Why is the bass not as good as factory speakers?

ngv1515

Hi guys I'm new here.

I am a Auto Technician so I am very good at understanding some stuff BUT sound is not my specialty.

I just got a 1998 Civic as a project car for my kid and I. We are starting with the sound system. We are not going for crazy loud but we are going for quality and clear sound. First we got a Alpine head unit UTE-62BT this unit has 18 RMS x4 and it works great with the factory speakers but the highs were terrible. The next step were the speakers.

I got;

Polk DB+ DB6502 6-1/2" Component System for the front
Polk DB+ DB692 6" x 9" 3-way Speakers for the rear

I also got Speaker Baffles for the front and rear. I didn't make holes on them only for the wires.

I left the driver's speaker factory to compare (the only one not blown) and I noticed that the bass is WEAK on the Polk woofer on the right side compared to the factory left. I also noticed that the Polk woofer barely moves at max volume (before speaker distortion) while the factory speaker is going crazy. My guess is that the Polk woofer needs more power to be able to produce bass. I am not expecting to sound like a sub-woofer but at the very least BETTER that factory.

Don't get me wrong here I love how the highs sounds, its super clear!!

I'm sure I would need a Amplifier but I am not sure what amp rating I sound get. the description for the front says that it handles up to 100 watts RMS for the front and 150 watts RMS for the rear. Is that per speaker? or combine?

What amp do I need?
100 RMS x4 4 channel amp?
150 RMS x4 4 channel amp?
50 RMS x4 4 channel amp?
75 RMS x4 4 channel amp?



Thank you

I have some pics of the front install.

stangman67

My response from the other thread for reference.

Nice looking install. This post may serve you better in the car audio sub forum. Even then most guys on here are Home audio gurus.

I have background in car audio, the reason that the bass performance is not as good is

a) HU power will never serve a good set of aftermarket speaker well.

Factory speakers are designed to boost bass frequencies as there is no reasonable expectation that a subwoofer will ever be used, so the factory speakers have to "do it all". Aftermarket companies are focused on generally creating a more accurate speaker, IE one with a flat frequency curve. 6.5 inch drivers are not adept at creating bass frequencies and cannot dig down into the lower frequencies, so they are designed to create flat frequency response in the frequencies they can accurately reproduce. Aftermarket companies are expecting people that want loud bass will install a subwoofer. There are speakers that can create accurate midbass but will never bloat the bass like most factory speakers do

Hope this helps,
Zach

stangman67

100 watt RMSx4 will be plenty. I personally would only amp the front speakers and leave the rears on HU power, but that is personal preference. I would also advise to think about installing a simple sub stage if you really are looking for bass performance. A single 10" sealed will satisfy most

ngv1515

You are correct, a 10” sub will be good. Now that I have a better idea, I will get the 4 channel amp and see how everything sounds before I install the sub. I’m also planning to put some sound deaden. I work on Audi’s and I’m used to see lots of sound deaden in doors and panels which keeps out road noise out of the car and helps sound quality but when I took this Civic’s Door panel out I laughed lol. I’ll probably post some pics here. The people at Crutchfield told me to open a 1” hole at the bottom of the speaker baffles to help with the bass but if I’m going to put a sub I don’t know if I should do that.

FestYboy

Chuck the "baffles", the Polks (as with most car audio speakers) are designed for infinite baffle install. Having the foam cups behind the speakers sucks up all the back wave energy.

I'll agree with @stangman67 , concentrate on the front speakers for external amplification, and do research on you amp! If you have a model in mind, look it up on YouTube to see how it stacks up against a dyno. I like "big D-wiz's" channel. He pulls no punches. If you're after sound damping, start in the rear and work forward.

Clipdat

Removing the rubbers and going with a 50-75w x4 or even just a 50x2 for the fronts only will go a long way toward improving their performance. There's a huge difference in 18w/channel coming from a head unit, and 50w of clean power coming from a dedicated A/B amp.

ngv1515

I will cut out the baffles and check out the YouTube channel.

Clipdat

@nbrowser I get that the foam/rubber baffle is to protect the back of the woofer from water exposure that it'll see in the area inbetween the door. It seems like this is at the expense of dynamics and low frequency response though, due to it stifling the ability for the woofer to move air around as it normally would.

Is there another way to protect the backside of the woofer from the elements, while at the same time not affecting it's acoustic performance?

ngv1515

Ok... I cut some of the foam. I left some of the top to protected from water since the Water seals are old and don’t work that well.

The result is outstanding!!! Now the speaker moves like it should. The mids and lows are good. Whole door rattles now LOL

ngv1515

stangman67

If you really want to improve the sound, seal the door. This creates finite space to act as the enclosure. I did this to a 95 so if I had in college with a bunch of deadened and the results were fantastic

Clipdat

Even in newer cars, water gets inbetween the seal at the bottom of the window and drips down into the door cavity.

nbrowser wrote: »

If the seals on the door are working correctly, you shouldn't have issues with water hitting the back of the woofer.

dalylaleahthor

From my understanding the rms has always been per speaker. I have always used an amp that put out more rms the speaker's rating. Better to have more power than needed then needing the power and not have it.

verb

Clipdat wrote: »

Even in newer cars, water gets inbetween the seal at the bottom of the window and drips down into the door cavity.

nbrowser wrote: »

If the seals on the door are working correctly, you shouldn't have issues with water hitting the back of the woofer.

@Clipdat is correct. It's actually a water barrier, not a seal. All doors leak some water at times. The barriers are designed to manage the water and keep it away from critical components originally designed for the car, not new ones added later.

ngv1515

ngv1515

dalylaleahthor wrote: »

From my understanding the rms has always been per speaker. I have always used an amp that put out more rms the speaker's rating. Better to have more power than needed then needing the power and not have it.

I agree with you but this car doesn’t have a lot of space and all 4x100 rms amps are big. I’m thinking of putting 4 channel amp under pass seat and one mono amp under driver’s seat and I still don’t know where to put the power cap yet.

FestYboy

http://soundstream.com/product/pn4-520d/
http://soundstream.com/product/pn1-650d/

ngv1515

DSkip wrote: »

Don't get a cap. It's a waste.

Really? I put one in my car when I was in high school many moons ago and it worked. Before cap i had strobe headlights lol

Clipdat

I've never used one, but I think the thought is that the battery is already a big capacitor. So if the battery/charging system isn't up to snuff, then adding a capacitor on top of that isn't going to help.

I think the old suggestion used to be put money toward "the big three", instead of just adding a cap. The big three being Battery, Alternator, and bigger/better grounding cables.

https://www.crutchfield.com/S-m1taXotSLvm/learn/learningcenter/car/stereo_power_ups.html

ngv1515 wrote: »

Really? I put one in my car when I was in high school many moons ago and it worked. Before cap i had strobe headlights lol

ngv1515

Clipdat wrote: »

I've never used one, but I think the thought is that the battery is already a big capacitor. So if the battery/charging system isn't up to snuff, then adding a capacitor on top of that isn't going to help.

I think the old suggestion used to be put money toward "the big three", instead of just adding a cap. The big three being Battery, Alternator, and bigger/better grounding cables.

Yes you guys are right. I can’t do the alternator yet because car will get a engine swap, I’ll have to wait. Battery is in the list, Optima, along with wires. I want to take interior apart ONCE. Sound deaden, wiring, amp install, etc. I’ll wait on the power cap, it may not need it.

Clipdat

h22a swap?

FestYboy

J35.... Go big or don't bother

Nightfall

K series swap and turbo.

ngv1515

Lol no need for over kill. B20B is the plan. Just enough to keep up with traffic.

ngv1515

ngv1515

Told my friends about the project and one gave me an amp and another one a box with 2 12”s the amp was on the floor in my friends garage... hasn’t been used for years and box was sitting in the attic for years too. They’re not high quality but it would do the job.

Notice some difference after putting sound deadening on the right rear. I can hear the right rear speaker better but I ran out of it so I’ll add more later.

ngv1515

FestYboy

Thank your friend for the box and 12s, that's a nice gesture, but if I were in your shoes, I'd use just one in a better box, or trade it off for an 8 or 10 in a transmission line configuration. 2 12s will be too much for the cabin size.

ngv1515

FestYboy wrote: »

Thank your friend for the box and 12s, that's a nice gesture, but if I were in your shoes, I'd use just one in a better box, or trade it off for an 8 or 10 in a transmission line configuration. 2 12s will be too much for the cabin size.

Yeah, it is a little loud but at the same time not very clear and takes up 80% of the trunk space. I just lower the Sub volume from the radio. The subwoofer brand is “Vision” never heard of it and it looks old. I’ll take a picture of it soon.

mlistens03

Listen dude, you already have too many subs for your car, so you should go whole hog for bass head and source... I dunno, 10 more? Then you could blow the windows out at stop lights

ken brydson

JasperRichten reported