Some weeks ago, we published a two-piece shootout of competing FM Transmitters marketed towards iPod users, and now that Griffin has released its long-awaited SmartDeck, we wanted to create an equivalent recap of our opinions on various cassette tape adapters. If you’re not familiar with our earlier comments on cassette tape adapters, here’s a short summary.

Cassette tape adapters are today the second-best sounding way to connect an iPod to a car. To grossly simplify a complex subject, if it was possible to connect a wire directly from your iPod to your car’s speakers, you would expect to hear pristine-quality reproduction of your iPod’s sound – as good as your speakers could muster. But in most cars on the roads today, a direct “line in” connection (or its closest real-world approximation) is either not an option, or expensive. So people use alternatives – cassette adapters or FM transmitters – to pipe their music from iPods into car stereos. FM transmitters are almost universally guaranteed to have a higher noise to signal ratio than good cassette adapters, but they may be the only option for people whose cars do not have tape players.
Cassette tape adapters are easy to install. Every adapter works in the same general way. A cassette-shaped plastic device is put into your car’s tape player, then connected to the iPod’s headphone jack. Turn your car’s stereo to tape mode, and press play on your iPod. Adjust the iPod’s volume so that it doesn’t sound distorted, and then do the same with your car’s speakers. That’s all it takes.
Cassette tape adapters are the least expensive car audio option available. The best deal you’ll find on a good tape adapter will be $10 or fewer dollars, with the most expensive adapter selling for under $30. FM transmitters sell for $15-80, and line-in installations generally cost $150 or more. Because of their low prices and reasonably high quality, we always recommend tape adapters over FM transmitters if you have the option.
We have never rated any cassette adapter higher than B+. This may seem harsh, but we haven’t yet found a cassette adapter to get comparatively excited about – the mark of our A ratings. That doesn’t mean that the top-rated Sony CPA-9C adapter (B+), for example, is worse than an A- rated FM Transmitter – it just means that there has not been a breakthrough product in the cassette category yet. We expect that innovative devices such as Griffin’s second-generation SmartDeck have a better chance of breaking the B+ threshold than anything else we’ve seen, but it hasn’t happened yet.
How are cassette adapters different from one another? Our four key criteria are base level of noise, sound quality, mechanical grinding sounds, and reliability. Most of the adapters we’ve tested are very similar to one another on sound quality and reliability – only three really stand out from the rest. But they vary considerably in base noise level, and making different mechanical grinding noises in a tape deck.
“Base noise level” is the amount of noise we heard coming from the adapter when the iPod is silent. Ideally, the amount would be none, but the best we’ve heard is “low,” with others in the “medium” and “high” rangers. Mechanical grinding noises are the sounds we heard coming from inside the tape deck. Optimally, there would be no noise, but again, we heard variation from low to high, as noted below.
Sony CPA-9C CD/MD Cassette Adaptor with Self-Adjusting, Spring-Loaded Head ($14.99): Reviewed in our past Buyers’ Guides, Sony’s option remains our top pick in this category thanks to its great longevity, low base level of noise, and low mechanical grind sounds. Other than the fact that the signal to noise ratio here is comparatively high, CPA-9C’s audio sounds very much the same as the majority of its competitors. But aggressive shopping can locate it for $10 or less. B+
Monster iCarPlay Cassette Adapter ($19.95): In performance, Monster’s iCarPlay Cassette Adapter is virtually indistinguishable from the less expensive CPA-9C, boasting the same spring-loaded cassette head mechanism and the same low base level of noise and mechanical grinding sounds. Despite its gold-plated headphone port cord, which CPA-9C lacks, there’s nothing else special about its sound. Its gray body and black cable may go better or worse with your car’s interior than CPA-9C’s darker body, but on price, Sony has the edge. B
Coby CA-747 Dual Position CD/MD/MP3 Cassette Adapter ($9.95): This is the quintessential “I found it in an electronics store and bought it because it was cheaper than the Sony” cassette tape adapter; it is often sold for as little as $5, and isn’t worth that price. In addition to a medium base level of noise and a high level of mechanical grinding sound, the Coby units we’ve tested have had problems and broken faster than competitors. The only redeeming feature is a detachable, stretchable audio cable that can be positioned for different types of tape decks – unless you need it, skip the Coby. We consider this a last resort option that we would never recommend to our readers. D
Griffin SmartDeck Intelligent Cassette Adapter for iPod ($29.99): This is the only cassette adapter that stands out from the pack in features – with the right car stereo and right iPod, it will allow you to control the iPod using the stereo’s buttons. Our full review discusses the control features in detail, but you’ll want to test SmartDeck with your car and iPod to see whether the features work as you’d expect. If they do, you’ll like it more than the B+ rating we’ve assigned it, but if not, you’ll be better off with the cheaper CPA-9C, which sounds virtually identical in noise level, audio quality, and mechanical sounds. Also note that SmartDeck as currently sold is not compatible with iPod nano, iPod shuffle, or original (1G/2G) iPods, though a nano-ready version is currently being developed. B+
Belkin Mobile Cassette Adapter ($19.99): Belkin may sell more than one cassette adapter, but the one we tested (bundled with TuneBase for iPod shuffle) was not impressive. It combined a medium base level of noise with a medium to high level of mechanical grinding sounds, and stood out only in one way: its volume level appeared to be a little higher than most of the adapters we tested. That’s not a major advantage, really, and certainly doesn’t outweigh its negatives. C-
XtremeMac iPod Car Cassette Deck Adapter ($19.95): We’ve tested two versions of the XtremeMac cassette adapter, the first of which (iLounge rating: C) is no longer shipping (but may be found used on eBay or the like), and features an L-shaped headphone port connector and a medium base level of noise. The second and currently shipping version, with a straight (I-shaped) headphone connector, is a definite improvement, with a low base level of noise and low level of mechanical grind, just like Sony’s CPA-9C. Like the gray Monster iCarPlay, the white-bodied XtremeMac may stick out a bit in your car, but its black cable might not. Though we were on the edge of B and B+ ratings for this one, we’ve commonly seen the XtremeMac model available at a price comparable to the Sony, and its inclusion in XtremeMac audio kit bundles is a welcome sight for people who need the other cables. B+
TEN Technology flexDock Cassette Adapter: This adapter, bundled with the company’s otherwise impressive flexDock mount for iPod mini, is one of the worst we’ve used – but also is not sold separately. As we noted in our review of flexDock, it is unpleasant to use wth an iPod with or without the flexDock attached, thanks to low sound quality, a high base level of noise and a medium level of mechanical grind, and should be promptly replaced with a better adapter. We’ll spare it a rating because you won’t go out to the store to buy it alone, but it’s the only bad part of an otherwise excellent product from TEN.
Is there anything else I need to know? A more sophisticated way to connect these cassette adapters to your iPod involves the use of a bottom-mounting iPod accessory such as Belkin’s Auto Kit, SiK’s imp, or TEN’s flexDock, which allows the adapter to tap into a cleaner and louder source of iPod audio output. Our Spring/Summer 2005 Buyers’ Guide discusses how to do this, if you’re interested.
Additionally, performance of these products may vary based on various factors, such as idiosyncracies with your car stereo, and manufacturing differences between various revisions of one company’s cassette adapters. Based on our testing, we have been highly pleased with the endurance and general quality level of the CPA-9C, and continue to recommend it as a safe, solid option.
Our Rating