They made their comments during the music trade show fair - the largest gathering of its kind, the Frankfurter Allgemeine Zeitung reported on Saturday.
While there have been some company takeovers in the industry and certain niche sectors are seen as profitable, in general competition is tougher and sales are lower, said Detlef Braun, who heads of the trade show.
This year there were 150 fewer exhibitors than in 2012.
The Society of Music Merchants said 2012 sales dropped by 0.5 percent over 2011, which may not sound like a lot, but the trend is lower.
The key to success in the increasingly competitive musical instrument industry is size and specialisation. Medium-sized companies are seen as having a tougher time than smaller, niche producers and larger firms.
The fair is open on Saturday to the public, but organisers are expecting a drop in attendance, as many music instrument enthusiasts do their research these days online and not at trade shows.