60 Degree DIY Mid Hi - AKA PM60

Re: 60 Degree DIY Mid Hi

Jim dee said:
... when they actually can do the 8 way processing I want/need(I think). ....
Click to expand...


Hello

I doubt you are planning on stereo 8-way sound system ( 8L + 8R = 16total amp channels ) - two DCX2496 can be connected together to act as stereo system - so stereo 4-way is easily obtainable. On each unit 1-in 4-out leaves you two inputs and two outputs on each unit to use at something else. Plus if you wish, you can have two mono-racks - one on each side of stage - short speaker-cables.
 
Re: 60 Degree DIY Mid Hi

Hi everybody,

Peter, glad to hear your arrayed 60 deg results...thx for ongoing settings etc.

I put building another pair of 60 deg to the side for the time being, after i realized that my shredded cones had to be due to failure to high-pass, and not the tighter than plan clearances I used....

Been trying to learn smaart, and finding a testing setup that's consistent and easy.


I did get the chance to take the DIY 60 (and a JTR 3TX) into the local sound reinforcement store, and have a brief A/B to the JBL 835p. Special thanks to the kind folks at Stagesound.....

Single boxes were set up sitting on a stacked pair of JBL 828p subs. All boxes crossed at 100hz. Not optimal for individual box optimization for sure, but like said...just a quick comparison.
The room was a good room for demoing IMO....

Anyway, I really wasn't prepared for how different the 835p and the DIY sounded....
The DIY sounded so much more forward, like there was a HF lift. But as i listened to to lower mids, I realized the same forward bias was there too. The DIY simply sounded much cleaner to me...alive....but the difference in tonality was great enough, that in comparison it almost seemed like the DIY was too hyped.

Time for a little disclosure....I'm still struggling with settings for the 60 degree. Peter, I tried the ones you gave, but either I'm doing something wrong or the settings aren't compatible with the hardware i'm using for processing (QSC PLD4.5 amp.) I find I have to back off the gain 3-4db to the HF and VHF drivers with your settings and also with any settings I independently attempt.
Interestingly, none of this is the case with the 90 degree version. The settings you gave work great, without needing to back down HF/VHF gain. I kinda wished I took the 90 deg in for comparison, and waited till I completely sort out the 60....

Anyway again......., as we played with bringing the 2 boxes in line tonally, is was like trying to rein in the DIY while putting the spurs to the 835. Both sounded pretty good meeting in the middle. But even then, the DIY still sounded cleaner. And it certainly sounded like it had a lot more room to breathe....
I've become addicted to the DIY's clarity, and don't care how long it takes to sort it out the tonal finesse...I can't live in the middle anymore lol
A think there was a consensus that the DIY sounds like an incredibly powerful studio monitor..

The 3TX fared very well too. Tonally, it set in between the DIY 60 and the JBL. Very similar to the middle ground found above, and this was with zero eq on it. (FWIW, the DIY 90 sits between the 3TX and DIY 60, and closer to the 60 deg...IMO)
Again, a clearly cleaner sound to my ears than the 835. And my gut says at least as loud if pushed....something we didn't really try...

I think having the compression driver handle as low a freq range as the do is the key to the clarity in both the DIY and the 3TX.
Basically what Peter has been saying from the gitgo ! :lol:
 
Re: 60 Degree DIY Mid Hi

Hey Mark,
When I get a chance I'll print out my Driverack settings and email them to you for comparison. The key to tuning these is to get them up in the air outdoors as Peter suggests. Try and find an empty field so you're not dealing with reflections.

I used the 90 deg's this past Saturday in a 500 cap chapel with excellent results. I did have to tweak the gain settings for the VHF for this room. It seemed to require much more gain than when using the 60 deg horns. I also find myself changing all my old channel presets. I'm still getting used to mixing with much lower distortion and a relatively flat system.

Cool comparison BTW!
 
Re: 60 Degree DIY Mid Hi

Mark Wilkinson said:
Hi everybody,

Peter, glad to hear your arrayed 60 deg results...thx for ongoing settings etc.

I put building another pair of 60 deg to the side for the time being, after i realized that my shredded cones had to be due to failure to high-pass, and not the tighter than plan clearances I used....

Been trying to learn smaart, and finding a testing setup that's consistent and easy.


I did get the chance to take the DIY 60 (and a JTR 3TX) into the local sound reinforcement store, and have a brief A/B to the JBL 835p. Special thanks to the kind folks at Stagesound.....

Single boxes were set up sitting on a stacked pair of JBL 828p subs. All boxes crossed at 100hz. Not optimal for individual box optimization for sure, but like said...just a quick comparison.
The room was a good room for demoing IMO....

Anyway, I really wasn't prepared for how different the 835p and the DIY sounded....
The DIY sounded so much more forward, like there was a HF lift. But as i listened to to lower mids, I realized the same forward bias was there too. The DIY simply sounded much cleaner to me...alive....but the difference in tonality was great enough, that in comparison it almost seemed like the DIY was too hyped.

Time for a little disclosure....I'm still struggling with settings for the 60 degree. Peter, I tried the ones you gave, but either I'm doing something wrong or the settings aren't compatible with the hardware i'm using for processing (QSC PLD4.5 amp.) I find I have to back off the gain 3-4db to the HF and VHF drivers with your settings and also with any settings I independently attempt.
Interestingly, none of this is the case with the 90 degree version. The settings you gave work great, without needing to back down HF/VHF gain. I kinda wished I took the 90 deg in for comparison, and waited till I completely sort out the 60....

Anyway again......., as we played with bringing the 2 boxes in line tonally, is was like trying to rein in the DIY while putting the spurs to the 835. Both sounded pretty good meeting in the middle. But even then, the DIY still sounded cleaner. And it certainly sounded like it had a lot more room to breathe....
I've become addicted to the DIY's clarity, and don't care how long it takes to sort it out the tonal finesse...I can't live in the middle anymore lol
A think there was a consensus that the DIY sounds like an incredibly powerful studio monitor..

The 3TX fared very well too. Tonally, it set in between the DIY 60 and the JBL. Very similar to the middle ground found above, and this was with zero eq on it. (FWIW, the DIY 90 sits between the 3TX and DIY 60, and closer to the 60 deg...IMO)
Again, a clearly cleaner sound to my ears than the 835. And my gut says at least as loud if pushed....something we didn't really try...

I think having the compression driver handle as low a freq range as the do is the key to the clarity in both the DIY and the 3TX.
Basically what Peter has been saying from the gitgo ! :lol:
Click to expand...

Hi Mark,

FWIW my 90 degree boxes and 60 degree boxes sound almost identical - the 60 degree version I think is slightly better.

The latest results using FIR filters are absolutely stunning, everyone with out exception is amazed, and if I do say so myself .... I have not heard anything that sounds better :roll:

A couple of questions - are you using 8 or 16 ohm 4594s ? and I assume you are using 8 ohm RCF 12's ?.

With 16 ohm 4594 and 2 x 8 ohm 12" RCF's (in parallel) the mids should be running about 3 to 4 dB less than the HF, for an 8 ohm 4594 6 to 7 dB less ...BUT it depends on the individual processor. The way the PEQs are determined is often different between manufactures .....a problem for any DIY project.

The other issue is my 90 degree boxes are using RCFs and my 60 degree version B&Cs ... so there is variation in the mid processing between the two boxes.

Can you send me what you used and I will check it out. Also check out what Don is using. We all may need to come up with a few different alternatives for different processors etc.

When I have a moment I will spend a little more time on some 60 degree IIR settings ... in the mean time I have some Lake LM26 settings that are fantastic; if anyone wants a copy I more than happy to send them on.
 
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Re: 60 Degree DIY Mid Hi

Marjan Milosevic said:
Switching from 90 degree to 60 degree horn will boost the mf/hf about 3-4db because the narrower dispersion.
Click to expand...
And just in "keeping it real", it will only boost those freq over which the size of the horn is large enough relative to the freq wavelength.

In order to keep the same "control" the 60* horn will have to be LARGER than the 90*.

If the same size is maintained-then the control freq will not be as low.

That is why narrow horns HAVE to be larger than wide coverage horns to have the same control
 
Re: 60 Degree DIY Mid Hi

Ivan Beaver said:
And just in "keeping it real", it will only boost those freq over which the size of the horn is large enough relative to the freq wavelength.

In order to keep the same "control" the 60* horn will have to be LARGER than the 90*.

If the same size is maintained-then the control freq will not be as low.

That is why narrow horns HAVE to be larger than wide coverage horns to have the same control
Click to expand...

The horns used in this design satisfy those requirements.
 
Re: 60 Degree DIY Mid Hi

Ivan Beaver said:
And just in "keeping it real", it will only boost those freq over which the size of the horn is large enough relative to the freq wavelength.

In order to keep the same "control" the 60* horn will have to be LARGER than the 90*.

If the same size is maintained-then the control freq will not be as low.

That is why narrow horns HAVE to be larger than wide coverage horns to have the same control
Click to expand...

There you go Ivan - The Frequency response plot at 1 dB per division(!) from about 0-degrees to plus 30-degrees horizontal (light blue line) ... the pattern looks good to me especially through the crossover.

You can also see the LF acoustic crossover point of the 12s i.e. -6 dB at 100Hz LR 24dB.
 

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Re: 60 Degree DIY Mid Hi

Peter Morris said:
There you go Ivan - The Frequency response plot at 1 dB per division(!) from about 0-degrees to plus 30-degrees horizontal (light blue line) ... the pattern looks good to me especially through the crossover.

You can also see the LF acoustic crossover point of the 12s i.e. -6 dB at 100Hz LR 24dB.
Click to expand...

Man, I would look into the horn in that 3-7kHz region. Would you mind sending me the impulse responses, and the sampling rate? I'd be pretty interested in taking a look at them.
 
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Re: 60 Degree DIY Mid Hi

Mark DeArman said:
Man, I would look into the horn in that 3-7kHz region. Would you mind sending me the impulse responses, and the sampling rate? I'd be pretty interested in taking a look at them.
Click to expand...

Hi Mark,

Here is a picture of the impulse response and the manufactures directivity plot. As you can see my measurements match reasonably well. Don't forget my measures were on a 1 dB per division scale, not the usual 5 or 10 dB. At the moment thats about all I have.

Just for interest I have also included a picture of a triangular wave input (bottom) Vs the measured acoustic response (top). I clipped the bottom of it to check some polarity issues I found ... turned out to be an error in the computers sound card not the speaker!
 

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Re: 60 Degree DIY Mid Hi

Peter Morris said:
Hi Mark,

Here is a picture of the impulse response and the manufactures directivity plot. As you can see my measurements match reasonably well. Don't forget my measures were on a 1 dB per division scale, not the usual 5 or 10 dB. At the moment thats about all I have.

Just for interest I have also included a picture of a triangular wave input (bottom) Vs the measured acoustic response (top). I clipped the bottom of it to check some polarity issues I found ... turned out to be an error in the computers sound card not the speaker!
Click to expand...

Yea, I can see it in the polar map as well. Well, if you get a chance to save the impulse out as a csv I would be interested in looking at it. In your original F domain plots you can see the phase deviation on-axis and the corresponding directivity non-linearity in all your off axis plots. It just seems like a pretty large bandwidth, compared to what I'm used to seeing. I just thought it would be an interesting impulse response to look at more closely. I haven't followed this version of your box very closely. Have you tried using some materials to stop modes from forming in the throat? Although there is a dip in the coherence function there also, which would be caused by a reflection which is correlated well with the original stimulus in that bandwidth?
 
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Re: 60 Degree DIY Mid Hi

Mark DeArman said:
Yea, I can see it in the polar map as well. Well, if you get a chance to save the impulse out as a csv I would be interested in looking at it. In your original F domain plots you can see the phase deviation on-axis and the corresponding directivity non-linearity in all your off axis plots. It just seems like a pretty large bandwidth, compared to what I'm used to seeing. I just thought it would be an interesting impulse response to look at more closely. I haven't followed this version of your box very closely. Have you tried using some materials to stop modes from forming in the throat? Although there is a dip in the coherence function there also, which would be caused by a reflection which is correlated well with the original stimulus in that bandwidth?
Click to expand...

Hi Mark,

Love your input J

Interestingly enough there are still a couple of things I wanted to try. One was some dampening material on the horn. It’s made out of a rigid plastic and could have some issues; and some material in the throat to stop modes from forming etc. I suspect for all the reasons you are thinking; it’s just that I have not had time yet.

Any suggestions?

When I get a chance I will save some impulse files.

Thanks
Peter
 
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Re: 60 Degree DIY Mid Hi

Don J Davis said:
Hey Mark,
When I get a chance I'll print out my Driverack settings and email them to you for comparison. The key to tuning these is to get them up in the air outdoors as Peter suggests. Try and find an empty field so you're not dealing with reflections.

I used the 90 deg's this past Saturday in a 500 cap chapel with excellent results. I did have to tweak the gain settings for the VHF for this room. It seemed to require much more gain than when using the 60 deg horns. I also find myself changing all my old channel presets. I'm still getting used to mixing with much lower distortion and a relatively flat system.

Cool comparison BTW!
Click to expand...

Hi Don, nice offer with your settings, thx! Glad to hear the 90's worked so well in the chapel.

I hear you guys, re getting up in the air for testing. I've been trying to test up firing out from a deck....pict below.
I now have a better mic rig than in the pict. I use an 20ft telescoping pole from the ground below that lets me get 10-20ft away from speaker.
Do you guys think this is a decent testing setup? Center of speaker is about 15ft above ground directly below. There is about 18 ft mic to ground with the mic 4 meters from speaker.
Distance to ground seems ok to me...? Is the deck a problem?

deck test.jpg
 
Re: 60 Degree DIY Mid Hi

Peter Morris said:
Hi Mark,

FWIW my 90 degree boxes and 60 degree boxes sound almost identical - the 60 degree version I think is slightly better.

The latest results using FIR filters are absolutely stunning, everyone with out exception is amazed, and if I do say so myself .... I have not heard anything that sounds better :roll:

A couple of questions - are you using 8 or 16 ohm 4594s ? and I assume you are using 8 ohm RCF 12's ?.

With 16 ohm 4594 and 2 x 8 ohm 12" RCF's (in parallel) the mids should be running about 3 to 4 dB less than the HF, for an 8 ohm 4594 6 to 7 dB less ...BUT it depends on the individual processor. The way the PEQs are determined is often different between manufactures .....a problem for any DIY project.

The other issue is my 90 degree boxes are using RCFs and my 60 degree version B&Cs ... so there is variation in the mid processing between the two boxes.

Can you send me what you used and I will check it out. Also check out what Don is using. We all may need to come up with a few different alternatives for different processors etc.

When I have a moment I will spend a little more time on some 60 degree IIR settings ... in the mean time I have some Lake LM26 settings that are fantastic; if anyone wants a copy I more than happy to send them on.
Click to expand...

Hi Peter, Thanks for the ongoing support !

Yes, I am using 8 ohm RCF's in parallel, and 16 ohm 4594s. My mid IIR settings are the ones you posted for the DIY 90, and the HF & VHF settings from your 60 deg post... (snip below as HF example..)
The only major difference in HF /VHF setting from yours, comes from only having 5 eq's per amp channel on the PLD4.5. So I keep polarity the same between the two coax drivers and don't use the last HF PEQ (6.158k, 0.76BW, +5.2db). This seems to level out x-over region ok....?
PM 60 HF.JPG

There were minor variations in freq, and BW, that the PLD amp wouldn't let me dial in exactly, but everything stayed pretty close.

If needing to drop HF and VHF gain 3-4 db for the 60 deg is making sense, I'll let go of scratching my head :) THX again to you and Don.
Now, if I could only find an affordable FIR alternative to the Lake...:D~:-D~:grin:
 
Re: 60 Degree DIY Mid Hi

Jim dee said:
Mark. What was the response of the other people listening?
Click to expand...

Hi Jim, there were just a couple of other guys. I do my best never to speak for others.....I guess my take is they wouldn't be surprised by anything I posted.
And honestly, i didn't press them for any opinions because to my ears it was one of those A/Bs where you know in 15 seconds what you think.
Or at least I knew what I thought :lol:
 
Re: 60 Degree DIY Mid Hi

Art Welter said:
Mark,

The BSS Blu 100 is a fraction of the cost of the Lake, and can do FIR.

Art
Click to expand...

I have never used the BSS, so I no idea how my Lake settingswould transfer (?). The settings are quite complicated and use “normal” IIR filters & crossovers, raised cosine filters, all-pass filters and FIR crossovers.

I’m sure the BSS would work, but you would probably have to come up with your own settings.

As you know using FIR filters by themselves does not improve the sound quality; it just offers you more freedom to fix things.
 
Re: 60 Degree DIY Mid Hi

Hi & thank you Art !

Hi Peter, I've been reading about processing variations in various articles/threads, and really wonder if there is any substitute for learning to measure and know what is being measured.
I'm thinking truly learning dual FFT is what I need more than any particular processor..
That said, could you comment on how well you think the testing setup works, that i tried to elaborate on my most recent post to Don? See any issues?
I'll also post complete IIR setting being used on the 60 deg, just for double check if you have time ...
Thank ya Peter !
 
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