Big 12v amps |
Post Reply | Page <1234> |
Author | |||
studio45
Old Croc Joined: 16 October 2007 Location: United Kingdom Status: Offline Points: 3863 |
Post Options
Thanks(0)
|
||
Definitely scale back your power expectations! Especially if your source is a 110Ah lesiure batt. It will quickly become a very flat, unhappy battery if you ask it for anything like 1500 watts continuous.
All the big-power car amps are really designed to run with the engine on - so the bus voltage is about 14.4, often with extra high-power alternators to back it up. In addition to the high power consumption when running audio signal, they are not designed for low idle current, and will draw a few amps all the time, even when the audio output power is low. So your battery will still flatten quickly, even if you are only playing at a low level. If you have lots of money, you *could* look into lithium batteries. With those, sustained high power is less of a problem. The drone-racing boys have sorted that out quite well. But, it gets expensive REAL quick. Also, given that car audio is based around the nominal 12v battery, it can be difficult to get a fully-charged voltage your amp is happy with, that also allows the pack to drain all the way to 0% (either it will be too high when fully charged, or your amp will cut off before it is flat). DC-DC converters are something a lot of us use. These are boards that take in 11-24v DC (or an even wider range like 3-30v) and output a stabilised, usually higher DC voltage like 48v. This allows the use of different types of battery with your system, and keeps the voltage to the amp stable as the battery drains. However, they are only available in power ratings up to about 500 watts, so you can't really make a super high power rig with them.
|
|||
Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA
|
|||
valve head777
Old Croc Joined: 27 July 2012 Location: East Sussex Status: Offline Points: 1780 |
Post Options
Thanks(0)
|
||
Sorry more to add about batteries. The above calculation isn't taking into account the fact that the faster the amps are pulled from a battery, the LESS capacity it has. The nominal capacity of 110ah is at a 20h rate. This means 5amp load. The rate you are suggesting of 125+ amps will get nowhere near 45 mins and has the potential to distort the plates due to heat. The suggestion of 48v nominal is good because although 4x 12v batteries are used, the current demand is lower. It's high current that knackers electronics due to heat (and batteries). One more thing. The voltage drop under load must be taken into account. Large loads like above will see 10.5- 11v. There is good info to be had within the off grid, marine and camping communities on batteries ie correct sizing. It's all important because if you plane an 8 hour party, and run out after 3..........
Edited by valve head777 - 19 March 2019 at 7:44pm |
|||
Freedom of choice, choice of freedom.
|
|||
valve head777
Old Croc Joined: 27 July 2012 Location: East Sussex Status: Offline Points: 1780 |
Post Options
Thanks(0)
|
||
Dugadugaduga zap
|
|||
Freedom of choice, choice of freedom.
|
|||
JonB67
Young Croc Joined: 22 April 2016 Location: UK Status: Offline Points: 1376 |
Post Options
Thanks(0)
|
||
Is your sub bass reflex? Could look at how much it would cost to build a more efficient sub so you can get the output you want with less power and battery drain.
|
|||
Majestic
Young Croc Joined: 16 March 2011 Location: Glasgow Status: Offline Points: 1290 |
Post Options
Thanks(0)
|
||
Great advice guys, food for thought. Thank you all so much :)
|
|||
REIER
Registered User Joined: 30 January 2019 Status: Offline Points: 11 |
Post Options
Thanks(0)
|
||
I also believe it would be wise to aim a little smaller in regards to amp power. Think sensitivity, not amplifiers watts.
You need to have a sensitive system to make a portabel 12v rig work. This is of course because of the limited power available, so you need woofers that makes a lot of noise for small amount of watts. That fane 18XBs seems to be really sensitive, 99db 1w 1m in 8 ohms. You have 4 ohms, so probably even a little more sensitive. In the right cabinet, you will be suprised by the output with 300w. It will be enough for lots of people. As mentioned before, if your battery capacity is 110 ah on lead acid, that means you have max 50 ah available if you want the battery to last till next summer as well.
Average current drawn with for example pioneer gmd8604 is 4,4A in 4 ohms, so those 50AH will last about 11 hours. I firmly believe this is the best route. I used to have a hornsub setup with Pioneer GMD9601 that delivered 500 watts into two 8ohm speakers i paralell, so 250w each, and I rarely turned the volume all the way up, it was litererally more sound than I needed for most occasions. But you know, we all have different needs. What is enough for me might be just the start for you ;) But I really believe you would be surprised about how little it takes to fire up sensitive woofers =) Edited by REIER - 20 March 2019 at 11:31am |
|||
snowflake
Old Croc Joined: 29 December 2004 Location: Bristol Status: Offline Points: 3118 |
Post Options
Thanks(0)
|
||
been looking at a load of 4/5/6 channel amps. these look decent and can be configured to run bass plus two channels for mid/high Hertz HPD 4 Bassface DB4.5 Precision Power PC1000.5D Taramps TS 2000X4 Fusion SG-DA41400
The Taramps looks like the best spec. Not sure about importing from Brazil - think you just pay the VAT which would bring it up to ~£300 same as the others. just spotted an ex-demo Bassface for £165 on ebay which is half the price of any of the others new. there's two more left if anyone is looking. Edited by snowflake - 30 December 2020 at 6:14pm |
|||
snowflake
Old Croc Joined: 29 December 2004 Location: Bristol Status: Offline Points: 3118 |
Post Options
Thanks(0)
|
||
bassface amp arrived going into protect mode so it's been returned.
another Brazilian amp: http://bandaaudioparts.com/amplifiers/elite-line/elite-4000-4/ |
|||
Spanners5
Registered User Joined: 04 October 2017 Location: oxford Status: Offline Points: 184 |
Post Options
Thanks(0)
|
||
Valve head is right...... we have 6x 110 running 24 volt on our boat.....(plus 1x starter battery and 1x 110 for 12v fridge) you'll be shocked how quickly they need topping up. have used 130 battery's but isn't noticeably better.... just more expensive. also flattening the battery's ruins them big time. on our boat we try to keep voltage above 24.4 volts (12.2 volts if was running 12v ) ..... we def charge them if they get down to 24.2volts (12.1 for 12v) doing this makes the batterys live for YEARS longer. (i realise this is running a home not the odd party) try to stay away from low box batterys (less lead) also if poss try to get the ones you can top up the acid.
|
|||
I-shen Soundboy
Registered User Joined: 21 December 2016 Location: Big Smoke Status: Offline Points: 375 |
Post Options
Thanks(0)
|
||
Sorry to hear your bassface was junk.
I can personally recommend the Kenwood KAC-X1D monoblock. 600w rms into any load, very reliable. Most powerful kenwood ever made, (recent models not so). Ten year old now, and rare as unicorns, but pop up on the bay occasionally. Used one for mobile lithium rig, thumped away from 16.8v down to less than 11v. Faultless. The KAC-X4D was a.much rarer matching 4-way 150wrms (or 2x300w). I ran both on a 100A breaker and could trip with to much welly (amps were fused 60a each). I could get four or five loud hours from about 120 18650 lithium cells (about 25 laptops worth of cells).
Edited by I-shen Soundboy - 11 January 2021 at 11:12pm |
|||
Spanners5
Registered User Joined: 04 October 2017 Location: oxford Status: Offline Points: 184 |
Post Options
Thanks(0)
|
||
wow 16.8 volts! thats ace! the 6 volt battery's are supposed to be far superior than the usual 12v leisures too
|
|||
snowflake
Old Croc Joined: 29 December 2004 Location: Bristol Status: Offline Points: 3118 |
Post Options
Thanks(0)
|
||
I'm looking at four channel amps because they usually include seperate filter for each pair of channels, so can be used as a two-way crossover for bass and mid/high. saves on external crossover and load diversification should get the best out of the amp power supply. I have looked at some 24V amps made for trucks but the ones I have seem very expensive - less of a competitive market and lower volums. I have got a 48-60V amp module in the garage that I just ran straight of four batteries in series, but some of these car amps seem like better value. |
|||
Post Reply | Page <1234> |
Tweet |
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |