nsxdemon

So I've been reading up on some background on the stock deck and it seems like it can't really deliver a good amount of power. I wanted to buy a set of Infinity speakers for my 2002 MP5 and just swap out the stock speakers (so a pair of 5x7 Kappas and a pair of 6.5s). They're around 90 or 91 dB sensitive, so that's a start but I'm wondering if I'll be able to notice an appreciable difference in sound quality and loudness if I use a 4-chan amp to power the speakers. At least that way I'll definitely have clean power going to them.
So if I change the stock speakers with Infinity Kappas and I power them with the stock HU, will I lose some quality over powering them with a decent 4-chan amp (say the JL Audio 300/4)?

Also, the HU doesn't change if I add the in-dash CD changer right? Since it's a modular design, I don't think that the power handling will increase, but I might be wrong.

Thanks guys,
nsx

Dave Cameron

You are a quick study -good for you!
You have several issues going-
You will not get "good output" from the paper cone speakers no matter how you drive them, stock headunit of outboard amp.

The headunit, does not have much in the way of output power no matter what speakers you own, no matter how efficient.

The solutions are as you surmize two fold- replace the speakers with better built ones, and amp them in some fashion.

Everyone has their own path to heaven, but my path of choice would be

First Step- audition new speakers, and replace the old. You may not have all the amp you need, but you will get to hear your tunes on speakers you at least like the sound of.


Second Step- if you do not have enough volume for your liking with the new speakers, then amp it! The 300/4 is a very good amp for the dollars, very good technology and clean sound.
With ten times the power that a JL would produce you could blow the speakers if you are not careful, but I can also promise you this- the distortion of underamping them will also blow speakers for you, and more speakers have died of lower power distortion than higher power.
Also check into JBL amps, a very good amp at an excellent price, and the JBL will take speaker level input-

Which brings up the third area- the stock headunit is a good platform. Unless you are driven by a love of some features, or a desire to play with gadgets (thats me!) it can run your system just fine if the amp and speakers are well chosen.
No the six changer will not add any power to the system, many of us wish! The headunit is cool becuase it is modular, but Mazda dealers hike the price of the units so high it is totally unreasonable. That alone will drive many to aftermaket audio in a Protege. For the price of that 6 disc unit in my area, I could get speakers and an amp and probably a decent six pack for the install!

Also keep in mind that while six changer units are cool because of the ease of use factor for us lazy types, the single disc stacker normally has better sound characteristics to it. My two cents would be stick to the single play unless you are lazier than me (which I would find impossible to beleve) and just have to have the six, and use that money on speakers and an amp.

nsxdemon

So basically you're suggesting that I should go buy the speakers I'm comfortable with (probably the Infinity's, even tho some JL Audio speakers are very nice too) and install them first. If at that point I'm not happy with the sound/loudness/whatever, then amp 'em with either the JL Audio or a JBL amp. And basically leave the changer alone cuz not having to change CDs manually isn't worth the money for a changer.
Thanks Dave, at least now I've got a good idea of what I should do.

nsxdemon

Yea I understood that...but the thing is that I'm not 100% sure about the power specs on the stock HU (I've seen a couple of different quotes, so I can't say for sure since I haven't checked out the specs on the HU's back). Well the Infinity Kappa 5x7s take 100W RMS and the 6.5s take 75W RMS. So yea, they're pretty high-powered speakers, and my hunch is that they'll need an amp, but I just wanna make sure.

Infinity Kappa 5x7
http://www.infinitysystems.com/carau...er=KAP&Cat=MEL

Infinity Kappa 6.5
http://www.infinitysystems.com/carau...er=KAP&Cat=MEL

nsxdemon

Ehhh....great, so now I'm gonna start paying more attention to the whole "Where to Mount an Amp" threads that have been around here. I guess that most speakers I had in mind would need an amp to power them. The JL Audio XRs need similar power even though they have a higher efficiency, but even the cheaper Infinity Reference series speakers need 60W RMS, so yea, I'm outta luck with the stock unit. Oh well, amp it is then.
Thanks for the help guys,
nsx

Dave Cameron

Hied40 is correct you will almost certainly end up with an amp I would imagine.
And you both picked up on a point that is not undersood or brought up enough- underamping kills more speakers than overamping.
NSXdemon- ( A friend of mine is really into NSX by the way, has three of them) The stock deck rates out on my bench at about 8 watts no distortion, and about 12.75 watts with 3% (considered the threshold of audable distortion, most people hear it earlier than this) distortion. Not a lot of power, but it would move the infinity's for you until you have the bread for an amp. The JL and JBL are suggestions, there are many brands out there, I have had positive results with both of these and recommend them on a regular basis. Blaupunkt, nakamichi, PPI, entry level Phoenix, are all good amps. I like the JL so much I use it in my Protege!
You may not need the amp if you like the sound of the speakers, and do not normally listen at higher levels. If you do like higher levels, then an amp will most likely be an automatic.
By the way, most headunits have at best only so so amplification. Even decks that say "high powered" may only have 15-25 watts. On headunit amps or any amp for that matter, keep an eye on the distortion at the rated level. Distorton levels of .003 or so will reflect the ture wattage. Some REALLY sneeky vendors will mix the ratings, tell you 22 watts but show a distortion number they got at 6 watts. Read real close, and stick to name brand hardware and you will be fine.
Check back on the boards, folks here will always be happy to help out- folks like Hieb40, hihoslva, onehawaiian, Blue LEDz, and sunbyrne are all very good people willing to help out.
Any decent shops or chains in lewisville?

hihoslva

Underpowering speakers can mean death to them - but I think it's important to understand why. It took me while to understand, but knowing this stuff helped me from wasting even more money on bad audio decisions .

First - simply underpowering speakers is not truly what destroys them - what DOES is sending a "clipped" signal to them.

Most people who crank up a stereo (any stereo) and hear the speakers distorting immediately think the speakers suck, and can't handle the power they are getting. This is usually untrue - the distortion is coming from the AMPLIFIER - be it an outboard amp, or the internal amp in the head unit. When an amplifier is driven into distortion, the signal it sends to the speakers is amazingly damaging. The details involve lots of physics, and I don't understand enough of it (yet) to explain it well - but the "clipped" signal pushes the speakers beyond their physical limits, even at low power. This is why so many newbies (which we ALL were at some point, and I think I still am in many respects) blow up expensive speakers and can never figure out why - "if the speaker runs 100 watts RMS, why did my wimpy 20 watt RMS deck fry them?" Distortion, distortion, distortion.

So if you wanted to buy those Infinity's, and skip the amp for now, you will be fine as long as you don't overrun the DECK. Keep the volume **** in check, keep the distortion out of the signal (you can hear it), and those speakers will last forever, underpowered or not.

However, to get the sound they are designed for, you will need to power them properly with an amplifier.

Great sounding speakers don't need to cost a lot of money or handle a lot of power just to be good. The best bet is always to match the speaker power to the amplifier power, and don't distort - keep the volume reasonable, and a low power system can sound 100 times better than some 1000 watt systems. But if you want more volume, along with clear sound and no distortion, amplifiers and speakers to match the power are an absolute must.

And the golden rule is - if it sounds good to YOU, then it sounds good. Listening to some excellent systems can help you out, but in the end, it's YOUR money and YOUR car, and YOUR ears are the only ones that matter.

~HH

hihoslva

If you were dmaging your speakers, you'd know it. If you play them loud enough to sound bad, they won't last long. Sounds like you are not doing that, however - good for you! I don't know if I would have so much restraint . But maybe that's why I'm on my third subwoofer, third and fourth amps, and third set of front door speakers. Hehe.

If you really like to "reward" yourself, safely do without the amp for a while longer - it'll be like foreplay. Then when you finally get a nice amp hooked up, and finally hear those speakers sing - BOOM! Audio orgasm.

Anyway - your speakers should be fine when you finally decide to amp them. Just take care of them for now, and they'll perform just like they should when they get the power they crave.

~HH

Dave Cameron

Hihoslva- you are of course dead on and right, the root of all evil in either instance is distortion and clipping of signals.
It makes for one of the more tricky issues of bass. Most bass amps and speaker are as a matter of course run at amazing distortion rates. If the distortion is part of the expected operation, then it is blown speakers waiting to happen. Or french fried amps.
Digitial Design here in town sponsers several folks locally. We have shared many an evening in the shop as they pull the spiders off blown up speakers, pull the coils and then rebuild them. They are casualities of the Bass wars.
Clipping and distortion on either end, too much or too little, can be a terminal thing.
Also you are right on about matching up amps and speakers, just need to make sure which numbers are the "real" numbers, as marketing hacks love to post peak output or max distortion numbers for advertising.
There really needs to be some meaningul standards for audio specifications.

hihoslva

There are some standards - it's called the "Big Book of Whatever Sells Tons of Stuff".

Of course, accurate rating for amps and speakers are key. But sticking with reputable brands can usually solve that problem easily enough. If they sell it at WalMart - don't buy it.

hihoslva

Well - good morning.

I would be wary of buying this amp. Two reasone - one is legit, the other is just my own opinion, with possible facts thrown in. I'll explain.

First, if your components are rated for 50 watts RMS, you don't want to give them 150% of that power. Yes, they can probably take it, but for how long? I can justify: I had an Infinity Perfect 10 sub, which handles 350 watts RMS, 1400 peak. I hooked up a 500+ watt amp to it, figuring I'd be more than safe - a little "extra" - but nowhere near peak power. Here's the result:


Shredded. Too much CONTINUOUS power. Thermal breakdown.

Bottom line - match the RMS to within a few watts. A 50 watt per channel amp should be easy to find.

Second point is that I'm not too sure about those power ratings for the Blau amp. Granted, I have never used one - but my gut tells me something is a little "off": As a general rule, when impedance (ohms) presented to the amp are halved, the power is doubled. In addition, a 4 ohm bridged mono load should have the same power specs as a stereo load @ 2ohms per channel. So, using this "rule of thumb" - that amps should either put out 50w x 2 @ 2 ohms/channel, and 100w x 1 @ 4 ohms mono, or 75 w x 2 @ 2 ohms/channel and 150w x 1 @ 4 ohms mono. I could be totally wrong about this, and the power could somehow be regulated to the specs you listed - but those numbers just don't add up. Just makes me wonder why not - is the power regulated somehow, or are some of those numbers due to over- or underrating.

Maybe someone with more Blau experience can answer that. But the amp is a bit too powerful fo your components anyway. Consider something that puts out 50 watts/channel @ 4 ohms/channel. And, see if you can find a brand that typically underrates the amp's power. Many makers will tell you that an amp makes 50 watts @ 4 ohms/channel - but not every amp puts out 50 CLEAN, UNDISTORTED watts. If that 50 watts is with "all channels driven to full power" etc. - that usually means a distored signal and *poof* for your speakers. I can only give an example based on my equipment - I have a Rockford Fosgate 360.2 powering my front stage - the amp is rated to put out 360 watts @ 4 ohms mono - thus the name. The ACTUAL output is 539 watts, with all channels driven FULL power. (this info is from the bench tst sheet included with every RF amp). Now, that's not really 539 useable watts, because the amp is driven into distortion. BUT - the 360 watts (and then some) are definitely useable, and I am getting the power I paid for. A company like Jensen might list this amp as a 550 watt amp - meaning it might make 550 watts just before it blew up. See the difference?

The more equipment you add into the equation of your system - the more complicated it gets, and the more things you need to consider. And just rememebr - sticking to "all one brand" (Blau, anyone? ) is useless for amps and stuff. Yes, there are compatibility issue with, say - changers and decks - you want to stay within one brand there. But for everything else, only do it if you feel the desire to. It will not enhance your performance, and matching the brand of amp the the brand of deck means nothing.

~HH

hihoslva

Precisely. And just because a company makes good head unit, doesn't mean they make good amps, speakers, etc.

I know I will get slammed for this, but I have to say it: Pioneer makes some great decks. Many people use them, and are very satisfied with them. But I think you'd be hard-pressed to find many people running a schweet Pioneer or Pioneer Premier head unit, and running Pioneer amps, or Pioneer subs or speakers. For decks, Pioneer does a great job these days - but for amps, subs, etc. - not that they'd be poor components by any means, but there are better choices, and you can get more for your money.

I don't know about the Blau amps - but my OPINION (with no real facts to back it up, mind you) is that they may be decent, but you could get more for your money with something like a JBL or a whole host of other brands - Try to audition them - and get your hands on some real facts about power. I know that the JBLs and Fosgate amps are underrated - meaning you WILL get the power you think you are paying for. There are other brands, too - I jut don't know any off the top of my head.

Just a note about brand "loyalty" from someone who used to be a Kenwood freak - until I saw the light.

hihoslva

Rockfords are solid amps - some people knock them because the older models used to be "better" - maybe that's true, but I'm running two RF's (and own a third) and have had nothing but positive results with them.

I run a 360.2 and a 500s - both bench tested at over 500 watts each in max ouput.

I would expect that the sheet for the 200s would read around 250 watts max output - meaning you'll get the 50 watts per side clean and distortion-free.

Check out eBay, as well as www.IkeSound.com for good prices on RF amps. Ike's is a very good place to order from - NO shipping charges, friendly people, and reasonably fast ship times. They advertise on eBay, too - as "Scalal1" I think - but the prices are the same (well, the prices are less, but they charge the shipping- works out to the same price as ordering direct).

~HH

hihoslva

Cable running is easy in our cars. Most people have run the cable through the passenger side firewall - along side the main wiring from the ECU - just poke a hole in the grommet.

If you are planning on adding any other amps later on, consider using 4 gauge wire. If not, 8 gauge will do just fine. I ordered wire from www.knukonceptz.com - good wire, good prices, and quick shipping.

Wire is wire, so don't get caught up in brand names and stuff. The more strands, the better - and knukonceptz is good, flexible stuff.

Also - don't go crazy with speaker wire either - remember that you will be tapping into the factory speaker wire, figure behind the deck. So getting anything fancy, or thicker than stock - is not necessary. 16 gauge is usually cheap, and you can get it anywhere.

Use decent RCA cables - no need for the best and most expensive, but don't use the real cheap thin crappy ones - they pose the chance of allowing noise into your system. Measure the distance, and get the shortest wires that'll work - no need for a big bundle of tied up wire because you bought 20' RCAs.

Make the ground wire as short as possible from the amp, and the same gauge as the power wire. If the amp is under the seat, use one of the seat rail mounting bolts - that should keep you under 6", which is awesome. Make sure it is touching bare metal - scrape away any paint if necessary.

I'm not sure what size fuse is recommended for that amp, but use a good waterproof fuse holder on the power wire, not more than 18" from the battery. The "barrel" type fuses are great, and you should be able to find a decent fuse holder for a few bucks at Circiuit City or someplace like that - even KnuKonceptz has this kind of stuff, too.

You should try to keep the RCA's as far away from the power wire as possible. Since my amps are in the hatch, I ran the RCAs on one side of the car, and the power down the other. With an amp under the seat, this really isn't the easiest thing to do. Just keep the wires from touching one another wherever possible. If they must come close, try to put something between them and tie it all together, so that they are kept apart. If you wind up with a "whine" in your system that gets higher/louder when the engine revs, it's usually either the RCAs picking up noise from the power wire, or a poor ground connection. Keep those two factors in check and you should do fine - but the ground is more important - the RCA/power wire proximity is, too - but don't make yourself crazy over it. Worry about it IF you get noise, and leave it alone if you don't.

Oh, and a GREAT alernative to "mounting" the amp under the seat with screws - buy a big piece of velcro, and use the "hook" half (the rougher stuff) on the botom of the amp - then when you put the amp under the seat, it'll stick like glue to the carpet without having to either screw it into the floor or have a loose amp flopping around.

Any other questions, just ask. Take your time, and it's a simple process. Oh - remember NOT to install the fuse in the holder by the battery untill all your connections are made. No need to shock yourself silly (unless you like that kind of thing).

~HH

DaleK

Hey guys,

I just read over this thread (one of the better audio ones we have come up with I think!), and I had one thing to add about amp specs - you are correct that as impedance halves, power should double. However.....this depends on the power supply. Is it regulated or not? If the power supply is regulated, not only will the voltage output always be constant (as opposed to unregulated that can take advantage of the fact that a car battery is 14.4V not 12, but also will drop below 12V when the battery is discharged), the current supply ability will be affected.

Case in point: I have an older Alpine V12 4 channel amp. The V12 amps at that time either had a partially regulated or an unregulated power supply (higher power/cost ones were unregulated). The amp I have has a partially regulated power supply and at half impedance (say bridging two channels), the power output is about 2/3 of double. This is not a quality issue, rather a design choice - to keep the cost of the lower power amps (35W/channel is what I have), a regulated power supply with a finite current limit is used, and this limits the output power. The 50W/channel amps in the same line had an unregulated power supply, and at half impedance, power was doubled because current could double.

That all being said, an amp with an unregulated power supply is probably a higher end amplifier in general, so it is a feature to look at and ask about.

I hope I haven't mis-stated any info here.

Have fun with your install!

Dale.