Possible 4 Channel Amplifier and Front Speaker Upgrade

BMWAutos

Hello everyone,

I'm looking for a couple suggestions on my setup and what I'm thinking of doing.

My current setup is as follows:

Alpine CDE-9874 HU

Polk Audio db Series 5 1/4 Coaxial (Unfortunately I don't know the model number of the speakers.)

Stock BMW Tweeters

Polk Audio 6x9 db690

Alpine MRP-500 Amplifier

Alpine 12" Type R 4 Ohms

At first I wanted to upgrade all of my speakers to Alpine but after looking at specs of the 6x9 Type R's and the Polk 6x9's that I have I came to the conclusion that the Type R's are 2-way and 100W RMS. My Polk's are 100W RMS, 3-way, but go a little lower in the frequency range then the Type R's so why upgrade them?

My 5 1/4's which should be similar to the 5 1/4 Coaxial that Polk offers but perhaps an older model should be almost the same but are actually less powerful then the 5 1/4 Type R's which have 90W RMS.

Should I upgrade my Coaxial's to Type R's or keep them and just add a 4 channel amplifier? I was looking at the PDX-F4 and the PDX-F6 where the F4 gives out 100W RMS x4 and the F6 gives out 150W RMS x4 but the price difference is $300.00 according to Alpine's website.

Should I be looking at another brand amplifier?

Also, how does a 4 channel amplifier work? Do you take your HU RMS wattage and add that to the RMS wattage divided by 4 on the 4 channel amplifier to get what your total RMS wattage will be running on the speaker?

Thanks in advance.

BMWAutos

My concern with a component system is making sure the tweeters fit and if I can fit the crossover box somewhere for the component speakers.

KaosTsoc

BMWAutos wrote: »

My concern with a component system is making sure the tweeters fit and if I can fit the crossover box somewhere for the component speakers.

Thats the good thing about the SR's. They can be configured to be either comp, or coaxial. If you go active with the speakers then there is no need to fit the xover any where. However if you decide to keep the xover, then yes, the placement might be a problem. Another good option would be to go with MM series of polk. Granted they are not the SR's, but if you dont want to hassel with trying to place the xover somewhere then either stay with what you have, or go with the MM series.

If you are not going to use the HU to power your door's then the wattage of the HU does not matter, because if you just use the amp then you would run RCA's from the back of the HU to the amp. What is important if you plan on runing rca's if the volts per channel. You want to get a HU that is like 4 volt pre out or higher. If you plan on useing the HU to power the doors then an amp is not needed for the doors, but you would need an amp if you plan on running a sub, thus brings you back to the use of rca's. which is why alot of people will say to run rca's, plus the amp will give the speakers more life, and sound fuller. You will notice a difference.

A four channel amp is good to use if you plan on powering four speakres. Each channel gets is own power if you will.

So, if the speakers are 60 watts rms / 150 peak per speaker, then add all that up or 60 x 4= 240. Then you would want to get an amp that would put out at least 250 watts. However you do want to give your speaker a little more than the rms so, I would look for an amp that would be more like 300 watts rms, roughly 100 watts per channel. No more than that or risk over powering, and frying them. Hope this helps.


Thanks.

BMWAutos

Thank you for the replies.

I took some time to pull out my front 5 1/4 speakers today and here is the model number and specs:

http://www.crutchfield.com/p_107DB525/Polk-db525.html?tp=97&tab=features_and_specs

I'm thinking of upgrading to the db525i http://www.polkaudio.com/caraudio/db/specs.php

which will give me 100W RMS in the front and then I'll have my current 100W RMS 6x9's in the rear. Then I could power them with the PDX-F4 and have 100W going to all of my speakers which is what they are rated at.

The sr series components are a little too expensive for me atm so that's what I was thinking of getting the db components.

However, lets say the component setup does not fit in my car. Could I ditch the tweeter and crossover box and just put in the 5 1/4's and still have the speaker work the same with the 100W RMS output?

If that doesn't work I could always go with the mm521 speakers and still have 90W RMS.

KaosTsoc

As far as weather or not keep the rear speakers or not is well up to you. What skip is trying to get at is, if dont have people riding in the back seats that often, then you really dont need rear speakers. If you have people back there alot then sure go for it. As you read the posts on there, you will see that alot of people only run front speakers, and one or two subs. Really if you get a good pair of front comp's, and put the tweets in good placement, it will sound like you have all four speakers, when you only have two. However it is your car, and all we can do is help answer questions, and give ideas etc.

As for the PDX, yes you could use it to power all four speakers, if you plan on using the xover supplied by Polk.

As for fitting. If the DB do not fit, and you dont want to get the SR's, then the next best option is the MM line. They are super small, and dont take up alot of space. You dont want to ditch the tweeter that came with speakers. If anything ditch the stock tweeters. As for the xover box, that can go both ways. If you get rid of it, and keep the tweeters, the the PDX F4 will be good for the front only, they call it going active. Then if you plan on keeping the rears then you would need another amp to power those. However if you keep the xover box, then one PDX would be fine for all four speakers, they call this going passive if you keep the xover. There is a post on here that covers that as well.

But this brings me back to; it's your car, and your choice in the end.


Thanks.

BMWAutos

According to Polk's website the MM5251 fit my car. According to Crutchfield and Amazon the DB5251 and MM5251 fit my car.

They should both fit regardless, because its the same speaker size and the tweeter is probably 1" with the cover on. I'll have to figure out where to put the crossover box.

What's the difference between the MM5251 and the DB5251?

KaosTsoc

I would say that the biggest difference is the mounting depth for sure. The DB series use the traditional ferrite magnets, where the MM series uses neodymium magnets. There is also the impedance is different as well. The DB's are 4 ohm, and the MM's are 2.7 (2 ohm).

As for everything else they are pretty close. The other difference is price, and if I am not mistaken the sound is different as well. The MM's ofer a little more on the low end, where the DB's are kind of so so.

Thanks.

BMWAutos

Ok, that makes more sense now. I went by the KarTunes near my house to compare with what I'm looking at and I was told to look into some Focal speakers.

He gave me these:

130a1 5 1/4 component

690ca1 6x9 coaxial

He also said that the Focal speakers are actually underrated in terms of wattage so he said to put the Alpine F6 amp towards the speakers giving them 150W a channel. Which is 100W more on the components then what they are rated at. The rears would be 75W more then what they are rated at which is 75W.

BMWAutos

I wasn't even considering the Focal speakers until KarTunes threw me off. The SR series is expensive for my intentions right now and I should be content with MM considering I'm running a coaxial setup right now.

Do you think I would need to upgrade my rear speakers as well since they are the db series and may be lacking power that the MM series would have?

BMWAutos

I agree with the sound being pulled to the rear because all of the major bass and mids stay there because of my fronts and all of my treble is in the front because of my coaxial setup.

Putting SR's in the front and leaving the rears alone for the time being was an idea that I thougt of after I posted my previous reply. I could always get the SR's in the front and either the F4 or F6 for a 4 channel amp and hook all of my speakers up and I should be fine with that because there will be a difference considering the coaxial setup can't touch a component setup.

So SR's in the front, leave the rears, and get the F4 or F6 amp? I'm really not trying to go towards Focal speakers because I've never heard them and I have an idea what Polk products sound like because I have them in my car now.

I prefer having some bass in the front anyway because all of my low bass is in the back and right now I have hardly any mid bass. Its mostly treble in the front and if I turn up my HU there is bass in the rear and treble up front with a little bass.

BMWAutos

I tried out what you said about fading the sound to the front and rear and I preferred it to the front more then rear for sure. When I had it to the rear it felt like something was missing. When I put it back to the front I realized that the rear is lacking treble and it sounds muffled almost unlike the front because of the tweeters and coaxial in the front, but with a component setup it should sound perfect.

However, here is a question I asked KarTunes which I would like to clarify... I asked them what's the difference between ordering directly from the manufacturer website versus another online website such as Amazon. He said that some online retailers are not certified to sell those products so you don't get the manufacturer warranty. Is this true? But I think there are some certified sellers online such as Crutchfield and SonicElectronix? I forget how you spell the second one.

BMWAutos

Alright, thanks for the info. Why were they discontinued? Should I wait for the next model?

BMWAutos

Unfortunately my head unit does not support time alignment. I'm going to upgrade my head unit after I upgrade my speakers and add a four channel amplifier.

I looked at crutchfield's website and the SR5250's retail for 800 bucks. The one's on ebay are refurbished and I've always been skeptical on buying refurbished products.

But, if you say the SR series is being discontinued I can pick up the SR5250 off sonic electronix for 400 bucks. http://www.sonicelectronix.com/item_7107_Polk+Audio+SR5250.html

Do you think that would be smart?

There is also a 1 year sonic electronix warranty.

kawizx9r

BMWAutos, buy them through Fry's Electronics.

They're an authorized dealer (sonicelectronix is NOT). We just had a member purchase an SR sub recently from S.E. and it looked to have been refurbished. Same goes for the replacement sub he received after sending the first one back. Either that or keep an eye out on Polk's Ebay Store. That way, you are still covered by Polk...and well we all know their customer service is badass.

Just my .02

-Freddy

PS, I've seen the SR's on sale at Fry's for 329.99 a few times.

kawizx9r

DSkip wrote: »

The link I provided is their eBay store.

Gotcha!

When replying to certain threads, I tend to read the first post then the last 2-3 posts before posting anything.

BMWAutos

Have you ordered from Fry's before? I checked out the website and I can buy them for $356.72 plus shipping.

kawizx9r

BMWAutos wrote: »

Have you ordered from Fry's before? I checked out the website and I can buy them for $356.72 plus shipping.

Not ordered, I have one just 40 minutes away. In fact, I'm going there this Friday or Sunday cause the girlfriend is buying me a Polk MM12" Sub :biggrin:

Check their site out to see if there's one close to you.

BMWAutos

kawizx9r wrote: »

Not ordered, I have one just 40 minutes away. In fact, I'm going there this Friday or Sunday cause the girlfriend is buying me a Polk MM12" Sub :biggrin:

Check their site out to see if there's one close to you.

Yeah, I looked and no luck. I live in VA and all the goodies seem to be on the west coast of the USA. :frown:

However, $356.72 is a good price for what these speakers are. I think I might go ahead and purchase them.

Last question, PDX-F4 or F6? ... I can't decide.

BMWAutos

You mean, buy the PDX-F4 for 100Wx4 which will be enough and put that money towards something else?

BMWAutos

Well, I've had my Type R for almost a year now (I bought it last November) and my rears are fine for now. I've always wanted to upgrade to a component setup because the speakers I have now tend to be poppy at higher volumes because I don't have a four channel amplifier and lower end speakers.

Once I get these components and a four channel amplifier I'll probably look at upgrading the head unit next unless I'm content with what I'm hearing after the upgrade.

BMWAutos

I really appreciate the help that I've gotten here on these forums. Much better then the other forums I've gone to in the past which is a plus for me.

So I've come to the conclusion that I'll be buying the SR5250 off of Fry's for $356.72.

I've decided on the PDX-F4 considering that I don't think spending $300.00 retail for 50 more watts a channel is worth it, nor will I be able to tell the difference at this point.

I found the PDX-F4 for $288.99 with shipping on Amazon: http://www.amazon.com/Alpine-PDX-F4-Amplifier-4-channel/dp/B003GFZ6RI/ref=sr_1_1?ie=UTF8&qid=1288846539&sr=8-1

Any Pro's and Con's for choosing Amazon besides the 1 year warranty through Audiosource which is where the amp is coming from. I bought my sub enclosure through Amazon in the past.

arun1963

Look at the option of getting a hu that gives you more dsp. Time alignment, 5-7 band peq equalizer, ability to go active............This is the most imp part of your sound chain. I think Dskip mentioned this somewhere in this thread.

BMWAutos

arun1963 wrote: »

Look at the option of getting a hu that gives you more dsp. Time alignment, 5-7 band peq equalizer, ability to go active............This is the most imp part of your sound chain. I think Dskip mentioned this somewhere in this thread.

dsp?
How does the time alignment work?
Active meaning component?

Sorry, I'm new to components. :frown:

Would I need a new head unit right away or could I buy the speakers and amp first?

EndersShadow

BMWAutos wrote: »

dsp?
How does the time alignment work?
Active meaning component?

Sorry, I'm new to components. :frown:

Would I need a new head unit right away or could I buy the speakers and amp first?

Time alignment basically is the same in car audio as in home theater. It adds a lag to certain speakers to make sure the sound hits you at the same time from them all. For instance your ears hear the speakers closest to you first since they are closer. Time alignment adds a lag to the close speakers so the sound from them hits you at the same time as the speakers farther away.

Normally you set the timing for all speakers differently.

Going active means basically amping both the tweeters and mids with different channels of a amp. So instead of running one channel from your amp to your crossover and then splitting the connection (1 to tweets, 1 to mids) you send a signal to each (2 channels, one to tweets, one to mids).

DSP is something I am semi familiar with, but will let others that understand it better explain.

So here are your options as I kinda see them.

1. Go for volume/spl first (amp, speaker, etc) & then a new headunit
2. Go for quality first (good headunit, new good speakers) & then add an amp later

You can get the amp and speakers first and upgrade the HU later (this is what I am probably going to do). Conversly buying a new headunit is a much cheaper option to start with and you can always add an amp later on (since its normally the most expensive part). Its a tough call either way, but personally I recommend going loud first and then tweaking it with the DSP, Time Alignment, etc through a headunit later.

The only thing I will mention is if you are looking to potentially go "Active" you might need different speakers than what your considering since you need more channels to do "active". For instance my db6501's wont because I can only send 1 input to them, not 2.

BMWAutos

EndersShadow wrote: »

So here are your options as I kinda see them.

1. Go for volume/spl first (amp, speaker, etc) & then a new headunit
2. Go for quality first (good headunit, new good speakers) & then add an amp later

You can get the amp and speakers first and upgrade the HU later (this is what I am probably going to do). Conversly buying a new headunit is a much cheaper option to start with and you can always add an amp later on (since its normally the most expensive part). Its a tough call either way, but personally I recommend going loud first and then tweaking it with the DSP, Time Alignment, etc through a headunit later.

The only thing I will mention is if you are looking to potentially go "Active" you might need different speakers than what your considering since you need more channels to do "active". For instance my db6501's wont because I can only send 1 input to them, not 2.

When you say different speakers do you mean the rear speakers?

If I get components and then an amp I'll need to wire it towards all the speakers and when I get a newer head unit I'll need to rewire everything to go "active"?

BMWAutos

DSkip wrote: »

Get the amp and speakers. The head unit can come later. At this point, I don't think you'd understand what you would be looking for in a head unit and how it plays into your sound.

The speakers are a staple to your system no matter how you look at it. You don't need an amp to run them, but it is very highly recommended. Over time, you can research all the bells and whistles HU's offer. Its best to be educated when buying this since a nice HU can bring a system from decent sound to great sound.

I agree, I'm not familiar with these new features that newer head units offer. I still think getting the components and the pdx-f4 would be the best option for me and then in a month or two get a new head unit.

EndersShadow

BMWAutos wrote: »

When you say different speakers do you mean the rear speakers?

If I get components and then an amp I'll need to wire it towards all the speakers and when I get a newer head unit I'll need to rewire everything to go "active"?

Going active requires the ability on a set of components to have 2 inputs. IE you need 2 in's and 2 out's. The crossovers on my db6501's have 1 in and 2 outs (6 connections total). That was what I was refering to. So while I can still amp the tweeter and woofer, I cannot send them each their own specific channel from my amp. So if you compare the crossover pictures of the DB6501 to the MM6501, you will notice the DB6501 has 6 connections where the MM6501 has 8 (the extra 2 are for the second channel connection from your amp).

Going "active" would take a 4 channel amplifier and allow you to hook up 1 pair of components because you would go like this:

Channel 1: Driver Tweeter
Channel 2: Driver Woofer
Channel 3: Passenger Tweeter
Channel 4: Passenger Woofer

as DSKIP said, go with the amp and speakers. No matter what changing out speakers is going to make a very big difference. I hope I clarified things a bit.

EndersShadow

DSkip wrote: »

This isn't going active. What you described was biamping your fronts. Going active means bypassing the passive crossovers supplied with your components and having an active crossover instead. The benefit to this is you get to change the crossover points on each speaker so that it sounds best in your car. Having control over the crossover points can greatly change the overall sound you get out of the speakers. You do this through processing that is available in separate processors and even some head units. My HU, the Pioneer 860, has this capability and it is another great function I couldn't live without.

A crossover point is the point in the frequency range where a speaker will be cut off. For instance, for tweeters, they are usually cut somewhere in the 3k-5k range You don't want them playing much below that because they have the potential to be destroyed (as well as kill your ears). The lower the frequency, the more excursion it takes to create that note. Tweeters aren't meant to have great excursion since their sole purpose is the high end of the spectrum.

My apologies on the mistake on my end. So that I understand you fully, basically you cut out the physical crossover entirely and wire straight from the amp to the tweeter or woofer (instead of amp to crossover to tweeter) or am I mis-understanding you? Then you set the crossover in the headunit for the first set of RCA's to lets say in the 3k-5k range. You would then wire the tweeters etc to the RCA's on the amp that are getting that signal. Then repeat this process for the woofers (modifying the crossover points) correct?

KaosTsoc

BMWAutos wrote: »

Any Pro's and Con's for choosing Amazon besides the 1 year warranty through Audiosource which is where the amp is coming from. I bought my sub enclosure through Amazon in the past.

Well I hate to say, but amazon is not an authorized seller for Alpine. Here if you go to this link it will show you at the bottom who is an authorized internet seller for them.

http://www.alpine-usa.com/stores

So, alpine might not honor their factory warrenty if is was not bought by an authorized seller.


Thanks.

BMWAutos

DSkip wrote: »

What is your current HU?

Alpine CDE-9874

http://www.crutchfield.com/p_500CDE9874/Alpine-CDE-9874.html?search=cde9874&tp=5684&tab=features_and_specs

As far as wiring goes, what are my options since I won't be getting a new head unit until after I have my amplifier and component speakers?

BMWAutos

So I went ahead and ordered the SR5250 speakers off of Fry's and the PDX-F4 off of cartoys.

cartoys had the lowest price for the amplifier and it is authorized by alpine according to their website and someone said that fry's is authorized by polk as well.

I'm looking forward to these speakers and powering my car with 100W a channel. :biggrin:

I'll let you know what happens and how they are.

Thanks again for everyone's help.