INTRODUCTION

   We may have always preferred wired over wireless connectivity for various reasons (performance and security being the two most important ones) but the same doesn't apply for cordless telephones since they do offer a level of freedom you don't get from corded ones. Looking back, I got my very first cordless telephone over 2 decades ago (circa 1997 and it was the first model Bosch ever brought in the country) and since then I don't even remember how many have gone through both my house and the lab. The arrival of VoIP last year however complicated things for many (myself included really since I really do like keeping things simple) due to the fact that secondary telephone wall plugs were effectively rendered inoperable (bridging them is the only way to resolve this and that takes quite a bit of time not to mention knowledge which some people just don't have) over night. AVM however has provided a very quick and easily solution for FRITZ!Box owners with their FRITZ!Fon line of DECT telephones and so today with us we have their two latest and top of the line models the C4 and C5.

   Best known for its FRITZ!Box models, AVM is a leading manufacturer of broadband devices for DSL, cable, fiber optic and LTE (4G) in Germany and Europe. Products for WiFi, DECT and powerline ensure intelligent networking at home. AVM distributes its products in over 40 countries. The products are sold through national and international distributors, retailers, and specialist vendors. AVM maintains a variety of partnerships with major European network operators and Internet providers. In 2018, AVM achieved a turnover of 520 million euros and employed 750 people.

   Both the FRITZ!Fon C4 and C5 are cordless telephones designed for use with compatible FRITZ!Box Modem/Routers that feature build-in DECT stations (for example the recently reviewed 7530/7590 models - can connect with up to 6 such cordless phones). These two models follow the DECT-GAP standard, offer HD voice/audio quality (7KHz G.722 codec - encrypted upon delivery), have a range of up to 300 meters outdoors (40 meter indoors) and can be used with both standard and internet (VoIP) lines (SIP-compliant RFC3261). Both models also feature the same 180ppi color LCD screen (240x300p - 262.000 colors), illuminated keypad, 3.5mm port (can be connected to a headset) and 750mAh lithium-ion battery pack (up to 6 days in standby and 10 hours of talk time). Other functions include a very useful DECT-Eco mode for reduced power consumption, motion sensor, loudspeaker for hands-free calls, three party conferences, multiple answering machines, baby monitor, multiple phone books with up to 300 entries, call-diversion, remote control function for local media servers and smart home devices and they even offer the ability to read emails (also reply to emails) and RSS feeds and listen to podcasts and web radio.

SPECIFICATIONS AND FEATURES

PACKAGING AND CONTENTS

Both the FRITZ!Fon C4 and C5 arrived in identical boxes that have the main product features at the front next to a large product picture.

The initial setup steps are printed on the left side of both boxes.

Another product picture is located on the right side.

The features list is located at the rear of the box in 6 different languages.

AVM has placed both telephones inside formed pieces of cardboard as seen above.

Inside both boxes you will find the telephones with their lithium-ion batteries (already mounted inside the C5), charging bases, power adapters, quick guides and product catalogues.

THE FRITZ!FON C4 & C5

In terms of size the C4 (145x48x18mm) is just a tad shorter but also slightly thicker compared to the C5 (150x48x15).

Both the C4 and C5 have 2.4 inch color LCD screens (180ppi/240x300p/262.000 colors).

Their illuminated keypads are also very similar with the buttons of the C4 extending outside of the housing (the C5 keypad does not).

The C5 also has the 3.5mm port at the top whereas the C4 just has an opening from where you can remove the rear cover.

Both models feature loudspeakers located at the rear.

On the right side the C5 has volume control buttons while the C4 has the 3.5mm port (the C4 lacks dedicated volume control buttons).

AVM used the same 750mAh rechargeable lithium-ion battery pack for both telephones.

The charging base of the C5 may look far more elegant than that of the C4 but we found the latter easier to place the telephone in.

USING THE FRITZ!FON C4 & C5

Connecting either the C4 or C5 to your compatible FRITZ!Box modem/router is very easy, just press and hold the DECT button at the top of the modem/router until the screen of the telephone changes to the language selection.

Once you select your preferred language the telephone will download the required translation files (that may take a while).

The default starting screen shows the time and date, handset number (up to 6 can be connected), number of new missed calls and number of new messages.

As you can see from the above pictures both the C4 and C5 have the same number of available functions so you can read and reply to emails, check RSS feeds, listen to podcasts and web-radio, set alarms, enable call-diversion, use the baby monitor function (you set a destination number and you can hear and speak from the destination phone), use a timer, use the nightlight function (the screen stays illuminated), access local media servers remotely, enable/disable WiFi (much faster than accessing the FRITZ!Box web GUI or the smartphone app), use live image (you can check live pictures from a IP camera - not password protected) and check the FRITZ!Box OS version.

Of course you can also set the volume levels, change the ring tone, adjust screen brightness, enable/disable power save mode (screen stays off both off and on the charging base), choose the preferred start screen from 7 available options, enable/disable the large print feature (mostly for older people but we also liked it), make anonymous calls, register/unregister the telephone with FRITZ!Box and of course you can also check the installed software version.

You can access everything related to these cordless telephones from the DECT tab in your FRITZ!Box. From here you can see all of the registered phones, set internal numbers, enable/disable the DECT function, set a PIN (for when registering a phone - safety function), set the DECT field strength and DECT eco features (there's also a very useful daily schedule you can use), permit secure only connections (or not), enable access protection for various functions (via separate PIN), check details and stats for each of the telephones and configure the various web services.

CONCLUSION

   As you may have noticed from the previous page we currently use 3 FRITZ!Fon models in the lab (two C5 and one C4) and for many good reasons the most important of which are without doubt the very easy pairing with our FRITZ!Box 7590 and their available features. Build quality is also very good (although not the best we’ve seen from all the cordless telephones we’ve used) and so is audio quality (crystal clear compared to most cordless we’ve had in the lab). Volume levels are also very good (as a matter of fact we hardly ever used them at full volume) and so is signal quality. Of course the 40 meters reported by AVM indoors don’t seem to be very accurate since with just 3 concrete walls and a distance of just 20 meters between the C4/C5 and the FRITZ!Box 7590 we had just 1 signal strength antenna out of the 5 (our Panasonic cordless phones with their base located right next to the FRITZ!Box 7590 have slightly better signal range). As for the rest of their features they all worked fine (turning WiFi on and off is especially convenient - we would like to see more start screens however) which is also why we’ll be using them in the lab from now on.

   With a price tag set at just 53.40Euros for the FRITZ!Fon C4 (Amazon.de) and 54.63Euros for the FRITZ!Fon C5 (Amazon.de) these two cordless telephones are a must for people with compatible FRITZ!Box modem/routers. True there are many cordless phones in the market that cost a lot less but none offer the number of features these two do and on top of that you can connect/register up to 6 of those with your FRITZ!Box. Their only drawback is however also one of their most convenient features (the fact that you need a compatible FRITZ!Box modem/router) but that’s not something wrong since AVM does have to cater to their consumer base. Overall both the FRITZ!Fon C4 an C5 are identical with design as their most noticeable difference and since both work as advertised they are definitely worth our Golden Award.

PROS

- Good Build Quality
- Crystal Clear Audio
- (180ppi/240x300p/262.000 colors)
- Volume Levels
- Available Software Features
- Good Signal Strength (300 Meters Outdoors / 40 Meters Indoors)
- Battery Life (Up To 6 Days Standby And Up To 10 Hours Talk Time)
- 3.5mm Port (Hands Free Calls)
- Easy To Pair With Compatible FRITZ!Box Modem/Routers

CONS

- Only Compatible With DECT FRITZ!Box Modem/Routers