Without spelling it out you are making a valid point.
That is the difference between a high quality driver like that Faital and a dirt cheap no name thing that doesn't really meet it's advertised specs.
So the idea of using the compressor was to keep the signal level below that which is blowing the speakers, no matter what. So when she shrieks into the mic, the same level comes out as when she speaks. Only the voice timbre changes.
Of course if you crank the post-compressor gain up so no matter what input level is coming off the mic, the speaker is getting a level that will blow it, it will die. Dont do that. "This is as loud as it gets, Honey. You cant make it go any louder by screaming harder".
Of course if you crank the post-compressor gain up so no matter what input level is coming off the mic, the speaker is getting a level that will blow it, it will die. Dont do that. "This is as loud as it gets, Honey. You cant make it go any louder by screaming harder".
One would rather hope that a 250w-rated speaker would actually take 250w - it's one of the easiest specs to measure.
Moving back towards the original topic, for vocals-only reinforcement, I'd look for a good pair of 10-12" powered mains. Yamaha DBR12 is the absolute minimum. A DXR10 would be an improvement, and smaller as well.
I dismantled and tested a DBR10 (which won't do this job IMO), and found there's a LOT of limiting in there, which makes them pretty much indestructable from a driving-it-too-hard point-of-view.
Chris
sorta agree with most of the comments here but will mention 4 points.
- Poor amps often oscillate when overloaded on real speaker loads. This happens at supersonic frequencies which you can't hear but are just right to fry your treble units. BTW, wanna guess how often your amp overloads?
- No one has mentioned feedback which you CAN hear and will usually fry your trebles too
- In my experience, piezo horn drivers are more robust than moving coils. Wish there were good piezos
- Lastly, most PA speakers now have a PTC fuse on the treble units. But they are almost always in the wrong place. They should be on the INPUT to the treble xover, NOT on the OUTPUT feeding the treble unit. The sure sign of this is when the treble unit dies, it takes out the treble xover too. When I buy a new PA speaker, I always have a look inside & relocate the PTC fuse.
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Piezo elements are only “robust” when you apply proper filtering to them. The minimalist crossovers used in cheap PA speakers that use them are usually inadequate. When using proper filtering, a piezo is more robust than a 1”-coil compression driver. ANY 1” coil driver. The jury is still out compared to a 2” coil. A *good* 2” coil driver (expensive) will beat most piezos, simply because the high sensitivity allows you to pad the driver more. A poor one might *require* too much power to get the required level and the piezo wins. A 3” coil beats the power handling out of any piezo. Unfortunately, those are pricey. Not to mention weighs more than the woofer unless you spring for neo magnet$. Cheapest one that was ever any good went for $169 at its lowest and those are NLA on the DIY market. JBL may still be using them. I bought some of the last of them PE had, and a stock of diaphragms.
Surely you have seen the specs fudging that goes on with speakers, they all do it but it's most aggregious at the lowend of the market where they often just make up something.
That isn't my experience, I have a shelf full of blown piezos that couldn't survive where a conventional bullet driver had no problem. In fact it took 3 piezos to somewhat equal the output of a single bullet and even then the bullet sounded much better.
I’d like to see *that* driver - I’ve never seen a 1” coil driver take more than 10 watts of average power without smoke. Most of them around 6 watts. IME, a piezo will take 9 volts RMS all day. They do make ring radiator bullets with 2” and 3” coils. And they will rip you a new eardrum with the power they’ll take (perhaps as much as 40 watts average which is damn loud at 110dB/W. And people use them in competition car systems (wouldn’t want to be inside during the test).
Do not clip the amplifier, if you do, the speakers die.
When I used to work for a living, I had a pair of 200W cabinets as my test units, and they had hundreds of amplifiers up to 2500W through them. After 32 years, they still had their original drivers; but the amplifiers were never driven to clipping.
When I used to work for a living, I had a pair of 200W cabinets as my test units, and they had hundreds of amplifiers up to 2500W through them. After 32 years, they still had their original drivers; but the amplifiers were never driven to clipping.
I've seen it, and been annoyed enough to write an article on the subject: Spec Wars: Looking Inside Loudspeaker SPL Specifications - ProSoundWeb
It's more for active speakers, but I'm sure you'll see my point.
Chris
Loved your article
Peavey also got fed up with the silly "Spec Wars" game and in 2005 published:
https://peavey.com/PDFs/THE_LOUDSPEAKER_SPEC_SHEET_GAME_2005.pdf
Not that it changed Industry evil ways by any means
Peavey also got fed up with the silly "Spec Wars" game and in 2005 published:
https://peavey.com/PDFs/THE_LOUDSPEAKER_SPEC_SHEET_GAME_2005.pdf
Not that it changed Industry evil ways by any means
Where they use a “maximum possible level” sensitivity from the driver(s) AND tell you that the internal amplifier with a 63 volt unregulated switching power supply (with no load, and a 2 amp current) limit can produce 500 watts. Or even more, if they take it a step further and use the DC resistance to call it 600. They used to call THOSE “car stereo watts”.
THE problem with powered speakers is that you don’t know what is in there. You can *guess*, based on price. When you buy drivers you’ve got a pretty good idea what you’re getting. You pretty much know what a 3 inch voice coil is good for, what a 6-mm x-max motor and suspension is supposed to look like vs. a 10mm, and you can calculate half space reference sensitivity from measured T/S parameters (and you know what brands tell the truth on published T/S parameters). Actual amplifiers can be measured and benchmarked. Or even just listened to under use conditions. And there is enough information on even this forum for a newbie to pick something that is “good” to start with.
This is the reason: the amp has too big power for these loudspeakers. This amp has power 1000W/4 Ohms. The loudspeaker is 8Ohms this means that the power is 500/4Ohms. The loudspeaker is nominated as 250 W program and 1000W peak and they both are much less then what we have from amp. Note that amp can output any frequency from its band 20…20000Hz at its max power. And usually 2-way loudspeaker for common use has HF driver approx. 10 times weaker that woofer. In your example LF/HF 250W/25W or so. From the other hand let’s look at the active model of the same speaker GX15A, we see that it has program output power 170(!) W and let’s agree that internal amp was chosen to match tto the power of loudspeakers for reliable work.
Yes, of course! I just wanted to say that the amplifier does not match the loudspeaker and why it might be failing. If there is a suggestion to give advice on what speaker to choose, I can advise. However, even now you could say that you need a three-way speaker for vocals. The main thing is to make sure that its wattage is chosen correctly. There are some difficulties here, because the power of the amplifier is rated on a sinusoidal signal, and the power of the loudspeaker is rated on a noise signal.
It doesn't work that way. If the amplifier has a sine wave power of 250W/8Ohms, as in this case, it means that on the program signal it can be twice as much, i.e. 500W. I gave an example of the power of the same, only active, loudspeaker. It is equal to 170W of the program signal. So its amplifier power is 2 times less. All sources on safe loudspeaker operation say that for live performance, where randomness cannot be ruled out (e.g. acoustic feedback), you should use an amplifier with a sine wave power of half the program loudspeaker power.