Horns

[Keith Oliver]

Our 98 Contessa has a pair of horns on the roof.  The seller described them as "wimpy".  
On our trip home, I had cause to give another driver a blast in anger, and I was surprised how little real noise was emitted.  next rest stop, I had Janet exit the coach and I gave her a blast, then we traded places.  We both thought the blast inadequate.
I have ordered a new "Hadley" 29" horn, rated to produce 135 dB of noise.  I plan to put this new horn on the roof, beside one of the Beaver horns.
Q:  is there enough air in the line to tee off another horn?  
Q2: can I get at the line by removing some small bit of the headliner?  If not, can I pull it up from the top?
Q3: Can I get replacement "Beavers" for the horn covers?
Anyone tried improving the horns on their coach?
I have also seen a set of 3 plastic trumpet horns, 12",10",8", in Harbour Freight, with its own compressor, so all that is needed is 12v supply.  I may add these as well, but would put them behind the front cap, so out of the weather, but where the noise would still get out.

[Ken Buck]

The real question for me would be, why are they wimpy? It could be as easy as a pinched air line going to the horns. In which case there won't be enough air to blow an additional horn either. If there is moisture or other crud in the line, then that could be causing a problem with the originals and they'll work fine when all is cleaned. You do know that many air horns can be "tuned". If yours are tunable then a simple adjustment may help.

Ken

[George H. Wall]

It also could be a WEAK solanoid switch, as was mine, until I replaced it!!!      Henry

[Keith Oliver]

With a new horn as a benchmark, I should be able to figure this out.  I will pick up the new horn next week, get it to the Coach the week after, and some time in the next 2 months, get it installed, after which I will report on success or failure.

[Keith Oliver]

Time to report in.  Side by side, the new Hadley 29" horn has a bell that is roughly twice the size of the original FIAMM 29" horn.  Blasting each through my external air compressor, the Hadley is noticeably louder.  IIRC, it takes a minimum of 3 dB difference before the human ear can detect any difference, and that also equates to roughly twice the volume.  Once installed, a blast confirms the improvement.  Now I need to get a 26" to match.  I decided just to replace the originals, then the old horns will go to my boat, where I have always had a horn deficiency.
Another difference, the new horn is chrome plated brass, and the old ones are Stainless steel.  Don't know if the choice of material contributes to the difference, but back in highschool, the material used for trumpets was always an issue, brass being the consensus as the right choice.
Installation wasn't an issue.  The old horn was screwed to the roof, the air line had 2" of slack, so could be manipulated to get the attachment to work.  The forward support from the old horn was adaptable for the new one, so I didn't have to break through the huge lump of caulking some PO had wasted on it.
I only had to fill one screw hole, re-using the other 2.