# New system with good stuff. So so sound. Why?



## CaptainStereo (Jan 22, 2012)

Dear fellow enthusiasts, I have what I feel is a pretty good system from a hardware standpoint. It was installed competently. But I find the sound fairly underwhelming. Here's what I have...

Front coaxials: JL Audio C5-650
Rear coaxials: JL Audio C2-650
Subwoofer: JL Audio ProWedge W6V2 sealed subwoofer
Amplifier: JL Audio HD900/5
Head unit: Kenwood Excelon KDC-X995

All installed with dynamat in the doors of a 1997 Nissan Maxima. 

To get this out of the way, I have kids who enjoy music, so I was always going to get rear speakers. I know many advocate not using rear speakers. I want my young children to enjoy music, and I want them to be able to hear it. So there's that 

My issue is one I hear about often, and that is a surprising lack of mid-bass weight and heft. It seems pretty 'boom-tizz'. I do have the front doors dynamated. 

The other issue is one of perceived resolution. I use my iPhone as my main source and I import all my music using Apple Lossless. When I compare a track from the iPhone to the same track via the original CD, there is no real difference. I have two friends who both were pretty adamant about using coaxials in the front as they feel the benefit of having both drivers wave launch originating from the exact same spot outweighs the potential benefit of components (and even JL admits there is no quality difference between the coax's and components in their C5 range as they cost exactly the same and both use an outboard crossover). There is exactly 8 3/4" between the bottom of my car's stock Bose (shudder) tweeter location and the top of my car's stock mid-woofer location. 

The sealed sub box is anchored down and not floating loose in the trunk. 

The sensitivity of the HD900/5 amp was set up with professional equipment by a superb installer. 

I have all the b.s. settings in the head unit turned off (ie-no bass boost, no highway sound, no "supreme +", no car size compensation, etc.).

Ideas or tips?


----------



## thomasluke (Jun 10, 2011)

Are your doors sealed or just deadened?
You really have to seal up the doors and seperate the front and back wave of the driver.
Also take a look at your cross over settings or post a few pics of the settings so someone can help you adjust them to your taste or take it back to the shop and them tune it while you can hear it then make a more adjustments if needed.


----------



## CaptainStereo (Jan 22, 2012)

Thank you. Yeah, I've heard you really need to seal up all those holes in the door. As for front and rear wave of the front speaker drivers, is there a specific back box or baffle you would recommend?



thomasluke said:


> Are your doors sealed or just deadened?
> You really have to seal up the doors and seperate the front and back wave of the driver.
> Also take a look at your cross over settings or post a few pics of the settings so someone can help you adjust them to your taste or take it back to the shop and them tune it while you can hear it then make a more adjustments if needed.


----------



## thomasluke (Jun 10, 2011)

CaptainStereo said:


> Thank you. Yeah, I've heard you really need to seal up all those holes in the door. As for front and rear wave of the front speaker drivers, is there a specific back box or baffle you would recommend?


By sealing the doors you are eliminating the interactions between the two.
Some will tell you to a deflective pad to mount behind the driver and it may but to what extent. well thats quite depatable.
The ost effective effective things to do are...... well, just read thishttp://www.sounddeadenershowdown.com/cgi-bin/index.cgi.
Thats more details than i'm willing to type right now.:laugh:
All that isnt going to do anything though if your installer has a hpf of like 120 hertzs though. 
Oh, and while your going through all that trouble make sure that the baffle that is mounted to the door that the drivers mounted on is very ridged and dampened as well.


----------



## nubz69 (Aug 27, 2005)

If you are going to open up your doors I would also recomend you install some MDF spacers between your speakers and your door. The MDF helps add mass which make a much more solid mount for the driver. This will help out your midbass a lot. 

Since you have an iphone, I would also download a free RTA program (JL audio has one on their app). Use this to tune your EQ a bit on your head unit. Then set your time alignment. Chances are that your system just needs a bit of tweeking.


----------



## CaptainStereo (Jan 22, 2012)

Thank you for the excellent suggestions. I can tell you about the amp crossover settings. I don't use the xover settings in the head unit. I have the front and rear speakers crossed over at about 50Hz with a 24db slope. I have the sub crossed over at about 65Hz, also with a 24db slope. Strangely, as a test, I defeated the crossover of the main speakers so that they were running full range and it didn't seem to make much difference. 



thomasluke said:


> By sealing the doors you are eliminating the interactions between the two.
> Some will tell you to a deflective pad to mount behind the driver and it may but to what extent. well thats quite depatable.
> The ost effective effective things to do are...... well, just read thishttp://www.sounddeadenershowdown.com/cgi-bin/index.cgi.
> Thats more details than i'm willing to type right now.:laugh:
> ...


----------



## joemk69 (Dec 3, 2010)

CaptainStereo said:


> Thank you for the excellent suggestions. I can tell you about the amp crossover settings. I don't use the xover settings in the head unit. I have the front and rear speakers crossed over at about 50Hz with a 24db slope. I have the sub crossed over at about 65Hz, also with a 24db slope. Strangely, as a test, I defeated the crossover of the main speakers so that they were running full range and it didn't seem to make much difference.


Bump the x overs up to 80 hz 12db on both the front and rear speakers and you will be able to crank the volume a little bit more. 80 hz 12db on the sub as well. Like stated before seal your doors up as well as possible. With out sealing up the doors the front and rear waves are just canceling out your midbass


----------



## CaptainStereo (Jan 22, 2012)

I'll try it, thank you. Anyone have any opinions on the merits of equal quality coaxials up front versus components?



joemk69 said:


> Bump the x overs up to 80 hz 12db on both the front and rear speakers and you will be able to crank the volume a little bit more. 80 hz 12db on the sub as well. Like stated before seal your doors up as well as possible. With out sealing up the doors the front and rear waves are just canceling out your midbass


----------



## thomasluke (Jun 10, 2011)

CaptainStereo said:


> I'll try it, thank you. Anyone have any opinions on the merits of equal quality coaxials up front versus components?


They look like same have the same specs but i've never heard the coax version of the c5's so can't say if they will sound.
But they do appear to be the exact same.


----------



## dietDrThunder (Nov 4, 2010)

I am in exactly the same boat as you are (even the rear fill w/ kids). I'm about to post this same exact thread (essentially). I think it might be a really good opportunity for us to compare/contrast, get ideas, etc.

I was going to post up in your thread, but I think the suggestions and replies might get to be too confusing.

Let's see who can get satisfactory sound first!


----------



## CaptainStereo (Jan 22, 2012)

I love it. Sounds good (no pun intended).



dietDrThunder said:


> I am in exactly the same boat as you are (even the rear fill w/ kids). I'm about to post this same exact thread (essentially). I think it might be a really good opportunity for us to compare/contrast, get ideas, etc.
> 
> I was going to post up in your thread, but I think the suggestions and replies might get to be too confusing.
> 
> Let's see who can get satisfactory sound first!


----------



## Danometal (Nov 16, 2009)

Another angle, IMO:

In a sealed box, you can get away with a high Xover point (in many subs I've tried). Try crossing your sub at like 100 hz, and make sure to time delay all your mids and highs to the sub. This will add great weight to your midbass.

I'm currently running stock components up front (because they're so clean and composed actually), but they lack midbass. I have my sub crossed @ 110 hz, and the mids and highs passed @ 100 hz. (and my sub is ported to 25 hz!!) After getting the time alignment right (to get rid of most of the localization of the sub), the midbass about snaps your head off. I'm running a JBL P1224 in a big box, and it has quite a bit of output, so that may be a relevant factor in this.

Please note that, if you run a 12 db slope, you might need to swap the phase on your sub to keep the midbass up.


----------



## Wattser93 (Mar 12, 2010)

Danometal said:


> Another angle, IMO:
> 
> In a sealed box, you can get away with a high Xover point (in many subs I've tried). Try crossing your sub at like 100 hz, and make sure to time delay all your mids and highs to the sub. This will add great weight to your midbass.
> 
> ...


Interesting that you say that. I've always been told by people that a ported box can't play much more than an octave above tuning frequency, and that a sealed box is much better for playing higher. I just got done installing my system yesterday, my box is tuned to 32Hz (and is also large like yours), and I found that with proper level matching and time alignment, my sub does just fine to 80Hz, and I'm thinking about bringing the crossover point up just a bit for some more emphasis in the mid bass region.


----------



## avanti1960 (Sep 24, 2011)

there may be nothing wrong with your system. i recently had similar issues with my system in a 2011 rav4- very thin sounding despite good hardware and door treatments. i have the same amp (900 HD) but am running 4 sets of focal component speakers and a JL 12W3v3 ported to 25 Hz. my receiver does not have time alignment. 

my 6.5 drivers took a long time to break in and start playing more bass- i would say almost a month, playing about 90 minutes a day or so. 

also, i find on cold weather days (anything below 40 degrees) the bass output is really low unless i drive around for about an hour and the door speakers and sub finally warm up- i find that i have to turn down the sub volume after they warm up and cut the EQ back on the 250 hz band. 

however, after recently auditioning those JL C5 and C2 speakers, my ears as well as my very trusted audio advisor told me to stay away from those speakers- they were very flat and weak, especially the C2s. In my case I needed the rear doors to have decent mid bass drivers- my rear doors are actually better bass enclosures than my front doors. 

give them some time to break in (if you haven't already) and make sure they are thoroughly warmed up if your weather is cold before you judge their performance. If after that they are still lacking, I would recommend you upgrade the 6.5 inch drivers. GOOD LUCK!


----------



## Danometal (Nov 16, 2009)

Wattser93 said:


> Interesting that you say that. I've always been told by people that a ported box can't play much more than an octave above tuning frequency, and that a sealed box is much better for playing higher. I just got done installing my system yesterday, my box is tuned to 32Hz (and is also large like yours), and I found that with proper level matching and time alignment, my sub does just fine to 80Hz, and I'm thinking about bringing the crossover point up just a bit for some more emphasis in the mid bass region.


Thing thing with ported boxes I've discovered is that they play just as high as most other sub configurations (I mean, it's just a driver in a box, and we decide what signal it gets). The difference I've noticed is the perceived response, which is congruent with the behavior of the response curve itself. 

What I mean is that a high peak in the response (like most ported configurations exhibit) causes a perceived steep rolloff higher up in the response curve, which makes us think "ported boxes won't hit up high," but in reality is not a rolloff at all. It's a loss of a peak. So, if your sub is slamming at 45 hz because of a 4 - 6 db peak, a 80 - 100 hz tone is going to sound muted because it has a zero db peak in that range. And, peaks muddy up the response anyway, so most people turn the LPF down to cross where the peak loses most of its steam (since apparently that's its most efficient bandwidth).

My solution, which works for me:

Tune a box stupid low (mine is tuned to 25 hz) so there's no low end rolloff to worry about (and thus no need for a subsonic filter), and the response curve will be nice and flat, and then cross it as high as you feel like, because now there's no ugly peak messing with your head and/or your vehicle's acoustics.

My box slams 20 hz to over 100 hz easy by applying this philosophy, and I'll never go back to high tuned ported, or even sealed (unless space is a priority, but I would most likely just port a smaller sub to have my cake and eat it too)


----------



## CaptainStereo (Jan 22, 2012)

In my case, with a small sealed 10" (Jl's sealed box ProWedge using a W6v2 10" driver) powered by the 500 watt channel of the HD900/5 (which is 100 x 4, 500 x 1), do you have a sense of how high I should cross my sub over?



Danometal said:


> Thing thing with ported boxes I've discovered is that they play just as high as most other sub configurations (I mean, it's just a driver in a box, and we decide what signal it gets). The difference I've noticed is the perceived response, which is congruent with the behavior of the response curve itself.
> 
> What I mean is that a high peak in the response (like most ported configurations exhibit) causes a perceived steep rolloff higher up in the response curve, which makes us think "ported boxes won't hit up high," but in reality is not a rolloff at all. It's a loss of a peak. So, if your sub is slamming at 45 hz because of a 4 - 6 db peak, a 80 - 100 hz tone is going to sound muted because it has a zero db peak in that range. And, peaks muddy up the response anyway, so most people turn the LPF down to cross where the peak loses most of its steam (since apparently that's its most efficient bandwidth).
> 
> ...


----------



## CaptainStereo (Jan 22, 2012)

Can you describe what you did with time alignment to get such mid-bass improvement?



Danometal said:


> Another angle, IMO:
> 
> In a sealed box, you can get away with a high Xover point (in many subs I've tried). Try crossing your sub at like 100 hz, and make sure to time delay all your mids and highs to the sub. This will add great weight to your midbass.
> 
> ...


----------



## Danometal (Nov 16, 2009)

CaptainStereo said:


> Can you describe what you did with time alignment to get such mid-bass improvement?


Before I explain, please note that I don't time align left from right, as I like it to sound the same in either front seat (but I do fade the balance a notch or 2 on the fly to make the driver side less loud if I'm by myself) 

I have an Alpine CDA-117, which has an option to T/A with inches vs. centimeters for the metrics, so I choose the inch. I then figure out the distance between my mids/tweets and my ears, and from my sub to my ears. Then I find the difference between those numbers (mine was 4 to 5 feet, can't remember) Say it's 4 feet; delay the front channels 48 inches. Now the waves from the sub and the waves from the mids/tweets arrive at my ears at the same time.

I have speakers in my rear doors, and they're actually closer to my ears than my front door speakers, so they got delayed more than the fronts accordingly. 

I'm pretty sure your Kenwood has T/A, so I encourage you to play around with it. It's a pretty cool feature. Now I can't live without it lol.


----------



## nubz69 (Aug 27, 2005)

I am a big fan of using the crossovers on the head units over the crossovers over the ones on the amp. They are more accurate, easier to tune and are always at your finger tips. Try defeating your amp crossovers and using just the head unit.


----------



## ZAKOH (Nov 26, 2010)

CaptainStereo said:


> Thank you for the excellent suggestions. I can tell you about the amp crossover settings. I don't use the xover settings in the head unit. I have the front and rear speakers crossed over at about 50Hz with a 24db slope. I have the sub crossed over at about 65Hz, also with a 24db slope. Strangely, as a test, I defeated the crossover of the main speakers so that they were running full range and it didn't seem to make much difference.


Having finally achieved satisfying midbass in my car. I have a bunch of thoughts on this issue..

* You can not tell exactly where the crossover frequency is for the passive crossover. This is why it's much better to use the active crossover on the stereo.

* It's also better to use the active crossover on the stereo because this should not induce a phase shift.

* 50Hz crossover frequency is too low for a 6.5 inch speaker. This might have worked with a high performance speaker designed for good bass (e.g. HAT Clarus), but most 6.5 inch speakers need to use higher high pass frequency. A good rule of thumb is to set the crossover frequency at or above the resonance frequency of the speaker. Unfortunately, most vendors do not publish the T/S specs of the component woofers, but I have seen many tests that show that for the vast majority of 6.5 inch car speakers, the resonance frequency is between 65Hz and 95Hz. I would recommend to set your crossover frequency no lower than 70Hz, and use the sharpest slope you can use (24dB would be good). I prefer to use the sharper crossover slope on midbass because the rolloff induced by the crossover actually starts above the crossover frequency. If you use a shallow slope, your speaker can be down by something like 1dB at say 75Hz even though the crossover frequency is 70Hz. With sharper crossover frequency, the rolloff starts a bit lower, but it will be sharper.

* One of your speaker is out of phase.

* Realize that some speakers just don't have that much of mid bass. 

* Have you considered using equalization? If your equalizer has a band in the 65-90Hz region, consider bumping that by 2-4 dBs. Of course, this will also affect the subwoofer, and I think this is not good (this makes kick drum punch way too strong on some tracks). The way to deal with this is to set your subwoofer crossover frequency a bit lower. In my car I use these settings:

Subwoofer low passed at 50Hz, 18dB slope (12 inch Infinity Kappa)
Speakers are high passed at 70Hz with 24dB slope (Hybrid Audio Imagine, running active)
3dB boost at 65Hz through head unit's equalizer
The front speakers are time aligned with each other to optimize for driver's position.
The subwoofer is wired in phase

The result is great midbass sound without the subwoofer muddying up the sound. This kind of setting might or might not work for other cars and speakers.


----------



## CaptainStereo (Jan 22, 2012)

Interesting suggestion. I would have thought that the crossovers built into a retail $1,200 amp would be better than the ones built into a $380 head unit, but I suppose if nothing else, it's a free experiment. Thanks for the suggestion! Keep 'em coming 



nubz69 said:


> I am a big fan of using the crossovers on the head units over the crossovers over the ones on the amp. They are more accurate, easier to tune and are always at your finger tips. Try defeating your amp crossovers and using just the head unit.


----------



## CaptainStereo (Jan 22, 2012)

I love it. Thank you for the ideas and feedback. 

I did check to make sure everything was set up and in phase, and they are hooked up correctly. 

Per another post-ers suggestion, I do have them crossed over at 80Hz now, with the sub at about 100Hz (it's a sealed 10" JL sub/sub box). I do think I will lower the sub crossover back to between 60-70Hz as it sounds much tighter when crossed over lower. 

I did find however that the 24db crossover slope sounded much better than the 12db one. 12db also seemed to create some phase weirdness, to which I am particularly sensitive. 

I'd love to hear from others as to what they've found when they've defeated their amp crossovers in favor of the head unit's crossovers.




ZAKOH said:


> Having finally achieved satisfying midbass in my car. I have a bunch of thoughts on this issue..
> 
> * You can not tell exactly where the crossover frequency is for the passive crossover. This is why it's much better to use the active crossover on the stereo.
> 
> ...


----------



## rallypoint_1 (Oct 26, 2011)

I had kind of the same thing going on. Pretty good stuff but lacking punchy bass. Ended up being one of the two subs was out of phase and cancelling each other out when played together. Now it sounds great. Also let your speakers break in.


----------



## Danometal (Nov 16, 2009)

ZAKOH said:


> Having finally achieved satisfying midbass in my car. I have a bunch of thoughts on this issue..
> 
> * You can not tell exactly where the crossover frequency is for the passive crossover. This is why it's much better to use the active crossover on the stereo.
> 
> ...


It appears there are vastly different ways to get the midbass snap, but it's good to see different options to get a desired effect. I guess it depends on the equipment and the install. 

My substage is strong for a single budget SQ sub, so its strengths are used to help my much weaker mids (I do have a set of Polk DBs that are not installed yet, and I may or may not choose to amp these crazy stock mids for the fun of it). 

The Imagines have some serious midbass snap by themselves, and so judging by your success, you can use that strength for a fully forward originating bass response whereas the sub just takes care of the subsonics. Good stuff.


----------



## CaptainStereo (Jan 22, 2012)

Thank you. I only have one sub, but I think I definitely need to get more time on the speakers.



rallypoint_1 said:


> I had kind of the same thing going on. Pretty good stuff but lacking punchy bass. Ended up being one of the two subs was out of phase and cancelling each other out when played together. Now it sounds great. Also let your speakers break in.


----------



## chithead (Mar 19, 2008)

I have to agree with the break-in statement above. I used a set of C5-650 components for a while, and they did sound MUCH different after breaking in and loosening up.


----------



## Wattser93 (Mar 12, 2010)

Danometal said:


> Thing thing with ported boxes I've discovered is that they play just as high as most other sub configurations (I mean, it's just a driver in a box, and we decide what signal it gets). The difference I've noticed is the perceived response, which is congruent with the behavior of the response curve itself.
> 
> What I mean is that a high peak in the response (like most ported configurations exhibit) causes a perceived steep rolloff higher up in the response curve, which makes us think "ported boxes won't hit up high," but in reality is not a rolloff at all. It's a loss of a peak. So, if your sub is slamming at 45 hz because of a 4 - 6 db peak, a 80 - 100 hz tone is going to sound muted because it has a zero db peak in that range. And, peaks muddy up the response anyway, so most people turn the LPF down to cross where the peak loses most of its steam (since apparently that's its most efficient bandwidth).
> 
> ...


I tuned mine to 32Hz, because although I'm a big fan of a really clean front stage, imaging, blah blah blah, I also like teeth rattling bass. I tuned to 32Hz so I can get an F3 of 25Hz, but still have the bump in sound so it slams between 30Hz and 50Hz, and then rolls off into a flat response. I like SQ, but I also like slamming bass for dubstep and rap. It takes 1 button press on the HU to adjust the sub level, so it makes it easy to jump between a "bassy" setting for rap and dubstep, and a more "SQ" setting for all other genres.

My front stage is brand new, with less than an hour of play time (and not that loud), but so far I've settled on a 100Hz 24db LPF for the sub, and a 100Hz 12db slope for the front stage, and I'm happy with it. I'm waiting for the speakers to get a month of play time under their belt, I'm assuming the mid bass should get a little better. The lack of mid bass right now is my only complaint, but with some deadening and some break in, I think that I'll be happy with my system. As long as I never listen to a system that sounds better than mine (read: go to any of the DIYMA get togethers), I should be happy with my system. I don't have the budget to spend anymore (too many hobbies).


----------



## ZAKOH (Nov 26, 2010)

Danometal said:


> It appears there are vastly different ways to get the midbass snap, but it's good to see different options to get a desired effect. I guess it depends on the equipment and the install.
> 
> My substage is strong for a single budget SQ sub, so its strengths are used to help my much weaker mids (I do have a set of Polk DBs that are not installed yet, and I may or may not choose to amp these crazy stock mids for the fun of it).
> 
> The Imagines have some serious midbass snap by themselves, and so judging by your success, you can use that strength for a fully forward originating bass response whereas the sub just takes care of the subsonics. Good stuff.


One thing that always drove me crazy about using higher crossover slopes on the subwoofers is badly/inconsistently recorded music. I have a collection of albums of the same rock band, same genre, yet some of it was recorded so differently. With subwoofer low passed at [email protected], I can find a subwoofer level setting that works fine with one album, yet on the next album the kick drum becomes completely gutless, and yet on another album of the same band it's just too much calling for a constant adjustment of the subwoofer volume level depending on album. But reducing the volume of level of subwoofer to calm down the kick drum also reduces the sound of bass guitar which I'd rather leave alone. Typically a car subwoofer has too much headroom in relation to the front stage (power and excursion-wise, and also the cabin gain) and this shows with badly recorded music. With the subwoofer low passed at 50Hz, this effect still exists, but to much lesser degree. Of course the front stage speaker needs to have the power and excursion capability to accept some bass boost in lower midbass and still sound good. I don't know if using a lower low pass filter for subwoofer always necessarily results in the most impressive sound, but this setting certainly helps to achieve a relatively unoffending and transparent sub bass sound.


----------



## Danometal (Nov 16, 2009)

ZAKOH said:


> One thing that always drove me crazy about using higher crossover slopes on the subwoofers is badly/inconsistently recorded music. I have a collection of albums of the same rock band, same genre, yet some of it was recorded so differently. With subwoofer low passed at [email protected], I can find a subwoofer level setting that works fine with one album, yet on the next album the kick drum becomes completely gutless, and yet on another album of the same band it's just too much calling for a constant adjustment of the subwoofer volume level depending on album. But reducing the volume of level of subwoofer to calm down the kick drum also reduces the sound of bass guitar which I'd rather leave alone. Typically a car subwoofer has too much headroom in relation to the front stage (power and excursion-wise, and also the cabin gain) and this shows with badly recorded music. With the subwoofer low passed at 50Hz, this effect still exists, but to much lesser degree. Of course the front stage speaker needs to have the power and excursion capability to accept some bass boost in lower midbass and still sound good. I don't know if using a lower low pass filter for subwoofer always necessarily results in the most impressive sound, but this setting certainly helps to achieve a relatively unoffending and transparent sub bass sound.


Understood. It appears to depend on the listener's listening preferences and music styles. For example, the guy above likes his bass to slam really hard. I do too, but without any peak. I like it to slam equally from 20 hz to the LPF (mine being 110 hz for midbass reinforcement). This creates a situation whereas it's less optimal to split the first 2 octaves between a sub and the mids, as like you say, the sub has a tendency to over power the mids. 

However, when an _exaggerated_ bass response isn't desirable, and the first two octaves need to be mostly level matched to the next octaves higher, the requirements shift in favor of the mids doing most of the work, whereas the sub takes care of only the subsonics vs. the full attack and punch of the music's lower frequencies.

With that said, I do wonder if the OP's lack of midbass might resolve itself to a noticeable extent when his mids loosen up, as he has competent amplifier power on tap.


----------



## avanti1960 (Sep 24, 2011)

i agree with some of the posts above that say to bypass the amplifier crossovers. 
right now i am running this way and am happy- i find i need the control at the head unit- again have some have mentioned to control the bass effects from varying recordings and sources. 
i have the HPF and LPF set at 80z. since most 6.5" drivers are probably 7db down @ 60 hz or so, there is no sense crossing them any lower than 80.

i do run a slight EQ boost @ 100 hz and a slight cut @ 300 hz. sometimes there is just too much upper bass in certain recordings. 

one other thing- use the infrasonic filter on your amp- its preset for 30hz. i found that it tightens up the bass noticeably and seems to have better output as well.


----------



## CaptainStereo (Jan 22, 2012)

Thank you (all) for the great suggestions. I defeated the amps crossovers and engaged the head units crossovers, and that actually seemed to improve resolution and bass response/output. I found that a 70Hz crossover for the front and rears worked best and 70Hz for the sub as well. And yes, with that amplifier (JL HD900/5), the infrasonic filter seems to make a nice difference. 



avanti1960 said:


> i agree with some of the posts above that say to bypass the amplifier crossovers.
> right now i am running this way and am happy- i find i need the control at the head unit- again have some have mentioned to control the bass effects from varying recordings and sources.
> i have the HPF and LPF set at 80z. since most 6.5" drivers are probably 7db down @ 60 hz or so, there is no sense crossing them any lower than 80.
> 
> ...


----------

