? regarding db650

mach189

I apologize if this question has been asked before but I couldn't find the answer through a search. I have a '02 Maxima and I've replaced the factory components in front and I just bought the db650 for the rear. I'm currently running the components off of my factory headunit and will be installing the db650's soon along with an 4-ch amp. Here's my problem...not that I expected the aftermarket components to sound like a sub but there is even less bass than with the factory speakers. I'm curious if adding the polks's to the rear will compound this problem or will they provide at least the same amount of bass as before.

Also, I've heard numerous people on various sites write that the db650's were great speakers but didn't produce much bass. I'm not looking for sub-type bass, just something to sound decent. Do they mean that compared to subs they don't produce much bass or compared to stock speakers? I'm not sure what they mean by "not much bass".

Lastly, will the addition of an amp make a noticable difference in the sound of aftermarket speakers despite still using a stock headunit?

I know this is sort of jumbled and confusing but my problem is just that.

1996blackmax

Since you own a Maxima, I have a nice website for you (maxima.org). The link below is directly to the audio forum there. There are quite a few forums there. Read the audio stickies as there is good information there regarding our cars. As far as the addition of an amp, it will help the overall sound of your speakers. You will have louder, cleaner power available. What components do you have up front?

http://forums.maxima.org/forumdisplay.php?f=25

Greg Peters

How long have you been running the db650s? They do take a bit to break in/loosen up, and will play lower after a few weeks of usage. They do produce more lower mid-bass frequencies when amplified as well.

Generally speaking, factory (paper cone type) speakers are a trade-off, in that they are designed to make mediocre bass/mids/highs, good enough for the non-audiophile, but still not great. You will probably find that the cones in your db650s are somewhat stiffer than the factory speakers you replaced (and should get more power for best results).

Many factory head units have an automatic but non-adjustable EQ feature built in that cuts bass as the volume increases (to avoid blowing the factory paper cone speakers) for reasons mostly concerning warranty. Amplifying the signal from the factory head unit for your db650s will not change the equalization of the signal, and the result will still be reduced bass frequencies as volume increases.

Something like the JL Audio Cleen Sweep, or the RF 360.1 / 360.2 can remove equalization from the factory head unit's signal (if you insist on retaining it rather than going aftermarket) but will add several hundred dollars to the equation as well.

For best results, use the db650s with a quality aftermarket head unit, an external amplifier, and even better- with a subwoofer dedicated to reproducing frequencies below 80hz. They don't sound too bad powered off an aftermarket head unit alone (if you want to upgrade in stages), which would be a better alternative than the factory CD player for sound quality purposes.

mach189

Thanks guys, I appreciate the response.

I have Infinity Reference 6010cs components and I'm not real impressed with the highs, they are almost unbearable sometimes. I haven't installed the Polks yet but will in the coming weeks.

Do you guys have any suggestions on an amp? I'm looking at the Power Acoustik LT/720-4. I used Polk's wattage guide (.75 x rms) and figured 85rms would suffice. The components are 90rms and the polks are 60 rms.

MacLeod

Yeah, Infinity kinda sucks. Ive owned their speakers before and they are so bright it hurts your ears. On some jazz and stuff they were ok but anything with solid guitar work was just painful.

As for making bass, OEM speakers do make more bass than a typical aftermarket speaker. However, more bass doesnt mean better bass. Because there is usually no sub OEM speakers are designed to make more bass to please their customers and they do but its not very tight or musical nor does it reach very low. Also, it makes this extra bass at the expense of the midrange and definitely the high range frequencies. Compare the mids/highs of your factory speakers to your current ones (even tho theyre Infinitys theyll still far outperform those crappy stock speakers).

Aftermarket speakers are designed to reproduce their natural frequencies well, i.e. midrange speakers that produce 80-3000 Hz and tweeters that take care of 3000 and up. And since a speaker that plays midrange frequencies well cant play sub bass well, they dont design them too. For good sub bass you have to have a sub, there is just no way around it. Think of it like engines. Yeah, they make the 4 bangers as powerful as they can but if you want to tow a big boat and trailer, youre going to have to step up to a V8. Same principle here.

By adding an amp, however, you will notice quite a bit better bass response out of your speakers for because of the extra power. It takes a lot more power to reproduce low end frequencies well and an amp has that extra power. Your stock head unit is a pitiful power source and so that reduces your speakers bass response even further.

Greg Peters

The Infinity tweeters can be too bright- almost screechy- and the mids break up really easily if you try to push much bass out of them (been there, tried that).

The polk db's are good in the mid-bass department, have smoother but less pronounced highs. I find I have to boost high frequencies with these speakers for optimum sound (to my taste), and even then would prefer somewhat brighter tweeters than the dbs offer.

I wouldn't think that these two manufacturer's speakers could learn to play nice with each other in the same car, UNLESS you were to buy something capable of applying different EQ curves to front and rear channels independantly (like an AudioControl EQS). Factory bass and treble controls couldn't tame the differences between the two sets of speakers and still give acceptable SQ overall. A cut in the high frequencies in attempts to tame the Infinitys would likely make the dbs sound downright flat, muted, unnatural.

Almost any entry-level amplifier from a reputable brand in the 50-75 watt RMS range would do nicely for the db650s. Check some other threads, as there are a lot of very nice amps recommended for reasonable prices. The Power Acoustik may be OK, but also consider ARC, MTX, Crossfire, Alpine, JBL, RF, etc... just make sure the one you choose is compatible with line-level inputs if you still plan to amplify the signal from the factory h/u.

mach189

I have one last question. I know Polk says to use the 3/4 rule to choose an amp based on te speaker's rms, but on this site it also says that it's better to buy a more expensive amp even if the rms is lower than one that is cheaper but states more rms. For my situation just powering components and coaxials, no sub, would I need to have an rms near the what the speakers are rated or would something with about 50rms suffice? I can't seem to figure this out.


Again, I appreciate the help guys.

98thumpin

ok first of all, you have db650 speakers and they are rated at, Nominal Impedance 4 ohms
Power Handling (continuous) 100 w
Power Handling (peak) 300 w
Efficiency 92 dB
id say go with the polk audio C400.4 (4/3/2 Channels)
4/3/2 Channel Power Amplifier
Championship Performance

100 watts x 4

mach189

98thumpin wrote:

ok first of all, you have db650 speakers and they are rated at, Nominal Impedance 4 ohms
Power Handling (continuous) 100 w
Power Handling (peak) 300 w
Efficiency 92 dB
id say go with the polk audio C400.4 (4/3/2 Channels)
4/3/2 Channel Power Amplifier
Championship Performance

100 watts x 4

The db650's are 60w continuous and 180w peak. I would love to have the Polk C400.4 but it is a little out of my price range.

98thumpin

heres a link for a good nakamichi 4 channel amp should fit the bill at a nice price too
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=11694

* 4X50 WATTS @ 4 OHM
* 4X100 WATTS @ 2 OHM
* 1X400 WATTS @ 4 OHM BRIDGED
* SENSITIVITY: 98dB
* ACTIVE 12dB LOW AND HIGH PASS FILTERS
* SUBSONIC FILTER
* REMOTE BASS LEVEL CONTROL PORT
* OPTIONAL RBC1
* DIMENSIONS: 11-1/2" X 2-1/8" X 14-7/8"

98thumpin

do you have the components or coaxs, cause i got the info for the components. sorry but i didnt know, check on phoenix gold the, or nakamichi heres a link.
* 4X50 WATTS @ 4 OHM
* 4X100 WATTS @ 2 OHM
* 1X400 WATTS @ 4 OHM BRIDGED
* SENSITIVITY: 98dB
* ACTIVE 12dB LOW AND HIGH PASS FILTERS
* SUBSONIC FILTER
* REMOTE BASS LEVEL CONTROL PORT
* OPTIONAL RBC1
* DIMENSIONS: 11-1/2" X 2-1/8" X 14-7/8"

mach189

I have the coaxils but I think the components are db6500 if I'm not mistaken. The Nakamichi looks nice but it's still a little out of my price range. I'm not looking to spend too much money on an amp, just enough to get my speakers to sound better. Basically something that will provide more power than my factory headunit.

audiobliss

Yeah, the components are the db6500. The db650 is a coaxial.

neomagus00

this kicker amp is a hot buy right now, and fits the bill well

mach189

neomagus00 wrote:

this kicker amp is a hot buy right now, and fits the bill well

I've got components in front and I'm adding the 650's in the rear. Wouldn't I need a 4-ch instead?

98thumpin

well the 4 ch will run a little higher than a 2 channel, but i wish you luck with an amp that price i gave you was the best i could finw without getting into walmart crap.

neomagus00

mach189 wrote:

I've got components in front and I'm adding the 650's in the rear. Wouldn't I need a 4-ch instead?

yes you would, my bad, i forgot the rears .

this eclipse is 75 x 4, this jbl has a little more juice, 100x4, for a little more money

98thumpin

love that eclipse amp i like the clipping light feature to make setting gain easier no guesswork. thats real nice. not to mention its an eclipse. the jbl looks cool to with the clear top and jbl from what i know makes a good amp.

mach189

Would it be better to match the speaker's rms more closely with a lesser quailty amp or buy and amp that's better quality but puts out only 50rms?

Would I, or my speakers, really notice a difference in 50w per speaker or 75w?

MacLeod

Depends on how much lesser quality. You dont want to be running a Pyramid or some other flea market crap no matter what. But say youve got 100 watt speakers, youd be better off getting a 100 watt Rockford Fosgate Punch amp as opposed to a 50 watt Xtant.