Off to the lions pit
OK. This afternoon I go and set the litle sub into the hands of a couple of kids. I know this is a relative term but when your old enough to be their dad you call them kids. I guess I'm in that leauge compared to some of the guys on the forum to. No substitute for experience they say. But there is also no substitute for a discriminating ear. One of these gentlemen has listened to a sub I built him for a couple of months so he has a good reference at home.
Will see what this little puppy does with some more up to date music. These fellows like rap and hip hop if I have my info correct. So this will be quite a departure from the pounding this sub has been getting from the Organ CD's I've tried. Not that an organ CD is easy on a sub. Some of the stops on a large pipe organ have as much power as a jack hammer at close range. It's just that people are asking how it sounds with.....
I have classical, instrumental, orchestral, choral, even country and western has been tried. But no pop so far other than what was on the radio.
A good excuse to give it a whirl and I'll report back in when I get back tonight.
If the guys are happy maybe I'll encourage them to post their own thoughts.
Mark
OK. This afternoon I go and set the litle sub into the hands of a couple of kids. I know this is a relative term but when your old enough to be their dad you call them kids. I guess I'm in that leauge compared to some of the guys on the forum to. No substitute for experience they say. But there is also no substitute for a discriminating ear. One of these gentlemen has listened to a sub I built him for a couple of months so he has a good reference at home.
Will see what this little puppy does with some more up to date music. These fellows like rap and hip hop if I have my info correct. So this will be quite a departure from the pounding this sub has been getting from the Organ CD's I've tried. Not that an organ CD is easy on a sub. Some of the stops on a large pipe organ have as much power as a jack hammer at close range. It's just that people are asking how it sounds with.....
I have classical, instrumental, orchestral, choral, even country and western has been tried. But no pop so far other than what was on the radio.
A good excuse to give it a whirl and I'll report back in when I get back tonight.
If the guys are happy maybe I'll encourage them to post their own thoughts.
Mark
Survey says.....
Well the two gentlemen have given their verdict. I always knew this sub had taste. It hates rap!
But almost everything else it passed with flying colors. Rock, Punk, Techno, Classic Heavy Metal, Blues. You get the idea. From the frequency response it is fairly easy to see that as designed this little box works well down to 40hz. Much below that and it is not so happy. Stuffing may help a bit but that is still to be investigated.
Mark
Hey GM we have the same hairline but your box looks bigger.
Well the two gentlemen have given their verdict. I always knew this sub had taste. It hates rap!
But almost everything else it passed with flying colors. Rock, Punk, Techno, Classic Heavy Metal, Blues. You get the idea. From the frequency response it is fairly easy to see that as designed this little box works well down to 40hz. Much below that and it is not so happy. Stuffing may help a bit but that is still to be investigated.
Mark
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Hey GM we have the same hairline but your box looks bigger.
I forgot to post peaks on sine waves
The three of us tried various tracks and then they were talking frequency response per box. I played the test CD generated with WaveGen ( 30 hz to 100hz in 5hz increments ) and we sat in the car innards vibrating and such. It's interesting to find the resonant modes in a small vehicle. With a couple of people in the car the response is actually flatter ( a word I hope ) lets go with more even. Plus 2 minus 1db. We were peaking out at 112db easily with all of us very uncomfortable. No ear plugs. That level was driven with the stock head unit playing music not tones with another 18 volume points to go. So can go louder yes. Do I want it no! The box could use it's own amp as most things that suck the power like a dedicated amp. The most we pumped in was 10 watts that's with one set of eyes on the SPL meter and my four on the voltmeter.
I'm being challenged to do something similar for an 8 inch driver. Any requests?
Mark
The three of us tried various tracks and then they were talking frequency response per box. I played the test CD generated with WaveGen ( 30 hz to 100hz in 5hz increments ) and we sat in the car innards vibrating and such. It's interesting to find the resonant modes in a small vehicle. With a couple of people in the car the response is actually flatter ( a word I hope ) lets go with more even. Plus 2 minus 1db. We were peaking out at 112db easily with all of us very uncomfortable. No ear plugs. That level was driven with the stock head unit playing music not tones with another 18 volume points to go. So can go louder yes. Do I want it no! The box could use it's own amp as most things that suck the power like a dedicated amp. The most we pumped in was 10 watts that's with one set of eyes on the SPL meter and my four on the voltmeter.
I'm being challenged to do something similar for an 8 inch driver. Any requests?
Mark
Re: Survey says.....
Interesting, I wasn't aware rap had any low bass in their recordings. I mean the only rap I hear are the rap boom cars around here that sound like they die around a really loud/obnoxious ~50-60 Hz. The lowest sounding ones are the Mexican 'polka' boom cars/trucks/vans.
Not anymore, that's an old pic of me. I'm a 'cone head' now. Yeah, your box would barely fill up my HF horns Vb wise, not that there's any relevancy of course since they are both optimized for radically different apps.
GM
mwmkravchenko said:
Interesting, I wasn't aware rap had any low bass in their recordings. I mean the only rap I hear are the rap boom cars around here that sound like they die around a really loud/obnoxious ~50-60 Hz. The lowest sounding ones are the Mexican 'polka' boom cars/trucks/vans.
Not anymore, that's an old pic of me. I'm a 'cone head' now. Yeah, your box would barely fill up my HF horns Vb wise, not that there's any relevancy of course since they are both optimized for radically different apps.
GM
Hi DarpMalone
The driver is a rather important part of the equation in this type of a an enclosure. The right balance gets you a very small box with some outstanding qualities. Here is what I propose. I have on hand a couple of eight inch drivers. I'll test them and see what is what with them. Then I'll crunch the numbers for a couple of days and iff something interesting comes together I'll post it.
The other thing I promised for the car crowd is a real tapped horn that will work all the way down to about 16hz. It was briefly described in the beginning of this thread until Henkjan asked for the wee little one. The designs use a high quality driver because they give high quality sound. I'm a bit spoiled in that department. Once you hear bass done right the vast majority of subs sound like boom boxes. The larger horn is going into my car as my own permanent source of low end. The current baby box is for sale.
So that is the reasoning why I stick to the good drivers like the SDX7. Remember the SDX7 speced has the volume displacement of two of the drivers that you have asked me to look at. That is two for the price of one. More simple you'd need four normal 6 1/2" driver to equal one SDX7. That is the reason why I picked it. I have five different 6 1/2 " drivers on hand right now. The SDX7 is by far the best capable of giving you the most clean sound.
So enough tooting the horn. ( couldn't resist ) I have a couple of 8" in stock and I will play with them and see what gives.
Mark
The driver is a rather important part of the equation in this type of a an enclosure. The right balance gets you a very small box with some outstanding qualities. Here is what I propose. I have on hand a couple of eight inch drivers. I'll test them and see what is what with them. Then I'll crunch the numbers for a couple of days and iff something interesting comes together I'll post it.
The other thing I promised for the car crowd is a real tapped horn that will work all the way down to about 16hz. It was briefly described in the beginning of this thread until Henkjan asked for the wee little one. The designs use a high quality driver because they give high quality sound. I'm a bit spoiled in that department. Once you hear bass done right the vast majority of subs sound like boom boxes. The larger horn is going into my car as my own permanent source of low end. The current baby box is for sale.
So that is the reasoning why I stick to the good drivers like the SDX7. Remember the SDX7 speced has the volume displacement of two of the drivers that you have asked me to look at. That is two for the price of one. More simple you'd need four normal 6 1/2" driver to equal one SDX7. That is the reason why I picked it. I have five different 6 1/2 " drivers on hand right now. The SDX7 is by far the best capable of giving you the most clean sound.
So enough tooting the horn. ( couldn't resist ) I have a couple of 8" in stock and I will play with them and see what gives.
Mark
of course you realize that rap relies on the second and third order harmonic distortion and messy transient response inherient in bass reflex and acoustic suspension box designs to give it that "full" "thick" bass sound. So the cleaner your sound is the less "impressive" the bass will be in rap. But if your intelligent enough to design horn speakers, chances are you don't listen to much rap.
Hi brsanko
You are correct on two counts. Rap does rely on boxes with with high distortion components. A no I can't really stand the stuff. As for inteligence level I leave that up to you to decide. This design is presented for people to build it and listen. If you enjoy a clean realistic bass you get it.
Mark
You are correct on two counts. Rap does rely on boxes with with high distortion components. A no I can't really stand the stuff. As for inteligence level I leave that up to you to decide. This design is presented for people to build it and listen. If you enjoy a clean realistic bass you get it.
Mark
Neither rap, nor any other bass driven music rely on high distortion components to sound good (unless distortion sounds good to you). Nor does that explain why Mark's horn performed the way it did with rap music... I would imagine that @ moderate levels, the horn sounded great (better than a one note, distorted boom box would have sounded at the same SPL, playing the same material) You need to move more air and quickly dissipate heat in order to faithfully reproduce the music @ higher SPL.
I use a 12" peerless xxls sub in my car (not the loudest sub, but it can go louder than necessary), but more importantly, they are very low distortion subs. I power it with an extremely clean autotek BTS amp that can provide double the sub's RMS at 0.015% THD, so any distortion is being generated by the car itself. I'm not sure how low it goes in the car because I've never measured it, but it sounds fantastic with any music it's presented with, even rap
Mark, your design sounds very interesting... If you decide to design one for 8" drivers, I look forward to building one of my own.
I use a 12" peerless xxls sub in my car (not the loudest sub, but it can go louder than necessary), but more importantly, they are very low distortion subs. I power it with an extremely clean autotek BTS amp that can provide double the sub's RMS at 0.015% THD, so any distortion is being generated by the car itself. I'm not sure how low it goes in the car because I've never measured it, but it sounds fantastic with any music it's presented with, even rap
Mark, your design sounds very interesting... If you decide to design one for 8" drivers, I look forward to building one of my own.
Oh I'm sorry we must be morons. Do you have a school we could attend? Distortion doesn't sound good to me but niether does rap. Rap is not music, it is computer generated noise and distortion. The window rattling rib cage jaring "bass" noise in rap recordings is a very simple product of computer induced DISTORTION. Low quality enclosers (i.e. anything besides a horn) exgerates this effect. A truely low distortion clean sounding sub (i.e. a horn) will have an entirely different sound that will not have the desired effect, but despite this will be a more acurate rendering of what is actually in the recording. Any actual music (acoustic recording) will sound the way it did originally. If you don't have a horn sub you have no idea how clean, dynamic and distortion free a subwoofer can actually be!
Just a little trumpet toot or too
Hi DrpMalone
I don't put to much effort into saying how great things are with this design. A couple of gents tried it out. The one on the left promises to post his thoughts on the matter.
As for some of your comments they are well taken but I would add this little blurb.
You no doubt understand that to our ears a heavily distorted 2 and 3rd harmonic of the original note being played sounds like louder bass. In simpler terms if we have a low b flat from a 6 string bass we are looking at a fundamental of about 32hz. The vast majority of subs cannot really give you that note with out compression or loss of amplitude better described as sound pressure level. So what we hear is the 2nd harmonic 64hz and the third harmonic 128hz. It sounds impressive. But it's not the real low bass you'd hope for. This distortion is unfortunately there in most of the subs that I have worked with and requested by most of the people I do custom work for. You DarpMalone are a man after my own ideal of clean undistorted bass. Just that I have 22watts and not a heck of a lot of space to do it in.
Your system is interesting. I modeled it below and found with cabin gain in most midsized cars your maximum acoustical output is 112db. This is dictated by the diameter of the cone and the throw of the suspension. Not the available power. Once you hit these mechanical limits there is nothing that can be done to make it louder. Except add more drivers. Double the drivers and you get 3db more. You also need double the box.
I will humbly point you in the direction of post number 83
We were hitting sustained SPL of 112 and peaks of 114 with less than 15 watts. None of us wanted to go louder we had no hearing protection. The sub could go louder as shown in post # 6
http://www.diyaudio.com/forums/showthread.php?postid=1850643#post1850643
That is the difference between a normal box and even this little poor excuse for a horn. Efficiency. Just think about it two 6.5" drivers match your 10 in a box that is just over 22 liters. A cubic foot is 27 liters! A lot of thinking went into this design.
What this little box cannot do has all ready been presented. Below about 40hz it is out of it's happy space. It's passband is from 38hz to 125 hz. Your lovely box is good down to much lower. And keep up the 112db. With any horn you trade reproducable bandwidth for efficiency.
Mark
P.S. The 8" driver has been chosen. Creative Sound Solutions Trio 8. It was chosen because it has the highest output at the best base SPL of any affordable 8" driver. Actually that was the same reasoning to use the SDX7. Nothing else even came close. The 4pc SDX7 in a proper horn is coming down the pipes. (Yes Pun intended ) It depends on how many rain days I get this week!
Hi DrpMalone
I don't put to much effort into saying how great things are with this design. A couple of gents tried it out. The one on the left promises to post his thoughts on the matter.
As for some of your comments they are well taken but I would add this little blurb.
You no doubt understand that to our ears a heavily distorted 2 and 3rd harmonic of the original note being played sounds like louder bass. In simpler terms if we have a low b flat from a 6 string bass we are looking at a fundamental of about 32hz. The vast majority of subs cannot really give you that note with out compression or loss of amplitude better described as sound pressure level. So what we hear is the 2nd harmonic 64hz and the third harmonic 128hz. It sounds impressive. But it's not the real low bass you'd hope for. This distortion is unfortunately there in most of the subs that I have worked with and requested by most of the people I do custom work for. You DarpMalone are a man after my own ideal of clean undistorted bass. Just that I have 22watts and not a heck of a lot of space to do it in.
Your system is interesting. I modeled it below and found with cabin gain in most midsized cars your maximum acoustical output is 112db. This is dictated by the diameter of the cone and the throw of the suspension. Not the available power. Once you hit these mechanical limits there is nothing that can be done to make it louder. Except add more drivers. Double the drivers and you get 3db more. You also need double the box.
An externally hosted image should be here but it was not working when we last tested it.
I will humbly point you in the direction of post number 83
We were hitting sustained SPL of 112 and peaks of 114 with less than 15 watts. None of us wanted to go louder we had no hearing protection. The sub could go louder as shown in post # 6
http://www.diyaudio.com/forums/showthread.php?postid=1850643#post1850643
That is the difference between a normal box and even this little poor excuse for a horn. Efficiency. Just think about it two 6.5" drivers match your 10 in a box that is just over 22 liters. A cubic foot is 27 liters! A lot of thinking went into this design.
What this little box cannot do has all ready been presented. Below about 40hz it is out of it's happy space. It's passband is from 38hz to 125 hz. Your lovely box is good down to much lower. And keep up the 112db. With any horn you trade reproducable bandwidth for efficiency.
Mark
P.S. The 8" driver has been chosen. Creative Sound Solutions Trio 8. It was chosen because it has the highest output at the best base SPL of any affordable 8" driver. Actually that was the same reasoning to use the SDX7. Nothing else even came close. The 4pc SDX7 in a proper horn is coming down the pipes. (Yes Pun intended ) It depends on how many rain days I get this week!
Mwm,
I'm interested to know what the cone excursion behavior in this enclosure is like. The inner driver seems to be on a panel with no acoustic structure separating it from the volume of the large internal 'chamber'. I'd imagine that overexcursion would be a problem with this driver (which has a physically separate motor and moving structure from the driver that is in the expanding part of the 'non-horn'. Overexcursion issues may be why this sub objected to having rap music played through it.
I'm interested to know what the cone excursion behavior in this enclosure is like. The inner driver seems to be on a panel with no acoustic structure separating it from the volume of the large internal 'chamber'. I'd imagine that overexcursion would be a problem with this driver (which has a physically separate motor and moving structure from the driver that is in the expanding part of the 'non-horn'. Overexcursion issues may be why this sub objected to having rap music played through it.
Hello Taterworks
The best way to explain it is that I have carefully designed this enclosure to get the maximum available sound level output from two small drivers over a very narrow bandwidth. Outside of that bandwidth like any vented enclosure you get massive cone flap. A horn behaves just like a vented enclosure when driven by a frequency below what the horn was designed for. We have all seen cones flapping madly on vented boxes to. Within it's sweet spot the cones actually are very well behaved. If you had a high pass limiter for the low frequencies you could really drive this sub to crazy levels.
Referencing post Number 6
http://www.diyaudio.com/forums/showthread.php?postid=1850643#post1850643
this is the simulated output that came from Hornresponse
Post # 55
http://www.diyaudio.com/forums/showthread.php?postid=1862219#post1862219
Actual measured response. The bump was a measurement artifact in the car. Tests at a different position gave us minus 1db plus 2 over the same range.
Both drivers are wired so that they pressurize the interior of the horn compression chamber. It produces a more coherent pulse coming out of the horn. This is both simulated and tested in real life. So that means using the driver mounted in the mouth as a start the interior driver is wired with opposite polarity. If it is wired in like polarity there is a null in the output of almost 3db measured at the mouth as it should be in theory. Wired as explained the drivers sum in output and play nice.
The rap music that we were trying had loud fundamentals in the area of 25hz. Adam was the gent who isolated this using a spectrum analyzer on his computer. This horn is not designed to play anything that low. What you get is a very clean sounding small box that will play most popular music to levels that will give you hearing damage in about 15 minutes. I don't know what else you would want other than a competition grade setup. I have designed these. Requests have come in excess of 140db. It can be done but the box requires a trunk donation.
Mark
The best way to explain it is that I have carefully designed this enclosure to get the maximum available sound level output from two small drivers over a very narrow bandwidth. Outside of that bandwidth like any vented enclosure you get massive cone flap. A horn behaves just like a vented enclosure when driven by a frequency below what the horn was designed for. We have all seen cones flapping madly on vented boxes to. Within it's sweet spot the cones actually are very well behaved. If you had a high pass limiter for the low frequencies you could really drive this sub to crazy levels.
Referencing post Number 6
http://www.diyaudio.com/forums/showthread.php?postid=1850643#post1850643
this is the simulated output that came from Hornresponse
Post # 55
http://www.diyaudio.com/forums/showthread.php?postid=1862219#post1862219
Actual measured response. The bump was a measurement artifact in the car. Tests at a different position gave us minus 1db plus 2 over the same range.
Both drivers are wired so that they pressurize the interior of the horn compression chamber. It produces a more coherent pulse coming out of the horn. This is both simulated and tested in real life. So that means using the driver mounted in the mouth as a start the interior driver is wired with opposite polarity. If it is wired in like polarity there is a null in the output of almost 3db measured at the mouth as it should be in theory. Wired as explained the drivers sum in output and play nice.
The rap music that we were trying had loud fundamentals in the area of 25hz. Adam was the gent who isolated this using a spectrum analyzer on his computer. This horn is not designed to play anything that low. What you get is a very clean sounding small box that will play most popular music to levels that will give you hearing damage in about 15 minutes. I don't know what else you would want other than a competition grade setup. I have designed these. Requests have come in excess of 140db. It can be done but the box requires a trunk donation.
Mark
Actually I'm an artist as well (If your interested I can direct you to a place where you can sample my music )... I'm not emotional or sensitive, but I just read your last post and had to reply. Hopefully no one else reading this thread felt that I was assuming you were a moron. Far be it for me to say anything in a public thread that could potentially offend other members of the community or prejudge someone's intelligence, based their musical preferences.
The majority of popular rap music (the stuff that you hear in repetition on the radio and TV all day) is not for me either, but believe me, rap music is an extremely diverse MUSIC and broadly accepted by many of the world's greatest and most highly respected musicians. Like most genres of music, it can be extremely enlightening or it can be plain ignorant. You may not dig them, but perhaps you should check out The Roots, a hip hop band, widely considered to be one of greatest live bands in the world today. They actually play instruments too! It seems that you've only been exposed to pop rap, the same way that the majority of this generation unfortunately will have little or no exposure to classical music because it's not played commercially.
As much as I respect and try to enjoy all music, I also know that apart from acoustic instruments, analog and digitally stynthesized instruments make great music as well and are every bit as valid
I won't attempt to further hi-jack this great thread with a discussion about musical tastes. Anything further from me will be of a constructive nature and relevant to this threads topic.
d
)... I'm not emotional or sensitive, but I just read your last post and had to reply. Hopefully no one else reading this thread felt that I was assuming you were a moron. Far be it for me to say anything in a public thread that could potentially offend other members of the community or prejudge someone's intelligence, based their musical preferences.The majority of popular rap music (the stuff that you hear in repetition on the radio and TV all day) is not for me either, but believe me, rap music is an extremely diverse MUSIC and broadly accepted by many of the world's greatest and most highly respected musicians. Like most genres of music, it can be extremely enlightening or it can be plain ignorant. You may not dig them, but perhaps you should check out The Roots, a hip hop band, widely considered to be one of greatest live bands in the world today. They actually play instruments too! It seems that you've only been exposed to pop rap, the same way that the majority of this generation unfortunately will have little or no exposure to classical music because it's not played commercially.
As much as I respect and try to enjoy all music, I also know that apart from acoustic instruments, analog and digitally stynthesized instruments make great music as well and are every bit as valid
I won't attempt to further hi-jack this great thread with a discussion about musical tastes. Anything further from me will be of a constructive nature and relevant to this threads topic.
d
Hi,
I've read this thread with interest, since I've build a small Tapped Horn as well (for home use, with parametric eq at 40Hz and lowcut), that is maybe suited for car use at moderate SPL, didnt test it in car yet.
The rolloff is dependant on what driver you will use, a wide range of 130mm drivers are possible.
Squirrel-TH
Do you think the rolloff is complimenting the car pressure chamber effect?
-Micha
I've read this thread with interest, since I've build a small Tapped Horn as well (for home use, with parametric eq at 40Hz and lowcut), that is maybe suited for car use at moderate SPL, didnt test it in car yet.
The rolloff is dependant on what driver you will use, a wide range of 130mm drivers are possible.
Squirrel-TH
Do you think the rolloff is complimenting the car pressure chamber effect?
-Micha
Put in the car and.......
It never hurts to try.
You seem to have the means to measure the effects of what you have accomplished so. Put it in the car and check what happens. You will definitely get a boost in the bass response. But you will not get anything more than the horn was designed for. It will just couple more effectively with the smaller air mass in the car and the close boundaries of the car interior.
Mark
It never hurts to try.
You seem to have the means to measure the effects of what you have accomplished so. Put it in the car and check what happens. You will definitely get a boost in the bass response. But you will not get anything more than the horn was designed for. It will just couple more effectively with the smaller air mass in the car and the close boundaries of the car interior.
Mark
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