RD0202-1 Tweeter for Monitor 4A on Ebay?

printboy

Found the below being offered on Ebay which seems to be the tweeter used in the 4A and the VS Series of speakers. However, I believe the 60 watts rating is higher than the Polk issued version which is 40 watts? I guess that wouldnt make a difference?

Also this tweeter was first produced in Japan and then I believe later in Taiwan. Does anyone know if the Japanese version is possibly better than the Taiwanese one, as I read on this forum somewhere that the Japanese version had a slightly larger magnet? Would that make a difference sound wise? Another guy on Ebay is selling new old stock Japanese tweeters and stating it was superior to the later versions. But I know to take Ebay product descriptions and comments with a grain of salt.

Just curious as I am looking to possibly get a couple of tweeters to keep in reserve just in case as they are relatively cheap. I intend to keep these speakers for a long, long time as I just had the crossovers upgraded and know there is no drop in replacement for these tweeters.

Thanks for any thoughts on the matter.

https://www.ebay.com/itm/3-Super-Dome-20mm-Tweeter-Square-frame-with-Mylar-Cap-Crunch-USA-60watt-peak/263608122211?hash=item3d6044bb63:g:ebIAAOSwHOxa0mBh

wolfie62

Back in 1990 I purchased nearly identical tweeters, see pic. But back then, they were made in Germany. The ones you show here look like copies. If I recall, on my Monitor 4As that I bought in 1986 (and still have), the tweeters say "made in Germany."

These little speakers I made in 1990 are very, very good speakers for everything but low bass. I gutted the Radio shack components and used the ubiquitous Peerless 5-1/4" midwoofer and this MB Quart (I believe) tweeter. Got both from Meniscus.

I would search for the German version of the tweeter and not go with the Japanese copy, if you can find it.

wolfie62

Also, the tweeters you show on eBay are for car audio, meaning 4 ohm most likely. You would need to find the 8 ohm version as a replacement, unless you want to run two tweeters per speaker.

printboy

Thanks for responding to my post and your recommendations but one cannot put in an 8 ohm tweeter in the Monitor 4A; its just not compatible. Your tweeter in the photo looks very similar to the RD-0202 (which has a square bezel as well) but since it is 8 ohm it will not work. There is no direct replacement for the RD0202 hence my question asking if anyone knows from experience if one country of manufacturer may be better than another and why one tweeter would have a larger magnet.

I believe the Peerless tweeter in the first version of the Monitor 4 was 8 ohm and that tweeter is not compatible with the 4A as well even though it used the same MW as the 4A as I recall. Maybe that is the reason you recommended an 8 ohm tweeter in that you thought mine had the peerless tweeter which it does not and never had.

wolfie62

No. I have a pair of the Monitor 4As, I bought new in 1986. That is what inspired me to find the tweeter I used in the pic above. It was much cheaper than the silk domes and soft dome tweeters at the time. When I sent in my warranty registration card to Polk, I asked them why they were not making their own tweeters--these were made in Germany. After that, Polk quit use of the Peerless domes and this one, and poured R&D money into making their own. Or at least, specifying their needs to another mfr. Probably a coincidence on the timing and my comments.

wolfie62

My point is that if you can source an 8 ohm, most likely you can source a 4 ohm version. That is, if you are talking to the OEM and not just a distributor. But, yes you can use an 8 ohm version; you have to change the crossover components, and take into account sensitivity of the driver. The 4A uses a nominal 6 ohm driver with that nominal 4 ohm tweeter. All you need are a few resisters to change the dc resistance, or make adjustments. Depends on how versed you are in the electronics.

wolfie62

Actually, according schematic, I’m wrong! Both are nominal 4 ohm drivers. Confusing, my 4As say rated 6 ohm.

printboy

Just discovered on good authority, that the original tweeter for Polk Monitor 4A, the one with the square bezel, was manufactured by Tonegen in Japan a leading OEM speaker manufacturer at that time prior to its acquisition by Foster in the late 1980s. Production was shifted to Taiwan and again my source says the quality of this tweeter is far inferior to the one made by Tonegen. In fact he called it "rotten." In another post on this forum someone mentioned that the magnet size was different as well. I wonder if that may be a reason the Japanese tweeters may sound better? As some may know this tweeter, made in 6 OHMs instead of the Polk 4 OHMs, were used in speakers by KLH, Cambridge Sound Works and others, but were the ones made in Taiwan.

Naturally the Japanese tweeters can easily be identified since they are labeled Japan on the back but also by three evenly spaced dimples in the recessed circle below the dome on the bezel face plate. These dimples do not appear on the Taiwan faceplate as far as my research has indicated. It appears these dimples were created when the tweeter contact points were attached to the back of the face plate. Thats my conclusion.

Just purchased a pair of NOS Tonegen/Japanese 4A tweeters to replace my Taiwanese ones and will report back if they are in fact better sounding. Westmassguy upgraded my 4A crossovers almost a year ago and that in of itself made a big difference in the sound of this modest little speaker. At the very least need to replace them as the bezel corners on my original tweeters around the screw holes are cracked from over tightening most likely. Live and learn.

tonyp063

Just discovered on good authority, that the original tweeter for Polk Monitor 4A, the one with the square bezel, was manufactured by Tonegen in Japan

Citation & attribution please.
Thanks.

printboy

Sorry my bad but I misunderstood and assumed the 4A tweeter I ordered was NOS made in Japan by Tonegen but is in fact a "replacement" tweeter reportedly made by Tonegen. The replacement tweeter has the exact same size face plate and a three arm phase plug in front of the poly dome like the original 4A tweeter but with a different flared arm design. It is noticeably better made as well. faceplate is much more solid feel.

When comparing the two the replacement tweeter is brighter and open and not congested or dull sounding like the original tweeter. Maybe a bit of warmth is lost but... the tweeters didnt cost very much so will have fun playing with them. Unfortunately, due to space constrictions I am not able to use larger speakers as I would get like monitor 5jrs Series II. Not even the Monitor 4.5s will fit in my set up. Like to see how they compare to 4As. Another time another place with more room.