So I've read a few threads on here recommending the RX7 FD alternator as a good NA swap but can't seem to source one properly. I've found this one on Amazon from DB Electrical for really cheap and I don't see any negatives being said about the company.

Can anyone confirm if this is the alternator people tend to go for? Reason for the upgrade is I've added a new audio system and I don't think the stock alternator will do too well with it. I'll be pulling about 500-600W RMS (not much compared to most people's systems)

Is this the right alternator or do I even need one for the audio system?
For what it's worth, I'm adding a 2000W amp to power two polk db6501s at the door at 200RMS for the pair, and one 8in polk footwell sub at 300RMS. The headrest speakers are wired in series to the head unit and not to the amp because headrest speakers

 

I can't speak to the audio system needs or compatibility but I put an NB2 DB alt in my NB1 about a month ago and all good so far - unit seemed well made.

 

I just did this on my VVT swap.

I ordered one from eBay from ace_alternators which seems like a legitimate quality company.

I then ordered a new mounting bolt since the flange design is different: M10-1.25 x 110mm JIS Hex Head Flange Bolt (from Amazon). But you can use any M10-1.25x110mm bolt

I also bought this belt (Bando USA 4PK890 Belts) that is slightly longer so I didn't have to modify the casing of the alternator. The alternative is to grind the casing of the alternator at some contact points so that you can use the stock belt.

Hope this helps!

Here's an older thread where alternators were discussed with photos. https://www.miataturbo.net/general-miata-chat-9/alternator-options-opinions-73830/

 

Did you get one like this?
https://www.ebay.com/itm/1993-Mazda-...ox!29072!US!-1

 

Yup that's the one I got. Ace Alternators in Whittier CA gets good reviews if you look them up, so I felt pretty comfortable about ordering from them.

 

Not bad pricing either.

 

Install the system first then determine if you need the upgrade. I did audio installs for years and don't recall ever needing an alternator upgrade for 600w rms.