DEBRA / SWARM DSP?


I’ve been trying to learn about room treatment and Room EQ Wizard (REW). In my research so far, It seems DSP is not a great idea for the main speakers in 2ch system, but it might be a good idea to use DSP for subs. In my DEBRA sub-array, it’s a little different in that I have 2qty SA1000 Dayton amps instead of the standard 1qty SA1000amp for all 4 speakers. I have 1 amp for the left front/rear subs and the other amp for the right front/rear subs. Will this work with the mini DSP? The mini DSP has 2 inputs and 4 outputs. I don’t see how to run the software/ correction/alignment with 2 subs being run off of 1 amp per side. 

BTW, I'm running the speaker level out from my tube amp through 1k and 10k transistors and terminated into 1 rca per side which go into the 2  SA1000 amps...1 input per side 

Any knowledge you may be able to impart would be greatly appreciated.
veerossi
I have the same 2 amps with 4 subs just like that. Plus one more because, millercarbon. You already have a lot of EQ built into your Daytons. If you really want to double down with DSP the simplest is to connect the DSP to each amp. The DSP is equalizing bass response. It doesn't know which or where or how many speakers. It only knows frequency and volume. You could hook all 4 subs to one amp and use it. Same result each time because, same DSP. 

The LOC you built with your 2 resistors is identical to mine. https://systems.audiogon.com/systems/8367 
That red carpet of yours is horrific millercarbon. Terrible

kenjit
1,387 posts02-17-2021 9:59am

That red carpet of yours is horrific millercarbon. Terrible

<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>

It ain’t gonna turn out well K.
As you set in your beanbag chair, spillin’ cheap wine, on the dirt floor.

Can get nasty "Kiddo".

Regards
I just received the following PM from kenjit, quoted below in its entirety and unedited.  

hi

would you like me to come and assess your speakers? free of charge. They will need to be equalized to your ears. I bet you I will be able to find many things wrong with your speakers! who is Deborah?

You are welcome any time. Consider it a standing offer. You and anyone else. In Redmond, WA just two miles east of beautiful Lake Washington, about a half hour north of SEA, which is where you would land. For out of towner's we have a spare room all set up and you are welcome to spend the night. Just PM to make arrangements.  

Your timing is good. Main weakness now is acoustics. Planning on consulting with our local expert, Mike Lavigne. But first-hand impressions and experience, you can never get enough. 

It will be a long trip, but if you come late spring or summer we are real close to some absolutely stunning scenery. Heck, Mike is up so near the pass his back yard will impress anyone not born in Yosemite. That's what the Portland group did last time, pulled a train from my place to his. 

Any time. Let me know.
That is quite a system you got there MC. I hope to someday hear them Moabs. I'm curious to see/hear how they compare to my Tannoys- especially in your system since we share a tube amp and somewhat similar sub setup (except mine doesn't go to "11" with a 5th sub). 

I'm thinking there is no way to run separate DSP to adjust delay time or EQ separately without having to run 1 amp per sub. 
I wish I would have known that LOC setup years ago. I would have been into SET tube amps a lot sooner.

Kenjit: All you need to know is DEBRA likes to go boom boom long time.
You are welcome any time veerossi. Never heard Tannoys so can't say much except Moabs are pretty darn impressive. Especially since mine have been taken apart and treated to some crazy good tweaks that must sadly for the time being remain secret. (Or at least off-line.) Clean, clear, dynamic and detailed without any edge or hardness, and able to play good and LOUD with little power and no strain, they are the perfect speaker for me. Or to paraphrase the Tommy Lee Jones line in No Country For Old Men, "If its not it'll do till the real one gets here."   

What I would like to hear is this same setup with a SET. Bet it would be mesmerizing- even more mesmerizing I mean!   

I came here looking for help before doing that LOC mod. Something I always knew was possible but never knew how until, necessity being the mother of invention, I went looking. https://www.epanorama.net/circuits/speaker_to_line.html

Kind of wondering why you want DSP? Dayton already gives you a lot of range, and with four subs the bass ought to be pretty darn smooth already? Have you tried connecting them series/parallel to hear which you prefer?
I have a miniDSP 2x4HD on my 4 sub array with the same amplifiers (thanks so much Duke!).  As MC states, you'll be limited to one set of DSP settings per amplifier.  Perhaps not ideal, but in the end you're really correcting for 1 listening position, not 4 subwoofers. 

The miniDSP paired with REW and a calibrated microphone (e.g., the umik-1) is really a wonderful tool.  Make the measurements at the listening position and immediately import directly into miniDSP to create the appropriate filter.  *Many* more options and flexibility than the onboard EQ settings on the Dayton, and if you're set up correctly, you can make all the changes directly from your listening position.  I find that invaluable for evaluation accuracy.  So much easier than getting up, moving a tiny knob without feedback, and then sitting back down and trying to figure out how the sound changed.  
Cal, did you find the miniDSP 2x4HD to be useful for making delay adjustments or did you just use for EQ? How do your amp and subs wired?
A. 1 amp for 2 front subs, 1 amp for 2 rear subs?
B. 1 amp for LEFT (front/rear subs), 1 amp for RIGHT (front/rear subs)?
C. Or some other way?

I am wired B

If you have direct access to your pre-amps outputs, you would ideally connect your pre-amp outputs to the minidsp inputs. You would then connect two of the minidsp outputs to your main amp and the other two outputs to the Dayton amps using a “Y” cable. Assuming you need to use both left and right inputs on the Dayton amps.

Another option would be to use a DBX PA2 instead of the minidsp and connect your pre-amp outputs to the DBX inputs, then connect two of the DBX outputs to your main amp, two of the outputs to the left Dayton and the last two outputs to the right Dayton.

A third option would be to connect the pre-amp outputs with “Y” cables to the Daytons inputs and then connects the the Daytons high pass outputs back to your main amp’s inputs. 

All of these connections assume you have pre outputs and inputs of some type.


I have two sets of outputs on my pre-amp. One goes to my main amps, the other to the minidsp. One minidsp output then goes to a dayton with two 8-ohm subs connected in series (front and left). The other does the same, but runs the right and rear subs. 

Inside minidsp 2x4 hd you have the options to combine the stereo inputs into a mono signal, control the crossover cutoff and slope, input up to eight (if I remember correctly) eq adjustments, control volume level (up to +2db), and adjust delay. All of that can be modified independently for each input and output channel. It's a truly amazing piece of equipment.
My only complaint is that the minidsp (and the Dayton amps) have a low input impedance (8 kohms I think) and can be difficult for some preamps to drive.  If you've got a tube preamp with output capacitors, you'll want to be careful they're big enough not to start rolling off the output to the subwoofer system.

Note that using a y-cable will present the same issue. Consider checking with your pre manufacturer to ensure your unit can drive both the sub system and your main amplifiers.

My Don Sachs pre could, but my new dht pre (one single tube of voltage gain) just doesn't have enough current to push both.