MickyMcD

The compression and rarefaction generated by the port can be of reverse polarity and interfere with the original signal from the driver. Of course, why didn't we think of that before? Thank god we have SPL2K with us. Thanks man. Cheers, Mick

Actually, I agree with Charger. Not for the phase issue with proximity to the port, that should be well within acceptable limits. However, loading in the blue region may be detrimental to your desired sound. It may be far too 'boomy' resonating in that open box. tl;dr, Load green. CHeers, Mick

Correct Steve, DC is the worst thing you can feed a driver. One reason for that is simple physics. Speakers work through electromagnetic fields, generated by passing current through the coil (solenoid). When you pass DC current across the solenoid, you will create a magnetic field of so many Webers in one direction, that will move the cone assembly in one direction and hold. This movement is often quite violent and will overheat the loudspeaker quite quickly. Secondly, and mainly, DC generated through power amplifier stage output is FATAL to drivers. Pure DC unmodulated current from a power amplifier of ANY class is generated in two ways. Firstly, you can fault the amplifier, often by dropping a FET or shorting a rail. Secondly, you can clip the waveform and provide DC output. When this DC is created, it is done so at the most extreme level of the voltage rails, thus providing very high voltage and amperage DC output that will roast your solenoid like a christmas dinner. Simple solution; Use amplifiers that are correctly rated, and will put out an output power that your speakers can handle. It never hurts to have a wee bit of headroom so you can safely handle transients without inducing harmonic distortion, but not too much. Just know your system back to front, front to back. Know what it can handle, what it can't and what it does/sounds like/smells like when faulting. Cheers, Mick

In your design, go blue. It will pervent back pressure from resisting the cone movement and will also have the benifit of cooler fresh air being brought to the motor structure. Cheers, Mick

Like many sound tech's, I started out as DJ. Good ol' Virtual DJ V1.1 That thing used to be so much fun. Still got my old rig, upgraded it and still use it for little gigs that work don't want or me mates just want me to mix. Love that rig Beefy, that shit is clean. Man, I wish our rig's were that polished back when I worked for a DJ company. And from personal experience, add two passive 18" woofers underneath your main FOH and Bi-Tri amp. You will be amazed. Cheers, Mick

I am not too sure if that was sarcastic, but I think it wasn't. Thank-you. I have spent many years now learning and being taught by sound technicians across Australia. Unfortunately, as it goes with all work, if I didn't know my stuff I'd quickly find my ass out on the sidewalk and looking for another job. Cha-ching, he's in the money. Pre-amplifier stage distortion will not harm your loudspeakers. Also, thank-you Megalo for going that one step further and conducting experiments and displaying the evidence to the forum. No-one can argue with the proof you delivered. Cheers, Mick

Overdriving a Class A/B, A, B, D, or H power amplifier also results in an increase in output power and induces DC current across the coil (class TD, as used by Lab.Gruppen, and valve amplfiiers behave differently). DC Current is a speaker serial killer, and should be avoided. Overdriven amplifiers are very easy to hear if they are powering hi, hi/mid, mid or low/mid loudspeakers. However, overdriving low end amplifiers' results in almost inaudiable distortion unless it is harshly overdriven. Clipping a waveform induces Harmonic Distortion. Overdriving a 10k sine wave will result in the next harmonic overdriving at 20k, which is extremely hard to hear with human hearing. However, overdriven waveforms at a lower frequencies induce harmonics that are quite audible. A good document writen by Peavey outlines the basics of clipping, however it focus' mainly on pre-amplifier stage distortion. Never the less, this document is extremely healpful and informative. http://www.peavey.com/support/technotes/co...ngrevisited.cfm Cheers, Mick

Congrats man, that's great news. I look forward to seeing your build man. But you'd better thank your wife and show her some appreciation. Giving you her tax return so you can get a car and beats and she goes without...that's dedication man. Treat her to a nice weekend away or something man. Cheers, Mick

Fair call. Off Topic is Off Topic. Speaking of Orion though, I have heard from a source that tells me the Orion woofers (HCCA? I think that is correct) can only be mounted vertically because of motor weight. Is that true? Cheers, Mick

Okay, and the point of the thread is.......? Cheers, Mick

I'm chuckling, this must be one mighty fine joke. Right, a damping factor of 10k and a S/N of 150db. I wonder how many people believed this? Though, do correct me if I'm wrong. If this is real, I'm sure that Peavey, Crown, AT, QSC, Lab Gruppen and Quest would love to know how to get damping and S/N that high, let alone how to run that low a rating to a conventional amplifier. Cheers, Mick

As a general rule of thumb we use in the entertaiment industry is the low pass filter to woofers should be around 100-120hz. That means from 100-120hz and below is sent to the sub feed or aux feeds. Try raising the LPF to 115hz and see how that goes. Cheers, Mick

Believe it or not, we have heard of sarcasm. This is an internet forum. We don't hear anything, we read. I'm not sure, maybe we thought you just might be that stupid. Splx woofers do not perform well at all in sealed boxes, especially boxes that small. I have no input on the T-5, I have never used one. Cheers, Mick

Had my drink spiked, reacted with medication. Couldn't walk, talk, had fevers etc. My girlfriend, whom I love more than anything else in the world, and I cannot see each other as often as we could as her mother and I have had a falling out. Correction, she has a problem with me, and 'requested I leave' the house. I have chronic insommnia, I haven't slept in months. I feel sicker than I have in years. My mental illnesses are returning. I'm scared of him. The shells in my closet look pretty appealing right now. Then again, I'm so tired/fucked up I'll regret posting this tomorrow. Meh. Cheers, Mick

Not to thread jack, but why is there a general misconception that Sound Reinforcement drivers are 'harsh'? PA drivers are engineered to be acoustically flat, that is with a flat frequency response curve. If they are good enough to be used in line arrays and concert SR applications, who's to say that they cannot function in a car audio environment? Or do car audio enthusiasts find them far to responsive to high transients/harsh? This is a genuine question, I have often pondered this. Cheers, Mick

Ah, I misread your post. I see we are on the same side. My mistake, I apologise. Still, for the original poster, is 1.34 ohms the reading at the coil or at the terminal? Is this IMpedance or DC resistance? Cheers, Mick

Of course Audiofanaticz, more power is good power. We all love power. We never love amps going bang. From a purely safety point of view, I disagree with running power amplifiers below their rated minimum impedance. However, you are correct with box rise, cable rises etc. Is this load at the coil, or at the terminals? Also, is this DC resistance or impedance? Cheers, Mick

I have glandular fever. Work has cut my sick leave from a week to two days. The better half is still in sydney. Work is behind schedule Work hasn't paid me Reputation is being damaged because useless fucking cunts won't return gear to Civic Theatre. Civic Theatre has me on 18 hour shifts, back to back for a week then 9 hour shifts every night after 7 hours of school. Pyrotechnician is a prick, can't work with him. Can't afford to repair PA system Can't afford to buy my lover the things she deserves Can barely see from migraines Splattered my arm with burning solder, so now have nice little 2nd degree burns down my arm. Fuck this shit, fuck that, and above all, fuck you. Cheers, Mick

Let's put it really simple. If your amplifier is rated SAFELY at a minimum of 2 ohms, then you don't go below that. 1.34 ohm is below 2 ohm. Don't go that low on a 2 ohm amp. Done And Done Cheers, Mick

You want someone to kill? Come to Australia where the men that gang raped a ten year old girl got off scot free. Where that same girl was raped when she was six, taken from the community, then put back UNDER THE SAME FOSTER CARE AND GANG RAPED AGAIN. The judge said that 'she was probably asking for it. It was very possibly childish experimentation' Or where a father in Brisbane raped and murdered HIS OWN FUCKING DAUGHTER. Fuck Hitler looking like a saint, I'll make Lucifer piss his pants in fear of what I would do to these dispicable pieces of shit. Cheers, Mick

That is correct sir. I use 18" woofers, and nothing smaller. Seeing as I use the woofers in a pro audio situation, I do not want the lower piston area per watt associated with 15" bass drivers. I also prefer the handling, performance and sound of a larger cone transducer over a smaller cone transducer. Cheers, Mick

Because with a larger, therefore heavier, woofer, the diaphragm may continue to move after the cycle has ben completed. It may only move a fraction of a centimetre, but that fraction every cycle is enough to add unwanted colour to the sound. Some guitar speakers and instrument amplification use heavier diaphragm drivers to deliberately color the sound. It also has to do with your amplifier's damping factor, but that is irrelevant to this topic. Cheers, Mick

Funnily enough, it is 1.34 Ohm. Amplifiers do not need to be run at exactly 1,2,4,8,16 ohm etc. In fact, they almost never are. Ever looked at your speaker's impedance curve? Definately not only one value of resistance. Factor in impedance rise and wire resistance as duct_tape mentioned at it would be a wee bit higher. Cheers, Mick

'Tis my sister's 21st b'day tonight. Plan on getting piss drunk with my boss, who is Kat's friend. Shall be interesting when we come back to work. Cheers, Mick

I know you don't mean it to be, but that is really suss.... Cheers, Mick