i.c.e in e34

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

   hi there,ive just installed a mmats amp and kenwood sub in my 34 and when i turn up the volume my lights dim badly and the car jumps to the bass? ive never had this problem with my other cars and was wondering if 1.the batterys dead or 2.the alternator cant keep up the requierd voltage.
the amp is a class d,1700 rms,subwoofer amp and reguires at least 100 amps and 14volts at full chat,so what do u guys think,new alternator?

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
518les Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 03-January-2005 Location: gloucetershire Status: Offline Points: 7	Topic: i.c.e in e34 Posted: 25-January-2005 at 16:38
	hi there,ive just installed a mmats amp and kenwood sub in my 34 and when i turn up the volume my lights dim badly and the car jumps to the bass? ive never had this problem with my other cars and was wondering if 1.the batterys dead or 2.the alternator cant keep up the requierd voltage. the amp is a class d,1700 rms,subwoofer amp and reguires at least 100 amps and 14volts at full chat,so what do u guys think,new alternator?

Sponsored Links

Badger 540 Members Profile Send Private Message Find Members Posts Add to Buddy List Really Senior Member I Joined: 23-October-2003 Location: West Midlands Status: Offline Points: 451	Posted: 25-January-2005 at 17:05
	What are you going to do with 1.7kW of amplification? I would think that you would need an additional battery, stiffening capacitor and a high output alternator , for example, off an auto V8 (140A) at the minimum................oh and some ear defenders !!! Andy
	Badger540 West Midlands

e34m5 Members Profile Send Private Message Find Members Posts Add to Buddy List Really Senior Member II Joined: 26-June-2003 Location: Near Rugby, Warwickshire Status: Offline Points: 1344	Posted: 26-January-2005 at 05:52
	Sounds like you need a nova not an E34 ...On a more serious note have you checked that you have got a good earth to the amp ?
	1991 525i Sport Manual

e34-520iSE Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Really Senior Member I Joined: 22-December-2003 Location: Gateshead, UK Status: Offline Points: 453	Posted: 26-January-2005 at 12:28
	ooo, you're trying to pull 100-130A for your sub amp, plus the power for your mids & HF speaker amp. which could be somewhere around 800 watts(60A ish peaks) to give some sort of balanced sound, PLUS the power that the car needs to function. As Badger540 & E34M5 says you would need a large stiffening capacitor and a second battery. A much larger output alternator would need some serious power cables to and from both batteries and you may find you have to work out a duty cycle to make sure nothing gets toasted. I would suggest limiting the amp's output until you can power it properly or it will just trip out or damage itself. I worked for nearly ten years in the audio industry and worked with some huge MOSFET amps and the ethos was 1 amplifier channel per speaker. Those amp racks would give out 30kW of noise and we too would have to sit and work out how much electricity we needed at maximum volume before we could turn anything on. Cheers, Shaun
	Self confessed madman 1990 Brilliantrot 2 ltr M20. Air force definition of explosives: A loud noise followed by the sudden going away of what was once there a second ago.

518les Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 03-January-2005 Location: gloucetershire Status: Offline Points: 7	Posted: 27-January-2005 at 16:14
	hi all,thanks for the input,im gonna lay down some 4 gauge wire to the amp with a 3 farad cap,im trying to get hold of my friend in the states so i can get hold of a quality spl sub,as im going to try and enter a few comptitions, e34-520iSE..hi there,the amp is a mmats dc300hc,its a serious bit of kit and very rare in england probaly 1 in 10,it has dual mosfet power supplys,and is class d,meaning its very efficent,and always runs cool,never gets hot like `named` brands.my friend who i bought it off said its a modified one which is close to 2000 watt rms and was in the states used in spl drag racing,he won several comps as he had two running 4 rockford 15`s,he tweaked it to 167.8 dbls in a gmc suburban! les

e34-520iSE Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Really Senior Member I Joined: 22-December-2003 Location: Gateshead, UK Status: Offline Points: 453	Posted: 28-January-2005 at 14:11
	Hi! I've just read a review of you amp, written by Brian Smith from the USA. Quote....... "This powerhouse is designed to push 1748 watts into a 2-ohm reactive load. The best thing about the D300HC is that you don�t need a train-load of batteries to power it. While it is capable of drawing around 180 amps at full output, most of that power is making it to your speakers as opposed to a max of about 50 percent seen in most other designs. On the down side, turn on/off noises (48.1 dB SPL, 44 dB SPL, respectively) and signal-to-noise measurements were a bit higher than usual (�86 dB) � but if you need 1700 watts, what�s a little pop? The amp also utilizes a protection circuit that limits current if you try to run it below its rated 2-ohm impedance" Sounds like a very good unit, putting all that power in a 2ohm load. Very efficient! I think you can buy separate anti thump relay kits that will stop the power-on thump tearing the cone. The other thing that would kill a speaker is if the amp output went DC. Do you get protection from that too? The red-hot voice coil ring looks great though.......! Best of luck with the install, & I hope you do well in competitions. Shaun
	Self confessed madman 1990 Brilliantrot 2 ltr M20. Air force definition of explosives: A loud noise followed by the sudden going away of what was once there a second ago.

518les Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 03-January-2005 Location: gloucetershire Status: Offline Points: 7	Posted: 29-January-2005 at 03:56
	e34-520iSE hi,ive never had a problem with the thump on start up.as for the dc current to the speakers,i havnt seen nothing go wrong yet,i currently have a kenwood tornado on there and that sounds excellent,but you cant turn it up no more than half way as the amp takes over and sub flex`s like nothing youve ever seen. ive seen a pioneer subwoofer in car audio direct for �109 and its a compition series,Key features TS-W121SPL Interlaced Glass Fibre/Carbon Fibre Reinforced IMPP cone Wide-roll, 3-layer fibre woven radial surround Double-stacked high power magnets Silver binding post terminal Aluminium die-cast basket with bottom hold structure Extended and vented pole yoke Dual 4 ohm voice coils (2 or 8 ohm) Features TS-W121SPL Frequency response 18 - 2.000 Hz Sensitivity (1W/1m) 89 dB QTS 0.328 Recommended sealed enclosure (Litres) 42.5 Lowest resonance frequency (FS) 32 Hz Maximum Power 2.000 Watt Nominal input power 750 Watt VAS 34.53 l Woofer size (cm) 30 cm Dual 4-ohm voice coils: 2 or 8 ohm What do u think,worth getting???? cheers les

e34-520iSE Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Really Senior Member I Joined: 22-December-2003 Location: Gateshead, UK Status: Offline Points: 453	Posted: 29-January-2005 at 12:08
	Hi Les, It does sound like a quality speaker. I am wondering if anyone else on the forum is using one. Maybe they could tell you of their experience with it. I bet it sounds great being able to run down to 32Hz! Can I show you a speaker we used in our systems? It's called a Fane Colossus http:// www.usspeaker.com/fane%20col18xb-1.htm We used a pair of them each side running at 3000W 2 ohms, and they really can shift some air! I remember washing my hair one day and drying it on the blast from the subs. Awesome, but probably irrelevant in the car world. It would just break the windows anyway......... Cheers, Shaun
	Self confessed madman 1990 Brilliantrot 2 ltr M20. Air force definition of explosives: A loud noise followed by the sudden going away of what was once there a second ago.