2) I was also very curious about why this amp is expensive because if u think about it, u can get 2 2100 for a little less than the 4150...well after i hooked it up, it answered my question..a friend of mine has the 2100 so i asked him to hook that up to my utopia and did a side by side comparison with the 4150..we both agreed that the 4150 sounds warmer and more detail and makes his 2100 sounded like it's dead..not to offend anyone with the 2100 because it's a very very good amp, but compare to the 4150 it's just isn't in the same league..it's the same company, i don't know why such dramatic difference..jason aka jason sizemore also compare the 4150 to the 2100 and said the same thing..u can email his for more details..even though the 4150 is rated at 75x4, i swear it sounds like it's 150x4..very powerful and very flexible crossover section..i also compared it to ADS PQ40 MCintosh mc431 and i found that the arc has a warm sound like ADS but more power..the mcintosh is a very nice sound amplifier with smooth response but not as much impact as the arc.-Troy 04-15-01

3) I have to agree with the perception the 4150 is a very powerful and clean amp. I have run a PPI 4100 and McIntosh MC440M on Dynaudio 340's with dual MW160s in the doors, mid/tweets in the kicks. The 4150 has more headroom, is very natural and smooth sounding, like it is not there at all, which is exactly what a great amp is supposed to do, it will stand up to any amp I have ever heard, period. At two ohm stereo for the midbasses I had to set the gains to zero! How many systems have that problem, talk about fast/tight drum hits, whew! The mids/tweets were on the other half through custom passive crossovers, very crisp and clear. I recently installed a pair of Rainbow Refs and dual 6.5 Pros. Incredible is the only thing I can say! One 4150, three large midbasses, two tweeters, hugh passive crossovers and just flat out kick in the seat midbass, super tight and such real mids and tweets, never heard anything like it. I will be installing an Arc 2100 for the pros this week, another great amp, the Refs get the 4150 all to themselves. Would use another 4150 for the pros but just could not make it fit in the install. The 4150 is one very fine amp indeed. -Rick 05-15-01

4) Hey guys, I figured since I've had a good deal of listening time on Jason's 4150, rainbows, and 250L's i'd throw in a few words on the amp too. First off I'd have to say for sure that the amp puts out a fair amount more than 300 watts on the pair of bridged channels. The bridged channels really seem to drive the 3 10's rather well. I'm 100% sure the 10's could handle more power, but the amount they are getting from the amp is still rather stunning once you have a listen. Now on the components I honestly figured that they would lose some output when Jason went from the 2100 to the 4150 since the 2100 is rated with a bit more power, but once again it seemed like they gained a bit more output. They seem to stay controlled a bit better at really high levels. As a whole the amp does a great job of running the entire system. It's definetly up there at the top of my "list of amps for next system". I guess that's about all I can really say about the amp since I'm no great audiophile or anything, but I figured nevertheless I'd try to be somewhat helpful. If you get the chance and the amp fits your needs go for it. I don't see how anyone could be disappointed in it. -Shane 02-26-01

5) I got to listen to this amp for 4 days at CES. Demotrios was running a 4 inch prof. comp. set and 2 IDQ 8's. Due to ambient noise, the amp had to be pushed fairly hard to compete witht the surroundings. This amp performed flawlessly over the four day period (basically 10 hours per/day straight). Not one problem. I did not get to compare the 4150 directly to the 2100, but I assure you it has all the power you need. If I did not have 2 2100's already I would definately be using this amp to power my front end. Once I finish my home theater project I plan on switching out the 2100's for the 4150. I need to make room for a 2050 to run my rears (I will be adding DVD with dolby digital/dts). -Rich 02-28-01

6) My system consists of a Cdx-c90, Arc 4150, Arc 2500, Focal Tn51’s, Focal 8" Utopia mids, Orion Hcca passive xover, and a Cmp 12. I used to have a Mcintosh MC222 powering my fronts and an alpine 50x2 for the rears. When I had this setup, the sound was very open and detailed, but the one thing I didn’t like about it was that the treble can get harsh when pushed loud. I mean really push loud. I wanted to try something different so I bought an Arc 2100 to try out. When I hooked that up, the most noticeable difference was that the top end got rounded off, the harshness went away, but at the loss of a little detail. The midbass also sounded clearer and had more punch to it than the Mcintosh, but the difference was slight. The arc 2100 also played louder than the Mcintosh, even though both were rated at 110x2 rms. I was content for a while, but I read that the 4150 is a much better amp and I got tempted to try it out. When I ended up getting one, replacing the 2100, and the alpine. At first, I was thinking, how good can this 75x4 be, I mean it is only 75x4 watts after all, how could it sound better than a 100x2??? Well that was before I hooked it up to my system. After putting it in, the sound of my fronts was a perfect blend of Mcintosh detail and Arc smoothness. The highs were soft, yet detailed, and mids were very engaging and smooth. The midbass was incredibly strong and tight. With the arc 2100 and the Mcintosh 222, I had to turn up the gains on both amps up a lil to get to the level that I wanted them to be at. With this Arc 4150, I had them set at 0 and it can get louder than I want it to be for most songs. I moved the gains up like 1/5 of the way, but ended up turning them back down to 0 cuz it got too loud. Now, this might not be the case for everyone’s system, but my point is that this amp sounded louder than the two other amps that were rated higher and with gains turned up. I also hooked this amp up to a Shiva using the rear channels bridged. For comparison, I hooked up an older model Sony 2100G which is 100x2 or 380x1@ 4ohms, the Arc is rated at 320x1 @ 4ohms. I compared the sound of the two and the 2 were very hard to distinguish from each other, both had nice and controlled bass, but the Arc’s gains were at 0 and the Sony’s gains had to be set to3/4 to match the output of the Arc. This Arc easily competes against amps that are rated well over 100watts. Overall, this amp one of the best I’ve owned. I find myself more involved with the music after putting this amp in, instead of being analytical all the time with my components. If you ever get a chance to listen to one, I suggest you do, a great combination of power and smoothness. -Leon Shing

7) Having heard so much about this amp from Jason and others, I decided to purchase one for myself to accompany my new front stage plans. I scraped together the hefty sum and days later I had a 4150 in my hands. Almost identical to the 2500 cosmetically, I soon realized that this amp is something special on the inside. After a good deal of experience with the amp, I'm prepared to say that it is worth every penny of its MSRP.

My first experience with the 4150 was rather brief; my friend Glen stopped by my house for 20 minutes or so having just mounted the baffles and his Dynaudio MD 160s to the bases of his kicks. ID NX-30's from his Chameleons still in the doors, and the MD160s in the to-be kicks, we gave the amp a try. Despite the unfocused soundstage and relatively high volume of the tweeters (we hadn't even wrapped towels around the MD160s yet) the 4150 drove the MDs quite effortlessly, and the NX-30s blared relentlessly. Admittedly, my first experience with the amp was by no means lengthy, but I was not overly impressed by the amp, especially compared to other ARC amps I had used in the past. It was comparable, yes, but certainly wasn't the overwhelming surprise I had been convinced to expect (Jason.) I was somewhat underwhelmed, but was not quick to judge the amp based on such minimal experience.
The following day, it was proven that I had been wise to withhold my judgments. Glen brought the car back by, having wrapped towels around the baffles; the drivers were much happier and therefore more adequately displayed the abilities of the amplifier. We went through several CDs, all the while adjusting the angles of the kicks, and of course listening. At times, I was forced to lean back and admire the sound. The MD160s displayed no signs of receiving anything other than clean power from the amp. In my experience, they like plenty of it, and the 4150 did not leave them under-powered (note that the driver's RMS rating is twice the rated output of the 4150.) The musical reproduction was incredibly dynamic, suggesting beyond-adequate headroom especially during not only strident vocal passages and horn solos (see Steely Dan - Dr. Wu, Dire Straits - Your Latest Trick, and Miles Davis' album Kind of Blue) but also during bursts at lower frequencies (The Philadelphia Experiment - The Miles Hit). Equally remarkable was the precision of reproduction of rapid guitar notes and higher frequency drums (The Roots - Mellow My Man, Datskat, and Essaywhuman?!!!??!). It is also quite notable that all this was presented with an incredible degree of warmth; the sound of the amp is a bit more sonically pleasant than that of the 2050 of 2100. The 4150 did not seem noticeably less powerful than the 2100, and exhibited an overwhelmingly superior degree of headroom. I was quite pleased.

So the 4150 passed the lightweight test with flying colors; what about more demanding loads? We installed the Dynaudio MD100s in place of the NX-30s and used ID x-4 crossovers I had laying around for the time being. We installed an IDQ 12" (DVC 2 ohm) on the front channel (the sub channel on the 4150) and gave it a listen. The amp was not at all hesitant to drive the sub to its limits, surprising as I've seen an IDQ take much power. Running the entire system, the amp was more than adequate. I still don't consider this setup to be horribly demanding; Jason can tell you more about the amp under heavier loads.
Realizing that I could get only minimal use out of Glen's system, I decided it was about time to throw my own front stage in my car. This consists of a pair of Oz Audio 200ls, a pair of Dynaudio MD140/2s and a pair of Dynaudio MD100s. I built passive crossovers (with some email support from Rick a.k.a. RAAM Audio) for the Dynaudios, to be run off the two rear channels, and I am running the 200ls off the front channels. I was absolutely blown away by the clarity and warmth of reproduction when I first auditioned my setup, not to mention the output. I have been a lover of loud music since I was old enough to remember, but this setup definitely has the ability to be too loud for my tastes. After some work on the angles this evening, the amp's precision, clarity, warmth, and sheer power have become even more obvious.

So I've described a number of setups which proves an important point I have yet to address. This amp is extremely flexible. Crossover options, different modes, etc... allow for almost any configuration one can dream up for a 4-channel amp with no added hardware. I'm extremely pleased with the amp for this and other reasons. Ask me how much power my amp puts out, and I won't have a clue what to tell you, but be assured 75x4 will be nowhere in my response. I had high expectations for this amp, as I have grown to expect much from ARC, but I have been utterly blown away by its performance-Ryan 6-28-01

8)First Thoughts

The first thing I noticed about this amp was it's length and the great paint job. It measures 16.5" and the glossy royal blue paint coat makes the amp stand out, almost as if it was chrome. Well, the length and the paintjob is not why you are reading this review so I will continue.

Install 1

I have heard many amps from Audiobank(Not Bahn) to Zapco and so far nothing comes close to the Arc Audio 4150. No, it is not the "perfect" amp, but it comes damn close. I used the amp to bi-amp my Dynaudio component set(4ohm). I ran the 1" MD100 Soft dome tweeters and 7" MW160 Midrange/bass off the front and rear channels respectively. The first thing I noticed when I installed was that my gains were turn all the way down and I was still receiving a good amount of output from this amp. I had never been satisfied with the amount of output from any amp when the gains were anywhere close to all the way down. The built in xover were the average 12dB highpass / lowpass w/24dB option 55Hz - 550Hz on the front channels and 12dB highpass /lowpass w/x10 switch 55Hz - 5.5kHz on the rear channels. The xover was well built and did its job. The only thing not average about this xover system was the full, high and low xovers switches for both channels which are located on the bottom plate of the amp. Arc Audio calls them "set & forget" xover switches, I find "forget to set" more accurate. Every time I finished rewiring my system, I had forgotten to change the "forget to set" switches.

Install 2

I began to get tired of driving around with no subs, come on, after a while we all miss our bass. I didn't have another amp to use so I decided to run my Dynaudio component set off the rear channels and run 1 12" IDQ V.2, in a custom built ported enclosure, off the front channels. I ran one channel to each voice coil at 2ohms and set the amp up in sum mono mode (both the signal on the right and left channels of the amp are the same). This was the entire system in my car for a period of 2 months and I was completely
satisfied.

I have no way of testing the actual power rating of the amp but I can assure you from listening to it and many others that it wasputting out way more than what it was rated. The bass control came in handy in this install, now that I had a sub. The amp was great as a "whole system" amp, and the rated "150x2"(bs)@2ohms powered that IDQ sub with no problems. For this install I decided to set the gains right away, but the output level with gains turn down was still quite a bit.

Overall

I fell in love with the amp. I enjoyed driving around with no subs just listening to my components play. The sound of the amp was crystal clear and very warm. It's hard to explain a "warm" sound but if you have ever listened to good high-end equipment you probably understand what I mean. My previous Esx Quantum Series amp was great sounding but when compared to the sound of my Arc nothing has come close, yet! All I have to say is this is a wonderful amp sq amp. It's price is way above most amps but well worth it. I would buy an Arc Audio amp any day. I give this amp a 9 out of 10 (always something to be improved). This is a very goodrating considering that the only other amp to come close was a Sound Stream Rubicon model getting a 6/10/01 .-Glen Carty
The trick to car audio is buying stuff you will never have to replace.