Originally Posted by Omnipotent Octopus

When i replaced my speakers with aftermarket, I lost the stock bass too. I never thought the stockers were that good untill I replaced them (the bass that is). I gained better highs though. I have subs so losing the bass wasn't a problem. If you want good aftermarket bass you should probably look into getting a component system. I just checked out the specs on your speakers and their similar to mine. You just cant get bass out of regular 2 way 5 1/2" speakers.

These are what you would want....the speaker is actually the woofer and the tweeters play all the higher notes that the 5 1/2's wont.
http://www.crutchfield.com/p_107DXI5...50.html?tp=106

Originally Posted by Basslicks

What it sounds like to me is that even though your head unit may be amplified, it is not supplying enough power for the speakers to run properly. Purchase an aftermarket amplifier. If you plan on eventually replacing all of the speakers, spring for a 4 channel amplifier. I have a 400w sony 4 channel amp (100w peak per channel). This will supply more power for your speakers to pull from. If there is not enough power at the source for your speakers to run off of, they will be power starved and will not run right. Adding crossovers, MDF rings, baffles, or anything else won't do anything if there's not enough power going to the speakers. You're right in that your factory speakers have a higher ohm rating, however they are also designed to operate off of a lower RMS wattage rating, therefore when these speakers are paired with the factory HU, they sound OK... when you upgraded to the aftermarket HU, did you notice that the sound quality increased? That's because the speakers had more power to draw from. Even though, they really didin't need it, there is more than enough power for them to pull from.

Hope this information helps... I'm pretty tired so I don't know if I'm explaining it in a way that makes sense.

Originally Posted by macgyver35

Again, this is one of those misconceptions that has been propagated by the car stereo industry.

On a given speaker, a 2 ohm or 4 ohm version will "sound" the same. One will not sound better than another, necessarily. Some 2 ohm setups will be marginally louder, with the amp putting out more power in 2 ohm configuration, but the increase is usually negligible except in enormous 4000+ watt systems utilizing 4 or more subs. Refer to my previous post on how much of a power increase you have to have just to get a 3.1 decibel increase in volume. The sound is produced by the cone and it's movement/response speed, not by the nominal electrical resistance of its voicecoil. However, the VOLUME will be different at a given power input between 2 ohm and 4 ohm versions of the same speaker.

The more resistance a voicecoil has (higher ohms) the more the cone will move in response to a given power input. So, for quick and dirty reference, you get greater movement at a given power level from a 4 ohm speaker than a 2 ohm, all things being equal. On a side note, I won't go into detail here, but the ohm rating is nominal and not constant. It changes as the voicecoil moves in relation to the magnet.

Anyway, it's important to match your ohm rating on your speaker to that of the device powering it. If you are powering it directly from an aftermarket car stereo, that will be 4 ohms (some factory systems use 6 or 8 ohm setups as this reduces power draw and allows use of smaller gauge wiring). If you are powering it through an aftermarket amplifier, you could go with a 4 ohms or 2 ohms speaker depending on what the amplifier is rated for. Putting a 2 ohm speaker on a 4 ohm amp could burn out the amp once driven to higher volume (I.E higher power demands on the amp).

If you are just going to have one sub, stick to 4 ohm. It will produce more volume at lower power levels than a 2 ohm, which means you don't need as powerful an amp, and you won't need as heavy gauge a wire to power the amp. You'll save money in the long run (cheaper amp and wiring), and you won't notice much, if any, difference in volume or sound quality. Generally speaking, you'll get the same volume out of a 4 ohm setup at 500 watts, as you will out of a 2 ohm setup at 1000 watts, assuming use of a single sub.

There are some decibel benefits to using multiple 2 ohm subs wired in series as pairs (creating a 4 ohm load) and each pair attached to a channel of a 4 ohm amp, as you gain a few decibels with each added sub sharing a channel, but we'll save that for far more involved systems. Imagine (8) 2 ohm subs, wired in series as pairs, and each pair attached to one channel of a 4 channel amp. You know, those crazy loud, annoying as hell systems that will pop the eardrums of any person in a 1/4 mile radius.

If you are going to run two subs, either use a two channel amp with a sub on each 4 ohm channel, or buy two 2 ohm subs and wire them in series (creating a 4 ohm load) an hook them to a single channel (or bridged 2 channels) of a 4 ohm rated amp.

Originally Posted by macgyver35

Power ratings on subs are just indications of how much power they can handle, not how much power they need. It can be given in peak, RMS, or both. Just because you have a 1000 watt capable sub does NOT mean you need an amp anywhere near that kind of power for it to sound good. The car stereo industry makes a habit of taking advantage of people that haven't studied the physics behind sound and who don't understand the math. They make up a lot of jargon that sounds impressive, but it is sometimes misleading or flat-out wrong.

Something to keep in mind...
You have to double the amplifier power to get a 3.1 decibel increase in volume. So, assuming the same speaker is used, an amp pumping 1000 watts to a sub will only be 3.1 decibels louder than an amp pumping out 500 watts.

Also, you need a 10 decibel (or over 3 fold doubling of power) increase to gain a perceived (by your ears) doubling of volume. I.E 30db sounds twice as loud as 20db. 80 db sounds twice as loud as 70db. For example, if a sub puts out 100db at 50 watts, I'd need to put over 400 watts into it to get 110db out of it So, using these two mathematical rules of the physics of sound, a 1000 watt amp will not sound twice as loud as a 500 watt amp. It will sound roughly 33% louder, for quick and dirty math. Look at the subs rating at 1 watt/ m1 meter (usually indicated as SPL). It will usually be in the 85db-91db range.

Let's use a speaker rated at 90db SPL @ 1 watt / 1 meter and apply the 3.1 db for each doubling of power rule.

1 watt = 90db
2 watts = 93.1db
4 watts = 96.2db
8 watts = 99.3db
16 watts = 102.4db
32 watts = 105.5db
64 watts = 108.6db
128 watts = 111.7db
256 watts = 114.8db
512 watts - 117.9db
1024 watts = 121db This sub is about 8 times louder at 1024 watts as it is at 1 watt (perceived volume doubles with each 10db increase. 90>100 = 2 times, 100>110 = 4 times, 110>120 = 8 times).

Another example: SPL is 85db

1 watt = 85db
2 watts = 88.1db
4 watts = 91.2db
8 watts = 94.3db
16 watts = 97.4db
32 watts = 100.5db
64 watts = 103.6db
128 watts = 106.7db
256 watts = 109.8db
512 watts = 112.9db
1024 watts = 116db
2048 watts = 119.1db
4096 watts = 122.2db

As you can see from the examples above, the first sub (more efficient) puts out more sound at 512 watts than the second sub does at 1024 watts! It pays to buy efficient subs!! We'd also have to pump over 4000 watts into the second sub to get it to top what the first sub can do at 1024 watts!!


You can substitute your sub or speaker's 1 watt / 1 meter rating in at first position in the above lists and add 3.1db to each doubling of power to get how much sound you'll get out of it at various wattage levels.

Yes, I know there are other variables like variations of sound in the source material, acoustic gain depending on vehicle and sub placement, etc. But for any given sub/box/vehicle/positioning configuration, these rules hold true.

Again, the math and physics behind sound is far more long and complex than what I've described here. I tried to distill down some of the basic concepts and most pertinent information the average person would use when selecting a sub or planning a system. Hope this helps some of you.

Originally Posted by mr white

More power doesn't necessarily mean better sound. The stock speakers sound better with an aftermarket hu because the source of the music is better. It can produce a clearer, cleaner sound.
In this case an amplifier likely will help him. I asked about his crossovers because many people forget about those and it is free to check. If he amplifies his speakers, and they don't have a proper mounting surface, they will still sound like poo, which is why I also said he might need to mount them to and mdf ring after he amplifies them. If he listened to a pair in the store (that were amplified) and they sound the same as his now, it is pointless to buy an amp, as that means these speakers aren't what the op is looking for.

Originally Posted by macgyver35

Okay, a few bits of info from a guy that spent his younger years installing car stereos and currently owns audiophile grade home theater equipment...

Your Polks and your head unit are matched in terms of nominal impedance (4 ohms) so you don't have any issues there. I also don't believe they are not getting enough power. The way sound from speakers works is that you get a 3.1 decibel increase in sound each time you double the power to it. And the way that sound works in general is that you need a 10 decibel increase to have a perceived doubling of sound volume. In other words, if you start with 18 watts to speaker, you'd have to bump up to roughly 225 watts per channel to get those speakers to double their sound output from what they produce at 18 watts. Believe it or not, most of your listening done at "normal" volume levels of around 70 decibels is produced when the speakers are only getting less than 1 watt of power. Even "loud" levels of 90 decibels are produced with just a few watts of power. For reference, being at a rock concert 50 feet from the stage is about 115 decibels.





What you are suffering from is a small cone area, tighter control of cone movement with a better speaker, and a large empty volume of air that exists behind the headliner, which is not optimized for your new speakers. The stock speakers produce more low notes because the smaller magnet and lighter cone allows the cone to move more freely, which helps with the VOLUME of lower frequencies, but not the QUALITY of lower frequencies. The bass is there, but it's loose and muddy.

Most 5.25" speaker don't put out any appreciable bass or mid bass below 100 Hz. With 6.5", you'll typically get down to around 65 or 70 hz, but how well that bass projects is hugely dependent on enclosure dynamics.

Here are some previous posts and info about my system, which sounds great by the way, that may help you a bit.

https://www.cherokeeforum.com/f67/re...nstall-133158/

Dual XDMAR6720 CD/MP3 SD Bluetooth Head unit
Dual XPE2700 amp mounted under front passenger seat for sub
Polk DB651 6.5" Speakers in doors
Polk DB521 5.25" speakers in rear headliner
Kicker 6.5" CompVT sub mounted in self-built enclosure in rear cubby.

My sub install creates ZERO loss in rear cargo area floor space, and looks about as close to "factory" as anything I've seen.

Thanks to Amazon, I only spent about $450 for the whole system.

Originally Posted by Basslicks

What you are saying is correct, but you neglected to address the power issue which is what I was getting at. Yes, crossovers are important, yes mounting surface is important, but if your speakers are underpowered, it is a mute point.... as is backed up by what Macguyver said:

Originally Posted by Basslicks

hahaha... I didn't even catch that... MUTE=MOOT

Originally Posted by Omnipotent Octopus

You just cant get bass out of regular 2 way 5 1/2" speakers.

These are what you would want....the speaker is actually the woofer and the tweeters play all the higher notes that the 5 1/2's wont.
http://www.crutchfield.com/p_107DXI5...50.html?tp=106