REW

Conrad.

Moderator
If you unscrew the umik 1 there are some dip switches that adjust the sensitivity of the mic: Massively clipped UMIK-1

And you need to make sure you have the latest cal file as I believe they recently realised that there was a miscalculation in all their old file and the sensitivities were all about 6dB down or something. If it's new then I guess you just downloaded the file in which case it'll be the right version.

Interesting comparison.

You know REW has an RTA in it too?
 

tebbo65

Active Member
If you unscrew the umik 1 there are some dip switches that adjust the sensitivity of the mic: Massively clipped UMIK-1

And you need to make sure you have the latest cal file as I believe they recently realised that there was a miscalculation in all their old file and the sensitivities were all about 6dB down or something. If it's new then I guess you just downloaded the file in which case it'll be the right version.

Interesting comparison.

You know REW has an RTA in it too?
Sh*t the bed! I'm not messing with those dip switches but very interesting!
Cal files downloaded a couple of hours ago so should be the right versions?
Yes I know REW has RTA so will get into it, thanks. The XTZ version is so simple and good for initial, rudimentary analysis.
download.jpg
 

tebbo65

Active Member
If you unscrew the umik 1 there are some dip switches that adjust the sensitivity of the mic: Massively clipped UMIK-1

And you need to make sure you have the latest cal file as I believe they recently realised that there was a miscalculation in all their old file and the sensitivities were all about 6dB down or something. If it's new then I guess you just downloaded the file in which case it'll be the right version.

Interesting comparison.

You know REW has an RTA in it too?
After thoroughly reading the linked thread you kindly posted I am hoping the issues have been resolved as it was a rather old post started the back end of 2014? I notice they also changed the mic's sensitivity from 12dB to 18dB so maybe that was addressing the issue? Although confident at opening stuff up and doing minor repairs I am a bit reluctant to start melting seals on a brand new bit of kit to get inside. I did also notice that the clipping issue was at very high SPL levels so I think I'll leave alone unless I do get clipping issues

On a different subject. Do you/should I use 'acoustic reference timing' when taking measurements? I sort of get why it is used but really wondered if it is the norm to engage it?

Thank you.
 

Conrad.

Moderator
There's three things here:
  • the ability to change an Umik's sensitivity, which is the thread I linked. That's still the case and isn't an issue, it just allows you to change it's profile to suit your needs and levels.
  • the incorrectness of the cal files. That's been resolved and new cal files have been published. It's completely different from the dip switches though, sorry if I confused things.
  • issues with the Umik-2, which I believe are resolved now as well. I'm still not sure that there's much need to upgrade.

Completely agree about not wanting to touch the umik. If it works, don't break it!

Yes, you should use acoustic timing references. Basically it plays a little blip (the timing reference) from the chosen speaker before taking a measurement. With that REW has a fixed reference that it can align all measured responses to so things like the speaker delays and the alignment tool work correctly. Without it REW isn't able to line up different measurements accurately. You won't always need it but it's a good habit to be in. Guaranteed the time you want it you won't have it of you're not in the habit.

The difficulty is usually around being able to measure subs on a mains channel (so that you have both halves of the crossover for integration purposes) with a timing reference. To do this you have to have the main disconnected/off, but the timing speaker on. As an example I use surround back left so that I can turn my power amp off that powers my L and R, then measure the sub on the left channel. When sending 20Hz to the left channel my processor does its bass management and sends the 20Hz to the sub. Disconnecting the left would also work. If you use the Left as your timing reference though it can get complicated.

Bear in mind that you don't have to use the left channel for the sub, it's just easy. You can use any non-full range channel, just don't use LFE as that's not crossed over.
 

tebbo65

Active Member
There's three things here:
  • the ability to change an Umik's sensitivity, which is the thread I linked. That's still the case and isn't an issue, it just allows you to change it's profile to suit your needs and levels.
  • the incorrectness of the cal files. That's been resolved and new cal files have been published. It's completely different from the dip switches though, sorry if I confused things.
  • issues with the Umik-2, which I believe are resolved now as well. I'm still not sure that there's much need to upgrade.

Completely agree about not wanting to touch the umik. If it works, don't break it!

Yes, you should use acoustic timing references. Basically it plays a little blip (the timing reference) from the chosen speaker before taking a measurement. With that REW has a fixed reference that it can align all measured responses to so things like the speaker delays and the alignment tool work correctly. Without it REW isn't able to line up different measurements accurately. You won't always need it but it's a good habit to be in. Guaranteed the time you want it you won't have it of you're not in the habit.

The difficulty is usually around being able to measure subs on a mains channel (so that you have both halves of the crossover for integration purposes) with a timing reference. To do this you have to have the main disconnected/off, but the timing speaker on. As an example I use surround back left so that I can turn my power amp off that powers my L and R, then measure the sub on the left channel. When sending 20Hz to the left channel my processor does its bass management and sends the 20Hz to the sub. Disconnecting the left would also work. If you use the Left as your timing reference though it can get complicated.

Bear in mind that you don't have to use the left channel for the sub, it's just easy. You can use any non-full range channel, just don't use LFE as that's not crossed over.
Great, concise understandable reply, thank you so much :thumbsup: .
Umik subject undrstood.
My Emotiva PA powers L,R,C and surrounds and the Nak powers rears and overhead,s so easy to switch as you suggest if I use one of the rears as the timing reference.

Great advice, cheers.
 

MI55ION

Distinguished Member
Finally got my UMIK-1 and MiniDSP 2x4HD yesterday via NLpost & Parcel Force, phew! Result though, no import duty or VAT to pay (hope no employee of HMRC reads this). So total cost was £270, result!

@Conrad. & @MI55ION and anyone else that's interested. See the attached file for a quick comparison of the XTZ mic v UMIK-1.
Centre channel. Room correction off. As near as dammit the same mic position. Psychoacoustic smoothing applied. O degree cal file (UMIK-1), both mics pointed directly at speaker.
View attachment 1447793
Not too much difference in the results maybe the UMIK is a little more sensitive at the upper end. The big difference was with the XTZ mic the AVR's main volume setting was at -5dB and I had to bump the mic recording level setting in windows up to about -20ish dB and still only got an average of about 63dB in the REW measurement. However using the UMIK-1, the AVR's main volume is at -25dB and the mic recording level is at -9.9dB and yet the measurement level is averaging about 75dB? Maybe something to do with the XTZ external sound card?
Any how, so far I have a lot more confidence in using the UMIK-1 for REW but will keep the XTZ RA Pro ll kit as it is handy for quick measurements like testing for room modes and I do like the RTA function. It's just a pain as it's an analogue connection to the AVR and you have use Multi Ch Stereo and physically unplug the speakers you don't want to measure, whereas REW over HDMI using ASIO4ALL v2 is a breeze being able to select an individual speaker on the fly.
Going to check I've got all the ASIO/REW settings correct. Then take a ton of measurements as I've got new seating and can better position all speakers, make sure the room treatment is correct and doing it's job, then get into the setting up subs using the 2x4HD.
Good use of lock down time me thinks ;) !

Nice one. Looks to be within the marginal of error once level matched.

What's connected analogue to AVR?
 

tebbo65

Active Member
Nice one. Looks to be within the marginal of error once level matched.

What's connected analogue to AVR?
The audio out from the XTZ external sound card. Obviously only when using the XTZ software.
 

tebbo65

Active Member
Oh right, never used that software tbh.
Pain in the butt to be honest. You have to select multi stereo then unplug every speaker you don't want to measure. It is easier as I can isolate half by turning off one of the power amps but still a faff and antiquated compared to REW via HDMI.
Question, does it make a difference what sound mode I select when taking REW measurements as long as room correction is disabled?
 

Conrad.

Moderator
Probably not, unless it's affecting the levels by rebalancing. Best to make sure and just use direct.
You might want to measure with room correction on as well, just so you can do a before/after comparison.
 

tebbo65

Active Member
Probably not, unless it's affecting the levels by rebalancing. Best to make sure and just use direct.
You might want to measure with room correction on as well, just so you can do a before/after comparison.
So in direct I'll still be able to select all channels? Cool.
I do have to laugh because I must have taken hundreds of measurements today with and without correction engaged.
I'm focusing more without to get response as flat as possible pre calibration by altering speaker placement and moving room treatment about. All the base layer measures great apart from the Mains & Centre which drop off from about 10kHz. I removed all absorbers and still get the drop off. Same speakers measure flat when in the surround position. So I'm on the odd situation where I need to make the room more lively. If I use full range Audyssey correction it sorts it out perfectly. However I would like to limit correction at the rooms Schroeder frequency (238Hz). I can't remove anymore adsorption from the room, wife wouldn't appreciate me ditching the curtains, carpet or sofa 🤣.
I haven't a clue where to place diffusers and not sure they would work?
Do you think I should just let Audyssey correct the front 3 full range and forget about it?
 

Conrad.

Moderator
First, that's a good approach. Align the speakers, get them in the best positions, align the subs with phase to get the best response without EQ then let auto EQ do the least work possible.

That's interesting about the speakers, do you think it's the ribbon tweeter that's causing it (combined with the room)? Do you have dome tweeter speakers you could try in the same place?

How far off do they fall over 10kHz? If it's just 3-4dB you could just call it a Harman curve and be done with it. How does it sound with the drop off?

What about adding to the hard surfaces, like mirrors? Seems odd to be suggesting it!

Personally I don't run Audyssey as I think it sucks the life out of my speakers in my room. I might go back to it this weekend and see if I can boost my mids. Either that or switch to one of those new lovely Anthem processors!
 

Conrad.

Moderator
One more thing, if you want to measure multichannel in REW you need to set windows to 5.1/7.1 output, the channels in REW will only appear if windows presents them.
 

tebbo65

Active Member
First, that's a good approach. Align the speakers, get them in the best positions, align the subs with phase to get the best response without EQ then let auto EQ do the least work possible.

That's interesting about the speakers, do you think it's the ribbon tweeter that's causing it (combined with the room)? Do you have dome tweeter speakers you could try in the same place?

How far off do they fall over 10kHz? If it's just 3-4dB you could just call it a Harman curve and be done with it. How does it sound with the drop off?

What about adding to the hard surfaces, like mirrors? Seems odd to be suggesting it!

Personally I don't run Audyssey as I think it sucks the life out of my speakers in my room. I might go back to it this weekend and see if I can boost my mids. Either that or switch to one of those new lovely Anthem processors!
I could try a spirit from the bedroom, good call. If it proves the ribbons are the issue Beryllium upgrades might be called for 😱.
I'm losing about 6dB. I'll post graphs tomorrow.
Introducing strategically reflective surfaces might be a goer... Mirrors... Reflective 😂, nice 1.
Funny you say about not using Audyssey hence why I'm trying to get as close as dammit without. My plan was to get good raw responses. Use the miniDSP 2x4HD to eq the subs. Run Audyssey but limit or totally disregard correction via the Audyssey MultEQ editor app, dependent on speaker pair results.
Anthem upgrade = Nice! The AVM70 looks awesome. Sod it go Trinnov 😉
 
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tebbo65

Active Member
One more thing, if you want to measure multichannel in REW you need to set windows to 5.1/7.1 output, the channels in REW will only appear if windows presents them.
Yeah, sussed that... Ta.
 

tebbo65

Active Member
I could try a spirit from the bedroom, good call. If it proves the ribbons are the issue Beryllium upgrades might be called for 😱.
I'm losing about 6dB. I'll post graphs tomorrow.
Introducing strategically reflective surfaces might be a goer... Mirrors... Reflective 😂, nice 1.
Funny you say about not using Audyssey hence why I'm trying to get as close as dammit without. My plan was to get good raw responses. Use the miniDSP 2x4HD to eq the subs. Run Audyssey but limit or totally disregard correction via the Audyssey MultEQ editor app, dependent on speaker pair results.
Anthem upgrade = Nice! The AVM70 looks awesome. Sod it go Trinnov 😉
Done some measurements and it's created a dilemma so need opinions/advice.
One thing to note the dip starts at 2.5Kz not 10Kz as I previously suggested, goodness knows why I said 10Kz. Crossover point from Mid driver to tweeter 3500Hz.
Centre Blue Aud on Red Pure.png Centre. Red = Pure Mode, Blue = Audyssey Ref.
Left Main Blue Aud Ref Red Pure.pngLeft Main. Red = Pure Mode, Blue = Audyssey Ref.
Left Main Pure Blue 99.35 Red Spirit 6.pngPure Mode. Blue = Left Main, Red = Spirit 6.

As @Conrad. correctly suggested it does look like the way the XTZ36's are interacting with the room. Although the dip starts 1kHz lower than the mid driver/tweeter crossover point.

Options I'm thinking of are,
  1. Altering speaker positions & maybe introducing reflective surfaces to increase liveliness then re-introduce absorption if/as necessary.
  2. Depending on how successful opt 1 is, manipulate the dip to create a Harman curve as @Conrad. suggests.
  3. Use full Audyssey correction. Not really keen on this one as I would like to limit correction to the transition (Schroeder) point and let the speakers sing. However I do think they sound better at the moment with full correction applied due to the loss in output without.
  4. Obviously as proved with the Spirit 6 experiment new speakers may solve the issue but an over the top solution.
Fully aware I may be over sweating on this one but as the same speakers measure flat in the surround positions I would like to see if I can make the front 3 improve.

Your thoughts are highly anticipated, Tebbo.
 

pops107

Active Member
Hi just getting in to room measurement with rew what smoothing setting do you all use ?
 

Conrad.

Moderator
Use variable. That doesn't apply any smoothing to the subs and gradually increases the smoothing up the frequency range.

If it's sub only then none also works.
 

pops107

Active Member
Great thanks for that

Still learning the software

Have done a bit of tweaking and running a anti-Mode only measuring sub at the moment going to move on to speakers
 

pops107

Active Member
This is where I am now

Red anti-mode on bypass
Green flat eq
Blue 25hz lift

Any advise or does it look good or not good ??
 

Attachments

  • IMG-20210126-WA0006.jpg
    IMG-20210126-WA0006.jpg
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Conrad.

Moderator
A few things:

  • there's a camera icon on the top right, use that for taking screenshots rather than photos, it gives a clearer picture.
  • Change the scale to logarithmic (hit the Freq Axis button at the top right)

Edited to say that I didn't read your post, sorry.

Blue would be my preferred option, it would be interesting to see whether those lifts cause you any headroom issues. The way to check for that is compression sweeps where you measure, then increase the volume by 3dB and measure again. If the measurement doesn't rise by 3dB across the frequency range then you've reached the limits of the sub.

That may or may not be a problem depending on where that limit is and whether that limit is loud enough for you. It's also worth looking at the distortion tab and seeing if the distortion is rising to unacceptable levels.
 
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pops107

Active Member
Thanks for the quick reply and great advice will have another measure and will try the 3db increase see what I get

I should of mentioned the sub is a bk xxls400

To my ear's blue sounds the best
 

Conrad.

Moderator
Both blue and green should sound much better than orange. The antimode has tamed that large peak at 50Hz which will have been dominating the response and clouding everything else.
 

pops107

Active Member
My system sounded so much smoother and the front 3 and my sub sound way more integrated
 

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