I was looking back through this thread. We finally got the Artisan Digital Sound engine installed and working on Oct.5th, 2015.
I have been tweaking and adjusting things since them. Mark Anderson has made a couple of trips to install the tuning electronics for the digital voices.
I've been using the Artisan notelevel adjustment feature to get all the ranks we're using sounding more or less level across their respective ranges. This allows me to iron out a few humps in the bass line.
I just ordered an older Allen Organ B-40 bass speaker. I intend to replace our Crown XLS1500 with a another amp. I'll use the XLS1500 to power the new Allen bass speaker. I'm going to use another more powerful amp for the two homemade bass speakers. The XLS series has a cutoff for frequencies below 20 Hz. The amp I'm getting doesn't have that limitation.
I hope to make a recording and post it here after getting the new equipment installed.
Thanks again to those in this forum who helped me so much in this project. The people in my church seem very pleased with the results. I am too. 😀
Bach On
I
I have been tweaking and adjusting things since them. Mark Anderson has made a couple of trips to install the tuning electronics for the digital voices.
I've been using the Artisan notelevel adjustment feature to get all the ranks we're using sounding more or less level across their respective ranges. This allows me to iron out a few humps in the bass line.
I just ordered an older Allen Organ B-40 bass speaker. I intend to replace our Crown XLS1500 with a another amp. I'll use the XLS1500 to power the new Allen bass speaker. I'm going to use another more powerful amp for the two homemade bass speakers. The XLS series has a cutoff for frequencies below 20 Hz. The amp I'm getting doesn't have that limitation.
I hope to make a recording and post it here after getting the new equipment installed.
Thanks again to those in this forum who helped me so much in this project. The people in my church seem very pleased with the results. I am too. 😀
Bach On
I
Only an REW plot will reveal much! Sound bites often communicate very little when we play them back except to make your hall sound full of echoes and hash and wonder where the bass went.
When an amp says it has a cut-off at 20 Hz, it means it keeps super low freq out of play (a very good thing for all systems) but almost certainly has an imperceptible effect anywhere north of 15 Hz. Good feature, not a deficiency.
Buy brand-name organ gear likely will get you inferior goods for high prices. But like the old saying about buying IBM computers, your organ committee won't complain.
Ben
When an amp says it has a cut-off at 20 Hz, it means it keeps super low freq out of play (a very good thing for all systems) but almost certainly has an imperceptible effect anywhere north of 15 Hz. Good feature, not a deficiency.
Buy brand-name organ gear likely will get you inferior goods for high prices. But like the old saying about buying IBM computers, your organ committee won't complain.
Ben
Earlier in this thread I was using a CD player to play test tones and organ music. We discovered that the CD player was only putting out a 0.7 volt signal, instead of the 1.4 the amp was designed to accept.
I don't know the signal strength of the Artisan Sound engine.
IF I connect a volt meter to the output of the sound engine, would it show me the voltage. I' m guessing I'd have to set the meter for AC, rather than DC.
It has occurred to me that the input signal of the Artisan system may be lower - like was the case of the CD player.
That means the Crown XLS1500 is producing watts more like an XLS750. For the 4 ohm circuits it should be putting out 525 watts per channel. I'm wondering if it may only be putting out half that power.
Bach On
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I don't know the signal strength of the Artisan Sound engine.
IF I connect a volt meter to the output of the sound engine, would it show me the voltage. I' m guessing I'd have to set the meter for AC, rather than DC.
It has occurred to me that the input signal of the Artisan system may be lower - like was the case of the CD player.
That means the Crown XLS1500 is producing watts more like an XLS750. For the 4 ohm circuits it should be putting out 525 watts per channel. I'm wondering if it may only be putting out half that power.
Bach On
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The "windowed" sweep signal supplied by the honorware software REW is a different creature than playing discrete tones, and the right way to measure. In a room, might be large differences at your mic between a 22 Hz tone and a 24 Hz tone. So, use REW to sweep and average (say, "1/12 octave").
But having said that, a credible test recording (like the Denon test CD) is likely to provide a honky-dory signal to the downstream units (unless the connect is very wrong). Loud or soft, doesn't make that much difference to performance quality until you are scraping the limits.
Ben
But having said that, a credible test recording (like the Denon test CD) is likely to provide a honky-dory signal to the downstream units (unless the connect is very wrong). Loud or soft, doesn't make that much difference to performance quality until you are scraping the limits.
Ben
Best thing to do is make a CD with a 60 hertz tone. Set your volt meter to AC and take your measurement.
I can send you either a test tone of 60 hertz as a file or a link to a program that will generate it for you.
I'm pretty sure you can burn a CD.
Mark,
I have the test tone. So I measure the signal. What should I see and how is it to be interpreted?
Bach On
I have the test tone. So I measure the signal. What should I see and how is it to be interpreted?
Bach On
Well depending on the signal you should see a voltage. If I remember correctly maximum signal out of a CD player is usually 1.5 volts.
I can't remember the full power signal voltage for your amplifier.
If you play an 8 foot C flue pipe that will be pretty close on the Artisan as well.
You want to compare the signal voltage to the amplifier. Outer ring is ground on an RCA cable. Inner pin is hot.
I can't remember the full power signal voltage for your amplifier.
If you play an 8 foot C flue pipe that will be pretty close on the Artisan as well.
You want to compare the signal voltage to the amplifier. Outer ring is ground on an RCA cable. Inner pin is hot.
Could somebody please repeat what the problem is.
(There are two separate issues: gain management and max power, delivered to your speaker. Neither is always firmly established by reading the spec sheet. Gain management is easily addressed. But max power - an important limit to you, I'd guess - can't be measured easily or safely.
But if you're a gamblin' man, you can try to confirm, "Got loud enough for me and didn't self-destruct in 30 seconds". Of course, you could be expensively wrong.
Techie note: I'd play the speaker loud and see how close the amp's output voltage is to the rails and do a quick calculation for amperage. That will provide some guess at the headroom. Pretty loose. The folks who do rock concerts would know better.)
Ben
(There are two separate issues: gain management and max power, delivered to your speaker. Neither is always firmly established by reading the spec sheet. Gain management is easily addressed. But max power - an important limit to you, I'd guess - can't be measured easily or safely.
But if you're a gamblin' man, you can try to confirm, "Got loud enough for me and didn't self-destruct in 30 seconds". Of course, you could be expensively wrong.
Techie note: I'd play the speaker loud and see how close the amp's output voltage is to the rails and do a quick calculation for amperage. That will provide some guess at the headroom. Pretty loose. The folks who do rock concerts would know better.)
Ben
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I contacted the Artisan Sound Engine rep last night. He's checking with the design team to find out what the output voltage is supposed to be. But he mentioned in his e-mail that they have sometimes had to use an inline pre-amp in some installations - particularly for pedals.
Could somebody please repeat what the problem is?.
I'm guessing that the consensus may be that this is much ado about nothing. I've said the sound in our pedals is adequate. But I don't think the sound quality is quite as clean in the pedals as it is in the manuals. The manuals are all using the same Allen HC12 speakers - six of them. And there are six Point of Presence speakers playing along with them. These speakers were designed to play organ sounds well. And they are doing so for us.
The bass line - the pedals in this case are being played through two amps and three speakers. Two of the speakers are homemade ported boxes. They get most of the sounds that are from 96 Hz.. down to the lowest tones, which is 16 Hz.,
Pedal sounds above 96 Hz. are being routed to an Allen HR100 speaker. It has a 10 inch woofer and a horn. It has a typical frequency response of 40 to 20,000 Hz. This speaker gets the partials and overtones from the pedals through a separate Crown XLS1000. It is a very efficient speaker that requires less power. The Crown amp is set for HIGHPASS mode for sounds above 96 Hz.
So the homemade part of this mix may be suspect since it is where I'm detecting issues - slight, but IMHO, there.
If our Crown XLS1500 was putting out full power, it should be able to provide 525 watts to each of the homemade boxes. I'm currently having to run both the XLS1500 channels wide open.
If the input to this amp is lower than the amp's design calls for, then the amp may only be producing something on the order of 262 watts per channel.
My limited understanding is that under-powering a speaker CAN be detrimental. Many plate amps on sub-woofers typically are rated for 700 watts or more of power. 262 watts is quite low for speakers being asked to play 16 to 96 Hz. signals at volume.
One of the homemade boxes contains two 8 ohm 15 inch Dayton drivers rated at 300 watts RMS and 600 max. They were wired together to produce a 4 ohm load. So the amp (as rated) should be a reasonably good match for this speaker.
The other box contains the Stereo Integrity HT18 driver which is rated at 600 watts RMS. The driver has two 2 ohm voice coils. It was wired so the resulting circuit is 4 ohms.
The first box has an internal volume of roughly 12 cu. fit. It has a port.
The second box is closer to 10 cu. fit in volume. It also has a port.
These speakers were tested and measured and seem to be able to produce the sounds being asked of them.
The Crown XLS1500 is sending the same signal to each of the stereo channels. I can, therefore, use the amp's volume knobs to control each speaker volume independently.
Bach On
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Distorted sound: listen to each rank separately or listen to the feed to each rank on good headphones in another room (esp. if you can keep the speakers connected to load their amp normally, after passing through a headphone amp or otherwise buffering the power amp that feeds the speakers.
"Suspect" about what?
"Underpowering" has no detrimental effect until you are trying to get more clean sound out of an amp than it can give, assuming you have enough voltage going into the input to drive it loud. See my previous post on assessing if the amp is straining. Play 45 Hz (for a bunch of reasons) loud and see what the voltage to the speaker is. Report back with the speaker impedance and the voltage you measure.
Ben
"Suspect" about what?
"Underpowering" has no detrimental effect until you are trying to get more clean sound out of an amp than it can give, assuming you have enough voltage going into the input to drive it loud. See my previous post on assessing if the amp is straining. Play 45 Hz (for a bunch of reasons) loud and see what the voltage to the speaker is. Report back with the speaker impedance and the voltage you measure.
Ben
Bach On,
A quick look at the XLS meters would tell you if you are reaching the -10dB indicator, which would only be 52 watts at 4 ohms. Checking the output voltage with a true RMS meter on the AC scale will show you how close to full output is being reached, 45.8 volts is 525 watts at four ohms. 32.4 would be about half power, 3 dB less. You would only read 45.8 if the crest factor of the tone generators was 3 dB like a pure sine wave, the crest factor is likely to be upwards of 6 dB, in which case the most RMS voltage the amp would produce at clipping would be 32.4 volts RMS.
Each additional note played adds about 3 dB, if you play a chord you should see a lot more voltage than a single note.
"Under-powering" being detrimental is a myth. The origins of the myth are this: an amp driven into hard clipping can produce more average power than it's rating would indicate. Ordinary music would seldom be less than a crest factor of 12dB, so the average RMS power from a 500 watt amp at peak would only be 62.5 watts. Run the amp into hard clip and the average power could be close to 500 watts, while an un-clipped 1000 watt amp would only deliver 125 watts RMS.
Assuming your speaker power ratings are correct, they should be able to take as much power as your amp can deliver without clipping. If you don't see ever see the clip/limit indicator light when you hit as many notes at once as you are likely to play, you could use a pre-amp or an amp with more gain. That said, if the low end is balanced and you are happy with the output level, no reason to change anything.
Art
Thanks for the details, Weltersys. I do have an older RMS meter. I'll try it on the system.
Many of the contributors over at the Organ Forum are my sources for "Under-powering being detrimental" statement. A great many there have told me this.
Bach On
Many of the contributors over at the Organ Forum are my sources for "Under-powering being detrimental" statement. A great many there have told me this.
Bach On
Yes, it is definitely detrimental in a number of ways whenever you exceed its limits. But not detrimental otherwise.
Good chance you are already quite beefy in power, maybe.
I can't speak for synthetic organ tones, but some musical sounds have monumentally loud instantaneous peaks. It's statistical thingy. A women's choir (such as singing good old Brahms' lullaby) makes a terrific test sound for that reason (providing of course, that the recording hasn't trimmed-off the peaks like on some those very cooked pop music recordings wisely or erroneously advocated on a recent thread).
In terms of challenging your amp's limits, the pretty meters on the face may not tell too much of the story. I'd like to hear what they are measuring (in reality, just the output volts???) before trusting them. Better to have a handle on Ohm's Law and know two or three out of three parameters of the output (volts, ohms, or amperes).*
Ben
*The meter I'd trust would be revealing instantaneous temperature of the heat sink, if that were possible.
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Ben,
The Crown XLS series has thermal compression indicators, as well as -20 dB below clip, -10 below clip, and clip (or clip/limit when limiter is engaged).
The XLS 1500 clips at 300 watts at 8 ohms, 525 watts at 4 ohms (which is the nominal load of the OP's speakers), and 775 at 2 ohms.
Crown's meters can be trusted to do what they are intended to do, give an operator an idea of what (if any) headroom is available.
Temperature of the heat sink would have no relation to available headroom, the thermal compression indicators are helpful to show if the heat sinks are blocked or too dirty, or the amp is being pushed beyond it's design duty cycle.
Art
Attachments
Bach On,
The myth will continue until the truth is explained to the contributors, and they come to understand that average, not peak power is what burns up woofer coils. You can't "under-power" a speaker, but you can make a small amp overpower a speaker by clipping it hard, easy to do with sustained pedal notes.
One problem arises with the AES2-1984 power rating, which is conducted in free air and based on the minimum impedance. A free air speaker's average impedance will be much higher than the average impedance in a cabinet, making the thermal rating higher than it typically would be in real world use, unless using an open baffle. To be safe, sustained RMS power should only be about 1/2 the AES rating.
Art
Yes of course: they measure nothing but output voltage as I suspected. Sometimes there are multiple scale markings or switches to coordinate with your nominal speaker load a bit better.
The meters can give a rough indication but you still need to know the impedance of your speakers and that changes with frequency and is wonky at the subwoofing frequencies. In short, watching the meters tells you exactly what the output voltage is but not how you stand vis a vis running out of moxie.
Ben
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When the clip light illuminates, you know the amp has "run out of moxie", regardless of speaker impedance. When the -10 dB lights, you know you have about double the moxie available at 1000 Hz, or four times the moxie at 20 Hz, assuming "moxie" equates to loudness...
.... and just what is the clipping light connected to? Do you know? Are we just talking voltage relative to rails again but with an idiot light for those who can't read a meter in the rack?
B.
@ Bach On
What a coincidence, i was wondering how this was progressing, only the other day ! Good to see you "back on" 😉
Did you make the changes to the capacitors etc in the mixer/pre i & others suggested ? If not, why not ?
Re - True AC RMS meter readings. For those that don't already know, any multimeter without a TRMS feature, Will read TRMS if fed a FIXED frequency, eg 20Hz etc. The only limitation is usually @ higher f's above a few hundred Hz, because they are not as accurate then.
What a coincidence, i was wondering how this was progressing, only the other day ! Good to see you "back on" 😉
Did you make the changes to the capacitors etc in the mixer/pre i & others suggested ? If not, why not ?
Re - True AC RMS meter readings. For those that don't already know, any multimeter without a TRMS feature, Will read TRMS if fed a FIXED frequency, eg 20Hz etc. The only limitation is usually @ higher f's above a few hundred Hz, because they are not as accurate then.
Zero D - I did the capacitor change on the Rolls unit. I must have screwed it up. It would not work when I reassembled it.
I ordered the ART version today. It has a frequency response that extends down to 10 Hz. So no capacitor change would be required.
Bach On
I ordered the ART version today. It has a frequency response that extends down to 10 Hz. So no capacitor change would be required.
Bach On
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