Tom, thanks man! I love the look of your system!
back to the sub hookups, I do get the theory of less distortion from not re-amplifying the amplifier's noise, but in practice, things can sometimes shake out differently.
In my opinion, debating RCA or speaker level hookup styles to avoid re-amplifying a noisy stereomour might just be...still ignoring the noisy stereomour. (Or dungeness amp?) who knows?
The reason I mention this is that usually, I notice very little difference between RCA hookups and speaker level hookups in most of my systems. Often, I ever so slightly prefer the speaker level hookups, or RCA's, or am somewhat indifferent. but the discrepancy between the two is usually not huge like you are saying about the RCA hookups in your system. Now, maybe the double outputted Submissive is just that good, and I'll try it out in my own system soon to confirm. But my stereomour on the other hand is dead dog quiet, which is why I am thinking it might be something different than the simple benefit of RCA or speaker level hookups. The "noise" might be the problem, not the amplification.
Generally, our company mantra is "speaker level" for a variety of reasons, practicality included. (Many of our customers are using integrated amps/receivers w/o any rca hookup potential). Practicality is important because we want to spread this gear (and therefore enjoyment of music) to an ever widening audience. And even in an increasing amount of "wireless" gear, wired still sounds arguably better, and is the only practical way of using physically microphonic tube amplifiers...outside of the speaker box! Its all easy to use, sounds great, and lasts a lifetime, and is never obsolete because its whole purpose is being fundamentally purist gear.
But back to the RCA splitting distortion I was discussing earlier: Bottlehead preamps with proper dual RCA outputs like the beepree, foreplay, and your properly modified submissive are a definite and huge step up over the typical rca "y splitters," from radio shack, but you can still sometimes hear a slight effect on the signal from the extra set of cables being hooked up, and other factors like different lengths/types of RCA cables also still seems to matter. In other words, there is probably no free lunch but the differences are minor when RCA level crossovers and such are properly set up
I should also say that our company structures are a little different. This is Bottlehead's forum. And we usually work out the troubleshooting on our products one on one by email or phone before it becomes a multi theoried forum thread. Information and misinformation about all this stuff can quickly become overwhelming for others, especially beginners, to read and perhaps get confused by all the seeming choices/quirks of tube equipment and single drivers. But it was impossible to see that potential complexity before posting so truly no worries.
Basically, Doc, PB, and I are all recommending different solutions to your problem. I don't have a problem with that, but people looking from the outside in, who might just be getting into this stuff, are probably more than a little confused by the jargon and conflicting theories by now.
While we do not "generally" recommend RCA hookups into Dungeness because of equal parts "it does not/should not matter much," assuming optimal health of components upstream, there is nothing expressly wrong with it. If it works it works. But speaker level hookups are often easier for folks to understand in terms of how to physically get the "mess of wires and drivers" to work. expanding this conversation's scope to the rest of the audio industry, everyone has their preferred method. That's part of the richness of this hobby!
So - I am not by any means "anti-RCA" level tone controls, crossovers, volume controls, etc. I am merely presenting them as potential variables to be assessed in terms of individual "component health" in the hollistic system you are troubleshooting.
I'd love to see more audiophile/minimalist/simple RCA line level 40-180hz crossover/biamplification products on the market, for instance. mmmmm... tube bass! But admittably, active crossovered, bi amped, SET tube will most often be for the purists (like us, who are regulars on this forum) who probably already have a few different tube amps around and are looking to put them to good use.
But in the same stroke we want to keep the product's presentation simple for the reason that for beginners, penetrating all the way through this mumbo jumbo audio lingo is tough and most folks just want to know that our speakers sound good, make bass, with Bottlehead gear. And as your data point and my data point, and other pleased folks on this forum confirm, that is the truth!
Thanks,
Clark
