A noob's question regarding SimVibe's chassis mode

[St3fan]

Hi all, I've just started thinking about adding bass shakers to my rig. Although I've bookmarked and read through pretty much all posts related to bass shakers here on RD, I still get confused about the requirement of 4 channels in chassis mode.

Like many people who don't have a million dollar budget and are curious about a SimVibe setup, I'm looking at these Dayton Pucks in the hope that I could test it with the chassis setup (2 in the front on my pedals and 2 behind the seat) and feel how good it feels. If I'm happy about the shaking from them I'll keep them, if not I think I could get a larger shaker for the seat, and move 1 of the pucks from the seat to the shifter.

However when I start searching for a amp I get really confused. I have very little knowledge about audio systems, so could someone explain:

I read that it is possible to drive all of these 4 pucks using just 1 4-channel amp. I did some search and found that most of the amps looked like this one with left/right inputs, and outputs for all the channels:
https://www.parts-express.com/ce-labs-av400-a-v-distribution-amp-4-out--180-006

I'm confused that if I'm gonna use an amp like this one, how do I connect it to the sound card? Am I understanding the chassis mode correct that all four channels need to have different sources? Does that mean I need a 4-channel amp that has 2 sets of L/R inputs?

Thanks.

 

[St3fan]

@Mr Latte
If you are interested here are some of my new progress.
Haven't got the rubber isolators yet but I've changed how I mount the seat shaker.

I inserted a small piece of MDF behind this piece of metal.

Then I nailed it from the front, creating 4 mounting points through the holes. The space behind that metal is very small so I did not consider mounting the shaker using this location.

After that I screwed on another small piece of MDF as the mounting base for the shaker. This is because the cylindrical bar above is not at the same height as the metal piece so I need a bit more space.

Then another small piece of MDF was used to mount the ADX.

The vibration is now much easier to perceive than before. I'll do more test and see how they actually feel.

A problem at the moment is that when I sit on it the spring of the seat will contact the MDF board and rattle.

 

[Mr Latte]

Yeah nice little mod, I see that new bar your now mounted looks to be part of the seat sliding mechanism? So it goes directly into the main frame of the seat?

The rubber I linked would be good for the springs rattling.
For now, just stick in some newspaper or magazine to prevent the noise.
Even try a bit of MDF wrapped in some newspaper (under the board the ADX is now on) as this will push the springs making contact but dampened by the newspaper.

Good to see you trying things....

 

[St3fan]

Yeah nice little mod, I see that new bar your now mounted looks to be part of the seat sliding mechanism? So it goes directly into the main frame of the seat?

The rubber I linked would be good for the springs rattling.
For now, just stick in some newspaper or magazine to prevent the noise.
Even try a bit of MDF wrapped in some newspaper (under the board the ADX is now on) as this will push the springs making contact but dampened by the newspaper.

Good to see you trying things....

The ADX is actually mounted on the casing of the cushion foam of the seat, so it is pretty much shaking where my thighs are in contact with. In fact it shakes so hard that when I watch an action movie I have to turn down the volume.

Now the pedals seem to be the weak spot, but should also be not too hard to sort out.
The Dayton seems to have loads of passthrough. I can hear game audio, movie dialogues from it. ADX on the other hand seems to only convey the shaking.

 

[Mr Latte]

The issue you have here is by splitting a single amp over two channels that are not being used in stereo or with identical units. You cant apply say different EQ & Crossover controls to each individual channel. It will likely control both the same. This issue is more of a factor with "Audio Tactile" as it uses full-bandwidth of frequencies.

Judging by your early reports the BST1 isn't that great and you will likely see what I hinted at earlier. Sometimes it's better to get one good unit and then wait a little longer to gradually upgrade or have the budget for a 2nd. In fairness how good should a $30 tactile unit like the BST 1 perform?

Did you not try to compare the BST1 Vs ADX both on the pedals?
Then consider returning it within the 40 days and get a 2nd ADX perhaps?

Amp limitation.
Sigh........ (says to self, now if only they would listen and buy iNuke DSP amps)
Then you could have worked around your current issue and more if needed no problems running the amp in dual mono mode specifically to tune each unit completely separately.

 

[St3fan]

Hi @Mr Latte I just finished installing rubber isolators for the pedals and now the vibrations are much better in the pedals. I did a rough comparison between the 2 models according to your instructions, and below is my super subjective ratings.

I think I'll go ahead and try the SSW software.

10Hz = Nothing from either shaker
20Hz = Nothing from either shaker
30Hz = 9
40Hz = 6 (ADX much stronger than BST1)
50Hz = 7
60Hz = 8
70Hz = 6 (BST1 a lot weaker here)
80Hz = 8
90Hz = 7
100Hz = 10 (can't tell a difference)
110Hz = can't feel from ADX but can feel in BST1
120Hz = can't feel from ADX but can feel in BST1
130Hz = can't feel from ADX but can feel in BST1

I think BST1 performs quite nicely in this test. The issue I mentioned early is mostly that they respond to high frequency signal way too much.

 

[Mr Latte]

Can you confirm your scoring, the idea was to rate 1-5 in that the best feeling frequencies from all those tested would get 5, the worst a 1. Use a 0 if cant feel. It's easier just to score each unit individually with their ratings for each 10Hz range as this gives a much clearer comparison how you found the two compared.

eg:
ADX 40Hz = 5?
BST1 40Hz = 3?
This highlights that on ADX 40Hz is amongst its best felt frequencies but that that BST1 is quite less in performance at this frequency. Saying one is much stronger does not give people clear comparison.


Eg:
ADX 120Hz = 0?
BST1 120Hz = 1?
This highlights that on ADX nothing is felt whilst on BST1 it can just about be felt.

You have a score of 10 (highest score) for 100Hz as the best feeling frequency?
Sorry I'm confused..

 

[St3fan]

@Mr Latte
Sorry I thought it was a 1-10 scale in terms of BST1 vs ADX... I've redone the test and below are the scores. This time I did the tests more slowly and carefully.
BST1
10Hz = 0
20Hz = 0
30Hz = 1
40Hz = 2
50Hz = 4
60Hz = 5
70Hz = 5
80Hz = 4
90Hz = 4
100Hz = 2
110Hz = 2
120Hz = 2
130Hz = 1

ADX
10Hz = 0
20Hz = 0
30Hz = 1
40Hz = 5
50Hz = 5
60Hz = 5
70Hz = 5
80Hz = 3
90Hz = 3
100Hz = 1
110Hz = 1
120Hz = 0
130Hz = 0