  We reconsider the mass spectrum of double sine-Gordon theory where recent
semiclassical results called into question the previously accepted picture. We
use the Truncated Conformal Space Approach (TCSA) to investigate the claims. We
demonstrate that the numerics supports the original results, and strongly
disagrees with those obtained from semiclassical soliton form factor
techniques. Besides the numerical analysis, we also discuss the underlying
theoretical arguments.
