Sweep volume difference between amps

[Erod]

Question for you multiple separate amp users like me.

Is it normal for my sweep volume level to be so different from one amp to the other?
My one-year-old 225-watt x5 amp sweeps very loudly, while my 11-year-old 125-watt x7 amp sweeps not nearly as loud.

Is that because of the wattage differnce of the amps, or is that because of capacitors that have aged. It sounds great, but my level settings for the channels are just so different as a result.

 

[WaynePflughaupt]

With no more information that that, all that can be said is that the two amps have different input sensitivities.

Regards,
Wayne A. Pflughaupt

 

[Erod]

With no more information that that, all that can be said is that the two amps have different input sensitivities.

Regards,
Wayne A. Pflughaupt

My amps are a Anthem MCA 525 and a B&K Reference 125.7.

 

[Pogre]

My amps are a Anthem MCA 525 and a B&K Reference 125.7.

Like Wayne says, it most likely has something to do with the input sensitivity. More information would be very helpful though.

 

[Erod]

Like Wayne says, it most likely has something to do with the input sensitivity. More information would be very helpful though.

OK, I looked up the input sensitivity for each, and the Anthem has a 1.5V rating, and the B&K as a 2.0V rating.

So that likely explains it?

When I run ARC for my Anthem AVM60, the sweeps in the channels connected to the Anthem MCA 525 are really loud, while the sweeps for the speakers connected to the B&K are much quieter.

My concern was that my capacitors may be failing on the 11-year-old B&K amp, but the input sensitivity looks to be the culprit by the responses here.

 

[Leemix]

Have you looked at the gain on each of them


Sent from my iPad using Tapatalk

 

[PENG]

Is it normal for my sweep volume level to be so different from one amp to the other?
My one-year-old 225-watt x5 amp sweeps very loudly, while my 11-year-old 125-watt x7 amp sweeps not nearly as loud.

What do you mean by "your sweep volume level" and did you compare "loud" with a spl meter, REW, or just by ears?

Is that because of the wattage differnce of the amps, or is that because of capacitors that have aged. It sounds great, but my level settings for the channels are just so different as a result.

Not likely, most likely due to different amplifier gain/input sensitivity as others pointed out of the two amps. However, in checking their specs, the Anthem amp may be slightly (1 dB at the most) more sensitive so if you want to run Audyssey, YPAO etc., the level settings should be within 1 dB all else being equal (that is, same speakers in the same place, measuring mic in the same place, source input same etc.)

 

[Erod]

What do you mean by "your sweep volume level" and did you compare "loud" with a spl meter, REW, or just by ears?



Not likely, most likely due to different amplifier gain/input sensitivity as others pointed out of the two amps. However, in checking their specs, the Anthem amp may be slightly (1 dB at the most) more sensitive so if you want to run Audyssey, YPAO etc., the level settings should be within 1 dB all else being equal (that is, same speakers in the same place, measuring mic in the same place, source input same etc.)

When ARC is running sweeps through each channel, those connected to the Anthem amp are deafening. I have to cover my ears. For the other channels connected to the B&K, it is not nearly as loud.

 

[Pogre]

When ARC is running sweeps through each channel, those connected to the Anthem amp are deafening. I have to cover my ears. For the other channels connected to the B&K, it is not nearly as loud.

If you're running room correction and it does level adjustments, the end result should be pretty even between all of your speakers.

 

[PENG]

When ARC is running sweeps through each channel, those connected to the Anthem amp are deafening. I have to cover my ears. For the other channels connected to the B&K, it is not nearly as loud.

Thank you, that explains it. So I guess you are talking about sound you heard when running AARC with your AVM, or MRX. In that case, assuming the MCA powers the main 5 speakers and the B&K powers the ambient speakers. That would mean the LCR and the other two speakers have much higher sensitivity and the other surround/height speakers powered by the B&K has much lower sensitivity.

If you check the level settings after, you should find that levels for the speakers powered by the MCA amps much lower. That would be normal.

Just noticed Pogre beat me to it.

 

[Erod]

Thank you, that explains it. So I guess you are talking about the pink noise you heard when running ARC with your AVM, or MRX. In that case, assuming the MCA powers the main 5 speakers and the B&K powers the ambient speakers. That would mean the LCR and the other two speakers have much higher sensitivity and the other surround/height speakers powered by the B&K has much lower sensitivity.

If you check the level settings after, you should find that levels for the speakers powered by the MCA amps much lower. That would be normal.

Just noticed Pogre beat me to it.

That's where I'm confused. My side and rear channels are exactly the same inwall speakers (Jamo 626k4). However, the side channels are connected to the Anthem, and the rears are connected to the B&Ks. There's about a +4 difference in level settings afterward in the rears to get them all to 75 dB. (I'm referring to the room correction 20-20kHz sweeps, not the pink noise.)

My front LCR are RBH signature bookshelves, and yes, they do have a higher sensitivity. But the sides and rears are identical.

The end result sounds great. I'm just trying to figure out if my older amp is playing sweeps lower because of potential degrading in my capacitors, or if this is just normal due to the specs of each.

The Anthem XLR input sensitivity is 1.5V, and the gain is 29 dB. The B&K XLR input sensitivity is 2.0V, but I can't find a spec on the gain.

 

[Erod]

If you're running room correction and it does level adjustments, the end result should be pretty even between all of your speakers.

They do. I'm just trying to figure out why the sweeps that are run through each channel by Anthem Room Correction are so dramatically different in volume.

Is that what is should be with these amps, or is my older amp starting to degrade in some way?

 

[Pogre]

They do. I'm just trying to figure out why the sweeps that are run through each channel by Anthem Room Correction are so dramatically different in volume.

Is that what is should be with these amps, or is my older amp starting to degrade in some way?

It uses those sweeps to determine distances, SPL levels, maybe some EQ... point is, if things are even and sound good after running Room correction then I wouldn't worry about it.

 

[lovinthehd]

You can't determine a whole lot from the sweeps, especially about the amps final settings by the pre-pro afterwards. As was said it is testing for speaker sensitivity, necessary delay and levels for a final result. If the final result is fine you're just worrying unnecessarily.

 

[PENG]

That's where I'm confused. My side and rear channels are exactly the same inwall speakers (Jamo 626k4). However, the side channels are connected to the Anthem, and the rears are connected to the B&Ks. There's about a +4 difference in level settings afterward in the rears to get them all to 75 dB. (I'm referring to the room correction 20-20kHz sweeps, not the pink noise.)

My front LCR are RBH signature bookshelves, and yes, they do have a higher sensitivity. But the sides and rears are identical.

The end result sounds great. I'm just trying to figure out if my older amp is playing sweeps lower because of potential degrading in my capacitors, or if this is just normal due to the specs of each.

The Anthem XLR input sensitivity is 1.5V, and the gain is 29 dB. The B&K XLR input sensitivity is 2.0V, but I can't find a spec on the gain.

I edited my post, I said pink by mistake, of course you have been referring to "sweep" from the beginning. I downloaded the B&K manual, it says 28 dB gain and the Anthem is about 29 dB gain so that is a very minor factor.

As others posted, you can't just go by the sensitivity either, but also their placement. When you use a spl meter to check if they are all at 75 dB you should be using the pink noise and I guess you must have. Did you make sure you place your spl meter at the same position as the Anthem mic when runnning Anthem Room Correction.

Again, the slight difference in gain between the two amps, or deteriorated caps shouldn't have make such a difference, but you can easily prove the point by connecting one of the rears to the MCA and one of the front to the B&K and measure again to see if anything change. I bet any change would be within 1 dB, not 4.