Poll: Do you use "pure direct" on AVRs for 2-channel music? - Page 2 - AVS Forum | Home Theater Discussions And Reviews
View Poll Results: For 2-channel music on an AVR, do you use “pure direct” mode or DSP mode?
For 2-channel music, I use “pure direct” mode all the time 23 29.11%
For 2-channel music, I use DSP mode all the time 39 49.37%
For 2-channel music, I use both, but use “pure direct” most of the time 6 7.59%
For 2-channel music, I use both, but use DSP most of the time 3 3.80%
For 2-channel music, I use DSP and “pure direct” about equally 8 10.13%
Voters: 79. You may not vote on this poll

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post #31 of 116 Old 01-11-2020, 11:19 AM
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Yes in Straight mode there is indeed DSP going.

I like Yamaha but boy do they make it all confusing [may be a Japanese to English related problem]. For instance, they have the nerve to call one of their many reverb/echo surround modes "Standard". Zillions of people will select that thinking they are in hearing unadulterated, standard stereo, Dolby 5.1, etc.. WRONG.

I remember at one of my training seminars they were telling us about their surround modes and how they design them. Impressively they aren't guessing what the echos/reverberation patterns are of say "Hall in Munich", they actually went there and measured them! No other AVR brand does that (although some may buy the information to design their circuits). Anyways they were telling us about it all and then explained they decided to call it all "DSP", digital sound-field processing. DOH! That name's been taken so you are again just causing confusion, Yamaha! It means Digital signal processing to the rest of the world!
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post #32 of 116 Old 01-11-2020, 11:38 AM - Thread Starter
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Quote:
Originally Posted by m. zillch View Post
Yes in Straight mode there is indeed DSP going.

I like Yamaha but boy do they make it all confusing [may be a Japanese to English related problem]. For instance, they have the nerve to call one of their many reverb/echo surround modes "Standard". Zillions of people will select that thinking they are in hearing unadulterated, standard stereo, Dolby 5.1, etc. WRONG.

I remember at one of my training seminars they were telling us about their surround modes and how they design them. Impressively they aren't guessing what the echos/reverberation patterns are of say "Hall in Munich", they actually went there and measured them! No other AVR brand does that (although some may buy the information to design their circuits). Anyways they were telling us about it all and then explained they decided to call it all "DSP", digital sound-field processing. DOH! That name's been taken so you are again just causing confusion, Yamaha! It means Digital signal processing to the rest of the world!

I gave my mom a Yamaha 5.1 receiver at least 15 years ago and I'll be damned if I can figure out how to change FM stations. Tune up and tune down changes the FM stations presets, but will not tune it to a new station. From day 1 I had problems tuning it, but somehow manged to set the presets 15ish years ago. Those presets are still there (some of those radio stations are not though ). I'm pretty sure I looked at the manual back then. I'll have to look again next time I'm there. There's probably a mode button to switch between frequency and preset tuning, but I couldn't find it. I do find general operation of that Yamaha pretty confusing relative to everything else, and it's from back in the day when they were simple.
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post #33 of 116 Old 01-11-2020, 11:58 AM
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There's probably a mode button to switch between frequency and preset tuning, but I couldn't find it.
On some brands you are dead in the water for some features if you don't have the remote on hand and I suppose others where you are dead in the water if you don't have access to the front panel buttons.

Also sometimes there's a feature you can only set in an on-screen menu so if you have no TV in that room to look at . . .
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post #34 of 116 Old 01-11-2020, 12:14 PM - Thread Starter
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Originally Posted by m. zillch View Post
On some brands you are dead in the water for some features if you don't have the remote on hand and I suppose others where you are dead in the water if you don't have access to the front panel buttons.

Also sometimes there's a feature you can only set in an on-screen menu so if you have no TV in that room to look at . . .

I still have the original remote and the Harmony One I set up for her 15 years ago, but there is no joy in Mudville in finding the magic button. I've looked on the front panel as well, with a flashlight and reading glasses due to the dim tiny gold text on black background, and can't find it. No OSD -- this was pre-HDMI (supports component, but video is not routed through it, and I suspect it doesn't have OSD but not certain). I'm sure it's operator error on my part, possibly cured by RTFM, but I'm agreeing with you that there are areas where Yamaha is definitely not intuitive. The Harmony One activities I set up fifteen years ago still work flawlessly -- hit "listen to iPod" and it cues up the old 160Gb iPod on the dock and I can control the iPod menus with the Harmony. Hit FM or VHS or DVD or Cable on the Harmony and it all just works. It's a bit like stepping into a time machine.

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post #35 of 116 Old 01-11-2020, 09:00 PM
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I probably should been more clear about "DSP mode" -- what I meant by "DSP" was leaving the room eq/time delays/level adjustments to optimize the sound enabled (basically all the stuff settings you get with Audyssey or REW). I wasn't referring to Hall/Stadium/Jazz club type modes -- just listening in 2-channel mode with DSP on or off (pure direct).

I'm guessing your "straight" mode is like "direct" mode (digitizing but no digital effects applied). For the poll, I think straight mode aligns with pure direct because (if I'm interpreting straight mode correctly) it's bypassing the room/speaker optimization/eq. I did think about having a "direct" option in addition to "pure direct", but there would have been too many poll options. If I had the chance to do it again, I would have said "direct or pure direct" versus DSP.
Every manufacturer has their quirk. Yamaha 's straight mode decodes the number of input channels to output channels. It's got nothing to do with DSP. I only use DSP for bass management when listening to music shen I want to engage the sub. .

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post #36 of 116 Old 01-11-2020, 10:08 PM
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When I used a receiver I used direct mode. I'm currently using an analog preamp.

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post #37 of 116 Old 01-12-2020, 06:42 AM
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I have been trying to find my own answer to this question for the past few months.
I have a Yamaha RX-780, with the mains (Focal) powered through a Parasound power amp.
The Pure Direct mode, when listening to vinyls, produces the best soundstage, free of artifacts. On the other hand it defeats the sub, and my speakers (which I love) aren't necessarily superstars in the bass area.
The compromise I found is to listen in "Straight" mode setting the YPAO equalization on "Through". This way I can take advantage of the AVR's bass management without most of the processing. I'm sure there's still some processing going on, but doesn't bother me as much as the lack of bass in Pure Direct.

Having said that, the next step is to add a stereo preamplifier with HT bypass, so that my turntable stays completely out of the processing path, but still can use the sub.
I bought a Parasound 2100 on eBay, but had to return it as one of the channels was busted. Still on the hunt for one at a reasonable price.
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post #38 of 116 Old 01-12-2020, 10:14 AM
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Quote:
Originally Posted by renpar61 View Post
The Pure Direct mode, when listening to vinyls, produces the best soundstage, free of artifacts. On the other hand it defeats the sub, and my speakers (which I love) aren't necessarily superstars in the bass area. The compromise I found is to listen in "Straight" mode setting the YPAO equalization on "Through". This way I can take advantage of the AVR's bass management without most of the processing. I'm sure there's still some processing going on, but doesn't bother me as much as the lack of bass in Pure Direct.
So in the end you do not use Pure Direct mode but have elected to turn off your auto EQ. Your incoming vinyl analog sound is still being digitized however. This strategy makes complete sense to me and I use it often on my Yamaha as well.
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post #39 of 116 Old 01-12-2020, 12:18 PM
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I voted 50/50 but likely don’t use direct quite as much, primarily because when listening in this extra room I tend to play some multi-channel SACD’s and DVD-Audio’s.

With my Denon AVR-4250CI the Direct Listening modes are; Direct/DSD Direct and Pure Direct. The manual is vague but I always assumed Direct mode disabled all audio processing including bass management. My mains then run full range and the two subs connected to the sub-woofer outs are no longer active. My mains don’t handle under 70 Hz and need a sub. Possibly disabling the sub is only the case with Pure direct? Also an option to configure LFE+Main in some modes but that introduces other problems.

I have some extra equipment I am hooking up and plan on using an Oppo HA-1 in Theater by-pass mode, put a 10B Sub crossover in the chain, add a subwoofer and external amps to run the mains and third sub, and now be able to listen to two channel music full range as another option. Figured I might as well find use for equipment that was just sitting around.
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post #40 of 116 Old 01-13-2020, 10:31 AM - Thread Starter
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REL has an interesting connection methodology for making the sub active in "pure direct" as well as supplementing the mains in "theater" usage. Their suggestion is to connect their subs sumultaneously using both LFE and "speaker-level" inputs (from the left/right mains). Their sub sums both signals. This means that, at least theoretically, the sub performs better in theater mode because the sub is now helping reproduce the left/right speaker bass in addition to LFE (it's necessary to set the mains to "large/full range" for that to work). And the sub will work in "pure direct" because it is driven by the speaker-level inputs even though the LFE has no signal. I'm sure many will criticize this approach, but the only downside I see is that, if the sub distance is very far off from the left/right mains, then distance-based time delays between sub and mains won't align perfectly in theater mode. If you have the mains set to something other than large, though, probably that lower left/right bass is already redirected to LFE, so adding the speaker-level input may not be an advantage for theater mode with small mains.

I don't know if this "additive" approach of using both LFE and speaker-level works for other subs. I would tend to think it might -- but consult the manufacturer if you are tempted to try it.


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post #41 of 116 Old 01-13-2020, 10:50 AM
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I'm embarrassed to say I was a REL dealer for some time so I am intimately familiar with their propaganda which neither I nor any other sub manufacturer endorses. They parrot typical audio mythology, including about high fidelity amps having "sonic signatures" [and this is supposedly "beneficial"] and I do not recommend them.

The notion you can properly use both speaker level inputs and RCA is a bad idea for several reasons.

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post #42 of 116 Old 01-13-2020, 11:03 AM
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Fortunately one can ignore all their silly propaganda and hook them up the correct way but you are still stuck with a poor performance sub.
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post #43 of 116 Old 01-13-2020, 12:36 PM - Thread Starter
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Quote:
Originally Posted by m. zillch View Post
I'm embarrassed to say I was a REL dealer for some time so I am intimately familiar with their propaganda which neither I nor any other sub manufacturer endorses. They parrot typical audio mythology, including about amps having "sonic signatures" [and this is supposedly "beneficial"] and I do not recommend them.

The notion you can properly use both speaker level inputs and RCA is a bad idea for several reasons.
Quote:
Originally Posted by m. zillch View Post
Fortunately one can ignore all their silly propaganda and hook them up the correct way but you are still stuck with a poor performance sub.
To be clear, my post is about the connection methodology and is neither about, nor an endorsement of, REL subs. If other subs support simultaneous use of speaker and LFE inputs, then the connection methodology provides a solution to take advantage of subs for 2-channel music in "pure direct" while still retaining the sub for theater. It's a pretty convenient solution for those lamenting the loss of sub in "pure direct". At a minimum, driving the sub with speaker-level inputs does not in any way meaningfully way degrade sub performance.

For strictly 2-channel systems, I personally prefer driving the sub with speaker-level outputs because, in my experience, it sounds more integrated with the mains versus line-level. I know you disagree vehemently, but that's because you only look at one side of the argument (lower distortion from preamp, even though addition of minuscule amp distortion is meaningless vs sub output distortion) and ignore the benefit that the sub and mains see the exact same "amp" signal with speaker-level. Let's not get into that debate here, I just want to point out that there are two sides to the speaker-level/line-level argument (for 2-channel music) and there is certainly no reason to categorically dismiss speaker-level as an option if it solves the "pure direct" bass issue.


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post #44 of 116 Old 01-13-2020, 01:13 PM
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To be clear, my post is about the connection methodology and is neither about, nor an endorsement of, REL subs. If other subs support simultaneous use of speaker and LFE inputs
There are none other than REL, to the best of my knowledge.

Using speaker level inputs means you aren't using bass management. This is less than ideal and it also means you are adding the hum, hiss, distortion, and frequency response error of your main power amp to your subwoofer* needlessly if you also have the traditional, direct RCA connection available on your system. High level inputs are added to provide means for people lacking the better connection method.

Pro subwoofers never use speaker level inputs, commercial cinemas never use speaker level inputs, and consumer subs often stop having speaker level inputs as an option once you've reached a certain price point in their offerings because they assume you are using it with a modern, higher quality gear. Here's a modern, ~$800 SVS sub, for example, which lacks high level ins:
https://www.svsound.com/products/sb-2000-pro

*[although, fingers crossed, hopefully at inaudible levels]

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post #45 of 116 Old 01-13-2020, 01:25 PM
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From a poll about "pure direct" to a subwoofer setup/use discussion?



If you can’t explain it simply, you don’t understand it well enough – Albert Einstein
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post #46 of 116 Old 01-13-2020, 01:50 PM
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Another thing people don't realize is there is no such thing as a sub amp with direct speaker level inputs even though it may appear that way to the consumer. Before people start insisting I'm wrong hear me out. Amps only take low level "line level" signals and boost them to speaker level, measured in watts. If you don't have such a source signal available for your amp you can artificially manufacture one through a device built in to many inexpensive powered subs called an "LOC", line out converter. It takes in speaker level and converts it to line level so the amp can then do its job.

These LOC devices are not perfect and cheapo ones don't even mention their specs. They have errors including hum, hiss, distortion, and frequency response deviations and this is why it is best to bypass them.

The cheap, free variety you get in subs is probably along the lines of this. However better ones with less audio degradation, such as this multi-channel one I bought recently for other (non-subwoofer) applications, cost significantly more yet still aren't perfect.
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post #47 of 116 Old 01-13-2020, 02:59 PM
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I use the "direct" mode on my Onkyo AVR now that I have replaced a set of satellite speakers with small tower speakers. Working within a tight space and budget, I decided to try the Dayton Audio MK442T's. They were very inexpensive and I wanted to see if two 4" drivers in a transmission line design box would actually produce any bass. They tickle me. The drivers are beefy little guys but the box is not exactly bullet proof. Still, playing them in direct mode sounds great and gives the subs a break until movie time or I pop in multi-channel SACD's or DVD-Audio's.
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post #48 of 116 Old 01-13-2020, 03:06 PM - Thread Starter
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Quote:
Originally Posted by m. zillch View Post
There are none other than REL, to the best of my knowledge.
I'm wondering if it will "just work" with other subs. Both the speaker-level inputs and RCA inputs are typically high-impedance, so dual connecting shouldn't affect amp driving it. There is typically no switch on most subs to select between speaker-level and line-level inputs, so the input circuits probably naturally sum signals. Whether or not an individual sub brand/model has any issues receiving inputs at the same time should be confirmed with the manufacturer before trying it.

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Using speaker level inputs means you aren't using bass management.
The topic of this thread is "pure direct", those using "pure" already aren't using bass management. Those toggling between "pure" and "direct" for bass-heavy music like pipe organ or electronic wouldn't need to that.

Quote:
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This is less than ideal and it also means you are adding the hum, hiss, distortion, and frequency response error of your main power amp to your subwoofer* needlessly if you also have the traditional, direct RCA connection available on your system. High level inputs are added to provide means for people lacking the better connection method.

Pro subwoofers never use speaker level inputs, commercial cinemas never use speaker level inputs, and consumer subs often stop having speaker level inputs once you reach a certain price point. Here's an SVS for example:
https://www.svsound.com/products/sb-2000-pro

*[although, fingers crossed, hopefully at inaudible levels]
Pro and cinema are totally different than home systems, and the logistics related to connections are totally different, and the homogeneity of equipment is totally different than at home. Try stuff and tell us which sounds better. Results will always be dependent on the specifics of the equipment you own. That said, the distortion/hum/hiss from speaker-level virtually does not exist on any properly functioning/connected equipment. It could be argued, strongly, that high-level speaker connections are more immune to picking up noise than line-level connections. There two sides to the story. You are presenting a one-sided story by ignoring the advantage that the sub and mains see the exact same signal when speaker-level is used. We know you don't think that is important -- which is fine for your personal opinion -- you can't simply omit it. Like all things, try all alternatives and use what you found works best in your system.
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post #49 of 116 Old 01-13-2020, 03:21 PM - Thread Starter
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Quote:
Originally Posted by Ratman View Post
From a poll about "pure direct" to a subwoofer setup/use discussion?
It is directly relevant because it's potentially a way to have the subs functional in "pure direct" mode instead of leaving the subs idle. As much as I am generally a fan of pure direct, it sucks to lose subs in the process, several have stated that as the downside of pure direct in this thread.

Whether this type of "dual connection" works for most (non-REL) subs, or turns out to be a practical solution, remains to be seen but is worthy of discussion. It is "on topic" to discuss whether dual connections would work with typical subs. It is not "on topic" to debate line-level vs speaker-level sub connections because either connection type will sound phenomenal compared to the alternative of no sub at all (at least for those who want the sub to be operational for 2-channel).
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Whatever works!
Enjoy



If you can’t explain it simply, you don’t understand it well enough – Albert Einstein
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post #51 of 116 Old 01-13-2020, 03:44 PM
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Try stuff and tell us which sounds better.
No thanks. I have an advanced understanding of audio and pyschoacoustics so I understand the physics of why bass management reduces main amp distortion, reduces main speaker distortion, provides a flatter and more easily controlled frequency response, and increases maximum system output hence musical peaks are reproduced more accurately and cleanly. I also understand the futility of sighted, non-level matched testing because science has shown it is highly flawed. The myths McGowan and REL push don't fool me so I'm not inclined to go to the great lengths necessary to design and perform a blind test either, just like I have never tested, nor plan to test, tarot card readings. I'll stick to the advice and training I have received from the likes of every single subwoofer maker other than REL, Dolby Labs, THX, etc.. Their explanation makes sense.

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I don't know if this "additive" approach of using both LFE and speaker-level works for other subs. I would tend to think it might
No other brand can do this mixed approach because you need two level controls* [which as you can see do exist on the REL in the Youtube thumbnail image], but no other brand has that.

* one for high level in and the other for LFE RCA
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I have to use Audyssey because of my room acoustics. Otherwise, there is a huge bass peak centered at 55Hz In the room. Fortunately, Audyssey XT32 sounds excellent to my ear. It has finally allowed me to use my main system for listening to music most of the time.

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post #54 of 116 Old 01-13-2020, 04:25 PM - Thread Starter
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Quote:
Originally Posted by m. zillch View Post
Another thing people don't realize is there is no such thing as a sub amp with direct speaker level inputs even though it may appear that way to the consumer. Before people start insisting I'm wrong hear me out. Amps only take low level "line level" signals and boost them to speaker level, measured in watts. If you don't have such a source signal available for your amp you can artificially manufacture one through a device built in to many inexpensive powered subs called an "LOC", line out converter. It takes in speaker level and converts it to line level so the amp can then do its job.

These LOC devices are not perfect and cheapo ones don't even mention their specs. They have errors including hum, hiss, distortion, and frequency response deviations and this is why it is best to bypass them.

The cheap, free variety you get in subs is probably along the lines of this. However better ones with less audio degradation, such as this multi-channel one I bought recently for other (non-subwoofer) applications, cost significantly more yet still aren't perfect.
All that is needed is 2 resistors per channel to step down the voltage from speaker-level to line-level. No capacitors no inductors -- nothing at all that would color the sound or pick up noise, or add hiss -- it is the dumbest passive circuit possible. It doesn't need "specs" because none are relevant for a circuit that consists only of resisters. It's impossible to screw up or to cheap out on (it's cheap by definition).

Your multi-channel unit has gain controls, triggers, signal summing, auto-sensing, none of which is needed (or wanted) in a step-down circuit within a sub where every operational parameter is fixed. The sub already does summing for line-level left/right line-level inputs, so the speaker step-down would feed into that.
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post #55 of 116 Old 01-13-2020, 04:29 PM - Thread Starter
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No other brand can do this mixed approach because you need two level controls* [which as you can see do exist on the REL in the Youtube thumbnail image], but no other brand has that.

* one for high level in and the other for LFE RCA

Thanks -- I was wondering how they balanced them but didn't notice that in the video.
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post #56 of 116 Old 01-13-2020, 05:00 PM
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All that is needed is 2 resistors per channel to step down the voltage from speaker-level to line-level. No capacitors no inductors -- nothing at all that would color the sound or pick up noise, or add hiss -- it is the dumbest passive circuit possible. It doesn't need "specs" because none are relevant for a circuit that consists only of resisters. It's impossible to screw up or to cheap out on (it's cheap by definition).
That approach may work for low wattage ones like the Kicker I linked to which maxes out at a 50w input level, so fine for a car headunit output but not a home stereo. For the wattages we use at home or in professional scenarios the LOCs become either active [and active means distortion and hiss on inexpensive ones] or they use transformers, and anything not made with Jensen quality level transformers is going to have frequency response anomalies. The lesser brands usually hide this by simply stating "20-20kHz response" but they conveniently omit the tolerance range deviation window of, say, +/- 10dB [well, maybe not quite that bad, but you get the idea], hence audibly flawed.

I used to have a frequency response graph of one of them showing this flaw, taken from a review where it was measured, but I can not currently find it.

Here's a ~$230 passive one I almost bought, by Jensen, showing its nice flat response.
https://www.markertek.com/Attachment...ifications.pdf

You can actually see the two transformers in this clear bodied one made by a slightly better brand than Kicker, Scosche:

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post #57 of 116 Old 01-13-2020, 07:20 PM - Thread Starter
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That approach may work for low wattage ones like the Kicker I linked to which maxes out at a 50w input level, so fine for a car headunit output but not a home stereo. For the wattages we use at home or in professional scenarios the LOCs become either active [and active means distortion and hiss on inexpensive ones] or they use transformers, and anything not made with Jensen quality level transformers is going to have frequency response anomalies. The lesser brands usually hide this by simply stating "20-20kHz response" but they conveniently omit the tolerance range deviation window of, say, +/- 10dB [well, maybe not quite that bad, but you get the idea], hence audibly flawed.

I used to have a frequency response graph of one of them showing this flaw, taken from a review where it was measured, but I can not currently find it.

Here's a ~$230 passive one I almost bought, by Jensen, showing its nice flat response.
https://www.markertek.com/Attachment...ifications.pdf

You can actually see the two transformers in this clear bodied one made by a slightly better brand than Kicker, Scosche:
External converters need to adapt to unknown parameters because they will be used in a very wide variety of applications. Internal circuits are designed specifically for one fixed environment that will never change. It's absurd to suggest that a purpose-built circuit, designed in conjunction with the rest of the subwoofer, can't step down voltage without introducing hiss, distortion, and not be flat (especially considering the extremely limited frequency range that is relevant to to a sub).
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External converters need to adapt to unknown parameters because they will be used in a very wide variety of applications.
The high level inputs on a sub may take in much less than 1 watt on some occasions in a given system, when the music is low or you set your MVL low, yet even 100-200 watts on other occasions when the system is crankin. I'd call that a wide variety.

What receiver(or int. amp/preamp) and sub do you currently use this way, by the way? I forget.

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We are way too far off topic (should have listened to Ratman!). I'll indulge you with one response.

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The high level inputs on a sub may take in much less than 1 watt on some occasions in a given system, when the music is low or you set your MVL low, yet even 100-200 watts on other occasions when the system is crankin. I'd call that a wide variety.
?????? Of course the input will have a wide range of power levels, that's the operational environment. Everything the step-down circuit has to interface with downstream within the sub is fixed and it is all designed to work together. It ludicrous to say that can't be done without distortion, hiss, and wild frequency deviations.

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What receiver(or int. amp/preamp) and sub do you currently use, by the way? I forget.

What difference does it make?

For speaker-level versus line-level, a Krell KAV-300r driving a Sunfire sub in three ways: 1) driving Sunfire with preamp outputs; 2) Krell preamp out to Velodyne SMS-1 parametric EQ to Sunfire; 3) Sunfire driven by speaker-level outputs. Using SMS-1 digital EQ sounded worse, by far, no matter how much tuning I did (and I did a lot). Speaker-level sounded best -- first time the sub sounded like it was fully aligned with the mains.

On the opposite side of the spectrum, I had the same experience with a small JVC executive set -- sub sounded better driving by amp rather than sub preamp out.

.

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post #60 of 116 Old 01-13-2020, 09:45 PM
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What difference does it make?
So I can show you either that the subwoofer company's higher level units don't even have speaker level inputs as an option, like this one.

Or to quote the manufacturer's owners manual or FAQ pages showing they consider the speaker level inputs lesser than the direct, RCA inputs. . . . Which particular Sunfire do you have?
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