Hey col,
I admire your DIY energy! That's a lot of work, and well done. Your system should pay for itself quickly. Careful not to hijack the thread here though, your system is not going to work for the purpose of this thread.
I agree with Xoc1, a decent digital crossover would do the work of a lot of the outboard gear you're using, and be more versatile. But you're right, it's a personal choice.
technofreak,
I'll play with some 8" drivers + 1x 1" compression driver and see how it looks on the computer. If it'll get the job done with cleaner audio, it's certainly worth considering.
Splaying is a difficult subject due to the variety of venue shapes. I would expect that in the majority of cases (based on my experience), ideal dispersion splaying would give way to just aiming cabinets where they are needed. The coverage area is quite often broken up into different target areas that need to be covered independently. That's the same trouble with using line arrays in clubs. I'll look more closely at horizontal coverage, but I think it would be best to match the horizontal coverage of the waveguides to the 6.5-8" driver coverage -- whatever that is.
..Todd
I admire your DIY energy! That's a lot of work, and well done. Your system should pay for itself quickly. Careful not to hijack the thread here though, your system is not going to work for the purpose of this thread.
I agree with Xoc1, a decent digital crossover would do the work of a lot of the outboard gear you're using, and be more versatile. But you're right, it's a personal choice.
technofreak,
I'll play with some 8" drivers + 1x 1" compression driver and see how it looks on the computer. If it'll get the job done with cleaner audio, it's certainly worth considering.
Splaying is a difficult subject due to the variety of venue shapes. I would expect that in the majority of cases (based on my experience), ideal dispersion splaying would give way to just aiming cabinets where they are needed. The coverage area is quite often broken up into different target areas that need to be covered independently. That's the same trouble with using line arrays in clubs. I'll look more closely at horizontal coverage, but I think it would be best to match the horizontal coverage of the waveguides to the 6.5-8" driver coverage -- whatever that is.
..Todd
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How about MTM with 10" mid and a radial horn. That would allow stacking side by side to increase desired horizontal coverage. Alternatively a bi-radial horn that can still be stacked with minimal interference/lobing.
Alternatively with 8" mid and a smaller angle to allow for more HF drivers for the same horizontal coverage allowing for higher SPL but also higher cost.
I guess synergy/unity horn is out of the question?
I doubt we can go completely diffraction-less and HOM-less and still keep up with SPL requirement so some sort of compromise have to be done.
Alternatively with 8" mid and a smaller angle to allow for more HF drivers for the same horizontal coverage allowing for higher SPL but also higher cost.
I guess synergy/unity horn is out of the question?
I doubt we can go completely diffraction-less and HOM-less and still keep up with SPL requirement so some sort of compromise have to be done.
Back when i was looking at building my own PA speakers. I came up with this idea. its based on the Eighteen sound 6ND430 6" driver which has a very flat frequency response from 100hz to 3K and the 45 degree off axis response is even flatter! So I thought about using 4 of these drivers per cabinet at a 45 degree angle with a waveguide horn in the center with a lot of heavy fiberglass or rockwool around the horn in the middle. this would then have two 12" woofers top and bottom.
I was doing sound for an all girl jam band at the time and I wanted as clean of vocal reproduction as i could. I did not want to use a 15" woofer but figured two 12" drivers would mate better. and i was not looking to get max SPL's out of it as they wanted lower volume. these would be used with a 18" sub cab per side.
I still like the concept...
I was doing sound for an all girl jam band at the time and I wanted as clean of vocal reproduction as i could. I did not want to use a 15" woofer but figured two 12" drivers would mate better. and i was not looking to get max SPL's out of it as they wanted lower volume. these would be used with a 18" sub cab per side.
I still like the concept...
Attachments
I may be late to this thread, I only read first few posts...I made once small PA speakers for a music group at my work, basically bunch of quite good amateurs, playing just for fun, so here is the link, you may find it interesting
Ed Orvisky Audio Pages: PA speakers
the speakers are still in service and they work fine
they would not be anough for large concerts, but enough for small room
ed
Ed Orvisky Audio Pages: PA speakers
the speakers are still in service and they work fine
they would not be anough for large concerts, but enough for small room
ed
An interesting variation might be to take the mid-section of the V-Dosc cabinet as-is (without the 15" drivers) and stack 12" drivers above and below in MTM config. Like Zero Cool's but with the mid-section rotated 90 degr. for wider dispersion and a horn/waveguide to match that dispersion pattern.
I'll have to doodle that up.
One disadvantage I can see immediately is that the mid-highs will end up at shoulder/head height once stacked on the subs, which would not work well. Ideally, you'd want it higher than that -- over peoples' heads.
..Todd
I'll have to doodle that up.
One disadvantage I can see immediately is that the mid-highs will end up at shoulder/head height once stacked on the subs, which would not work well. Ideally, you'd want it higher than that -- over peoples' heads.
..Todd
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A thread about cone driver dispersions and a simple empirical equation to find dispersion at specific frequency or frequency with specific dispersion: At what freq does a 10" do 90 degrees? - Speakerplans.com Forums - Page 1
And a thread about disperion/lobing, a good graph few posts down: Horn dispersion arraying REALLY matter? HELP! - Speakerplans.com Forums - Page 1
At the moment I'm developing a small freeparty system using 6" mids (as for now 1 Eminence Alpha 6, but eventually adding one or possibly two Fane 6-100 per side), small format horns (Celestion HF50, to be replaced by Eminence APT80), 8" low-mids (Fane Sovereign 8-225; 2 per side) and some 15" or 18" subs in the future. X-over shall be 120 Hz and 500 Hz active and 5,5 kHz passive. Small paper cone drivers in midrange sound just amazing, IMO, the real way to go; no usual muddiness, boominess and harsh break-ups of typical 12" and 15" PA speakers (there are exceptions, but they are expensive).
And a thread about disperion/lobing, a good graph few posts down: Horn dispersion arraying REALLY matter? HELP! - Speakerplans.com Forums - Page 1
At the moment I'm developing a small freeparty system using 6" mids (as for now 1 Eminence Alpha 6, but eventually adding one or possibly two Fane 6-100 per side), small format horns (Celestion HF50, to be replaced by Eminence APT80), 8" low-mids (Fane Sovereign 8-225; 2 per side) and some 15" or 18" subs in the future. X-over shall be 120 Hz and 500 Hz active and 5,5 kHz passive. Small paper cone drivers in midrange sound just amazing, IMO, the real way to go; no usual muddiness, boominess and harsh break-ups of typical 12" and 15" PA speakers (there are exceptions, but they are expensive).
One thing to note with the L'acoustics V-DOSC cabinet is the crossover frequencies
15" LF to 7" mid 200 hz Mid to 1.4 HF 1.6Khz.
With an efficient enough HF driver it is possible to crossover to the subs without a lower mid driver.
That is not to say that I liked listening to the V-DOSC system
I heard it at Glastonbury Festival and it was very poor compared with the old Turbosound flashlight system
15" LF to 7" mid 200 hz Mid to 1.4 HF 1.6Khz.
With an efficient enough HF driver it is possible to crossover to the subs without a lower mid driver.
That is not to say that I liked listening to the V-DOSC system
I heard it at Glastonbury Festival and it was very poor compared with the old Turbosound flashlight system
I heard Brubeck live outdoors using V-Dosc and it sounded very nice. But I've also seen V-Dosc mid drivers that were pushed too far. That was probably due to such a low crossover point. I didn't realize they were crossed so low. That explains a lot. It would require using woofers rather than mids, which is a serious departure from what I was planning.
..Todd
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I should have mentioned the system I am building is not a commercial system being built to earn da bux from. This is just something me and my mates use for parties and play with in the workshop. I am not trying to hijack this thread, just contribute to it. Am I the only who is actually building something at the moment instead of just software modeling?
When I started getting units for the rack there wasn't a cheap 4way DSP crossover available. I would have had to buy 2 x Behringer DCX2496 (3way stereo, 4way mono), here in Australia that would have cost around $1000. My rack units to date only cost around $600 secondhand, so it's still cost affective. If I were to start again and go down the DSP path I would probably start a build using the MiniDSP modules.
I don't like the DCX2496 because of the way behringer have implemented the output buffers for the Balanced/Unbalanced versatility. It mangles the sound, especially at high volume levels. If you don't believe me then you don't have to go far beyond this forum for more evidence. Just do a search on DCX2496 and have a look at how many people are modding the units outputs with transformers.
just a comment on using smaller drivers for mids. I found them to beem too much in my last system, they are great when you are standing in front of them, soon as you walk off axis though they loose coverage. I see no problem using a 12" in a mid as long as you don't go too close to the frequency tolerance of the driver.
Also, I have a pair of OB spheroid waveguides (ala Geddes) I use in my HiFi:
MINIRIG Minirig 10″ Mid-High with 10″ waveguide and compression driver
They are very good but I wouldn't use them without the foam plugs, which could be a bit of a hassle in a mobile rig.
I decided to use the Econowave defraction horns (JBL PT waveguides) as I had them in my last rig and they sounded great. Good compromise between short-range coverage and medium to long-throw.
col.
It's pretty much everything under 200Hz. L'Acoustics is very secretive about the processor settings used. There are however several different presets available that change the high pass filter on the 15"s among other parameters. We use XTA's on them and in the presets all settings are locked except for gain. We have created our own settings just to try using a Meyer SIM3 that sounds pretty good though.
You could look at these products for some inspiration about pattern control and sound quality... Danley Sound Labs | Synergy Horns
That's appreciated. I just meant your PA was not a solution to the problem at hand. Your input is valued nevertheless. And this exercise is really just conceptual anyway. I don't have a reason to build a PA unless someone steps up to pay for it (doubtful). And for that matter, I don't have any appropriate modeling software, other than the usual T/S stuff which isn't too helpful for this. ADA Ease looks cool, in case I win the lottery one day.
What are the options now? I have a DCX2496 for my home stereo, but I'm curious about what 8-output products are available.
I would agree with that.
How did you make the foam plug? The foam looks different than the Geddes foam. Is it the same stuff he uses/recommends? I forget what he called it, "reticulated" maybe.
I'll Google those, but I'm afraid of just getting JBL's marketing hype.
..Todd
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