Amp recomendation

[meinp5]

I have been throwing around the idea of trying to get myself a nice sound system in my car for a few weeks now. I also want to try make my own custom sub box using fiberglass. I have done audio installs many times so I am not a complete noob...I am trying to find a decent set of subs. I have also read on these boards that a $50 sub can sound better on a $300 amp than a $300 sub on a $50 amp.

My overall goal is to have a nice overall sound. I am not looking for 1000watts and thumping bass. The best way I can think to describe it is the way a nice home theater sounds. I like the presence of the bass, but I don't want it to become overwhelming.

This is the sub I am thinking about going with:

http://www.crutchfield.com/S-NMP3z8ZW0Cw/cgi-bin/prodview.asp?i=575P18S4&s=0&cc=01

$75 shipped for 2 isn't a bad deal at all. I have been told that Rockford makes a decent sub for the money.

Any suggestions for a good amp to match to these subs? Also, any suggestions on a better sub - in a similar price range let me know. I haven't made up my mind 100% yet.

Thanks,

Matt

 

[FoxPro5]

I have also read on these boards that a $50 sub can sound better on a $300 amp than a $300 sub on a $50 amp.

That statement is backwards, IMO.

What is your budget for an amp?

 

[meinp5]

I think the point is that the amp is what makes the speaker sound so good. I didn't say it, just seemed to be a common opinion.

I don't really have a set budget - last night I was looking at the JL 250/1 amp.

That statement is backwards, IMO.

What is your budget for an amp?

 

[THE Phen]

I think the point is that the amp is what makes the speaker sound so good. I didn't say it, just seemed to be a common opinion.

I don't really have a set budget - last night I was looking at the JL 250/1 amp.

I once heard a JL 13W7 in some guy's Navigator. Being sub notorious for sound quality, I was expecting great things from it. Turns out, he used all his available money on the sub and was running a crappy Jensen amp, or something like that to power it. It sounded so horrible.

If you're putting a dirty signal to a speaker, there's nothing the speaker can do but reproduce it as a dirty signal.

The JL 250/1 is a very nice sounding amp. I know a few people that have run them. I may get one myself...

 

[macklum]

for a sub amp I would go with a good quality class D mono block amp

 

[FoxPro5]

If you're putting a dirty signal to a speaker, there's nothing the speaker can do but reproduce it as a dirty signal.

Amps can induce distortion and I agree that you'd probably want to invest in some nice amp power if you bought a W7. However, if you play a clean, unclipped signal that measures the same from a Jensen amp or an Audison Thesis, you will not be able to hear the difference...especially on a sub.

The fact that a W7 on a Jensen amp sounded subjectively like s*** to you probably had more to do with the user than the amp itself.

THe JL 250/1 is a great amp, but your are power limited. The Slash series is also horribly inefficient. They do come with nice features such as a 1 band EQ with adjustable bandwidth.

Since you are running two single 4 ohm subs, you'd want to wire them in parallel to end up with a final 2 ohm load to show the amp. They are rated for 150 watts RMS, so your best bet would be to find an amp that will put out at least 300 watts RMS at 2 ohms (150 watts each).

 

[chuyler1]

The best thing to do is choose an amp and sub(s) at the same time so that you can budget accordingly. Take a look at the RMS output of the sub (in your case 2x150=300watts) and match it to an amp that puts out the same RMS power or sightly more (in your case 300-500w RMS).

Don't forget that impedence plays an important roll. I won't go into details but for subs you want to run the amp at the lowest impedence the amp can handle (usually 4ohms bridged for a 2-ch amp or 2ohms for a monoblock).

If the total price of subs and amp is above your budget, choose a lower priced amp and sub combo keeping in mind that you should always match RMS output.

Don't forget to budget for a wiring kit, LOC (if needed), and subwoofer box.

 

[meinp5]

Ok - so the 250/1 JL amp probably isn't the best bet? I'm not looking for booming sound...just enough for a nice clean sound. I would need something with a RMS between 300-500?

As for a box - i plan on making one out of particle board and fiberglass. I spent some time this morning reading your audio build thread and learned a few things and got some ideas. I just want to be sure before I order anything that i'm putting together some decent items that will get me the sound im looking for.

The best thing to do is choose an amp and sub(s) at the same time so that you can budget accordingly. Take a look at the RMS output of the sub (in your case 2x150=300watts) and match it to an amp that puts out the same RMS power or sightly more (in your case 300-500w RMS).

Don't forget that impedence plays an important roll. I won't go into details but for subs you want to run the amp at the lowest impedence the amp can handle (usually 4ohms bridged for a 2-ch amp or 2ohms for a monoblock).

If the total price of subs and amp is above your budget, choose a lower priced amp and sub combo keeping in mind that you should always match RMS output.

Don't forget to budget for a wiring kit, LOC (if needed), and subwoofer box.

 

[lisevolution]

Look into MTX amps for those Rockford subs... If my memory holds MTX is still owned by the same company as RF. They tend to overperform for the $ you pay and they prodcuce a nice clean signal. JL amps are very good, as are their speakers but you're not going to get much "value" out of them. They are some of the best on the market and you pay for it.

 

[chuyler1]

Anything from JL Audio is quality. A 250/1 could be considered on-par with most similarly priced 300-400w amps. You get 100% value from JL. Even though the price is high, you are making an investment and you will own that amp for as long as you like. MTX and RF are great brands too...but they fall a little short on the reliability area when compared with JL.

 

[THE Phen]

I've been running my JL 300/2 on the interior speakers in my Civic for around 3 years now. I bought it off a friend of mine that used it to run 2 Kicker Comp VRs. I know for a fact that he didn't pay any attention to the impedance of the subs because everytime he would run it, the impedance light would come on. Seriously, he thought that it meant that he was in teh safety zone. Thankfully he didn't try to turn it on more than 3 or 4 times. When i explained it to him, he no longer wanted it and I got it for a mere $250. It still sounds great.

I've used and abused alot of JL audio stuff, and I can honestly say I've never ruined any of it. For what you're doing with the 8's in the P5, and I know you're not looking for boom, but for SQ, I would personally go with the JL. Besides, if you decide to get different subs down the road, and they just happen to be different impedances, the JL will have the same 250Wrms output at any impedance between 1.5 and 4 ohms.

 

[meinp5]

Thanks for all the advise. Looks like I need to start getting parts. At this point I am going to pay the premium for the quality and go JL. Unless I find something that is a super deal on crutchfield or something...

 

[meinp5]

Went and looked at the memphis MCD250. I like the size of it and the look as well. I might end up with that too...hm...(uhm)​

 

[meinp5]

Well - I finally went for it. I ordered the Rockford 8" subs and the JL 250/1 amp. Now I need sound deading material and some wood. Then im going to build my box.

 

[chuyler1]

Look for MDF (medium density fiberboard) at your local home improvement store. Grab a kart...its heavy. 3/4" is ideal but with 8"s you can probably get by with 1/2" for some weight savings. Check Rockford Fosgate's website for recommended enclosure sizes and dimensions....or there may be instructions that come with the subs.

 

[meinp5]

Thanks...thats what I am thinking about doing. I want to give fiberglass a shot so I will build the base and rings out of mdf...then wrap it in fleece and load it with reisen.

My thought is to place the two subs in the back of the hatch by the rear seat. I would like to angle them towards the hatch and angle the amp and put it between the subs. That should leave enough room for my golf clubs.

Look for MDF (medium density fiberboard) at your local home improvement store. Grab a kart...its heavy. 3/4" is ideal but with 8"s you can probably get by with 1/2" for some weight savings. Check Rockford Fosgate's website for recommended enclosure sizes and dimensions....or there may be instructions that come with the subs.

 

[meinp5]

OK - I looked it up and it's recomended to use .25 cubic foot box. How exactly do you compute that...say I was going to make a simple square box...how big should that be?

 

[chuyler1]

http://www.carstereo.com/help/Articles.cfm?id=45

That should get you started, however you should never create a perfectly square box. It will promote standing waves inside which can affect the sound causing peaks and dips in the frequency response. Try to make a rectangle on one at the very least or an angled side if you have the right tools and skill.

 

[meinp5]

Thanks...i will check that out for sure. I wasn't plannign on making a square box...just trying to get an idea of aproximate size. I really want to do something with fiberglass though...

The subs are scheduled to be here Thursday...so I will start working then!

http://www.carstereo.com/help/Articles.cfm?id=45

That should get you started, however you should never create a perfectly square box. It will promote standing waves inside which can affect the sound causing peaks and dips in the frequency response. Try to make a rectangle on one at the very least or an angled side if you have the right tools and skill.

 

[lisevolution]

good luck with the box build and install. Fiberglass looks great when it's done right... make sure you wear long sleaves and pants as well as some thick gloves. The fibers you'll get from sanding down the fiberglass resin gets really itchy and annoying on your skin!