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mlo
11-17-2009, 02:32 PM
Vehicle is a 99 OBS Tahoe 4dr. Hypothetically speaking if a nice set of componenets were installed in the front doors would there be any rationale for considering a set of mid-bass drivers in the passenger rear doors over a set of coaxials?

My perception is the front stage can be made plenty bright but I would prefer to have some more depth or fullness to the low and mid range tones. I have read on here that placement is critical for imaging. I do not have any experience in this and am trying to wrap my brain around this. I have always thought the lower frequencies such as mid-bass were less directionally discernable.

Do the mid-bass speakers use a cross-over or do they need to have an amp that has crossover adjustable capability. Again, I have no experience in this field and am simply trying to learn the basics of how these components interact. A couple members have corresponded through pm's and have been very helpfull...do not want to burn them out.

I have read favorable things about the X-65's one here and am wondering if this would be a sufficient addition to my sound stage that would allow me to consider deleting the subwoofer. My listening pleasure would be designed around the front stage though I believe some rear fill is needed because of the size of the vehicle. OEM speaker location is important and well as things being discrete.

TIA for any words of wisdom.

eharri3
11-17-2009, 09:10 PM
Bass tones are in fact not directional but for me it's in that transition from sub bass to midbass where I can start to detect where it's coming from, roughly in the 80-120 hertz range. If I transition from sub to front mids much above 80 HZ I can hear where my subs are. If I set it up at 70 HZ or below the sub is undetectable as the 'attack' portion of the deeper bass notes is solidly in front of me, providing the illusion that the whole bass note is coming from there. If you don't get mids that can do a decent job well below 100 HZ or don't get the crossovers set right, the lack of a smooth transition from sub bass to midbass can make your subs sound very directional. IF the sub is tuned to high it starts to become directional as it gets into the midbass range. If the sub is tuned just right but your front stage is lacking for midbass that frequency gap can make the sub's location very obvious to your ears.

I don't have experience running midbass drivers in the rear so I can't say what it's likely to sound like. Not a bad idea but probably not as good as incorporating them up front somehow. I can however say I do run rear coaxials and when I try to play them a little lower it hurts that up-front bass sensation I go for.

mlo
11-18-2009, 12:37 AM
I currently have a 10" sub in the Tahoe's rear barn door facing forward. When the HU volume is turned up and the sub is set where I like it is very directional and I believe the imaging is off. That is if what I percieve is infact imaging. I have been purposely relying on the sub so as to take the low load off the components for clearity with the HU's EQ.

What I am realizing though is that I much prefer the sound of backing the sub off and bringing the low notes higher than I think I should with the front components. I have played with the fader between the front and rear and actually think I could do without the rear altogether if the front was fuller sounding.

I am thinking of having a full length custom console made to house a sub in the front area. Not that it thrills me but because I think I have convinced myself it will sound the best. It is a family daily driver and maintaining a little storage and some decent cup holders would be nice hence being full length. Maybe even a double din area where it meets the oem dash for some options.

I also know that the components and power I currently have do not quite cut it when I try to rely on them alone. They seem to be lacking in fullness especially on normal moderate volume levels. I tend to use a volume setting of 9-14 mostly but find the speaker authority is best at 18-21. I would like to have the authority at the lower volume levels. I am assuming this will likely be a combination of all the componenets involved.

I would love to hear any feedback. TIA

Zellner
11-18-2009, 12:44 AM
This thread has the best written English I've ever seen on this site! I'm kind of excited about it! LOL

mlo
11-18-2009, 01:11 PM
After much reading and some generous consulatation I have committed to trying some different componenets. The speakers will be swapped for a set of BA Pro's and the HU will shortly be replaced with a P800PRS.

That HU will provide some expanded tuning options I currently do not have. My hope is that with some experimenting and higher quality speakers, I can tune-in what I percieve to be missing. I'm still reading on the possibility of having the system be made active as that option will also be more easily achieved. I recently tried and ditched a 700BT. I had an overall general distaste for it. I'm hoping the 800PRS will exhibit an entirely different feel...seems many believe it does.

The current installed sub will be removed from the rear. I am convinced for my listening taste and install requirements that any sub will need to be up front. Maybe I can find a great deal on a JL audio stealthbox for a short-term trial run before commiting to a custom console.

Always open for opinions and comments. TIA

headless
11-19-2009, 02:21 PM
Don't put midbass's behind you...then you have to pay for amplification of those channels, for those speakers, and you have to deaden those doors even more...and midbass's by definition will play directional sound that shouldn't come from behind you.

I really don't think you are going to need to mount a sub in your dashboard to be happy. How are your doors deadened currently? How much power is going to be available for your fronts if you get the BA's? Just a point of reference, when people sit in my car they tell me that the subs are totally nondirectional and actually ask more questions about my front speakers and why/how there is so much bass coming from up front than they ever do about the rear subs. Nowadays i'm using 80hz/18db slopes for my subs and fronts, so they aren't even really playing as low as they COULD - i used to run them at 63hz/24db until I got my subwoofer stage working out as I wanted. I use a little bit of time alignment to delay my fronts relative to my subs just slightly on my HU, but otherwise it's a pretty standard trunk setup.

This is because when you get things tuned correctly, all of the non-directional bass comes from the sub, and your front speakers can produce everything that is directional as loudly (or louder, with crossover) as your subs can. Consider that the power line CS's are 3.8 inches deep, though - they use the same baskets as the rainbow vanadium 7" subwoofers.

To get real clear response down to sub 70hz from your front doors you will need to deaden the crap out of them and start providing some beefy drivers (some BA drivers are pretty **** beefy, though i went with the rainbows :D) a lot of power; i'm pushing ~350watts per side, though in music i'm sure they only hit that kind of power, or close to it, very rarely and for extremely short transients. Trying to push this kind of power to drivers that can really move will cause the average door to vibrate too much, so extreme deadening is essential.

Get enough power on the right drivers up front in well prepared doors, with a decent deck for processing, and you will not need subs in your front dash to sound like the bass is coming from there.

I was very skeptical about this kind of thing when I first got into audio - all of my setups had frequency response holes at some frequencies, either due to my fronts being insufficient for the job, or the sub being in a bad enclosure, etc. - or phasing issues, etc.... what bothered me the most would be techno tracks where a midbass sweep would extend well down into the sub-bass area, and i'd feel like I was hearing something passing me by, going from the front of the car to the back as the frequency lowered. When things are balanced correctly, volume is consistent across the entire sweep and the sub only becomes louder than the fronts after it hits non-directional frequencies, so you can't hear it 'move' as it lowers in frequency.

The next thing that makes the biggest difference is vibrations from your car. Cars are big *** tin cans that are not really sound deadened. Walk outside and tap your door with your finger - the whole thing will vibrate and 'twang'. Now consider that this door is your speaker enclosure. Not such a nice proposition.

If your front doors vibrate like a ***** when they play 80hz, but when the sub is playing 40hz they don't vibrate at all, then you will always know that 80hz is coming from them and 40hz is coming from the sub due to the vibration sounds. I took off every plastic panel, applied sound deadener to the back, then glued on sound damping foam that, when clipped back into place, was 'snug' against the foam. I removed the door panels (plastic) and coated the backs of them with several layers of deadening, and did the inside and outside surfaces of the metal of the door itself, along with all metal in the bottom of the trunk and rear deck area and trunk lid...and sides of the trunk...then I removed the rear 6x9's so there would be airflow that would minimize rear deck vibration, and took the rear deck particleboard/carpeted piece and deadened it and coated it with sound damping foam so it was also a 'pressure fit'. A properly deadening vehicle doesn't have localizable vibrations that can point to where the source of the sound is.

mlo
11-19-2009, 06:55 PM
Only the doors themselves have been dynomatted (chrome looking). Although I do not believe the inside of the exterior door skin was done only the interior metal panel. I would be interested in hearing if the whole vehicle should be done for the full benefit.

My current amp is an Arc 300.4 which the specs say is a 4 channel (4x90w @ 4 ohm). I'm leaning toward buying another Arc amp likely the 300.2 2 channel (2x 180w @ 4 ohm) for use with the front BA Pro60 components. The 4 channel could then be used for the rear fill coaxials (?) and one bridged for use with a single 10" sub in the console...maybe a stealthbox. I am not 100% on this just leaning in that direction.

Your opinion matches what I have been told from another repectable member. Thanks for your time...I'm all ears!

headless
11-19-2009, 07:08 PM
If you don't deaden the exterior door skins, you will certainly be lacking in midbass response at some frequencies, due to the outer door skin vibrating out of phase with your speaker.

How did they deaden the interior door skin? Is it sealed off? How much did they install, in sq foot? What about the plastic door panels, anything done to those? The plastic door panels in my car were the worst offenders.

In my opinion, the minimum deadening you need is at least 15 sq foot per door. I used more. About 5sq foot on the outside door skin, another 5-7sqfoot on inside door skin, then in my case I put about 10sqfoot on the inside of the plastic door panel. Then I glued sound dampening foam to the inside of the plastic door panel to avoid vibrations of the panel against the door metal. You may find differing opinions on this tuff here - be careful about the (extremely prevalent here) bassheads telling you things that don't jive with your expectations of a coherent sound stage and (relatively) flat frequency response. Deadening your trunk area is important due to localized vibrations allowing you to tell where the sub freqs are coming from too; did they deaden your trunk? If so, how much deadening, and installed where? Too many shops are used to making cars designed around the subwoofer instead of the entire soundstage, and many of them seem to think that deadening the trunk roof and the metal door panels that the speakers are bolted to is 'all that's needed'. You don't need to do 'the whole vehicle'. I consider that taking out all the carpeting, roof liner, etc. etc. and literally coating the entire vehicle in deadener. It's overkill and you reach a point of massively diminishing returns very quickly. However, it is quick and easy to do the large plastic panels, at least, and the rear deck where the sub has the most impact, and those are what make the biggest difference.

You can judge, to an extent, if you need more deadening, though the human ear isn't the best device for this and many times you get more of an idea of 'it doesn't sound right' when dealing with frequency response 'holes' than a particular idea of, 'oh, why didn't I hear from 80 to 95 hz in that bass sweep?'. At least you can find if you have major vibration problems. Find a track with no vocals, and no high-hats or other midrange sound - a pure midbass/bass track. Play it at a reasonably high volume, then move around the cabin, listening for vibrations. You may find that with earplugs half in your ears you can hear the vibrations easier. Vibrations at high frequencies are what you want to avoid. A low frequency vibration will make your bass sound a little 'muddier', but won't signal your ear the same way a high frequency buzz would do. After I deadened all the plastic in my car, I was able to play the system louder before noticeable vibrations were introduced, thus the sound is 'cleaner' to the ear, especially at low volumes. I realised that a lot of the problems I was experiencing was due to additional sound being created through vibrations of the car's interior panels. Now, you're pushing a single 10" so you might not be getting THAT loud, but I am sure there will be an effect.

You'll want some content that varies in frequency - my panels vibrated really badly around 90hz, but not so badly at lower and higher frequencies. As I added deadening, they vibrated at different frequencies (and not at all at frequencies where they used to). If you can hear buzzing coming from your car that isn't being created by a speaker, then you need deadening. You can usually tell where it's needed simply by putting heavy pressure on the area that is buzzing.

Honestly, unless you are planning on going fully active, you can do fine with 2 amps. For example, that arc 300.4 could be bridged to push your front speakers (through passive x-overs) and then a monoblock could power your subs. That's how I did it at first - my 4150xxk is rated approximately the same as your arc 300.4. I bridged it to the power line CS and was pushing ~340watts per side. The only reason I added the 2100XXK was so that I could time-align my tweeters independently of the front woofers; I noticed that midrange sounds would 'walk' back and forth juuuuuuust slightly as the frequencies raised through the crossover frequency band - the tweeters would take over, and the difference in distance between the tweeters and me is more extreme than the difference in distance between me and the woofers. Independent time alignment per channel took care of that, but adding a third amp and tuning it is honestly a PITA. It took a year or so for the 'wandering' to bother me enough to motivate me to add the third amp. You're still fighting the subwoofer sounding like it's behind the car problem, so i don't think you'll be needing a full active setup quite yet ;) Tuning a fully active setup can be a real investment in time.

Dealing with 3 amps isn't worth the hassle unless you have processing for all channels and intend to run 6 independent channels (or at least 5 - 2xtweet, 2xwoofer, 1x sub), in my opinion. I would spend the money re: your rear coaxials on better front speakers and on higher rated amplifiers before i'd add coaxials to the car. You've really got to hear a set of front speakers that are designed to get loud to understand - rear speakers don't help unless you have a ****** frontstage, and if they do help, your frontstage must be really bad and the money would be better spent fixing the frontstage so you have a good sound and correct imaging rather than trying to band-aid it with more speakers in the back. Inevitably you realize that your imaging is ****ed and, due to speaker distance differences, time delay, reflections and phase issues, you STILL won't have dealt with the original problem - the front stage not being up to your expectations.

Wait; you said your 'amp' is a ks 300.4. Does that mean you're pushing 2 both fronts and rears with that amp now? I guess the D8400M is your sub amp then? Or are you using 2 channels from the arc for your sub now? Honestly, 180w is decent for the BA pro60's, but I have read of many people pushing double that to them and being happy with them, and read many posts where people swear that they need 300w to really get moving. My power line CS's were 'decent' at 150watts, but 'awesome' at 340watts+ available (right, filtor1? :D:D Aren't you pushing 400w/side to yours? lol). You need some headroom so that you're not maxing the amp out, even under the heaviest loads to get a good dynamic response without clipping.

eggyhustles
11-19-2009, 08:27 PM
anything is possible with the right tuning and the right drivers

go for it

mlo
11-19-2009, 11:31 PM
Not having any specifics about the actual deadening job, I went and visited the install shop. For a total of $300 they installed Dynomat only on the inside panel of the four doors. They figured 4-5 sq.ft. per front door and likely 2-3 sq.ft. for the smaller rear doors. Seems safe to say I need to revisit deadening the doors correctly. I assume there is a good possiblity the Dynomat already installed may need to be removed for access and replaced as well.

mlo
11-19-2009, 11:45 PM
Wait; you said your 'amp' is a ks 300.4. Does that mean you're pushing 2 both fronts and rears with that amp now? I guess the D8400M is your sub amp then?

Yes, the Arc 300.4 is currently powering the four doors which are Polk mm6051/651's. The Polks are being replaced with BA Pro 60's in the front doors. I was thinking of not running any rear fill initially and just bridging the Arc for 2 channels.

The current sub and the amp are also going away. I am contemplating a JL audio stealthbox console (looking for one used) and likely an Arc 300.2 bridged to power it.

headless...That was some time spent on your answer! I Thank you and enjoyed the read.

eggyhustles
11-20-2009, 02:01 AM
Not having any specifics about the actual deadening job, I went and visited the install shop. For a total of $300 they installed Dynomat only on the inside panel of the four doors. They figured 4-5 sq.ft. per front door and likely 2-3 sq.ft. for the smaller rear doors. Seems safe to say I need to revisit deadening the doors correctly. I assume there is a good possiblity the Dynomat already installed may need to be removed for access and replaced as well.

Jesus christ

HCCA
11-20-2009, 08:35 AM
Will your amp run down to 1 ohm? The Bostons Are 3 ohm drivers, so if you bridge the amp, it will be carrying 3 ohm mono load per pair of bridged channels.

I'm running 225 W/ch to mine, and I think that it is just barely loud enough. Though, I like it loud, I like it CLEAN. I'm contemplating a change to run my other amp to them to carry 350w/ch to them.

MLO, the 300.2 you were contemplating would be fine. At 3ohm load, it should be closer to 250+W/ch output. I think you could be happy with that.

Some really good info, from headless.

Too early in the morning to posting. I had to edit this post for accuracy.

headless
11-20-2009, 11:31 AM
Not having any specifics about the actual deadening job, I went and visited the install shop. For a total of $300 they installed Dynomat only on the inside panel of the four doors. They figured 4-5 sq.ft. per front door and likely 2-3 sq.ft. for the smaller rear doors. Seems safe to say I need to revisit deadening the doors correctly. I assume there is a good possiblity the Dynomat already installed may need to be removed for access and replaced as well.


****! I hate to say it, but that's some lazy *** ****. Putting deadening only on the inside of the inside door panels is just cutting corners. I would guess that they just didn't bother because they didn't want to clean the exterior door skins with acetone, and maneuvering the deadening through the holes in the inside door panel can be a little tricky.

At retail prices, a door kit, ~12sqfoot is ~40$. I used 2 of those plus a bulk pack plus about 60-80sq foot of RAAMat for my trunk and doors. I only put ~2sq foot in each of the rear doors because no speakers were mounted in them. For 300$ i would expect to be paying for the matierals and and installation of a bulk pack (~140$ at retail cost) correctly in my doors. That'd be ~18fq foot total per per door and should be good to go. I'd probably want an additional trunk kit installed too. With that much deadening, large portions of the plastic door panels and metal door skins would be covered with overlapping deadening or double layered. The trunk and 2 doors PROPERLY deadened shouldn't be a >500$ proposition, especially considering you could pick up an entire 62.5 sq. ft. roll of raamat for ~120$ and install it yourself in 4-5 hours.

headless
11-20-2009, 11:54 AM
Yes, the Arc 300.4 is currently powering the four doors which are Polk mm6051/651's. The Polks are being replaced with BA Pro 60's in the front doors. I was thinking of not running any rear fill initially and just bridging the Arc for 2 channels.

The current sub and the amp are also going away. I am contemplating a JL audio stealthbox console (looking for one used) and likely an Arc 300.2 bridged to power it.

headless...That was some time spent on your answer! I Thank you and enjoyed the read.


I would do exactly that - bridge the arc, deaden the living crap out of your front doors. Sell the rears to fund the beefiest front speakers you can afford. JL subs generally sound great. In your position I would probably go with 2 JL 10w6's sealed, though to be honest I prefer the rainbow vanadium 12's over the JL 12W6's, so really i'd probably try a pair of vanadium 10's sealed. Either one, though, i'd want to be pushing ~500w per sub, so if you stick with the 300.2, 1 sub is where it's at.

Where are you located, and who is doing your install?

mlo
11-20-2009, 12:30 PM
I would do exactly that - bridge the arc, deaden the living crap out of your front doors. Sell the rears to fund the beefiest front speakers you can afford. JL subs generally sound great. In your position I would probably go with 2 JL 10w6's sealed, though to be honest I prefer the rainbow vanadium 12's over the JL 12W6's, so really i'd probably try a pair of vanadium 10's sealed. Either one, though, i'd want to be pushing ~500w per sub, so if you stick with the 300.2, 1 sub is where it's at.

Where are you located, and who is doing your install?

Paying someone to perform services is always a risk. What goes on behind your back and in this case behind the door panels is an enticing place to take the easy way out for those looking for one. Especially when I did not spec the job to every detail. The shop I chose knows better, I am convinced. Thier own stuff is impeccable.

I did not go looking for a sub particularly. After being quite dissapointed with the outcome of the installs performance the installer kept pushing me there to create in his eyes "the fullness" I desired. My biggest criteria for any sub was that the integration be stealthy and look oem. I think I am convinced that if a sub is truly needed the console variety would suit my design taste.

The installing shop was CSL auto electronics Inc. I'm near Seattle Wa.

I was thinking of using a 300.2 for the BA componenets. And the already owned 300.4 for the rear coaxials and sub. Though really the plan is evolving here.

Thanks to everyone for your time.

Beerdrnkr
11-20-2009, 04:54 PM
I didn't read everything but there's a good thread on Diyma about having extra midbass behind you and it can workout if you do things properly. I'm currently using a 9887, 4 2" fullrange drivers in the a-pillars, 8's in the doors, and 3 12's ported that will be changing to 1 12" sealed. I'm changing everything up and will be trying out a pointsource set of comps in my kickpanels w/ passive xovers (300wrms to each set), I'm keeping the dayton 8's in the doors (300wrms to each), and shortly I will also install dayton 7's in the rear doors with about 150wrms to each. Apparently you want to give the front midbass a lot more power so you're not bringing the midbass to the back. I'm not sure how much more processing you'd need to really keep the midbass up front but I'm planning on looping the rca's from one midbass amp to the other and using the t/a to get it as up front as possible although it will be affecting each set of midbass differently. I have my front doors deadened pretty solid and my rear doors will also be very deadened because I think it's already been posted but rattles and vibrations will cause more localizations of the midbass frequencies.

hanzuozuo1984
11-21-2009, 02:36 AM
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HCCA
11-21-2009, 10:31 AM
****! I hate to say it, but that's some lazy *** ****. Putting deadening only on the inside of the inside door panels is just cutting corners. I would guess that they just didn't bother because they didn't want to clean the exterior door skins with acetone, and maneuvering the deadening through the holes in the inside door panel can be a little tricky.

At retail prices, a door kit, ~12sqfoot is ~40$. I used 2 of those plus a bulk pack plus about 60-80sq foot of RAAMat for my trunk and doors. I only put ~2sq foot in each of the rear doors because no speakers were mounted in them. For 300$ i would expect to be paying for the matierals and and installation of a bulk pack (~140$ at retail cost) correctly in my doors. That'd be ~18fq foot total per per door and should be good to go. I'd probably want an additional trunk kit installed too. With that much deadening, large portions of the plastic door panels and metal door skins would be covered with overlapping deadening or double layered. The trunk and 2 doors PROPERLY deadened shouldn't be a >500$ proposition, especially considering you could pick up an entire 62.5 sq. ft. roll of raamat for ~120$ and install it yourself in 4-5 hours.

I used Second Skin Damplifier Pro, and I think it cost me $700 to do the ENTIRE vehicle (minus the roof), two layers in all four doors. Three layers on the wheel wells. PLUS Luxury Liner Pro, on the entire floor. Plus Overkill Pro in the doors. That cost was also including 6 cans of adhesive spray. That was my cost to install it myself.

mlo
11-21-2009, 01:14 PM
Thanks for the specifics HCCA...That is where I am at right now. Trying to educate myself on quality deadening products and there correct application/location.

After doing some searching I am thinking I may want do an amp upgrade at the same time the BA Pro's go in. I really like the simplicity of having one capeable amp to supply the front components and the very likely addition of a stealthbox sub. The Pioneer sub and amp I was using is gone and I am sure If I wanted to, I could find a home for the Arc300.4. Thoughts...

If anyone knows of a great deal on a gray JL stealthbox console please pm me.