Since i mfg the most popular unit of this type I have done a great deal of experminting. in answer to your question the mid barrel works great without a front tuner but we have always gotten slightly better results withthe use of a front tuner. we have also benefited from the use of two mid barrel tuners onthe barrel. If you would like any further information you can call me at 913-649-0201 or cspss@att.net.
I have 6 Harrel Mid barrel tuners on sever different rifles. They do work without a muzzle device and they work very well with a muzzle device. I've used them on several Iron site rifles, where muzzle devices were not allowed, with great success.