mini-X to power rear surrounds?

[garbulky]

Oct 27, 2013 18:02:21 GMT -5 Jim said:

Oct 27, 2013 17:59:32 GMT -5 garbulky said:

You will not have a problem with input overload in real life.
If you adjust the volume via the mini-x then you can send the maximum volume of your reciever to it no problem. If you adjust the volume with the reciever (and set the mini-x at maximum) then you will still not be overloading anything. When your mini-x maxes out, then it will max out just like any piece of equipment. But you won't be encountering situations where you've set your reciever to a normal volume and the output spikes due to dynamic range and the mini-x badly distorts because it has gone over the 600mv limit - not in regular listening. It just doesn't happen. The mini-x has dynamic range and then some.

But if you had low sensitivity speakers and were using the Mini-X and had it cranked up?

But yeah, realistically, surrounds just don't need the power 99% of the time.

I don't own a Mini-X, so I don't know how politely it handles over 600mv..

What I was saying is that the gain setting doesn't make the mini-x overload. Only when it itself runs out of power - like any amp. So even if it had 26 db gain, it will overload when it runs out of power at the same volume and power output. So the gain stage (at least in my experience - the upa-2 has 32 db gain) does not overload it during powerful dynamics. In fact, I haven't been able to make my UPA-2 (audibly) clip.
So what the OP is asking - and it's a reasonable question - my reciever can output X amount of volts much higher than the max voltage needed to drive the amps to full....since dynamics can take it up to 2V (or more) output wouldn't this be causing clipping in the mini-x?
The answer is to that is no. Because the mini-x will clip when it runs out of power not due to a 2V signal because it won't be seeing a 2V signal when you use whatever volum attenuation. You will be adjusting this 2V signal in some way (reciever or mini-x volume control) to keep it in the mini-x's power range - which is significant. So during this it will be experiencing less than 600mv. But at 600 mv it will be outputting its max. So just like any amp, after it gets to clipping it will clip but not just due the capabilities of a 2v signal.

I've used the UPA-2 with the XDA-1 (which had a peak output capability of 12 V with 1-2V nominal) and a USP-1 (9V peak). Neither of them clipped the amp due to an overenthusiastic voltage due to a high gain stage. They have the potential to clip - just like any other amp. But if you attenuate the volume to a normal listening volume then the dynamics will not clip the amp due to a high voltage output CAPABILITY. Now the mini-x does have a max power output and so you will experience its limits - just like another amp. But sending a 2V line signal to the mini-x and using the mini-x volume control will not overload it as the potentiometer will adjust it down.

[Jim]

Oct 27, 2013 18:43:11 GMT -5 garbulky said:

Oct 27, 2013 18:02:21 GMT -5 Jim said:

But if you had low sensitivity speakers and were using the Mini-X and had it cranked up?

But yeah, realistically, surrounds just don't need the power 99% of the time.

I don't own a Mini-X, so I don't know how politely it handles over 600mv..

What I was saying is that the gain setting doesn't make the mini-x overload. Only when it itself runs out of power - like any amp. So even if it had 26 db gain, it will overload when it runs out of power at the same volume and power output. So the gain stage (at least in my experience - the upa-2 has 32 db gain) does not overload it during powerful dynamics. In fact, I haven't been able to make my UPA-2 (audibly) clip.
So what the OP is asking - and it's a reasonable question - my reciever can output X amount of volts much higher than the max voltage needed to drive the amps to full....since dynamics can take it up to 2V (or more) output wouldn't this be causing clipping in the mini-x?
The answer is to that is no. Because the mini-x will clip when it runs out of power not due to a 2V signal because it won't be seeing a 2V signal when you use whatever volum attenuation. You will be adjusting this 2V signal in some way (reciever or mini-x volume control) to keep it in the mini-x's power range - which is significant. So during this it will be experiencing less than 600mv. But at 600 mv it will be outputting its max. So just like any amp, after it gets to clipping it will clip but not just due the capabilities of a 2v signal.

I've used the UPA-2 with the XDA-1 (which had a peak output capability of 12 V with 1-2V nominal) and a USP-1 (9V peak). Neither of them clipped the amp due to an overenthusiastic voltage due to a high gain stage. They have the potential to clip - just like any other amp. But if you attenuate the volume to a normal listening volume then the dynamics will not clip the amp due to a high voltage output CAPABILITY. Now the mini-x does have a max power output and so you will experience its limits - just like another amp. But sending a 2V line signal to the mini-x and using the mini-x volume control will not overload it as the potentiometer will adjust it down.

Nicely stated!

[unsound]

Oct 27, 2013 18:43:11 GMT -5 garbulky said:

Oct 27, 2013 18:02:21 GMT -5 Jim said:

But if you had low sensitivity speakers and were using the Mini-X and had it cranked up?

But yeah, realistically, surrounds just don't need the power 99% of the time.

I don't own a Mini-X, so I don't know how politely it handles over 600mv..

What I was saying is that the gain setting doesn't make the mini-x overload. Only when it itself runs out of power - like any amp. So even if it had 26 db gain, it will overload when it runs out of power at the same volume and power output. So the gain stage (at least in my experience - the upa-2 has 32 db gain) does not overload it during powerful dynamics. In fact, I haven't been able to make my UPA-2 (audibly) clip.
So what the OP is asking - and it's a reasonable question - my reciever can output X amount of volts much higher than the max voltage needed to drive the amps to full....since dynamics can take it up to 2V (or more) output wouldn't this be causing clipping in the mini-x?
The answer is to that is no. Because the mini-x will clip when it runs out of power not due to a 2V signal because it won't be seeing a 2V signal when you use whatever volum attenuation. You will be adjusting this 2V signal in some way (reciever or mini-x volume control) to keep it in the mini-x's power range - which is significant. So during this it will be experiencing less than 600mv. But at 600 mv it will be outputting its max. So just like any amp, after it gets to clipping it will clip but not just due the capabilities of a 2v signal.

I've used the UPA-2 with the XDA-1 (which had a peak output capability of 12 V with 1-2V nominal) and a USP-1 (9V peak). Neither of them clipped the amp due to an overenthusiastic voltage due to a high gain stage. They have the potential to clip - just like any other amp. But if you attenuate the volume to a normal listening volume then the dynamics will not clip the amp due to a high voltage output CAPABILITY. Now the mini-x does have a max power output and so you will experience its limits - just like another amp. But sending a 2V line signal to the mini-x and using the mini-x volume control will not overload it as the potentiometer will adjust it down.

I think the OP just asked about where to set the volume knob. Jim and I started on the whole 2V thing a bit later.

Ok, let me try and understand something. People were saying to run the mini-X at full volume. In this situation if I send a 2V line signal, which potentiometer is adjusting it down?

I believe you're essentially saying the mini-X has enough power for his application, is that correct? That may be true, I just don't know the specifics of his situation.

I somewhat agree with the gain setting not making the mini-x overload. This is making the assumption that at the end of it you'll be listening at X dB - same speaker loudness regardless of volume setting on the mini. In that case, yes, the amp will run out of power either way. However, it will take a much higher volume setting on the preamp to cause the mini to run out of power. So, I can also state, that the gain setting on the mini will make it overload assuming a fixed level of volume from the preamp. That is, I turn the volume on the preamp high enough to where it will clip the mini at full volume but not clip the mini at half volume, yes?

I've never clipped my UPA-2 either running bookshelves, but I have clipped my Crown XLS running my Revel F32s in a 35x20 room. I've lowered the gain on my Crown to where the UMC-1 will not clip it even at full volume. This is just to avoid accidental clipping as can happen when 2 different sources have very different levels.

[garbulky]

Oct 27, 2013 19:37:44 GMT -5 unsound said:

Oct 27, 2013 18:43:11 GMT -5 garbulky said:

What I was saying is that the gain setting doesn't make the mini-x overload. Only when it itself runs out of power - like any amp. So even if it had 26 db gain, it will overload when it runs out of power at the same volume and power output. So the gain stage (at least in my experience - the upa-2 has 32 db gain) does not overload it during powerful dynamics. In fact, I haven't been able to make my UPA-2 (audibly) clip.
So what the OP is asking - and it's a reasonable question - my reciever can output X amount of volts much higher than the max voltage needed to drive the amps to full....since dynamics can take it up to 2V (or more) output wouldn't this be causing clipping in the mini-x?
The answer is to that is no. Because the mini-x will clip when it runs out of power not due to a 2V signal because it won't be seeing a 2V signal when you use whatever volum attenuation. You will be adjusting this 2V signal in some way (reciever or mini-x volume control) to keep it in the mini-x's power range - which is significant. So during this it will be experiencing less than 600mv. But at 600 mv it will be outputting its max. So just like any amp, after it gets to clipping it will clip but not just due the capabilities of a 2v signal.

I've used the UPA-2 with the XDA-1 (which had a peak output capability of 12 V with 1-2V nominal) and a USP-1 (9V peak). Neither of them clipped the amp due to an overenthusiastic voltage due to a high gain stage. They have the potential to clip - just like any other amp. But if you attenuate the volume to a normal listening volume then the dynamics will not clip the amp due to a high voltage output CAPABILITY. Now the mini-x does have a max power output and so you will experience its limits - just like another amp. But sending a 2V line signal to the mini-x and using the mini-x volume control will not overload it as the potentiometer will adjust it down.

I think the OP just asked about where to set the volume knob. Jim and I started on the whole 2V thing a bit later.

Ok, let me try and understand something. People were saying to run the mini-X at full volume. In this situation if I send a 2V line signal, which potentiometer is adjusting it down?

I believe you're essentially saying the mini-X has enough power for his application, is that correct? That may be true, I just don't know the specifics of his situation.

I somewhat agree with the gain setting not making the mini-x overload. This is making the assumption that at the end of it you'll be listening at X dB - same speaker loudness regardless of volume setting on the mini. In that case, yes, the amp will run out of power either way. However, it will take a much higher volume setting on the preamp to cause the mini to run out of power. So, I can also state, that the gain setting on the mini will make it overload assuming a fixed level of volume from the preamp. That is, I turn the volume on the preamp high enough to where it will clip the mini at full volume but not clip the mini at half volume, yes?

I've never clipped my UPA-2 either running bookshelves, but I have clipped my Crown XLS running my Revel F32s in a 35x20 room. I've lowered the gain on my Crown to where the UMC-1 will not clip it even at full volume. This is just to avoid accidental clipping as can happen when 2 different sources have very different levels.

Ok, let me try and understand something. People were saying to run the mini-X at full volume. In this situation if I send a 2V line signal, which potentiometer is adjusting it down?

- The mini-X

I somewhat agree with the gain setting not making the mini-x overload. This is making the assumption that at the end of it you'll be listening at X dB - same speaker loudness regardless of volume setting on the mini. In that case, yes, the amp will run out of power either way. However, it will take a much higher volume setting on the preamp to cause the mini to run out of power. So, I can also state, that the gain setting on the mini will make it overload assuming a fixed level of volume from the preamp. That is, I turn the volume on the preamp high enough to where it will clip the mini at full volume but not clip the mini at half volume, yes?


- I assume that it will clip but I don't know where it's limits are or how it behaves past that limit. But the answer is likely, yes. However, if you are running the surrounds as the OP wants to then he will have to adjust the output levels to be equivalent so any gain levels are matched. So one isn't louder than the other.

I've never clipped my UPA-2 either running bookshelves, but I have clipped my Crown XLS running my Revel F32s in a 35x20 room. I've lowered the gain on my Crown to where the UMC-1 will not clip it even at full volume. This is just to avoid accidental clipping as can happen when 2 different sources have very different levels.

- I'm not sure what you mean here. Are you talking about running your speakers at line level volumes/full volumes or assuming that's what the OP may possibly do? Is that what you were cautioning against - clipping at line level volumes? If so, I wouldn't reccomend the mini-x for something like that at all. I would reccomend ear muffs.
Hehe but in seriousness, if that's the application, they would need amps with lots of grunt (as well as speakers).

But if the OP is buying a mini-x most likely, that's not what he's going for. Hes simply asking which is the best way to do volume. And the answer to that is depends on how good the volume control on the reciever is but likely for convenience it will be the receiver controlling it unless he can figure out how to match the levels with the mini-x volume control.

[unsound]

Oct 27, 2013 21:51:02 GMT -5 garbulky said:

Ok, let me try and understand something. People were saying to run the mini-X at full volume. In this situation if I send a 2V line signal, which potentiometer is adjusting it down?

- The mini-X

Hmmm...I didn't realize there was another potentiometer outside of the volume control that's adjusting the input voltage. I'm assuming that since it's a potentiometer and not an attenuator, it has a variable impact on the input voltage. I don't know that much about amps, but this seems strange to me - will this not "color" the sound? Or, are you saying that even at full volume on the mini there is some (not insignificant) attenuation that's happening on the input voltage?

Oct 27, 2013 21:51:02 GMT -5 garbulky said:

I somewhat agree with the gain setting not making the mini-x overload. This is making the assumption that at the end of it you'll be listening at X dB - same speaker loudness regardless of volume setting on the mini. In that case, yes, the amp will run out of power either way. However, it will take a much higher volume setting on the preamp to cause the mini to run out of power. So, I can also state, that the gain setting on the mini will make it overload assuming a fixed level of volume from the preamp. That is, I turn the volume on the preamp high enough to where it will clip the mini at full volume but not clip the mini at half volume, yes?


- I assume that it will clip but I don't know where it's limits are or how it behaves past that limit. But the answer is likely, yes. However, if you are running the surrounds as the OP wants to then he will have to adjust the output levels to be equivalent so any gain levels are matched. So one isn't louder than the other.

I've never clipped my UPA-2 either running bookshelves, but I have clipped my Crown XLS running my Revel F32s in a 35x20 room. I've lowered the gain on my Crown to where the UMC-1 will not clip it even at full volume. This is just to avoid accidental clipping as can happen when 2 different sources have very different levels.

- I'm not sure what you mean here. Are you talking about running your speakers at line level volumes/full volumes or assuming that's what the OP may possibly do? Is that what you were cautioning against - clipping at line level volumes? If so, I wouldn't reccomend the mini-x for something like that at all. I would reccomend ear muffs.
Hehe but in seriousness, if that's the application, they would need amps with lots of grunt (as well as speakers).

Well, yes. I did run the UMC at close to full volume and slowly increased the gain on my amp to where it got close to clipping. That's where I left the gain on the amp. To my understanding this leads to the situation where the full output of my preamp just about maxes out my amp. I'm not sure where I read this, but it was the recommend way to match gains on preamps and amps. Of course, it's convenient that the Crown comes with a clipping indicator.

[garbulky]

Oct 28, 2013 11:51:39 GMT -5 unsound said:

Oct 27, 2013 21:51:02 GMT -5 garbulky said:

Ok, let me try and understand something. People were saying to run the mini-X at full volume. In this situation if I send a 2V line signal, which potentiometer is adjusting it down?

- The mini-X

Hmmm...I didn't realize there was another potentiometer outside of the volume control that's adjusting the input voltage. I'm assuming that since it's a potentiometer and not an attenuator, it has a variable impact on the input voltage. I don't know that much about amps, but this seems strange to me - will this not "color" the sound? Or, are you saying that even at full volume on the mini there is some (not insignificant) attenuation that's happening on the input voltage?

The mini-x has a volume knob. I assume it is a stereo potentiometer. It adjust the volume or you can leave it maxed out. Most things you do to reduce the volume from maximum will color the sound in some way or the other. In this case, the most coloring you will get is a channel imbalance at very low volumes. I think the crown uses a similar method - likely two mono potentiometers to adjust its gain.
Usually recievers use a digital attenuation method and these methods are lossy as they lose audio resolution as you turn them down from maximum. So analog attenuation is more desirable unless the digital attenuation is done "right".

[unsound]

Now, I'm confused. Sure, I expect the volume knob to be a potentiometer. But, I'd asked what potentiometer is affecting the input signal when the mini-x volume is set to max and you said "The mini-x". So, I thought you were saying there is another potentiometer other than the volume control. But, now it seems like the potentiometer you're talking about is the volume pot.

So, since he's using a receiver and it is expected to have lossy digital attenuation, wouldn't it be better to use the mini-x volume control anyway rather than letting the mini-x run at full volume?

[boomzilla]

Mini-X to power rear surrounds? In a word, YES!

[unsound]

I just got done with setting it up that way. I still haven't calibrated it yet. I was hoping to use the "Auto" setting on the mini-x so it would only come on only when there actually was program material to the rears. But, it looks like the delay in it turning on after the signal is 2-3 seconds. This is what I saw when I quickly ran through the speaker level settings on the UMC-1. I will check again later when I have more time, unless someone can confirm that it does indeed take 2-3 seconds in Auto mode.

[garbulky]

Oct 29, 2013 13:22:05 GMT -5 unsound said:

Now, I'm confused. Sure, I expect the volume knob to be a potentiometer. But, I'd asked what potentiometer is affecting the input signal when the mini-x volume is set to max and you said "The mini-x". So, I thought you were saying there is another potentiometer other than the volume control. But, now it seems like the potentiometer you're talking about is the volume pot.

So, since he's using a receiver and it is expected to have lossy digital attenuation, wouldn't it be better to use the mini-x volume control anyway rather than letting the mini-x run at full volume?

Sorry, I'm being confusing! If the mini-x is set at max you will need to use the reciever to control the volume or it will be too loud (as the reciever would be set at max). Most (but not all) recievers use digital attenuation and most of them don't use 32 bit digital attenuation.
As for the question would it be better to use the mini- control anyway due to digital attenuation. It would be kind of long to type the response but the basic thing is that if you use the mini-x volume knob to control only the rear surround it won't work out correctly in terms of balancing the other speakers volume - and it will be also cumbersome vs using the remote control of the reciever.
If he uses it for the rears then I think the most he would use the mini-x volume control is a set and forget setting to level match it with the gain and speaker efficiencies of the other speakers in the setup.

[unsound]

Oct 30, 2013 2:13:21 GMT -5 garbulky said:

Oct 29, 2013 13:22:05 GMT -5 unsound said:

Now, I'm confused. Sure, I expect the volume knob to be a potentiometer. But, I'd asked what potentiometer is affecting the input signal when the mini-x volume is set to max and you said "The mini-x". So, I thought you were saying there is another potentiometer other than the volume control. But, now it seems like the potentiometer you're talking about is the volume pot.

So, since he's using a receiver and it is expected to have lossy digital attenuation, wouldn't it be better to use the mini-x volume control anyway rather than letting the mini-x run at full volume?

Sorry, I'm being confusing! If the mini-x is set at max you will need to use the reciever to control the volume or it will be too loud (as the reciever would be set at max). Most (but not all) recievers use digital attenuation and most of them don't use 32 bit digital attenuation.
As for the question would it be better to use the mini- control anyway due to digital attenuation. It would be kind of long to type the response but the basic thing is that if you use the mini-x volume knob to control only the rear surround it won't work out correctly in terms of balancing the other speakers volume - and it will be also cumbersome vs using the remote control of the reciever.
If he uses it for the rears then I think the most he would use the mini-x volume control is a set and forget setting to level match it with the gain and speaker efficiencies of the other speakers in the setup.

Ha, my turn to be confusing I guess - sorry about that! That is what I meant - using the mini-x volume as a set and forget - just not necessarily at full volume. Essentially this whole discussion started with a few people suggesting using the mini-x at full volume and then I said there may be reasons not to have it at full volume. I think it's pretty well discussed at this point! I ended up setting mine at the 3 PM position.