# updated small review of the pdx 4.150



## zfactor (Oct 19, 2005)

well i had the guy that bought mine come in today with them...i happen to also have a audison vrx 4.300 here as well...and these are some of my thoughts after comparing the 2 today. his system consists of the jl audio zr series (not the best but it gave me a good idea of the differences between them..), the pioneer deh-880prs hu and the pdx 1000 on a alpine type x sub in a ported enclosure he had built before coming here... 

i used a good mix of music, from various artists... these includes rebecca pidgeon, tori amos, godsmack, lords of acid, limp bizkit, prince, donald fagen, and mary chapin carpenter. i had others but these were the first that came to mind for what i wanted to listen for and tracks i know well... 

first since it was in the car i used the alpine pdx 4.150 and pdx 1000. i turned off the 1000 for the sound quality listening first then added it later. 

one of the defining characters imo of the pdx is the amount of shimmer and air it has. also has better staging and imaging off the bat than the vrx did which is saying a LOT..the staging was def higher and more centered this was with no tuning so im shure the vrx could sound the same. the higher octaves were super impressive with no sibliance or harshness (other than what i would consider normal for the zr comp set the tweeters tend to be semi-bright to my ears which in fact the pdx did a decent job of taking some of this away which impressed me) the lower octaves by itself still sounded kinda dry if you will. they did have authority but def not up to the audisons level. they were def very clean and i can def describe the pdx as being detailed VERY detailed.. tori amos can sound kind of mixed up or jumbled together on certain systems; on her crucify album i could hear everything.. nothing got garbled together things seemed almost more "real" where i could here the bass separate from the guitars and vocals it wasnt so jumbled.... the audison performed equally well but didnt have this same character.. it did sound superb but things seemed to be more cluttered sounding sorta very hard trait to describe..the x-over in the audsion blows the pdx away (this one has the modules installed) the alpine being only a 12 db x-over and the markings didnt seem like they were right on numbers wise. i found myself going lower on the dial than what it was marked to obtain what i thought was the right frequency for the comp set...did a good job but it could use some work and i think they should check their markings on the amp.

the alpine ran out of steam before the vrx did though..the audison just seemed to have more in reserve than the pdx and clipping was less noticable on the audison. the pdx imo got plenty loud for just about anyone especially if running this thing active... more power than just about any tweeter could need or want. 

now the audison was def a warmer sounding amp. the pdx kinda reminded me of the "american" amp type of sound, well what i call it anyway. the audison had that european amp sound which i actually really like. not so in your face as the pdx. the pdx kinda screamed at you where the audison was more "relaxed" sounding i guess i can call it more dynamic. the pdx reminded me of the older usa built amps in a way... old school rockford or others similar... the midrange on the alpine imo was not as good as the vrx. it was def great and pretty close to the vrx but didnt have that same impact.. sounded sorta softer and a little more hollow.. the audison def had a much faster attack and more impact to the lower octaves, much more authority here. the pdx was absolutly no slouch though.. and just lacking on the lowest of octaves which some may not even care about if using a sub. now the audison was def a more "refined" sounding amp...had more of an articualte type of sound. 

the pdx ran HOT VERY HOT... never shut off though. in 2 hours of listening overall it was def prob almost to hot to handle i let it cool before swapping to the audison amp. we had not thermal issues at all though... impressive for how hot it was overall.. i guess they did a great job of thermal transfer to the actual heat sink (the body and sides of the aluminum parts of the shell) otherwise i fear this thing would have melted down. but the audison DWARFS the alpine size wise when installed in the car!!!!!!! we could put 2 of the 4.150's side by side where only 1 vrx would fit.. this alone adds tons of value to the pdx imo...

imo the audison would be my first choice here though due mainly to the fact i feel it would do better for all out sq purposes and i like a warmer sounding amps myself. i do think im going to give the alpine a chance though. i did like the upper end of the pdx more than the audison in this case though which was suprising to me. the audison i can say is a cleaner amp and had more backbone to it.. but i guess how much can be asked from an amp this size at these power ratings. i ordered one to play with when it gets here. both amps are of the highest quality from that brand though.. and i do have to give credit where its due for a alpine amp (i say this because i have never been a fan of alpine amps) it performed very well, i listened to these before but didnt really "listen" and sit down for a real audition. i kinda installed them and found the problems i didnt like and took em out. i am usually like that one thing will turn me off and i will not use it... maybe to picky i guess..



i do have to say when added the 1.1000 actually popped its fuses once on us. he said this was the second time the amp did this. im gonna call alpine tech tomm and see if they have heard this before. just not sure why this would happen other than the amp drawing more current than the 80 amps of fusing can supply.. maybe larger fuses are in order ill ask their tech dept... one thing about the 1.1000 is i do not feel it "sounds" like it does rated power. def weaker on the sub than many other amps i have heard rated for less power.. not shure why?? i replaced it with a jbl bpx1100 that was a cust unit we had here just for testing and the bpx killed it output wise. take it for what its worth but i dont know if ill be using the 1000 for my sub amps or not yet.. seems id need 2 at least to do what i want, and these are not cheap...

hope this helps ill post more the more i listen to the 4.150...


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## 300Z (Mar 20, 2005)

small?   

Leo


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## zfactor (Oct 19, 2005)

lol i could have poss gone over each track i used???


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## dual700 (Mar 6, 2005)

Great review!
Now, when are you gonna buy my VRX.6 Direct?


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## zfactor (Oct 19, 2005)

lol wish i had that much $$ right now for just the one amp... i was trying to get up that much for that one but id still have to go buy the sub amp as well...


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## zfactor (Oct 19, 2005)

okay after spending a week with this amp..

well i like it and i dont.. lets elaborate that shall we.....

i LOVE THE MINIMAL current consumption i mean wowowowowowow, i even put this one on my bench to test it and hooked it up to the monster 90 amp power supply we have here and that thing didnt even flinch.. i mean the amp meter didnt even hardly move with all 4 channels connected. the amp is just so efficient. i HAVE NOT YET once had the amp shut down on me. it gets super hot. but never thermalled on me not even a quick turn off... great in that respect. sounds very smooth and dare i say warm. one other thing i love is the speaker connectors. i hate the concept but love the fact it doesnt matter which way you plug them in they are always "right" as long as you put the wire into the connector the right way. i think alpine could have made them only fit in one way but at least this way there is no fumbling with them when they are installed into the tight spaces they are made for just plug them in and go...also only 2 allen keys needed. a large one does power ground and the upper mounting plates, the small one does everything else. i prefer one size but 2 is better than 3-4 different ones i would have guessed with all the connection and stacking options these have

now the upper end is very realistic but seems sorta "thin" not sure how else to describe it.. i replaced a pg ti amp in my car with this one and the pg just was more robust i guess i want to say in the upper section. i didnt notice till doing a few a/b comparisons. the amp sounds really very nautral though. cymbals are set back and not screaming in your face but sound so "real". now i did not have the same effect i had in the other setup with the low end this time so i am wondering if that is system dependant more now. although on the test bench it sounded this way so not quite sure yet what to think there. im thinking its just the type of sound these class d's will produce. overall so far i am happy with it. i do not think its in the league of the arc se or vrx though. for what they go for on ebay i would def say a awsome amp. but i for one dont think id be paying retail for these.. up in that range for not much more you can get a top class amp and really not spend a whole lot more. i would be switching back my vrx's i have if the 1.500 sub amp would actually handle a 1ohm load and not shut off on me the whole time i was using it.. 

so overall i am pleased i can HIGHLY RECC these for a stock electrical system. wowowowow the power these put out for the current they draw and their size alone makes them a HUGE contender in the amp market. i have three of them in a "stack" and they really take up next to no room at all i find that amazing. the 1.1000 seems a little lacking for a amp we tested at just over 1100 watts. it just doesnt sound like 1100 watts for some reason. it does in fact out out the power though. im looking more into that now and talking with alpine tech tomm to see what they think. it does a great job though. again very strong for its size. if there are any other issues or finding ill post them up...


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