new setup

I currently have a

1 - Hifonics BXi1210D (1200x1@1ohm,900x1@2ohm)
2 - Soundstream SPL 12's (300 watts) (old school ones, great condition)

https://www.parts-express.com/soundstream-spl12-12-dvc-subwoofer--299-674

These will be hooked up via Line Driver as I will be keeping factory HU and Stock Speakers, however the stock is Harman Kardon Logic7 Surround Sound. Sounds great already.

I had them wired down to 1 ohm and they were handling the 500-600 or so watts they were each getting. hitting very nice in a 3cu ft vented box. I just recently got a new car, and it doesn't have the fold down back seats. (I'm very upset about that, lol), when I had the seats up in my old car it still hit hard but you could tell the big difference.

So on to my new car. Thinking about switching subs. possibly 1 15in Alpine R Type or similar.
https://vault.alpine-usa.com/products/documents/OM_SWR-1522D.PDF

Just wondering a couple questions.

Would 1 Alpine or any other similar 15 inch sub hit deeper and louder than the 2 12inch subs I currently have? even though the Soundstream's are from like 1999-2000.. lol they are in great condition and bang. sensitivity is nice too at 94db, while the Alpine is only at 87db

The alpine is newer and is rated at 750RMS/2000Peak and it is a 15inch. but two is usually always better than one,. but bigger is better too.

Other subs I was looking at, these are 15in below but I buys 12's are not out of the question. just examples that I was looking at.

Sundown SA 15

https://www.woofersetc.com/p-9575-sa-15-d2-sundown-audio-15-600w-dual-2-ohm-sa-series-subwoofer.aspx

Rockford Fosgate P3's

https://www.sonicelectronix.com/item_35999_Rockford-Fosgate-P3D2-15-Newest-Model.html


any comments, opinions or recommendations

thanks

well without actually hearing your current system and comparing it to what you are looking to get nobody can really say that one will be any better than the other. there is way more to it than just the size and type of sub. but i am a fan of bigger subs and simpler systems so i personally think its at least worth it to switch to a single 15 especially since those soundstreams are pretty old. the 15 type R is a nice sub and in the right box they can hit very hard and sound good doing it.

plus the alpine type R is pretty well matched to your amp because they can take a good bit more than their 750 watt rating, get the sub with a dual 2 ohm voice coil and give it all of the 1200 watts your amp puts out.

but, if you plan on putting your new subs in a simple prefabricated box then you may be shooting yourself in the foot performance wise. i would definitely opt to have a custom box built for it or at least buy a PROBOX "super bass box" for it and you should get some nice bass from that setup. the problem with prefabricated wood boxes is that they usually arent designed or built very well. they are made out of particle board and held together with nothing but wood glue and the carpet that its wrapped in.

I have been looking into Probox's, is the performance a huge difference? I haven't heard one in person. Watching youtube videos they are measuring SPL with prefab vs probox and the custom prefabs were actually 1-2db louder, no real opinion on SQ. ill keep looking though.

anyone have experience with the Sundown or new Rockford Subs? curious on how they perform.

im not sure what you mean by "custom prefab" the prefab boxes im talking about are just the generic wood boxes made from particle board that you usually see stacks of them in audio shops or pawn shops. they are anything but custom. the prefab boxes could be louder on a meter because they are usually designed to have a high tuning frequency which is better for SPL but also makes the box sound worse on music.

i havent really heard the sundown audio subs enough to have an opinion on them but i hear a lot of good things about them being loud but also power hungry. the rockford P3 subs are also pretty nice subs and they sound decent. ive built a few setups using the new P3's. they sound good and get loud and have a high build quality but i remember them just being a bit too expensive for what you get, which is typical with Rockford equipment.

prefab boxes that are built to spec for a specific subwoofer. not just a random box you find and pick up at a local shop, like you said stacked up at the stores. Any subwoofers i purchase I always get a custom made box made to fit the specs of the subwoofer(s) from what manufacture suggest.