HISPL

High power amplifiers for 2.1ch stereo sytem.

33 posts in this topic

Hi Everyone!

I have worked in the car stereo industry for 10+ years but don't have as much experience with home hifi in 2ch or HT applications.

I am looking for a power amp to run my subwoofer, it is an RE Audio XXX 15 inch with dual 2 ohm coils.

I have no issues designing an enclosure for it, but finding a beefy 2kw+ mono amp or bridgeable stereo amp is what I will need assistance with as I'm not sure where to start.

Any reccomendations are welcome!

Cheers!

Adam aka HISPL

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I should add you'd want this to go with it - I think the two units have just become my new fantasy dump find of all time - might be looking through a lot of bins to find these two massive units (53kg and 15kg OMFG)

rotelrc5000s.jpg

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Thanks for the warm welcome :(

I like the old skool cool of that rotel amp and controler!

If I could find something like that I would jump all over it, keep the ideas comming if you can :)

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Hi Adam,

Welcome to SNA. 2kW+ power amplifier happy with driving either a 4 ohm load (the two voice coils in series) or 1 ohm load (the two voice coils in parallel). Don't want much do you? :(

To be honest, in the domestic hi-fi market the pickings are likely to be a bit slim, especially considering your two speaker wiring configuration options are fairly low impedance. Considering you want to use it as a sub only, perhaps there might be some offerings in the commercial / PA type market using Class D amplification to keep the cost of the amp to a realistic level.

Before anyone can offer any real advice I suppose it needs to be established just where you are heading with the project. If it's just very high SPLs at subwoofer frequencies you are chasing as distinct to tight, controlled and accurate bass response then the Class H type amp might be a possible solution. If you are after good fidelity then a good high powered Class A/B amp would most likely be the better option.

Here's a starting point http://www.biema.com/html/product/amplifiers/fw.htm a 3.8kW monster but not into 1 or 4 ohms. Use one channel into 4 ohms and get a tundering 1.9kW (hey that's pretty close to the 2kW mark you are looking for!)

Clearly such a low impedance load and high power are going to leave 99% of the valve amps off your shopping list, so some sort of SS amp is a logical choice. Also the other thing that needs to be taken into consideration is how much are you prepared to spend? For a good amplifier with a 2kW output, you really are looking at big bucks, but with a Mt. Pleasant address I guess that ain't too much of an issue? :)

Cheers,

Alan R.

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Hi Adam

The problem with pro power amps is finding an amp the does not have a fan for cooling. The noise level of the amp from the fan, if it's in the same room as the rest of the audio system as totally unacceptable. I have yet to locate a pro amp that does not have a fan apart from the Alesis which is not suitable for your requirements. When you manage to locate one please let me know.

Chris

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Adam, what you want is a pro amp that is stable with 2 ohm loads. Each channel driving one voice coil, or series wired for a 4 ohm load bridged. The cheapest amp that will do it is Behringer Europower 4000 with 2kw into each channel at 2 ohms or 4kw when bridged into 4.

Only thing is the fan.

Expect to pay many times the price for a "hifi" power amp with similar specs without gaining anything.

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Thanks for the advice folks!

I know it will be difficult (ie impossible LOL) but I want the woofer to be an alrounder if that makes sense.

I will use it for listening to stereo recordings mainly but with a little 5.1HT use to go with it.

I understand the limitations of tuning a woofer to suit HT LFE channels and the limitations of trying to use a woofer to handle both music and HT applications... however I feel that with plenty of power on tap and a woofer that is capable of sounding very good whilst handling this power I feel that I should be able to get reasonable results for both types of use.

The budget is tighter than you might expect Alan, I love living in Mt Pleasant but unfortunately I would most likely be one of its residents with the lowest savings account balance... LOL

I will look at the options that have been mentioned and do some homework on them, thank you for your assistance so far guys! If there are any other options out there please keep the reccomendations comming! :mad:

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Paul, thanks for the advice on the Pro Audio gear. I need to do some reseach on what might be available to that market. I'm looking at the Behringer lineup online as I type this.

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To do a fan mod to the Behringer amp is very easy and very effective. I could not hear any fan noise from the unit I once owned (EP4000). I posted a thread under a year ago with pics to show you how to replace the 24V fan (sorry, no time to search for it now).

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Might be wirth speaking to somone like Phil at VAF or call the Krix guys and have a chat- they use some poeweful gear at times and might know some tips on keeping costs down - eg Im thinking the Krix Cinema gear runs of some decent power amps?

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I'm thinking that unless that sub is incredibly insensitive, that you don't need 2kw for home hifi or lfe.

Got any T & S specs on it?

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Adam - this is what I call big - but its vintage and rare so not really any help - hope you enjoy the pciture though - welcome to SNA

http://www.thevintageknob.org/THEVAULT2/RB5000/RB5000.html

rotelrb5000s.jpg

Wow! This thing looks a whole lot like the Sumo 'The Power', designed and built by Jim Bongiorno in the US. I thnk I'll give him a call and ask. I wonder if Rotel licensed the design?

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Hi Adam,

Just wire the dual voice coil sub in series to get 4ohm load. To power a beast like that, club power amps (ie. biema, behringer etc) would be your best bet. Just mount it in another room so fan noise is dampened. Thats how my mate does it to power his PEAVEY club speakers in his house. Has the component rack in a different room to keep noise down.

I feel sorry for your neighbours! haha

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Rob, the driver is a very extreme one with low efficiency and extreme excursion (54mm ONE WAY!) and 2kw thermal power handling.

So I'd say 4kw of power is "just right" for it. The EP4000 will get the most out of it, although if the budget was a bit bigger I'd suggest a slightly more upmarket amp like Quest or QSC for driving into the low impedance.

If you find anything cheaper than the Behringer, it's almost certainly not worth using. The only new amps I've seen cheaper than Behringer were unknowns on ebay with inflated and unreliable power ratings. One was rated at 2500w and when I pressed for a correct rating they admitted it was really 250w.

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Hmmmmmmmmm wounder how much?

$100k which is a bit of a bargain to those fortunate enough to have that kind of cash for hi-fi.

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Rob, the driver is a very extreme one.

Would that be an understatement? :mad:

NFA

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Would that be an understatement? :mad:

NFA

Okay, was that shadows on the outer rubber suspension or was it creases and dimples I was seeing?

Cheers,

Alan R.

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Alan,

Every high excursion driver I've seen with a rubber surround become deformed when pushed that far. At around 100mm excursion how could they not?

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Jeez, I just did a quick sim with some specs found on the net, 85dB in-efficiency!

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Rob, you should have seen some of the TC sounds LMS drivers, which were quite a bit worse. I believe there is often some trade off of efficiency in order to firstly get more excursion, then to make BL linear over that excursion.

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