Alan

Ryan - speaker manufacturers are often optimistic on frequency range - you really need to look at how linear they are over the range they quote...

I suspect based on size that these roll off substantially @ 30Hz...

You want a good flat level across all the audible range (and below for a true sub)... sacrificing audible range flatness for more in the sub-range is a poor trade off for overall sound quality... so the biggest issues will probably be how flat will you be in the 50-3K range if you go with these and just mid/tweeters in front... that will depend on the speaker choices you make all round...

If you have a single sub you will still ideally need 2 pre-amp channels (L/R) to feed it vis a summing active cross over and then a single channel or amp. Or a dual channel/crossover amp than can be bridged to effectively sum its inputs?

Low bass is not perceived very directionally - so you can use a single driver for it - but you still want to hear all the bass on both channels... (ideally sum the bass from all 4 channels - but front rear are not likely to be much different for common sources).

As for ohms you only need to make sure the amp ratings (incl those in the head unit) and the speakers match.. check under what conditions the amps can make their rated power - and use those impedance speakers... if you use higher impedance - you may never be able achieve full rated power (volume).

You need to look at the impedance of the passive crossovers wherever you are using them rather than the speakers attached to them...

Alan

RyanPerrella

Alan,

If I go with those 6.5" speakers i mentioned i would have them along with the components in the doors, but also another set of components in the rear qtr panels for a total of 10 speakers. Would 4 x 4" 4 tweeters and the pair of 6.5's that i would be using for bass not be an effective comabintion in your estimation?

If its not, what should i be looking for? Again I already have 10 speakers in the car now, i will rewire everything but ive got the holes there already. I want to really just replace the 1991 year speakers in the car with new ones. How would you outfit this car ideally? How would you then outfit this cars speaker systems on my budget $300 for speakers or $500 adding a sub and amp.

Any comments on the Polk DB series speakers? (edit: they dont have a 4" component speaker set)

RyanPerrella

To add to what i am looking for, here are a couple points to consider.

1) the budget, i want crisp clean sound, not looking for anything showstopping, just want to replace 16 year old speakers

2) I dont want to get involved in doing any dynamat or anything like that. So I dont want to buy things that because i bought them, i should feel the need to optimize the car to work with them.

3) I already have 4 x 4" holes, 4 x tweeters, 2 x 6.5" So i want the correct range of speakers that will fill those holes and fit restriction #1, the budget.

4) I prefer not to use any amps but if i need one to power the 6.5's then i will find a place for it. (Suggestions on smaller sized 2 channel amps for under $100 appreciated)



I have found refrence series MB quart speakers on Ebay for $85, which is less then the new for 07 Polk units i mentioned before, but i look at things like sensitivity as i want to power the 8 component speakers through just the head unit and the polks 93 are much better then the MB Quarts 85. Is this something i should in fact be paying attention to or do i just ignore it?

Alan

Ryan - its impossible to say in general - you need to look at the frequency range & flatness of the combination you plan to install - as long as the front & rear components sets ~match the woofers or more likely if you can adjust them in some way (e.g. via overlapping speaker frequency capabilities and a variable freqency cut-off on the X-over for the woofers). Then likely you should be fine. You should certainly be able to find many speakers that will work fine together in these combinations...

My set up is similar in some ways to the speaker set-up you are considering:

I have component sets (passive X-overs) in each door and the same in the rears configured as I mentoned previously, I also have 6.5" woofers in the B-Pillar and an 'almost' sub-woofer in the passenger door..

I also have 2 quad channel amps - which is different from your proposed set up but this gives me not only more potential volume - but much more controllability of levels and frequency cross-overs. Both amps have full active crossovers so I can set individual channel levels and frequency cross-overs (both high & low cut) this lets me match the speakers characteristics much better.

I use 3 channels per side: 1-the front door component set (low-cut), 2- the rear deck component set (low-cut) and 3 the 6.5" woofer (low-cut & high-cut) Then I have the 2 remaining amp channels bridged and summing all 4 channels (high-cut) for the sub-woofer.

Aside from the sub-woofer you will effectively also have 3 channels per side 2 from the head unit and 1 from an extra amp.

(BTW You will need to amp the woofers seperately regardless of adding a sub-wooer and its own amp in the spare tire well... if your head unit also has a sub-woofer pre-amp output you are lucky that will help).

All my speakers and amps are a/d/s/ which gives some consistency to the specs between them - but this kind of active set-up could fine tune almost any speakers that could possibly work together...

However although its very flexible its still a pain to set up initially...

You will have less flexibility so need to be a little more careful on the selection of well matching components. Possibly just look to the same manufacturer for pre matched sets...

Does your head unit allow variable freq cut off on the sub-woofer output if you have one?

As with many things - the deeper you get into it the more options and considerations - you quickly get into the $1000+ range

But - good quality used equipment is still availabe cheap (ebay etc) - but then you have to know what you need and be a little patient...?

On amps and speakers - some of the older brands/models are still actually amongst the best performers (but not so on head units etc)...

Alan

RyanPerrella

Sorry, the components are the 4", I was measuring the grill and got 5 1/4 but i was in an audio store today and looking at 5 1/4 the complete speakers are sloser to 6.5" so obviously i was measuring the wrong part of the speaker. I will edit the previous posts.

RyanPerrella

I think I have decided on what speaker sets to purchase, but It maybe a project i do in a couple weeks time

I am going to go with 2 sets of the 4" MB Quart components, PCE 210, along with the pair of kicker 6.5's mentioned before. I was looking for a narrow amp to run those and am looking at an MTX and an older alpine, both rated about 50 W RMS x 2. I am thinking of making a longer pass side floor cover (the one that the tailgate switch mounts to and which hides the factory amp) to house the 10" long amp. But if I dont want to go that route, i think maybe a better option is to remove the spare tire, or just remove the air compressor (although without the compressor there is no use continuing to carry the spare) and mount the amp in that location. I guess i will try that for the time being and if i need more bass i can build an enclosure to house a large sub and another amp at a later time.

RyanPerrella

I wanted to post an update to my now complete audio makeover.

Ive got 2 sets of the MB Quart PCE210's, and am looking at either the add a woofer 6.5" mb quart or i will buy a set of PCE 216's to use the premium 6.5" woofer in the b pillar. running the speakers off the headset which is 50w max to 4 channels 20 RMS. The rear will runn off a 3 way passive crossover which will run a 1" tweeter, the 4" and the 6.5" all of which are mounted in the qtr panel.

For bass I bought an Infinity Kappa 10", which will run off a rockford fosgate amp and will be constructing a box to fit in the spare tire well.

I am considering making more of these boxes and reselling them if there are others interested.

Am i pushing it trying to run a 4" a 6.5" and a tweeter through a 3 way crossover through just the stereo amplifiers 20 w RMS? I am not into volume, i just want clean, crisp, clear sound. I dont need to blow my ears out.

Alan

I agree with Sterling here. You'll need more power to the 6.5"s - I'd still suggest you amp them seperately and combine just the other two on the head units rear channel per side.

Alan

dr bob

Ryan--

One thing you'll discover quickly if the previous installer/owner didn't is that the factry power leads to the radio head unit are way too small for use with a powered head unit. Be sure to upgrade the power wiring for the head unit if you plant to use it to directly drive speakers. The original setup had that awesome external amp by the passenger seat, so the head unit needed only enough juice to light up the buttons and run the cassette motor. In typical German fashion, the wiring was sized perfectly for that load... and no more.

RyanPerrella

Glad you brought this up Bob.

The car has what looks like the speaker wire i run in my home stereo. The clear vinyl wrapped silver colored and gold colored wires. What gauge is good for the speakers? And what kind of wire should i be looking for? I bought 50ft of the wire thats already in the car, i plan on rewiring the entire thing but what kind of wire should i use for the speakers? Is there a current norm without spending $1 a foot on wire. The wire i bought was $0.10 a foot, i could go to $0.50 if its worth it.

What do you think?

VehiGAZ

My suggestion is to amplify all of your channels - MB Quart crossovers are notorious for needing a lot more power than a headunit can provide. You will not get clean-but-quiet sound running off the headunit, just quiet sound. I think Alan's suggestion of amping the rear channels might be a mistake - you will get a lot more sound from the back than the front that way, and you will likely end up hearing only one set of front speakers, making for a poor "sound-stage".

I would suggest to shoot for 4x50W rms for the Quarts and a bridged 2x100W amp for the sub to get good sound without overdoing it too much. (Btw, max power ratings are nothing but lies! RMS is the only thing you should look at.) But I would also suggest going with a higher-end 8" sub instead of the 10" - you can get away with less amp and a smaller enclosure and still get nice, full sound with no boominess.

If you are going to put a sub in the spare wheel well, you will lose the room needed for two amps, though.

Radio Shack wire-by-the-foot is fine. 18g to the rear crossovers is probably enough (not my area of expertise, though). If you do any rear amps, you will need good shielded RCA cables to get you from the headunit to the amp in back. Radio Shack used to make some fine shielded gold-plated RCA cables, but I haven't checked there in a whiles.

I realize this isn't all entirely helpful, but you will see that there are no short, straight roads to a great sound system.

Bill Ball

Ryan:

You say you have holes for the 6.5s that are "somewhat enclosed". The rear 6.5s are in an OPEN area. Essentially free air, communicating with the wheel wells. I've tried all kinds of heavy-duty 6.5 woofers, such as the highly regarded JL Audio 6W0. I cut the area behind this to fit the huge, deep magnets. The sound was muddy and useless even with a honkin' amp. These speakers are not intended for infinite baffle areas like this. I stuffed the area with polyester. I tried sealing the chamber - I theory that could make these speakers work, if you could devise an effective seal and get the right volume. I tried water pipe insulating foam sections fit down into the periphery to create a seal. I tried other 6.5's that were 2 ohm like the original. They all failed in this application. The best sound was with some mid-range MB Quart components. Very nice mid-bass, made even tighter with polyester stuffing. But they still were missing low-bass. A small underseat sub, such as from a WRX actually works very well, but won't fit under the 928 seat. Anyway, if you are intending to avoid a visible sub, try to find 6.5s that are for an infinite baffle area. Good luck. I haven't tried sealing the area with expansive aeresol foam. Others have used that for cutting down tire noise there. Maybe that would work better to create a sealed chamber.

I did find some small 2-channel amps for powering a sub or the rears that would fit under the passenger side amp cover. Not sure if they are around anymore. They were an off-brand, but they did fit: one of them was the Pyramid PB-110X. Here's somebody still selling it.http://www.tougi.com/newproduct/view...fo.jsp?id=7372

I also found a 4-channel 75W/ch RMS amp that was only an inch thick and would slide under the driver seat, but it was 14 inches long, extending into the rear foot well. Farenheit CLX730-4. Actually worked rather well. So thin, it might be hidden elsewhere or you could just box over its rear end and lose only an inch or so in the rear footwell. I've not seen a thinner amp. Fareheit used to make a much shorter lower power version, the CLX520-4, but I haven't seen it for sale anywhere in a couple of years. A CLX730-4 is on eBay right now. Inexpensive but effective and very thin.

Anyway, I'm still trying. The other challenge is a center speaker for 5.1. I am deeply in love with DVD-Audio and DTS multichannel audio and I have several headunits that support this. I have installed such a setup in my Durango, and it it the best car audio I've ever heard. Trying to replicate it in the 928 while keeping it stealth has been a frustrating project.

Alan

GAZ,

Remember Ryan said "a budget system"... he also claims he doesn't need loud...

The primary issue of driving a triple X-over to MBQuarts is the low efficiency drivers and X-over loss. so the rear channels (and the only true mid range drivers) will end up too quiet. Amping the 6.5" seperately with another ~20-25W RMS /channel should balance that out without too much extra expense...

As long as the amp isn't extravagent w.r.t the head unit power a balance should be achievable.

I agree to build a high end system you'd amp everything with active cross-overs - but that gets expensive really fast....

Alan

RyanPerrella

well the budget was blown, ive since doubled my budget with the seperate 10" sub and the amp to power that.

I think ive got the actual speakers right, and the sub and its amp. Now I guess i just need to add another amp, this time a 4 channel to at least double the 20RMS the stereo puts out now. I was thinking of putting it on the floor behind the passanger seat. and then boxing over it and carpeting it. Ideally i dont want to use another amp, but if i can find one small enough then i will try it i guess.

If the price continues to escelate i will just sell all this stuff and keep the 15 year old polk speakers that are in the car now and run with that, this is getting a little out of control honestly. I bought specific 3way passive crossovers to power the rear channels, but if i have to start getting into active x-overs i will jump off a bridge. I dont want to do all that stuff, there just isnt any space for all this stuff. Ideally i wanted no amp and no sub, but the spare tire is completely useless to me so i may as way take advantage of the space and put a sub in there.

I think i may try the 10 speakers off the JVC head unit, and if it needs an amp for optimal sound, i can always just add the 4channel amp later and rewire the thing.

Bill, I am no longer trying to get the 6.5" holes for all my bass, i am adding an enclosed subwoofer for the spare tire well.

VehiGAZ

Aaaahhh... now I understand what you were getting at, Alan. The front 2-ways on the front channels, the top 2 of the 3-ways on the back channels, and bottoms of the 3-ways (i.e., the 6.5's) on an amped channel, right? Now that's thinking outside the box!

In the interest of full disclosure, I have to admit that in my truck, despite my advice, I have headunit power to the front end, a little 2x75W bridged amp under the seat, and a tiny Focal sub in back, and it sounds plenty good! I'm still leery of trying to run MQ Quart separates on headunit power, but you never know...

The Kicker amps I'm getting for my install are very small and thin.

Good luck Ryan!