subs don't really need "high end" sound. many EXPENSIVE speakers have distortion levels of up to 20%! that's alot.
unless you want to wake the dead 24/7... the pyle should be adequate as a sub amp. i had considered one myself as my 30 year old radioshack integrated amp that i'm using has so much switch noise that often, i can't even get sound out of it until i scrub all of the switches (on/off/on/off) until i get sound again. it isn't a clean 75W either. my 25w (50w actual) NAD totally tightens of the bass and plays louder.
the pyle was designed for sound reinforcements and although it has a so-so 90dB S/N ratio, it should work fine giving you bass.
they're the cheapest power amps you can get if you shop around. (about $110) you can get a 100W reciever cheaper, but not one that you can "leave on" so that your reciever is the on/off switch. and cheap recievers tend to roll the bass off a little which is the opposite of what you want.
if you only intend to use the amp at reasonable levels, you should get by just fine. that pyles are rated into four ohms tells you they're reasonably rugged.
120W is quite good for realistic bass volumes. (i never break 1 watt myself LOL)
oops... i forgot to mention... look for the PYRAMID something 600 instead. it's the same exact amp under another brand label that's available cheaper. THAT is the "bargain" amp i was talking about. i think you can get one for $40-$50 cheaper.
budget minded... seeking exceptional values for 30 years and counting! LOL
oops, i was thinking of the PT-1200. the pyramid HA-600X (if i can read from my catague pic right) is the same exact amp.
looking at the 4000's specs, i see it's rated for 350W continuous. that's enough to rock a nightclub if you bridge it!
i'd say it's way more than you need (especially for the $600 price unless you already have one) and could get by with a lower power and cheaper pyramid unit, but i'm not into bass at all either.
now wait... by "house amp", do you mean "to be used in your house" or do you mean to be used in a night club or recording studio?
i might be leery of using it in a club setting where absolute reliability is a must. there are other makes of amplifiers eg. crown, hafler & QSC etc. available near $600 and that have established reputations for reliability.
i'd say if it's for home use, it's doable, but if you want equipment that's rugged and can stand up to abuse every day, spend a few dollars more on an amp that doesn't cut cost corners.
"in house" is a term used to describe professional installations. if you look at clubs and studios, you'll probably never see pyle mentioned.
an amp that blows up in the middle of a set could cost a nightclub MORE in a night's profits than the amp costs itself.
if you're looking for a sound system amp... look for bulletproof. i took it that you were just looking for a home unit.unless you listen to music 8 hours a day at full volume in your home... a home unit isn't going to take the same level of abuse that a pro unit will.
i'm not saying that the pyle unit is crap... i just wouldn't put my faith in it until it gets a proven track record like crown etc. ESPECIALLY when a touring company has 20 units pumping out 50,000 watts, you'd think they would want to save a few thousand dollars on amps, but they go with the more expensive lines because they're trustworthy.
hope this answers your question better now that i THINK that i know your intended use.
looking at the "musician's friend" catalogue that i just got, i saw QSC and crown amps that were rated for similar power outputs that were cheaper than $580 and that both had 3 year warranties.
if you shop around... i bet you could find them even cheaper elsewhere.