Hi 4pyros,
Post #73: "... would be afraid the cone would hit the redcer baffle in you drawing. I am thinking maybe I could easy do a slot baffle on the inside of the existing mounting baffle?..."
The drawing in Post #72 is just an example, you will have to flesh in the final dimensions of the spacer rings, thickness as well as their shape. I don't have the drivers available, and Eminence does not publish drawings of sufficient accuracy. You will have the same problem with a slot as with a round hole (see djk's picture in the Single Sheet TH challenge, Post #1059:
http://www.diyaudio.com/forums/subwoofers/170771-single-sheet-th-challenge-106.html ).
Regards,
Post #73: "... would be afraid the cone would hit the redcer baffle in you drawing. I am thinking maybe I could easy do a slot baffle on the inside of the existing mounting baffle?..."
The drawing in Post #72 is just an example, you will have to flesh in the final dimensions of the spacer rings, thickness as well as their shape. I don't have the drivers available, and Eminence does not publish drawings of sufficient accuracy. You will have the same problem with a slot as with a round hole (see djk's picture in the Single Sheet TH challenge, Post #1059:
http://www.diyaudio.com/forums/subwoofers/170771-single-sheet-th-challenge-106.html ).
Regards,
Sorry I did not get to update sooner;
Busy getting ready for the bosses wedding.
The system workrd well but I had the power to the subs turned down. I had vary little time to break the subs in and thay are stiffer than @#*& after getting treated so I did not give them full power.
Even with the subs turned down the highs were still to high so I started adjusting the EQ with a nice slope ending at 20khz down by -15db.
The show was at 10PM and by 11PM the fog was so bad I could not see 20 feet in fount of me. I had the speakers repacked before the fog was to bad.
Without any changes to the 4pyros box and just the limiter and higher low cut off thay sounded good and had no signs of damage.
I am running 1/2 the system this weekend weather permiting, Irene is coming!
Then the hole system will be at Mount Airy Casino, next weekend,Laber day.
I will be able to turn it up some more thare and I will let you all know how it goes.
I have been looking into getting a speaker power meter for a better indication of when the subs hit 500 watts. Maybe somthing I can make. Not much good info on the web. Any Ideas????
Andy
Busy getting ready for the bosses wedding.
The system workrd well but I had the power to the subs turned down. I had vary little time to break the subs in and thay are stiffer than @#*& after getting treated so I did not give them full power.
Even with the subs turned down the highs were still to high so I started adjusting the EQ with a nice slope ending at 20khz down by -15db.
The show was at 10PM and by 11PM the fog was so bad I could not see 20 feet in fount of me. I had the speakers repacked before the fog was to bad.
Without any changes to the 4pyros box and just the limiter and higher low cut off thay sounded good and had no signs of damage.
I am running 1/2 the system this weekend weather permiting, Irene is coming!
Then the hole system will be at Mount Airy Casino, next weekend,Laber day.
I will be able to turn it up some more thare and I will let you all know how it goes.
I have been looking into getting a speaker power meter for a better indication of when the subs hit 500 watts. Maybe somthing I can make. Not much good info on the web. Any Ideas????
Andy
Well the show must go on! Especially when it's the bosses daughters wedding!
Setup was not that bad the rain held off till after 6PM
I had the speaker stacks set up under pop up canapys and covered with tarps.
We shoot at 8:30 in heavey rain.
I started with the tarps still on but at the higher volume levels thay sounded bad
so I had the tarps off of the last 10 mins of the show.
Break down was in pouring rain. No fun!!!
Cheaking for damage today.
Andy
Excursion can mess up your cones, as you found out.
You already have "power meters", both in your console and in your DSP limiters, if you just bother to set them up properly.
Once you set your systems gain structure up properly, you won't be making wild changes, remember 10 dB requires ten times the power, if you are making 15 dB cuts on your EQ your gain structure is not even in the ballpark.
Look at your V.U. meters on your mixer, see how they relate to the speaker excursion, same for the DSP.
Run your board level below the level that exceeds Xmax.
Forget about watts.
Velleman Mono LED Power Meter Kit
agree, set it up, limit it, and forget it. -- fool proof.
However the above would be a good 'visual' that you can build into something. Change the below 400watts to green leds, and then leave 400 on up red. If you see red blinking constantly, you know you are really into it.... you see 700 light and you are in cone damage territory.
agree, set it up, limit it, and forget it. -- fool proof.
However the above would be a good 'visual' that you can build into something. Change the below 400watts to green leds, and then leave 400 on up red. If you see red blinking constantly, you know you are really into it.... you see 700 light and you are in cone damage territory.
Thanks guys.
One problum I have been having is we use different setups all the time.
Sometimes I may have two stacks per channel, IE 4 ohms and sometimes only one stack per channel, IE 8 ohms. Seeing that the max power changes with speaker impedance may be it shouldn't matter.
Another problum is the limited number of leds only three one the amps and 5 on the DSP.
The last problum is the lack of a sutible place to crank it up. I am almost thinking of making dummy loads to make all the settings.
Maybe I can work out all the math to determine the fianl settings, but that maybe beyond me.
I need to come up with a plan to get this settled for good!
Andy
One problum I have been having is we use different setups all the time.
Sometimes I may have two stacks per channel, IE 4 ohms and sometimes only one stack per channel, IE 8 ohms. Seeing that the max power changes with speaker impedance may be it shouldn't matter.
Another problum is the limited number of leds only three one the amps and 5 on the DSP.
The last problum is the lack of a sutible place to crank it up. I am almost thinking of making dummy loads to make all the settings.
Maybe I can work out all the math to determine the fianl settings, but that maybe beyond me.
I need to come up with a plan to get this settled for good!
Andy
take art's suggestion -- forget watts, look for volts. The velmann that I pointed you to is just a volt meter. It's calibrated to 2000watts at 8ohm, with a 400 and 700 watt led. Regardless of your true ohm load, 1,2,4 subs, the voltage per sub is the same as long as you are running subs in parallel. In effect it'll tell you 'watts per sub.'
Jim, the Velleman wattmeters kits are all impedance related and readings are based on linear impedances of 4 or 8 ohm. You have to change the measuring resistor to calibrate them to the (true) lowest impedance of your sub. The Velleman M4307C has a readout to 1000W for 8Ohm.
Last edited:
ahh rats... I just did a quick search and found the vellman, and assumed it was just a volt meter. Sounds like 4pyros would need to calibrate it to his system, and he doesn't always use the full system... so impedance would be different some times. sounds like not a good idea.
A zener, a resistor and a LED has always worked for a 'danger' indicator... hmm... have to go looking for something a bit more clever than that.
Jim, your assumption that is works similar to a 'simple' voltmeter is more or less correct. Instead of just a zener diode and a resistor they added a transistor per led to 'switch' on the led by the corresponding voltage value. So every led + circuit works like an independent volt meter.
It’s just that the value of Volt or the Power changes by the impedance.
Power (Watts) as a stable factor;
100W = 28.3V @ 8Ohm
100W = 20.0V @ 4Ohm
100W = 14.1V @ 2Ohm
Or in case you want to use Volt as a stable factor;
28.3V = 100W @ 8Ohm
28.3V = 200W @ 4Ohm
28.3V = 400W @ 2Ohm
So in case he uses an Velleman power meter kit, instead of changing the measuring resistor he also can change the values of the watt readings (in other words don't use the printed display values that comes with the kit).
It’s just that the value of Volt or the Power changes by the impedance.
Power (Watts) as a stable factor;
100W = 28.3V @ 8Ohm
100W = 20.0V @ 4Ohm
100W = 14.1V @ 2Ohm
Or in case you want to use Volt as a stable factor;
28.3V = 100W @ 8Ohm
28.3V = 200W @ 4Ohm
28.3V = 400W @ 2Ohm
So in case he uses an Velleman power meter kit, instead of changing the measuring resistor he also can change the values of the watt readings (in other words don't use the printed display values that comes with the kit).
Last edited:
Hi
Pls let’s compare 2 drivers apparently good to habit THs:
Driver Mms BL
3015LF 93.4g 17
15TBX 163g 25.5
If we take a look at the cones we will know what the cone that will resist into the THs that have no restriction like, at the throat (follow screamersusa experience) or at mouth.
Tappedhorns I made are to reproduce lows,in the range 30/40Hz to 90/100Hz; so the drivers with high SPL numbers could work, but with limits; reach them and try to surpass it, you will Know what happens.
To better see how much the cone travels I put a white line label glued at the back of the cone (0,5cm x 5cm), which will give me a good reference of it as the power increases when testing.
In spite of low cut, the cone movement makes me fell warned. Also try and error makes me know that some drivers stay quieter then another, and the result with that one playing music will be better...
Thru a friend of mine was able to test some OEM drivers in THs. What a difference...
Have some information about loudspeaker factory that the drivers used by big speakers factories suffer from the same illness; so they receive some OEM developed drivers to their needs and to test them... Only when they decline from it, this driver will be at our disposal, if it.
Obviously these drivers are not at the balcony.
So we need to try with what we have at hand.
When the power limit is reached, the cone likes to travel to much.
This makes me remind about some of Mr.Danley’s comments, of how he develops a new project. The simulation is the only the guide; after it you have to made a prototype and try mods until you are satisfied with results.
Screamersusa I think makes the homework.
Weltersys chooses a good driver and worked at the opposed side of the horn and documented good results.
My past mistakes let me try to make it better next time; Also following what already functions gives me the way to go.
Regards,
Pls let’s compare 2 drivers apparently good to habit THs:
Driver Mms BL
3015LF 93.4g 17
15TBX 163g 25.5
If we take a look at the cones we will know what the cone that will resist into the THs that have no restriction like, at the throat (follow screamersusa experience) or at mouth.
Tappedhorns I made are to reproduce lows,in the range 30/40Hz to 90/100Hz; so the drivers with high SPL numbers could work, but with limits; reach them and try to surpass it, you will Know what happens.
To better see how much the cone travels I put a white line label glued at the back of the cone (0,5cm x 5cm), which will give me a good reference of it as the power increases when testing.
In spite of low cut, the cone movement makes me fell warned. Also try and error makes me know that some drivers stay quieter then another, and the result with that one playing music will be better...
Thru a friend of mine was able to test some OEM drivers in THs. What a difference...
Have some information about loudspeaker factory that the drivers used by big speakers factories suffer from the same illness; so they receive some OEM developed drivers to their needs and to test them... Only when they decline from it, this driver will be at our disposal, if it.
Obviously these drivers are not at the balcony.
So we need to try with what we have at hand.
When the power limit is reached, the cone likes to travel to much.
This makes me remind about some of Mr.Danley’s comments, of how he develops a new project. The simulation is the only the guide; after it you have to made a prototype and try mods until you are satisfied with results.
Screamersusa I think makes the homework.
Weltersys chooses a good driver and worked at the opposed side of the horn and documented good results.
My past mistakes let me try to make it better next time; Also following what already functions gives me the way to go.
Regards,
The plane that I have come up with for this week end is to use my PAA2 to measure the voltage at the speakers insted of a DVM. The PAA2 has peak hold and weighting.
Witch I think would be a more accurate measurement when using a music source.
Should I use A or C weighting when measuring voltage to determan power?
Andy
Witch I think would be a more accurate measurement when using a music source.
Should I use A or C weighting when measuring voltage to determan power?
Andy
Andy,
"A" scale rolls off starting at 1000 Hz, useless for sub measurement.
"C" scale rolls off below 100 Hz.
"Flat" or no weighting does not apply filters.
Over excursion messed up your drivers.
You need to measure the excursion while applying pink noise, and limit the power so the speaker's excursion does not exceed Xmax.
The only tools you need to accomplish that are your system, your eyes and a ruler, why do you keep trying to complicate the procedure?
Art
Attachments
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.