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Mono Midbasses

2.1K views 13 replies 8 participants last post by  glide 1  
#1 ·
Consider a 3 way front stage with woofers in the doors playing from 60 to 200 hz, mids in kicks playing above 200 hz, and tweeters in the dash. The soundstage will be high due to the tweeters, and most of the important tonal clues will come from the mids.

Assuming you are going for stereo sound, how much would the imaging and listening experience suffer by using summed mono midbasses?

The lower you go in frequency, the less directional sound becomes. I think with a crossover point below 200 hz in combination with the fact that most sounds that low are panned center, i.e. kick drum, bass guitar, low end of snare drum. The low end of guitar and panned toms might be an issue.

Taking the low end of those instruments and essentially panning them to the center while keeping their high end in the mids and tweets could keep them directional while reducing the work each woofer has to do by sharing the load.

A possible downfall is a stereo recording when summed electrically could cause comb filtering and phasing that wouldn't have been as noticeable if summed acoustically.

I think there could be some benefit to this, what do you think?


Robby
 
#3 ·
Cant say yet. But im going to try it out before the next week. I just installed larger midbass. But reading past threads tell me it has been done many times before.
Im gonna say ,your concerns are valid. But it's still trial and error.
 
#5 ·
There have been a few threads in the past that talk about this. I believe werewolf had discussed it quite thoroughly in a past thread. If I remember correctly someone was asking about rear mono midbass. But the frequency/localization theory would remain the same no matter were you plan to mount the midbass's. If I understood him correctly that is!
I will see if I can dig up that thread for you.;)
 
#4 ·
What are you trying to achieve? More output?
 
#7 ·
werewolf:

But midbass is localizable. It seems to me that you wouldn't want midbass drivers directly behind you, anymore than you want them directly in front of you ... collapsed width, due to zero ITD from each driver (and time delay can't create an ITD where one doesn't exist to begin with). So I would advocate midbass drivers off to the side (like the famous Buick Grand National), in order to create ITD from each driver. In other words ... not all locations "behind" you are treated equally, anymore than all locations "in front of" you. There's a "circle of confusion" for midbass sources, you know ... respect the midbass circle!
 
#8 ·
I think it was Zuki or Trini- who pointed out most midbass is recorded in mono anyway. As for localization that is a 'touchy' issue. Some have pointed out it is localizable even below 200Hz. The type of distortion may have a factor as well.

I guess the question is -is it mainly tactile. Cmusic brought up an nteresting point in another thread about being 'trained' to listen. But competition vehicles have shown time and time again - that you can get away with stuff that 'experts' would consider bad form- when you are able to confuse or mtigate visual cues. For example putting in tweeter pods with no tweeters- you might be surprised how many people comment on a
high' stage, Kicks- "oh there is 'some' rainbow effect', etc. Personally - the hardest part is to remove any tactile impressions of midbass- which is difficult- but if done - I am pretty sure - we may change our views of localization-especially in a small cabin - like a car.
 
#14 ·
I think it was Zuki or Trini- who pointed out most midbass is recorded in mono anyway. As for localization that is a 'touchy' issue. Some have pointed out it is localizable even below 200Hz. The type of distortion may have a factor as well.

Not sure what they mean here. I'm a recording/mixing engineer by trade and i can tell you that there are a lot of instruments panned hard right or left with frequencies down to 80-100hz region, distorted guitars, low notes of piano, and cellos etc. I would imagine that by summing this to a center point in a car environment, you would loose "placement" of the particular instrument in the sound stage. On the other hand, you could also get more "focus" and less of the combing effect of the mid/lowmid frequencies. I've always had problems getting good 100-250hz focus, would be interesting to try this. Maybe a beefy 8-10" in a sealed enclosure between driver and passenger seats.
 
#13 ·
Its temporary till i decide. For now I'm using the sub-out from the head.
Low-pass still 160 12db. The Alpine h/u can flip polarity. Run stereo or mono.
Trying stereo or mono. I cant tell any difference ,up to 200hz. But then I'm at the limit of the h/u crossover. So i under lap to blend better.

My reason's are ,I'm now running 8in m/b.
So i take pressure off the comps trying to get low in front bass.