XTI limiter question

[Bones]

In the XTI you can set the limiter by voltage which is great. But in every model XTI and in every setting (stereo,bridged) the max voltage shown is 56v. Im sure that my XTI 2002 puts out more than 56V bridged, that is about 800watts at 4ohms. Using the formula[(sqrt(watts x ohms)] the max output voltage of the 2002 should be 90v Is there any way for me to tell an accurate output voltage in system architect?


Side note: when checking voltage with a meter, you should always have a load on it right?

Edit: it goes up to 59 volts. Same issue though

[Grant Bunter]

In the XTI you can set the limiter by voltage which is great. But in every model XTI and in every setting (stereo,bridged) the max voltage shown is 56v. Im sure that my XTI 2002 puts out more than 56V bridged, that is about 800watts at 4ohms. Using the formula[(sqrt(watts x ohms)] the max output voltage of the 2002 should be 90v Is there any way for me to tell an accurate output voltage in system architect?


Side note: when checking voltage with a meter, you should always have a load on it right?

I don't know about the "always showing 56V" thing. Perhaps try "band manager" as well to see if it's the same in that programme.
A load is required for valve amps, but not solid state ones, so NO load.
Use the AC 200 setting (or whatever is closest) on your multimeter.

Why are you looking to bridge?

[Bones]

How will the amp know what kind of load i WILL be putting on it without testing it with that exact load? I will be putting a 4ohm load on it, so how do I know that the reading I get from the meter will be the voltage output @ a 4 ohms? (Sorry for these simple questions, Im not that electrical lol). I want to bridge my XTI 2002, but I only want to give out 55V. I could run in stereo but running this particular setup bridges makes it much more manageable for me.

[sine143]

why does bridged make things easier?

the xti 2002 does 55 volts on a single channel... (bridged it will do 110). The XTI's HATE being run at 2 ohms (or at 4 ohms bridged).... just saying.

[Grant Bunter]

How will the amp know what kind of load i WILL be putting on it without testing it with that exact load? I will be putting a 4ohm load on it, so how do I know that the reading I get from the meter will be the voltage output @ a 4 ohms? (Sorry for these simple questions, Im not that electrical lol). I want to bridge my XTI 2002, but I only want to give out 55V. I could run in stereo but running this particular setup bridges makes it much more manageable for me.

Your goal is to set a voltage limit for your drivers.
If you haven't set the voltage limit correctly and you load is applied (that is, you hooked up your cabs) you will most likely blow your drivers.

So that's why you don't test your amp limiting voltage with a load applied.

It can get more technical, but an amplifier will "see" the load applied to it.
Some people use what is called a dummy load to test.

BTW You will only get a 4ohm load on your amp if you have used lab12 drivers in your sub cabs, and you hook up 2 cabs in parallel on that channel.
The lab 12 has a nominal impedance of 6 ohms and there is an additional 2 ohms of acoustic impedance in Bill's sub designs due to the horn, making the impedance of the cab 8 ohms.
If you used 8 ohm nominal impedance drivers in your cabs then the nominal cab impedance is in fact 10 ohms and 2 in parallel on one channel will be 5 ohms overall.

If you used 4 ohm drivers then nominal cab impedance would be 6 ohms, 2 in parallel would = 3 ohms on the amp.

Suffice to say, setting up voltage levels with no load will be close enough (but never more than the required voltage) regardless of what cabs you put on your amp.

Read this from Bill about bridging:
http://billfitzmaurice.info/forum/viewt ... =6&t=19292

[Titanium Hand]

I'm unfamiliar with the newest model XTi's though I have an older model XTi 2000. The options for setting limiters are -3dB or -6dB.
Running the amp flat out, using only one channel, audacity tone generator and maxing out all of the gains and levels on my Traktor S2, the multimeter hits around 75 volts. You definitely want to set the limiters properly.

Probes straight into the red and black outputs in the back of amp, check the highest limit available on your amp and continue to reduce the limit until your multimeter DOES NOT exceed 50 volts. Job done - Crank it with peace of mind!