- Can I use Pizeo Tweeters, or???? - 2 Updates
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| Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: May 05 05:12PM +1000 >> Any tips or suggestions? >> Thanks in advance. > Piezos are not the 'junk' some opine, **Oh yes they are. Absolute crap. Rip one apart and you'll wonder that they even work at all. far from it. But they're not > can deliver quite good performance at relatively low price. Their > shortcoming is the frequency response is a bit uneven at the top end, > but domes, cones etc aren't flat either. **They have a number of serious problems that rule them out of any high quality audio application. Sound reinforcement is probably OK, because the listeners don't give a shit. > operating range. Always put a series resistor on piezos, 10R is ok. > Otherwise the amp sees a capacitive load, and some are not ok with > that. **The resistor MUST be in parallel (when used with a crossover). The capacitance exhibited by a typical piezo driver is almost inconsequential. Any amp that runs into trouble with such a load will have exploded years ago. > get a happy result from piezos than domes. > Crossover frequency is typically 1 - 4kHz. Tweeters only handle > somewhere vaguely in the region of 20% of a speaker's input power. **Much, MUCH less than that. However, as Phil stated, they still respond to bass frequencies and thus benefit from a crossover. -- Trevor Wilson www.rageaudio.com.au |
| tabbypurr@gmail.com: May 05 09:08AM -0700 On Friday, 5 May 2017 08:12:27 UTC+1, Trevor Wilson wrote: > On 4/05/2017 9:58 PM, tabbypurr wrote: > > Piezos are not the 'junk' some opine, > **Oh yes they are. Absolute crap. that's not a sensible factual claim > Rip one apart and you'll wonder that > they even work at all. I already know how they work, and have constructed experimental speakers using piezo technology. I don't wonder that they work, the principles are well known, and have been for a long time. > > but domes, cones etc aren't flat either. > **They have a number of serious problems that rule them out of any high > quality audio application. 'high quality' is a bit too vague there. They're good enough for the average domestic hifi. > > Otherwise the amp sees a capacitive load, and some are not ok with > > that. > **The resistor MUST be in parallel (when used with a crossover). a resistor must. > capacitance exhibited by a typical piezo driver is almost > inconsequential. Any amp that runs into trouble with such a load will > have exploded years ago. Maybe you should tell that to the amp I had that couldn't drive them stably without a resistor. It's clearly not factual. > > Crossover frequency is typically 1 - 4kHz. Tweeters only handle > > somewhere vaguely in the region of 20% of a speaker's input power. > **Much, MUCH less than that. Percentage does vary according to the music. > However, as Phil stated, they still respond > to bass frequencies and thus benefit from a crossover. NT |
| bruce2bowser@gmail.com: May 05 04:55AM -0700 > Western Digital lockup. Don't believe me, look up on Google WD1600BEVT > password and you will learn very quickly. It is a known fault > and that is why I do not want to fuck with the BIOS or anything. I'm certainly not an expert at plant extracts, but I imagine that yes, some are stronger than others. But I thought that most any type would drive bugs away. |
| Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: May 05 05:06PM +1000 > positioned sideways (I had to use a graphic editor to fix that), and > it's very difficult to fit the pieces together. Plus there are sections > missing. **There you go. You're on your way. > (The identical chip and circuitry on the working channel is barely > warm). > So, I am pretty sure at this point that this 5532A chip is bad. **Oh yeah. The 5532 was, in it's day, a very high performance audio OP amp. Nowadays, they're a dime a dozen. Still a decent OP a though. Well, dual OP amp. For test purposes, you could try almost anything. Such as: TL072, LF353, LM1458, LM833 (the closest equivalent to the 5532). Best to stick to the 5532 though, as it can source more current than most OP amps. One point: When you whack a new one in, check for DC offset and oscillation. A remote possibility, but a real one. > 5. Common > I guess before I can do much more, I have to find a place to order a > 5532A chip (or several of them so I have spares). **They should be very easy to locate. I keep a dozen or so in stock. > in electrical tape, and clipped the other end to my probe. > WHAT THE HECK DO YOU GUYS USE FOR PROBES ON THOSE TINY PINS? DO THEY > SELL SPECIAL PROBES OR PROBE TIPS FOR THIS PURPOSE? **Yep. They sure do. > The good thing is that all the ICs in this device are plug in socket > types. Thank God for that!!! **Your job is then dead easy. -- Trevor Wilson www.rageaudio.com.au |
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