LONDON, England - Mercedes is preparing to show off a louder engine note during the Spanish grand prix weekend.Earlier in May, team chief Toto Wolff revealed that one proposed solution to the turbo V6 sound 'problem' is a sort of "megaphone" addition to the exhaust.Along with Ferrari and Renault, F1's three engine makers have been considering how to spice up the sound of F1 2014, after some spectators and promoters were shocked at the difference compared to the screaming V8s of 2013."The solutions range from very complex solutions within the exhaust system down to a simple megaphone at the back," Wolff is quoted by Kolner Express newspaper."The 'megaphone' is a parallel exhaust that simply opens up at the end, with all the problems that brings with it," the Austrian added.LOOMING CONCERNSInsiders say Wolff is concerned that the solution will interrupt the thermal and aerodynamic integration between the 'power unit' and the current exhaust layout.Nonetheless, he said that sound solutions will be tried on the W05 car at the post-race Barcelona test next week.But Germany's Bild newspaper claims that Mercedes' plan is actually to test the 'megaphone' exhaust during free practice for the 2014 Spanish GP on Friday.F1 correspondent Lennart Wermke said: "Bild's information is that the solution will be testing in the morning. Whether it is also used in the race is still open."Whether Mercedes can afford to be tinkering with the volume of the engine during the race weekend depends on the challenge posed by improving rivals Red Bull and Ferrari."Barcelona is incredibly important," agrees team chairman Niki Lauda. "It is a key race," he is quoted by Osterreich."Who is good there will be good over the next three or four races as well," Lauda explained."Barcelona is an important measure; even more important than usual because this year the car and engine are being developed more."If we dominant there (in Spain) too, it looks very, very good for us," admitted Lauda.Stay with Wheels24 for the 2014 Spanish GP this weekend.