Sub setup

[MD13 459]

Hey I'm new to amps and subs but felt like having a go at adding some bass to my system so... I bought a sub and amp off trademe on the cheap to try it out. I picked up the following:

Pioneer TS-W2502D2/D4 sub in a box Specs

Lightning Audio FF150.2 amp

So having spent a number of hours on the weekend installing this (and surprisingly it did work) I have some questions.

1. Earthing - having the battery in the boot is very handy. Should I use the batteries earthing point for the amp? I haven't at present but was wanting to know if it would be better or not.

2. Main question - the sub details states 2 voice coils with the ability to connect in parallel or serial to produce either a 2ohm or 4ohm load... Or seperate channels entirely... Looking at the manual for the amp I shouldn't be trying to drive a 2ohm sub, but I don't know if I'm supposed to use both channels to power the sub or bridge to a serial connection or what. Or should I be looking at a mono amp (expensive)?

Some help on this would be greatly appreciated! Feel free to ask questions.

[_ethrty-Andy_ 2122]

Hey I'm new to amps and subs but felt like having a go at adding some bass to my system so... I bought a sub and amp off trademe on the cheap to try it out. I picked up the following:

Pioneer TS-W2502D2/D4 sub in a box Specs

Lightning Audio FF150.2 amp

So having spent a number of hours on the weekend installing this (and surprisingly it did work) I have some questions.

1. Earthing - having the battery in the boot is very handy. Should I use the batteries earthing point for the amp? I haven't at present but was wanting to know if it would be better or not.

2. Main question - the sub details states 2 voice coils with the ability to connect in parallel or serial to produce either a 2ohm or 4ohm load... Or seperate channels entirely... Looking at the manual for the amp I shouldn't be trying to drive a 2ohm sub, but I don't know if I'm supposed to use both channels to power the sub or bridge to a serial connection or what. Or should I be looking at a mono amp (expensive)?

Some help on this would be greatly appreciated! Feel free to ask questions.

In a competition setup you would have a common earthing point for all stereo components, but for ameture setup you can run straight to the battery will be fine

Connect the positive of one terrminal set on the sub to the negative of the other terminal set. Then connect the two remaining positive and negative terminals to the two terminals labeled bridge on the amp. Hopefully you havent blown out anything when playing around with it before!

[MD13 459]

I haven't blown anything yet - I don't think Had the gain turned right down for testing.

If I do as you have suggested what ohm load am I presenting to the amp?

Edited April 30, 2012 by MD13

[MD13 459]

Ok so i pulled the sub out to check the connection. Good news is that it's wired as Ethry_Andy instructed. Bad news (?) is that the model is different mentioned on the trademe ad. Its a Pioneer TS-W258D4 (specs)

so I believe that means my amp is seeing an 8ohm impediance... So that means lower power out right? Amp is rated at 150w RMS bridged to 4 ohm.

[_Matt_ 42]

This is what my wiring looks like. 2 channel amp to D4 sub.

copy that and you will be right.

although you will still only be sending 150w to your 350w sub which isn't ideal.

[Greg111 13]

I don't know too much about sounds, I have a 800w bridged amp powering an 800w sub.

The picture below shows a bridge type sub??

[MD13 459]

Matt my amp won't handle a 2 ohm impedance - wish it could... Yeah i think I'm sending even less than 150w at 8ohm. Figure my options are:

1. Sell the sub and buy a lower power single coil replacement.

2. Save and buy a mono 2ohm stable amp.

I'd prefer to do the second option but don't think I can afford that any time soon and won't look forward to replacing the 8 guage power and earth I just installed

Edited April 30, 2012 by MD13

[_Matt_ 42]

The pic shown is a bridged 2 channel, yes. (always read rms, that is the wattage that matters)

And to power a dual coil sub properly will cost, so I suggest getting a single coil if you dont wanna spend the money.

Edited April 30, 2012 by _Matt_

[_ethrty-Andy_ 2122]

Ok so i pulled the sub out to check the connection. Good news is that it's wired as Ethry_Andy instructed. Bad news (?) is that the model is different mentioned on the trademe ad. Its a Pioneer TS-W258D4 (specs)

so I believe that means my amp is seeing an 8ohm impediance... So that means lower power out right? Amp is rated at 150w RMS bridged to 4 ohm.

Yes your sub can be 8ohm if in series (as i instructed earlier) or 2ohm wired as Matt said. At 8ohms, you are getting half the power, at 2ohm you are getting twice the power (in theory, though your amp cant put out that much current and will probably die)

Matt my amp won't handle a 2 ohm impedance - wish it could... Yeah i think I'm sending even less than 150w at 8ohm. Figure my options are:

1. Sell the sub and buy a lower power single coil replacement.

2. Save and buy a mono 2ohm stable amp.

I'd prefer to do the second option but don't think I can afford that any time soon and won't look forward to replacing the 8 guage power and earth I just installed

Yes thats right, your only options. i wouldnt have used 8 Guage cable btw, thats very small for the current going through it, though you might be right for only 150W. i use 0 Gauge in my wagon

the other alternative is to just wire up one coil at 4ohm and leave the other coil connected to nothing, though that will make it quite inefficient id imagine. im not actually sure what would happen if you did that, but you wouldnt blow it up or anything, cant hurt to try. you *might* need to connect the two loose terminals on the same coil together as the other coil will act as an AC generator otherwise, but thats a physics lesson for another day. disclaimer, research this last paragraph first if you do this, i dont know the results having not done it before. works in my head though...

Edited April 30, 2012 by _Ethrty-Andy_

[Neal 512]

Matt my amp won't handle a 2 ohm impedance - wish it could... Yeah i think I'm sending even less than 150w at 8ohm. Figure my options are:

1. Sell the sub and buy a lower power single coil replacement.

2. Save and buy a mono 2ohm stable amp.

I'd prefer to do the second option but don't think I can afford that any time soon and won't look forward to replacing the 8 guage power and earth I just installed

Keep the sub and run it in series (8 ohm load) In reality there is not much difference in SPL between 100 rms verse 150 rms. If anything your give your amp an easier load to run and still should get reasonable bass volume.

Save up for a 2 ohm stable sub amp ( or some 2 channel amps will run 2 ohm load in bridge mode) look for at least 300 rms into 2 ohms.

Use your FF150.2 to power your front speakers later on.

In terms of running the earth to the battery verse to central point you will have no problem using the body as an earth with the power you are running.

However , if your running amps with 800 rms or more run the amp earths to the battery or consider the battery to chasis size earth cable. BMW's are fairly generous with battery earth size cable but you do need to consider what an additional (short term) 200 amps could do the the cable with high power audio systems. espically when starting the car with the stereo pumping.

[MD13 459]

Ethrty_Andy - think I saw a caution in the manual on running the amp to only coil... 0 Guage is huge! i can't imagine running enough current to require that - I was just wanting to add a little base. Checked the guide stickied at the top of this section and for the wattage I was intending to run 8 guage was sufficent. Though in hindsight I probably should have gone 4... Have you upgraded your Alternator/Generator with your setup?

Neil - cheers for the info. I had though about amping my front speakers, but at the moment I have a pretty average Panasonic headunit with only one set of pre outs. I definately want to replace that with something decent that looks a little more in keeping with the dash and with 2 pre outs etc. Also I have the fronts in the standard mounting position - in the front kick panels. Do you think it's really worth amping the fronts in those cramped little spaces?

[_ethrty-Andy_ 2122]

Ethrty_Andy - think I saw a caution in the manual on running the amp to only coil... 0 Guage is huge! i can't imagine running enough current to require that - I was just wanting to add a little base. Checked the guide stickied at the top of this section and for the wattage I was intending to run 8 guage was sufficent. Though in hindsight I probably should have gone 4... Have you upgraded your Alternator/Generator with your setup?

Neil - cheers for the info. I had though about amping my front speakers, but at the moment I have a pretty average Panasonic headunit with only one set of pre outs. I definately want to replace that with something decent that looks a little more in keeping with the dash and with 2 pre outs etc. Also I have the fronts in the standard mounting position - in the front kick panels. Do you think it's really worth amping the fronts in those cramped little spaces?

Not really much point amping your mids as you will find it just means you will have the volume on your headunit set lower than you otherwise would. really only usefull if you want to do competitions in your car which im guessing you dont, or you have it there just because you can.

I havent upgraded my alternator, and my setup has been in an M20 car, my setup being two 800W amps with a sub each and one 350W amp so well over 2000W when turned up. im sure if i drove around with it at defining volumes all the time i would though. I only have that setup because i like to know i can turn it up if the need arises, and got most of it out of cars i have wrecked over the years. In the real world, i have never turned it up that loud, i dont "cruise the town" lol

[jochen 4]

Ethrty_Andy - think I saw a caution in the manual on running the amp to only coil... 0 Guage is huge!

A 150W RMS load on a 12V battery is 12.5 Amps (Power / Voltage = Current)

And then allowing for whatever peak power your amp can provide... you may be doubling or trippling the current

E.g 3 x 12.5 Amps = 37.5 Amps

If you wish to run your stereo loud all the time, then you need to consider if your alternator has enough reserve capacity to power all electrical items and charge the battery, as well as power your sub amp.

PS: the body / chassis is a much bigger earth cable than you can ever fit. So earth the amp to the nearest, solid earthing point. It will be better than running an extra cable to the battery.

[MD13 459]

Cheers for the earthing info Jochen.

Next problem...

The headunit I have only has one remote out and it goes to the electric aerial. I wire tapped this line to provide the remote on for the amp. When I turn the ignition off I get a pop as the aerial goes down... Any ideas?

Edited May 1, 2012 by MD13

[MD13 459]

Bump.

I see this on Crutchfield - Link

Opinions?

[Greg111 13]

Aereial is blue and white, remote turn on is solid blue. Won't work correctly if not wired.........correctly.

[MD13 459]

Aereial is blue and white, remote turn on is solid blue. Won't work correctly if not wired.........correctly.

Didn't know that! I'll have another look... Been thinking about this and I don't think it had separate remote and antenna wires...

Edited May 2, 2012 by MD13

[Neal 512]

Neil - cheers for the info. I had though about amping my front speakers, but at the moment I have a pretty average Panasonic headunit with only one set of pre outs. I definately want to replace that with something decent that looks a little more in keeping with the dash and with 2 pre outs etc. Also I have the fronts in the standard mounting position - in the front kick panels. Do you think it's really worth amping the fronts in those cramped little spaces?

With a single pre-out you could run an RCA splitter and feed the ff150 & a latter sub amp. Run the rear fill speakers off the factory head unit. I ran a setup like this a while back on the wife’s car and it produced good sound.

If you’re going to the trouble of replacing the head unit look for 3 set pre-out version.(front / Rear / Sub) Possibly look at versions with built in time delay (some sony HU's for e.g) so you can offsite the driver’s side midbass & tweeter. This will give a stereo image that’s sounds more like sitting "middle stage" rather than "middle right stage"

You can get good sound out of factory e30 location for midbass drivers. As bass duties will be handled by the sub you don't need much of an enclosure size to produce midbass frequencies (80 hz up) .

Look at mounting tweeters on each side of the dash by the windshield to pull stereo image up.

The factory rear nokia speakers are ok for rear fill so don't worry about replacing those.

Alternator wise you should be fine with the amp you have. If you are doing lots of short trips in the winter with headlights, wipers, rear screen demister on than give your battery a chance to recover from starting the engine before driving around with bass heavy music. One of my e30 systems was around the 210 watt rms mark . When it was cranked you'd see a slight dimming of dash lights to the music but nothing really to worry about. I did however fit the highest capacity battery that would fix under the bonnet.

I only started having voltage issues (e36) at around the 600 rms point with a class A/B amp. The system could drain a battery in about 15 minutes if you were caught in traffic using low revs (not much alternator charging)

Ironically I had less issues when I change out the amp to multi amp 1000 rms total , The difference was run a class D sub amp which was far more electrically efficient.

That circuit looked fine for de-thump btw.

In terms of running the Sub with only one voice coil used , you can try without issue. I did this on an earlier system where the sub amp was 4 ohms min. I ended up running both voice coils in series as the bass seemed to be more controlled with better definition than just running one coil. No harm in trying different combinations.

[Neal 512]

hence me suggesting running amp in bridged mode with an 8 ohm load being better than running stereo mode running dual 4 ohm load.

3 pedals will be able to work this out when he has thought about this more deeply as most car amps run blt mode for bridging (hint, Think about the mono'd sine wave through a bridged amp sharing two power supplies and the recovery time needed to recharge the output stages of the bridge + amp and - amp under load)

8 ohm speaker load becomes the bonus for damping

[MD13 459]

I have bought a second amp of trademe - D class mono 600w RMS and 2 ohm stable. So the mission for this weekend is:

1. Upgrade power cables to 4 guage and double check earth connection (getting a little whine)

2. Replace 50A fuse

3. Wire DVC in parallel to result in 2 OHM impedience

4. Install new amp

5. Look at adding 'de thump' circuit to remote feed

Missing anything?

[Neal 512]

Now your talking !

6, Spanner check anything with bolts in and around the boot , check every few months (had bumper come loose once)

7, Check your rear fill speakers once you have the sub running. They may tear themselves apart with the energy of the sub

8, Take off numberplate and add double sided foam to back of plate. Then re-attach

You may not need item 5 with different amp

[MD13 459]

Cheers Neal - hadn't thought of checking for loose nuts and bolts :-)

3Pedals - take it easy fella. I think I said I'm new to this at the begining. Yes i paid for this stuff - but it wasn't expensive. Yes I'm going to try it at 2ohm - and if it does sound distorted I can always change it back to 8ohm.

Thanks again guys.

[Neal 512]

Theory of the amps is interesting,(built a few mosfet based hifi amps over the years and repaired too many to remember) yet much of car audio amps are geared towards high current output stages rather than using more voltage and running hgher impedance drivers. Even BMW have been dropping 2 ohm mid bass drivers in the cars over the last decade.

Doesn't pay to have online aurgments with 3 pedals as these are often very techincally sound( it's also easy to be taken out of context without writting a book rather than a quick post). But with car audio I've had 25 years of dropping sound systems into BMW's and a couple of SQ trophies to boot.

What I've learnt has been through a quite a number of systems , some have been gear towards lots of $$$ other have been mates with modest budgets. What I've found with Sub bass is the driver has the largest factor in the quality of sub bass and the amplifier is of less importance. However , power corrupts and in my experence I've been getting the better reaults with high power class D amps running low impendance drivers than I did with mid powered class A/B amps running higher impedance drivers worth a few $k with exotic onboard componets. Be assured that you are on the right track with what you are doing. Neal

PS , if anyone if after BMW size midbases I brought another pair of these recently. http://www.ebay.com/itm/PPI-355CS-PRECISIO...=item1c269ff104 These used to retail for around $1200 nz when they came out on the mid 2000's and still hold there own now.

[Neal 512]

Cheers Neal - hadn't thought of checking for loose nuts and bolts :-)

3Pedals - take it easy fella. I think I said I'm new to this at the begining. Yes i paid for this stuff - but it wasn't expensive. Yes I'm going to try it at 2ohm - and if it does sound distorted I can always change it back to 8ohm.

Thanks again guys.

Follow the youtube link and download the guy's mp3. It's a good track to check for rattles for the box and the car and tunning in the sub gains etc. Watch the volume though as at 600 rms you'll be pushing the DB's and don't want to run into clipping.

[MD13 459]

Picked up amp. Wired it up only to find it's DOA.