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Post by boomzilla on Mar 22, 2020 5:33:08 GMT -5
I've determined that the following setup will provide me with 3.0 sound and my two stereo subs can be driven from the R/L signals. To hear stereo with subs (2.2) I just use the #1 inputs on the preamp, and the Oppo is totally bypassed. To listen to a movie, swap the preamp to its #2 inputs, set the preamp to a pre-determined volume (matching the center channel amp's gain), and then control the master volume from the Oppo.  |
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Post by boomzilla on Mar 23, 2020 11:15:23 GMT -5
I may have solved it! Using these for the satellite power amps:  And using the plate amp crossover on the subs to match |
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Post by jackfish on Mar 23, 2020 23:37:03 GMT -5
Harrison Labs saves the day again!
13.3" MacBook Air, 4GB RAM, 256GB SSD, iTunes/BitPerfect
MacBook Air SuperDrive
Western Digital My Book Essential 2TB USB HD
Schiit Bifrost USB DAC and Audioengine D3 DAC
Emotiva USP-1, ERC-1 and two UPA-1s
Pro-Ject Xpression III and AT440MLa
AKAI AT-2600 and Harman Kardon TD4400
Grado SR80i
Wharfedale Diamond 225
Magnestand MMG
Rythmik Audio F12
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Post by boomzilla on Mar 24, 2020 9:31:49 GMT -5
Harrison Labs saves the day again! Although Harrison Labs DOES offer quite a variety of products, their inline passive crossovers are designed for a specific amplifier input impedance (10K ohms, if I remember right?). If your amp has a significantly different input impedance (my Emo PA-1's for example have 47K-ohms and my Heathkit tube amps have 325K-ohms), then the crossover point and the slope will drift quite a bit. This can be calculated (159,155 / RC = F for first order slopes), but the Harrison Labs products are second order. That can also be easily calculated, but parts variation becomes a MUCH larger factor for such calculations. It's easier to just throw the inline crossover into the system, and then measure with an analyzer to see where the actual roll-off occurs. The GOOD thing about the Harrison crossovers is that they're CHEAP. You can try several until you find the one that works most closely to the parameters you want. If I really wanted to get twerky with the project, I'd just build a board, roll off the PA-1 amps with a single capacitor at 6dB / octave, and then throw in a second cap for the subs, rolling them off at 6dB at the same frequency. Then, I'd use the sub plate amps to provide an additional 12dB / octave roll-off on the low-pass. That way, the mains would gently roll off while the subs would roll off at 18dB/octave (combined slope) keeping them from muddying the frequencies above their crossover point. |
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KeithL
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Post by KeithL on Mar 24, 2020 9:50:59 GMT -5
That's true... but it doesn't make as much difference as you might think.... and you can often easily compensate for it. First off, I've never looked inside one, but I suspect that the H-Labs modules have a pair of cascaded R/C stages inside. If so, then the second stage makes up the load for the first stage, which reduces the impact of a mismatch by the external load. (And makes your calculations more complicated  .) Second, if you really want a good match to your Emo amp, with its 47k input impedance..... Then all you need to do is to parallel a resistor with the input to make it the expected 10k load..... If you parallel a 13k resistor with that 47k input the result will be 10k within 2%. (For that Heathkit amp, I'd just add a 10k resistor in parallel, and call it "close enough".)
Also, if you buy one of THESE instead, you can try all sorts of different settings simply by moving the jumpers... And, yes, you can have a lot more fun, if you start trying fancy stuff...
[EDIT: I suppose I should add that, if you have a TUBE preamp, without a cathode follower output, then it probably won't appreciate driving a 10k load.  ] Harrison Labs saves the day again! Although Harrison Labs DOES offer quite a variety of products, their inline passive crossovers are designed for a specific amplifier input impedance (10K ohms, if I remember right?). If your amp has a significantly different input impedance (my Emo PA-1's for example have 47K-ohms and my Heathkit tube amps have 325K-ohms), then the crossover point and the slope will drift quite a bit. This can be calculated (159,155 / RC = F for first order slopes), but the Harrison Labs products are second order. That can also be easily calculated, but parts variation becomes a MUCH larger factor for such calculations. It's easier to just throw the inline crossover into the system, and then measure with an analyzer to see where the actual roll-off occurs. The GOOD thing about the Harrison crossovers is that they're CHEAP. You can try several until you find the one that works most closely to the parameters you want. If I really wanted to get twerky with the project, I'd just build a board, roll off the PA-1 amps with a single capacitor at 6dB / octave, and then throw in a second cap for the subs, rolling them off at 6dB at the same frequency. Then, I'd use the sub plate amps to provide an additional 12dB / octave roll-off on the low-pass. That way, the mains would gently roll off while the subs would roll off at 18dB/octave (combined slope) keeping them from muddying the frequencies above their crossover point. |
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DYohn
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Post by DYohn on Mar 24, 2020 10:40:17 GMT -5
If you want to watch movies get a home theater processor and stop f*king around.
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Deleted
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Post by Deleted on Mar 24, 2020 10:48:31 GMT -5
If you want to watch movies get a home theater processor and stop f*king around. Reminds me of why I think it desirable to have presets for various configurations or various options such as "music", "movies", etc. By your response I take it that some gear can't scale upwards for multi channel theater but from my experience with personally owned AV Pre-Pros they can scale downwards. |
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Post by boomzilla on Mar 24, 2020 15:08:36 GMT -5
If you want to watch movies get a home theater processor and stop f*king around. LOL - may be the best option... |
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Post by rbk123 on Mar 24, 2020 15:52:45 GMT -5
If you want to watch movies get a home theater processor and stop f*king around. No go. 2 months later some other rube goldberg idea, which will for sure sound the best this time, will catch his fancy and he'll have to sell it.
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Post by monkumonku on Mar 24, 2020 16:20:16 GMT -5
If you want to watch movies get a home theater processor and stop f*king around. LOL - may be the best option... Yeah, like if there is this big rock in the road and everyone makes all these really fancy plans of best ways to drive around the rock, like alternate routes, building a bridge over it, moving the destination so the rock is no longer an obstacle, etc... Then someone says, why don't you just get rid of the rock?  |
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Post by boomzilla on Mar 24, 2020 17:27:23 GMT -5
Analogies fail, thanks very much. There are "other factors" to be considered. And the primary one is sound quality. I didn't buy premium speakers, subwoofers, streamers, and DACs to listen to a pile of AV droppings. And I'll state unequivocally that good stereo separates sound better than any AV processor or receiver I've yet heard. I've tried again and again to get both premium quality stereo and movie performance from the same processor, and consistently failed. The AV stuff just does NOT sound as good. Now in theory, I could triple the number of wires and switches in the system and get a discreet stereo system and a discreet movie system - after all Mr. Mark Kline has done so - but I'm also required to maintain a certain simplicity to the system. When a component arrives for review, I never know what it might be, and everything has to move around to work with the review component.
If the Oppo was working as designed, I could pull off the setup in the original post and get where I need to be. But repair is somewhere in the (post virus) future.
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Deleted
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Post by Deleted on Mar 24, 2020 18:14:33 GMT -5
Analogies fail, thanks very much. There are "other factors" to be considered. And the primary one is sound quality. I didn't buy premium speakers, subwoofers, streamers, and DACs to listen to a pile of AV droppings. And I'll state unequivocally that good stereo separates sound better than any AV processor or receiver I've yet heard. I've tried again and again to get both premium quality stereo and movie performance from the same processor, and consistently failed. The AV stuff just does NOT sound as good. Now in theory, I could triple the number of wires and switches in the system and get a discreet stereo system and a discreet movie system - after all Mr. Mark Kline has done so - but I'm also required to maintain a certain simplicity to the system. When a component arrives for review, I never know what it might be, and everything has to move around to work with the review component. If the Oppo was working as designed, I could pull off the setup in the original post and get where I need to be. But repair is somewhere in the (post virus) future. Hey Boom, Onkyo has a feature in their flagship pre-pro that I'm not sure whether pretty standard throughout the industry. A pure audio button. Again I'm not sure about what is going on etc when using the feature. In the config I'm setup up for 3.1 listening but hitting the button shuts down the center and subwoofer. I also don't use the the AccuEq other than setup for distance and levels. I turn the EQ off because I don't like the sound of the EQ. Just how much "processing" I use I think minimum but no doubt utilize some for the 3 channel config. I'm guessing more processing is used when scaling recorded stereo music upwards than multi channel formats during AV playback. I take it that the pure audio option turns off processing and plays the recording as is like running a media player directly to the amp. Crossover etc must be disabled as the sub and center are turned off and L as well as R go to full range. Just pointing out the system can scale down and upwards in AV mode utilizing various channels in formats or recording. If you like analogies the stereo signal doesn't have the required info for multi channels or like a virus is incapable of binding to receptors of another species [horizontal] or genus [vertical] to upscale. A mutation has to occur adding information. That's the beauty of the AV processor. Enjoy, William |
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Post by 405x5 on Mar 25, 2020 10:40:35 GMT -5
I've determined that the following setup will provide me with 3.0 sound and my two stereo subs can be driven from the R/L signals. To hear stereo with subs (2.2) I just use the #1 inputs on the preamp, and the Oppo is totally bypassed. To listen to a movie, swap the preamp to its #2 inputs, set the preamp to a pre-determined volume (matching the center channel amp's gain), and then control the master volume from the Oppo. All that effort and no back channels?? |
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Post by boomzilla on Mar 25, 2020 15:55:36 GMT -5
All that effort and no back channels?? Easily added with one more stereo amp and two speakers (all of which I have lying around...). |
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Post by creimes on Mar 25, 2020 16:48:18 GMT -5
If you want to watch movies get a home theater processor and stop f*king around. LOL - may be the best option... or find a used one on the used market, my XMC-1 is rock solid though it is 1.4 HDMI board haha and 2ch sounds really really good for a processor |
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Post by 405x5 on Mar 25, 2020 18:41:38 GMT -5
All that effort and no back channels?? Easily added with one more stereo amp and two speakers (all of which I have lying around...). No discreet back channels without processing |
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klinemj
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Post by klinemj on Mar 25, 2020 19:01:31 GMT -5
If you want to watch movies get a home theater processor and stop f*king around. LOL - may be the best option... It is, but - we know you like to try to take the most difficult approach, so I'll just watch along for the ride! Mark |
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DYohn
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Post by DYohn on Mar 25, 2020 19:19:56 GMT -5
LOL - may be the best option... It is, but - we know you like to try to take the most difficult approach, so I'll just watch along for the ride! Mark And then write a seven page thread about why it should have worked and the world is unfair because it doesn’t. |
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Post by boomzilla on Mar 25, 2020 19:43:21 GMT -5
No discreet back channels without processing But if the Oppo gets fixed, it does the processing. |
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KeithL
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Post by KeithL on Mar 25, 2020 20:03:44 GMT -5
I would be remiss if I didn't point something out....
Those movie sound tracks that you want to make sure remain in pristine condition... Have already gone through an awful lot of processing before they were put on that disc... Now, on the one hand, it's not unreasonable to try and make them sound as close as possible to what the sound engineer intended... But, on the other hand, they aren't anywhere near "direct to disc", or even "minimally processed"...
And, if you think that the block diagram of a surround sound DECODER looks nasty... Then you really shouldn't even think about the block diagram of a surround sound ENCODER... And that's AFTER the microphones, preamps, mixers, effects, editing, normalization, and all the normal mastering stuff...
Face it... what really counts is how it all sounds in the end... when it comes out... You really don't want to think too hard about the details and the stops along the way... 
It reminds me of a parable I heard supposedly said by some famous female movie star.... About how you can look really glamorous, but in an artificial sort of way, if you wear enough properly applied makeup... But how it takes even more makeup, applied much more expertly, to look like you aren't wearing any at all... |
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