Jump to content

How Noisy Inside Cab Of B


Recommended Posts

Hi Guys, I just purchased a CB for use in my B, however when on the road, cannot hear a thing, even with the sqelch lifted. To converse with passengers, literally have to shout.

In fact on long trips I insert the foam plugs in my ears and wear an ANR (active noise reduction) aviation headset. No, that is not the reason I cannot hear the CB :blink:

Some have told me the reason it is noisy inside is because I have the muffler up alongside the drivers (right hand side) rear quarter of the cab.

Comments appreciated.

Rod.

Proud owner of;

1961 Mack B61 prime mover.

1981 International ACCO 1810C DualCab Fire Truck

Link to comment
Share on other sites

I used to run the stock type muffler up the side of my B. Yes, it does seem to add to the drone inside the cab at speed(ya, speed...like it actually goes fast! ). Anyhoooo, I have since put straight pipes up both sides and a small bullet muffler under the cab. The noise is not any worse than before(even with pipe on drivers side now). The real issue is motor noise THRU the firewall. The exhaust note does not really hurt as much. I too use foam plugs on long trips just to take the edge off sometimes. Mostly don't wear anything since I usually only go an hour or so around here. The strange thing is even after adding the drivers side(american side) pipe it did not really make any noise difference in cab. I know the muffler I had did "humm" pretty good in the cab. I can imagine if your ear is right next to it(like in your part of the world). With the straight pipes I still have to stick my head out to hear it?

Hearing the CB is mostly impossible, even with a small speaker mounted on dash(at windshield height, right in center). Usually if the fellow you are listening to has a crappy radio, it's impossible to understand him. If the other fellow has a decent radio it comes clear enough to understand. I find that I usually let off the noise pedal while trying to listen to something important.

I've put 1" carpet insulation under the stock rubber matt with a heavy throw rug on top of all. It helped keep resonance down, but the motor noise through the firewall I think is the real culprit now. I still have the factory isolation pad, but I don't think that was for noise, only heat. The real answer is sound deadener, like Dale put in his truck. I also glued that same 1" insulation to the headliner and back wall to help take the "humm" out of the interior. I think it helped.

Someday I'll keep upgrading mine.....

Until then...................."HUH?.........Wanna repeat that?" LMAO!!!

IMG-20180116-202556-655.jpg

Larry

1959 B61 Liv'n Large......................

Charter member of the "MACK PACK"

 

Link to comment
Share on other sites

I used to run the stock type muffler up the side of my B.  Yes, it does seem to add to the drone inside the cab at speed(ya, speed...like it actually goes fast! ).  Anyhoooo, I have since put straight pipes up both sides and a small bullet muffler under the cab.  The noise is not any worse than before(even with pipe on drivers side now).  The real issue is motor noise THRU the firewall.  The exhaust note does not really hurt as much.  I too use foam plugs on long trips just to take the edge off sometimes.  Mostly don't wear anything since I usually only go an hour or so around here.  The strange thing is even after adding the drivers side(american side) pipe it did not really make any noise difference in cab.  I know the muffler I had did "humm" pretty good in the cab.  I can imagine if your ear is right next to it(like in your part of the world).  With the straight pipes I still have to stick my head out to hear it?

Hearing the CB is mostly impossible, even with a small speaker mounted on dash(at windshield height, right in center).  Usually if the fellow you are listening to has a crappy radio, it's impossible to understand him.  If the other fellow has a decent radio it comes clear enough to understand.  I find that I usually let off the noise pedal while trying to listen to something important.

I've put 1" carpet insulation under the stock rubber matt with a heavy throw rug on top of all.  It helped keep resonance down, but the motor noise through the firewall I think is the real culprit now.  I still have the factory isolation pad, but I don't think that was for noise, only heat.  The real answer is sound deadener, like Dale put in his truck.  I also glued that same 1" insulation to the headliner and back wall to help take the "humm" out of the interior.  I think it helped.

Someday I'll keep upgrading mine.....

Until then...................."HUH?.........Wanna repeat that?"  LMAO!!!

Link to comment
Share on other sites

When I was a kid, ( still am a kid at heart !! ) I spent many hours with Dad in his B-61 and I don't remember it being that noisy. Maybe it was and I just don't remember ?? Our B-75 is not bad without a muffler,but it's turboed. I'm trying to post an old photo of me in the B-61. We'll see if it works. John

Link to comment
Share on other sites

Hi Guys, I just purchased a CB for use in my B, however when on the road, cannot hear a thing, even with the sqelch lifted. To converse with passengers, literally have to shout.

In fact on long trips I insert the foam plugs in my ears and wear an ANR (active noise reduction) aviation headset. No, that is not the reason I cannot hear the CB  :blink:

Some have told me the reason it is noisy inside is because I have the muffler up alongside the drivers (right hand side) rear quarter of the cab.

Comments appreciated.

Rod.

You could try lining the floor and fire wall on the inside with dynamat. They use that stuff in cars with those big thumping radio systems to dampen out road noise. And maybe the pipes being cab mounted will increase noise so making frame supports for the pipes would be a good idea?

-Thad

What America needs is less bull and more Bulldog!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...