http://www.usspeaker.com/beyma 10MI100-1.htm

However, I am bit confused about how to determine the optimal throat size for this application.

Often the rule of thumb is to use a compression ratio between 2:1 and 3:1, which with the Beyma driver SD=380 cm2 leads to a throat size somewhere between 190 cm2 and app. 127 cm2. This, however, correponds badly with the throat sizes optained if I use the formula from Melhuish.org horn website where the throat size for given driver can be calculated with the fomula:

St= [2 x Pi x Fs x Qt x Vas]/c which lead to a throat size = 81 cm2 for the Beyma driver.

And if I “ask” McBeans excellent HornResp for the optimal throat size given the driver parameters for the 160-600 Hz horn, then the program suggests an even smaller throat size= 57 cm2.

If I understand it correctly then McBeans HornResp calculations is probably optimized for max efficiency, while I go for best home hifi sound quality where a few dB lesser efficiency is less important.

In HornResp I can achive fairly flat responses using quite different throat sizes, but I simply do not know which throat size is the best sounding.

If I want the driver/horn combo to sound as clear and natural as possible in a home environment, then what throat size should I head for with the Beyma driver?

Thanks a lot!

Kind regards

Peter