amplifier help

In car entertainment: stereo; speakers; portable devices etc

Moderator: Scirocco Register

steve bain
Posts: 628
Joined: Wed Apr 15, 2009 11:01 am

amplifier help

Post by steve bain » Fri Oct 21, 2016 4:50 pm

right. i am soon reaching the cable laying point of putting the car back together so need some help. I used to know loads about ICE but have forgotten all of it!

I have 5" componant speakers in the front doors with crossovers and tweeters mounted on the under trays. I can't remember the brand but they were about £100 so must be fairly reasonable so will be reusing those.

I have Infinity 6x9s in the rear parcel shelf. This is a full mdf shelf and before someone says it, they are stealth so can't be seen! i'll reuse these

I have a 12" rockfort fosgate punch sub in a custom made fibreglass box that fits in the drivers side recess so will reuse that too as its a good fit and doesn't take up loads of space

i have a massive amp power cable i bought years ago and used it to power 2 amps. One i sold and the other i still have. Its a Pioneer and is not massive 2x35W i think. I used it to power the 6x9's i think. and the second amp did the sub with the fronts running off the headunit. not great!

Anyway. I think i should just forget about that amp and buy a new one or two. what do i need? what kind of power and brand should i be looking at? my gut says get a kenwood, JBL, alpine as they are brand i know from before. anything new and well priced? maybe get a 4 channel amp with 4x50W rms for the front and rear speakers and a 2 channel to power the sub. maybe 100W bridged or something. any help appreciated.


Image

My build thread:
viewtopic.php?f=19&t=14083

mr.brown
Posts: 1267
Joined: Thu Apr 02, 2009 10:13 pm
fill in the right answer: 15
Location: Surrey

Re: amplifier help

Post by mr.brown » Fri Oct 21, 2016 6:11 pm

Most of everything I've ever read about and experienced personally in car hifi over nearly 30 years would tell you to remove the rear shelf, together with the 6x9s, and burn it. Then bury the ashes and sprinkle acid over the burial spot so nothing ever grows there. Also make a blood covenant never to mention them again.

Now that's dealt with...fit some 6x4s in the original rear side locations and here are my suggestions:

Option 1: Requires single RCA output from HU. Run front and rears from head unit and use a single amp (2-channel bridged or mono) for the sub.

Option 2: Requires two sets of RCAs. Run rears from head unit. Single 4-channel amp to run fronts with two outputs bridged output to sub.

Option 3: Requires 3 sets of RCAs: 4 channel amp for front/rear. Single amp for subwoofer.

Option 4: Requires 3 sets of RCAs. 5/6 channel amp. 2 channels front, 2 channels rear, 1/2 channels sub

I'm sure there are more configurations but fundamentally the rear speakers are there for "rear fill" only so don't really need to be amped.

On a separate but related note I have a brand new Kenwood Mono amp sat here that's no longer figuring in my plans :-)



User avatar
james butler
Posts: 2715
Joined: Fri Apr 24, 2009 1:54 pm
fill in the right answer: 10
Location: birmingham

Re: amplifier help

Post by james butler » Sat Oct 22, 2016 11:22 pm

im using 6x4 alpines all round powered by alpine head unit and inline alpine amp. i also have a picard pro plus sub in a custom box with 1500watt peak in phase amp.
this is more than enough for what i want but your needs may well be different to mine.


I dont mind project cars but I HATE SANDING!!!

steve bain
Posts: 628
Joined: Wed Apr 15, 2009 11:01 am

Re: amplifier help

Post by steve bain » Mon Oct 31, 2016 4:41 pm

so i have done a bit more digging in the garage and now have a better idea of what i have. as below:

For up front:
Impulse cm525 5.25" component speakers. 75W rms each at 4ohm
http://www.bassjunkies.com/car-audio-da ... ulse-cm525

for rear
Infinity 9603i 6x9's (but ignore these as not to upset mr.brown). I know they are not the best idea, but seems nuts to replace them with 6x4s when i already own them. can't i just tune them down a bit with the amp? if i didn't already have them i wouldn't bother.
http://www.sonicelectronix.com/item_261 ... akers.html

Rockford fosgate 12" Punch sub P312D2 - 100-500W rms - 2ohm stable
http://www.crutchfield.com/S-UHunNhaKDV ... 312D2.html

I have a JVC headunit with seperate RCA outputs for front, back and sub and i have run all 3 rca cablesinside so they are there. I have also run speaker cable back to the front from the boot to run the front from a amp.

I have also found 2 amps.
a pioneer gm-x334 4ch - 30W rms x4 (@4 ohm) or 70W rms x2 (@4 ohm)
http://www.pioneerelectronics.com/PUSA/ ... rs/GM-X334

XSA-720 4ch - 4x90W rms (@2 ohm i pressume) so probably 4x70W @ 4 ohm or something
http://www.mmacoustics.gr/shop/componen ... 3c02dd.jpg

so if i use the amps i have (despite looking ugly and being old) then i think i would use the pioneer bridged (2 x 70W rms) to run the front speakers (75W rms each). Then use the XS amp as a 3 channel. 1ch per 6x9 at 90W rms and the third bridged channel to run the sub @ 180W. I presume the pioneer should make better sound.

or buy this:

http://www.ebay.co.uk/itm/PIONEER-GM-D8 ... XQUmFSoL5c

which is slightly overpowered at 100W rms x ch to run front and rear speakers. and this to run the sub
http://www.ebay.co.uk/itm/Pioneer-GM-D8 ... xy3zNSoL5B

at 500W rms its at the max of the sub.

Problem is that will set me back around £250 which is a fair bit more than free for stuff i have in the garage.

I have no idea why i want to make the scirocco stereo so fancy, but most of it is already there and i own it already, so its just the amps i need to sort out really.


Image

My build thread:
viewtopic.php?f=19&t=14083

User avatar
Mr Funk
Posts: 2127
Joined: Wed Apr 01, 2009 6:39 pm

Re: amplifier help

Post by Mr Funk » Tue Nov 01, 2016 4:35 pm

I'll have a proper look when I'm home and see if I can remember my set up.

I'll echo Mr Brown though, burn the 6x9s.


Head of Complaints - Big Pie Cartel
If it sounds like it's naughty, it probably is.

steve bain
Posts: 628
Joined: Wed Apr 15, 2009 11:01 am

Re: amplifier help

Post by steve bain » Tue Nov 01, 2016 6:10 pm

ok. i will listen up. i still have the original parcel shelf so i will use that and get rid of the 6x9's. the more i think about it and reading i think i may get a 4ch amp (or use the one i have) and power the fronts off 2 channels and bridge the other two and sack off the rears, or just pop in 6x4's run off the headunit.


Image

My build thread:
viewtopic.php?f=19&t=14083

User avatar
Mr Funk
Posts: 2127
Joined: Wed Apr 01, 2009 6:39 pm

Re: amplifier help

Post by Mr Funk » Tue Nov 01, 2016 9:29 pm

Fat balls. Wrote a nice detailed post and it didn't appear to post. Feckin' phone.
In short: remount tweeters in the dash, you'll get much better sound quality and have each side on seperately channels.
6x4s are pointless if you have the components as far as I remember. The components are mids and tweeters so it'll sound odd behind you.
I had a similar set up and used a four channel - one channel per side and the sub was bridged. It was very clear and obscenely loud and clear when it needed to be.

Ask billy, he was "brave" enough to sit in mine and then Will's cars when we were drunk at the Nationals.


Head of Complaints - Big Pie Cartel
If it sounds like it's naughty, it probably is.

steve bain
Posts: 628
Joined: Wed Apr 15, 2009 11:01 am

Re: amplifier help

Post by steve bain » Wed Nov 02, 2016 9:54 am

thanks mate. decission made then. 4 channel amp, 1 channel per component in front and bridge 2 channels for sub. in that case i will probably buy that pioneer as it does look pretty! and relocate tweeters to dash. discretely somehow

thanks for everyones help. i think we have a plan.


Image

My build thread:
viewtopic.php?f=19&t=14083

User avatar
Mr Funk
Posts: 2127
Joined: Wed Apr 01, 2009 6:39 pm

Re: amplifier help

Post by Mr Funk » Wed Nov 02, 2016 4:32 pm

Mounting the tweeters is relatively simple.

There's a really good spot in the top of the dash if you're prepared to cut into it.

Will see if I can find the photos of where mine were mounted.


Head of Complaints - Big Pie Cartel
If it sounds like it's naughty, it probably is.

steve bain
Posts: 628
Joined: Wed Apr 15, 2009 11:01 am

Re: amplifier help

Post by steve bain » Wed Nov 02, 2016 4:53 pm

don't worry about the pic. there is no chance of me cutting my dash! they have little cylinders with a 45 degree on them so they may just rest nicely between dash and windscreen. maybe?


Image

My build thread:
viewtopic.php?f=19&t=14083

User avatar
Mr Funk
Posts: 2127
Joined: Wed Apr 01, 2009 6:39 pm

Re: amplifier help

Post by Mr Funk » Thu Nov 03, 2016 8:00 am

Could do but they'll be on display.
Recessed mine as I wanted it to look clean.


Head of Complaints - Big Pie Cartel
If it sounds like it's naughty, it probably is.

steve bain
Posts: 628
Joined: Wed Apr 15, 2009 11:01 am

Re: amplifier help

Post by steve bain » Thu Nov 03, 2016 12:36 pm

yeah i know. thats why i put them on the under trays originally. I might look at locating them inside the air vents....


Image

My build thread:
viewtopic.php?f=19&t=14083

User avatar
james butler
Posts: 2715
Joined: Fri Apr 24, 2009 1:54 pm
fill in the right answer: 10
Location: birmingham

Re: amplifier help

Post by james butler » Sun Jan 22, 2017 10:35 pm

another possibility is removing the mirror adjuster mech and fitting pods where the nobs were and putting the tweeters in there and run the cables through the hole where the mech went
i seriously cant remember the last time i had to adjust my mirrors so its a hole in the door cards you could make use of and can return it to stock if you dont like it no more.


I dont mind project cars but I HATE SANDING!!!