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post #1 of 15 Old 08-13-2015, 12:37 PM - Thread Starter
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Setting external amp gain?

I've got a pair of mono block amps to drive my front L/R mains from pre-outs on my AVR. They both have a knob on them to adjust the gain. I'm guessing the best approach to setting the gain on an external amp (such as these) is to follow the same practise normally applied to sub-woofers...

- Set the gain to about mid-way
- Run room calibration and note the levels applied by software
- Adjust amp gain up or down until the calibration is applying 0 adjustment to levels

Or is there some other way?
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post #2 of 15 Old 08-13-2015, 12:50 PM
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That should do it, but subs are generally far more efficient than speakers, so you'll need to likely raise the gain to at least 80% of max.

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post #3 of 15 Old 08-13-2015, 01:40 PM - Thread Starter
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Quote:
Originally Posted by jdsmoothie View Post
That should do it, but subs are generally far more efficient than speakers, so you'll need to likely raise the gain to at least 80% of max.
Roger that... thanks!
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post #4 of 15 Old Yesterday, 01:54 AM
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Quote:
Originally Posted by virtualrain View Post
I've got a pair of mono block amps to drive my front L/R mains from pre-outs on my AVR. They both have a knob on them to adjust the gain. I'm guessing the best approach to setting the gain on an external amp (such as these) is to follow the same practise normally applied to sub-woofers...

- Set the gain to about mid-way
- Run room calibration and note the levels applied by software
- Adjust amp gain up or down until the calibration is applying 0 adjustment to levels

Or is there some other way?
Yes, there's another way if you're keen.

To optimise the performance of your new amps with the AVR, you'll need to take a deep dive into setting up the gain structure. The most comprehensive explanation and process I've seen on the subject - and admittedly I don't fully understand it myself - is this excellent multi-part sticky on HTS by @Wayne A. Pflughaupt .

Gain Structure for Home Theater: Getting the Most from Pro Audio Equipment in Your System

Happy gain structuring!
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post #5 of 15 Old Yesterday, 05:00 PM
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Thanks for the kind words, Giegar.

Virtual, no need to wade through the whole article. Since you’re using your AVR as the pre-amp you can just gain-match the new amps to the AVR’s internal amp. You can find the “how two” on that in Part 8.

Regards,
Wayne A. Pflughaupt
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post #6 of 15 Old Today, 08:45 AM
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Thanks for dropping in Wayne. Thanks also for the tip that the "dive" doesn't have to be quite as "deep" as I indicated for proper gain-matching.

Your article has been my go-to reference for anyone enquiring about integrating pro amps into a home theatre system. The following quote is the crux of it for me, and you do a great job of proving it in your article.

Quote:
Unfortunately, the maximum-levels canon is ill-advised and naive. The truth is that going to extraordinary lengths to max out the low-level signal fed from a home theater AVR to downstream professional gear, especially by using external signal-boosting devices, is often unnecessary and can even be detrimental to achieving optimal dynamic range. As it turns out, gain structure suitable for a mixed pro/consumer system is relatively easy to attain and seldom requires anything in the way of extraneous signal manipulation.


[BTW: My 10 year old son (a budding bassist) and I were both very impressed with your bass rig and beautiful basses shown in the article linked in your signature.]
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post #7 of 15 Old Today, 10:52 AM - Thread Starter
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Quote:
Originally Posted by Wayne A. Pflughaupt View Post

Thanks for the kind words, Giegar.

Virtual, no need to wade through the whole article. Since you’re using your AVR as the pre-amp you can just gain-match the new amps to the AVR’s internal amp. You can find the “how two” on that in Part 8.

Regards,
Wayne A. Pflughaupt
Is that the part where you drive one channel through the AVR amp and one through the external amp with pink noise and match the SPL?
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post #8 of 15 Old Today, 12:51 PM
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Driving speakers actually, but yes that’s it.

Regards,
Wayne A. Pflughaupt
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post #9 of 15 Old Today, 01:06 PM - Thread Starter
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Quote:
Originally Posted by Wayne A. Pflughaupt View Post

Driving speakers actually, but yes that’s it.

Regards,
Wayne A. Pflughaupt

Ok. Yeah. That's what I meant. It's definitely an easy way to do it. And I guess for someone that doesn't have an SPL meter, they can do a best guess by ear and then run the room calibration routine in this way to see what it wants to set the level on the Amp channel to and adjust by trial and error until both channels are the same.

Ps. The guide isn't all that clear to be honest. That one paragraph is essential but buried in a section on measuring noise v
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post #10 of 15 Old Today, 01:17 PM
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Sure, you can be get in the ballpark by ear, and the AVR will take care of the rest.


Quote:
Originally Posted by virtualrain View Post
Ps. The guide isn't all that clear to be honest. That one paragraph is essential but buried in a section on measuring noise v
Understandable. However, the focal point of that section is determining background noise levels of outboard professional gear, not a how-to on level-matching an AVR to an outboard amp per se.

Regards,
Wayne A. Pflughaupt
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post #11 of 15 Old Today, 02:22 PM
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Quote:
Originally Posted by GIEGAR View Post
Thanks for dropping in Wayne. Thanks also for the tip that the "dive" doesn't have to be quite as "deep" as I indicated for proper gain-matching.
Almost didn’t see your post, I sure wish AVS would fix their e-mail notification issues. It’s going on a year now - ridiculous.

But yeah, it’s much easier with an AVR as the front end as you have the internal amps as a reference for setting gains on an outboard amp. As long as the AVR has enough output voltage to drive the amp that is...


Quote:
Your article has been my go-to reference for anyone enquiring about integrating pro amps into a home theatre system.
Thanks again for the kind words, Giegar.


Quote:
The following quote is the crux of it for me, and you do a great job of proving it in your article.

Quote:
Unfortunately, the maximum-levels canon is ill-advised and naive. The truth is that going to extraordinary lengths to max out the low-level signal fed from a home theater AVR to downstream professional gear, especially by using external signal-boosting devices, is often unnecessary and can even be detrimental to achieving optimal dynamic range. As it turns out, gain structure suitable for a mixed pro/consumer system is relatively easy to attain and seldom requires anything in the way of extraneous signal manipulation.
Yeah, don’t know how long you’ve been hanging around the home theater forums, but it used to be everyone and his dog was saying “boost the signal,” especially when it came to digital processors like the Behringer DCX, and everyone else was buying it and passing it along to others. It was in on all the forums (or at least the ones I visited). However, I’ve noticed that you never see anyone floating that song and dance anymore. In fact, I can’t hardly find the “boost the signal” references I quoted in the article (i.e. dropping the quote into Google). It’s like everyone who wrote that stuff went back and deleted it after the article came out! If I had a part in putting that mythology out to pasture, I’m happy!


Quote:
[BTW: My 10 year old son (a budding bassist) and I were both very impressed with your bass rig and beautiful basses shown in the article linked in your signature.]
Thanks again! Kudos to the kid, he’s getting an early start. I think I was 12-13. Tell him to practice, practice, practice. You’ll never have the time to practice like you do when you’re young. I cut my teeth playing records and learning the bass parts (yes I’m that old).

I’ve made a few additions to “the family” that the two of you might like. Last time I tried to update the HT Shack page it wouldn’t let me for some reason, but my signature on the page linked below has links to close-ups of the new basses. It’s one of the niceties of being older with the kids out of the house, finally being able to afford some toys. I never had more than one bass at a time until a few years ago.

My Basses

Regards,
Wayne A. Pflughaupt
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post #12 of 15 Old Today, 02:36 PM
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Quote:
Originally Posted by virtualrain View Post

I've got a pair of mono block amps...
What is their input sensitivity?

I'll be back later...


links::: 1.5RQ > digits > 1177a > OpenDRC-DI > DEQ2496 > DAC2 > KCT > FPB 350mcx > reQuest + Cheezewoofer Wattless Deluxe > Sweetspot
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post #13 of 15 Old Today, 02:46 PM - Thread Starter
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Originally Posted by RayDunzl View Post
What is their input sensitivity?

Not specified... But reviews from others seem to indicate they interface well with consumer AVRs or other devices...

http://www.daytonaudio.com/index.php...amplifier.html
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post #14 of 15 Old Today, 03:29 PM
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1V sensitivity is mentioned in the Q&A here.

I'll be back later...


links::: 1.5RQ > digits > 1177a > OpenDRC-DI > DEQ2496 > DAC2 > KCT > FPB 350mcx > reQuest + Cheezewoofer Wattless Deluxe > Sweetspot
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post #15 of 15 Unread Today, 04:07 PM
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if you bridge 2 amps together? should you adjust the gain on each individual amp? i have been happy with both my amps bridged and gain at 0...but in back of mind wonder if i should tweak with each amp gain controls? dont mean to hijack, just thinking this might apply here.

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