Alpine Sps171a Front Components

[Abbas]

Hi,

As I had some spare time this afternoon thought I would install my set of alpine components that have been sitting around for the last few months. I bought these from a on line ice store for about £75 inc delivery.

Had a power cut (whilst I as drilling holes for the spacers) then it started to snow so I only managed to do the drivers side.

Wiring

I connected the lime green wire into the crossover + and Turquoise into the -. The woofer + to crossover + and negative to negative using the wires I took off the tweeter to speaker OEM set-up (red and white). Then wired the Alpine tweeter

I wired the black wire with stripe from the tweeter to negative on the cross over and the all black wire to positive was unsure on the polarity as it was not stated anywhere on the tweeter nor the wire so tried it.

All connections made were soldered.

The Alpine woofer and tweeter can hardly be heard over the passenger side stock speaker unless I change the balance to -5 passenger side then its about equal. In my opinion the stock speaker sounds a lot louder, sounds better and it distorts less. I know this cant be right the stock is a 15watt rms and the Alpine is 50 rms with a 2 way crossover over the very basic stock one.

These speakers are suppose to work well with or without amplification, my amp wont arrive till next week but surely the speakers shouldn't sound that bad?

Set up prior to installation - all stock apart from Sony CDX-GT710 head unit 17watts rms with amp bypass cable.

I set the crossover to -3db (options 0,-3,-6db).

What have I done wrong? due to weather cant be taking it apart yet, plus putting the door card and tweeter back on is a nightmare for me!

A Pic before putting the woofer onto the autoleads adapter.

Thanks,

Abbas

[sparkystav]

We need pics!

[Kazi]

What advice are you seeking dude? Have I missed the question? :duh:

[redz_UK]

was thinking the same thing mate!

[Abbas]

was thinking the same thing mate!

Guys sorry the post was incomplete just having a bad day. If you look up now I have completed and added the only pic I have for now...

[Abbas]

Soon as I get a chance to check all wiring and adjust the attenuation settings also I will try what swapping the tweeter polarity does...

Hopefully it is something simple.

[aztecbandit1]

Here you are matey, these are the main feed wires for the front speakers that go into the power connectors on the crossovers, so you can check which wires you have as the main feed? :)

Front right positive = LG- light green wire colour

Front Right negative = B- Blue wire colour

Front Left positive = P- Pink Wire colour

Front Left negative = V - Violet Wire colour

[Abbas]

Here you are matey, these are the main feed wires for the front speakers that go into the power connectors on the crossovers, so you can check which wires you have as the main feed? :)

Front right positive = LG- light green wire colour

Front Right negative = B- Blue wire colour

Front Left positive = P- Pink Wire colour

Front Left negative = V - Violet Wire colour

Thanks,

That's the same as the diagram I followed I will double check but I can clearly remember following the above. I guess I will have to double check everything and put up with the sound till then.

Is it possible that this could be the ressult of my bad soldering skills

[redz_UK]

it could be poor soldering giving a poor connection..

it could also be the way they are mounted.. its difficult to tell on the pic but the mounting ring should be flush and effectively 'seal' to the door. it helps to use some kind of membrane between the door and mounting ring. Draught excluder, silicone sealer (one left to set), or similar can work well.

[DJ Wozza]

as mentioned above the seal should be as airtight a possible between the door/spacer/speaker,

sounds like there may be something else wrong here.

Have you tried reversing the polarity of the tweeter and either/or altering the tweeter output to 0db ?

-3db will make a massive difference in tweeter output mate.

For instance, suppose we have two loudspeakers, the first playing a sound with power P1, and another playing a louder version of the same sound with power P2, but everything else (how far away, frequency) kept the same.

If the second produces twice as much power than the first, the difference in dB is

10 log (P2/P1) = 10 log 2 = 3 dB.

so that works out that you are halving the tweeter output for the -3db cut !!

[Abbas]

Thanks guys that gives me a few things to check out and work on, I do regret changing the attenuation to -3db as I had 3 options I went for the one in the middle, I will try 0db and then test it then try reversing the polarity of the tweeter.

I will also check the seal between the door and adapter and see if I can seal it, if needed.

[Abbas]

I set the crossover to 0db and it made a difference sounded better the polarity on the tweeter does not make any noticeable difference to me.

The door card has some panel clips missing and does cause some vibration. I think when the amp comes and gets connected it will sound a lot better as the Alpines are really underpowered at the mo and the stock are 2 watts overpowered so they are working at full power.

May get some Dynamat, but as its expensive will research on how much difference it makes.

[redz_UK]

dynamat makes the most noticable difference..

its almost like putting a new set of speakers in.

[Abbas]

dynamat makes the most noticable difference..

its almost like putting a new set of speakers in.

Is it possible to take off the inner door panel to get to the outer part to cover that with dynamat. I notice the difference when I drove with the door card off for a short period. A lot of road noise came through so I was thinking how quiet it would be with dynamat on the front doors.

[Mitch007]

I was surprised at how cheap Halfords was for dynamat. If you need bigger rolls mind think you're best bet is eBay.

[DJ Wozza]

It is quite tricky but you can get a big sheet inside covering almost entirely the whole door mate.

(you need a mate with small hands)

[Abbas]

It is quite tricky but you can get a big sheet inside covering almost entirely the whole door mate.

(you need a mate with small hands)

Okay so you need to stick it to the door through the gaps? That sounds like a challenge, does it make a lot of difference and off the top of your head how much dynamat would you need and or how much would the cost be for doing both the front doors?

I think I may give it a go depending on cost?

[aztecbandit1]

There are a few types of sound deadening material matey? (you prob allready know) but you can get brown bread type and there ar a few places that do big rolls of it on eBay if you have a search? theres even sound deadening paint you can use :)

[DJ Wozza]

Okay so you need to stick it to the door through the gaps? That sounds like a challenge, does it make a lot of difference and off the top of your head how much dynamat would you need and or how much would the cost be for doing both the front doors?

I think I may give it a go depending on cost?

I can't honestly remember how much it was, mine was done in one complete sheet (2 layers), fiddly & time consuming

but worth it over small strips in my book. I think it was a door pack, but really can't be certain.

Basically the rear of the sheet was scored into about 3-4 strips just on the backing (not cutting through the Dynamat)

horizontally. Then the little foam bungs that are between the crash bar & door skin were removed. The sheet was rolled

up starting at the top of the sheet downwards (so when unrolled it would have the writing the correct way up).

This roll was placed in the door cavity above the crash bar and help up in place, then it was very carefully un-rolled

with the bottom of the sheet being aided by gravity as it goes down behind the crash bar. When you are happy with the

location being correct against the inner side of the door skin (here comes the fiddly bit !!), you gently start to remove

the horzontal scored strips covering the adhesive backing. Oce the top one is off and the sheet is held in position, it will

get slightly easier removing the other strips. U can use a wooden spatula stirrer thing from the kitchen to press gently on

the back of the dynamat to get a good seal. It's nice & thin and has a flat end. Try not to get any air bubbles/pockets as

they will reduce the Dynamats effectiveness.

I would suggest you take off the door panel and have a feel inside the door cavity to give you an idea how big a sheet you will get inside in one peice without hitting any obstructions. Probably easier with a mate on the other side of the door

to help with a tape measure. Then see what Dynamat you will need. Like I said above I think it was 2 full Door Kits I used,

but better off checking for yourself to be on the safe side. Once done see what you feel the result is like, you may want to try second sheet on top, but that is up to you, one sheet may well be enough :)

Hope this helps :)

EDIT****

you may find it a little easier removing the woofer & spacer to allow you a bit more access inside the door cavity