New DIY Mid High (90deg) - AKA PM90

[Eric Cagle]

Re: New DIY Mid High

Great thread Peter and Guys. I am considering building a pair of these as well. This is exactly the cabinet I have been looking for to shed almost 200lbs each from one of my ageing trap rigs I still use for certain applications. Sound quality, output, cost, and weight in that order have always been the determining factors for me. Now that I am less young and agile as I used to be, weight is now the main factor I have been looking at the last 2 years for a replacement cabinet. PM sent to Jeffrey for the group buy. Thanks for sharing Peter!

 

[Peter Morris]

Re: New DIY Mid High

Hi Peter,

If you think more power handling is needed I draw your attention to our new 12NDL88, versions of which you may start to see as early as Pro Light & Sound in April: http://www.bcspeakers.com/products/lf-driver/12-0/12ndl88

Many thanks Bennett - the 12NDL88 was probably the first speaker I looked at when I started the project. Unfortunately its design may not suit this horn according to the model I made. The cone was too heavy and rolled off the higher frequencies more than I liked. It was about 6dB down at 700Hz compared to the 12NDL76 and the RCF. Similarly I looked at some of the BMS drivers and found the same issue.

The problem for any DIY is that you can't afforded to test all the driver and box design permutations and variations. This is where this community is such a great resource.

 

[Spenser Hamilton]

Re: New DIY Mid High

Hi Peter,

Awesome work so far on the DIY MH. I have been following along since the beginning of the thread. I'm fairly close to committing to build at least four of these boxes for our own use. Since I'm contemplating this, I'm also willing to help coordinate a group buy for the BMS drivers and possibly other logistics to see these cabinets State side.

Everyone,

I've spoken with Jack Arnott from Assistance Audio on a group buy to leverage our SFN DIY buying power. Here's the rough terms of how it could work:
Base price of the the BMS 4594HE is ~$785.00 each plus shipping.
If we can do 13+, we can drop that price to ~$550 each plus shipping (an approximately 30% discount).

***SNIP***

Thank you,

Jeff

@Jeff Let me know if this offer extends to those of us up north, if so count me in for a pair.

@Peter Few questions/thoughts:
a) The RCF HF64, I assume this was ruled out due to not having adequate pattern control down low? Conversely the HF6040 was ruled out due to being wayyyy too big. Regardless, the 18 Sound option is quite affordable even at street pricing.
b) Is it worth trying the 12NDL76? I'm willing to be the guinea pig if you think it's got a chance of working.
c) Re: Trap vs. Rectangular box. I assume we won't be able to tight-pack these even with angled sides, and those mid-horn panels look like they will pretty tough to cut and fit. I wonder if the benefits will outweigh the added complexity.

Finally, @Jack, will we be able to package the passive crossover with these driver orders?

 

[Jack Arnott]

Re: New DIY Mid High

Finally, @Jack, will we be able to package the passive crossover with these driver orders?

Short answer, yes. Cost is $19.50 at this discount.
Also please note that the cost is including freight to Jeff, but not shipping (or shipping materials) from Jeff to all y'all.

 

[Peter Morris]

Re: New DIY Mid High

@Jeff Let me know if this offer extends to those of us up north, if so count me in for a pair.

@Peter Few questions/thoughts:
a) The RCF HF64, I assume this was ruled out due to not having adequate pattern control down low? Conversely the HF6040 was ruled out due to being wayyyy too big. Regardless, the 18 Sound option is quite affordable even at street pricing.
b) Is it worth trying the 12NDL76? I'm willing to be the guinea pig if you think it's got a chance of working.
c) Re: Trap vs. Rectangular box. I assume we won't be able to tight-pack these even with angled sides, and those mid-horn panels look like they will pretty tough to cut and fit. I wonder if the benefits will outweigh the added complexity.

Finally, @Jack, will we be able to package the passive crossover with these driver orders?

A couple of points / answers –

- I used an RCF HF950 horn. Its their newest horn flare and is used in their new TT2a and TT5a
- All of the components I used are amongst the very best you can buy.
- The HF950 has a 400 Hz cut off frequency and reasonable directivity down to about 1000Hz.
- The HF64, as you noted does not have the pattern control down as low as the 950 or 1464 nor is its cut off frequency as low.
- The HF6040 is 2” and is too big.
- The 18sound XT1460 and the HF950 are quite affordable.
- The XT1464 will require the box to be slightly deeper … 10 – 20 mm
- You could make the box trapezoidal … but it would be almost impossible to make as a DIY. For the 60 degree version I’m planning to build a square box and cut the back corners off. This should make it look a little smaller and it should be a little better when arraying 2 boxes.
- The 12NDL76 SIMs very well. When I have some spare time I will try them.

 

[Peter Morris]

Re: New DIY Mid High

I did some work/measurements with box flown about 3.5m in the air. It was too windy yesterday and I will need to do them again but it was worth posting the results. The response is shown with the desks high pass filter in. Flying the boxes to take a measurement is soooo much better than trying to do a plot near the ground. The results also seem to voice well.

FWIW I also have posted some of my early SIMs - Horn Response will calculate directivity and SPL, but not for this box. Only "standard" horns without bends and ports. The results should however give some indication of what to expect.

I have also shown some square wave plots (100, 200, 500, 1000 & 4000) - because the phase and amplitude are not both flat below 300Hz there is some wave form shape distortion on the 100Hz and 200Hz plots ... but still exceptional.

Also note the 4.0KHz plot - this is basically a Fourier series where you can only see 2 sine waves - 4.0 Khz sine wave + 12KHz sine wave. The 20.0 Khz sine wave (and above) component you won't see ... so its more or less about as good as it gets. Systune does not display a 4KHz square wave form the signal generator any better.

 

[Max Warasila]

Re: New DIY Mid High

Oh look, Australian sun, sky, and foliage. Such a departure from the stunning grey chill around here this time of year.

Right - great box. Almost forgot. :razz:

 

[Spenser Hamilton]

Re: New DIY Mid High

A couple of points / answers –

- I used an RCF HF950 horn. Its their newest horn flare and is used in their new TT2a and TT5a
- All of the components I used are amongst the very best you can buy.
- The HF950 has a 400 Hz cut off frequency and reasonable directivity down to about 1000Hz.
- The HF64, as you noted does not have the pattern control down as low as the 950 or 1464 nor is its cut off frequency as low.
- The HF6040 is 2” and is too big.
- The 18sound XT1460 and the HF950 are quite affordable.
- The XT1464 will require the box to be slightly deeper … 10 – 20 mm
- You could make the box trapezoidal … but it would be almost impossible to make as a DIY. For the 60 degree version I’m planning to build a square box and cut the back corners off. This should make it look a little smaller and it should be a little better when arraying 2 boxes.
- The 12NDL76 SIMs very well. When I have some spare time I will try them.

Cheers Peter! I'm going to try to sit down with Sketchup this week and try to work through what you have posted, let me know if you get a chance to measure the horn panels in more detail.

Still waiting for an answer from Jeff, would love to get in on this...

 

[Jeffrey Knorr]

Re: New DIY Mid High

Cheers Peter! I'm going to try to sit down with Sketchup this week and try to work through what you have posted, let me know if you get a chance to measure the horn panels in more detail.

Still waiting for an answer from Jeff, would love to get in on this...

Hi Spenser,

As long as you'll cover the shipping and anything import related on the CA side (AND it doesn't violate Jack's agreements), you're more than welcome!

Jeff

 

[Jack Arnott]

Re: New DIY Mid High

Hi Spenser,
As long as you'll cover the shipping and anything import related on the CA side (AND it doesn't violate Jack's agreements), you're more than welcome!
Jeff

I ship to United States, Canada, and anywhere else that does not have a distributor.
Also, I am shipping to you, Jeff, what you do with it after that is your business.
So good to go either way.

 

[Peter Morris]

Re: New DIY Mid High

Cheers Peter! I'm going to try to sit down with Sketchup this week and try to work through what you have posted, let me know if you get a chance to measure the horn panels in more detail.

Still waiting for an answer from Jeff, would love to get in on this...

Hi Spenser,

I actually did this trick with the outer horn (below). I spaced the cuts at increasing intervals so I could approximate the exponential curve I needed. Having said that its not that critical, the difference between a conical horn, an exponential horn, and an exponential horn made of conical sections is not that much.

The other thing to note is that if you make a 60 degree version you will need to make it a little deeper. Also note the clearance between the compression driver and the 12" is very small. It fits between the spokes of the 12" frame - you must check this all fits.

 

[Simon Coffin]

Re: New DIY Mid High

Hi Peter,

Once again, great job. Since quite a few of us are interested in building this cabinet as soon as plans are formalized, would you be willing to develop settings for a variety of DSPs? This would help with cross rentals and better establish a standard voicing for the cabinet. Ideally, the only difference would be the amp gain settings.

Which makes me curious how everyone intends to drive and process them? Bi-amp, tri-amp, DSP, amps??

Ciao
Simon

 

[Rob Timmerman]

Re: New DIY Mid High

Hi Peter,

Once again, great job. Since quite a few of us are interested in building this cabinet as soon as plans are formalized, would you be willing to develop settings for a variety of DSPs? This would help with cross rentals and better establish a standard voicing for the cabinet. Ideally, the only difference would be the amp gain settings.

That seems like a fair bit of work. More reasonable would likely be to publish the electrical transfer function of the processing, to allow a user to develop equivalent settings for his own DSP platform. Users could publish their settings and associated transfer functions to expand the library of DSP platforms for the loudspeaker.

 

[Max Warasila]

Re: New DIY Mid High

That seems like a fair bit of work. More reasonable would likely be to publish the electrical transfer function of the processing, to allow a user to develop equivalent settings for his own DSP platform. Users could publish their settings and associated transfer functions to expand the library of DSP platforms for the loudspeaker.

I agree. I feel like that is beyond the scope of Peter's work and shouldn't be asked of him. Letting us know what his settings are is one thing. Doing our work for us is another.

 

[Peter Morris]

Re: New DIY Mid High

What I will do is post some IIR settings for the Lake, but please be aware that different processors define their PEQ filters differently. I have not built the 60 degree version yet, accordingly I don’t have any settings for them yet.

I the mean time I will post some screen shots of the current Lake FIR settings.

It may take a little while for me to get around to it - its “Mad March” in South Australia; the weather is great and there are so many music events happening … it’s crazy.

I rarely work as a sound engineer and actually mix these days; however I used the DIYs on a small show last night. It was a traditional Italian folk band from Italy. Nobody spoke English which made things a little tricky. One of my friends had to translate almost everything.

The venue was quite small holding about 300 – 400 people seated for dinner.

The band gave me one of their CDs, I took it home before the show and had a listen to ensure got the balance a flavour of what they wanted … The DIYs sounded fantastic, the live performance sounded better than the CD. It was clear, detailed and preserved the timbre of all the instruments.

After the show the band came up gave me a pat on the back … Bravo Bravo … so I think they like what I did.

My friend returned to help me with the load out. He spoke to the band and they were over the moon, apparently it was the best sound they had since they have been in Australia, they said the instruments sound very natural … perfetto! (I don’t know what their reference point was however)

…anyway, although he does know it yet, Darren who posted earlier in this thread will be using them next week … hopefully he will like them.

 

[Peter Morris]

Re: New DIY Mid High

The FIR settings are quite complex.:?~:-?~:???: In comparison the IIR setting are relatively simple, however I want to do them again with the box flown before I post them.

These settings produce a flat amplitude response from about 80Hz to 20 KHz. The phase response flat from 300 Hz up.

In addition I have added a some group EQ -2 to -3 dB centred at 3.1 KHz and a very gentle shelving filter +3dB at 100Hz tapering off to zero at about 500 Hz. This is a personal "taste" EQ, so apply as you like.

Note: the Mid and Hi amp gains are 26 dB, the low gain was set to 35 dB. LM 26 FIR time 2.5ms

 

[Mark Wilkinson]

Re: New DIY Mid High

Hi Peter, newbie here. Many Thanks for a great thread/project. And thanks to the group... especially all those helping this project get a toehold..

I'm strongly considering giving a pair of these a try.

Any idea how you think they might work on top of 4 labhorns?

thx again, Mark

 

[Riku Ylinen]

Re: New DIY Mid High

Peter,

Good job and thanks for sharing all this with us!

Could you easily post a measurement plot of raw responses of the drivers? Taken with the same voltage/loudspeaker position/mic position, so that their sensitivity differences would be pretty much absolute. Or have you posted something like this previously, I couldn't find? All this if you already have taken and stored those curves on your computer, don't run to the field with your equipment for me...

I have some 4594 drivers (not HE, yet) and 950 horns but haven't built the 12" portion of your box, instead I've been working with some smaller 12" horn designs ( drivers Beyma 12P1000ND and RCF MB12N405). Pretty much like Seeburg K24.

And now I'd like to know how much I´m lacking sensitivity compared to your more ideal 12" horn...

Thanks!

Riku

 

[Peter Morris]

Re: New DIY Mid High

The ratio of subs to tops will of course depends on what type of music you are playing, but I don't think one DIY a side would keep up to 4 Lab Horns per side. As a GUESS one DIY would keep up with 2 Lab horns a side. Two 60 degree DIYs for about 3 Lab horns per side. Once you get 4 to 6 Lab horns a side, the horns start to work properly and you get a lot more efficiency and SPL ...

The DIY mid-hi is designed be a "super" speaker on a stick not part of a point source array like EAW's KF750s or Nexo's Alpha. I suspect the 2 x 60 degree cabinets would work perfectly well and provided 90 - 120 degrees of coverage. I also suspect that you could fly 2 over 2 of the 60 degree version.

 

[Mark Wilkinson]

Re: New DIY Mid High

Thanks Peter, your comments all make sense. And I apologize for not giving more info....4 labhorns is all I have...they represent my one and only foray into DIY.
I am looking for a "super speaker on a stick" just as you describe the design goal. With either 2 Labhorns per side in stereo, or the 4 blocked together in mono sub.

I have been using meyer upa-1p's as tops, and they sound great until pushed. But when pushed, an upper bass/ lower mid, hole is obvious, making me raise x-over freqeuncy above 80 hz. 80hz is where all sounds best at lower levels.

I'm hoping your design solves all that !! Many thx again, Mark