how can i get fuller bass range

seems like some real pros runnin behind the scenes here. finally someone might be able to help me.

ive got an 04 monte carlo with 2 alpine type r 15s runnin off a pair of hifonics brutus 1200 watt amps. i got them wired to 2 ohms each on the 1 ohm stable amps, and a clarion crossover. my box is sealed and, sadly, i do not kno the size of it (which is probrably VERY important to my question. i will look the dimensions up if i get any responses).

how can bring out higher bass tones?

i finally chose the 15s after much trial and error, seeing as i could not get a deep hard bass sound outta 12s in my trunk.(ive tried pioneer 3k watts sealed, mtx 7500 sealed and ported, kicker l7 sealed and ported to be exact).  the 15s SLAM. my problem is i seem to be getting super high energy from the 20 to 35hz range (estimated, not metered) which i LOVE... but  everything over 45 or 50 hz or so sounds very weak. ive been workin on car audio for years and ive always recomended sealed box in general based on my love for deep low bass, but never have i encountered such a steep cutoff of higher toned bass.

ive tried over and over adjusting the xover levels on the amps, the crossover, and the bass boost, but it seems like the accoustics for the sound just isnt there.

do i really need to find a ported box? is there something im overlooking? im not lookin forward to the lack of trunk space. and if i DO get a ported box, how should it be built to match my love for low bass AND still be able to hum the higher notes?

basically ive tried all the settings. radio, external crossover, amplifiier crossover. with all them on high, i still dont get the response. i mean, it makes it a LIL better, but it seems like it draws a whole lot of extra energy.  no my amps do not have any subsonic filters (which im upset about).

the hpf on my car speakers is set relatively high (prolly 150 or so), i dont like a lot of bass going thru them. as for the woofers, i got my estimated signals via usac bass test tones. i got one for every 10 hz, 20 to 100, and also a 20 khz to 20 hz signal test. the 20 , 30 and 40 sound great, the others, as i mentioned, sound weak. granted louder than my car speakers but u can feel the pressure get released after 40 to 50 hz or so.

ive been in sounds for about 10 years since i had 2 10's hooked up in my room via converter box. ive done hundereds of installs. im not NEW but there are some things i never learned by the book. for instance ive never learned how to build or tune a box. i always just bought one from the sound shop and hoped i liked the way it sounded.

thanks for all the help, and even reading any of this. sorry im not quite so technical, im a hands on person. if i could, i would sit u in my car and play u a song so u could see just what im talkin about.

ok i jus went and ran the sound tests again... 20 thru 40 sound FANTASTIC. the 50 is faltering, by the time it gets to 60 to 80 its more of a buzz than anything. the part that worries me is the woofer is really vibrating, as if its getting the wattage, but not producing the sound.

all xrossovers set to high (200 or so) on amp and passive,  radio sub output has been on thru (i thought i had this turned on, but i guess not).

what happens is, the 50 to maybe 100 hz actually play, but the volume at which they play levels off at a point. the lower tones play MUCH louder, and can be overbearing at times. dont get me wrong, i LOVE this earth shattering low bass response, but i wanna kno why its costing me so much of my higher bass.

i am an idiot wrote:

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Does your radio have an adjustable crossover for the Sub Output?

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edelbrockboy, you've got i am an idiot and DYohn looking out for your interests here.  Listen to them, answer their questions and you will get your sound system up and running the way it should be.

Don't underestimate the importance of the blending of sound between the sub and the midwoofers.  That's where the power and significance of the 60 Hz to 120 Hz range comes from, and that's an entire octave.  If a change to your mids is in order at the end of it all, then what it is, it is.  But for the time being, stay tuned and keep up with your thread responses.

 Please.

sorry i didnt respond earlier. my net copped out on me for a bit before work. my box is approx 1.25x1.15x1.3... i think thats almost 2 cubic feet (which shoudl be very small for a 15inch box). im PRETTY sure its my box thats the issue. i wouldve assumed that with a smaller box id get better high response. my bass IS tight and clean which is a plus, but...

as far as my filters, i got factory speakers and yes the hpf on the mids is running straight thru, but its not the 80 to 120 gap im worried of, its the 50 to 80. my punch bass, assuming u are referring the the kick drum chest pound feeling, is practically none (in comparison to the lower notes). the bass runs extra low (36 hz sounds the most beautiful) but if i tune it to highs, they come out muddy and sloppy. its this last statement that leads me to belive my box is a problem. its as if the amp is sending the wattage and the high bass signal to the woofers, and they are playing it, but it jus doesnt sound good. i can turn 60 hz up and theres definitely an excursion but the sound doesnt match the speaker.

again thanks for even reading this, much less responding in such a helpful manner.

the dimensions i gave were for each chamber. as for the radio, it does have a subwoofer output with a lpf on it but i have the filter running all sound thru. kdc-mp435u  may be the model number, if not then it would be a predecessor of this unit.i can get u the exact number later, but if u are only wondering of the lpf, i do have it turned off.

1. yes my radio has a sub output level with a LPF feature, which is set to through, which means, basically, off.

2. sub amps have their LPF set to a high setting, i wanna say 120 offhand. the crossover between the head unit and amp is set to about 50 hz. i have tried this setup with and without use of the extra active crossover, and with the active crossover set to its highest (200hz) setting.

3. im not running an amp to the rest of the car speakers, they work via the radio's amplifier. the rear deck's filter is running thru (no HPF set), and the fronts have 180hz HPF on.

im not having an issue with the regular speakers. they sound fine, and actually my entire system sounds pretty good to the average listener. im simply wondering why i dont really get the sound pressure levels at the 50 to 80 hz range.

edelbrockboy wrote:

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im simply wondering why i dont really get the sound pressure levels at the 50 to 80 hz range.

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Because you either have your crossovers set incorrectly (which you certainly do) or you have a subwoofer enclosure that is incorrectly designed for the speakers you're using (which you may) or you have main woofers that are ineffective or out of phase (which you might) or you have acoustic issues inside the vehicle that are emphasizing the sub bass while sucking out the bass frequencies (which is likely.)  Or any combination of all the above.

The first thing I would recommend is this:

1) Remove any external crossovers from the system
2) Set the LPF for your subwoofer at the exact same frequency as the HPF for your front mains.  I suggest trying 100Hz.
3) Ensure your subwoofers are in phase with your main woofers and that all main woofers are in phase
4) Adjust your amplifier gain properly to achieve the system balance you desire.

1. done. no avail.

2. done. no avail.

3. done. no avail. how bout hooking up ONE woofer only, and testing it with ALL other speakers off. same response. i hadnt really thought of my main speakers being out of phase with the woofers. that was a good point, but not the problem.

perhaps i will try to video the difference in sound between my car and my roomate's truck and post it on youtube and link it here. i kno the sound quallity will be terrible, but u should be able to hear what i mean if i listed to similar tones in both cars. ill give it a shot. if it seems useful to post it, i will.

my point is this is clearly not a crossover frequency problem. theres a fair chance i DO have my crossovers set wrong. i dont have a meter to properly adjust every octave to make sure they are equal, i just go by ear. your second and fourth points sound like the responses i was looking for help on.

im almost positive i need a box thats tuned differently. ive stated that im bad with boxes, and im aware that boxes have everything to do with sound. im wondering is there a sealed box i can get thats good on high bass, or a ported box i can get thats good on low bass.

ive also stated that 12 inch cones didnt seem to do the trick. i tried at least 5 different brands before i put 15s in and realized that was what i needed. i think this is due to the accoustics of the car. i have a fairly large trunk. interestingly enough, when i tried the 12 inch solo baric L7s, they sounded ok. long story short, i let my roomate borrow the woofers. in his blazer, the L7s EXCELLED.  every sound range was touched appropriately. he doesnt have the lows as strong as i have, but all around his bass is much more full. ive installed a brutus 1500 watt amp for him, much similar to my twin 1200 watt brutus. it sounded SO much better in his truck that i decided to let him keep the woofers, and a few months later we called it even after he gave me an all around brake job.

more so i was actually hoping to not only hear from an expert (and you guys seem VERY knowledgable), but perhaps find someone who had the same car as me and tell me a bit about thier setup.

again thanks for all help given. its greatly appreciated.