New system measuring tool

[JonFo]

We frequently talk about how one can accurately measure the system response (in-room) to help provide placement and system tuning feedback.

There is a new affordable ($300) kit coming out that looks pretty nice. The folks involved definitely have the right pedigrees.


Dayton OmniMic Precision Measurement System

As I always say, an audiophile without a measurement system is like a carpenter without a tape measure.

 

[RUR]

Been waiting for Kal's review and/or first user comments before I pull the trigger. Appears that initial deliveries began yesterday, so we should have some of that commentary soon.

 

[tsv_1]

This looks great, especially at that price point. Thank for pointing it out.

 

[sleepysurf]

Interesting! Looks like it could give the XTZ Room Analyzer some stiff competition at that price point! Hopefully we'll start seeing some reviews shortly.

 

[MPS]

Hmm... there is freeware software available and reasonable soundcard & measurement mic can be easily had for ~200 but I like the idea of complete package.

 

[Peter_Klim]

This looks great, especially at that price point. Thank for pointing it out.

I agree, that does look like a good price. I would love to get the more expensive ones I've seen before, but they are pricey. I just thought of something - maybe they can be rented. Then I would just rent it each time something was changed in my system.

 

[Peter_Klim]

I found a video for it, or rather a similiar one (differetn part #) on YouTube:

YouTube video

 

[User211]

OK let's call the bluff on this one.

Somebody buy one, post your in-room response curves, then try and show us all how you improved the response by purchasing room treatments.

I'm not scared - I've posted my in-room response already. Only I don't think I am mad enough to believe I can improve it by any worthwhile manner by spending gob-loads on room treatments.

I know full well from the measurements I've taken I can tune it by changing amps, changing output tubes, using tone controls etc...

There is a remarkable lack of proof of concept on this forum with regards to this. But much verbosity advocating there use. It'd be nice to see someone actually proving that they have made room treatments work well - at least in the field of straight forward frequency response.

Most UK audiophiles seem to buy room treatments, use them for a while, then get rid of the things...

EDIT: OK this is a mild wind up to elicit a response. I do know treatments will make a difference, but targeting specific problem areas accurately and by the right amount of DBs? Hm...

 

[tsv_1]

EDIT: OK this is a mild wind up to elicit a response. I do know treatments will make a difference, but targeting specific problem areas accurately and by the right amount of DBs? Hm...

For me it's not so much getting a ruler-flat response (monarchical or otherwise), but more investigating where the real anomalies are in my room(s) across the frequency range. If it's something I can compensate for with speaker movement, listening position change, or some minor treatment... the tool will help me during the evaluation. I've no desire to go hog-wild on treatments - my room is nearly treatment free as it is. But for 300 smackers, this seems like an interesting tool IMO.

Response elicited

 

[User211]

Good attitude, Todd. Seriously.

I got a bit of a shock a few days ago using my iPhone and AudioTools - did yet another in-room FR FFT plot and got a real shock - what has happened to the HF response? It had taken a profound dip for the worse. Decidedly rolled off treble.

Nothing had changed. Or had it, I pondered?

iPhone app updates occur with alarming rapidity - could it be that was the reason? If I leave the phone for a few days I usually end up having to do about 20 odd updates for bug fixes. Low and behold this morning another Audiotools update comes through with a list of bug fixes - including a fix that corrected the previous release's (only seemingly a few days before) bad mic compensation tables. These are apparently now better than ever - so I will retry.

When taking FR plots with the Apogee restorer whlst trying to cure a sibilance/perceived brightness problem after a ribbon/x-over upgrade he made a pretty cool statement - the test kit should only be regarded as a tool and not an absolute. Just use it as a guide.

Perceived problems can best be resolved by other means - in this case swapping inductors - where little can be positvely measured to prove there was a real problem/issue in the first place. Sure it makes you question your sanity and hearing ability - but that is all part of the fun I suppose

 

[Hocky]

Do you really think that the iphone mic is accurate and/or precise enough to give you any kind of meaningful information? I've played with it a bit and found it to be mediocre at best. :-\

If the reviews are good, I think I will probably pick one of these systems up. Not for room treatments, but because my speakers/sub have 25/50hz knobs and for sub eq work.

 

[User211]

Do you really think that the iphone mic is accurate and/or precise enough to give you any kind of meaningful information? I've played with it a bit and found it to be mediocre at best. :-\

If the reviews are good, I think I will probably pick one of these systems up. Not for room treatments, but because my speakers/sub have 25/50hz knobs and for sub eq work.

How did you decide it was mediocre?

I've recorded with it and it is pretty good. Not as good as a Rowland Eidrol HR by any means, but acoustic guitar played back well. I've measured with it and it has returned consistent results until the compensation table mess up. It is good enough for basic in-room FR plots.

The $300 you pay for that is a lot more than the $40 odd you'll pay for Audiotools (depending on options) IF you have an iPhone.

It's good enough to align a Descent with - agreeing almost 100% with where I thought the Descent settings should be by ear.

If you can't accept it then buy an iRig and use an external mic. The software is very easy to use and that's one of the reasons I like it.

I understand doubters here. Believe me

http://www.audiotool.com/

 

[RUR]

...There is a remarkable lack of proof of concept on this forum with regards to this. But much verbosity advocating there use. It'd be nice to see someone actually proving that they have made room treatments work well - at least in the field of straight forward frequency response....

Presumably you've read Jonfo's excellent thread here? http://67.19.167.226/~tdacquis/forum/showthread.php?t=5435

FR tweaking isn't the most important reason for room treatments, BTW.

 

[Hocky]

How did you decide it was mediocre?

I've recorded with it and it is pretty good. Not as good as a Rowland Eidrol HR by any means, but acoustic guitar played back well. I've measured with it and it has returned consistent results until the compensation table mess up. It is good enough for basic in-room FR plots.

The $300 you pay for that is a lot more than the $40 odd you'll pay for Audiotools (depending on options) IF you have an iPhone.

It's good enough to align a Descent with - agreeing almost 100% with where I thought the Descent settings should be by ear.

If you can't accept it then buy an iRig and use an external mic. The software is very easy to use and that's one of the reasons I like it.

I understand doubters here. Believe me

http://www.audiotool.com/

I just say that it is mediocre because on my phone, I could not yield consistent results and I question the accuracy of what I did get as an overall average. I would guess that the overall quality of the phones are just too far ranging for it to be a good tool - mine wasn't worth while.

 

[User211]

Presumably you've read Jonfo's excellent thread here? http://67.19.167.226/~tdacquis/forum/showthread.php?t=5435

FR tweaking isn't the most important reason for room treatments, BTW.

No actually, but I will do, and yes, I know - we all remember Ethan's contributions here I'd hope.

 

[User211]

I just say that it is mediocre because on my phone, I could not yield consistent results and I question the accuracy of what I did get as an overall average. I would guess that the overall quality of the phones are just too far ranging for it to be a good tool - mine wasn't worth while.

Was it an iPhone 4 with Audiotools?

Measuring frequency response is a bit surreal and you may see huge changes with small movements in the phone's position - especially with ML's due to the narrow sweet spot and the need for super precise alignment via flashlight. I never tried it with MLs.

Just moving the mic's orientation with respect to the speaker will make big changes.

Go buy the $300 solution... it should be better. But you can't stick it in your pocket. You can't walk into a hi-fi show and ask them to play a pink noise disk for 20 seconds to get an idea. You can't (as) easily take it round to enthusiast hi-fi events. Personally I'd just get an external mic for the iPhone if you have one.

I like it. I expect to get questioned on it. I know it has limitations but after playing with a Behringer measurement mic and a laptop I am NOT convinced that was actually much better.

Jon is in the business of developing iPhone s/w. Be interesting to see if he has had a play and what he thinks.

 

[JonFo]

OK let's call the bluff on this one.

Somebody buy one, post your in-room response curves, then try and show us all how you improved the response by purchasing room treatments...

Oh, good god, please. Use the search tool and then spend the rest of the day reading my posts on the topic, plenty, and I mean plenty of measurements to prove the value of treatments.

Start here: http://67.19.167.226/~tdacquis/forum/showthread.php?t=5435

In any case, the tool is not about whether treatments work or not, its about being objectively informed about the impact of any change one makes to setup.

 

[JonFo]

Do you really think that the iphone mic is accurate and/or precise enough to give you any kind of meaningful information? I've played with it a bit and found it to be mediocre at best. :-\

If the reviews are good, I think I will probably pick one of these systems up. Not for room treatments, but because my speakers/sub have 25/50hz knobs and for sub eq work.

The iPhone setup is no where near as accurate as a setup like the one being discussed, but for the money, it's an amazing value. Better than nothing, that's for sure.

I use the iPhone 4 and AudioTools to perform basic system assessment or tuning at friends homes. When I first walk in, the sub is usually turned up waaay to high, and the mains will have some nasty suck-out due to positioning. Showing the friend the problems, then the 'after' measurements makes them believers.

 

[User211]

Oh, good god, please. Use the search tool and then spend the rest of the day reading my posts on the topic, plenty, and I mean plenty of measurements to prove the value of treatments.

Start here: http://67.19.167.226/~tdacquis/forum/showthread.php?t=5435

In any case, the tool is not about whether treatments work or not, its about being objectively informed about the impact of any change on makes to setup.

I must have been dead for a while...:ROFL:

Missed it completely and not a single post on the thread so my memory doesn't fail me.

 

[User211]

The iPhone setup is no where near as accurate as a setup like the one being discussed, but for the money, it's an amazing value. Better than nothing, that's for sure.

That's the point I'm trying to make.

But assuming the headphone A/D input is linear, a decent mic will make it extremely good.