Geddes multiple subwoofer method - 3 subs vice 4


Geddes recommends 3 subs for optimal sound - a different perspective

 

Interesting video depicting Geddes philosophy on using subs. Also, he treats the main speakers as part of the bass solution and does not recommend using high pass filters as this takes away from the total bass capabilities of the entire speaker sub interface system. I am going to experiment this weekend. Also, a higher crossover frequency for the first sub collocated closer to the main speakers is new to me. Recommended above 100 hertz for the first sub and then incrementally lower for the 2nd and 3rd sub in an asymmetric pattern. 
 

I feel like the Geddes approach for sub integration closely resembles what I have been doing for years without even knowing this method. So, my 18” deep bass and 15” mid bass drivers on the field coil speakers become part of the solution instead of being taken out of the equation. That’s what I have been doing and that’s what I thought sounded best to me. Multiple ways to do sub integration but this method is the one that pretty mirrors how I have been doing it for years.

audioquest4life

I am going to dip my toes in a digital solution soon. I got rid of my JL subwoofers (with apologue high-pass) and ordered new subs (JTR RS1). This time around I am going to try the MiniDSP SHD for sub integration. Not sure the MiniDSP will be good enough for a long term solution for me (clean enough? Maybe?) but it will let me try different filters and what not (has its own PEQs, and Dirac too). If I like the solution I will try something more highend as money allows. The SHD is limited to two subs and I think I would like to try 4 at some point


My room is pretty large especially with the back doors open to other rooms. The room is effectively 42’ long and 26’ wide with everything open. So I don’t fight room nodes as much as others. I just like the slam of subs (no speaker can touch it) and want to digitally align them more or less.


I don’t see anyone using JTR stuff for music so it should be interesting (they have a trial period, -shipping). I just picked based on the measurements, impressive extension, overhead, and low group delay. For their measurements they were pretty “cheap”.

Dear @james633 : " I don’t see anyone using JTR stuff for music.."

Well the main reason is that JTR subs are designed for HT in specific and not for MUSIC systems.

In HT THD is not to important and even that the enty level RS1 measured more or less " fine " its THD goes to high but your JL are not way better in that regards and certainly not only in the RS1 price range but with out the " impact " in the low bass that has the RS1.

 

Btw, it looks a lot to the Velodyne 18"/15" that are higher in price but more important is that Velodyne's THD goes at 0.5% thank's that the design checks in real time over 16K times each second the woofer excursions.

In the other side:  " I would like to try 4 at some point.."

Of course you can but at one specific seat position we need only 2 subwoofers and Harman showed 30+ years ago why even that in its study said the optimal are 4 for the " room space " not one and only seat position as with dedicated MUSIC system .

 

R.

Dear friends: For me exist a critical issue to use DSP for the  high-pass filtering and blend the subs to the mains.

The question is for each one of us way of listening MUSIC. I own thousands of LP's and only hundreds of CD and I really don't care about streaming even that today digital in many ways surpass the analog alternative but due that I listen mainly to LPs I can't contaminates the overall analog signal doing it that pass through a digital domain .

Apples can't mix with oranges at least for me. Main difference between analog and digital and where digital outperforms analog is in the bass range but even that I know that I prefer to stay all the way down to analog but as I said: this is me and only an opinion.

 

R.

I have never heard streaming come close to analog. I think that redbook sounds better than streaming. Even heard a difference in file types. Until they get a handle on high def. streaming I am not interested.

Rauliruegas,

A good sub is a good sub, JTR is just ugly (I have a mixed theater room, painted black, so no big deal). Not sure THD matters too much as they are all good and far out pace even the largest of speakers. Integration is most important. At any rate they have a trial period so I will see soon. 
 

Not really looking to debate subs, they all perform well but some data from audioholics. The E112 at 105db-ish /25hz has 25% THD and the JTR is 05% at 105db-ish. The perlisten 215 is 3% at the same volume/hz but 3 times the price. Both JTR and Perlisten are digging deep into infrasonics and should just be cruising at 60hz under 100db. Velodynes are nice subs, I have not heard one in 20 years though.