I'm a complete car audio newbie and have some questions that I couldn't really find the answers for in the forum...

I have a 2002 P5. I'm planning on getting an Alpine 4 ch. amp (MRV-F340, 55W x 4) driven off the stock HU. For speakers I'm planning on Infinity Kappas (5x7 x 2 + 6.5 x 2).

Now my questions are: (I'm into good sound quality so the system doesn't have to be awfully loud or anything.)

1) First off, how are the amp and speaker choices for my goals? Overkill? Too cheap? Just right?

2) I'm not using a sub for space and cost concerns. Is this OK keeping in mind that I don't need the system to be loud?

3) Since I'm not using a sub, I'm thinking of using the rear 6.5 speakers to produce much of the bass while keeping the fronts off the bass. Is this how it works? I have this nagging feeling that I would be "wasting" the rear speakers if I only get them to do bass or mid-bass duty. (Again I'm a total newbie and don't really know what I'm talking about.)

4) If in response to question 3 your answer was to use the full range for all four speakers then ignore this question. If you answered that I should send bass to the rears, should I consider some other speakers?


Thanks very much for you guys' expertise. I've learned a lot about car audio from the forum from you guys

 

alright, you choise of speakers and amp is good. the alpine is gona be be pricy, so if your not getting a discount on it, i would go with something else unless you just want to spend the cash infinity makes great speakers, but they lack bass. without a sub i think you will be disapointed. you could always get 6.5 rockford subs and just run those in the rear doors. definatly get component speakers for the front, which means that you would have to get the 5X7 reference speakers or 5.25 kappa speakers.

 

I'm going to agree with walight here.

Infinity speakers sound GREAT, but they are lacking in the bass.

What I would consider, seeing as how you are not installing a sub, is using some mid-bass speakers in the rear doors.

You can get dedicated midbass speakers in 6.5" size. They will help out your bottom end, while keeping the midrange and treble sound as much "up front" as possible - which is where it belongs.

I don't know that amp, but a setup like I described is EASY to accomplish, so long as you get a 4-channel amp that has separate crossovers for the front and rear channels. You will high-pass the fronts, taking the low bass away from them. Then low-pass the rears, giving them only bass frequencies. The exact crossover frequencies (cut-offs) will depend on what sounds good to your ears.

And this doesn't have to cost a lot of money. I just picked up a set of Peerless 6.5 midbasses from madisound.com for $38.50 each (so $77 for the pair). I have not heard or installed them yet, but they were highly recommended to me by several people for this purpose.

~HH

 

Thanks for the info guys.

I never knew there were such things as 6.5" midbasses. What other companies make them? And how do I tell if they are suitable for this purpose? From searching around the net I couldn't find many of these types of speakers... maybe I'm not looking at the right place.

hihoslva: the peerless 6.5 midbasses you were talking about... what is the mounting depth?

I just checked madisound.com, were they the "autosound" woofers?

 

First - you shouldn't have any issues with depth whatsoever in the rear doors. I think there's something like 4 inches in there - much deeper than the fronts, and no window interference.

I know that Kicker makes some mid-basses also. You can try searching Crutchfield if you want, though I'm not sure what info they might have there....

The Peerless is the "autosound" woofer line - The model I bought is 850518. 4-ohm driver - looks to be very nice.

Small mid-bass speakers like this are probably the most overlooked area in autosound, I think - there just aren't many companies making stuff for this purpose. However, you CAN use the woofer from a component set (separate woofer/tweeter) for this purpose, also - low-passed from the amp. Of course, a dedicated midbass is a better option, because it's specifically designed for use this way.

I've heard great things about both the Peerless and Kicker's Resolution midbass. I went with the Peerless because it's a bit cheaper, and came highly recommended to me.

And hey - check this out: http://search.ebay.com/search/search...&query=midbass

~HH

 

If you are in to SQ, then I am really surprised at your keeping the factory head unit. When replacing the head unit alone, you can notice a pretty big difference in SQ with the factory speakers alone. The amp and speaker choice sound good, but you could also get a more affordable Alpine 4 channel amp, a mono amp, and a single sub (10" in a prefab box). I think you would be ultimately happy with that. Trust me, once you start on your system, you won't stop until the toughest critic is satisfied---you! Also, you could ditch the rear Kappa speakers for midbass or go with Infinity Reference spkrs. that are run off of an aftermarket headunit. Then if you decide on a 4 channel amp, you can run your fronts off of it and bridge the other 2 channels and run a single sub.

Michael

 

lol, well you don't have to have 'subwoofers' to complete a system cause more or less, however MisterT's solution raises a mildy good point. i run my two rockford 10 inchers off an old 50x4 (100x2) jbl four channel amp and they ****** shake the car apart. so running your fronts off the amp and a single ten off the other two channels can give you some nice tight bass. rear midbass drivers...eh, it's all personal opinion, cause like for me, while i do believe the front sound stage is most important, i do love to hear some rearfill out of my bostons, even if it's just high frequencies, i like to hear something from the back.
or since you like infinity products, leave yourself the future option of getting an infinity basslink sub in the future, small compact install and very good sound. different strokes for different folks.
peace

 

Thanks for the comments.

After careful consideration I'm thinking of doing this:

Amp the front Infinity Kappa's, leave the rear speakers stock and run them off the stock HU, bridge the rear channels of the amp and run a sub.

1) How's this setup? Is this OK or should I amp all four corners and put in a mono amp for the sub?

2) Sub size and make/model suggestions?

 

This is a very common, solid, and economical plan.

Before suggesting a sub - as there are so damn many out there - tell us what you are looking for. Do you want it to be loud? Mellow? Booming? Tight and smooth? And how mych power are you working with?

~HH

 

Hmm... I can't really define what kind of bass I like. But I auditioned a JL 10W0 at a local auto sound shop and they sounded to my liking.

This sub came highly recommended by others for sound quality and also for its performance in low power setups. (The amp is a 55W x 4 and I will be bridging the rear channels for the sub.)

Pros/cons of this sub?

Resources for box-building?

Thanks.

 

Agreed - the JL W0 is a great sub for relatively low power.

Allrighty - so you know your sub. And your amp is a great match for it, too, as it will handle 125 watts RMS, and your amp should be laying down 110 or so. That'll do very nicely!

The 10W0 has a nice range of box sizes you can go with. If you like "musical" bass (meaning NOT booming loud, and a well-rounded sound suitable for listening to all kinds of music), I would absolutely go with a sealed box. They are simple to build, cheap, and sound great. A ported box can be much louder, but it is "peaky", because a ported box is tuned to a certain frequency. So there is a boost in bass around that tuning frequency. They also take some calculations and design to build properly.

I'm guessing you'll want a sealed box. Most non-bassheads do, IMHO.

The range of sealed box size for the 10w0 is .5 to .9 cubic feet. I personally would try for the larger end of that scale, or even slightly more. This will give you a little better response on the real low stuff. Sealed boxes are not "tuned" per se, but the smaller the airspace, the more limited your output will be in the low frequencies.

A 1.0 cubic foot box would be nice - once the displacement of the driver is accounted for, you will end up with just under that 1 cube volume, between .9 and 1.0 - should sound pretty good!

Box building is easy if you just go with a simple MDF enclosure. The more elaborate you get, the more difficult it is to build.

Not for nothing, but if you are gonna buy a 10w0, why not consider one of the pre-loaded JL boxes? They sell two models with a single 10w0 already installed in a proper size box. Hit www.jlaudio.com, then look under "enclosures". You'll find 'em.

For relatively low-power applications, pre-made boxes are just fine - even the ones you can find locally. If you want to build your own, it's easy - just use 3/4" MDF, do some math, and you're all set. For something more custom, you're gonna have to use some imagination....

The JL sounds like a good plan, though!

~HH