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Discussion Starter · #1 ·
Okay, here's the situation: I'm looking for a way to clean up my sound system's quality by working with what I have and possiblly adding a sound processor or EQ. I've found my system to lack in it's mid-bass and mid range (voice) frequencies. It drives me nuts especially when I know how a song is supposed to sound (and my system is glazing over certain frequencies).

Right now I've got a Kicker IX404 running two Polk 10" subs (20Hz to 400Hz) in a sealed small box and a component set upfront (MB quart tweeters/Infinity Kappa woofers and x-over). The IX404's high/low pass is set at 110Hz with heavy gain on the subs and medium gain on the components.
The speakers in the rear (generic 6.5" coaxils) are powered by the bridged JVC deck.

The one step that's cleaned up things a bit was adding bass blockers to the rear speakers (no more buzzing and farting). Now, I need to boost or tune more mid-bass and mid-range (voice) freqencies out of my system. My biggest concern is getting more mid-bass.

I've considered EQ's (the Kicker IQ900 and the Kenwood 5 and 9 band) and sound proccesors. I've also thought of making custom door box's for the infinity woofers . . .and maybe cutting out holes in the rear deck for 6x9's.

Any suggestions to tune this system would be greatly appriciated.
 

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First step I personally would do is lower your low pass x-over setting on your amp from 100hz to about 80hz. This will do two things. It will allow the subs to produce the frequencies it supposed to produce, and not try and produce the upper bass. This will also allow your MB Quartz to see a lower frequency, and that will help in the mid bass region. See how that sounds first. From there, if you need more tuning install an EQ.
 

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LegendHI,

I agree with Chris and G Rahn's comments. Lower the frequency on the sub. I was having the same issues as you were with the midbass/midrange. I have Quartz in my doors, with only a single 10" Alpine R-Type sub. I also wanted to clean up the sound, so this weekend, I purchased an Alpine 11 Band EQ and it ROCKS!!!! It has a 12db/octave crossover (which I am not using) and 11 bands of adjustibility include Alpine's BBE function (kind of like a loud button).



My setup looks like this:

Kenwood KDC X-911 (dead head)
Non-Fading output running the sub amp (Kicker ZR-240), the ZR240 has a crossover module plugged in and I am running it LP at 80HZ with a 24db/Octave crossover point.
Front output connects to the EQ, from EQ to Alpine 3558 4 channel amp.
The alpine stuff runs the quartz and the Kicker runs an Alpine R-Type 10.

Anyway, I am running the Quartz at full range because I've not experienced them bottoming out once, it's amazing (I'm running 85W to each quart speaker). The EQ is cool because now I can add midbass as I please and adjust the rest of the frequencies. WOW, those Quartz were bright without the EQ, but they can be SUPER bright now. I'm still fiddling with the sound, but I like what I hear so far.

Good luck.
 

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Discussion Starter · #4 ·
Thanks for all the replies, this forum never ceases to amaze me with how helpful everyone is:).

Okay, so far, I lowered the x-over point for the subs down to 90Hz and made sure the fronts were @ 90Hz. This helped a little with a clearer bottem end...but still no luck for any mid-bass.

So, I went down to the local car stereo shop and picked up the Kicker IQ900:

. Installation was absolute hell (I replaced my L-trim's built in clock & top storage area with the eq, with drop-in hidable plain-black face) and still being cleaned up, just fyi. SQ is a lot better with much much more detailed voice/mid frequencies.

Once everything was hooked up, I was able to test out each speaker component individually, which showed (to my horror) my Infinity door-mounted woofers are NOT putting out any bass!! I made sure they were running in full range, and they simply can't put any clear bass tones (besides kick-drum "tunks"). I recall that when I installed them, I had to cut the door's original mounting basket to fit the magnets of the Infinity woofers. The end result forced the Infinity's to act as free-air woofers; there's no pressure in back of the speaker cone to create bassy-meaty tones. So, what can I do?

-Get better quality mid-bass speakers? (my Kappa's are two editions old)
-Stuff sound proofing material into the door's cavity?
-Fabricate mid-bass speaker boxes for the doors? (somehow...)

I'm also curious to know if G1 owners have had difficult times with after-market door speakers and making decent bass come out of them. Thanks in advance!
 

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Hey, I was looking at the Kicker KQ5 when I bought the Alpine unit, but decided on the Alpine because it had more bands for adjustment (11 Alpine Vs. 5 Kicker). I knew that the Kicker unit would have a better crossover but I also knew that I wouldn't be using that feature.

I didn' t know you had a G1, that doesn't matter, but your install of the eq sounds sweet. Mine is simply installed below my head unit in the stock location. Are you still using the crossover on your amp? The one on your amp may be okay, but I'd more than bet that the crossover on your eq/crossover is better with better control. Also it will allow you change the frequencies on the fly so that you can "tweak" your system. I would use the crossover on your unit because if memory serves me right, the crossover on the IX404 is built in with a 12db/Octave cut versus 18db/Octave on the unit you just bought and I would also set it down to 80HZ versus the 90, as the bass will still be cleaner. The difference will be a cleaner cutoff, thereby producing a cleaner sound. You may not be able to tell the difference with just your ears, but an RTA (real time analyzer)might be able to help. Does your local audio shop have an RTA that would be willing to hook up to your system? An RTA will allow you see where the spikes and dips are in your system and allow you so smooth out the frequencies.

Also, you said you have Quart tweets and a Polk Midbass. Where do you have each installed? Are the tweets close to the midbass? The tweet should be as close to the midbass as possible. I have some questions:

1. How do you have them wired?
2. In parallell, series?
3. Do you also have a passive crossover installed before the Polk midbass (i.e. are you using one that was supplied with the speaker)? I hope this makes sense, but the way I think you have it installed is this: Head unit to EQ to AMP via RCA cables. From AMP to crossover to Polk midbass via speaker cables. Is this correct? If it is, then you could have an issue.
4. If you have a supplied passive crossover, where is it installed? i.e. where along the line is it installed, and what is it's crossover point? I think you should have atleast one for the quartz as it should see no duty below 1K.

You never want to run 2 crossovers inline with a speaker. If this is the case, then you have 2 options A. disconnect the x-over supplied with the speaker B. do not use the EQ/Amps High pass crossover. The problem that you get is different crossover points, different cutoff points therefore resulting in a mismatched configuration and leaving you in the dark as to where the crossover point really is which eventually results in a sound that you are not looking for.

To me, it sounds as if you are getting the midbass out of the polks. The polks should not produce anything below 90HZ according to the way you hooked them up. At 90HZ and above you'll only get the kick drums and not that low rumbly bass. To improve that response you can A. buy a baffle. The ones that I know of are actually waterproofing units. They actually fit in the speaker location and enclose the entire speaker. They are sealed and therefore provide an enclosure. B. Dynamat the entire door. This can make your entire door a "box" for the midbass.

Also, you said that the Infiniti subs are mounted in a "small" enclosure. How big is the enclosure and what is the recommended airspace for the subs? As rule of thumb, you shoudl follow manufacturer specs on the amount of airspace needed. The more space you provide, the more boomy the base will be, the less space you provide the tighter the bass will be. A sealed enclosure also require some power in order to get the desired bass. How much power do you have running the subs? Does each sub have it's own enclosure (i.e. is there anything separating the airspace).

You also mentioned that you have the gain on the sub section higher than the gain on the mid/high section. This is incorrect as you are using the exact same amp. The gain is for simply telling the amp how much voltage your head unit is supplying to the amp. Since you are running the same amp from the same head unit, both gains should be equal. However, some people use the gain as a volume control which is okay, but could cause distortion out of one section of the amp before the other section. i.e. your bass will distort before your mids/highs which is an incorrect configuration.

Whew, sorry for the long post. If I were there with you, I'd work with you to "tune" your system. There's alot you can do. I'm almost willing to bet that you have everything installed okay, but you just need to tweak some things to get the sound just the way you want it.

Like I said, I had the same issue as you had, but with some tweaking, I fixed all of my issues :D.
 

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Discussion Starter · #6 · (Edited)
Thanks for the thorough reply Sushilicious! Glad to see we're (pretty much) in the same boat here. Okay, to clear some things up:

I turned off the cross-overs on the IX404 to full-range & now the IQ900's crossovers are on. The IQ900 has a continiously adjustable crossover point from 60Hz to 120Hz and sub level from -72?db to +12db. I have the crossover point typically set around 80Hz.

To lay down the system for you: JVC deck's rear RCA output --> IQ900 RCA in --> sub-out L&R, front-out L&R --> IX404 (single is then amplified) --> L&R powered sub signals to each Polk Audio sub, Front L to hi/low-pass passive x-over, Front R to hi/low-pass passive x-over --> Front L hi/low-pass passive x-over splits powered signal to Infinity woofer (in door) and MB quart tweeter (flush mounted foward of door-open handle), Front R hi/low-pass passive x-over splits powered signal to Infinity woofer (in door) and MB quart tweeter (flush mounted foward of door-open handle). Sound pretty standard, right?

The 10" Polk Audio subs only require .66 cubic feet per sub. I (attempted:rolleyes: ) to build the box to Polk's instructions, which was a single inclosure for two 10" subs. The result was an easy to make box that takes up hardly any trunk space, and provides surprisingly tight, punchy, loud bass.

Okay, here are just a couple more questions:
Assuming the gain control on the amp controls how sensitive the amp is to the in-comming signal (hence, it gets louder quicker and distorts quicker) and how the IX404 puts out only 40 watts per channel, I figured I would try and reverse the natural sensitivity of my speakers. The subs need a lot more amperage than the component sets, so I tried to cheat my amp into playing all the speakers at a more balanced level by raising the sensitivity on the sub channels and lowering it on the component channels. The result sounds okay. The system gets damned loud and the bass stays clean (most people don't believe me that I'm only pushing 40 watts per sub until I tell them the amp is a Kicker). BTW, the Polk Audio subs are only the EXII series, so they're rated a high 93db (in other words, they're relatively sensitive subwoofers that don't need a lot of power to get loud).

So, my question is, should I turn the sub's gain controls down and use the sub-control on the IQ900 instead?


Second, the supplied hi/low x-over on the components only splits the signal between the MB quart tweeter and Infinity mid. Hence, its only spliting the high-passed singal from the IQ900 between the two speaker components. Whats wrong with this? (I hope you're not suggesting I get a three-way x-over and running more cables!!! $$$$$$....)

thanks again!! any other ideas welcomed :)

BTW, so far the system is sounding WAY better after tweaking the equalizer. I'm getting a lot thicker of a sound, especially up front, by adjusting the x-over point and sub volume, and the 125Hz-500Hz frequencies. I'll try post pics soon.
 

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It sounds like you have all the tools already, but they just need some more tweaking. I am assuming that when you turn on the sub x-over on the Kicker EQ it also turns on a high pass filter for the front channel. Given this, the passive crossover that you have should be removed (well with caveat which I'll get to). Let me get this straight:

head unit --> EQ -> amp (all via RCA)

amp -> passive crossover -> door speakers

Even with this, I still have some confusion. Does the passive x-over have a single set of +- input terminals and then 2 sets of +- output terminals or is it a 1 to 1 relationship? Who made the crossover--was it supplied by Quart or Polk? I have a few scenarios then:

1. IF the X-Over was supplied by Quartz and is one set of +- in and one set of +- out, this could be the cause of no mid-bass. If this is the case, you need to wire your polks before the crossover and keep the crossover on the Quartz. If the x-over is supplied by Quartz, it is more than likely matched to the tweeter and is probably crossing out all signals below 1Khz, maybe even higher.

2. If the crossover was supplied by Polk and there is one set of +- in and one set of +- out, then you need to remove the crossover completely and let the EQ handle the crossover duties, either that or turn off the crossover on the EQ and let the passive crossover duties. It is virtually never recommended to have 2 crossovers on a single line at the same time as you can get signals crossed. In addition, if this is the case, your tweeter will still need crossover set at a higher frequency than the polk. If your tweet repeatedly receives signals lower than 1Khz, you could damage your tweet. You can do this several ways, a. buy a passive crossover that will handle these duties (more expensive) or b. buy a resister/cap to block the frequencies (I forget which one you need, a competent stereo shop can sell you one), this is the cheaper option.

3. If the crossover is store bought and has a single +- in and 2 sets of +- out, then do this: amp -> split the signal one set to polk, the other to passive crossover, then to quartz tweeter (from the high section of course). I hope I haven't confused you here.

4. The passive crossover is a combo high/low pass crossover, with the lowpass output going to the infinit and the highpass going to the tweet. If this is the case, remove the passive crossover, or just leave the polk ouf of it, and wire it before the crossover. I hope I haven't confused you.

Did you bridge the amp or wire it in stereo for the subs? If bridged did you wire the subs in parallel or in a series? Parallel is when you take R+ L- (depends on how you've bridged your amp) on your amp and wired both the speakers to them, wiring the + terminal on on the amp to both + speaker terminals and the same with the - signal.

Or do you have L +- going to one sub and R+- going to the other sub? If this is the case, then you've wired the subs in stereo. If this is also the case, and you have a single airspace for the sub, then you can have issues. In this situation, the sub is in a push/pull type of environment. Meaning, both subs don't hit at the exact same time. What is the impedance of your subs?

There's still alot more, but I have to run. hit me up with e-mail: [email protected] and we can discuss more, or we can setup a time and I can talk to you on the phone. I'm out of town until next monday, so I can't talk until then.
 
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