powering 4 rev8's on a budget, amp advice

[nautiques4life]

Currently I have 4 wetsounds Rev8's on my tower being powered by the original stock tower amp (I think it is the Polk 400.4?) Anyways I believe it is a little under powered, with black Friday/cyber Monday coming up I'm considering upgrading but I really don't know what I should be shopping for. Not looking to spend a ton of money, but any specific amp suggestions or even just a general range of specs that I should be looking for would be great... Thanks in advance

[MLA]

A 2 chnl is going to be your best bang for the buck in terms or output in a single chassis to drive 4 pods. Its going to take a serious increase in wattage to make an audible difference. An extra 25-30 watts rms wont cut it. Hard to beat the output and build quality of an Arc KS300.2 for driving 2 pair. Or even better, the marine Syn-2 from Wet Sounds.

[swatguy]

Budget and powering 4 Rev 8's are really not two words you can use in same sentence. You need power and a lot of it. Good power isn't cheap. The Rev's are rated at 200watts RMS each, but really liven up at 300rms.

You're going to want to find a 2 channel amp that in 2ohm mode comes as close to that as possible. The Revs definitely can handle more. Mike is the expert. I am just a boat owner with a stereo. I personally think even that ARC KS300.2 and Syn 2 option are way under powered for (4) Rev 8's. You're only going to be seeing 300wats RMS which is going to be halved going into to (2) speakers. That at optimal levels is only 150 per speaker which in essence isn't much over your current setup. You wouldn't be getting your $$ worth in my opinion. I would be looking at the Arc KS 600.2. It's just gonna be hard finding amps with the power rating you need for a true "budget" amp to match those 4 top end speakers. The KS600.2 is about the cheapest solution without going to two amps.

If you wanted to go on a budget and run a (2)amp solution you could do it that way also. You could just bridge your current Polk and run (2) Rev 8's off it. Then add a 2nd Polk and do the same. This would be the most cost effective way to get you the power you need. It would leave you 400watts to each Rev 8. Overkill yes, but you can tune it down. Running your amps more conservatively is way better for the amp than making it scream.

[MLA]

If the OP wanted to drop the "budget" from his post, then absolutely consider the Wet Sounds SD-2 or Arc KS600.2 and even toss in the JL HD750/1. Not as much wattage as the two 2 chnls, but its regulated so its output wont change across its operating voltage.

Both the Syn-2 and KS300.2 would be a 40% increase. With only 2 pods, 175W is on the light side, but with 4 pods at 175W rms each, thats respectable.

Adding a 2nd 4000.4 is certainly a way to increase the wattage overall. Down side is, it means installing a whole other amp install. Factor in the labor time and incidentals needed and it may not be all that budget. Especially when retail is $390 (yes, likely found cheaper from an internet clearing site).

[Jason Skerlong]

Check out the JL 800 x 8 channel http://www.jlaudio.com/xd800-8v2-car...plifiers-98259

I am running this to power 4 rev 8's and it sounds great! I bridged them to get 200w rms at 4 ohms per channel which the revs need.

[MLA]

Actually, all 8 chnls are @ 2 ohm on the 8 chnl bridged to 4 chnl mode. At that price point, the HD750/1 or the Arc KS600.2 are far better choices. Both allow summed mono and the KS600.2 is 50% more wattage.

[Msajecki]

The challenge with most amps is current draw. ARC has some that are designed for low current draw applications, not sure of those amps suggested are. If you're looking for an amazing power per $ / power per size / power per current draw, you can't beat this: http://www.kenwood.com/usa/car/amplifiers/kac-m3004/

It can be had for under $150, does over 350 watts per channel in 2 channel bridged mode and only draws a maximum of 22amps. It's super small and is conformal coated for marine applications.

Here's a link to a test on it, showing it truly exceeding max power rating: http://youtu.be/99tiyWuuAGM

All things being equal, power is power.

[MLA]

To start with, JL, Wet Sounds and Arc have all lead the way with supper efficient amps, and everyone else fallowed suite. All the WS, JL and Arc amps listed are either Class-D or G/H. Both are very efficient as compared to older class-A/B, which some are still clinging to.

in RE to that kenwood m3004. Hate to say it, but its RMS in 2 chnl mode is only 150W watts not 350. At that figure, I would be surprised if it did ever draw more than 22A in current.

Since the OP has 4 pods, this amp would not work for him in 2 chnl bridge mode. This amp is stable only down to 4 ohm in bridge mode and 2 ohm in 4 chnl stereo. The only way to make this amp work, would be to run it in 4 chnl stereo, which would net 50W rms to each pod. Thats 75W rms less than his current amp is delivering.

The OP could go with two and run each in 2 chnl mode for 150W rms to each. Thats only 25W more then present. but yet its a $300+ investment plus the space needed for a 2nd amp. The Syn-2 and KS300.2 are way better choice still, for only a little more investment.

[Msajecki]

Did you look at the review video? It shows it running 2ohm loads in 2 channel mode. I tested one myself in a car for about a week, driving it very hard in 2 channel mode, 2ohm per channel, never once got it to shut off. AND, never blowing the 30amp fuse, therefore, never drawing more than 30 amps of current.

Yes, if the budget is there, go with the more expensive amps. I was just pointing out a viable, cost effective, reliable, space saving, low current drawing alternative.

[MLA]

Not being a Kenwood engineer, I can only go by their published info. What I see through the link you posted, is an amp that is not stable below 2 ohm p/chnl stereo or 4 ohm bridged. This means you can only bridge a 4 ohm or high impedance speaker. Two 4 ohm rev-8 can only be wired to a 2 ohm load or an 8 ohm load. 2 ohm bridged wont work, again based on kenwood's published specs, and 8 ohm bridged = 4 ohm stereo output of 50W rms.A single 4 ohm Rev-8 would only net 150W rms. Again, this is based on whats published. Its not uncommon for amps to bench out above the stated CEA-2006 RMS, but i dont bank on those. Much more accurate to make comparisons by sticking to the standardized CEA test results. Having a higher birth cert is just a bonus.

You as an owner are free to drive the amp with whatever load you choose to, its just not a recommendation im going to make. I will watch the video and fallow up with more thoughts after watching it.

[MLA]

In RE to the video, one question for Msajecki. Do you drive your cars at the engines RPM redline all the time? This is basically what that amp tester did. Just keep in mind though, he did it for only a few seconds. The tester clearly stated KW rates this amp as no less than 2 ohm stereo and 4 ohm bridged. he took it down to 1 ohm stereo (2 ohm bridged) just to make the amp put out its max possible wattage, just to see what it would do. You cannot in any way, use that 3 second dynamic test, as a bench mark for running a system in the real world. A quality amp will likely not like the low impedance and go into protect mode. A price point amp may just run till it lets the smoke out.

[Msajecki]

You should do some research about the tester they use before making an assumption that it's a dynamic output test.

I've got 27+ years in the AV business. I have designed, engineered and installed many, many competition winning audio systems and have made a great living in this industry. Although I have the knowledge to go toe to toe with just about any engineer about PRACTICAL applications of 12v amplifiers, I use simple methods to make recommendations, I TEST IT, in a real world application, with music, driving speakers. Most specs come from marketing departments and sales planners, not technical departments. I know this, I've lived this.

I'll type it again, all things being equal, power is power. An amplifier is not supposed to have a sound, it's purpose is to be neutral. It should not color the sound. It should amplify it.

There absolutely was a time when there were a few good amplifier brands out there, and most everything else was fair at best. Today, things are much, much, much different. The differences between most amplifiers from reputable manufacturers, built with similar technology, with similar BOM (build of materials) Have negligible differences at best.

Take any brand name 4x50 watt 4 channel amp, with similar design (Class D, Class A/B) at similar price points with similar current draw and you will get similar results.

For instance, a 4x50 watt JL Amp at $599 MSRP won't play any louder than a JL Amp at $299 MSRP driving the same load, unless for some reason they under rate the $599 amplifier.

Pay a little more for a more rugged design, features, better conformal coating, better warranty, etc. and it's worth it. Paying way more for similar features will not perform magic...there is physics involved here folks....it's called Ohms Law, not Ohms Theory.

Good quality, reputable brand, low distortion, efficient power supply, good corrosion resistance, great power to size ratio are the attributes to look for when choosing an amplifier for your boat. Subtle differences in sound quality will have minimal application....IN A BOAT.

Back to the original question, what budget amp he should use? any reputable brand amplifier that has conformal coating, has good power to size ratio, has an efficient power supply and a great warranty. Alpine, Kenwood, Rockford, JL, PowerBass, Memphis, Pioneer all make good amps. There are hundreds of other brands out there too. Plan to spend $200 and you'll do great. $300 is even better. Spend more, and we need to get into discussions about voltage, wiring, speaker efficiency, impedance curves, etc.

Find a LOCAL, REPUTABLE 12v specialist (car or marine) and buy something from them. Avoid online if you can, local experts are always better if you can find one.

Have fun, turn it up, enjoy the music.....it's not rocket science.

[MLA]

Well, ive watched the clip a 2nd time. At the 6:44 mark, the tester states he going to do a dynamic run. He goes on to reiterate that the amp is not rated for a 2 ohm bridged load. He even states that the 2 ohm bridged dynamic run "should hurt the amp". Ive made no assumptions.

I do agree that many specs come from marketing departments, such as the "600" printed on the box of the very amp we are discussing. Real world, that amp will never deliver 600W. Its a 300W rms amp that benches out with a little more.

[Msajecki]

Then, I stated that I TESTED IT MYSELF FOR A WEEK, in 2 channel, 2 ohm load.

Your analogy of running your car at redline is not accurate. Music is dynamic and impedance is frequency dependent. I realize the test is a DYNAMIC test. And, I realize that MOST companies rate their max power with DYNAMIC tests.

You'll also note from the video that they test RMS power, with music, and show that it makes way more than the rated 25 watts per channel.

NOMINAL impedance applies to the usable frequency range. So, unless you have the impedance curve of the speakers you're driving (which is rarely provided) and you're playing test tones, it's a guideline, not a rule (assuming the amplifier doesn't have low impedance protection).

I'm really not trying to get into a pissing contest. Not at all my intention, and I hope it's not coming off that way.

Pointing out a great value amplifier for the original question....that's all.

[MLA]

No pissing match at all, I just happen to totally 100% disagree with this amp being a viable option for the OP, as you intend for it to be used.

Yes music is dynamic. Placing a load on the amp thats below its intended nominal impedance, has the amp running at peak output, as in red lined, right? Since the actual speaker impedance will change with the music, it will certainly dip even lower then nominal 1 ohm x 4 you've placed on it. This is exactly why an amp has a minimum impedance per chnl.

Low impedance cutoff or not, I dont want to drive my amp to that point.Why would I want my amp to cut out during the best part of the guitar solo? So I can raise by beer and say "its meant to do that"?