New system...thoughts?

SportsFan

Hey guys,

I just added an Alpine CDA-9847 head unit along with some Polk Audio db650s for the front, and Polk Audio db690s for the rear of my '98 Accord sedan.

Now, my days of "cranking" the stereo to near deafening levels are over with, since I'm closer to 40 than I am to 30. But I still like music, mainly all forms of rock....and wanted something other than the factory AM/FM cassette (which was in the used Accord that I just purchased).

I've been reading various threads, and it seems that everyone is recommending an amp for practically every situation.....but I've gotta be honest, it's been a while since I've had a really good car stereo (after my last one was stolen about 7 years ago, I've simply made do with factory CD players in my last couple of vehicles) But I won't be adding a sub, and I simply just don't crank it up like I used to when I was younger and wanted the neighbors to hear me coming down the street...or like when I was trying to impress people while going deaf in the process.

But still, even though it sounds fine now....I'm brand new to both Alpine AND Polk Audio. I've had Pioneer, JVC, Sony, etc., products in the past....so I'm not sure exactly what to expect. The Alpine is rated as a "50W x 4 High Power Amplifier" (18 watts RMS x 4), while the 650s have a "recommended power range of 6-60 watts RMS, with a peak power handling of 180 watts".......and the 690s have a "recommended power range of 10-100 watts RMS, and a peak power handling of 300 watts". So does this mean that I should be OK listening at "lower to moderate", or even to semi-loud (for the head unit) volume levels, or that I am actually potentially harming the speakers by not pushing the "proper" power through them on a consistent basis? I liked the sound of these speakers and head unit when shopping around, and had even planned to add an amp...but after listening to them once the Alpine was installed in the vehicle, I wasn't sure that I actually needed an amp (to make the system any LOUDER for my tastes). But I certainly don't want to "damage" the speakers either by not pushing them properly.

I'm sure that I sound like an idiot to many of you audiophiles and electronics pros out there, but I simply haven't paid that much attention to aftermarket stuff the past several years and am just getting back in the game after a layoff. So any help in this would be very much appreciated......

cam5860

It won't hurt anything to run them off that deck, but they need to be amped. I would buy the 4 channel alpine v-power amp to run them. You can pick one up at bestbuy right now for 175.00 bucks. You won't realize what your missing out on until you amp those db's. I used to have a set. I started out running them off my deck, but when i amped them man it was like night and day.

brettw22

I'm in the same boat in that I haven't ever had an amp when I've installed speakers in the past. I think it has a lot to do with the speakers that you buy whether or not you'll still have good sound and not necessarily require an external amp. I think I put Infinity speakers in my Maxima years ago and I didn't really have a problem with the new Pioneer deck that I was running them off of. With the system I'm going to be having installed in the next week or so, I'll be able to give you a better answer....

Think of it this way though (addage compliments of the Home Audio group)......equate having an amp vs. not to having a v8 vs a 4cyl. They'll both go the same speeds, but the 8 will be more effortless doing it.

MacLeod

Brett's right. You dont have to have an amp and running those speakers off the head unit will give you good sound and be much better than the factory crap you had before.

The problem with head units is that they are so small they cant make much power. An inexpensive 4 channel amp will make 50 watts per channel where a head unit, regardless of its claims, will only make about 10. More power will sound better than less power, to a point anyways.

Having an amp isnt necessarily about being louder. It means having more power to make better sound. Like Brett said, a 4 banger will haul you down the road at 65 mph just fine but when you want to pass, pull a hill or haul a heavy load youll wish you had a V8.

Bottom line is if youre just wanting some tunes to listen to for the daily commute but want better than the factory offereing then head unit power will be fine. But if youre wanting to listen to and enjoy every nuance of the song and to really get into the music itself and want the best sound quality you can get an amp is practically a necessity.

SportsFan

Thanks for the input and feedback, guys.

I guess I'm leaning a little towards eventually adding an amp now....and one that I'm looking at is the Alpine MRP-F240. Here's the link to it through Crutchfield:

Alpine MRP-F240 through Crutchfield

Looks like a decent amp, that would definitely add some power.....although it still wouldn't be anywhere near the 100W RMS that the Polk db690 offers. Small sized amp....could possibly install under a car seat (?).....I dunno, but that would be really nice (like to avoid a trunk install, if at all possible).

Anyway, does anyone have any experience with this particular amp? Would this be a decent amp for the rest of this system and for this car, or should I look for something a little more powerful?

MacLeod

That is a great little amp. I used it for a couple years. Itll easily make its rated power cleanly but dont expect any more than that. Its not a powerhouse but it will deliver good, clean power all day. Add to that, its pretty small and inexpensive. That would be a great choice for your particular application.

SportsFan

MacLeod wrote:

That is a great little amp. I used it for a couple years. Itll easily make its rated power cleanly but dont expect any more than that. Its not a powerhouse but it will deliver good, clean power all day. Add to that, its pretty small and inexpensive. That would be a great choice for your particular application.

Thanks for that info, Mac.

Since you have used this amp.....hopefully you can tell me something. I'm curious if adding an amp will truly "boost" the bass responsiveness, from an increased depth and range standpoint....or if it mainly just amplifies the sound, making what is already present louder.

The system I have now has really good mids and highs, and what I would consider to be "decent" bass response. Because I've never "amped" a system before (have used a combination "booster/equalizer" previously), I don't know if the amp will increase frequency range and tonal depth, or if it is primarily to increase the volume. I'd like a little richer and deeper bass response, without increasing distortion.....and I noticed that this amp has a "tuned Bass EQ (0-12 dB bass boost at 50 Hz) for channels 3 & 4" feature. So in your honest, expert opinion.....will this amp do what I'm looking for? Or would an MTX Thunder 564 amp be a little better fit, or are they both fairly comparable?

MacLeod

The lower in frequency you go, the more power required to make it sound right so yes an amp will increase the bass output of your current system.

Still, having the power is only half the battle, you have to have the speaker that is capable of producing the bass. You hit sub 80 Hz frequencies with authority you need to move a lot of air and a typical 6.5 or 5.25 or even 6x9 speaker doesnt have the cone area or the Xmax available to move enough air.

So while adding an amp will improve the bass response from your DB's youll never get good solid bass without a sub.

SportsFan

Hey Mac....thanks again. I hear what you are saying, and understand what you mean - that does make a lot of sense. But when you used this particular Alpine amp (Alpine MRP-F240) that I asked about, what kind of a system were you running it through? One WITH a sub, or without? And if without (hopefully being the case), did you notice much of an improvement in bass response? And what exactly does the "bass boost" (0-12 bd at 50 Hz for channels 3 & 4, etc.) feature do for sound quality? If you don't mind, please share with me what you discovered when you used this particular amp (since I'm seriously thinking of adding it).

MacLeod

I originally started running it thru some Infinty 6x9's and then upgraded to the PolkMomo 6x9. It did increase the bass response quite a bit and overall SQ improved. I ran a MTX 8" sub off the 2 channel version of that amp.

As for bass boost, all that really is, is a bandaid. While it does add db's at the specified frequency it creates a big response hump at that frequency as well. You never need to use the bass boost on speakers other than subs because they wont be able to reproduce the 50 Hz very well anyway and adding 12 db of boost to that frequency will not only cause them to distory pretty bad but could also kill the speaker. Save the bass boost for the subs, but the best way is to get the proper amp and not use bass boost at all.

So bottom line, you will notice an increase in overall SQ and a decent increase in bass response with this amp but youll never get "proper" bass without a dedicated sub and amp.

SportsFan

brettw22 wrote:

I'm in the same boat in that I haven't ever had an amp when I've installed speakers in the past. I think it has a lot to do with the speakers that you buy whether or not you'll still have good sound and not necessarily require an external amp. I think I put Infinity speakers in my Maxima years ago and I didn't really have a problem with the new Pioneer deck that I was running them off of. With the system I'm going to be having installed in the next week or so, I'll be able to give you a better answer....

Think of it this way though (addage compliments of the Home Audio group)......equate having an amp vs. not to having a v8 vs a 4cyl. They'll both go the same speeds, but the 8 will be more effortless doing it.

Hey Brett....glad to know I'm not alone in trying to decide what to do here

I'm leaning towards getting some sort of an amp....probably the Alpine I asked about. I would like to add a little "boost" to the overall sound quality and volume level....but honestly, what I have now sounds pretty good and has decent volume. Therefore, I'm not looking to "win any contests"...just add a little volume and SQ to the equation.

But be sure to let us know what you get, and how it sounds once you've got it installed.......

MacLeod wrote:

I originally started running it thru some Infinty 6x9's and then upgraded to the PolkMomo 6x9. It did increase the bass response quite a bit and overall SQ improved. I ran a MTX 8" sub off the 2 channel version of that amp.

As for bass boost, all that really is, is a bandaid. While it does add db's at the specified frequency it creates a big response hump at that frequency as well. You never need to use the bass boost on speakers other than subs because they wont be able to reproduce the 50 Hz very well anyway and adding 12 db of boost to that frequency will not only cause them to distory pretty bad but could also kill the speaker. Save the bass boost for the subs, but the best way is to get the proper amp and not use bass boost at all.

So bottom line, you will notice an increase in overall SQ and a decent increase in bass response with this amp but youll never get "proper" bass without a dedicated sub and amp.

Since I'm not going to add a sub (I'll just be sticking with the db650s and db690s), I'm glad to know that the bass response and sound quality was improved when you ran both your Infinity and Polk Momo 6X9s through this particular Alpine model. I'm not looking for a huge upgrade, but I'm sure this little amp will provide me with all that I need (provided that it can be mounted under the front car seat. I want to avoid using the trunk if at all possible, because I use it to carry luggage and haul other things from time to time....)

MacLeod

That it will. It wont be up to par with some of the bigger amps out there but it will be head and shoulders above the head unit as a power source. And it is quite small and especially thin for a 4 channel so you shouldnt have too much trouble fitting it.