Reliable Reviews

Sony XDR-F1HD
Sony XDR-F1HD Radio Tuner Sony USA www.SonyStyle.com 1-877-865-7669 or Sony store 7 Z\, 6 C\, 2 C\, 2 Z\x lbs List price $100

By David A. Rich

FILTER According to Brian, the Sony has: Adaptive noise reduction that forms a filter that fits the L-R audio spectrum and follows its changes. The filter suppresses noise between and beyond spectral peaks without restricting audio bandwidth. Brian also identified that the Sony has threshold extension, CHIP SETS which suppresses the impulse noise ordinary deThe measured analog performance of the Sony is bettectors generate for weak FM signals. Analog PLL ter than the Sangean HD radio tuners I previously redetectors have some threshold extension, but with viewed in $ensible Sound (Nov./Dec. 07, p. 12). The DSP more sophisticated detectors may offer inSangean uses a TI DSP chip set; the Sony uses a chip creased extension. set from NXP (the old Philips Semiconductor). Of interContinuing from Brians website: To take full advantage of the processing, the XDR-F1HD not switch or abruptly blend to mono the XDR-F1HD is the best tuner doesRF signal levels. The Sony can deliver at low a for analog reception. clean stereo signal with wide channel separation at far weaker signal levels than can any est is the HD functionality achieved in the NXP design other tuner. The only thing remotely comparable is by adding an extra chip to what was called Car DSP a Carver tuner with Asymmetrical Charge Coupled chip. I have long maintained that modern car receivers Detector. perform much better than what you find in a $4000 Take care when comparing an older analog tuner audio video receiver. to these DSP units with low input signal levels. BriI am doing little here but summarizing Brians work. an reports that with a mono input the XDR-F1HD begins to invoke a sliding, first-order, lowpass noise Because the functionality of the NXP and TI chips are filter on L+R signal as the RF level drops below in the DSP code, a service manual will tell you noth26dBf. The filter is similar to the one in the HDTing. Making things even harder is that the datasheets 1X, which begins at 29dBf and whose corner levels for the HD Radio DSP chips are not publicly available. off at 2.9kHz at 3dB. The Sony corner stops falling Brian thus had to do a significant amount of reverse at 3.2kHz. He found the unit was down 13dB at engineering. Making evaluation more complex is the 15kHz with a 16dBf input. fact that not only do the chip set differences change
In his recent online review (www.ham-radio.com/K6sti/xdr-f1hd.htm), Brian Beezley concluded the XDRF1HD is the best tuner for analog reception. Brian is the only reviewer still making measurements of FM tuners. The catalyst for improved performance is the DSP signal processing that replaced the analog IF and MPX sections of the analog tuner. Complete measurements are on Brians website (www.ham-radio.com/ k6sti/x_dr-f1hd.htm) to allow you to compare this tuner to the best analog units made from the 60s to 80s.
performance, but also software code options that the manufacturer selects change performance. Significantly more technical information is on Brians website than appears here.

audioXpress 8/09

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When the signal level is high enough to turn off the sliding filter, the stereo frequency response is flatter for the Sony in comparison to the Sangean. Brians review of the Sangean is found at http:// ham-radio.com/k6sti/hdt-1x.htm. Sonys adaptive noise reduction discussed previously also helps to suppress noise from co-channel interference and multipath distortion at all signal levels compared to the Sangean. RECEPTION The Sony and Sangean units received the same number of stations in HD mode at my home despite the differences in chip sets. Note that both tuners use simple version 1980s style RF sections that require alignment, and if the tuner is not correctly aligned you will not get as many HD stations. Making objective measurements of the tuners HD performance is impossible because no cost-effective HD radio modulator exists. The Sangean HDT-1X has an S/PDIF output that eliminates DAC ADC interface to an AV receiver. However, the digital encoding used in HD radio (96kbits/sec with no secondary channel) may obliterate the sonic difference of a digital connection. The Sangean has carrier-to-noise ratio readout that allows you to best aim your antenna for optimal HD reception in marginal reception areas. Because HD is digital, it is all or nothing. In a marginal area, the tuner may flop back and forth between HD and analog, which is worse than analog alone even with a bit of noise. That is why the Sangean HDT-1X offers forced analog, which is not available on the Sony. The Sangean also has forced mono. Brian has modified the Sony for forced analog by cutting a trace and adding a switch (see his website) if you want the Sony to be able to have both HD and forced analog reception. Onlythetrace cut is required if you want to turn the tuner into an analog only unit. The retrofit is only for the experienced amateur or a reliable repair shop even for the one cut, because it is hard to get inside the unit and the traces are small. Obviously, your warranty is toast after the mod. A cautionary note: The Sony resembles a table radio and becomes rather hot with all the electronics shoehorned into its compact shell. The Sony has ten flimsy buttons on top of the unit, which provide almost all functions. The remote adds only a couple more. The muting is marginal as you scan stations with a small burst of noise as it passes each station. FEATURES The Sangean is a full-sized component and feels more solid. All functionality resident on the front panel is a real luxury, though it requires navigating 21 touch controls. All the extra buttons on the Sangean allow for direct entry of a stations frequency, making it much easier to tune a station than using the scan buttons. Buttons also vary in size and shape on the Sangean. You can see where the $120 difference in price goes. Unfortunately, the Sangeans have a number of bugs that are identified on Brians website. Sangean appears unwilling to clean them all up although several updates were issued (which required the return of the unit). A summary of the problems with the HDT-1 series is found on Brians website. I never found that any of these bugs bothered me, but I did not set any presets or use the AM HD tuner. Brian notes the Sony forgets many user settings if the power goes out for more than a few minutes. Modifications on his website allow the tuner to retain data longer. If you want to achieve a weak analog signal from a station with HD, you may need the Sangean despite its poorer analog performance to prevent the HD flip-flop problems, provided you do not want to perform dangerous surgery on the Sony. The price of the Sony is about $120 less at street prices, however, and that difference might go a long way to putting in an outdoor antenna if you and your neighbors find the structure acceptable. A good antenna could turn flip-floppers into solid HD stations, but there are no guarantees. I, however, have found better indoor FM antennas (Audioprism 8500 and Terk FM Pro) do little to prevent the flip-flop, although they can improve your ability to bring in a weak analog signal over a floppy dipole. The FCC may evaluate increasing the power of the HD signal, but this would increase the noise of adjacent analog stations and may block weaker ones. I would not expect any rule change soon. Deciding between the Sangean HDT-1X and the Sony is arbitrated by your signal conditions and tolerance for a clock-radio type of thing proximate to your $2000 preamp. Despite its looks, the Sony appears to be free of the operational bugs the Sangean units have. If you have HD flip-floppers, want a stock unit, and have no desire to install a better antenna, opt for the Sangean HDT-1X. If you want to get a weak analog signal with no HD interference, the Sony rr must be your choice.