REW and Focusrite Liquid Saffire 56 - 5.1 System

[Dave1952]

Good evening Matthew, Wow, you have given me lots to read and absorb for sure.... Just in the graphs it's going to take some time to figure out all that is being displayed!

Being new to REW i need to find the best set up for me to send you a file or files on the set up I have now.. I"m not sure that I have the correct set up with the interface and something is creating some weird graphs...

I am getting ready for a 2 day session on Thursday and Friday and then leaving on Saturday for a trip to Northern California, we will be back on the 27th and have some time to look in to all this.

Not to worry, I'm not looking for a $200 pair of speakers and, $2500 to $5000 is not out of line so finding the right balance is what I am trying to get to... I've not looked for "Used" monitors in the past it is just too big of a gamble with out the right testing procedures.


Dave

 

[Dave1952]

By the way Matthew, Were are you located?

 

[Matthew J Poes]

By the way Matthew, Were are you located?

Chicago Burbs

 

[Matthew J Poes]

Good evening Matthew, Wow, you have given me lots to read and absorb for sure.... Just in the graphs it's going to take some time to figure out all that is being displayed!

Being new to REW i need to find the best set up for me to send you a file or files on the set up I have now.. I"m not sure that I have the correct set up with the interface and something is creating some weird graphs...

I am getting ready for a 2 day session on Thursday and Friday and then leaving on Saturday for a trip to Northern California, we will be back on the 27th and have some time to look in to all this.

Not to worry, I'm not looking for a $200 pair of speakers and, $2500 to $5000 is not out of line so finding the right balance is what I am trying to get to... I've not looked for "Used" monitors in the past it is just too big of a gamble with out the right testing procedures.


Dave

Sounds good Dave. I hope your trip goes well. I hear you on used monitors.

The graphs are frequency by amplitude by angle. What they show is how the frequency response (also sometimes called the loudness response) varies with angle. The behavior you see on the first graph is near ideal behavior. A perfect speaker would have perfectly smooth lines and every line would follow the trajectory of the line above it but at a different level. What that means in practice is that a perfect monitors response would always sound the same at every angle but the volume level would be lower as you move to the side of the speaker. That makes it so a speaker has built in first-reflection treatment. It also stabilized the center image so that no matter where you move the center image always stays put.

Most modern Genelec speakers behave in a near ideal fashion. The Dutch & Dutch 8C does so to a lower frequency. So does the Kii Audio. Neumann monitors are also good and show similar behavior.

Dynaudio and Focal are examples of two brands which do not behave in this way. They have a wider response initially but becoming more corrupted as you move off-axis.

Having said all of this, while I am a believer in the superiority of constant directivity speakers, I have heard plenty of speakers that don’t meet this criteria that i thought sounded good. Our ears may be immune to some of this distortion of the polar response and it is possible that even speakers with poor polar response can sound fine. It may be, at least a little bit, an academic exercise to create this ideal speaker. Still, if it is ideal and it’s possible, why not do it.

 

[Dave1952]

Evening Matthew,
Our sessions got reschedule to the first of next year (which for me is fine)... I have not found the magic hookup on our system with the REW and I"m not exactly sure why... but I have run out of time at this point until after the first of the year..

In the mean time, I had run my RTA with my Berhinger and mic, on 90 degree pointed at the speakers. I pointed them from my listening position and were proably 5' away. In the Photos because I can't freeze them I just take a couple of shots of each speaker and the increments on the RTA are set at 1db per... I am going to do it again at .05db when I get back... here is a few shots of the response... These were in April of this year.

I'd really like to see what I can get with REW...and at this point I might just order the USB mic and skip the interface hassle.... I see others having issues on dealing with multiple input Interfaces.... to make it easier I think the USB mic might be quicker :-)

 

[Matthew J Poes]

Evening Matthew,
Our sessions got reschedule to the first of next year (which for me is fine)... I have not found the magic hookup on our system with the REW and I"m not exactly sure why... but I have run out of time at this point until after the first of the year..

In the mean time, I had run my RTA with my Berhinger and mic, on 90 degree pointed at the speakers. I pointed them from my listening position and were proably 5' away. In the Photos because I can't freeze them I just take a couple of shots of each speaker and the increments on the RTA are set at 1db per... I am going to do it again at .05db when I get back... here is a few shots of the response... These were in April of this year.

I'd really like to see what I can get with REW...and at this point I might just order the USB mic and skip the interface hassle.... I see others having issues on dealing with multiple input Interfaces.... to make it easier I think the USB mic might be quicker :-)

Sure get the USB mic and see if that helps. I’m using a MOTU 828x and it took a bit for me to get it all working. I actually plan to do a more detailed video on how to use REW that I hope will help.

 

[Dave1952]

Morning Matthew, In my set up I choose AIS0, 44.1k, Output device is Safire Audio I've attached or uploaded a file from this morning showing you my screen shots of the preferences pages. I"ve also run some RTA Left and Right with the set up and I"ve attached the files as well as my .mdat file I don't know if I am headed in the right direction or not :-) but see what you think if I am on the right path or not.
Dave

 

[John Mulcahy]

Have you been able to confirm that the mic signal isn't getting back to the Mon1 output? Mustn't hear anything from the output if you tap the mic.

 

[Matthew J Poes]

Hi Dave,

Something doesn't seem right about this measurement. Your pictures are using a very wide dynamic scale. By constricting the scale to a more reasonable range, I see a response that is VERY tilted toward the high frequencies. In looking at your mic calibration file, it doesn't look like a good calibration file. It looks like the kinds that come with Dayton mics, too many ups and downs and no correction for the response problems.

First, I would try taking sweep measurements so I can get a better sense of the room noise, acoustics, and response. I'm not sure what is going on. All of these issues actually don't explain what is going on with your measurement. Your HF's are actually 30dB's off from the low frequencies. That implies something is wrong. Let's go ahead and do the sweeps and see what we see. That will help narrow down the possible problems.

Also, I would place the mic at your listening position and point it at the speaker for each sweep. The reason is I am not sure of the correction you are using and I worry you are seeing effects from the mics response. These mic's don't have a flat response, the HF's are quite elevated and require some general correction.

 

[Matthew J Poes]

Have you been able to confirm that the mic signal isn't getting back to the Mon1 output? Mustn't hear anything from the output if you tap the mic.

Does that feedback explain the weird tilt to the response? I have never seen anything like that. You wave way more experience than I do in the number of different things that can go wrong.

 

[Dave1952]

Well John, and Matthew thanks for the response and your right, it just seems way off... (and did when I was trying to take the measurements. Yes it is the Dayton Mic I just received and it is the Cal file I downloaded from the Dayton Website. At this point, I'm going to deal with this when I get back from our trip... it just seems like either I am doing something really wrong or my inputs and outputs are not right (but you can see my set up in preferences. Anyway, thanks for all your input, sorry I"m not getting something... I need to just get away from it for a few days and think it out better.... Perhaps a phone call could help clear this up and I can explain better rather than all these posts of the incorrect information. I'd be glad to talk with either one of you if at some point you might have the time...
Dave

 

[Dave1952]

Well, Matthew and John, after all this work, double checking inputs outputs, cables and about everything else I thought to myself... Could it be something with the Mic... So I brought out my old trusty Berhinger 8000 and just a quick look... My bet 99.9% the Dayton Audio Mic has an issue, I"ve contacted them to get a credit and when I return from our trip I"ll put another mic on order.. this time I think I"ll just buy a USB mic, the one John mentioned.. that way I can use it here in the studio with my laptop and desktop I guess.... anyway, Go figure....

So hope you guys and your families have a great Holiday and I'll be back as soon as I get the replacement mic (in the mean time I"ll be playing around with the Berhinger which I do not have a cal file for but it will give me some time to check out the software...

Thanks for your help and sorry for the issues Ive been dealing with.. just glad I decided to bring up the Berhinger after your guys comments.

Dave