OEM Car Stereos better for DX than aftermarket?

[mikerichardson]

My first car was a Chevy Cobalt with the stock GM radio, a standard Delco model, and I remember getting some pretty good DX at night on that radio. One night I got some great DX from New Orleans and I am in Houston. Normally I get DX from the west - Austin and San Antonio and the like. I always figured it was because the Cobalt had a real, legit, screw on permanent antenna mounted next to the trunk. I got the best DX in the upper FM band, and I remember one time measuring the antenna and discovering that it was pretty close to being a "half wavelength" antenna.

I pulled the Delco radio because I wanted an AUX port but I got a lot less DX after that. The aftermarket unit was a Sony which was otherwise decent, still having RDS and everything, and I had SIRIUS hooked up as well. The antenna was the same.

Recently I rented a new Nissan Altima for a week and I noticed right away some great DX from Beaumont and San Antonio. And as far as I could tell, this car had a very short antenna, not even a quarter wave, yet I got some great stuff in this car. Maybe it was just a coincidence and it was a great DX night, but still, the radio was locking into DX stations on just the regular auto scan mode.

I have a '93 Chevy Van I use for work doing computer recycling. I bought it used several years ago and it literally had a Delco AM radio. No FM. This is definitely a 1993 model, and I had to check, but they actually sold this model with AM only radios. I think I had that radio recycled and put in a cheap JVC model since it's just a work van, but I never got any DX on there, even at night, and it has almost the same antenna as the Cobalt did - seems like it would be a quarter wave length antenna on the upper side of the FM band.

Even my parents' Hyundai Santa Fe, which has a crappy window antenna with the thin little lines, seems to get a decent DX now and then, even pulling in one 103.5 Bob FM from Austin one night.

So has anyone else concluded that, at least with car radios, OEM radios seem to do better for DX, compared to those aftermarket ones you get at Best Buy?

 

[rbrucecarter5]

So has anyone else concluded that, at least with car radios, OEM radios seem to do better for DX, compared to those aftermarket ones you get at Best Buy?

I had about the same experience in the 70's - until Pioneer introduced the supertuner. The AM has never been as good as vintage Delcos from the 60's with a large whip. But then modern Delcos are not as good as those vintage Delcos. I've been in many a rent car over the years, and I've ridden in / tested for DX many models of aftermarket car radios. Sometimes - side by side tests with other DX enthusiasts. Many of which ripped out their Sony, Alpine, Kenwood, etc. to put in a Pioneer. I can tell you - Pioneers are the real deal, DX wise. There are some junky cheap Pioneer models, you really need the Supertuner 3D, not the Supertuner 3. But I can tell you if you have a decent antenna on the car, Pioneer will outperform just about anything you can name. Probably everybody on here knows I am a DX fanatic - enough so that I will spend money to try new things. There really isn't anything better. You can get better sounding, trendier name, etc. But when it comes to sensitivity and selectivity where it counts, Pioneer is the only way to go. I don't work for them or anything. I just endorse something that works. I don't know how Pioneer would work with one of those junky shark fin or nub antennas. Probably it would do the best it could, but for serious DX - take the time to put a whip on the car. You can get old CB magnetic mounts if you don't want to drill the fender.

 

[audioguy]

A number of years ago after I bought my Camry, I decided that I wanted a CD player instead of a cassette, so I bought a modestly priced car stereo from Kenwood. After I installed it, I was shocked at how much better the audio sounded on both AM and FM. The improvement was well worth the money spent. In fact, it was so much better that I decided I didn't even need to change the speakers. Although it is not a "DX machine" I would say that its performance has been very decent, and certainly a lot better than many consumer radios that I've used over the years. For me, audio quality is the most important thing, assuming I can receive the station I want. There are times when I would like to be able to switch to a narrow IF, but not many times because I wouldn't want to accept the reduced audio quality that would result.

 

[rbrucecarter5]

A number of years ago after I bought my Camry, I decided that I wanted a CD player instead of a cassette, so I bought a modestly priced car stereo from Kenwood. After I installed it, I was shocked at how much better the audio sounded on both AM and FM. The improvement was well worth the money spent. In fact, it was so much better that I decided I didn't even need to change the speakers. Although it is not a "DX machine" I would say that its performance has been very decent, and certainly a lot better than many consumer radios that I've used over the years. For me, audio quality is the most important thing, assuming I can receive the station I want. There are times when I would like to be able to switch to a narrow IF, but not many times because I wouldn't want to accept the reduced audio quality that would result.

The OEM Toyota with AM stereo was a great radio - as OEM radios go. I still swapped it out for a Pioneer because I was in Jackson, Michigan at the time and wanted to get 93.9 out of Windsor, which was first adjacent to a Lansing 94.1. It also helped with an 88.7 out of Windsor. That said - the AM section of the OEM Toyota was really good - all the Chicago 50 kW's were strong as locals in Jackson, MI. Too bad that was also the era when the music died on WLS, so the AM stereo section was basically wasted at that point. I sure wish I had saved that old Toyota OEM AM stereo - it was a darn good AM radio (although FM was so-so). But - who knows what a narrow ceramic filter mod would have done to improve it?

There is a misconception that changing to narrow ceramic filters in an FM radio will make the audio worse. That is not true. The bandwidth of an analog FM station is determined by the deviation - which has nothing to do with audio response. Well, only loosely. The deviation of an FM station is +/-75 kHz, including mono, stereo, SCA, RDS, blind reading, etc. If you change to 150 kHz ceramic filters, you still encompass the entire +/- 75 kHz deviation so all those services will still work. The key is to match the filters. The only reason why most radios come stock with 280 kHz filters is that they don't have to be matched. They can just plunk them in there with no testing. And that makes for poor selectivity, and because of the gain / bandwidth ratio it also hurts sensitivity. Badly. Even the older Pioneer Supertuners came stock with two 230 kHz filters and one 180 kHz filters - they could really be souped up by changing to 150 kHz. But the newer Supertuner 3D has adaptive IF which is even better. The smallest bin is 60 kHz wide, which gives super sensitivity on extremely weak stations which would only be receivable in mono anyway.

 

[purpledevil]

In my experience, Mike, I find the OEM in my wife's Neon much better for DX than the after market Kenwood in my Ram's dash. This holds true for both bands. Of course, no radio I own brings in signals like my Fisher receiver I bought about 20 years ago. The carousel has long since broke, and it'll eat any cassette deck you put in it, but it will pull in signals from Beaumont with a simple pair of rabbit ears, like they belong here.

 

[audioguy]

My Toyota OEM radio did not have AM stereo. It was strictly mono, and the audio amp must have had some sort of design problem with high IMD. It sounded like mud on everything-- AM, FM, and the tape player. It wasn't something you could easily put your finger on, but it caused listening fatigue. When I put in the Kenwood, not only did the frequency response open up, but everything was so much cleaner. It was a revelation!

The Kenwood FM section has 4 matched 230 kHz filters. It works reasonably well. It will separate stations 200 kHz apart if there is not a large discrepancy in signal levels. I modified the blend circuit so it stays in full stereo mode down almost to the noise level. The radio will lock in stereo at the noise level; you can see the indicator come on if there is any signal available at all.

 

[spunker88]

Part of your issue sounds like the small antennas that they put on new cars. Also Delco car radios back in the day were really good tuners.

I now have a 2012 model Pioneer aftermarket radio that I installed in my car and its one of the best car tuners out there, thanks to the Supertuner 3D DSP chip. I was down near Syracuse the other morning and it was pulling in 95.9 Virgin radio from Montreal with some tropo. A 200 mile catch on a channel with a strong local on 95.7 (thankfully no HD). My factory radio would have just had adjacent interference.

Some people have reported bad reception on after market radios when they didn't connect the "power antenna" wire to their aftermarket stereo. I hooked it to mine, figured worse case its unused and dead ends somewhere. This wire provides 12v when the radio is on, its used on cars with a motorized retractile antenna, but is also used to turn on antenna amplifiers in some cars. I'm not sure why car antennas need amplifiers given the short distance, but this video shows the effect of the power antenna wire:
https://www.youtube.com/watch?v=HFFHmaAHEv4

 

[crainbebo]

I like stock radios. We rented a 2010 Toyota Corolla from Hertz for a trip to Yakima (in Central WA). I had loads of stuff with that radio. KUMA 92.1 Pilot Rock, OR, 110 miles away and weak, was heard with zero interference from the big local KDNA 91.9. Ditto KBLD 91.7 Kennewick.

I would love to try a Pioneer Supertuner 3D someday however.

-crainbebo

 

[spunker88]

I like stock radios. We rented a 2010 Toyota Corolla from Hertz for a trip to Yakima (in Central WA). I had loads of stuff with that radio. KUMA 92.1 Pilot Rock, OR, 110 miles away and weak, was heard with zero interference from the big local KDNA 91.9. Ditto KBLD 91.7 Kennewick.

I would love to try a Pioneer Supertuner 3D someday however.

-crainbebo

Newer Toyota and possibly other brands have started using DSP chips in their radios. My parents have a 2010 Rav4 and I can tell its some DSP chip inside. I'm impressed with how noise free the AM section stays while the engine is running. Just wish they had RDS on it. I imagine since there is no RDS in Japan its not very popular on Toyotas and other Japanese brands.

 

[crainbebo]

Surprisingly, I thought that the little plastic antennas were horrible for AM. When I got that Corolla for the Yakima trip, at the rental dealer (Hertz in Kirkland WA) was a 120 mile, clear reception of CHMB 1320 Vancouver in the day. I was surprised.

-crainbebo

 

[DanielBoone]

Pioneer Supertuners are the best!!! I think the ones prior to 2008 are best.

 

[KenoGuy]

The factory stereo in my 2001 PT Cruiser has an excellent radio. It's the Premium Sound unit with CD, cassette, 3-band EQ, and AM Stereo. The AM has a pretty wide filter and sounds excellent, but the tradeoff is IBOC for 2 channels up and down from a strong station. It is VERY sensitive and gets virtually no vehicle-generated noise. The FM section is also very good.

This stereo has actually affected my decision to keep the car around a little longer.

 

[briankay]

I have nearly always found the factory OEM head units had better reception than any of the Pioneer Supertuner units I bought over the years in several different cars (Supertuner II, Supertuner III, Supertuner IIID, the Pioneers would always blend to mono far too easily, and I was always hoping the next gen Pioneer would be better. I always tried them with and without the car's antenna pre-amp energized, and still the Pioneers would fade or blend to mono so quickly. I now have a 2010 Prius with the basic factory radio, with 8" antenna, and it's keeps a wide stereo image out to 50 miles from the Chicago TX sticks, which are all about 6 kW transmitters. Pioneer blends to mono at about 30 miles out. I guess when people talk about the good Pioneer reception, they're talking about the mono reception I guess. Even though I always heard by the so called experts that reception is all about the antenna, 31" whip, center roof mounted (which I went to the effort of doing in my 3 previous cars), I am now coming to the conclusion, it's more to do with pre-amp and tuner's FM head-unit quality, processing and their matching, than having a good old 31" whip antenna. Much of the info on the net on what tuners maintain a strong stable FM stereo image is either not available or contradictory. The Blaupunkt comes up a lot, so I'm beginning to believe the sensitivity and selectivity figures are not really a big help in finding the best car FM tuner. Since 2007 my experience with FM HD radio is similar, it's hard to find info on what units hold the digital signal best 30+ miles away from the sticks. Sometimes one finds a gem tuner when renting a car and that seems to be the only good way I can happen on a good car FM tuner, as going by the few user reviews on the net yields more often than not, little light on the subject.

Does anyone know who does the best HD Radio car tuner head units, both on the OEM side and the aftermarket side? Some of the criteria: 1.) holding the digital signal, 2.) how good it blends to analog, 3.) how good the stereo analog is when the HD is lost, and 4.) how good the AM is both (HD and analog)?

 

[1L6E6VHF]

I haven't had an aftermarket car radio in about 15 years, but I do know one thing for sure about the aftermarket radios I had those days - their FM tuners were just awful when it came to front-end overload.

The OEM radio in my 2007 Toyota Prius is quirky. On AM, its sensitivity is nothing short of fantastic, and its selectivity is very good (audio quality is poor, however - as I believe the radio has a 5kHz LPF to take out IBOC noise). On FM, the radio is very sensitive as well, when parked - BUT, when I'm actually driving, the electronics that charge the battery and then make high voltage AC power from the battery power while accelerating produce enough interference to limit FM listening to local signals. The international broadcast and amateur bands, even 2 meters, just get completely whacked when the car is running, especially on breaking. The CD player also has trouble playing discs other CD players have no problem with, especially if it is cold.

 

[N4GBK]

This thread is about FM DX reception, and that can mean different things to different people. One radio may be perceived by the listener to be better for regular listening to a fringe station during a commute with a sports or talk program while another may be better with a music station. As a DXer, I am interested in getting as many different stations and I am not necessarily interested in the audio quality or how well it blends in and out of stereo when I am in the DX mode. I agree with rbrucecarter5 about the sensitivity and selectivity of the Pioneer Supertuner IIID (STIIID).
If you are trying to get as many different stations, then the STIIID can pull in the weak ones in the adjacent channels next to the strong signals. Other radios may be able to do a better job of blending from stereo to mono but as a DXer, that is not a concern to me. (The STIIID has an option in the programming menu that may help with your blend problem.)
Also, automakers are doing a great job with using the amplified shark blade and similar small antennas on their vehicles. Getting these antennas to work properly with aftermarket radios can be a problem. Check with Crutchfield or other car audio specialists for assistance.
BTW, I also enjoy the local music stations on my STIIID as it sounds great on a good signal. If there are any imperfections in the audio, they are covered up by the road noise when zipping down the road.
(AM reception with the STIIID is average, those old Delco AM only radios were sweet!).
Happy Thanksgiving y’all! -Bill

 

[rbrucecarter5]

Two years ago, I would have agreed with the assessment of Pioneer Supertuner 3D AM reception. But I replaced my old Pioneer with a newer, HD model, and was very pleasantly surprised by a new, super hot AM section. I guess they souped it way up to try to get AM HD working, and all I can say is - it isn't 60's Delco with a 60 inch whip AM sensitive, but it comes closer than anything I have analyzed yet.

OEM car radios - Delco now uses two FM ceramic filters, replacing them with 150 or 110 kHz wide filters gives them a fair amount of adjacent channel reception, and a big sensitivity boost.

As far as whips go - almost any car radio can be boosted on AM using some tricks borrowed from ham radio. You aren't going to get an electrically efficient antenna in even 60 inch whips, but a bottom loaded coil with the longest whip you can get will give you an electrical length close to 1/20th the wavelength of AM - which is the threshold where antennas begin to have efficiency. I've heard of 600 miles plus AM reception using this technique. People in the wide open spaces of the West use this trick, although some people in the midwest are using it to get New York and other stations they are interested in.

As far as FM - I don't know what they are doing in the shark fins and stubs. They seem to be taking inadequate antennas and amplifying the heck out of them in order to get some sensitivity. Whatever - I have NEVER seen a car with a shark fin, nub, or antenna in the rear window do as well as a whip. I did car shopping at Car Max with my daughter a couple of years back, and sneaked in a quick check for a couple of benchmark stations 100 to 150 miles away, and a local translator my daughter was interested in that was 25 miles away and definitely very deep fringe. We were in a lot of makes and models - she was picky. GM, Ford, Chrysler, Toyota, etc. About half of them with the top of the line audio systems from Bose, etc. They ALL had those integrated radio / GPS / backup camera systems that would make OEM really hard. Local stations all came in, some near rim shots as well. But the really deep fringe DX stuff - not a single car had them. Our 7 year old van, with an OEM Delco and 31 in ch whip - not anywhere close to their top of the line system - all got my 150 mile away benchmark station very well, the translator, too. There was not and never will be skip on that translator. There was no skip that night on the 150 mile benchmark. My conclusion was - shark fins, nubs, rear window - attached to OEM - you can kiss deep fringe DX goodbye.

As far as FM antennas go - there is nothing sacred about that 31 inch whip. I always found the bigger 55 and 60 inch whips helped FM as well - a LOT! Any broadcaster will tell you their bays are 5/8 wavelength, not 1/4 wavelength. So if you want a decent FM whip, make it 5/8 wavelength.

Admittedly all this is desperation reception techniques for people like me that are totally disenfranchised and not served by local radio - and our only options are DX, satellite, streaming, and (shudder) HD. It is these options - or go without music in the car, because I refuse to listen to the slop local broadcasters condescend to offer as suitable entertainment for the masses of lemmings racing over the cliff to cultural destruction.