Distributed Bass Array in 4-way stereo, with Acourate

[Labdoc]

I have allmost identical setup, and however my Motu 828ES Audio Interface has 10 output channels only 8 of them are driven by volume control (because of 7.1), which I use. And therefor this is the way, how I will try to overcome the problem.



The schema shows 10 channels, but in fact driven by 8 otput channels (splitted)
(some components and data are not up-to-date, because I am permanently rebuilding, changing the setup)

Hi @Mister Cool,
Nice diagram of the room setup. And also of the component layout.
What software do you use to create this?

[Lewinskih01]

maybe I am wrong, but there seems to be a "misunderstanding". I spend a lot of time experimenting with DBA and other Multi-Sub setups (and I am still in progress -> thats my real hobby ) and I believe, that there are two completely different approaches:

1. DBA (Double Bass Array) approach, which is based on "reducing/eliminating" the reflected sound/wave -> the rear subs act as a "active bass trap"
Pros: wider area for hearing position, Cons: works in rectangular room only

And newly i found Uli's VBA -> my next project !!!

2. SFM (Sound Field Management) approach, which is researched, described by Welti / Devantier, Geddes -> based on a sofisticated combination of delays, sound levels and frequency ranges for each sub (see calculation e.g. with Multi-Sub Optimizer
Pros: not limited to rectangular rooms, Cons: complex calculation

Which one do you try to achieve?

If DBA is the case...

Why do you want to use additional MiniDSP? Because of the limited number of output chanels of your soundcard? (only 8?)
Since the subs are allmost Mono, you could try to drive the two front ones from one soundcard output channel e.g. left (having the same level, delay, correction...) and the DBA/rear ones from the other (right) channel (again, both with the same settings). Then you can drive everything by Acourate w/o additional MiniDSP. All you need is just two differen XOs for the left (front subs) and right (rear subs) channel.

I have allmost identical setup, and however my Motu 828ES Audio Interface has 10 output channels only 8 of them are driven by volume control (because of 7.1), which I use. And therefor this is the way, how I will try to overcome the problem.



The schema shows 10 channels, but in fact driven by 8 otput channels (splitted)
(some components and data are not up-to-date, because I am permanently rebuilding, changing the setup)



BTW. I fully agree with Ulis hint to take care about the dips. In my opinion, most peple are to focussed on correcting the peaks (which is "easy" per EQ) but underestimate the importance of eliminating / filling-in the dips (which is much more difficult). The dips lead to "week", bloodless reproduction. I made some experiments with very simple, cheap 12" subwoofers as DBA placed in the bookshelf and the improvement especialy in the area of eliminating dips was amasing!

Upper measurements are with DBA, the bottom ones without



It was one of the bigest improvements of my system to "close the gap" -> to get this missing, but so important, nice, warm, full bass 35-70Hz

Sorry for the delay in my answer!! I didn't get an email notifying you had answered. Unfortunately the images you posted aren't visible neither thru my laptop nor my phone. Might their path expired?

Sorry DBA gets confusing because it's used for Double Bass Array and Distributed Bass Array. I was/am considering a MiniDSP to introduce the sophisticated "combination of delays, sound levels and frequency ranges for each sub" you mentioned for SFM. Even if I had more channels, Acourate works with xo among them and for this to work best the subs need to work on the same range.

Would love to learn more about your experiment with 12" subs in the back set up as DBA, and how it killed the dips.

I recently received a SET amp to use with my tweeters, and can finally do fully active 4-way stereo. I'm cutting new OBs (wife has been very patient with my prototypes in the living room ) and hope to be refining time alignment, etc in the enxt 4 weeks, and will be back at exploring optimization of bass right after that. Very interested in learning about your experience.