The Firm
The Philosophy
Name Coding


To characterize a loudspeaker in its most important abilities, you must call the frequency range, the acoustic output capabilities and the dispersion characteristics. All these fundamentally important properties of some Stoll electro acoustic transducer systems are coded into their type and name. Many Stoll speakers have a name coding which consists of several elements. There is an up to 8-digit alphanumeric coding, then follows a word marking the name.

Let us take an example using the
Stoll CFR 2410 Convertible.

The first alphanumeric part is CFR meaning the following:
C stands for being a member of the Convertible Range by Stoll. A Convertible can be used as a point source radiator or as one element of a line array. FR says Full Range so this transducer system is capable of generating a solid low-end with a lower cut-off of 60 Hz or below.

Now comes the four digit figure where you have to add a
1 on the front and a 0 at the end. This now six digit long number 124100 you partition and you get: 124 100

124dB SPL long term sound pressure level output which says how loud it goes, and 100 degrees nominal horizontal dispersion angle, which tells you what you can cover using it.

So your Stoll speaker is already quite characterized reading the inherent code.

Then follows its name calling: Convertible. We call it so because it is the first Baby of the Convertible range of speakers by Stoll.


C stands for being a member of the Convertible range by Stoll.
A Convertible can be used as a point source radiator or as one element of a line array.

FR Full Range says it can generate a solid low-end down to 60Hz and below.

FT Full Top has to add some Subs if considerable low-end is required, and can be used as monitors

IL Infra Low technology allows extending the magnitude frequency response down to as low as 8Hz. The much better transient and group-delay time results in a sonic improvement that makes you addicted.

SL Subs for the Low-end going down into the 30Hz to 40Hz region, and up to maximum 160Hz. SubLows extend the FR’s to deeper frequencies and can accordingly dosed generate higher low-end output. Their compact appearance in numbers can be used to realize many different desired low-end dispersion characteristics.

XTL or XL eXtend the low-end output power capabilities of some Stoll FR systems or They can be used up in frequency to several hundred Hertz too, to control the dispersion of lower frequencies of a complete system. Extenders can be used to shape the dispersion in cardioid’s patterns also.

Download «Stoll: Name Coding» as Pdf.