Polk db6500 in front and Polk ex357 in rear

sidespin · February 2005

This will be my setup as I purchased the db6500 components for the front. I originally purchased the Polk ex357 for all my speakers, but decided I wanted to go for a full-out component set for the front.

My stock HU is still powering them, and I plan on amping them, but not sure what kind of power will be sufficient.

There's an Infinity amp on Crutchfield that delivers about 111Wrms X 4 @ 4ohms. I'm thinking this may cause clipping, as the db6500 are rated at 100Wrms and my ex357 are rated at 60Wrms.

Would a 4-channel amp that produces 50Wrms X 4 @ 4ohms be sufficient enough?

Or an amp that produces 75Wrms X 4, would that be alright as well? I don't know too much about amps and what will cause clipping, so I want to make sure I buy the right amp to power these speakers.

Fronts: Polk db6500 components
Rear : Polk ex357

Any input would be much appreciated. Any suggestions for amps would also be appreciated. I've read Macleod's amp suggestions, so I think you would recommend MTX amps or the Crossfire amps.

I'm looking to spend around $200 for the amp, so any suggestions would be really helpful.

I've been browsing a lot of late, but I notice there's not too much activity on these forums. Probably cause it's Polk-specific. Anyways, thanks!!!

exalted512 · February 2005

if you want sound quality, youre better off not running any rear speakers, but some people like em, so if youre one of those people, then id look for an amp that did about 100x4. that infinity wont cause clipping, the db components will be perfectly fine, youll just have to turn down the gain a little. check sounddomain for better prices though. also might want to check onlinecarstereo.com for HiFonics, ive always been a fan of their equipment.
-Cody

sidespin · February 2005

Thanks Exalted. I'll look into the Hifonics amps.

I am one of those people that would like to have rear speakers. I have read about soundstage, but I have back seat passengers sometimes, and I just think it would be nice if I had speakers in the back too. They are Polk speakers, but the power handling is lower.

The Polk ex357 in my rear handle 60Wrms, so would a 100Wrms X 4 amp be too much power going into them? This could cause clipping if I understand correctly. I'm not sure though.

exalted512 · February 2005

clipping is more due to trying to get more power of the amp. like if you have 100 watt speakers and a 50 watt amp, a lot of people tend to turn the amps gain up to where the amp is pushing itself too hard and will clip thus sending the signal to the speakers potentially blowing them. The gain is a knob on your amp that is meant to be set according to the voltage on your preouts. But you can turn this down for your rear speakers so it wont send as much power to them. i think 100x4 would be perfect for your application. Its always better to have a little more power than too little. This way you can turn the gain down a little and your amp wont be working so hard. Honestly, those EXs could probably handle a lot of clean power, but to be on the safe side, turn the gain down.
-Cody

sidespin · February 2005

awesome response exalted. much appreciated. i didn't know what clipping was actually referring to, and that cleared it up.

can i turn the gains down just for the rear speakers, and leave it at normal setting for the fronts? or if i turn the gain down, does it decrease the power for all the speakers then? there's probably no "normal" setting, but maybe just in the middle setting of the dial.

I have yet to see an amp, so not exactly talking out of knowledge here, but trying to get an idea of what i will need to do. also, of what kind of amp i should be looking into. Also, when people say clean power, do some amps output, "bad power". if you played an amp at its recommended level, wouldn't this always be a clean signal or not? Because I see the Profile amps on Crutchfield for like $89 or $139, and they are rated at 100Wrms, while another amp in the same price range, is outputting 50Wrms.

sidespin · February 2005

Specifications for Polk ex357

Sensitivity 91 dB
Frequency Response 55 - 22k Hz
RMS Power Range (Watts) 2-60
Peak Power Handling (Watts) 180
Impedance (Ohms) 4

My Polk ex357 are already in all 4 door speakers of my car (Mazda3

). I'm going to switch out the fronts for the components and then amp them.

Exalted you think a 75wrms or 100wrms x 4 will be better?

From your last response, I'm guessing 100Wrms x 4, as I can always turn down the gain, right?

Thanks

MacLeod · February 2005

The thing to remember about matching power to speakers is this. There are only 2 things that kill speakers. 1- over extension of the cone beyond the limits of the suspension (too much power). 2- Heat being built up in the voice coil faster than it can dissipate (too much power). If you have a speaker that dies at 100 watts, then 101 watts will kill it regardless if its a clean or distorted signal. A speaker can play a signal distorted all to hell if its below its power handling limits.

When an amp clips, the signal it sends out is at as much power as the amp can put out and limited only by the input voltage. In other words, if a 100 watt amp clipped, the signal it sent out would be in the neighborhood of around 200+ watts.

So if you have a 50 watt amp on a 75 watt speaker and push the amp too hard, itll clip, send out around 100 watts and bamo! Dead speaker.

Now when you take a 100 watt amp and push a 75 watt speaker, youre less likely to push the amp as hard so youre less likely to clip the amp. However, you push the amp enough so that it puts out its 100 watts to the 75 watt speaker and itll kill it just as quickly as the 50 watt amp did.

So what does all this mean? Power your speakers properly. Make sure your amp has enough grunt so that you dont have to push it very hard and thus youll likely never exceed the speakers limits. But that doesnt mean get a 200x2 amp for a pair of 50 watt speakers. This would have as much chance to damage them as anything else.

So I gues the point to all this rambling is that for those 60 watt speakers I would look for something in the 75 watt neighborhood.

As for gains, think of it like this. Say your head unit is at 100% power with the volume at 20. Now if you turn the gain on the amp all the way up then your amp will be at 100% when the head unit is at about 8-10 so if you go beyond 8-10 your amp is running balls to the walls and clipping like hell sending out a distorted, crappy signal.

You match the gain up properly and when the head unit is at 50%, the amp is at 50% and everybody lives in harmony.

exalted512 · February 2005

yes, you can turn down the back seperate from the front.
profile amps are pretty damn good for what you pay for. theyre not the best, but are great in their price range.
i suggest HiFonics because they are a great company and onlinecarstereo.com has them for insanely cheap. if i wouldve found that site when i first got my amps i wouldve gotten HiFonics over my currert rockford fosgates. theyre very good amps
-Cody

sidespin · February 2005

Hifonics NX880
Nemesis 400W 4-Channel Power Amplifier
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=13125

Kicker KX300.4
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=11943

Phoenix Gold R8.0:4
Octane R Series 4 Channel Power Amplifier
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=12979

Hifonics TX8805
4 x 220-Watts Amplifier
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=14797

I want to stay around the $200 price range, as these seem to be a little over that price, but out of these which would you recommend for my system?

Fronts: Polk db6500 components

» recommended power range 10-100 watts RMS
» peak power handling 300 watts
» sensitivity 92 dB
» frequency response 40-23,000 Hz

Rear: Polk ex357
» recommended power range 2-60 watts RMS
» peak power handling 180 watts
» sensitivity 91 dB
» frequency response 55-22,000 Hz

No sub at the moment. I want to amp the speakers first, then if I need more bass, I can add a sub later, but I don't want to splurge all at once.

MacLeod · February 2005

Its gonna be hard to get a good 4 channel for under $200 unless you buy from an unauthorized retailer and I never recommend that. Not only do you get no warranty but youre taking pot luck. You may get brand new equipment. Then again you may get remanufactured junk, open box stuff, not telling what.

Also, all of those you listed except the PG are discontinued so theres no telling what youll be getting.

But out of the ones you listed, I would take the Phoenix Gold first, Kicker second.

exalted512 · February 2005

i disagree. id do business with onlinecarstereo any day of the week. theyre not authorized, but they do carry a 1 year warranty. thezeb.com on the other hand is authorized and i will never order from those asswipes again
-Cody

sidespin · February 2005

ahhh, such contrasting opinions on various issues. i guess this is where my gut instinct kicks in.

i actually bought my Polk PSW 303 Home Theater sub off of Ebay, and it is still marvelous. Brand new of course, and have had no problems whatsoever with my equipment. Unauthorized retailer, but still trustworthy after reading feedback.

Onlinecarstereo seems like a very legitimate site, and i think i will order from there. still not sure which amp yet, but at least the prices are very encouraging.

thx for the good advice Macleod and exalted. Anyone else want to chime in with their thoughts or experiences, I welcome you to add your comments.

Thanks again.

MacLeod · February 2005

Thats about it. Cody and I are about the only guys left around here it seems.

Cody wont steer ya wrong and he has had great success with OCS and Ive never ordered anything from there. Just that me personally I am skeered to death of ordering stuff online anyway so I never do it unless its with an authorized dealer.

Just for the hell of it tho you can go here and read consumer reviews on OCS. You can also look up SoundDomain and Crutchfield. Crutchfield doesnt have hardly ANY negative reviews but their prices are as high as a retail store.

sidespin · February 2005

Thanks Macleod. Much appreciated. Yeah, Crutchfield tends to be pretty pricey, except when they have an item on sale it appears.

I finally installed my components today, and definitely awesome. I can't wait to amp them and truly get the full sound and clarity. I can hear that they aren't being powered enough by the stock HU, which outputs probably around 10-15W. So, once I get a good power source for these babies, I'll be bumpin.

Thanks both of you guys, Macleod and exalted for chiming in.

spwuinmk67 · February 2005

Originally posted by MacLeod
Thats about it. Cody and I are about the only guys left around here it seems.

Naa...theres adam with his...comments. And I give...well little to no advice but I am here. I usually only have time to read what goes on...work sucks. But the money is nice, especially the $3000-4000 I made during the month and a half of chritsmas time I worked at RS. So now that it's slow, I need a second job, which I have, but leaves me no time to post. I'm trying to post more though...maybe gain some knowledge.

MacLeod · February 2005

Dude, you work at Radio Shack?

Ive been thinking about applying there. Is it a pretty decent place to work?

spwuinmk67 · February 2005

If you get into a high volume store, yeah it's great. I started just before black friday, with no sales experience. My 2nd or 2rd paycheck, was $1800 after taxes. Awesome. It's nice cause you can learn how to sell, they'll take the time with you. You can learn a lot about a lot of different stuff, plus you get discounts. 30% on all RS products, 10% on all other stuff. Monster products...if we carry it in the store, and you buy it right then and there, 30% off, if you get monster certified, and fill out a form, and wait a month, 60% off. While some of you are on the monster boycott....60% off some RCA's and 1/0 guage power wire, I'll be happy with. Cell phones are a great thing to sell. You can make mad money off of those. All the little add ons add to your pocket too. Besides that stuff, you also get discounts on other things, travel packages, houses/apartments, cars, getting your taxes done, etc. Good place to work.

MacLeod · February 2005

That sounds cool. Ive got no retail sales experience so I wasnt sure if they would hire me or not.

I assume they pay on commission. That kinda sucks. Im on commission now and its pretty slow this time of year.

We've got like 1200 Radio Shacks in this town so surely I can find one that is hiring!

spwuinmk67 · February 2005

They should hire you...as far as pay goes, you get whichever is more, your comission or your hourly. It's minimum wage for the hourly, but if you sell enough, you get the comission. Very rarely do i get the hourly. As i said, cell phones are your friend. Plus employee plans are nice for them too.

MacLeod · February 2005

Hmm..so would bringing home $350-400 a week be outrageous?

spwuinmk67 · February 2005

See in my store, I've been stuck on mornings for the past 4 weeks, due to other peoples schedules. And morning in this store suck, its old people. Hi, you have hearing aid batteries? or its phone batteries, or can you explain this or that, its all little ****. Even with that though, my paycheck is like $550 or so, for two weeks. But if i had nights, id be makin a lot more. We have one guy who brings in around $1000-$1500 every two weeks, granted hes probably one of the 2 top salesmen in the district, but still, it is possible. Before you start, I'll tell you something, people are stupid. Sound like you know what your talking about, and they'll believe it. you'll learn little trick here and there on how to get a little more out of people.

Polk db6500 in front and Polk ex357 in rear

Comments