60 Degree DIY Mid Hi - AKA PM60

[Raimonds Skuruls]

Re: 60 Degree DIY Mid Hi

Hi Raimonds,
I've read your article and Dr. Toole's and am trying to take it all in. I'm primarily doing live SR so I'm trying to make that application.

I downloaded the trail version of your TDA software to give it a try and see how it would help a DIYer like me on a project like this. I ran a test on one of the DIYs with a 60 deg horn in it. Not exactly sure what I'm looking at though. Here are some screen captures of the TDA, AFR and DFR plus the Smart trace from the same session. There are no subs used during this test.

Hi Don,

Nice job! Nice results!
Let’s go forward with accuracy!
Peter has already pointed to resonances. I would like to do that in more details.
Please take a look on your images attached.
You can see resonances in both diagrams: as smearings on TDA image and bumps on AFR image as well.
The AFR curve of TDA is not „showing” resonances in all details because the TDA process is for timing analysis – the resolution of AFR is sacrificed for high timing resolution.
Another story is with TDA EQ. It is capable to hook out AFR information to be used for EQ.
Let’s try how it works for your speaker. Please download the testsignal of TDA EQ
http://aplaudio.com/downloads/TS_48_96k_25p.rar
Play it and record by use of measurement mic. Send recorded file to me.
It contains 25 sweeps. You should move the measurement mic all the recording time to cover some square (25 x 25 points) in front of your speaker to cover some + - 5...10 degr. around the axes.

Good luck,

Raimonds

 

[Don J Davis]

Re: 60 Degree DIY Mid Hi

Hi Don,

Nice job! Nice results!
Let’s go forward with accuracy!
Peter has already pointed to resonances. I would like to do that in more details.
Please take a look on your images attached.
You can see resonances in both diagrams: as smearings on TDA image and bumps on AFR image as well.
The AFR curve of TDA is not „showing” resonances in all details because the TDA process is for timing analysis – the resolution of AFR is sacrificed for high timing resolution.
Another story is with TDA EQ. It is capable to hook out AFR information to be used for EQ.
Let’s try how it works for your speaker. Please download the testsignal of TDA EQ
http://aplaudio.com/downloads/TS_48_96k_25p.rar
Play it and record by use of measurement mic. Send recorded file to me.
It contains 25 sweeps. You should move the measurement mic all the recording time to cover some square (25 x 25 points) in front of your speaker to cover some + - 5...10 degr. around the axes.

Good luck,

Raimonds

Thanks Raimonds & Peter for the feedback!
Raimonds, I'll try and find some time soon to perform the measurements your suggesting.

Don

 

[Mark Wilkinson]

Re: 60 Degree DIY Mid Hi

I finally had a chance to use the 2 per side set up at an outdoor event yesterday. It was a inner city Thanksgiving dinner provided by some local churches.
The coverage was a bit of a stretch with a venue this wide but it was pretty acceptable considering.
The tops were powered by itech 4000's and there were 8 SRX718 subs across the front powered one sub per channel of itech 4000s. The tops easily out ran the subs.
IMO it sounded amazing. There were both live acts and a DJ. It is a very responsive system to mix on.
All in all I couldn't be more pleased with Peter's design!
I wasn't sure how to post a video on the forum so here its a Facebook link. Hope it works.
https://www.facebook.com/don.davis.522/videos/1060677433976416/
Also a screen shot of the set up.

Nice rig Don !
Glad all worked well for you. So I guess you used 6 itechs for the 4 diys? What splay angle did you use?
How many 718's do you think would have been a fair match? I'm finding 1 diy is having no problem with 2 jtr orbit shifters (outside)

 

[Don J Davis]

Re: 60 Degree DIY Mid Hi

Nice rig Don !
Glad all worked well for you. So I guess you used 6 itechs for the 4 diys? What splay angle did you use?
How many 718's do you think would have been a fair match? I'm finding 1 diy is having no problem with 2 jtr orbit shifters (outside)

Hi Mark,
Thanks, we used 4 iTechs for the tops and 4 for the subs. There are 6 XTIs in the set up for biamped wedges.
Hard to say but guessing at how hard the amps for the tops looked to be working vs the subs I'd say that 2x subs would have been a closer match.
The splay angle we used was really wide due to how wide an area we were trying to cover. I've been using the 2 a side set up in a 600 cap chapel and about 35deg is pretty good.
In that chapel we only use 4 subs. I have had to change my gain structure since using the DIYs vs the SRX712s for tops, the DIYs are way more sensitive. The DIYs are definitely just loafing along.

 

[Raimonds Skuruls]

Re: 60 Degree DIY Mid Hi

Hello Colleagues,

The discussion with Dr. Floyd Toole about his paper
“The Measurement and Calibration of Sound Reproducing Systems”
should be interesting to you.
The paper and start of discussion is available at AES forum:
https://secure.aes.org/forum/pubs/journal/?ID=524
Than the administrator of AES forum William McQuaide have decided:
“So we do not think that our readers will benefit from further postings”
and denied next post.
All discussion is available here: http://aplaudio.com/downloads/Reading_Dr_Toole.pdf

 

[Peter Morris]

Re: 60 Degree DIY Mid Hi

FWIW here are a few DIY gig photo's - The 90 degree version is proving to be the most useful.

 

[Mark DeArman]

Re: 60 Degree DIY Mid Hi

Than the administrator of AES forum William McQuaide have decided:
“So we do not think that our readers will benefit from further postings”
and denied next post.

This is why AES can not get the active participation in the Journal forum. I am assuming that you are not a native English speaker, but I didn't find the tone of what you wrote to be non-beneficial to discussion on the topic.

 

[Don J Davis]

Re: 60 Degree DIY Mid Hi

FWIW here are a few DIY gig photo's - The 90 degree version is proving to be the most useful.

Excellent! The 90s are most handy.

Did you use the 90s or the 60s on the outdoor gig on the track? What does the 137m measurement signify?

The dLive looks fantastic, on my "If I hit the lottery" wish list.

 

[Peter Morris]

Re: 60 Degree DIY Mid Hi

Excellent! The 90s are most handy.

Did you use the 90s or the 60s on the outdoor gig on the track? What does the 137m measurement signify?

The dLive looks fantastic, on my "If I hit the lottery" wish list.

I used 2 x 60 degrees on the oval. The 137m or 450 ft was just to add some scale - the picture was taken at about 150ft. It was loud an clear at that point.

The dLive is absolutely fantastic - the best UI out there ... next week its doing monitors for a large Xmas show, I think we will be using 64 in and 35 outs! ... lots of stereo IEM sends.

 

[Don J Davis]

Re: 60 Degree DIY Mid Hi

Hi Don,

The AFR curve of TDA is not „showing” resonances in all details because the TDA process is for timing analysis – the resolution of AFR is sacrificed for high timing resolution.
Another story is with TDA EQ. It is capable to hook out AFR information to be used for EQ.
Let’s try how it works for your speaker. Please download the testsignal of TDA EQ
http://aplaudio.com/downloads/TS_48_96k_25p.rar
Play it and record by use of measurement mic. Send recorded file to me.
It contains 25 sweeps. You should move the measurement mic all the recording time to cover some square (25 x 25 points) in front of your speaker to cover some + - 5...10 degr. around the axes.

Good luck,

Raimonds

Hi Raimonds,
I had a chance to run the test sweeps. I sent you a message.
Here are the plots from that session.
There is still something going on around 300hz but the rest looked pretty good.
I used the system again this past weekend and had people commenting on the sound and how they could hear every instrument.

 

[Peter Morris]

Re: 60 Degree DIY Mid Hi

Hi Raimonds,
I had a chance to run the test sweeps. I sent you a message.
Here are the plots from that session.
There is still something going on around 300hz but the rest looked pretty good.
I used the system again this past weekend and had people commenting on the sound and how they could hear every instrument.

Hi Don,

That's looking great ... still a few tweaks but when you get to that level it will sound so good, probably better than any other PA speaker you have heard

Peter

 

[Darren Scaresbrook]

Re: 60 Degree DIY Mid Hi

Who's that good looking guy in the picture lifting the DIY onto the pole? ~;-)~:wink:

 

[Mark Wilkinson]

Re: 60 Degree DIY Mid Hi

Hey guys, beginning to get the feel for Smaart.... I think....
Currently playing with just aligning/smoothing the 4594 indoors at about 2 ft. (with IIR)
No MID involved. I'm thinking room reflections shouldn't be a problem here?

Does the HF section of the coax necessarily need to be low passed? Looks like it rolls off real fast on its own a little above 6k....

 

[Peter Morris]

Re: 60 Degree DIY Mid Hi

Hey guys, beginning to get the feel for Smaart.... I think....
Currently playing with just aligning/smoothing the 4594 indoors at about 2 ft. (with IIR)
No MID involved. I'm thinking room reflections shouldn't be a problem here?

Does the HF section of the coax necessarily need to be low passed? Looks like it rolls off real fast on its own a little above 6k....

Yes the VHF section MUST be high passed and the HF section low passed.

In the case of the VHF section to protect it from thermal and Xmax issues. The HF section even though it rolls of there is still output there. The VHF will not sound as nice if the output of the HF driver is sitting under the VHF drivers output.

 

[Mark Wilkinson]

Re: 60 Degree DIY Mid Hi

Yes the VHF section MUST be high passed and the HF section low passed.

In the case of the VHF section to protect it from thermal and Xmax issues. The HF section even though it rolls of there is still output there. The VHF will not sound as nice if the output of the HF driver is sitting under the VHF drivers output.

Thx Peter, totally understood the MUST need to high pass VHF for reasons stated.
Thought I found a real nice combo, phase and transfer, using no low pass on HF and 24db bessel high pass on VHF at 6k4, 0.26 ms delay on HF. Polarity (-) VHF
Oh well

 

[Peter Morris]

Re: 60 Degree DIY Mid Hi

Thx Peter, totally understood the MUST need to high pass VHF for reasons stated.
Thought I found a real nice combo, phase and transfer, using no low pass on HF and 24db bessel high pass on VHF at 6k4, 0.26 ms delay on HF. Polarity (-) VHF
Oh well

The HF section drops off nicely from about 6kHz to about 10 - 12kHz and then (AFAIK) it peak again around 16kHz . Its this peak where there will be a problem. If you can reduce that a little with a LP filter at around 12kHz (just a guess) what you are trying to do may just work. Bottom line - what ever sound the best in this case. ~~:smile:

 

[Raimonds Skuruls]

Re: 60 Degree DIY Mid Hi

Thanks Raimonds & Peter for the feedback!
Raimonds, I'll try and find some time soon to perform the measurements your suggesting.

Don

Hi Don,

Thanks for files!
Here you are, your results: the FIR EQ offered by TDA EQ,


the TDA images before


and after EQ


and AFR of the result.

 

[Don J Davis]

Re: 60 Degree DIY Mid Hi

Hi Don,

Thanks for files!
Here you are, your results: the FIR EQ offered by TDA EQ,

Raimonds,
Thank you very much! I was able to try adding the EQ suggested by your program prior to my event last night. I was originally skeptical about the amount of cut in the 125 - 450hz range but once I added it, the system really opened up.
Last night was the best sound I've had so far from DIYs. Extremely clear and detailed.

The TF in Smaart was anything but flat but the system sounded fantastic. How does TDA differ from FFT?

I didn't have a great deal of time to refine things but am really looking forward to working on some final settings using your program.

 

[Peter Morris]

Re: 60 Degree DIY Mid Hi

Raimonds,
Thank you very much! I was able to try adding the EQ suggested by your program prior to my event last night. I was originally skeptical about the amount of cut in the 125 - 450hz range but once I added it, the system really opened up.
Last night was the best sound I've had so far from DIYs. Extremely clear and detailed.

The TF in Smaart was anything but flat but the system sounded fantastic. How does TDA differ from FFT?

I didn't have a great deal of time to refine things but am really looking forward to working on some final settings using your program.


~~:smile:… Raimond’s software gives great results. I suspect you are now getting the sound quality I have been talking about. It’s quite special, and if I do say so myself, I have not heard better.
It’s nice to know other people are getting the box to that point. Thanks for your input into this project Raimonds.

 

[Raimonds Skuruls]

Re: 60 Degree DIY Mid Hi

Thanks Peter, Don,

“How does TDA differ from FFT?”

FFT is working in frequency domain and its time resolution depends on data block size of analysis.
TDA is not leaving time domain. It is like two dimensional (time, amplitude) Impulse Response but with one more dimension – frequency – added. We have 3D timing image of our system as result.


“ … looking forward to working on some final settings …”

Next logical step, in using high accuracy offered by TDA, is to use FIR filter to implement corrections. The VST plagin is good for initial evaluation how it works.