hi pass and low pass - explain please
- Thread starter stevem5000
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ahh you definately couldnt do number 1 and if you dont want booming bass why go for a sub?
you dont have to use a high pass cut that would be used for door speakers etc... to keep the low ranges out thereby giving you more room to push you levels without damage to or distortion from your speakers
as for the difference between them those numbers ie 50-120 and 50-750 are measured in Hertz otherwise known as the number of cycles of a pulse of a signal or wave within a second lower Hz numbers are a greater slower band and a lower tone where as higher hz numbers are the opposite a high pass filter lets everything above the set number to pass though the gate everything else below it is cut out so if you were to put in a high pass at lets say 300Hz most deep bass anything youd put through a sub definately and the far lower extremeties of the homan voice would be cut out of your output signal. reason you cant go for option 1 is because that would be feeding your sub from 500Hz to about 15000Hz (depending on music) and subs max frequencie ranges are usually well below 1000Hz so you wouldnt get any bass at all and you would be doing damage to your sub go for option 2 set a low pass at 120Hz or so
you dont have to use a high pass cut that would be used for door speakers etc... to keep the low ranges out thereby giving you more room to push you levels without damage to or distortion from your speakers
as for the difference between them those numbers ie 50-120 and 50-750 are measured in Hertz otherwise known as the number of cycles of a pulse of a signal or wave within a second lower Hz numbers are a greater slower band and a lower tone where as higher hz numbers are the opposite a high pass filter lets everything above the set number to pass though the gate everything else below it is cut out so if you were to put in a high pass at lets say 300Hz most deep bass anything youd put through a sub definately and the far lower extremeties of the homan voice would be cut out of your output signal. reason you cant go for option 1 is because that would be feeding your sub from 500Hz to about 15000Hz (depending on music) and subs max frequencie ranges are usually well below 1000Hz so you wouldnt get any bass at all and you would be doing damage to your sub go for option 2 set a low pass at 120Hz or so
helotaxi
5,000+ posts
Kilroy was Here
Most subs will not accurately reproduce sounds above 120 Hz and you really want your crossover (low pass) set much lower than that. The human ear is not very good at localizing sounds lower than 80 Hz. Since your subs will most likely be installed behind your listening position in the car, if they are playing frequencies higher than 80 Hz it will sound like all the bass is coming from behind you. Ideally your front stage speakers should be able to extend to less than 80 Hz and overlap or at least meet your subs' frequencies.
If your amp only has two channels, you will need two amps to run all of your speakers if you plan on using the active crossover in your amp. One amp would be high pass and run your front speakers and the other would be low-pass and run your sub(s). The function of a crossover (high- or low-pass) works exactly as it sounds. A low-pass lets frequencies below the crossover frequency pass and attenuates frequencies above it at a specified rate i.e. 12dB per octave. What this means is that every octave (doubling of frequency) you move above the low pass point the sound is 12dB less. dB is not a linear scale and every 3dB equals a doubling of power, so at 12dB down (160 Hz for a 80 Hz crossover point) there is 1/8 the power being output. A high pass crossover works the same but lets the high frequencies pass.
If your amp only has two channels, you will need two amps to run all of your speakers if you plan on using the active crossover in your amp. One amp would be high pass and run your front speakers and the other would be low-pass and run your sub(s). The function of a crossover (high- or low-pass) works exactly as it sounds. A low-pass lets frequencies below the crossover frequency pass and attenuates frequencies above it at a specified rate i.e. 12dB per octave. What this means is that every octave (doubling of frequency) you move above the low pass point the sound is 12dB less. dB is not a linear scale and every 3dB equals a doubling of power, so at 12dB down (160 Hz for a 80 Hz crossover point) there is 1/8 the power being output. A high pass crossover works the same but lets the high frequencies pass.
Maybe because there is low frequency musical information that his main speakers cannot reproduce? I don't really like "booming" bass either but would I ever build a system without a sub? Ummmmm, NO! I won't use a 15 or probably even a 12 and definitely won't be running 1 kW of power to it (them) but I will have a sub.
should have thought about it I will definately agree with you on that one
maylar
10+ year member
Electrical Weenie
Filters are for limiting the range of frequencies that go to your speakers or subs so they work in the range they were designed for.
Hi Pass means everything above a certain frequency goes through, everything below gets cut out. We use that to keep bass out of our main speakers.
Low Pass is the opposite - you use that to keep highs out of the subs. As already mentioned, 80 Hz or so is a good number for that.
Some amps come with both hi and lo filters so you can use them with either main speakers or subs. There will be a switch on them to allow you to select which filter to use. For subs you'll want the lowpass.
Hi Pass means everything above a certain frequency goes through, everything below gets cut out. We use that to keep bass out of our main speakers.
Low Pass is the opposite - you use that to keep highs out of the subs. As already mentioned, 80 Hz or so is a good number for that.
Some amps come with both hi and lo filters so you can use them with either main speakers or subs. There will be a switch on them to allow you to select which filter to use. For subs you'll want the lowpass.
XDrkmanX
10+ year member
Time to Duel B*tches
So I should set my HI-Pass to the cut off point of my Low-Pass?
helotaxi
5,000+ posts
Kilroy was Here
Not necessarily. You should set it to whatever gives the smoothest transition between your high frequency speakers and the sub. This could mean that they are staggered a bit (high-pass higher than low-pass). Because the filter has a roll-off rather than a straight cutoff, both sets of speakers will be playing the same frequencies right around the crossover point. If they are set to the same frequency, this over lap could (and usually does) leave a bump in the frequency response of the system. With the bump occuring right at the transition between the sub and mid-bass this will manifest itself as a kind of one note drone right at the crossover frequency. That drone can be quite annoying.
- Thread Starter
- #8
Sorry I couldn't get back sooner...
Thanx for the explains...really helps...
Couple of questions came up...
Much of what I listen to happens in the mid range frequencies, classical guitar for example...
My home system consists of a pair of JBL Studio Monitors, circa 1968 or so...it's a bookshelf 12" and a 5" with the crossover at 3000hz, (I think)...in their day they were considered very fine speakers...this is what I am used to listening to...
This system is what I would like to duplicate, more or less, in my truck...
It's a 2000 Frontier ext cab with 2 small jump seats that I have removed and built boxes that fit right in the space the jump seats occupied...
The boxes currently holds a pair of Boston Acoustic NX97's...
There is about .4 cu ft left in these boxes and I found 3 brands of 8" subs that are supposed to cut off at 4-500 hz and supposedly work anywhere from .3 to .5 cu ft...
I am thinking getting a pair of 8" Audiobahn's and drive them with a small amp...
The question is, now that I understand high-pass and low-pass, do I get an amp with an internal crossover of about 4-500hz that is adjustable (this is hard to find)...
Or do I get a seperate crossover and 2 amps and have the hu drive the crossover first then to each amp and the appropriate speakers...(more expensive)...This option would eliminate the low freqs going to the NX97's....but the same low freqs would still be going to my front speakers which are Boston Acoustic RC620's...
I will have to say that I am very satisified with the current sound...all speakers are driven by my Pioneer DEH-P7500, no amps at all in the system...
All in all I have a pretty good sounding system for about $800.00...
I'm not interested in booming bass, nor loud volume...just a good full range system...
I anxiously await any and all comments...
Regards
Steve
Thanx for the explains...really helps...
Couple of questions came up...
Much of what I listen to happens in the mid range frequencies, classical guitar for example...
My home system consists of a pair of JBL Studio Monitors, circa 1968 or so...it's a bookshelf 12" and a 5" with the crossover at 3000hz, (I think)...in their day they were considered very fine speakers...this is what I am used to listening to...
This system is what I would like to duplicate, more or less, in my truck...
It's a 2000 Frontier ext cab with 2 small jump seats that I have removed and built boxes that fit right in the space the jump seats occupied...
The boxes currently holds a pair of Boston Acoustic NX97's...
There is about .4 cu ft left in these boxes and I found 3 brands of 8" subs that are supposed to cut off at 4-500 hz and supposedly work anywhere from .3 to .5 cu ft...
I am thinking getting a pair of 8" Audiobahn's and drive them with a small amp...
The question is, now that I understand high-pass and low-pass, do I get an amp with an internal crossover of about 4-500hz that is adjustable (this is hard to find)...
Or do I get a seperate crossover and 2 amps and have the hu drive the crossover first then to each amp and the appropriate speakers...(more expensive)...This option would eliminate the low freqs going to the NX97's....but the same low freqs would still be going to my front speakers which are Boston Acoustic RC620's...
I will have to say that I am very satisified with the current sound...all speakers are driven by my Pioneer DEH-P7500, no amps at all in the system...
All in all I have a pretty good sounding system for about $800.00...
I'm not interested in booming bass, nor loud volume...just a good full range system...
I anxiously await any and all comments...
Regards
Steve
helotaxi
5,000+ posts
Kilroy was Here
Just because the manufacturer says that the sub can play up to a certain frequency doesn't mean that it sounds good at that frequency. Also, imaging will suffer severely if you cross those subs over at 500hz. All the sound will seem to be coming from behind you. Not what you are looking for I would imagine. Because of the space required, you really can't expect your car setup to resemble your home system as far as layout and number of speakers and crossover points. You can get pretty much the same sound, you just have to have a slightly different approach.
Larger home speakers generally use a woofer (rather than a sub, there is a difference) with decent midrange extension. Add to that either a tweeter or an mid and a tweeter. All frequencies are divided by a passive crossover network. This works well because all the speakers are in front of you and the crossovers can be designed for the smoothest frequency response and a smooth transition between the different drivers.
Most car systems use a sub (crossed over somewhere below 80Hz with an active crossover and powered by its own amp), a midrange with decent midbass extension, and a tweeter. The highs are in front of you and the sub, because of space considerations, is usually somewhere behind you. Since you generally can't tell where frequencies below 80Hz are coming from, this isn't that big a deal. Getting a good transition between mid and tweet is pretty straightforward. A good component set or coaxial will take care of that. The trick is getting a good midbass transition between the mids and the sub.
How much are you willing to spend for a sub/amp combo? Once I know that I can you some specific suggestions.
Larger home speakers generally use a woofer (rather than a sub, there is a difference) with decent midrange extension. Add to that either a tweeter or an mid and a tweeter. All frequencies are divided by a passive crossover network. This works well because all the speakers are in front of you and the crossovers can be designed for the smoothest frequency response and a smooth transition between the different drivers.
Most car systems use a sub (crossed over somewhere below 80Hz with an active crossover and powered by its own amp), a midrange with decent midbass extension, and a tweeter. The highs are in front of you and the sub, because of space considerations, is usually somewhere behind you. Since you generally can't tell where frequencies below 80Hz are coming from, this isn't that big a deal. Getting a good transition between mid and tweet is pretty straightforward. A good component set or coaxial will take care of that. The trick is getting a good midbass transition between the mids and the sub.
How much are you willing to spend for a sub/amp combo? Once I know that I can you some specific suggestions.
- Thread Starter
- #10
Helotaxi-man...
The Audiobahns are about $60 each...
I am still looking for an amp, but I suspect it will be about $200...I'm not looking for a lot of power, remember, the rest of my speakers are driven off the hu only, no amps at all...
I have the boxes, just need to fit the subs into the box, run the wire etc...
So, that puts me at about $320 or so...say $375 by the time I'm done...
And all I want to do is put a foundation in my system...give the low end some "oooomph"...but not much...
Now, perhpas I am not going about this right...I have never listened to a system with subs installed in a car...only in the stereo stores, and it seems like the bass is always overpowering...too much...too strong...I get the salesman to tone it down a little, but it seems like there is a "disconnect" between the bass and the mids...maybe it's just me and the way I'm listening...maybe my expectations are out of alighnment...
So that's why I'm thinking to cross it at a higher point and maybe the transition will be smoother...anything that I get will be adjustable, so if it doesn't work like I would like to think it would, I just move the crossover point lower and lower until it does work correctly...
And then I think, I have about $800 in my system so far...can I really justify almost 50% more just for some bass???...hard decision...
I understand your description on the location, and I agree, but I also suspect that with the small cab on my truck, does speaker placement really matter that much???
Right now I tend to run the rear coax's slightly louder than the components in the front...it seems like my low end is slightly more "open" or "richer" of the 6x9's in the back than from my front components...
At any rate, whatever I do, if I really don't like it, I guess I can sell the stuff on eBay, take my hit...because I still like what I have...just trying to improve it a little...
Thanx for your comments...
It will be another day before I get a chance to respond...
Regards
STeve
The Audiobahns are about $60 each...
I am still looking for an amp, but I suspect it will be about $200...I'm not looking for a lot of power, remember, the rest of my speakers are driven off the hu only, no amps at all...
I have the boxes, just need to fit the subs into the box, run the wire etc...
So, that puts me at about $320 or so...say $375 by the time I'm done...
And all I want to do is put a foundation in my system...give the low end some "oooomph"...but not much...
Now, perhpas I am not going about this right...I have never listened to a system with subs installed in a car...only in the stereo stores, and it seems like the bass is always overpowering...too much...too strong...I get the salesman to tone it down a little, but it seems like there is a "disconnect" between the bass and the mids...maybe it's just me and the way I'm listening...maybe my expectations are out of alighnment...
So that's why I'm thinking to cross it at a higher point and maybe the transition will be smoother...anything that I get will be adjustable, so if it doesn't work like I would like to think it would, I just move the crossover point lower and lower until it does work correctly...
And then I think, I have about $800 in my system so far...can I really justify almost 50% more just for some bass???...hard decision...
I understand your description on the location, and I agree, but I also suspect that with the small cab on my truck, does speaker placement really matter that much???
Right now I tend to run the rear coax's slightly louder than the components in the front...it seems like my low end is slightly more "open" or "richer" of the 6x9's in the back than from my front components...
At any rate, whatever I do, if I really don't like it, I guess I can sell the stuff on eBay, take my hit...because I still like what I have...just trying to improve it a little...
Thanx for your comments...
It will be another day before I get a chance to respond...
Regards
STeve
maylar
10+ year member
Electrical Weenie
Nice speakers. Like KLH5's or Advent's.
Your main speakers should be the ones up front in your doors. This is where the midrange clarity, presence, and overall tonal quality of your system will come from. Spend the money to make them as good as you can afford. You should rely very little if at all on the rear ones. This is necessary to achieve any kind of decent stereo imaging. An amplifier is considered necessary if you expect to power some decent components. Coaxials on head unit power will disappoint you.
2-way or 3-way speakers all have some kind of passive crossover system. Coaxials use a simple capacitor to block lows from the tweeter. Components have a more sophisticated passive crossover network external (and somewhat adjustable).
The normal way to crossover car systems is to hipass the front speakers at 60-70 Hz and let the passive crossovers handle the transition from midrange to tweeter. The hipass is necessary to keep bass out of them, so they don't distort on peaks.
The subwoofer is lowpassed at 70-80 Hz with no external passive components, just the amp's adjustable filter. The amount of overlap you use between subs and main speakers depends on your taste and the midbass response of the main speakers.
With sealed sub box in the cab, you won't need much power at all to make a pair of 8's fill in the lower octaves.
- Thread Starter
- #12
Dave...many thanx...
Much better understanding of what's going on...
I already have BA RC620's in the front...and I like them but I do NOT have them high-passed at all...My rears are BA NX97's...these are not high-passed either...and I have the balance adjusted slightly to the rear because I get slightly better bass from them...now I know why...
BUT, if I get the fronts and rears correctly high-passed, then the subs take care of what they are supposed to do with the correct low-pass for them...which can come from an amp, or a seperate crossover...
I do NOT have any amps in this system...I also don;t play it very loud...just comfortable...my Pioneer is driving them ok, I think...
I also think that the Pioneer has some crossover points in it, I will have to look in the book and see what I can find...never went looking for it...didn;'t know I needed it...
Now, considering I don;t play loud, and I don;t want booming bass like many of the kids I hear pulled up at the stoplight...
Do I need amps...realisticly...if so, I assume one 4 channel for the front's and rear and another amp for the bass...will amps improve the sound enough to justify the expense???...do I put a lot of $$$ into amps, are there brands I should stay away from...I won;t get top of line, (Alpine) etc something medium range price wise...
Thanx again all...
I've learned a LOT!!!!..//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
Steve
Much better understanding of what's going on...
I already have BA RC620's in the front...and I like them but I do NOT have them high-passed at all...My rears are BA NX97's...these are not high-passed either...and I have the balance adjusted slightly to the rear because I get slightly better bass from them...now I know why...
BUT, if I get the fronts and rears correctly high-passed, then the subs take care of what they are supposed to do with the correct low-pass for them...which can come from an amp, or a seperate crossover...
I do NOT have any amps in this system...I also don;t play it very loud...just comfortable...my Pioneer is driving them ok, I think...
I also think that the Pioneer has some crossover points in it, I will have to look in the book and see what I can find...never went looking for it...didn;'t know I needed it...
Now, considering I don;t play loud, and I don;t want booming bass like many of the kids I hear pulled up at the stoplight...
Do I need amps...realisticly...if so, I assume one 4 channel for the front's and rear and another amp for the bass...will amps improve the sound enough to justify the expense???...do I put a lot of $$$ into amps, are there brands I should stay away from...I won;t get top of line, (Alpine) etc something medium range price wise...
Thanx again all...
I've learned a LOT!!!!..//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
Steve
helotaxi
5,000+ posts
Kilroy was Here
Take a look at the Soundstream EGA500 amp available on clearance from Millionbuy.com . It is a 5 channel amp with crossovers built in for all of the channels. It is 25 watts to each of 4 channels for your high range speakers and 100 watts to 1 channel for a sub. 25 watts from a real amp will make a huge difference in the clarity of your high range speakers when compared to running them off the headunit.
I don't think you will be happy with the sound of those Audiobahn 8s. I would try a different company and probably only go with 1 sub, either a 10 or an 8. For an 8 I would look at the JL 8W0. For a 10 I would suggest the Elemental Designs eD10Kx. Both work in a really tiny box and will do well on the 100w sub channel of that Soundstream amp. They are both better choices than the Audiobahn for sound quality and either can be had for less than $80 if you shop around a bit for the JL (the eD is on sale at their site for $75 + shipping). You should be able to add a sub and full system amplification for less than $250 if you do the install yourself. The difference you will note will be night and day, trust me.
I don't think you will be happy with the sound of those Audiobahn 8s. I would try a different company and probably only go with 1 sub, either a 10 or an 8. For an 8 I would look at the JL 8W0. For a 10 I would suggest the Elemental Designs eD10Kx. Both work in a really tiny box and will do well on the 100w sub channel of that Soundstream amp. They are both better choices than the Audiobahn for sound quality and either can be had for less than $80 if you shop around a bit for the JL (the eD is on sale at their site for $75 + shipping). You should be able to add a sub and full system amplification for less than $250 if you do the install yourself. The difference you will note will be night and day, trust me.
- Thread Starter
- #14
I looked at the Soundstream VGA500 and its $589.00 on sale...
WAAAAYYYYYY too much...
BUT, the JL8w0 looks interesting...I'm downloading a PDF file on the specs now...
It looks like it will fit in the boxes I made ok...and at $80 a piece, the price is ok...
As far as 1 or 2 subs...I have the two boxes mounted in the space where kiddie seats fold out in the back...I don;t want another box in the back as I haul other stuff around behind the seats...I install computer networks and I usually have my laptop sitting behind me...
So I would get an amp for the bass that would handle both of them...
Went out to do some listening at Custom Sounds tonite...they are a high end store here in St Louis...about the only one...just want to get some better ideas on listening to some subs...but I don;t want to pay their prices...
Continueing to look, listen and learn...
I am considering the advice on the amps...gonna look at some of the other Soundstream models...
Thanx again guys...
Regards
Steve
WAAAAYYYYYY too much...
BUT, the JL8w0 looks interesting...I'm downloading a PDF file on the specs now...
It looks like it will fit in the boxes I made ok...and at $80 a piece, the price is ok...
As far as 1 or 2 subs...I have the two boxes mounted in the space where kiddie seats fold out in the back...I don;t want another box in the back as I haul other stuff around behind the seats...I install computer networks and I usually have my laptop sitting behind me...
So I would get an amp for the bass that would handle both of them...
Went out to do some listening at Custom Sounds tonite...they are a high end store here in St Louis...about the only one...just want to get some better ideas on listening to some subs...but I don;t want to pay their prices...
Continueing to look, listen and learn...
I am considering the advice on the amps...gonna look at some of the other Soundstream models...
Thanx again guys...
Regards
Steve
helotaxi
5,000+ posts
Kilroy was Here
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