Help me choose from these amps I can get deals on

skydeaner

I am looking for pretty good sound Q and I need it to hold up to the ammount of power it says it will put out. Ok how about this... I have 1 polk db124 12" hooked up right now in about a .8? cu foot enclosure. I will be hooking up another one as soon as I get my other box done in a couple of weeks.

I want the amp I get to perform good now and after I get the other sub in, which of these would be best

Pioneer GM-7100M - 250 x 1 rms at 4 ohm, 360 x 1 rms 2 ohm
Directed Audio 750D - 275 x 1 rms 4 ohm, 400 x 1 rms 2 ohm
Alpine MRP-M350 - 200 x 1 rms at 4 ohm, 350 x 1 rms 2 ohm
Sony XMSD51X - 250 x 1 rms at 4 ohm, 500 x 1 rms 2 ohm

these are all right in my 100 dollar price range, let me know what you guys think, or if you know of any other amps in the ~$100 range that would be better to drive 1 of the db124's now and two of them later please let me know where I can pick one up.

Oh by the way, this is going to be going with a dx 6.5" component set I have up front powered off a kenwood excellon 75x2rms amp.

Jstas

Go with the Alpine amp. It's a solid performer and even though it is rated the lowest, it will most likely out perform everything else in the list. A second choice would be the Pioneer. The Sony isn't all that great and I've never heard of Directed Audio.

audiobliss

Alpine. Stay away from the Sony. I've never heard of Directed Audio, either. The Pioneer would be an acceptable amp if you had not mentioned the Alpine.

spwuinmk67

Directed is the company who, from what I can tell, owns Orion, PPI, Viper, etc...

MacLeod

Yup. Directed is DEI which owns a/d/s, Orion, PPI, Viper and a couple others. They make decent products but never were my favorite.

John's right, the Alpine is the best of the bunch. It was tested in PAS mag a while back and spat out over 400 watts at 2 ohms so you get more grunt than you pay for and since it only retails for $200 its the best mono amp for the money.

Id say the Directed 2nd and the Sony and Pioneer 3rd. They will both make their rated power and are built well enough but theyre nothing fancy. Alpine all the way baby!

cam5860

yeah I have had this Alpine mono amp for about a year and a half and it sounds great. A crutchfield rep told me the alpine v-power amps are the number one selling amps in the united states. He said they sell more alpine amps than any other brand.

MacLeod

Probably do.

Theyre built very well, make their rated power and are relatively cheap! That 50x2 amp for $110 is a gem!

PoweredByDodge

directed is a bunch of ****. period.

i vote the alpine. - unless you can get into an mtx mono 800w or a polk C500.1 for the same price, but i don't think you're gonna be able to - add my vote for the alpine.

1996blackmax

I would go with the Alpine as well. I've owned two of their amps in the past (MRV-T757, & an MRD-M501), both were great amps.

exalted512

alpine, directed, pioneer, sony
best to worst
-Cody

skydeaner

ok, thanks guys for all your help. I think I will go with the directed amps, just because I don't have very many people I know that own them. I like to be different and i want to blow people I know away with Polk and some other brand they have never used like directed. My friends know absolutely nothing about SQ and have always thought fosgate and alpine were the way to go on everything. So i can't wait to make their jaw drop over my all polk system with directed amps. Thanks again for the help

cam5860

Why in the hell do you want to go with a directed amp. If you want to be different there are a lot of better choices that people don't own than a directed amp. If you are going with a momo system why not go with the momo amps. I mean it's not everyday you see someone using polkmomo speakers in the first place. I mean people ask me everyday what is polkmomo because they see the stickers on my back window. Car domain runs specials on the momo amps pretty often i know on the 300x2 for 199.00. You would be a fool to buy a directed amp when you could own a momo amp for 200 bucks. Thats a steal for the power and sound quality a momo amp has to offer.

audiobliss

I would also suggest the Alpine or (preferably) the MOMO over the directed. However, if that's what you gotta have, you gotta have it.

But it's be superb with the MOMO amp and awesome with the Alpine.

PoweredByDodge

directed amps are very poor quality for SQ and just a **** build in general.

if i do recall correctly, they have a slew rate of 5 v / us, which is utterly abhorred.

mtx used to guarantee better than 20 v/us... and i'm sure most "good" manufacturers are in that range or better. zapco was what, 50 v / us?

damping factor on a directed amp is less than 50... ewwwwwwww.

zapco's up near 1,000.... i'm sure polk amps are in the 200 or better range... same goes for alpine.

directed is not the way to impress anyone. they're worse than fosgate dude. that's no lie.

MacLeod

True but you wont hear a difference.

If I shoot you in the face with a slingshot youll be pissed.
If I shoot you in the face with a BB gun you could be injured.
If I shoot you in the face with a .22 you will be severely injured possibly killed.
If I shoot you in the face with a .38 youll be dead.
If I shoot you in the face with a .44 youll be dead.
If I shoot you in the face with a .50 youll be dead.

Now each of these guns are better performers than the previous but are you any more dead with the .50 than with the .38?

Same with slew and damping. All amps made today will be good enough that you wont hear the difference between the 50 or 1000.

Like THD. .0003% is a whole lot better than .05% but it doesnt matter because you cant hear either of them!

audiobliss

There's a difference there, not matter how much YOU can't hear it.

And yes, there's a reason I made 'you' stand out like that...:D

MacLeod

So YOU could hear the difference between .05% and .00005% THD? Im impressed. I bet dog whistles drive you crazy!

neomagus00

as a matter of fact...

MacLeod

Then Ive got this set of $3000 cables you just have to buy! Wait til you hear how much wider they make your stage!

Mike B.

3K, is that all you got in intercommects? :rolleyes:
I used to run Apature 4+4 BL-4 "silver" rca's W/ compression ends.(~$150.00
a meter.)
Till I went optical.and Monster "minis" (the only thing that would fit in my mounting location.

Of the amps listed I'd do the Alpine, or buck up for the Momo.
Running the Momo 500.1 in the Jetta, and a Alp- MRVT757 in the golf.
As an installer , I'd like to play with a DEI amp w/ the bit writer feature so I could set it up, then "lock" the controls.

MacLeod

Anybody running $3000 in cables has way more dollars than sense.

I run Monster Standard cable at a stellar $.70 a foot. Zero noise, transparant signal and can withstand the elements. Thats all you need a cable to do.

Mike B.

Yes there is a steep dollar vs benifet curve after the $1-$5 ft cables. We used the silver cables only on mids/highs ,and only on good systems. I may have some bl4 left laying around, if you wanna try it . I'll look.

MacLeod

Sure. Id give them a listen for a while and send em back to ya. Never tried a $1000+ set of cables!

exalted512

I want to shoot someone in the head with a sling shot
-Cody

PoweredByDodge

regarding thd - anything under 0.5% i would say is acceptable and most likely not audible.

slew rate and damping however are not related to THD - THD is a byproduct of the amplification process. slew rate and damping are not by products, but rather characteristics of the quality of the materials and design of the amplifier.

**** slew rates and **** damping are not only audible in some cases but given the right circumstances can lead to driver fatigue / failure.

audiobliss

MacLeod wrote:

Then Ive got this set of $3000 cables you just have to buy! Wait til you hear how much wider they make your stage!

PM me your addy and I'll have a MO out pronto!!!

skydeaner

wow I wanna shot myself in the head with a slingshot... now has anyone listened to directed amps that isn't quite as particular about sound... how about this, will I be able to tell a difference between a directed amp and an alpine amp, or has anyone ever heard them head to head and noticed a difference?

ND13

Did Somebody say Alpine????

audiobliss

Never heard them head to head...'cause I've never even seen a Directed amp.

In all honesty, it's quite likely that you'll never know the difference between the Directed and the Alpine. However, due to specs and manufacturer reputation, I wouldn't even consider the Directed if an Alpine was available.

MacLeod

PoweredByDodge wrote:

slew rate and damping are not by products, but rather characteristics of the quality of the materials and design of the amplifier.

**** slew rates and **** damping are not only audible in some cases but given the right circumstances can lead to driver fatigue / failure.

Right, but my point is that even Jensen amps have damping and slew rates well above the level that would be audible.

Ive heard them both and there is nothing wrong with DEI. Both will easily make their rated power but the Alpine will be built a little better using better components.

Will the DEI suck? No but Id rather have the Alpine.

MacLeod

Just so ya dont think Im pulling this stuff outta my arse, here is an excerpt from an article Robert Zeff wrote:

I'd like to take this time to dispel another myth, that super high damping factors make an audible improvement. A damping factor of 50 means that the amplifier's actual output impedance divided into the load impedance is 50. In this example the amplifier's internal impedance is .08 ohms. A typical four ohm speaker typically has 3.2 ohms of internal DC resistance. So, the actual damping factor could not be better than 4/3.2 = 1.25! That is why emphasis on ultra high damping means nothing sonically.

(Robert Zeff started a little company known as Zapco which makes some of the finest amps on the planet, so I would say he qualifies as an expert)