Supra0l2d

OK guys heres the problem, I got 2 HX2 15' Rockford Fosgates subs and 1500watt amp to pushem for my Birthday...Now the subs have to have a required box size for both of them to sound perfect and that size is just to big, it will fit in trunk barely but only if i remove my CD changer, and know im discovering from other people at Audio shops that if i wana change my Head Unit, I have to change every wire and speaker running in the car (that deal with the sound)..so for the subs i have to either get rid of one of them or go down to 12' subs, then i have to funnel the sound from the speakers trough the hole where the factory sub was in order to get proper sound to the cab..all this mumbo jumbo...i just was woundering if any of you have a Kick A$$ system out there so i can get some ideas on what to do, because over here in Alabama theres really no other sc300 out there i can look at to get an idea for mine...i Mean its no civic right =P
Havin to go to Smaller subs is a last resort, i mean i really want both those 15's in there cause i know they would hit HARD.
If i had to go to 12's i would get the 12 Eclipses.

London Bill

How about a compound sub box, this allows the second chamber "B" to be smaller than the vented chamber "A" (about 50% IIRC). This is a Rockford design and you can really wind up the power as the sealed second chamber presents a damping force on the cones. The porting on the first chamber can be used to go really low.

lex400sc

That's a very unusual configuration. In this setup, it looks like the the sub in the B chamber a passive radiator. Is this correct? That'd be a waste of a good subwoofer. You could use a junk old subwoofer as a radiator.

Supra, the thing that sucks about the SC is that the damn gas tank is in between the back seat, rear dash, and trunk---which is where all custom audio stuff is centered around. If you want a really small box, try a seventh order bandpass. It couples the air of multiple out-of-phase drivers and uses them to boost sound output (but at the expense of accuracy). But any sub box is going to occupy all the trunk space (especially for 15s) unless you mold it into a nook.

If I was in your situation, I would TRY to cut a baffle out of the rear dash for the 15s to rest in. This would use the entire trunk as a cabinet which would increase air space and thus efficiency and make them knock really clean and hard. You could also mold a box into the small space between the rear dash and the gas tank and use the 10-inch opening as a giant port as they suggested. It's worth noting that you have to tune that 10-inch port right to make it sound good. This is the job of the psychoacoustic engineer, so it's not an easy task to get down right. If they'll fit, you can also fiberglass them into the spare tire well. I have dual 12s which IMO are still too big for the SC. I'm contemplating using only one of my twelves in the rear dash, which would probably sound the same as two stuffed in the trunk but with less rattling.

London Bill

I love the 7th order bandpass design & made loads of them years ago with Rockford cones, the size was a problem though. I dont know if R/F have changed the Theile/Small parameters for their cones but back then the required volume was BIG.

The Quasi-Compound design allowed us to get the power handling of two cones in a smaller box, I dont believe the second cone in the sealed chamber is considered passive though.

slowtan

2 15's in a SC300 . That would be deafing .. What kind of front's / backs speakers are you going to have.

I am planning to upgrade my speaker system in my 1997 SC300 but I didn't know what size back speakers I have . I don't think it is the Nak system. It is the system that says Lexus premium system.

I was also wondering if anyone has tried a free-air sub in the place for the 10" we have in the back and what are your experiences?

London Bill

I went for an 8" Rockford sub (1 x 150w RMS) mounted free-air in the stock location, it easily provides enough bass to complement the front & rear speaker system (4 x 75w RMS) but will not go LOW (free-air mounting has severe frequency limitations).

The front speakers are too small and poorly located, you can mount 5.25" speakers in the front door frame with a bit of work.

Keith13b

iTrader: (3)

This plan will work great, but its not as efficient as 2 seperate 15's, and doubt it will fit in the trunk. It is considerably louder than a single 15' in a volume smaller than that needed for 2 subs. Remember to reverse the polarity of the second woofer (smaller box). The confiuration shoud be a push/pull operation. Sometimes weight has to be added to the cone of the inverted speaker to make the math add up right so check the specs- this can easily be done at a speaker shop (not audio shop) at a nominal cost (<10$).

If you are looking to cut volume down dramatically, I'd recommend a straight isobaric design. But it requires insane wattages to run right. Contact Rockford for some recomendations. Screw their web site - just contact their tech support - They are great (or at least the were several years ago).

An isobar 15" box will take up about 50% of your trunk and make access to the spare cumbersome to say the least. I have basically given up hope on adding subs in an SC. The popular thing to do is have pods made for 12", that get tucked away in the pockets on either side of the trunk. The boxes are sealed (porting would be impractical due to the miniature box size). This still allows for almost full use of trunk and spare tire access and give excellent bass response. Rattling is an issue, and you will never get very low bass due to box design. Its great for sound quality at moderate volumes. But if you like straight up, drop bottom bass, our cars are just not suited for it.

I come from 4 18's ( RF pro 18's and twin power 1000's - 'old school' pushing them) all tucked away in a second gen RX-7. The bass would blurr your vission when it hit. I doubt this could be matched in an SC. So I won't even try - It'll just bring back those painful college days of sound off competitions and wet t-shirt judges handing out trophies, back when life was good and the only worries getting the car cleaned up before an event.


Keith

London Bill

There is another way to reduce box volume for 2 x 15" subs, sealed compound (isobaric).

mjames08

With 2 15s in your trunk, your CD changer isn't going to play very well anyway Skip, Skip, Skip

MadMaxSC400

I have the Nakamichi which uses a crappy free-air 10" on the back deck. I replaced it with a Kicker free-air and it sounds quite good.. the sound system is good enough that I'm not really interested in upgrading the sound system till I've got 4-5k to spend on it.

PERRYinLA

MadMaxSC400 - could you provide any further details on your Nak-to-Kicker woofer upgrade? Was your Nak woofer shot/rotted- is that why the Kicker was better? I'm wondering if I should replace my Nak woofer now or wait till it rots/dies - I'll do it now if the Kicker is a quantum improvement.

What model Kicker was it, and do you recall the price? Since the Nak woofer has an unusual frame, I doubt if it was a drop-in upgrade- what sort of custom fitting was required?

I've heard that you can cut away the insides of the Nak frame and use it to mount the new woofer- is that what you did?
(Of course, if end up doing that, too, there goes my plan to sell the old Nak sub on eBay! )

Finally- I noticed you have 80 watt headlamps. Have you had good luck with them? Some postings warn that the stock wiring eventually deteriorates under the increased load.

Thanks in advance for any help you can provide.

Lex Luthor

Perry, you will have to cut away the cone, spider, basket, voice coil, and magnet assemblies from the stock unit, cut the cone away with a razor knife, and I used a jigsaw to cut the frame apart. It's cast metal, just be patient and precise, it's easy. You will only be using the top flange and mounting provisions of the original sub, the new one will drop into the frame of the old one. Let me know if you need more details. As far as subs, the common free air 10's for this application are the Kicker, the Pioneer, and the JL Audio 10IB4. I am not a fan of free air designs whatsoever, poor control of excursion, frequency limitations (as Bill pointed out), etc, but for pragmatic reasons, I am using the JL 10IB4. Keep your tank filled with gas, it'll help the sound a bit, not kidding.
- Jon

MadMaxSC400

Yeah, the guy basically ground out the frame for the Nakamichi woofer and screwed the Kicker into it. The Nak one had some wear issues I think, it was starting to rattle. The kicker model I don't remember, I think they only make 1 kind of free-air sub. It does sound a lot better, and it hits better.
The light bulbs I've been using are Eurolites, and I switched to Street Glow recently. I've been using this type of bulb for over a year and I haven't noticed any wear or damage to the wiring or lenses.

PERRYinLA

Thanks Jon and Max for the responses. After using "Yahoo!" to search the web, I found these details on 4 10" free-air woofer options:

JL Audio 10IB4 ($129-$139) 8 ohms
Kicker Comp 01C104 ($53-$66) 4 ohms sensitivity 87.7 dB SPL
Pioneer TS-W254F ($55-$60) 4 ohms sensitivity 92 dB SPL
Vifa M26WR-19-044 $60) 4 ohms sensitivity 88 dB SPL
(FYI- More Vifa info at:
http://www.partsexpress.com/pe/showd...54448&CATID=49)

I'm assuming that, since I want to continue to use the 4-ohm Nakamichi amp, I should stick with 4 ohm drivers, although I've been mixing 4 and 8 ohm amplifiers and speakers in my home for years.

If anyone has any additional opinions or advice on these 4 woofers, or knows of any other upgrade options, or wants to chime in on the 4 vs. 8 ohm issue, or what sensitivity would match the Nak woofer, I'd love to hear about it.

Has anyone tried to remove the entire Nak 10" woofer assembly and squeeze in a 12" woofer? I realize it may not be feasible, since the gas tank might not allow enough room for the deeper woofer magnet. Plus, a new grille would have to be fabricated, and the Nak amp might not have enough watts for the 12".

lex400sc

The impedance rating shouldn't matter as long as the amp has a lower rating than the speaker (and assuming the amp is delivering ample power within it's design specs), though impedance matched systems put a lot less strain on the amp over time. It'd be a lot easier to cut your own baffle out of 3/4-inch MDF and would probably give you room to mount in a 12-inch woofer with raised clearance from the rear dash itself. I think the biggest limitation is the diameter of the 10-inch sub hole in relation to the diameter of the basket at it's widest point. The cover for the rear dash is elevated like 3-inches or so from the actual metal, so this would help out a lot. The magnet structure won't be too long as to touch the gas tank unless you're talking about 2000-watt long-throw subs like the new 10-W7.