about them. There's a useful free downloadable set of test tones that can help here:

https://realtraps.com/test-cd.htm

I used this once I had done all my EQing to actually hear what's going on.

Whilst a nice flat graph looks impressive it is what it sounds like to you that counts. 'Smooth' seems to be the key word rather then flat.

Regarding your DAC and its EQ, I use a Behringer DEQ2496 and quite a few people say it's noisy or it damages transients etc.. Well firstly, I never heard this damage even with out it doing any work, and with it applying EQ the improvements must surely overwhelm any possible damage. I wouldn't be without it!

I notice you have a lot of ceiling panels. Ceiling reflections are very much dependent on the dispersion pattern of your speakers. Mine are ribbons and disperse in a narrow angle vertically and as a result I don't get much in the way of ceiling reflections, especially as I use The Thirds for positioning. It's also possible you get reflections off that coffee table.

No problem. Thank you for taking the time and looking them over. I'm happy to know things are looking good.

Great minds! I like that website. I've read Ethan's articles on acoustics and watched his tutorials on youtube as well. I haven't looked into his test tones so I will do that. Another website I like which has similar tools is:

https://amcoustics.com/tools/amroc?l=14&w=11.5&h=8.5&ft=true&re=DIN 18041 - Music

I like to look at the peaks/nodes on my measurements. And then find the corresponding frequency on this web page. It shows you a 3D graphic in real time of where the standing waves propagate in the room. This helps me better understand where to attempt physical changes in accordance with the physics happening. I guess I'm a visual learner.

The EQ so far seems to be my quickest and cheapest bet since I already have the DAC. But I never considered the reflections off the coffee table as yourself and another poster pointed out. Something else to consider

I have treatments on the ceiling because my bookshelf speakers had a pretty harsh speaker boundary reflection from the high tweeter. That's where the smaller darker panels came in. And the mirror trick. The speakers I'm using now have 3 drivers on top firing upwards in a 'semi omnidirectional' fashion. So I use the other ceiling panels over the speakers to quell the first reflections there and help keep the soundstage intelligible and cohesive to the center image.

 

[ernestcarl]

I do this for the purity of the signal chain...

I understand the sentiment, but... the effect from your room and speakers do so much to colour the sound already. Purity of the signal chain in that context is practically ineffectual, IMO.

 

[MetalDaze]

I understand the sentiment, but... the effect from your room and speakers do so much to colour the sound already. Purity of the signal chain in that context is practically ineffectual, IMO.

Once I have the time to make some adjustments, the post EQ measurements should show me the way.

I agree that the speakers and room color the sound quite a lot. My normal approach is fix everything I can physically. But even then, only use EQ/DSP as a last resort. There's a couple of spots in the room where my budget bit the bullet and I made some sacrifices for the time being. I may be able to knock down those node peaks with a 2 or 3 more carefully placed traps in spots I said at the time "I'll fill in later" (but haven't ). We'll see.

Now that I have the mic and program, I'll be keeping to the phrase 'measure twice, cut once!'

 

[MetalDaze]

Back with a quick update. Decisions were made & I opted for a Rythmik L12 subwoofer before further iterations of acoustical improvements. Not unlike our forum host I myself am a bit of a bass head I have to say my experience getting the sub was flawless. I wish I could've gone dual, but perhaps in the future. I'm glad I waited until after things were back in stock from the holiday rush. From payment to delivery the process took 3 days to the hour! I live in the north east so coming from Texas this was a nice surprise. Especially with shipping included in the price.

The sub feels really solid. Very nice clean look about it and weighs a lot for it's size. Which is very compact given it houses a 12'' woofer and puts out incredibly deep low end. I was surprised to feel how soft the woofer surround is looking at it's size. I expected it to be about as stiff as the side wall of a tire. But it was much softer. That of a bicycle tire on a rim, without any air in it. The woofer meanwhile, feels like it's floating in a container of viscous fluid like silicone. Very firm to the touch with a strong restoring force. All a product of design around the servo system. Very cool, and I'm very happy with it. I got mine in Black Oak since all my speakers have real Oak or Walnut veneers on them. You can tell its a wrap. Though there's nothing about it that lacks. It's actually quite a bit more subwoofer than I expected all together for the cost. 100% would recommend.

After setting it up and playing it in by ear a bit, I took out the mic and stand and made some measurements. There are measurements I've taken but haven't posted which reveal speaker boundary interface cancellations (large crevasse in measurement which can't be EQ'd). They are a product of my room dimensions and where I have the speakers set up. This is also reflected somewhat in the posted measurements where the peaks & nulls can be seen in the low frequencies- and up through the spectrum in a periodic trend.

All this is to say further study is needed The treated room response sounds pretty good as is, and I was missing that lowest octave for music and movies more. I did my best with the PEQ on the Rythmik and tried a few different tweaks using the RME. But none of what I applied really made any significant difference in my measurements. I believe this is because the dominant concerns are now in the bass and sub bass regions which are modal. And best attacked from the physical realm (this isn't always feasible).

Here is a measurement I took which shows the speakers by themselves, the speakers with the sub, and just the sub. As you can see, some significant shelving occurs when looking at only the subwoofer before shooting back up at 80Hz. Thankfully the positioning of my main L and R speakers conforms with the Harmon study of subwoofer placement. So I 'technically' have 3 subwoofers along the front wall, which help offset this response upset. I also ran the sub a little too hot in this measurement which resulted in a heightened SPL. I have since dialed the sub back 2 notches which blended it seamlessly. I followed Rythmik's recommended setting with PEQ off since the distance from the mains is almost negligible. The delay set for front ported speakers (~10 O'clock position), crossed at ~100Hz.

In comparison to the prior waterfall graph for the L+R, the ringing at 46Hz has been reduced significantly while remaining in the time domain of quick decay. Complementary waves result in slightly higher peaks than previously. There also has been a shift to an increase in sub bass energy. I assume where other energy is now being transferred. Switching to Low HT and 12dB roll of did not affect this in any measurable way. It should be said though that these tones are below the threshold of audibility. Maybe can be felt.

That's all for now. Time for a drink!

Cheers

 

[MediumRare]

Great start. Where did you end up placing the sub? Have you implemented a crossover and roll off setting for it?

 

[MetalDaze]

Great start. Where did you end up placing the sub? Have you implemented a crossover and roll off setting for it?

Thanks! I wound up placing the sub left justified between the speakers. The main L and R are along the 'front' short wall. Closer to the corner there was just too much excitation in the room. Leaning the sound more towards "one note bass". I found the spot between the speakers, closest to the left gave the smoothest sound. Right between them in the middle of the wall was okay, but it didn't seem to have as much impact.

I set the crossover on the Rythmik to come in @ ~100Hz. By design, the main L & R speakers send 100Hz and down to their 12" woofers also. I use the Low Music setting at 24dB slope for 2 channel. And flip it to Low HT 12dB roll off when I'm playing games or watching movies. I use the latter when listening to vinyl too. According to Rythmik this implements the equivalent of a rumble filter so you avoid non linearities in cone movement from surface noise, pops etc.

*Edit- I guess I should add my P5 Preamp has analog bass management and tone controls. Along with an independent subwoofer level. I run the mains as Full Range and also have the subwoofer cross over on the P5 set to off. This means the summed L+R channel get sent full range to the sub. And I let the subwoofers internal crossover to the work. Now that I have the levels, cross over and delay set. If I want more low end all I have to do is turn up the subwoofer level knob on the P5.

For anything other than 2 channel music, I use my Integra DRX-3 and Home Theater Bypass on the pre amp. In the Integra all the distances to speakers and sub have been set by me via laser. The levels have also been balanced by me with an SPL APP. I run my mains and surrounds full range (except for the center channel, when I use it). I have to use 'Double Bass' set to 'on' in the receiver since 98% of the time I leave it in direct mode (don't DAC and then ADC my sh*t!). So even when a signal source has the .1 the receiver doesn't always send the signal to the sub because it's in direct mode with the speakers set to Full Range or Large. This is just my personal work around. Then finally I let the subwoofer do any further crossing etc according to the settings on the plate amp. There is a subwoofer level control on the Integra which is accessible via the remote and visible through the OSD.

 

[MediumRare]

So let's see your REW measurement of the full system with the crossover implemented!

 

[MetalDaze]

Here we are:

I applied 1/6 octave smoothing to see things a bit more clearly. 1/12 was about the same with more jagged edges.
The peaks at 46Hz and 105Hz got intensified here, but I lowered the subwoofer volume a couple of notches since and this helped normalize the peaks a bit. Still more absorption is likely needed (barring EQ) to flatten them out.

I saw it before. But I'm noticing it more now that I'm looking at it again in comparison - the shelving between 100Hz & 300Hz seems to have grown deeper. More so than I thought on first look. Maybe if I keep the roll of setting at 24db but dial the crossover back to between 40 & 60Hz it may help smooth this over? Only one way to find out I suppose!

 

[MetalDaze]

Scratch that about the dip. I was looking at a different graph. The dip between 100 and 300Hz is still the same.
Here is a comparison of the original measurement I took, vs full range with the subwoofer. 1/6 smoothing target @ 75dB.

 

[MediumRare]

Will you be trying the EQ?

 

[MetalDaze]

Will you be trying the EQ?

Yeah using the RME is the next step. I tried different settings on the Rythmik but it made little difference in the measurements. Now that I have the sub in it's happy place and base line data gathered I'll see what I can make happen with the PEQ in the DAC. I played with it a bit but didn't save any presets since I wasn't happy with it yet and ran out of time. I need to pinpoint precise frequencies in REW and write them down to adjust them in the DAC, with the proper Q value. It'll take some trial and error.

I will post back with the results once it's something I can be happy with

 

[MediumRare]

. I need to pinpoint precise frequencies in REW and write them down to adjust them in the DAC, with the proper Q value. It'll take some trial and error.

I will post back with the results once it's something I can be happy with

Have you tried the function in REW that creates the filters for you? I've found it saves about 75% of the time, then you check the actual outcome in REW and tweak by ear as well, listening to a wide range of music - the few remaining harsh spots will jump out once the filters remove the glare and lumps.

 

[MetalDaze]

Have you tried the function in REW that creates the filters for you? I've found it saves about 75% of the time, then you check the actual outcome in REW and tweak by ear as well, listening to a wide range of music - the few remaining harsh spots will jump out once the filters remove the glare and lumps.

I have not. I wasn't aware that was a function that could be performed in REW. Great tip! That's what I'll be doing with my free time today.

 

[MetalDaze]

I was able to transpose the EQ filter settings from REW to the RME. There are only 4 locations you may apply EQ per each preset in the DAC. Luckily my problem areas were in 4 bass frequencies regions. 46Hz, 105Hz, 220Hz and 300Hz. So those were the areas I focused on in a preset I labeled 'House".

Here is a measurement I just took comparing the Pre and Post RME EQ. Target 75dB, 40 to 95dB Y-Axis, 15 - 500Hz X-Axis.

I Applied -3.0 and -4.0dB respectively for the first two peaks. The valleys at 220 and 300Hz needed more of a boost so I applied +5dB and +7dB to those. Those values are higher than I would have liked to apply, but there was not enough of a measured difference using ~+3dB.

I haven't touched anything above 500Hz so the rest of the FR graph looks about the same. But in the bass region it certainly measures smoother.

 

[MediumRare]

I was able to transpose the EQ filter settings from REW to the RME. ...

I haven't touched anything above 500Hz so the rest of the FR graph looks about the same. But in the bass region it certainly measures smoother.

How does it sound? Are you able to play with the Q so you don't drop anything below, say 40 Hz?

 

[MetalDaze]

How does it sound?

In a word.. it sounds different. I spent some time listening to a multitude of genres after enabling the EQ preset. There is definitely a decrease in bass output. I wouldn't say it is being better controlled, just less of it. In my use case this is to be expected. The trade off is where I added gain to the 220-300Hz trough. The extra boost here is noticeable through my mid woofer (~100Hz - 1700Hz). Mostly in male vocals, but in some other types of music like Jazz or soft rock, there is a greater sense of low level detail retrieval.

Admittedly, I ran this through with my entire music library (Redbook, High Res PCM and DSD). Although I could tell the difference between having the PEQ being enabled or not, I could not tell the difference having everything being converted to PCM (without EQ enabled). I only listening on my speakers, I haven't tried this using headphones.

So in my case, Room Correction > Native Mode.

And I suppose while I'm being honest, but risk being exiled I'll let the cat out of the bag.
I sort of prefer the sound of my system without the EQ...?

With EQ enabled I can say I believe it's more accurate. Without EQ, although there are some ups and downs in the low end room response. It sounds more "lively" (but less accurate). This is probably leaning into the gray territory of pleasurable 2nd harmonic distortion. I also have been listening to my system this way for years, and my brain needs more time to 'break in' to the corrected room response.

A nice feature of the RME is I can turn on/off the EQ via the remote. So I can quite literally engage the EQ on the fly and listen for the change in sound, which helps my brain get over any confirmation biases I may have.

Are you able to play with the Q so you don't drop anything below, say 40 Hz?

Yes! I read making changes below 35 or 40Hz is something to be avoided. In the PEQ of the ADI-2 you are able to change the shape of the Q function. I chose the last example (it looks like a shield volcano cross section), which provides the most narrow bandwidth. I then further manipulated the magnitude of the Q value, to narrow the area of interest corresponding to the FR curve.

 

[MediumRare]

In a word.. it sounds different. I spent some time listening to a multitude of genres after enabling the EQ preset. There is definitely a decrease in bass output. I wouldn't say it is being better controlled, just less of it. In my use case this is to be expected.
...
And I suppose while I'm being honest, but risk being exiled I'll let the cat out of the bag.
I sort of prefer the sound of my system without the EQ...?

With EQ enabled I can say I believe it's more accurate. Without EQ, although there are some ups and downs in the low end room response. It sounds more "lively" (but less accurate). This is probably leaning into the gray territory of pleasurable 2nd harmonic distortion. I also have been listening to my system this way for years, and my brain needs more time to 'break in' to the corrected room response.

A nice feature of the RME is I can turn on/off the EQ via the remote. So I can quite literally engage the EQ on the fly and listen for the change in sound, which helps my brain get over any confirmation biases I may have.



Yes! I read making changes below 35 or 40Hz is something to be avoided. In the PEQ of the ADI-2 you are able to change the shape of the Q function. I chose the last example (it looks like a shield volcano cross section), which provides the most narrow bandwidth. I then further manipulated the magnitude of the Q value, to narrow the area of interest corresponding to the FR curve.

Don’t give up now, you’re just getting started. Less bass is unacceptable! Keep at it.