You've got this risk with everything.
As i use computer for 25 y, evolved from win95 to 10 along the way and used them for my work in studio i know stable systems are possible to implement.
EG my main 'recorder' run under xp and never crashed ever with 32i/o, plug ins and all. Of course the os is optimised and it is a recorder so nothing other than soft and driver on it.
For mixing/mastering i use win10 and it is stable too...and drive my dsp through aes. Never had an issue till now. But yes sh.t happen sometime. There is always a risk.
As i use computer for 25 y, evolved from win95 to 10 along the way and used them for my work in studio i know stable systems are possible to implement.
EG my main 'recorder' run under xp and never crashed ever with 32i/o, plug ins and all. Of course the os is optimised and it is a recorder so nothing other than soft and driver on it.
For mixing/mastering i use win10 and it is stable too...and drive my dsp through aes. Never had an issue till now. But yes sh.t happen sometime. There is always a risk.
no the risk is absolutely unacceptable.
i can't order a bunch of drivers from Europe hook them up to a a multi-kilowatt array of Crown and QSC amps and then have it all blow up ...
i can't order a bunch of drivers from Europe hook them up to a a multi-kilowatt array of Crown and QSC amps and then have it all blow up ...
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Polypropylene caps on the tweeters, offline Linux box, UPS battery and build confidence with 5W. You might not want to upgrade.
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sounds complicated ...
i will have caps on the compression drivers but other drivers could get blown too ...
i will have caps on the compression drivers but other drivers could get blown too ...
A life with zero risk is a fantasy.
Computer can crash, a component can fail in your poweramp and expose things to 60v dc... a dsp within an amp ( iow a computer) can crash too...
I mean you have a bias here. But i understand, i'am biased on things too. That said with multiple members sharing same experience even if anecdotal evidence there is a pattern at work.
Not sure your concerns are valid from my pov.
Computer can crash, a component can fail in your poweramp and expose things to 60v dc... a dsp within an amp ( iow a computer) can crash too...
I mean you have a bias here. But i understand, i'am biased on things too. That said with multiple members sharing same experience even if anecdotal evidence there is a pattern at work.
Not sure your concerns are valid from my pov.
There is a number of members here using their gear this way and even if the risk exist no one reported catastrophic failure. I fryed some drivers in my life but not because of a crashing computer, dsp or anything digital. Through analog gear however it happened (live act, someone plugin a mic with phantom power on while everything open wide in the signal path... instantaneous boom, all sub losts, people suffers heart attack or run away as fast as possible believing a bomb exploding. I'm halfway joking 😉 ).
well as i said i'm just going to design the acoustical part of the system assuming unlimited DSP capability will eventually become available and not concern myself too much with what functions are available in which product at the given moment ...
i will also assume unlimited amplifier power available as well ...
it's just going to be about aligning drivers and enclosures with ports and horns and that kind of stuff ...
the rest can be fixed later ...
try to shoot for about 5 ohms in the treble and 3 ohms in the bass ... i know people seem to think there is something wrong with 2 ohms but i think it is superstition ... there is no fundamental reason why you couldn't have even a 1/2 ohm load ... you would simply need to have more stuff in parallel inside the amp to account for it ...
there is every reason to assume that a more powerful amp expects more loads connected in parallel and is ready to handle it ...
maybe hooking up a 2 ohm load to a 50 watt amp is not bright but a 5,000 watt amp should probably be able to handle it ...
i will also assume unlimited amplifier power available as well ...
it's just going to be about aligning drivers and enclosures with ports and horns and that kind of stuff ...
the rest can be fixed later ...
try to shoot for about 5 ohms in the treble and 3 ohms in the bass ... i know people seem to think there is something wrong with 2 ohms but i think it is superstition ... there is no fundamental reason why you couldn't have even a 1/2 ohm load ... you would simply need to have more stuff in parallel inside the amp to account for it ...
there is every reason to assume that a more powerful amp expects more loads connected in parallel and is ready to handle it ...
maybe hooking up a 2 ohm load to a 50 watt amp is not bright but a 5,000 watt amp should probably be able to handle it ...
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It's not supersition given a great majority of amps aren't designed to be able to drive 2 ohm loads
True. Here's a snip from a QSC whitepaper https://www.qsc.com/resource-files/whitepapers/q_wp_sys_amp_flexibleamplifiersummingtech.pdf
Shows how paralleling channels in PLD or CXD amps can drive very low ohm loads.
Not necessarily. It all depends on what impedance range the powerful amp was designed for...
Note for instance, the different wattage peaks vs impedance in the above snip.
well the only reason anybody uses impedances more than 2 ohms at all is to reduce losses over long speaker cable runs
JBL mostly sells 8 ohm woofers for example but their active speakers have 2 ohm woofers inside because the speaker cables are not more than 2 feet long and don't have any losses to speak of
this is also why car audio subwoofers are often 2 ohms as well because the amp is usually less than 3 feet away from the subwoofer
on other hand if you have an array hanging 100 feet in the air over some stadium the cables can get pretty long and losses significant and you will want high voltage and high impedance to minimize losses which are proportional to current squred
so actually contrary to popular belief 2 ohm loads are more efficient to drive provided that amp is designed for it and cables are short
then there is an issue of power level and voice coil wire diameter ... compression drivers have lightweight voice coils wound with thinner wire and taking less power compared to woofers ... this naturally lends them to higher impedances.
i mean amplifiers more or less all run in the same voltage range, it's just that current goes up for bigger amps. so you have woofers available in 8 and 4 ohms but tweeters in 8 and 16 ohms and headphones in 16, 32, 64 and all the way up to 300 ohms.
maybe i shouldn't even think about impedances at all. maybe as long as i don't mix car audio speakers with prosound amps and vice versa it will all work out. although TC Sounds LMS was a car audio speaker and i had it driven by PLX 2402 with the two voice coils in series and the amp bridged.
so the impedance an amp expects comes down to power and application. higher power amps generally expect to see lower impedance but also amps designed for shorter cable runs expect to see lower impedance as well.
amps that have higher voltage swing generally cost more and what you're paying for is ability to use long cable runs. it is more cost effective to use amps with lower voltage swing and 2 ohm loads as long as your cables are not too long.
JBL mostly sells 8 ohm woofers for example but their active speakers have 2 ohm woofers inside because the speaker cables are not more than 2 feet long and don't have any losses to speak of
this is also why car audio subwoofers are often 2 ohms as well because the amp is usually less than 3 feet away from the subwoofer
on other hand if you have an array hanging 100 feet in the air over some stadium the cables can get pretty long and losses significant and you will want high voltage and high impedance to minimize losses which are proportional to current squred
so actually contrary to popular belief 2 ohm loads are more efficient to drive provided that amp is designed for it and cables are short
then there is an issue of power level and voice coil wire diameter ... compression drivers have lightweight voice coils wound with thinner wire and taking less power compared to woofers ... this naturally lends them to higher impedances.
i mean amplifiers more or less all run in the same voltage range, it's just that current goes up for bigger amps. so you have woofers available in 8 and 4 ohms but tweeters in 8 and 16 ohms and headphones in 16, 32, 64 and all the way up to 300 ohms.
maybe i shouldn't even think about impedances at all. maybe as long as i don't mix car audio speakers with prosound amps and vice versa it will all work out. although TC Sounds LMS was a car audio speaker and i had it driven by PLX 2402 with the two voice coils in series and the amp bridged.
so the impedance an amp expects comes down to power and application. higher power amps generally expect to see lower impedance but also amps designed for shorter cable runs expect to see lower impedance as well.
amps that have higher voltage swing generally cost more and what you're paying for is ability to use long cable runs. it is more cost effective to use amps with lower voltage swing and 2 ohm loads as long as your cables are not too long.
In the midrange thread, you specify you want to "write the book". No matter how you combine drivers, horns, subs etc, someone has done similar.
What I have yet to see is a full range good sized MEH/Synergy horn that don't comprimise on horn/WG profile, mouth termination, driver selection and implementation. Most DIY covers 80-120 Hz and up. "A for Ara" has some serious builds but a bass horn att the low end. Mark100 has thoughs about cone midrange superior to compression driver (I believe A for Ara use coaxial drivers, might be wrong though)
What is left to write:
True full range MEH as large as your doors will allow. The directivity of a 7' horn will make the (mid) bass sound and feel like a true punch yet still coherent. All drivers sealed for perfect impulse response. 12-18" woofers, they are fireing through a hole anyway, so better use smaller but more when needed to keep piston movement.
Danley has quite a few Synergies for pro sound, but in domestic environment, a single compression driver is enough. Better to focus on quality than massive SPL.
Thoughs?
What I have yet to see is a full range good sized MEH/Synergy horn that don't comprimise on horn/WG profile, mouth termination, driver selection and implementation. Most DIY covers 80-120 Hz and up. "A for Ara" has some serious builds but a bass horn att the low end. Mark100 has thoughs about cone midrange superior to compression driver (I believe A for Ara use coaxial drivers, might be wrong though)
What is left to write:
True full range MEH as large as your doors will allow. The directivity of a 7' horn will make the (mid) bass sound and feel like a true punch yet still coherent. All drivers sealed for perfect impulse response. 12-18" woofers, they are fireing through a hole anyway, so better use smaller but more when needed to keep piston movement.
Danley has quite a few Synergies for pro sound, but in domestic environment, a single compression driver is enough. Better to focus on quality than massive SPL.
Thoughs?
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Hi Guy, now you are talking in the right direction, and I understand your objective and you give good reason for what you are trying to do and not guess because you want to do this once only and not continually want to tweak and change.
What you specify is completely agreeable and sensible. If you did this first time round, I think that you would have received more constructive information and not silly comments. I especially apologise for my comments, and will have a good think about everything you said.
The first one, I can confirm, is that you will probably not have standing waves since the wavelength is shorter than any two boundaries of the room. (Blowing over a bottle) the furthest boundary is floor to ceiling opposite corners.
Your choice of driver size diameter is a little more difficult because it really depends on the volume of air that you want to move and how the cone will respond physically. This is probably the most difficult to predict or measure. You would have to specifically look at the cone ripple since this could become a major issue. It has to be as stiff and move as piston like as possible, and the bad one it has to be as light as can be. Two issues here that comes to mind. A light piston (inductor) and a stiffness as in compliance (capacitance) to determine Fs. Now you have to consider the extra mass of the air to the size you chose as well as the stiffness of air in the cabinet, this then changes the overall Fs of the system.
Sealed or reflex sounds completely different, sealed will give a punch reflex will sound like a wet fart but cabinet volume may be sized down for the same Fs. Hope this makes sense. I have one problem with the drivers sort of facing each other, that is a very obvious comb that you are creating, unless you split each bandwidth into smaller parts that will make the crossover expensive, interference will be a given. Try doing a horizontal sweep of a similar arrangement, even made from cardboard. Even with scaled down speakers. I realize that you may expect it the same as toe-in. No, it is not. Reflex or ported will give two impedance peaks, one for the driver and one for the port at resonance, also the SPL will be very different over the same band, you can tune the port to provide you a sharper knee at Fs, but the load is more complex. You may consider each in a band pass box, but that is a lot of work and material.
Then you have not mentioned if you may be interested in transmission loading, it works like a ported design, but sounds again very different. Again more material but better response and SPL is very different from the previous two, the is also a horn drive to consider, look at the Klipsh corner horn that specifically uses the horn mouth as room boundaries. It sounds absolutely great and can go very low and deep even with reduced driver size. Efficiency goes up and cone excursion Xmax will reduce for the same SPL.
I am not a speaker guy, but have been messing with cabinet design and solving problems mathematically. Horn drives are pretty complex and an art to fold into a limited space, the example I give is probably the most complex I have ever seen and makes use of the whole cabinet in a remarkable way. I would never dream to fold it so cleverly.
My last design was an ISOBARIC transmission line, attach a photo just for interest, It went very low and was Fs moved lower than that of the drivers since the mass is acoustically coupled.
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In my just deconstructed system, I had 2x15"/ch and each 15 was driven by 1ch of a P7000S. MF and HF were driven my ME amplifiers.
What's the degree of the sloped woofer baffle? I wanna slope a 12P80Ndv2 with a CP755ND in the manner that angled baffle meets the 150h
Set it up like your car. 2 8inch or 10inch in tuned bandpass boxes. Then build a 2 way with a 5.25 or 6.5 inch woofer and a great dome tweeter. Crossover at 3.5 to 5 khz.
Electronic 3rd order at 80 for both, a pot for adjustment will smooth bass response between the mids and woofers.
You can bi amp the mid and tweeter for more precise control.
Just like your car you will need 4 or 6 channels for stereo.
Some cars use 10 stereo amplifiers.
Electronic 3rd order at 80 for both, a pot for adjustment will smooth bass response between the mids and woofers.
You can bi amp the mid and tweeter for more precise control.
Just like your car you will need 4 or 6 channels for stereo.
Some cars use 10 stereo amplifiers.