hi this is my first time on this forum. I'm kind of new to diy speakers, but i've done a project before. I have a pair of 3 ways I made at home, and i'm very happy with the sound from 800Hz and up, but the bass isn't really there. I'd like to change my bass speakers to something else- either use multiple 5" speakers or a speaker 6.5" or bigger. The Tweeter and mid are 89dB. Ideally it would be great if I didn't need any special crossover or anything like that for the woofer (has a fairly flat frequency response) and would sound good especially for acoustic jazz music, but also great in rock and other stuff I listen to.. Under $40 per driver.. I'm already considering the peerless csx (6.5") but it would be nice if I could spend less than that somehow.. thanks in advance
Not sure on driver choice, but I do know that using multiple 5" woofers would net you a louder sound, however, with your 89dB. constraint this wouldn't matter. You should use a box design program for your driver, to calculate required volume and vent length (if needed). Right now, I'm using a T-line with two 5.25" drivers (I added the second after my dissapointment in bass response, fixed comb filter effect as well). So, I guess you could go for a 6.5" driver, keeping in mind to have an fs around 30-40Hz. minimum. My Audax 5.25"ers are 56.1Hz. Not the bass I want for stereo, however, I can make up for this in my HT with a Sonotube sub. 😀
why should the fs be between 30 and 40Hz? How does this affect the sound? My current bass speakers have an fs around 56, and they were ok.. but since i'm changing them it would be nice to get deeper 🙂
small bass
imao..
the Fs should be as low as u want to go because after that it rolls off ofcourse.12db/ or 24db etc per octave
u can operate subs below their resonance but u get distortions and ur forcing somthing that they dont *want* to do
sealed boxes raise the Fs of ur speakers this is called Fb i think.
🙂
imao..
the Fs should be as low as u want to go because after that it rolls off ofcourse.12db/ or 24db etc per octave
u can operate subs below their resonance but u get distortions and ur forcing somthing that they dont *want* to do
sealed boxes raise the Fs of ur speakers this is called Fb i think.
🙂
Well, naturally a driver that is proprietarily producing lower freq. regions will be less likely to distort. IMHO, the sound will be much nicer, harmonically. What drivers are you already using, maybe you could wire those with other matching drivers (preferrably same manf..and model..).
Another idea would be, you purchasing whichever driver(s) you wanted and building entirely new cabinets (matching with current), connect the drivers to a sub-amplifier (HT-style) and placing your current box on top of this.
Another idea would be, you purchasing whichever driver(s) you wanted and building entirely new cabinets (matching with current), connect the drivers to a sub-amplifier (HT-style) and placing your current box on top of this.
I have parts express silk dome tweeters, and technics mids I salvaged from a MASSIVE pair of speakers! (sound great!).. These two mate together well, but i'm not sure about which woofer to use. There are sooo many different kinds.. I use this program called win isd to model my boxes, and i've punched in a whole bunch of different ts parameters to see what kind of tuning frequency i'll get. Eventually this system will have a sub, but i'd like to get decent low-end extension in the mean time, so maybe 38-40Hz tuning would be good..
Most likely I will end up building different cabinets anyways. I'm toying with a couple different ideas- maybe even a transmission line. A T line won't go the deepest, but since it is tuned to the Fs of the speaker and is usually a tight bass sound, that might be my best bet (as opposed to putting the driver in a sealed box which would give me a higher F3)..
i'm rambling..
TIA
Most likely I will end up building different cabinets anyways. I'm toying with a couple different ideas- maybe even a transmission line. A T line won't go the deepest, but since it is tuned to the Fs of the speaker and is usually a tight bass sound, that might be my best bet (as opposed to putting the driver in a sealed box which would give me a higher F3)..
i'm rambling..
TIA
t line
a t-line can easily do 40hz but lower = LONG length. about 1.7meteres is ok folded in half
i personaly dont trust t line boxes unless u copy some one elses idea.
ported and sealed is more easier to model.
40hz tuning is fine unless u run bass test cds..
music has little below 30hz(cooledit2000 shows this)
a t-line can easily do 40hz but lower = LONG length. about 1.7meteres is ok folded in half
i personaly dont trust t line boxes unless u copy some one elses idea.
ported and sealed is more easier to model.
40hz tuning is fine unless u run bass test cds..
music has little below 30hz(cooledit2000 shows this)
T lines are definitely harder to make, but there are advantages:
smoother rolloff of the low end (as opposed to ported which drops off like a rock below the tuning frequency)
tight bass sound
higher efficiency than sealed boxes
I'm not sure I understand what you're saying about music though.. Music doesn't play much below 40Hz?? How about the Titanic album? Just a thought..
smoother rolloff of the low end (as opposed to ported which drops off like a rock below the tuning frequency)
tight bass sound
higher efficiency than sealed boxes
I'm not sure I understand what you're saying about music though.. Music doesn't play much below 40Hz?? How about the Titanic album? Just a thought..
Believe me, for a 6 1/2" speaker, the lowest you want to go is 40 Hz. and that is with a ported speaker only.
It is a question of how much air the speaker can move. A certain amount of air must be moved by the speaker to produce a certain bass note at a certain frequency. The volume of air moved is the area of the speaker cone times the excursion of the cone.
In a sealed enclosure, the speaker must move the air all by itself. In a ported enclosure, the port helps the speaker so that the volume of air being moved, by the action of the port, is up to four times greater than the what the cone is moving. If the port is tuned to the F3 of the speaker, then the output of the port is greatest there.
A transmission line has port output to help the speaker, but generally the port output is less than the ported.
The cone area of a 6 1/2" speaker, at most, is 24 square inches. The cone excursion is likely to be no more than 1/4 inch. That means the volume displacement is 6 square inches.
If 40 Hz is the lowest note we aim for, and we construct a ported box tuned to 40 Hz, then we can multiply that volume displacement by 4. That brings us up to 24 cubic inches.
Please note the chart in the first post of the following thread. In a Windows machine, you might have to hit F11. It is the volume of air necessary to produce certain bass notes at certain SPLs in a normal room.
http://www.diyaudio.com/forums/showthread.php?threadid=5668&highlight=SPL+chart+displacement
We see that at 40 Hz, 24 cubic inches will produce about 106 dB SPL, (you have to estimate between 12 and 32 sq. inches). If your speaker is at 87 dB@1Watt/1M at 40 Hz, that is the equivalent of running about 80 or 90 watts through it.
In short, IF you are able to construct a ported speaker that smooth bass response when tuned to 40 Hz, then you will have good bass output, (106 dB) with a 6 1/2" speaker when 80 or 90 watts are running through it. To construct a box with a port tuning of 30 Hz or lower will yield decreased SPL output, and remember, the lower you go, the louder it has to be to be heard. 40 Hz is a good target for a 6 1/2" speaker.
Now you know why subwoofers are generally 10" or larger with very long excursions-1/2" or longer from center to peak. That is 1 inch front-to-back. To go lower, the subwoofer must move a LOT of air.
By the way, the lowest note the bass guitar puts out with normal tuning-which is the lowest note possible on a lot of popular music-is 42 Hz. Anything lower than that is normally produced by keyboards synths, etc. So 40 Hz really is the lowest note on a lot of popular music. It is a good target to aim for.
It is a question of how much air the speaker can move. A certain amount of air must be moved by the speaker to produce a certain bass note at a certain frequency. The volume of air moved is the area of the speaker cone times the excursion of the cone.
In a sealed enclosure, the speaker must move the air all by itself. In a ported enclosure, the port helps the speaker so that the volume of air being moved, by the action of the port, is up to four times greater than the what the cone is moving. If the port is tuned to the F3 of the speaker, then the output of the port is greatest there.
A transmission line has port output to help the speaker, but generally the port output is less than the ported.
The cone area of a 6 1/2" speaker, at most, is 24 square inches. The cone excursion is likely to be no more than 1/4 inch. That means the volume displacement is 6 square inches.
If 40 Hz is the lowest note we aim for, and we construct a ported box tuned to 40 Hz, then we can multiply that volume displacement by 4. That brings us up to 24 cubic inches.
Please note the chart in the first post of the following thread. In a Windows machine, you might have to hit F11. It is the volume of air necessary to produce certain bass notes at certain SPLs in a normal room.
http://www.diyaudio.com/forums/showthread.php?threadid=5668&highlight=SPL+chart+displacement
We see that at 40 Hz, 24 cubic inches will produce about 106 dB SPL, (you have to estimate between 12 and 32 sq. inches). If your speaker is at 87 dB@1Watt/1M at 40 Hz, that is the equivalent of running about 80 or 90 watts through it.
In short, IF you are able to construct a ported speaker that smooth bass response when tuned to 40 Hz, then you will have good bass output, (106 dB) with a 6 1/2" speaker when 80 or 90 watts are running through it. To construct a box with a port tuning of 30 Hz or lower will yield decreased SPL output, and remember, the lower you go, the louder it has to be to be heard. 40 Hz is a good target for a 6 1/2" speaker.
Now you know why subwoofers are generally 10" or larger with very long excursions-1/2" or longer from center to peak. That is 1 inch front-to-back. To go lower, the subwoofer must move a LOT of air.
By the way, the lowest note the bass guitar puts out with normal tuning-which is the lowest note possible on a lot of popular music-is 42 Hz. Anything lower than that is normally produced by keyboards synths, etc. So 40 Hz really is the lowest note on a lot of popular music. It is a good target to aim for.
Bonsai:
By your opening post, I get the impression that your box is already built. You want to substitute a driver for the one that is already in your 3 way speaker at home?
Anyway, that Peerless CSX 6 1/2 " you mentioned would be a good choice in a 1 cubic foot box tuned to 40 Hz. You might have to run a little more than 80 watts through it to get 106 dB, since it is only 87 dB efficient at the midpoint, but it is a good choice nonetheless. Not too many speakers are going to be more than 87 dB sensitive, anyway.
One more thing. The Peerless CSX line has a symmetrical magnetic field. Other speakers have it as well, but Peerless CSX line all have it. this prevents a strange phenomenon where, near the tuning frequency, the cone moves all the way to the end of it's travel and clips off half the wave form. Not eery speaker does this, but with a symmetrical magnetic field like the Peerless, you can be certain that it will not do this.
By your opening post, I get the impression that your box is already built. You want to substitute a driver for the one that is already in your 3 way speaker at home?
Anyway, that Peerless CSX 6 1/2 " you mentioned would be a good choice in a 1 cubic foot box tuned to 40 Hz. You might have to run a little more than 80 watts through it to get 106 dB, since it is only 87 dB efficient at the midpoint, but it is a good choice nonetheless. Not too many speakers are going to be more than 87 dB sensitive, anyway.
One more thing. The Peerless CSX line has a symmetrical magnetic field. Other speakers have it as well, but Peerless CSX line all have it. this prevents a strange phenomenon where, near the tuning frequency, the cone moves all the way to the end of it's travel and clips off half the wave form. Not eery speaker does this, but with a symmetrical magnetic field like the Peerless, you can be certain that it will not do this.
boxes
I do already have a box built. I'm having problems with the current woofer rattling (it's in a box that's too big I think) and it bottoms out, so I want to either find another driver that will work well in those boxes, or make new boxes. As a matter of fact, my boxes are 1.02 cubic feet, so maybe the csx would be perfect for it! Just a matter of getting the right port diameter and length.
As far as power, I have a 35W X 2 Sony Integrated from 1973. It seems very powerful.. Do you think this would be enough power?
and the peerless would be 89.5 dB sensitivity with the ported box, right? TIA
I do already have a box built. I'm having problems with the current woofer rattling (it's in a box that's too big I think) and it bottoms out, so I want to either find another driver that will work well in those boxes, or make new boxes. As a matter of fact, my boxes are 1.02 cubic feet, so maybe the csx would be perfect for it! Just a matter of getting the right port diameter and length.
As far as power, I have a 35W X 2 Sony Integrated from 1973. It seems very powerful.. Do you think this would be enough power?
and the peerless would be 89.5 dB sensitivity with the ported box, right? TIA
The Peerless 850122 is listed as 86.5 dB, midpoint. I would round that out to 87 dB.
WinISD shows that, put into a 1.05 du ft box and tuned to 40 Hz, it is 1 dB down at 40 Hz. So that is 85 or 86 dB at 40 Hz. At 40 watts and 40 Hz, your speaker will put out 102 dB each, not counting any extra help from the room-very important.
So both of them together will play at 108 dB at 40 Hz, driven by 40 watts each. The excursion is (+ or - )5.5 mm-almost 1/4". There might be slightly more sensitive drivers out there, but don't forget such matters as Fs or cone excursion.
The Peerless might not be the "perfect" woofer, but the two of them together will pack a good bass punch when driven by your 35 watt per channel receiver. I would spend a little time looking among Audax and others. I would not call the Peerless "perfect", I would characterize it as "quite workable". And maybe the best for your setup, but let's be open to options.
WinISD shows that, put into a 1.05 du ft box and tuned to 40 Hz, it is 1 dB down at 40 Hz. So that is 85 or 86 dB at 40 Hz. At 40 watts and 40 Hz, your speaker will put out 102 dB each, not counting any extra help from the room-very important.
So both of them together will play at 108 dB at 40 Hz, driven by 40 watts each. The excursion is (+ or - )5.5 mm-almost 1/4". There might be slightly more sensitive drivers out there, but don't forget such matters as Fs or cone excursion.
The Peerless might not be the "perfect" woofer, but the two of them together will pack a good bass punch when driven by your 35 watt per channel receiver. I would spend a little time looking among Audax and others. I would not call the Peerless "perfect", I would characterize it as "quite workable". And maybe the best for your setup, but let's be open to options.
By the way, given the fact that you already have your box built, I would add that you might actually end up getting bass under 40 Hz, after all.
Every room has modes, etc. These measurements are for placing the speaker against a wall on a floor in a room of infinite size-not realistic, but just a guideline.
Your room might have a mode that suppresses frequencies in the 30 or 40 Hz range. Or it might increase it. I don't know if you have any measuring equipment, but you might find that your room has a mode which enhances output in the 25 to 40 Hz range. In which case, you would be well advised to tune your speakers lower.
One of the nice things about ported speakers is that an adjustment in port length is all that is necessary to tune the box and get a different response.
By the way, I would just add something about that 108 dB for both channels driven. Because bass is omnidirectional, (therefore difficult to pinpoint the source), it has become recording practice for some time now to engineer the deep bass of a recording so both channels carry it. That way, one loudspeaker does not have to carry the load itself. There is no law that they must do this, and even into the 1970's, some engineers were putting all the bass on one channel, but it has been general practice to spread it to both channels for some time. So for all practical purposes, in the bass region, both speakers will be working together playing the same material, most of the time. That is why you can sum the output up as both channels driven. The stereo separation comes above the bass range, most of the time.
Every room has modes, etc. These measurements are for placing the speaker against a wall on a floor in a room of infinite size-not realistic, but just a guideline.
Your room might have a mode that suppresses frequencies in the 30 or 40 Hz range. Or it might increase it. I don't know if you have any measuring equipment, but you might find that your room has a mode which enhances output in the 25 to 40 Hz range. In which case, you would be well advised to tune your speakers lower.
One of the nice things about ported speakers is that an adjustment in port length is all that is necessary to tune the box and get a different response.
By the way, I would just add something about that 108 dB for both channels driven. Because bass is omnidirectional, (therefore difficult to pinpoint the source), it has become recording practice for some time now to engineer the deep bass of a recording so both channels carry it. That way, one loudspeaker does not have to carry the load itself. There is no law that they must do this, and even into the 1970's, some engineers were putting all the bass on one channel, but it has been general practice to spread it to both channels for some time. So for all practical purposes, in the bass region, both speakers will be working together playing the same material, most of the time. That is why you can sum the output up as both channels driven. The stereo separation comes above the bass range, most of the time.
I think a plane is a little louder than that. I do believe that as of 1980 or so, Deep Purple held the Guiness Book Of World Records for most sustained SPL at a concert-130 dB. Several people in the front row were reported to have passed out. However, considering rock concerts of the seventies, it might be presumptuous to assume they passed out because of the SPL level.
One audio writer went to his kid's junior high school dance as the parent in charge and brought his audio measuring equipment. He measured the DJ's average output for a three hour dance as 105 dB, which he thought was too loud for a sustained time. Remember, this is a man who writes about audio, not some occasional music listener.
So overall, I would say that 108 dB was very loud, far louder than most people would care to play the stereo for any sustained length of time.
I wouldn't go out and spend money on a new receiver unless I felt I needed more power, the music started sounding strained at the volumes I played it, or I wanted remote control. Otherwise, stick with what you have. At some point when you decide to get a new receiver, buy one with over 100 watts per channel. They are only a few bucks more than the others.
For a long time, most receivers were only 20 watts per channel. That is because 20 watts was enough to drive speakers louder than most people wanted to go.
One audio writer went to his kid's junior high school dance as the parent in charge and brought his audio measuring equipment. He measured the DJ's average output for a three hour dance as 105 dB, which he thought was too loud for a sustained time. Remember, this is a man who writes about audio, not some occasional music listener.
So overall, I would say that 108 dB was very loud, far louder than most people would care to play the stereo for any sustained length of time.
I wouldn't go out and spend money on a new receiver unless I felt I needed more power, the music started sounding strained at the volumes I played it, or I wanted remote control. Otherwise, stick with what you have. At some point when you decide to get a new receiver, buy one with over 100 watts per channel. They are only a few bucks more than the others.
For a long time, most receivers were only 20 watts per channel. That is because 20 watts was enough to drive speakers louder than most people wanted to go.
My dad's 901s are apparently supposed to hit up to 116dB....
Suffice to say that I have never, ever cranked them allll the way. At about half-volume on receiver and pre-amp my lights begin to flicker on and off...Yes 901s! BOSE! IMO 108dB. is either bragging rights or, head room...head room is a very good thing. I recommend Audax unless, your budget permits more, but with my experience with Audax; they permit a lot of sound at a lowww price.
Suffice to say that I have never, ever cranked them allll the way. At about half-volume on receiver and pre-amp my lights begin to flicker on and off...Yes 901s! BOSE! IMO 108dB. is either bragging rights or, head room...head room is a very good thing. I recommend Audax unless, your budget permits more, but with my experience with Audax; they permit a lot of sound at a lowww price.
spl
ok so you're telling me i'll have plenty of spl.. great! I don't usually listen to my music particularly loud, unless I hear some really cool bass passage in a jazz song or something and i'll just kick it up a notch.. lol those people in the 70's definitely didn't pass out from the spl 🙂 we all know it was something else.. haha.. But yeah I think i'll go with the csx's.. it would be cool if I could find some current commercial speaker design with the 6.5" csx in it, so I could check it out.. I recently noticed the Mtm made by NHT called the M6 (www.nhthifi.com). It looks like it has dual csx 6.5" speakers.. is there some way I can find out for sure if they are really csx's? I could always write nht, but who knows if they would actually tell me! Thanks.. Also, i'd like to start getting some ideas ready for a crossover for this.. I want to cross it over at 800Hz, using a butterworth topology (to make it the same as my mid and tweeter section) at the first order. Is there any other circuit I should add besides this? Like maybe something for impedance compensation or something like that? Thanks again
ok so you're telling me i'll have plenty of spl.. great! I don't usually listen to my music particularly loud, unless I hear some really cool bass passage in a jazz song or something and i'll just kick it up a notch.. lol those people in the 70's definitely didn't pass out from the spl 🙂 we all know it was something else.. haha.. But yeah I think i'll go with the csx's.. it would be cool if I could find some current commercial speaker design with the 6.5" csx in it, so I could check it out.. I recently noticed the Mtm made by NHT called the M6 (www.nhthifi.com). It looks like it has dual csx 6.5" speakers.. is there some way I can find out for sure if they are really csx's? I could always write nht, but who knows if they would actually tell me! Thanks.. Also, i'd like to start getting some ideas ready for a crossover for this.. I want to cross it over at 800Hz, using a butterworth topology (to make it the same as my mid and tweeter section) at the first order. Is there any other circuit I should add besides this? Like maybe something for impedance compensation or something like that? Thanks again
You want hi-fi bass? You use Impedance Eq., Eq. now, Eq. it all the way! Okay, not too much Eq, but you know...I like butterworths, that's what I'm using...Not sure about those NHTs though. I though NHT designed their own drivers..?
nht
I do know a little about nht.. From what i've heard, they used a slightly modified Seas tweeter in their model 2.9 and 3.3.. not sure about the other stuff though.. But yeah, as far as my design, i'm gonna stick to first order butterworth, and maybe throw an impedance eq circuit on there.. Does that have any affect on the speaker's performance other than lowering the impedance? It looks like there is an impedance peak that's over 16 ohms for the csx 6.5, and it stays a hair under 8 ohms up to 1000 Hz. The peak looks like it's around 40Hz.. How do I go about designing the impedance eq for this speaker? TIA
I do know a little about nht.. From what i've heard, they used a slightly modified Seas tweeter in their model 2.9 and 3.3.. not sure about the other stuff though.. But yeah, as far as my design, i'm gonna stick to first order butterworth, and maybe throw an impedance eq circuit on there.. Does that have any affect on the speaker's performance other than lowering the impedance? It looks like there is an impedance peak that's over 16 ohms for the csx 6.5, and it stays a hair under 8 ohms up to 1000 Hz. The peak looks like it's around 40Hz.. How do I go about designing the impedance eq for this speaker? TIA
Not a problem, I use this sites calculators for most of my work on speakers. www.lalena.com click on DIY audio and scroll down. Here's a quickie link to the Impedance Eq. calculator. calc
Here's the Help section for Impedance Eqs. It explains on what and how an impedance eq. works.
Help
Post an impedance curve?
Good luck man!
Here's the Help section for Impedance Eqs. It explains on what and how an impedance eq. works.
Help
Post an impedance curve?
Good luck man!
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