hello friends
I Carlos From Colombia, i already buy almost 6 months a DB II from DECWARE, that is playing in my Susuky Twin Cam car, with a cheap 10 " DVC subwoofer, thats sound Good but now I like to make a new Box. Myabe a Dual chamber Box or a TL box.
Someone tell me that i have to do it this way :
" The first (larger) chamber is twice as large as the second side and all ports are the exact same size. They have two tuning frequencies and get very loud at all frequencies between the two. when designing them, design them as one large box with 2 ports, then split them 2/3 and 1/3. when building, remember to account for port and sub displacement. The bigger the box, the louder it will get, but mechanical power handling may be impaired (similar to a large ported box). "
I have a few Questions :
What it mean "but mechanical power handling may be impaired " ???
Do i have to use stuff in both chambers ??
Does this box sound better than a TL Box. ??
Here you can see the diagram of the Box Is somone car page NOT Mine. So I give all the credits to him.
http://www.sounddomain.com/member_pages/view_page.pl?page_id=318757&page=2
Sorry for my english ....
AND THANKS
CARLOS GARCIA
Final question How can I insert a image form my computer
I Carlos From Colombia, i already buy almost 6 months a DB II from DECWARE, that is playing in my Susuky Twin Cam car, with a cheap 10 " DVC subwoofer, thats sound Good but now I like to make a new Box. Myabe a Dual chamber Box or a TL box.
Someone tell me that i have to do it this way :
" The first (larger) chamber is twice as large as the second side and all ports are the exact same size. They have two tuning frequencies and get very loud at all frequencies between the two. when designing them, design them as one large box with 2 ports, then split them 2/3 and 1/3. when building, remember to account for port and sub displacement. The bigger the box, the louder it will get, but mechanical power handling may be impaired (similar to a large ported box). "
I have a few Questions :
What it mean "but mechanical power handling may be impaired " ???
Do i have to use stuff in both chambers ??
Does this box sound better than a TL Box. ??
Here you can see the diagram of the Box Is somone car page NOT Mine. So I give all the credits to him.
http://www.sounddomain.com/member_pages/view_page.pl?page_id=318757&page=2
Sorry for my english ....
AND THANKS
CARLOS GARCIA
Final question How can I insert a image form my computer
Hello,
try reading those : http://www.diysubwoofers.org/prt/dual_chamber.htm
http://www.diyaudio.com/forums/showthread.php?threadid=3699&highlight=double+chamber+reflex+Weems
Regards
Claudio
try reading those : http://www.diysubwoofers.org/prt/dual_chamber.htm
http://www.diyaudio.com/forums/showthread.php?threadid=3699&highlight=double+chamber+reflex+Weems
Regards
Claudio
KELT and Claudio
I show you my speaker Box plot in WINISD, i calculate the vents the way you explain in the past post.
Driver : PIONEER TSW 304 F 12"
Project by : Carlos
Project for : you
--
Number of drivers : 1
Box type : Vented
Box size : 125,3 l
Tuning frequency : 28,82 Hz
Vent : 2 vent(s)
3,05 in length for each
2,00 in round
Relative
Freq Gain SPL
[Hz] [dB] [dB]
20,00 -12,60 -12,60
25,00 -4,90 -4,90
30,00 -1,24 -1,24
35,00 -0,29 -0,29
40,00 -0,10 -0,10
45,00 -0,06 -0,06
50,00 -0,04 -0,04
55,00 -0,03 -0,03
60,00 -0,02 -0,02
65,00 -0,01 -0,01
70,00 -0,01 -0,01
75,00 0,00 0,00
80,00 0,00 0,00
85,00 0,00 0,00
90,00 0,00 0,00
95,00 0,00 0,00
100,00 0,00 0,00
I show you my speaker Box plot in WINISD, i calculate the vents the way you explain in the past post.
Driver : PIONEER TSW 304 F 12"
Project by : Carlos
Project for : you
--
Number of drivers : 1
Box type : Vented
Box size : 125,3 l
Tuning frequency : 28,82 Hz
Vent : 2 vent(s)
3,05 in length for each
2,00 in round
Relative
Freq Gain SPL
[Hz] [dB] [dB]
20,00 -12,60 -12,60
25,00 -4,90 -4,90
30,00 -1,24 -1,24
35,00 -0,29 -0,29
40,00 -0,10 -0,10
45,00 -0,06 -0,06
50,00 -0,04 -0,04
55,00 -0,03 -0,03
60,00 -0,02 -0,02
65,00 -0,01 -0,01
70,00 -0,01 -0,01
75,00 0,00 0,00
80,00 0,00 0,00
85,00 0,00 0,00
90,00 0,00 0,00
95,00 0,00 0,00
100,00 0,00 0,00
Hi Kelticwizard,
here's a pic but I have stopped the testing cause I was working on my home page, that speaks about Speaker Workshop and double chamber reflex.
Suministros, the ports looks right, but Iwould use a larger diameter since it's a 10 inch woofer.
However I am not familiar with car speakers, maybe someone else could help you. Maybe a closed box would prevent too bumpy lows.
here's a pic but I have stopped the testing cause I was working on my home page, that speaks about Speaker Workshop and double chamber reflex.
Suministros, the ports looks right, but Iwould use a larger diameter since it's a 10 inch woofer.
However I am not familiar with car speakers, maybe someone else could help you. Maybe a closed box would prevent too bumpy lows.
Attachments
Claudio:
Well, the double chamber reflex boxes you made are certainly stylish. Nice job.
The double chamber reflex design is an excellent choice if you are going to use a two way design that still gives out deep bass. The more the cone has to move at bass frequencies, the more the midrange gets muddied. This is called Intermodulation Distortion and it is audible as the "fuzz" an overdriven speaker gives.
A closed box speaker gives no excursion relief at bass frequencies, and therefore the midrange frequencies get muddied. The conventional single chamber reflex, (ported) gives substantial excursion relief, (ie, the cone must move much less to produce the same bass output as the Closed Box). This excursion relief is given through the lowest octave of the speaker's range-where the speaker will be moving the most.
The double chamber reflex extends this relief upward another octave, making the midrange even less distorted than the single chamber reflex, which itself was quite an improvement over the Closed Box in this respect!
It is sort of a tradeoff. The port adds a certain degree of distortion over the closed box at bass frequencies, but it cuts down on the cone excursion that muddies the mid and high frequencies.
Having never heard a double chamber reflex, I would speculate that the tradeoffs favor the double chamber design. That is because the ear is less sensitive to distortions at the bass frequencies than it is at the midrange frequencies. Therefore, you are better off keeping the midrange frequencies-where most of the music is-as clear as possible.
If you have to have higher distortion in some range as compensation, make it the bass range. That is what the double chamber design does.
Of course, it would be a good idea for me to listen to one to verify this theory. But if I had to speculate, that would be my guess.
Are those yellow coned drivers Focals? And what brand of ribbon tweeter are you using?
Well, the double chamber reflex boxes you made are certainly stylish. Nice job.
The double chamber reflex design is an excellent choice if you are going to use a two way design that still gives out deep bass. The more the cone has to move at bass frequencies, the more the midrange gets muddied. This is called Intermodulation Distortion and it is audible as the "fuzz" an overdriven speaker gives.
A closed box speaker gives no excursion relief at bass frequencies, and therefore the midrange frequencies get muddied. The conventional single chamber reflex, (ported) gives substantial excursion relief, (ie, the cone must move much less to produce the same bass output as the Closed Box). This excursion relief is given through the lowest octave of the speaker's range-where the speaker will be moving the most.
The double chamber reflex extends this relief upward another octave, making the midrange even less distorted than the single chamber reflex, which itself was quite an improvement over the Closed Box in this respect!
It is sort of a tradeoff. The port adds a certain degree of distortion over the closed box at bass frequencies, but it cuts down on the cone excursion that muddies the mid and high frequencies.
Having never heard a double chamber reflex, I would speculate that the tradeoffs favor the double chamber design. That is because the ear is less sensitive to distortions at the bass frequencies than it is at the midrange frequencies. Therefore, you are better off keeping the midrange frequencies-where most of the music is-as clear as possible.
If you have to have higher distortion in some range as compensation, make it the bass range. That is what the double chamber design does.
Of course, it would be a good idea for me to listen to one to verify this theory
. But if I had to speculate, that would be my guess.Are those yellow coned drivers Focals? And what brand of ribbon tweeter are you using?
bandpass
yes
if you model the port to be large area,it wont puff and have lower compression <17m/s
Personaly i think all too often we hear boomy bandpass boxes
-car audio has to answer for that
a box designed to notboom- will surely sound better..there was an article in EA that has a bandpass box so an optimized one with ideal woofer should be fine
il stick to my sealed or ported boxes :-D
1% distortion isnt so bad in the bass range-its hard to find exact numbers.also IM distortion sounds more disgusting than normal harmonic related distortion
1% distortion in the midrange would be awful
yes
if you model the port to be large area,it wont puff and have lower compression <17m/s
Personaly i think all too often we hear boomy bandpass boxes
-car audio has to answer for that
a box designed to notboom- will surely sound better..there was an article in EA that has a bandpass box so an optimized one with ideal woofer should be fine
il stick to my sealed or ported boxes :-D
1% distortion isnt so bad in the bass range-its hard to find exact numbers.also IM distortion sounds more disgusting than normal harmonic related distortion
1% distortion in the midrange would be awful
Mikee:
I don't know that the bass is really any smoother in a Double Chamber Reflex than in a conventional reflex, (ported). In fact, I have read that there is some small interference between the ports that might make the bass of the Double Chamber reflex slightly worse. Whether this is audible, I do not know.
But the big benefit of the Double Chamber Reflex is that it cuts down even more on the Intermodulation Distortion in the midrange. And as you pointed out, distortion up there is much more audible than distortion in the bass.
It is all well and good to take distortion measurements at 1 Watt. But if your woofer is going to carry both the bass and midrange, what do you think is happening to the delicate female voices while the woofer that carries them is going back and forth 1/8" or more, in order to produce the bass frequencies even at moderate power levels? Not pretty. After all, bass requires a lot of air to be moved-the midrnge frequencies significantly less so.
The more the cone must move to produce bass, the more the midrange suffers from Intermodulation Distortion. There is no way around that, assuming the bass driver is carrying the midrange.
I would go so far as to say that building a two way Double Chamber Reflex is akin to building a three way speaker with the bass driver of the 3 way crossing over two octaves above the port frequency. In other words, a 3 way with crossovers at 160 Hz and 2500 Hz is equivalent to a Double Chamber Reflex with a crossover of 2500 Hz. The only differences, I would think, would be slightly more distortion in the 40 Hz to 60 Hz range and less dispersion in the midrange, since the 3 way is likely to use a midrange driver smaller in diameter than the bass driver.
Again, I have neither heard nor measured the Double Chamber Reflex. However, the formulas for excursion/IM distortion would indicate that is how it works.
I don't know that the bass is really any smoother in a Double Chamber Reflex than in a conventional reflex, (ported). In fact, I have read that there is some small interference between the ports that might make the bass of the Double Chamber reflex slightly worse. Whether this is audible, I do not know.
But the big benefit of the Double Chamber Reflex is that it cuts down even more on the Intermodulation Distortion in the midrange. And as you pointed out, distortion up there is much more audible than distortion in the bass.
It is all well and good to take distortion measurements at 1 Watt. But if your woofer is going to carry both the bass and midrange, what do you think is happening to the delicate female voices while the woofer that carries them is going back and forth 1/8" or more, in order to produce the bass frequencies even at moderate power levels? Not pretty. After all, bass requires a lot of air to be moved-the midrnge frequencies significantly less so.
The more the cone must move to produce bass, the more the midrange suffers from Intermodulation Distortion. There is no way around that, assuming the bass driver is carrying the midrange.
I would go so far as to say that building a two way Double Chamber Reflex is akin to building a three way speaker with the bass driver of the 3 way crossing over two octaves above the port frequency. In other words, a 3 way with crossovers at 160 Hz and 2500 Hz is equivalent to a Double Chamber Reflex with a crossover of 2500 Hz. The only differences, I would think, would be slightly more distortion in the 40 Hz to 60 Hz range and less dispersion in the midrange, since the 3 way is likely to use a midrange driver smaller in diameter than the bass driver.
Again, I have neither heard nor measured the Double Chamber Reflex. However, the formulas for excursion/IM distortion would indicate that is how it works.
Re: bandpass+distortion
Is that 1% figure for Harmonic Distortion or Intermodulation distortion? I would guess the only way to measure Intermodulation Distortion would be the way Paul Klipsch did-running two or more specific tones through a speaker and see the how large the distortion frequencies are. That test is rarely performed.
And why do basshorns sound so exquisite even though the reflex has a deeper cutoff per cubic foot of enclosure? Because the horn suppresses cone excursion even more than the reflex enclosure does. I love the sound of basshorns, even with their higher cutoffs.
bass horns
mikee12345 said:
yep my jbl is measured at 60watts in ten cubic foot sealed -<1%
probably my amp wil be about 0.5% anywys at moderate power-but i must try a bandpass sometime because they are different
Is that 1% figure for Harmonic Distortion or Intermodulation distortion? I would guess the only way to measure Intermodulation Distortion would be the way Paul Klipsch did-running two or more specific tones through a speaker and see the how large the distortion frequencies are. That test is rarely performed.
And why do basshorns sound so exquisite even though the reflex has a deeper cutoff per cubic foot of enclosure? Because the horn suppresses cone excursion even more than the reflex enclosure does. I love the sound of basshorns, even with their higher cutoffs.
bass horns
Thanks, Jack. I have been interested in Dalines for some time.
Here is another thread that deals with Dalines. The subject was discussed from Post # 19 on.
http://www.diyaudio.com/forums/showthread.php?threadid=8554&perpage=15&highlight=daline&pagenumber=2
Here is another thread that deals with Dalines. The subject was discussed from Post # 19 on.
http://www.diyaudio.com/forums/showthread.php?threadid=8554&perpage=15&highlight=daline&pagenumber=2
Kelticwizard:
I am using a Focal 7k4412 and a ATD 135 ribbon tweeter.
The cabinet is unfinished cause my intentions are to test it in ported way, then DCR, then try with the tweeter mounted on the top of the box in phase with the woofer( I already made a different front panel to switch with the one you see in the pic).
It's a lot of work and a lot of time, and till now they are just playing with no damping in opposed phase: imagine the sound!
What I believe DCR helps a lot is in diminishing standing waves in tall tower cabinet, like mine. Some impedence measures will tell me if it is the right way to go.
Claudio
I am using a Focal 7k4412 and a ATD 135 ribbon tweeter.
The cabinet is unfinished cause my intentions are to test it in ported way, then DCR, then try with the tweeter mounted on the top of the box in phase with the woofer( I already made a different front panel to switch with the one you see in the pic).
It's a lot of work and a lot of time, and till now they are just playing with no damping in opposed phase: imagine the sound!
What I believe DCR helps a lot is in diminishing standing waves in tall tower cabinet, like mine. Some impedence measures will tell me if it is the right way to go.
Claudio
can you give me Pioneer TSW304 T/S parameter ! please ! I need it !I show you my speaker Box plot in WINISD, i calculate the vents the way you explain in the past post.
Driver : PIONEER TSW 304 F 12"
Project by : Carlos
Project for : you
--
Number of drivers : 1
Box type : Vented
Box size : 125,3 l
Tuning frequency : 28,82 Hz
Vent : 2 vent(s)
3,05 in length for each
2,00 in round
Relative
Freq Gain SPL
[Hz] [dB] [dB]
20,00 -12,60 -12,60
25,00 -4,90 -4,90
30,00 -1,24 -1,24
35,00 -0,29 -0,29
40,00 -0,10 -0,10
45,00 -0,06 -0,06
50,00 -0,04 -0,04
55,00 -0,03 -0,03
60,00 -0,02 -0,02
65,00 -0,01 -0,01
70,00 -0,01 -0,01
75,00 0,00 0,00
80,00 0,00 0,00
85,00 0,00 0,00
90,00 0,00 0,00
95,00 0,00 0,00
100,00 0,00 0,00
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