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toymachine2628
03-10-2008, 10:44 PM
what frequency response is mid bass?

what is mid range?

It seems to me that a good comp. set (6.5") should have many aspects. detail, clarity, tonal balance, definition, and an overall brilliance to them..

why is it that most members recommending speakers say " great midbass" first.

to me it is an important aspect of a speaker, but it definitely not the most important.

should we leave the low frequency response for larger diameter speakers in boxes?

any explanations and opinions welcome!!!

Random1010
03-10-2008, 10:49 PM
its th frequency range above the sub but not in the mid range

tcguy85
03-10-2008, 10:57 PM
i think mid-bass is something that stands out because it's harder to get great mid-bass output.

tRidiot
03-10-2008, 11:03 PM
i think mid-bass is something that stands out because it's harder to get great mid-bass output.

Absolutely

It's an extremely important aspect for me, due to my choice of music and listening style.

I consider midbass to be in the 60-120Hz range, really.

tcguy85
03-10-2008, 11:07 PM
mid-range quality and output should be just as important, same with highs of course. but mid-bass just seems harder to achieve. sub-bass, mid-range, and highs come easy.

toymachine2628
03-11-2008, 12:20 AM
i know listening to music is subjective. ok, i try my explanation. i would consider the perfect speaker to be perfectly balanced, but have clarity and detail of the speaker let the different freq. be defined.

I have notice the new rockford fosgate power amps have a distinct feature. That is the freq. response is skewed at the mid- bass and high freq. ranges. Is this a growing trend in amps? Is all we looking for is enhanced mid bass?






*FYI* i would never buy an amp without a flat freq. response*

tcguy85
03-11-2008, 12:34 AM
i know listening to music is subjective. ok, i try my explanation. i would consider the perfect speaker to be perfectly balanced, but have clarity and detail of the speaker let the different freq. be defined.

I have notice the new rockford fosgate power amps have a distinct feature. That is the freq. response is skewed at the mid- bass and high freq. ranges. Is this a growing trend in amps? Is all we looking for is enhanced mid bass?






*FYI* i would never buy an amp without a flat freq. response*

huh? where did you get this data?

toymachine2628
03-11-2008, 12:40 AM
http://www.rockfordfosgate.com/news/templates/template.asp?articleid=255&zoneid=3

Its a review of the t600-2 from caraudio and electronics.

tcguy85
03-11-2008, 01:03 AM
http://www.rockfordfosgate.com/news/templates/template.asp?articleid=255&zoneid=3

Its a review of the t600-2 from caraudio and electronics.

hmmmm interesting. not a fan of that idea at all.

BrianChia
03-11-2008, 04:07 AM
I agree with the OP--we should not be looking for particular bands of output, but for a system that can blend all frequencies together smoothly for a flat and realistic response.

Midbass is just a hot buzzword for component sets right now.

helotaxi
03-11-2008, 05:00 AM
It's more than a buzzword. The front speakers should go as low as possible for the best staging and imaging. Upfront bass has pretty much always been the goal, it's just that more people are starting to care about how it sounds not just how far away it can be heard so you hear more about it now. The subs shouldn't be playing the midbass freqs.

xplicitACTS
03-11-2008, 05:19 AM
This little guys, especially in a 2 way front stage has in my opinion the toughest job. In all honesty without a good mid bass the subwoofer just does not sound complete....80-3khz is a tough area to cover and still keep its composure.

toymachine2628
03-11-2008, 07:44 PM
It's more than a buzzword. The front speakers should go as low as possible for the best staging and imaging. Upfront bass has pretty much always been the goal, it's just that more people are starting to care about how it sounds not just how far away it can be heard so you hear more about it now. The subs shouldn't be playing the midbass freqs.

an intelligible explanation is needed... you need to elaborate. This is a discussion these kind responses do nothing but confuse and mislead people.

i dont understand why if your front speakers have lower freq. response you have the best staging and imaging, explain..

i dont understand why it is the goal. almost every speaker review and recommendation on caraudio forums include GreaT MidBass. shouldnt the goal be to have perfect balance of all freq.?

why shouldnt sub play midbass freq, explain.

Trey803
03-11-2008, 07:46 PM
if you listen to music with bass guitar you will respect the midbass more

toymachine2628
03-11-2008, 08:09 PM
if you listen to music with bass guitar you will respect the midbass more

i have respect for all freq, i just dont choose one when listening to my music.

miker
03-11-2008, 08:23 PM
i have respect for all freq, i just dont choose one when listening to my music.


YEah, but you don't want to be lacking in one either

toymachine2628
03-11-2008, 09:30 PM
YEah, but you don't want to be lacking in one either

really, explain? since your so smart

hoss
03-11-2008, 09:44 PM
as helotaxi said, you want to have as much "upfront" bass as possible to keep imaging and blending properties in your set up.

one thing i will go out and say in rebuttal to his statement (actually, not so much a rebuttal but perhaps an addendum :) ), lower frequencies start to become omni directional below a certain frequency, meaning that you cannot pinpoint the source of the sound. this is why subs are fine to be located behind the listener, while other speakers need to be in front of or as closely aligned to the listener as possible (higher frequencies are even more directional. imagine the higher frequencies acting like a beam while lower freqs start to fan out more and more until they eventually fan out all the way in 360 degrees). why am i telling you this? so you can understand why you need to find the cut off point between sub-bass and mid-bass ;)

another factor as to why people make a big deal about mid-bass is, like people have said, it is often difficult to get a good mid-bass reproduction in your stereo install. as the frequencies get lower and lower, the cone speed slows down, thusly, the effective range that the speaker reproducing the sounds gets smaller since the cone cant move fast and slow at the same time. so to get a great reproduction throughout the entire human listening range, you would need more and more speakers, which is hardly ever practical or effective...

i just got distracted and i guess thats really all i got for right now... maybe someone will follow behind me and reinforce or correct something i said :)

toymachine2628
03-11-2008, 09:58 PM
as helotaxi said, you want to have as much "upfront" bass as possible to keep imaging and blending properties in your set up.

one thing i will go out and say in rebuttal to his statement (actually, not so much a rebuttal but perhaps an addendum :) ), lower frequencies start to become omni directional below a certain frequency, meaning that you cannot pinpoint the source of the sound. this is why subs are fine to be located behind the listener, while other speakers need to be in front of or as closely aligned to the listener as possible (higher frequencies are even more directional. imagine the higher frequencies acting like a beam while lower freqs start to fan out more and more until they eventually fan out all the way in 360 degrees). why am i telling you this? so you can understand why you need to find the cut off point between sub-bass and mid-bass ;)

another factor as to why people make a big deal about mid-bass is, like people have said, it is often difficult to get a good mid-bass reproduction in your stereo install. as the frequencies get lower and lower, the cone speed slows down, thusly, the effective range that the speaker reproducing the sounds gets smaller since the cone cant move fast and slow at the same time. so to get a great reproduction throughout the entire human listening range, you would need more and more speakers, which is hardly ever practical or effective...

i just got distracted and i guess thats really all i got for right now... maybe someone will follow behind me and reinforce or correct something i said :)


thank you.

helotaxi
03-12-2008, 12:24 AM
Actually a speaker can and does move both fast and slow at the same time. The best speakers do it quite well and they are the ones that give good midbass response. There is no hard and fast rule as to the exact frequency cutoff where sound is easily placeable as to its source. As such you try to get the front speakers going as low as possible to remove any chance of a random bass note suddenly placing itself as coming from the sub behind you.

Yes, the full spectrum of frequencies should be balanced and that is why getting good midbass is important. The resonance nodes of the typical car along with the typical speaker placement causes a cancellation node right in the middle of the midbass range and most car installs horribly lack midbass. This leads many to turn up the low pass freq on the subs which then drags the midbass range to being localized as coming from the subs. Totally wrecks the soundstage when it sounds like the band is in front of you except for the bass player and the drum kit is spread all over the place.

As driver diameter increases it also tends to cause an effect called beaming. The freq at which a driver beams is inversly proportional to its diameter. So a large diameter driver beams at a lower freq than a smaller one. A driver that is playing above its beam freq displays a very focused dispersion pattern and the response off axis gets pretty ragged. This is one of the reasons that tweets are small. The other problem associated with driver size is breakup. As a large diaphram tries to reproduce a high freq, the cone begins to flex and ad harmonic content that colors the sound. Smaller drivers can be made stiffer than larger ones for a given mass. High stiffness to mass ratios become important because of voicecoil inductance. To move a heavy cone you need a large voicecoil. A large voicecoil will have a higher inductance which will limit the upper range of the driver's response. High freq drivers need to have a very low inductance and thus need a small coil.

The end result of all of this is that the ideal setup would be a driver able to play from below 20Hz to above 20kHz by itself. This isn't possible so the next best thing is to have a single driver cover as much of the audible spectrum as possible. To this end most DIY guys try to find a tweeter that will play as low as possible allowing them to pair them with a larger midrange. The larger cone area of the midrange allows it to play down low with some authority and limiting it on the top end keeps it from beaming and/or breaking up at higher freqs. The other way that this is handled is to run a 3-way front stage where the midrange plays well up into the freq normally handled by the tweeter in a 2-way setup leaving a dedicated midbass driver and the tweet to fill in the rest. Either method can yield excellent results depending on the specific goals of the system.

Notice I didnt' even mention the subs. If the front stage is done right, the subs are almost an afterthought. They will only cover the bottom octave and a half at most.

XxSuperAdamxX
03-12-2008, 12:30 AM
I never paid attention to midbass like a year ago, but about half a year ago I started to care about mid bass. It has a nice punch to songs, playing certain frequency that subs can't play.

WhoSayWho?
03-12-2008, 12:31 AM
an intelligible explanation is needed... you need to elaborate. This is a discussion these kind responses do nothing but confuse and mislead people.

i dont understand why if your front speakers have lower freq. response you have the best staging and imaging, explain..

i dont understand why it is the goal. almost every speaker review and recommendation on caraudio forums include GreaT MidBass. shouldnt the goal be to have perfect balance of all freq.?

why shouldnt sub play midbass freq, explain.

You are an idiot.

XxSuperAdamxX
03-12-2008, 12:49 AM
You are an idiot.

Haha, come on now. Let the guy ask the questions. With more post on this thread he can understand more.

WhoSayWho?
03-12-2008, 01:14 AM
Haha, come on now. Let the guy ask the questions. With more post on this thread he can understand more.

As far as I am concerned he can ask all of the questions that he wants, stupid or otherwise. You will not catch me flaming someone for simply not knowing the answer to his own question.

However, when someone has this type of reply to someone who is trying to help him, it irks me:


an intelligible explanation is needed... you need to elaborate. This is a discussion these kind responses do nothing but confuse and mislead people.
i dont understand why if your front speakers have lower freq. response you have the best staging and imaging, explain..

i dont understand why it is the goal. almost every speaker review and recommendation on caraudio forums include GreaT MidBass. shouldnt the goal be to have perfect balance of all freq.?

why shouldnt sub play midbass freq, explain.

Do0d acts like he is paying for the advice.

skydeaner
03-12-2008, 01:29 AM
sounds like toymachine has a little midbass envy going on... maybe his woofer is a lil too small, or doesn't move like most peoples.

hehe, just kiddin, there have been some very good points made in this thread. Midbass is so hard to achieve in the car for many reasons. One is the enclosure problem. If we could drop a two cubic foot enclosure in the leg area of each front seat it would be no problem getting adequate midbass out of a 6.5 or 5.25 driver in the car. But for most people, the partially sealed heavily dampened inside of a door panel will have to do. Cabin gain helps out some, but has less of an impact the higher frequency you go. Not to mention that makes the drivers almost playing in free air, so their excursion goes kinda wild under the drivers resonant frequency.

The fact that it is hard to come by is why it is always mentioned in reviews. You can't just ignore the 65-120hz frequency range or 80-120 whatever you want to consider your midbass area. And with the subwoofers playing in that band it is pretty easy to localize them as coming from behind you, not to mention a lot of subwoofers frequency response in this area is less than desireable, or they just sound like crap playing at 120hz at the same time they are trying to belt out a 35hz thud. It is almost impossible to find a 10"-15" that will play 25-30hz at an acceptable level and still be able to play up to 120 and sound good, let alone play as loud as most people play their car stereos.

WrenchGuy
03-12-2008, 01:35 AM
Midbass is as important as the cow bell!

MyFartsStink
03-12-2008, 01:45 AM
I find that I get alot better mid-bass responce when I put speakers in sealed enclosures.

oldschool4me
03-12-2008, 02:00 AM
yes, i agree a midbass is important in a good sounding system. a midbass woofer and a midrange woofer are not the same thing. a common misunderstanding. an actual midbass usually designed to be in the 25- 500 hz range. a mid woofer is designed to go much higher and usually lack in the say 80-250hz range. i like to use midbass speakers in the rear deck. i also am firm on using baffles to help with acoustics. i listen to a variety of music and for some music it is a great enhancement to have a great ( lets not say midbass lol) we will use low to mid frequency range, such as drums, bass guitar, vocals etc. if you like to feel your music and not just the bass then this is something you may want to look into. if you enjoy schrill highs then dont worry about it, your all set.

oldschool4me
03-12-2008, 02:35 AM
http://www.woofersetc.com/index.cfm?fuseaction=product.display&Product_ID=2592

notice the frequency range. your front stage will pick up anything higher.

helotaxi
03-12-2008, 06:49 AM
Problem with running something like that in the rear deck is that they are easily localized. So much for any semblance of proper staging.

There are drivers out there that will flat own those Kickers in the midbass region and still play high enough to pair with a low Fs tweet.

toymachine2628
03-12-2008, 10:52 AM
Actually a speaker can and does move both fast and slow at the same time. The best speakers do it quite well and they are the ones that give good midbass response. There is no hard and fast rule as to the exact frequency cutoff where sound is easily placeable as to its source. As such you try to get the front speakers going as low as possible to remove any chance of a random bass note suddenly placing itself as coming from the sub behind you.

Yes, the full spectrum of frequencies should be balanced and that is why getting good midbass is important. The resonance nodes of the typical car along with the typical speaker placement causes a cancellation node right in the middle of the midbass range and most car installs horribly lack midbass. This leads many to turn up the low pass freq on the subs which then drags the midbass range to being localized as coming from the subs. Totally wrecks the soundstage when it sounds like the band is in front of you except for the bass player and the drum kit is spread all over the place.

As driver diameter increases it also tends to cause an effect called beaming. The freq at which a driver beams is inversly proportional to its diameter. So a large diameter driver beams at a lower freq than a smaller one. A driver that is playing above its beam freq displays a very focused dispersion pattern and the response off axis gets pretty ragged. This is one of the reasons that tweets are small. The other problem associated with driver size is breakup. As a large diaphram tries to reproduce a high freq, the cone begins to flex and ad harmonic content that colors the sound. Smaller drivers can be made stiffer than larger ones for a given mass. High stiffness to mass ratios become important because of voicecoil inductance. To move a heavy cone you need a large voicecoil. A large voicecoil will have a higher inductance which will limit the upper range of the driver's response. High freq drivers need to have a very low inductance and thus need a small coil.

The end result of all of this is that the ideal setup would be a driver able to play from below 20Hz to above 20kHz by itself. This isn't possible so the next best thing is to have a single driver cover as much of the audible spectrum as possible. To this end most DIY guys try to find a tweeter that will play as low as possible allowing them to pair them with a larger midrange. The larger cone area of the midrange allows it to play down low with some authority and limiting it on the top end keeps it from beaming and/or breaking up at higher freqs. The other way that this is handled is to run a 3-way front stage where the midrange plays well up into the freq normally handled by the tweeter in a 2-way setup leaving a dedicated midbass driver and the tweet to fill in the rest. Either method can yield excellent results depending on the specific goals of the system.

Notice I didnt' even mention the subs. If the front stage is done right, the subs are almost an afterthought. They will only cover the bottom octave and a half at most.

Thank you so much! I am starting to understand.

toymachine2628
03-12-2008, 11:26 AM
You are an idiot.

I just wanted to understand, I wanted an more advanced explanation that's all. why would you call me or anyone an idiot? Even on the internet words have meaning and can hurt.

lillitnn92
03-12-2008, 01:16 PM
*FYI* i would never buy an amp without a flat freq. response*

wow, i just don't understand this at all. being a recreational home studio musician myself also, this statement floors me. in order to achieve that perfect sound, you should want flat response from your HU to your amps and your speaker set up. you should be hearing the music as it was intended to be heard from the producer of that song/album. you should never have certain parts of the frequency exaggerated....this is of course unless you're a bass head. in the professional audio world flat is what you want to hear. when everything is perfect from 20hz to 20khz you'll get better spatial imaging and you will hear things in songs you've never heard before. bass, mid, treble and bass boost settings are there so you can compensate for the loss/gain in these areas so your overall experience listening is better, not to make the song something it's not.

oldschool4me
03-12-2008, 01:25 PM
Problem with running something like that in the rear deck is that they are easily localized. So much for any semblance of proper staging.

There are drivers out there that will flat own those Kickers in the midbass region and still play high enough to pair with a low Fs tweet.

i used those as a refference. i didnt say they were the best thing out lol. it is just a better sound if you use a speaker that does not lack in lower mid frequencies which is usually what you get when you get a comp set. of course your high end sets will have good drivers but most people dont have $500+ to sink into a set. so a decent midbass driver is an improvement on your common midrange driver. if you have a low end comp set in your rear deck replace the driver with a decent midbass and then tell me im wrong. for $200 you can get these.
http://www.woofersetc.com/index.cfm?fuseaction=product.display&Product_ID=4850

solidcrowd
03-12-2008, 02:27 PM
I had pg rsd6.5 comps and I didn't have much midbass. Was it the comps or the fact that the doors weren't sealed or deadened, because the lowest freq they get to is 45hz? Whats more important.

I know for substage it's mostly like enclosure but what about frontstage midbass since there is no enclosure.

WhoSayWho?
03-12-2008, 02:33 PM
I just wanted to understand, I wanted an more advanced explanation that's all. why would you call me or anyone an idiot? Even on the internet words have meaning and can hurt.


I thought my subsequent post explained why I said that:



As far as I am concerned he can ask all of the questions that he wants, stupid or otherwise. You will not catch me flaming someone for simply not knowing the answer to his own question.

However, when someone has this type of reply to someone who is trying to help him, it irks me:



Do0d acts like he is paying for the advice.

You see, it had nothing to do with what you were trying to learn. It had everything to do with you sounding ungrateful and like a bit of a jackass. Perhaps you just do not express yourself well in writing.

Rather than posting what you did, you could have said something like, "Thanks for the reply, but I am not quite sure I understand. Can you please explain...."

jmanpc
03-12-2008, 02:40 PM
I know it's probably already been said, but midbass is what bridges the gap between sub-bass and midrange. Strong midbass is essential in blending the sub with the front speakers. Weak midbass makes it seem like there's a separation between the mids and lows; they just don't mesh correctly. Strong midbass is especially important when the music contains bass guitar, synthesizers, etc.

Flipx99
03-12-2008, 02:40 PM
I run 8" midbass...so wha?

miker
03-12-2008, 04:01 PM
I had pg rsd6.5 comps and I didn't have much midbass. Was it the comps or the fact that the doors weren't sealed or deadened, because the lowest freq they get to is 45hz? Whats more important.

I know for substage it's mostly like enclosure but what about frontstage midbass since there is no enclosure.

It's the install. . . I have the same issue.:crap:

oldschool4me
03-12-2008, 04:09 PM
I had pg rsd6.5 comps and I didn't have much midbass. Was it the comps or the fact that the doors weren't sealed or deadened, because the lowest freq they get to is 45hz? Whats more important.

I know for substage it's mostly like enclosure but what about frontstage midbass since there is no enclosure.

you can try adding baffles they help some and are a cheap improvement. but like i was saying most mids that come with your comp sets lack midbass unless you payng high$ for them. if your still not happy, look into different woofers like the cdt's i linked or similar. what do you have in your rear fill?

miker
03-12-2008, 04:10 PM
you can try adding baffles they help some and are a cheap improvement. but like i was saying most mids that come with your comp sets lack midbass unless you payng high$ for them. if your still not happy, look into different woofers like the cdt's i linked or similar. what do you have in your rear fill?

Yeah, but that was one of the reasons PG's were a boner... good mid-bass.

krisfnbz
03-12-2008, 07:49 PM
I hate mid-bass. Its too expensive to achieve ****it!

James Bang
03-12-2008, 08:00 PM
you can try adding baffles they help some and are a cheap improvement. but like i was saying most mids that come with your comp sets lack midbass unless you payng high$ for them. if your still not happy, look into different woofers like the cdt's i linked or similar. what do you have in your rear fill?
too hell with rear fill.
I'd rather have my midbass up front, along with my highs and lows.

helotaxi
03-12-2008, 08:26 PM
wow, i just don't understand this at all. being a recreational home studio musician myself also, this statement floors me. in order to achieve that perfect sound, you should want flat response from your HU to your amps and your speaker set up. you should be hearing the music as it was intended to be heard from the producer of that song/album. you should never have certain parts of the frequency exaggerated....this is of course unless you're a bass head. in the professional audio world flat is what you want to hear. when everything is perfect from 20hz to 20khz you'll get better spatial imaging and you will hear things in songs you've never heard before. bass, mid, treble and bass boost settings are there so you can compensate for the loss/gain in these areas so your overall experience listening is better, not to make the song something it's not.

It appears that you misread the post that you quoted specifically the "without" in there.

helotaxi
03-12-2008, 08:29 PM
i used those as a refference. i didnt say they were the best thing out lol. it is just a better sound if you use a speaker that does not lack in lower mid frequencies which is usually what you get when you get a comp set. of course your high end sets will have good drivers but most people dont have $500+ to sink into a set. so a decent midbass driver is an improvement on your common midrange driver. if you have a low end comp set in your rear deck replace the driver with a decent midbass and then tell me im wrong. for $200 you can get these.
http://www.woofersetc.com/index.cfm?fuseaction=product.display&Product_ID=4850

Again, you missed the point. Having the midbass (any midbass, not just those Kickers) in the rear deck will trash the sound stage. If something like that is what you're looking for on a budget, you'd be better served by putting a set of 4" coaxes in the kicks and use the door locations for a dedicated midbass driver.

hoss
03-12-2008, 08:33 PM
Again, you missed the point. Having the midbass (any midbass, not just those Kickers) in the rear deck will trash the sound stage. If something like that is what you're looking for on a budget, you'd be better served by putting a set of 4" coaxes in the kicks and use the door locations for a dedicated midbass driver.

:word:

i put my mid-basses behind me because i was too lazy to fabricate door pods for them, it sounds like poo :(

lillitnn92
03-12-2008, 09:13 PM
It appears that you misread the post that you quoted specifically the "without" in there.

so i did, you may kill me now....no please! i read fast right before work. i apologize sincerely to all. i'm walking away now.

oldschool4me
03-12-2008, 10:55 PM
too hell with rear fill.
I'd rather have my midbass up front, along with my highs and lows.

been into audio for about 17 years and will never understand this. its like having a home theater system with 2 speakers. to me front and rear is just as important as left and right. might as well be mono imo. maybe its just a few of us that think this way idk.

hoss
03-12-2008, 10:59 PM
been into audio for about 17 years and will never understand this. its like having a home theater system with 2 speakers. to me front and rear is just as important as left and right. might as well be mono imo. maybe its just a few of us that think this way idk.

do you drive your home theater down the highway at 70 mph? also, do you have at least 6' between your front and rear speakers?

if the answer to either of these is "no", you have succesfully spotted the difference between your home theater and your car stereo, and hopefully gotten some insight as to why most everyone thinks rear fill is a bad idea in a car stereo application :)

gladiator_jai
03-12-2008, 11:05 PM
Hmm, I have my midbass behind me, and after reading through this thread now I know why I am not completely satisfied with my sound. Thanks Guys :D

oldschool4me
03-12-2008, 11:20 PM
Again, you missed the point. Having the midbass (any midbass, not just those Kickers) in the rear deck will trash the sound stage. If something like that is what you're looking for on a budget, you'd be better served by putting a set of 4" coaxes in the kicks and use the door locations for a dedicated midbass driver.

well i ususally put a 4 inch mid in the rear as well as midbass. correct me if im wrong but in my experience i found that the frequencies that i was trying to improve were for the most part at a range that was non directional. not saying that front stage is not important because it is. good front stage is one of the most important.

as for coax speakers. nope. comp sets or plates for me. and as for kick panels. no! if there is nowhere to have speaker in the front then i would. the doors and or dash seem to work great for me. kicks are tacky. they usually get kicked too, hence the name lol. i would cut another hole in my door first, if i needed more front stage.

oldschool4me
03-12-2008, 11:46 PM
do you drive your home theater down the highway at 70 mph? also, do you have at least 6' between your front and rear speakers?

if the answer to either of these is "no", you have succesfully spotted the difference between your home theater and your car stereo, and hopefully gotten some insight as to why most everyone thinks rear fill is a bad idea in a car stereo application :)

no to the first question and yes to the second. but im confused on the questions. wondering what they have to do with front/rear seperation?

newusername
03-13-2008, 12:53 AM
Bored.....

So on topic:

Re: Localization of subwoofer
- Given the appropriate lowpass filter, a subwoofer's direct sound is not easy to locate. It's the reflected sound that is a concern: it typically excites resonance in various parts of the vehicle that have considerable storage problems. From this, it can be quite easy to localize a subwoofer. Thus, it is good to cross your mids as low as possible (or bring a subwoofer up front).

Re: Left/Right vs Front/Back
- If there were front/back information available in a stereo recording, I would agree that it was as important. However, there simply isn't. There are circumstances in which it can be important, but never as important as L/R.

Re: Why midbass?
- Typical 6.5" midrange drivers are virtually devoid of quality midbass output. A lot of drivers out there should not even be used below 100 Hz (particularly in those pre-made component sets that so many people use). So in the rare event that someone has designed a quality driver with good midbass, it is worth noting. Let's not forget that there is a lot of fundamental and second or third order harmonic information below 200 Hz.

Re: The use of rear fill
- This is a long one. First, space up front is limited. Is it the easiest location to put an 8" or larger midbass? Definitely not. So how do we achieve that visceral output from the midbass that is so enjoyable? The only option left is to find a spot in the rear (typically rear deck in sedans).

Concerns about localization are valid. But it is a complex issue. In terms of stage width (ie. localization along the horizontal axis), there are two key concerns. They are ITD (differences in arrival times) and IID (differences in SPL). It should be noted that ITD is a dominant effect below 1-2 kHz and IID is a dominant effect above that. There is some overlap, of course.

But there is something very important in this particular argument: it's called the Haas Effect, named after the German Helmut Haas. Basically, it says that if the difference in arrival times between two sources with the same material is less than 25-35 ms, then the perception of the latter of the two sources is suppressed. Here is where Time Alignment comes in really handy: if you can't account for this physically, you can electronically delay the front speakers to make sure the difference between front and rear is less than the Haas Effect....and thus, the rear speakers should be hard to locate.

Of course, the concept is just cut and dry. Since we localize using ITD at low frequencies, everything is fine (for the most part) in the midrange and midbass frequencies. However, at high frequencies, we use IID to localize. The addition of a second source creates a comb filtering effect, ie. dips and nulls are created in SPL. This isn't a big deal for low frequencies, but it directly affects our localization along the horizontal axis at upper frequencies.

So in short, we should draw the conclusion that the addition of a second source in the rear is not a big deal at low frequencies if we manage the Haas Effect appropriately. However, it can be detrimental in localization in the treble. And although it doesn't affect the localization at low frequencies, the creation of peaks and nulls in SPL at low frequencies is still a problem if an even, accurate response is the goal. Of course, the use of an EQ goes a long way here...at least localization isn't a problem.

Re: Is midbass in the rear practically realizable?
- It is important that conclusions we draw in theory are realizable in practice, otherwise the theory is inaccurate. And if you look around, there are a number of installs that either use multiple midbass or midbass in the rear (or both) with great success. Off the top of my head, there are some guys you might have heard of known as SpeakerWorks who have had great success using midbass in the rear.

It isn't a tactic that is used often because it is still widely misunderstood, but offers great potential. Imagine, for a moment, that you have a small 6.5" driver up front. You play it down to the crossover point but obviously lack the output you're looking for. Good news! You may keep it in the current bandwidth, add large midbass drivers in the rear, keep the difference in front/rear arrival times below 30 ms, lowpass below the frequencies at which IID becomes prominent, EQ out any unevenness, and gain output with no effects on localization. Much like the use of a subwoofer in the rear, it is important to minimize resonance of surrounding panels. It's complicated but the result is worthwhile.

dwc
03-13-2008, 01:12 AM
been into audio for about 17 years and will never understand this. its like having a home theater system with 2 speakers. to me front and rear is just as important as left and right. might as well be mono imo. maybe its just a few of us that think this way idk.

I have to take issue (call BS) on this. First off we are talking about two-channel systems, not 5.1 surround systems. And even if we *were* talking 5.1 surround, would you take the midrange drivers out of your center and front L/R channels and mount them in boxes behind you? Of course not. That's what is being discussed here...

vipervin
03-13-2008, 01:58 AM
Great thread here. I finally learned why my front stage *****... I need m0re midbass!

Thanks guys.. time to spend my next paycheck on re-doing my front stage.

BrianChia
03-13-2008, 02:18 AM
If you have experienced real stereo imaging you will understand how significant it can be. Adding rear channels WILL localize sounds since we cannot perceive front to rear imaging. Imaging is a psychoacoustic effect made possible because we have two ears that process sounds independently but combine the inputs to create the image. The "phantom center" effect cannot be duplicated as a "phantom side" channel by front and rear speakers. It would just sound like a speaker in the front and one in the back.

oldschool4me
03-13-2008, 02:29 AM
I have to take issue (call BS) on this. First off we are talking about two-channel systems, not 5.1 surround systems. And even if we *were* talking 5.1 surround, would you take the midrange drivers out of your center and front L/R channels and mount them in boxes behind you? Of course not. That's what is being discussed here...

i was not saying we arent, just saying it makes as much sence to me. rear fill to me is just as improtant. not as important to other people but you will have that. some like it some dont. havent seen many sq comp systems with no rear fill. but i think we are somewhere around here, quoted from above....


It is important that conclusions we draw in theory are realizable in practice, otherwise the theory is inaccurate. And if you look around, there are a number of installs that either use multiple midbass or midbass in the rear (or both) with great success. Off the top of my head, there are some guys you might have heard of known as SpeakerWorks who have had great success using midbass in the rear.

It isn't a tactic that is used often because it is still widely misunderstood, but offers great potential. Imagine, for a moment, that you have a small 6.5" driver up front. You play it down to the crossover point but obviously lack the output you're looking for. Good news! You may keep it in the current bandwidth, add large midbass drivers in the rear, keep the difference in front/rear arrival times below 30 ms, lowpass below the frequencies at which IID becomes prominent, EQ out any unevenness, and gain output with no effects on localization. Much like the use of a subwoofer in the rear, it is important to minimize resonance of surrounding panels. It's complicated but the result is worthwhile.

BrianChia
03-13-2008, 02:49 AM
Outside of a true line source array, multiple sources of the same frequency will destroy stereo imaging. It's that simple. Doesn't matter how much you delay or attentuate the channels.

newusername
03-13-2008, 02:52 AM
Outside of a true line source array, multiple sources of the same frequency will destroy stereo imaging. It's that simple. Doesn't matter how much you delay or attentuate the channels.

That is your opinion and differs with many. Aside from the vehicles (and homes and professional applications) where it has been used successfully.

If you follow the steps outlined, I think you will feel differently. Have you tried this? Have you listened to anything using a similar setup? Do you have information that directly disproves what I have outlined above?

Pretty sure there's an AES paper on it, too. Give me a minute to look.

newusername
03-13-2008, 02:53 AM
"If you have experienced real stereo imaging..."

Nope, never. Thanks for the contribution.

"Imaging is a psychoacoustic effect."

Yeah, and the Haas effect is a part of that.

edit: I want to be clear that I am not talking about the creation of a phantom center channel just with mids in the rear and tweeters in the front. For the Haas effect to be relevant, there must also be a source in the front covering a bandwidth at least equal to that of the source in the rear. I am talking about the use of rear fill to enhance output with minimal degradation to the imaging generated along the horizontal axis from the sources in the front.

oldschool4me
03-13-2008, 02:59 AM
That is your opinion and differs with many. Aside from the vehicles (and homes and professional applications) where it has been used successfully.

If you follow the steps outlined, I think you will feel differently. Have you tried this? Have you listened to anything using a similar setup? Do you have information that directly disproves what I have outlined above?

Pretty sure there's an AES paper on it, too. Give me a minute to look.

i will let you take over, you explain things better than i do. they are misunderstanding what im saying.
im waiting to see some sq comp installs with no rear fill. links of some please. if rear fill is of no factor then why is it there??

James Bang
03-13-2008, 03:04 AM
been into audio for about 17 years and will never understand this. its like having a home theater system with 2 speakers. to me front and rear is just as important as left and right. might as well be mono imo. maybe its just a few of us that think this way idk.

apples and oranges.

i will let you take over, you explain things better than i do. they are misunderstanding what im saying.
im waiting to see some sq comp installs with no rear fill. links of some please. if rear fill is of no factor then why is it there??

Why don't you show these many rear fill sq comp cars.

newusername
03-13-2008, 03:25 AM
Well, for the sake of it.

Richard Clark's GN (not built by him, of course)
Harry Kimura's Acura Legend
And a ton of other cars built by SpeakerWorks (including the VW Beetle I alluded to earlier).

Those are the notable ones I know of, but there are others as well. Lots of threads out there on this subject already, although not many on this forum.

oldschool4me
03-13-2008, 07:06 AM
http://www.cardomain.com/ride/2384126
http://www.jbl.com/car/featured/installs/tundra_pics/subs_interior.jpg
just look around if you want to see more pics or pick up a magazine. not hard to find lol.

a quote from crutchfield adviser.

"Adjusting for rear fill
Once you have your front speakers installed to your liking, you'll want to make sure that your rear speakers are doing their part to create an ideal soundstage. While personal taste plays a role here, most experts agree that you should adjust the volume level for rear speakers so that you're barely conscious of their presence.

While your front speakers should give you the best midrange and high frequencies possible, your rear speakers can be conventional coaxials or low frequency drivers. Their purpose is to add ambience and depth to your forward soundstage. If they reveal too much high frequency information, they'll "pull" the stereo image to the rear of your vehicle, away from where you want it."


here is another quote

A2507 THE ENERGY TIME CURVE
By Richard Clark

Rear Fill
Even if we were able to achieve 50 mS of reverb time in a car, that amount would only be about one
fourth of the minimum required of a good sounding room. This lack of reverb time is the reason why some
car audio enthusiasts install extra speakers in the rear of the car. When such speakers are properly
mounted and driven by signals low enough in level (preferably on a digital delay), they can enhance the
effect of ambience that is usually lacking in cars. Ideally, the implementation of such speakers contributes
to the often-misunderstood IASCA term "rear fill."
In a good sounding rear filled system, the speakers mounted in the rear of the car should be acoustically
transparent. In other words, they should not be noticeable. A good sounding rear filled system should
cause the front-seated listeners to sense that there is a large open space to their rear. The word "fill" is
used here to refer to addition of reverberant energy to the listening environment. It is this decaying energy
that imparts ambience and the feeling of spaciousness into a sound system

why is a midbass a bad idea for rear fill again? dont knock it til you try it!!! lol
like i said before im not taking away from the importance of freq range for the front stage and not saying to take away from one location and put it in another. just that a midbass rear fill is important and if done propery like devildriver stated, improves the sound of a system. this may not be important to some people just the same as some people dont care to have an hd tv either and say there is no difference and i really dont care. just expressing my opinion and trying to help someone out with information that i have gathered in my experience. people just like to pick people apart and act like they know more than everyone. they would probably sit here and argue with wayne harris about car audio and what he should have done to make Terminator sound better and many are reading this wondering WTF is Terminator. get a grip people. here is a link for those who dont know.
http://www.termpro.com/showcars/terminator/terminator.html
oh and wait.... wait..... whats that in the pic?? below the subs?? ahhhh ahhhh. its a midbass set up. woooow imagine that???? now send him an email and tell him how dumb you think he is for doing such a retarted thing.
im done with this thread and im out.

newusername
03-13-2008, 10:30 AM
I wouldn't necessarily use Crutchfield as a reference on much. I find their information to be aimed at perpetuating misunderstandings that bring in dollars.

The person who first turned me on to this concept was a guy who goes by the name of werewolf on DIYMA and ECA. I did a lot of reading from there and some listening. Thus my stance here.

BrianChia
03-13-2008, 11:04 AM
"If you have experienced real stereo imaging..."

Nope, never. Thanks for the contribution.

"Imaging is a psychoacoustic effect."

Yeah, and the Haas effect is a part of that.

edit: I want to be clear that I am not talking about the creation of a phantom center channel just with mids in the rear and tweeters in the front. For the Haas effect to be relevant, there must also be a source in the front covering a bandwidth at least equal to that of the source in the rear. I am talking about the use of rear fill to enhance output with minimal degradation to the imaging generated along the horizontal axis from the sources in the front.

No, I had not read your post and none of mine weren't directed at you. Those who typically argue in favor of rear fill probably have NOT experienced real stereo imaging. I'll admit it, you sound like you have a lot more experience in "SQ" car audio than me and I learned a few things when I read your outline. But I've still never heard a convincing stereo image from multi-point sources, including "SQ" installs with supposedly proper time delay correction. I would love to read that AES paper if you have it. :)

dwc
03-13-2008, 04:24 PM
...you have a small 6.5" driver up front. You play it down to the crossover point but obviously lack the output you're looking for. Good news! You may keep it in the current bandwidth, add large midbass drivers in the rear, keep the difference in front/rear arrival times below 30 ms, lowpass below the frequencies at which IID becomes prominent, EQ out any unevenness, and gain output with no effects on localization...

Good points and acknowledged. I am now on the same page as you, and may have misunderstood earlier when I took it to mean having the 6.5's themselves in back.

oldschool4me
03-14-2008, 12:47 AM
I wouldn't necessarily use Crutchfield as a reference on much. I find their information to be aimed at perpetuating misunderstandings that bring in dollars.

The person who first turned me on to this concept was a guy who goes by the name of werewolf on DIYMA and ECA. I did a lot of reading from there and some listening. Thus my stance here.

yes i know but the info stated was general on the subject.

pikers
03-17-2008, 10:09 PM
hmmmm interesting. not a fan of that idea at all.

Midbass is probably the hardest thing to do well. Good amplifiers will exhibit the ability to control a driver, without stressing it or causing too much midbass bloom. In fact, RF is known for exhibiting this control and always has been. The fact that this seems to be a revelation in the CA&E review is a little puzzling TBH.