60 Degree DIY Mid Hi - AKA PM60

Re: 60 Degree DIY Mid Hi

FWIW as I understand the 118 dB sensitivity figure for a 4592 was measured on a large 40x 20 horn with a 300Hz cut off. I don't know what they used for the 4594.

BMS – 2242 2” CD Horn– 300Hz, 40 x 20 467 x 467 x 467

I assume they used it because it’s the only horn they manufacture with a 300Hz cut off and the driver was rated to 300Hz.

http://www.bmsspeakers.com/index.php?id=4592nd_curves– these results (about 112 dB) are measured on a more typical 90 x 55 degreehorn http://www.bmsspeakers.com/index.php?id=2230_specification

This is exactly what you would expect … about 6 dB less. It is also exactly in line with most other typical compression drivers. One thing the BMS does have is a very efficient VHF section. To do that they have made a driver with a very high resonant frequency and it will not go below 6kHz
 
Re: 60 Degree DIY Mid Hi

Bennett Prescott said:
As Ivan notes everyone's application is different, so it is critical to test to destruction in order to see which driver can deliver more real world SPL.

Our spec sheets list both AES and "continuous" (2x AES) power, the latter is intended to be used as an amplifier sizing guide: e.g. the DE980TN will likely be well matched by an amplifier that can deliver about 220 watts. Nothing magic about power handing in a compression driver - there's no active cooling, thermal mass is what it is, and the coils are very short and light, so power handing is more or less dictated by the diameter of the coil. Of course some coil suppliers can deliver better power handling than others, we have only been able to qualify two HF coil suppliers in the world.
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And there are failures other than voice coils opening up or diaphragms breaking.

During one of my "testing sessions" (I monitor performance via dual transfer function-so I can see changes in real time), one driver (from a very respected manufacturer) started to show signs of reduced output-a good bit sooner than a different manufacturer driver (being driven from the same source at the same time).

But I kept the test going until I had failure of one of the drivers.

The driver that failed first was not the one that was showing the lowered output.

But at the time of failure, the one with reduced output had a good bit lower actual output than the one that "stopped working" first.

When the drivers cooled down enough for me to take apart, the one with the lowered output had actually melted about half of the"exit areas" in the phase plug. So the exit was essentially sealed off quite a bit-which was the cause for the lowered output.

So the one that "failed first" (and in all fairness was rated at lower power), actually had a higher output longer than the one that "kept working" longer. But the one that kept working-would never come back to original performance-because of the sealed off area.

So things are not always as they seem.

Once again-you can't describe something complicated, with a "simple" number.
 
Re: 60 Degree DIY Mid Hi

Ivan Beaver said:
And there are failures other than voice coils opening up or diaphragms breaking.

During one of my "testing sessions" (I monitor performance via dual transfer function-so I can see changes in real time), one driver (from a very respected manufacturer) started to show signs of reduced output-a good bit sooner than a different manufacturer driver (being driven from the same source at the same time).

But I kept the test going until I had failure of one of the drivers.

The driver that failed first was not the one that was showing the lowered output.

But at the time of failure, the one with reduced output had a good bit lower actual output than the one that "stopped working" first.

When the drivers cooled down enough for me to take apart, the one with the lowered output had actually melted about half of the"exit areas" in the phase plug. So the exit was essentially sealed off quite a bit-which was the cause for the lowered output.

So the one that "failed first" (and in all fairness was rated at lower power), actually had a higher output longer than the one that "kept working" longer. But the one that kept working-would never come back to original performance-because of the sealed off area.

So things are not always as they seem.

Once again-you can't describe something complicated, with a "simple" number.
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Exactly, it’s not straight forward.

While I wanted as much SPL on a stick as I could get, I also wanted extreme "studio monitor" audio quality; to ensure that I can get the most out of the DIY, it’s running 3-way active with separate limiting on each band, and in the case of the Lake processor, some very cleaver limiting.

I believe you using a similar driver in your SH96HO and crossing them over at about 1500Hz (?) The SH96HO is either passive or bi-amped 15” to 6”+ CD (?).

I must say Ivan, this is a very impressive box and I’m staggered at the amount of HF and VHF you are getting with one HF driver especially without running limiters on individual bands.
https://www.youtube.com/watch?v=oA-7ZplZF7M

From what I have seen I suspect the 4594, even though I am crossing at 630 – 700Hz will be a good match for the DIY.
 
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Re: 60 Degree DIY Mid Hi

Thanks guys, I didn't understand everything in your post Peter but thanks for the clarification! What I'm trying to understand is if one could use the B&C 4" vc CD(or the other ones you listed) and get similar performance except from sacrificing a bit of air compared to the BMS(I think the 'air' frequencies are a bit overrated in PA business anyway, especially in EDM), or if there is more to it.

Does your sketch for example explain that the BMS lead to better transient response due to increased peak handling compared to non-coax CD? OTOH if this is the case, wouldn't it be kind of obsolete if you can't provide separate RMS and peak limiter for the system?
 
Re: 60 Degree DIY Mid Hi

Hi everybody. Another lurker surfacing! Great project here, I have for a while now been looking for a diy top box to go with some Othorns. Thinking this design will be the solution. Which leads me to a question what sort of power will the 4 12 inch drivers be wanting? Would a QSC PLX3002 be enough ???

Hat's off to Peter Morris. It's always wonderful to see somebody happy to share like this! Doesn't happen enough in this world!
 
Re: 60 Degree DIY Mid Hi

Jim dee said:
Hi everybody. Another lurker surfacing! Great project here, I have for a while now been looking for a diy top box to go with some Othorns. Thinking this design will be the solution. Which leads me to a question what sort of power will the 4 12 inch drivers be wanting? Would a QSC PLX3002 be enough ???

Hat's off to Peter Morris. It's always wonderful to see somebody happy to share like this! Doesn't happen enough in this world!
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A PLX3002 on the DIY would certainly keep up with 1 x Othorn preside. If you really want to get the absolute maximum out of the DIY it would be nice to have something a little bigger.
 
Re: 60 Degree DIY Mid Hi

Ossian Ott said:
Thanks guys, I didn't understand everything in your post Peter but thanks for the clarification! What I'm trying to understand is if one could use the B&C 4" vc CD(or the other ones you listed) and get similar performance except from sacrificing a bit of air compared to the BMS(I think the 'air' frequencies are a bit overrated in PA business anyway, especially in EDM), or if there is more to it.

Does your sketch for example explain that the BMS lead to better transient response due to increased peak handling compared to non-coax CD? OTOH if this is the case, wouldn't it be kind of obsolete if you can't provide separate RMS and peak limiter for the system?
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Short answer, I don't really know, there are very few 1.4" exit - 4" diaphragm horns around and I have not tried any. B&C have always made great drivers, so it will be interesting to see what the 1090 is like.

I have tried a 3" diaphragm 18sound CD http://www.eighteensound.it/PRODUCTS/Products/CatID/3/ProdID=151#.VcmfdGkiOos and it was not happy going loud below 800Hz - the lowest crossover frequency recommended by the manufacturer. It did however sound very nice on the RCF HF950 horn crossed at 900Hz.

As it did not go low enough, I did not test it in this DIY.

I am aware that RCF crosses their ND950 at 650Hz in their TT5a, but the ND950 does not sound as nice as the BMS driver.
 
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Re: 60 Degree DIY Mid Hi

Peter Morris said:
Hi Steve,

Nice to hear from you. Will you be a Integrated this year? [...]
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Hi Peter,

Unfortunately I won't be at Integrate this year, however, I am planning on next year.

I will be there just as a punter though. Haven't yet decided when I'm going. When are you going? (If you are)

Thanks for the details on stands, I'll chase them up…
 
Re: 60 Degree DIY Mid Hi

The DIYs were designed to be used as a single box on a stick. They are not designed as part of an array like L-Acoustic Arc’s, but they seem to work quite well as apair. As you would expect it is necessary to modify the settings a little to get the best results.

With the back of the boxes touching and parallel, the optimum splay angle seems to be about 45 to 50 degrees between boxes.

… anyway we did our first gig with the 60 degree boxes today - two per side flown above two double 18s. It was tricky, no sound check, lots of different acts and lots of musicians. Probably the worst gig to pick to try and dial-the-system-in for the first time but we got there with a few minor adjustments J

A couple of Facebook comments I found:

FOH Engineer - “On the Midas Pro 2 today with Peter Morris latest speaker system. This rig sounded AMAZING!!!!!!!”

Event organizer - “I gotta say, I thought the sound was just incredible..You outdid yourselves this year... and I had many, MANY comments saying thesame... thank you both for a great job today”



 
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Re: 60 Degree DIY Mid Hi

Peter Morris said:
They are not designed as part of an array like L-Acoustic Arc’s, but they seem to work quite well as a pair.
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Excellent to hear Peter! What size outdoor area do you feel 2 a side splayed as you suggest will cover at reasonable level? 45-50 deg sounds like a lot of splay.
What sort of minor adjustments did you have to make, EQ?
Any chance you had time for photos or video? Sounds like you had your hands full.

I got sidetracked by another project, but my second set is underway.
 

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Re: 60 Degree DIY Mid Hi

Don J Davis said:
Excellent to hear Peter! What size outdoor area do you feel 2 a side splayed as you suggest will cover at reasonable level? 45-50 deg sounds like a lot of splay.
What sort of minor adjustments did you have to make, EQ?
Any chance you had time for photos or video? Sounds like you had your hands full.

I got sidetracked by another project, but my second set is underway.
Click to expand...

I'm actually very jealous that you're able to build with the angled sides and even with CNC it's just too much of a pain to do for me.
 
Re: 60 Degree DIY Mid Hi

Don J Davis said:
Excellent to hear Peter! What size outdoor area do you feel 2 a side splayed as you suggest will cover at reasonable level? 45-50 deg sounds like a lot of splay.
What sort of minor adjustments did you have to make, EQ?
Any chance you had time for photos or video? Sounds like you had your hands full.

I got sidetracked by another project, but my second set is underway.
Click to expand...

Sorry for the delay in responding. I still want to do a bit more work on the settings for two boxes.

Putting two boxes together cause a few issues, as it does with all point source boxes unless they have been designed to operate as one box like L-Accoustic ARC’s as I mentioned above.

Unfortunately we were not able to do a sound check. The best we could do was play soft background music. There was not even an opportunity before the show to try it out L so to speak and get some idea of what the system is capable of.

The first band had 5 vocals, 7 brass, drums, guitar, bass,keys and 7 monitor sends from FOH … and more or less no sound check! It was combat audio at its best.

The show was for the Vietnam Veterans ( Long Tan day https://en.wikipedia.org/wiki/Battle_of_Long_Tan) , so the SPL was also limited during the show, however we did turn it up a couple of times. For what was essentially two stick mountable speakers per side, the output seemed ridiculous.

I did make a recording of John Schumann who is the singer in this video https://www.youtube.com/watch?v=Urtiyp-G6jYon my iPhone singing his original 1983 hit some 32 years later. You can compare a live iPhone mic recording to the1983 original / YouTube reproduction.
https://www.youtube.com/watch?v=GQBZ6T1QC8g&feature=youtu.be
 
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Re: 60 Degree DIY Mid Hi

Hi Don,

Here is a screen shot of the EQ overlay I have come up with for two boxes - its what I add to the initial EQ. It seemed to work with a splay angles between 35 and 47.5 degrees. Although the boxes have a nominal coverage pattern of 60 degrees, if you splay them 60 degrees to give you 120 degrees of coverage there is a noticeable whole in the pattern

This is still work in progress but as you can see the main problem is a peak around 200Hz and the need for a bit more VHF.
 

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Re: 60 Degree DIY Mid Hi

Peter Morris said:
Hi Don,

Here is a screen shot of the EQ overlay I have come up with for two boxes - its what I add to the initial EQ. It seemed to work with a splay angles between 35 and 47.5 degrees. Although the boxes have a nominal coverage pattern of 60 degrees, if you splay them 60 degrees to give you 120 degrees of coverage there is a noticeable whole in the pattern

This is still work in progress but as you can see the main problem is a peak around 200Hz and the need for a bit more VHF.
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Thanks for sharing that Peter.

Interesting that the VHF needs that much of a shelf. When I tested mine one a side there seemed to be plenty of VHF.

On the 200 build up, I noticed during testing mine that when I lowered the box from 4 meters down to about 2.75 there was a noticeable increase at 150-200hz range. I'll be using them this weekend in 500 cap chapel and will try and get Smaart out if I have time.

BTW thank you for doing the event for your Nam vets. Brave men indeed!
 
Re: 60 Degree DIY Mid Hi

Don J Davis said:
Thanks for sharing that Peter.

Interesting that the VHF needs that much of a shelf. When I tested mine one a side there seemed to be plenty of VHF.

On the 200 build up, I noticed during testing mine that when I lowered the box from 4 meters down to about 2.75 there was a noticeable increase at 150-200hz range. I'll be using them this weekend in 500 cap chapel and will try and get Smaart out if I have time.

BTW thank you for doing the event for your Nam vets. Brave men indeed!
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The HF boost (+3 dB shelf) was a compromise. I averaged the level across the whole coverage area of the two boxes (per side). In some spots it’s a little hot and in others a little low.

Above about 8 kHz the horizontal pattern drops below 50 degrees, so you get a bit of a dip in the middle of the two boxes. The other EQ changes are very minor. Your settings are likely to be slightly different so these may not be appropriate.

Good luck with you gig this weekend :)~:-)~:smile:

FWIW if you are using Smaart still rely on your ears, flat with Smaart will not necessarily sound that nice.
 
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Re: 60 Degree DIY Mid Hi

Hi, I have another question regarding amplification. I am wondering if a Lab 20:8x would be sufficient to handle the bms's power needs. Would the single 250w channels be sufficient or would it need to bridged to handle the job?

Or do I need something more powerful?

Also, can anyone suggest what might be some good(cheaper) 8 channel processing to search for. Things seem to get very pricey when looking for 8 channel processing.( I hope this is not to off topic, let me know if it is and I can start a thread elsewhere).

Sorry for only asking questions. Hopefully later on I will have something to give back.
 
Re: 60 Degree DIY Mid Hi

Jim dee said:
Hi, I have another question regarding amplification. I am wondering if a Lab 20:8x would be sufficient to handle the bms's power needs. Would the single 250w channels be sufficient or would it need to bridged to handle the job?

Or do I need something more powerful?

Also, can anyone suggest what might be some good(cheaper) 8 channel processing to search for. Things seem to get very pricey when looking for 8 channel processing.( I hope this is not to off topic, let me know if it is and I can start a thread elsewhere).

Sorry for only asking questions. Hopefully later on I will have something to give back.
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If you can live with the badge, the DCX2496 units are excellent cheap units for this kind of processing.

As far as amp power goes, I wired the HF and VHF sections of the BMS driver on the 18sound horn to my home stereo receiver to play with something a bit and even with those maxing out at about 80watts I wasn't really disappointed so I'd estimate that as long as that's RMS and they've got a bit of extra swing to them you'll be perfectly fine.
 
Re: 60 Degree DIY Mid Hi

Max Warasila said:
If you can live with the badge, the DCX2496 units are excellent cheap units for this kind of processing.

As far as amp power goes, I wired the HF and VHF sections of the BMS driver on the 18sound horn to my home stereo receiver to play with something a bit and even with those maxing out at about 80watts I wasn't really disappointed so I'd estimate that as long as that's RMS and they've got a bit of extra swing to them you'll be perfectly fine.
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Yes those are really really really cheap. I don’t have a problem spending three times that much or a little more especially when they actually can do the 8 way processing I want/need(I think). Seen an XTA unit on ebay , serious money and serious gear. Maybe I actually need that. Will suss this out in time. Think I best get my own thread regarding some of my questions!

Thanks for the reply.
 
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