http://www.rockfordfosgate.com/rftech/wiringwizard/1_4ohmDVC_2ohm.gif
That Link is to a pic i got at rockford fosgate... is that connected to a single channel or bridged to get that impedence? I have a 15" 4 ohm DVC Sub and a 2 channel 2 ohm stereo stable amp....what is the best way to wire it? Please notify time is of the essence thanks COFFEE HAPPY COFFEE
Replies (29)
Harvester on 12/11/2005 05:13:46
Power Acoustik BL-15 DVC 4ohm Subwoofer
Legacy Blue Diamond LA2080 2400 watt 2 ohm stereo stable amp
ttocs on 12/11/2005 12:33:55
Your amp is stable for 2 ohms as long as it runs a stereo load. If you bridge your amp for 2 ohm mono it will run much hotter, and will have a good chance of melting down.... The only safe way to run the amp with that sub is one channel of the amp to each voice coil. The best way to do it would be if you had a 2nd 15 dvc.
Harvester on 12/11/2005 17:12:34
thanks i appreciate it....the amp runs at 2x200rms does that mean that i am giving the sub 400 watts rms if i hook each coil to its own channel?
compvr15s on 12/12/2005 03:44:05
that is correct, but just be aware, when when wire voice coils seperatly you have to match the voltage to each coil or you will ruin a brand new sub in no time... if they are unevenly matched they will play unevenly, not good... good luck
Harvester on 12/12/2005 03:50:49
What does that mean to match it evenly ....how do you go about doing that?
ttocs on 12/12/2005 11:10:23
this would only be a problem if you were using two different amps, with two different gain adjustments. You will be fine...
Ash on 12/12/2005 21:51:35
That particular setup is quite a mismatch, but it can work if done correctly. The sub is rated at about 350 rms. The amp is overrated so that will be hard to determine without bench testing.
The main problem is a 4 ohm dvc sub will only present a 2 or 8 ohm load unless it is paired with another. This is not a problem if paired with a power matching monoblock, but on a two channel amp that is only stable bridged at 4 ohms, it can be somewhat of a waste.
The option that you may have to resort to is a using the amp into a 8 ohm load briged. The power output will be reduced to about half of the 4 ohm bridged output. The only advantage will be a mono summed output over the stereo setup and lower distortion over the 4 ohm bridged in this setup. You might can get away with running the Legacy amp on the BL-15 in that manner since most recommended enclosures (.707 qtc) are not the highest power handling, unlike (1.1 qtc), sealed that is. 2.0cft is recommended for this sub. If you go with the 3.3cft ported version then you should be alright as well since vented boxes tend to use power more effeciently. Output for that amp in 8 ohm bridged should be around 175-250rms which will be about the same for the sub in a larger enclosure. Input/output should not be a problem since the output will be summed and only one amp gain pot is provided.
Harvester on 12/13/2005 00:15:28
Yeah I have been learning a lot lately... looking at rms instead of peak (what a waste of money). Box types and sizes as well as number of subs....this forum is awesome
Harvester on 12/13/2005 00:18:08
^^^ and current draw..........could some one direct me to the most decent amp for this install?>
compvr15s on 12/13/2005 02:04:58
http://www.sonicelectronix.com/item_1720.html
alpine 350 watt RMS@2ohm class d.
http://www.sonicelectronix.com/item_2747.html
phoenix gold 400 watts RMS@1 to 4ohm class d.
http://www.sonicelectronix.com/item_2853.html
kicker kx400.1 400watts RMS@2omh class d
there are just a couple, 350-400 watts to power your sub at 2omhs, thes will draw 30-40 amps at the most, all are quality manufactures... will match up nicely with that sub, now choosing a quality box design will be ideal to get the most from that sub...
Ash on 12/13/2005 20:09:52
Those are good amps to choose from. They also would deserve a better woofer as well.
The BL-15 should handle about 250 in the 2.0 cft box the manufacturer recommends and should mate decently with the amp in a 8 ohm load bridged. The 2cft will be sealed at Qtc=.89. That will net a robust, warm sounding bass with the slight lift in the 60-80hz range. The -F3 will be about 37hz (quite low) without the car's actual gain. Not a bad combo at all.
I would try running the sub on the amp you have now and see what results you get before scrapping anything. Just simply wire the coils in series, then bridged mono to the amp. Be sure to use some type of dampening material (polyfill, fiberglass insulation, etc) on the inside of the box.
Harvester on 12/15/2005 00:18:39
So I should make a 2 cubic foot sealed box then series the VC's to make an 8 ohm load.....how much polyfill should I use? and should i staple it to the inside on the walls or should I just stuff it with a pound or so? I originally bought this amp with 2 pyramid Hyper Pro Pw1286's and they are 500 rms...i thought 2400 watts would do it....but I didnt know about rms and what it meant and all that but I am learning thank you all
Harvester on 12/15/2005 00:32:24
^^^^^and will the amp draw less current since we are going to 8 ohms?? Damn I wish there were more helpful people like you guys living around here this is awesome
Ash on 12/15/2005 04:15:01
If you are good at woodworking and are familiar with calculating volumes it will be a easy task. Just remember to account for the wood thickness and about an extra .06cft for sub displacement. This way you get a true 2cft for the sub to work in. If you run WIN ISD, it has a pretty good box design program that will give you the exact wood cut measurements.
Stuff the box to about 50-75% of it's volume. Be carefull not to overstuff it. That can actually cause it to "seem" to lose some volume. A 2- 2.75lb loose fill in the general area will work good enough, you only need to worry about stapling when using a ported box or using fiberglass insulation.
Right on! The amp should draw about the same as in a stereo 4 ohm load. I think this setup will be fine and should give you some decent bottom fill. And if you ever decide, you could upgrade to another BL-15 to draw the maximum out of this amp or opt for a 2 ohm stable mono amp.
Good Luck,
Harvester on 12/17/2005 00:55:31
Where can I find Win ISD? The Manual says that the amp draws a maximum of 50 amps and since I have just got the stock alternator in my Nissan I put a bigger battery in it and it seems to hold fine...i think i just have some grounding problems. The music seems to skip when it hits a hard and loud bass note. I am in the process of fixing that right now. I have been to a lot of different forums on the web.....this one is by far the most helpful. I usually got made fun of in the other ones for not knowing much, by people who once had to "start somewhere" too....thanks pplz.
compvr15s on 12/17/2005 04:57:20
grounding is very important, make sure you are using the correct gauge wire, the same size or bigger than you have for power cable, try to keep in under 2 feet but going with the shortest possible is better.
http://www.linearteam.dk/default.aspx?download=winisdpro
just goto start new project and it will go through the steps with ya...
thats why we are proud of our site, there is no need for rude comments or making fun of people, just as you stated everybody started somewhere were wernt born with the knowledge that we now have, i would give CK credit for probably 75% of my knowledge or better... we are here to help people and spread our knowledge onto others so they can inturn help thier friends or refer them to the site... this is very relaxing for most of us, i know i enjoy comming on here every day, and trying to help people out. actually get bummed when i come back and there are no new posts, i will hit reload about every 5-10 mins just waiting to see what people post. and even if i cant help the person im very confident that somebody else can so i will be learning new things too. HAPPY
Harvester on 12/18/2005 11:14:16
ok thanks i am downloading it now
Harvester on 12/18/2005 11:23:42
WINISD
Wow there is a lot of those parameters that i dont know about and that arent available from the power acoustik website....what should I do about them? like the electro mechanical and the large signal and some of the miscellaneous and the advanced parameters(complicated)....here is what i have for it
BL-15
700 watts power handling
350 Watts RMS
85 oz. magnet
2” kapton voice coil
SPL 93 dB
Fs: 22Hz
Vas: 6.05 cu.ft.
Qms: 5.8
Qes: 0.49
Qts: 0.4536
Xmax: 0.3"
Sealed box: 2 cu.Ft
Ported box; 3.3 cu. Ft.
Tuning: 28Hz
Port size: 3” (dia) x 5.8” (length)
# of ports: 1
Harvester on 12/18/2005 11:32:44
Oh it doesnt matter....the program wont even let me save the driver info cause the qts qms and qes parameters failed or something....oh well
Ash on 12/18/2005 16:20:43
You must be doing something wrong for you have more than most manufacturers give.
Once you open the program, click on new in the toolbar. A new smaller window (new project) will pop up.
Click where it says "own drivers" and then click again below that where it says "new".
Enter in the woofer name and the woofer's data being careful that decimals are in the correct place.
Another main thing, if you look to the right of the field that your filling in, make sure that it is the same as the info you have. Example: On Xmax, the BL-15 is given in inches (.3"). Make sure the field is being entered in inches as well unless you have already converted it. If it is reading in "mm" (milimeters) simply click on it until you get the system before entering the data. The same holds for the other fields that have a system reading to the right.
Once all info is entered, look to the bottom of the same window and click ok and it should be saved.
Harvester on 12/18/2005 21:41:20
I read the help file and it says that you shouldnt fill in all of the T/S parameters..I Deleted the first box and it let me save it that time...apparently it wont let you put in wrong information....according to the program the Qes. that the website gave me was 8 thousandths off....anyway ..the program was pretty cool...but i still didnt see box dimensions anywhere
Ash on 12/18/2005 22:56:51
Ok, now that you have it saved....
Again, on the main screen tool bar, click "new". A "new project" (select driver for project) window should pop up as before. Select "own drivers" and scroll down to sub of your choice (BL-15).
Now, click "next" and "driver usage" should already be one. Make sure "placement" is set to "normal". Then click next.
The next screen will be "Box type" and will have a simple drop down menu with closed, vented, and bandpass options. Choose "closed" of course. Click "Finish".
The new screen will now say "{1} closed: BL-15" (or whatever you named it). Right below that in the toolbar click box and then look directly above the sub/box pic and click "box shape".
A new window will open to your left "box shape editor". At the bottom you will see "needed volume(s)" or "Vb.". Enter in the info (2 ft^3) again paying attention to metric or standard before entering.
Now go back up to the top of the same window to "box shape" and choose either one. Enter in your board thickness which is usually .75" (the drop down menu reads thicknesses that are weird so enter in your own). Next click "optimum" and Bamm! You got your measurements in height, width, and depth.
If you don't like the particular shape it gives you then you can change the one you want to what you want and then left click on the dimension that you want to sacrifice the change on and it will automatically come out to the desired airspace.
Play around with things and you will see. Hope this helps.
Harvester on 12/19/2005 00:22:01
actually after the boxtype screen it gives me another drop down menu called Allignment its give me a choice from 0.707 max flat amplitude response to 1.500 equal ripple response...whats all that about?
Harvester on 12/19/2005 00:24:37
I went ahead and selected the 0.707 max flat and followed what you said to the next window and when i click on the box shape icon it says that this feature is not available in the alpha release....must be something new i guess
Harvester on 12/19/2005 00:25:26
and it says that i need a 4.1 cubic foot box.....for a 15????
Harvester on 12/19/2005 01:17:57
Ok i downloaded the beta version and it says that i need 4.2 cubic feet.......that kinda big for a sealed enclosure for this type of sub isnt it?
Harvester on 12/19/2005 01:20:48
Driver : Power Acoustik BL-15
Vas : 6.049
Qts : 0.45
Fs : 22.00
SPL : 93.00
--
Project by : Richard
Project for : you
--
Number of drivers : 1
Box type : Closed
Box size : 4.231 ft^3
Relative
Freq Gain Phase SPL
[Hz] [dB] [deg] [dB]
20.00 -9.88 128.02 83.12
25.00 -6.59 114.01 86.41
30.00 -4.33 100.43 88.67
35.00 -2.84 88.09 90.16
40.00 -1.87 77.43 91.13
45.00 -1.25 68.52 91.75
50.00 -0.86 61.14 92.14
55.00 -0.60 55.05 92.40
60.00 -0.43 49.99 92.57
65.00 -0.31 45.75 92.69
70.00 -0.23 42.15 92.77
75.00 -0.18 39.08 92.82
80.00 -0.14 36.42 92.86
85.00 -0.11 34.10 92.89
90.00 -0.08 32.05 92.92
95.00 -0.07 30.25 92.93
100.00 -0.05 28.63 92.95
--
Generated with WinISD[0.44] freeware (C) Juha Hartikainen
You can download your own copy from : http://www.linearteam.org
Ash on 12/19/2005 06:00:05
It automatically chooses the lowest amplitude. However, this is not always the best.
Maximum power handling with acceptable sound quality for woofers in a sealed format occurs at 1.1 Qtc. As Qtc increases so does F3 (lowest bass note a -3db). Above that, the tonal quality becomes undesirable with a large peak.
Likewise, as the Qtc decreases, so does the peakiness (flat). So does power handling while overall excursion is increased. F3 decreases as well and overall tonal quality goes from robust to shallow with more resonant low bass & low bass extension to a certain point. It must be noted that continuing Qtc. lower than .7 can increase F3. This also is not desirable.
Between the two a happy medium between sound quality & power handling must be found. So as you see the manufacturer chose one in which handling is still good as well as low frequency output (Qtc= .91). Since you are using less power, you might be able to use the larger box, but there is not much to gain from it. That sub already has a low F3 even at higher Qtc's. I would stick to the 2cft and see how it sounds. As far as power, all you need is at least half the maximum rms power handling of a given Qtc to perform. That you should have. You should be fine.
Harvester on 12/19/2005 11:55:06
Cool...I'll stick with the 2cubic foot box....thanks for your help
That Link is to a pic i got at rockford fosgate... is that connected to a single channel or bridged to get that impedence? I have a 15" 4 ohm DVC Sub and a 2 channel 2 ohm stereo stable amp....what is the best way to wire it? Please notify time is of the essence thanks COFFEE HAPPY COFFEE
Replies (29)
Harvester on 12/11/2005 05:13:46
Power Acoustik BL-15 DVC 4ohm Subwoofer
Legacy Blue Diamond LA2080 2400 watt 2 ohm stereo stable amp
ttocs on 12/11/2005 12:33:55
Your amp is stable for 2 ohms as long as it runs a stereo load. If you bridge your amp for 2 ohm mono it will run much hotter, and will have a good chance of melting down.... The only safe way to run the amp with that sub is one channel of the amp to each voice coil. The best way to do it would be if you had a 2nd 15 dvc.
Harvester on 12/11/2005 17:12:34
thanks i appreciate it....the amp runs at 2x200rms does that mean that i am giving the sub 400 watts rms if i hook each coil to its own channel?
compvr15s on 12/12/2005 03:44:05
that is correct, but just be aware, when when wire voice coils seperatly you have to match the voltage to each coil or you will ruin a brand new sub in no time... if they are unevenly matched they will play unevenly, not good... good luck
Harvester on 12/12/2005 03:50:49
What does that mean to match it evenly ....how do you go about doing that?
ttocs on 12/12/2005 11:10:23
this would only be a problem if you were using two different amps, with two different gain adjustments. You will be fine...
Ash on 12/12/2005 21:51:35
That particular setup is quite a mismatch, but it can work if done correctly. The sub is rated at about 350 rms. The amp is overrated so that will be hard to determine without bench testing.
The main problem is a 4 ohm dvc sub will only present a 2 or 8 ohm load unless it is paired with another. This is not a problem if paired with a power matching monoblock, but on a two channel amp that is only stable bridged at 4 ohms, it can be somewhat of a waste.
The option that you may have to resort to is a using the amp into a 8 ohm load briged. The power output will be reduced to about half of the 4 ohm bridged output. The only advantage will be a mono summed output over the stereo setup and lower distortion over the 4 ohm bridged in this setup. You might can get away with running the Legacy amp on the BL-15 in that manner since most recommended enclosures (.707 qtc) are not the highest power handling, unlike (1.1 qtc), sealed that is. 2.0cft is recommended for this sub. If you go with the 3.3cft ported version then you should be alright as well since vented boxes tend to use power more effeciently. Output for that amp in 8 ohm bridged should be around 175-250rms which will be about the same for the sub in a larger enclosure. Input/output should not be a problem since the output will be summed and only one amp gain pot is provided.
Harvester on 12/13/2005 00:15:28
Yeah I have been learning a lot lately... looking at rms instead of peak (what a waste of money). Box types and sizes as well as number of subs....this forum is awesome
Harvester on 12/13/2005 00:18:08
^^^ and current draw..........could some one direct me to the most decent amp for this install?>
compvr15s on 12/13/2005 02:04:58
http://www.sonicelectronix.com/item_1720.html
alpine 350 watt RMS@2ohm class d.
http://www.sonicelectronix.com/item_2747.html
phoenix gold 400 watts RMS@1 to 4ohm class d.
http://www.sonicelectronix.com/item_2853.html
kicker kx400.1 400watts RMS@2omh class d
there are just a couple, 350-400 watts to power your sub at 2omhs, thes will draw 30-40 amps at the most, all are quality manufactures... will match up nicely with that sub, now choosing a quality box design will be ideal to get the most from that sub...
Ash on 12/13/2005 20:09:52
Those are good amps to choose from. They also would deserve a better woofer as well.
The BL-15 should handle about 250 in the 2.0 cft box the manufacturer recommends and should mate decently with the amp in a 8 ohm load bridged. The 2cft will be sealed at Qtc=.89. That will net a robust, warm sounding bass with the slight lift in the 60-80hz range. The -F3 will be about 37hz (quite low) without the car's actual gain. Not a bad combo at all.
I would try running the sub on the amp you have now and see what results you get before scrapping anything. Just simply wire the coils in series, then bridged mono to the amp. Be sure to use some type of dampening material (polyfill, fiberglass insulation, etc) on the inside of the box.
Harvester on 12/15/2005 00:18:39
So I should make a 2 cubic foot sealed box then series the VC's to make an 8 ohm load.....how much polyfill should I use? and should i staple it to the inside on the walls or should I just stuff it with a pound or so? I originally bought this amp with 2 pyramid Hyper Pro Pw1286's and they are 500 rms...i thought 2400 watts would do it....but I didnt know about rms and what it meant and all that but I am learning thank you all
Harvester on 12/15/2005 00:32:24
^^^^^and will the amp draw less current since we are going to 8 ohms?? Damn I wish there were more helpful people like you guys living around here this is awesome
Ash on 12/15/2005 04:15:01
If you are good at woodworking and are familiar with calculating volumes it will be a easy task. Just remember to account for the wood thickness and about an extra .06cft for sub displacement. This way you get a true 2cft for the sub to work in. If you run WIN ISD, it has a pretty good box design program that will give you the exact wood cut measurements.
Stuff the box to about 50-75% of it's volume. Be carefull not to overstuff it. That can actually cause it to "seem" to lose some volume. A 2- 2.75lb loose fill in the general area will work good enough, you only need to worry about stapling when using a ported box or using fiberglass insulation.
Right on! The amp should draw about the same as in a stereo 4 ohm load. I think this setup will be fine and should give you some decent bottom fill. And if you ever decide, you could upgrade to another BL-15 to draw the maximum out of this amp or opt for a 2 ohm stable mono amp.
Good Luck,
Harvester on 12/17/2005 00:55:31
Where can I find Win ISD? The Manual says that the amp draws a maximum of 50 amps and since I have just got the stock alternator in my Nissan I put a bigger battery in it and it seems to hold fine...i think i just have some grounding problems. The music seems to skip when it hits a hard and loud bass note. I am in the process of fixing that right now. I have been to a lot of different forums on the web.....this one is by far the most helpful. I usually got made fun of in the other ones for not knowing much, by people who once had to "start somewhere" too....thanks pplz.
compvr15s on 12/17/2005 04:57:20
grounding is very important, make sure you are using the correct gauge wire, the same size or bigger than you have for power cable, try to keep in under 2 feet but going with the shortest possible is better.
http://www.linearteam.dk/default.aspx?download=winisdpro
just goto start new project and it will go through the steps with ya...
thats why we are proud of our site, there is no need for rude comments or making fun of people, just as you stated everybody started somewhere were wernt born with the knowledge that we now have, i would give CK credit for probably 75% of my knowledge or better... we are here to help people and spread our knowledge onto others so they can inturn help thier friends or refer them to the site... this is very relaxing for most of us, i know i enjoy comming on here every day, and trying to help people out. actually get bummed when i come back and there are no new posts, i will hit reload about every 5-10 mins just waiting to see what people post. and even if i cant help the person im very confident that somebody else can so i will be learning new things too. HAPPY
Harvester on 12/18/2005 11:14:16
ok thanks i am downloading it now
Harvester on 12/18/2005 11:23:42
WINISD
Wow there is a lot of those parameters that i dont know about and that arent available from the power acoustik website....what should I do about them? like the electro mechanical and the large signal and some of the miscellaneous and the advanced parameters(complicated)....here is what i have for it
BL-15
700 watts power handling
350 Watts RMS
85 oz. magnet
2” kapton voice coil
SPL 93 dB
Fs: 22Hz
Vas: 6.05 cu.ft.
Qms: 5.8
Qes: 0.49
Qts: 0.4536
Xmax: 0.3"
Sealed box: 2 cu.Ft
Ported box; 3.3 cu. Ft.
Tuning: 28Hz
Port size: 3” (dia) x 5.8” (length)
# of ports: 1
Harvester on 12/18/2005 11:32:44
Oh it doesnt matter....the program wont even let me save the driver info cause the qts qms and qes parameters failed or something....oh well
Ash on 12/18/2005 16:20:43
You must be doing something wrong for you have more than most manufacturers give.
Once you open the program, click on new in the toolbar. A new smaller window (new project) will pop up.
Click where it says "own drivers" and then click again below that where it says "new".
Enter in the woofer name and the woofer's data being careful that decimals are in the correct place.
Another main thing, if you look to the right of the field that your filling in, make sure that it is the same as the info you have. Example: On Xmax, the BL-15 is given in inches (.3"). Make sure the field is being entered in inches as well unless you have already converted it. If it is reading in "mm" (milimeters) simply click on it until you get the system before entering the data. The same holds for the other fields that have a system reading to the right.
Once all info is entered, look to the bottom of the same window and click ok and it should be saved.
Harvester on 12/18/2005 21:41:20
I read the help file and it says that you shouldnt fill in all of the T/S parameters..I Deleted the first box and it let me save it that time...apparently it wont let you put in wrong information....according to the program the Qes. that the website gave me was 8 thousandths off....anyway ..the program was pretty cool...but i still didnt see box dimensions anywhere
Ash on 12/18/2005 22:56:51
Ok, now that you have it saved....
Again, on the main screen tool bar, click "new". A "new project" (select driver for project) window should pop up as before. Select "own drivers" and scroll down to sub of your choice (BL-15).
Now, click "next" and "driver usage" should already be one. Make sure "placement" is set to "normal". Then click next.
The next screen will be "Box type" and will have a simple drop down menu with closed, vented, and bandpass options. Choose "closed" of course. Click "Finish".
The new screen will now say "{1} closed: BL-15" (or whatever you named it). Right below that in the toolbar click box and then look directly above the sub/box pic and click "box shape".
A new window will open to your left "box shape editor". At the bottom you will see "needed volume(s)" or "Vb.". Enter in the info (2 ft^3) again paying attention to metric or standard before entering.
Now go back up to the top of the same window to "box shape" and choose either one. Enter in your board thickness which is usually .75" (the drop down menu reads thicknesses that are weird so enter in your own). Next click "optimum" and Bamm! You got your measurements in height, width, and depth.
If you don't like the particular shape it gives you then you can change the one you want to what you want and then left click on the dimension that you want to sacrifice the change on and it will automatically come out to the desired airspace.
Play around with things and you will see. Hope this helps.
Harvester on 12/19/2005 00:22:01
actually after the boxtype screen it gives me another drop down menu called Allignment its give me a choice from 0.707 max flat amplitude response to 1.500 equal ripple response...whats all that about?
Harvester on 12/19/2005 00:24:37
I went ahead and selected the 0.707 max flat and followed what you said to the next window and when i click on the box shape icon it says that this feature is not available in the alpha release....must be something new i guess
Harvester on 12/19/2005 00:25:26
and it says that i need a 4.1 cubic foot box.....for a 15????
Harvester on 12/19/2005 01:17:57
Ok i downloaded the beta version and it says that i need 4.2 cubic feet.......that kinda big for a sealed enclosure for this type of sub isnt it?
Harvester on 12/19/2005 01:20:48
Driver : Power Acoustik BL-15
Vas : 6.049
Qts : 0.45
Fs : 22.00
SPL : 93.00
--
Project by : Richard
Project for : you
--
Number of drivers : 1
Box type : Closed
Box size : 4.231 ft^3
Relative
Freq Gain Phase SPL
[Hz] [dB] [deg] [dB]
20.00 -9.88 128.02 83.12
25.00 -6.59 114.01 86.41
30.00 -4.33 100.43 88.67
35.00 -2.84 88.09 90.16
40.00 -1.87 77.43 91.13
45.00 -1.25 68.52 91.75
50.00 -0.86 61.14 92.14
55.00 -0.60 55.05 92.40
60.00 -0.43 49.99 92.57
65.00 -0.31 45.75 92.69
70.00 -0.23 42.15 92.77
75.00 -0.18 39.08 92.82
80.00 -0.14 36.42 92.86
85.00 -0.11 34.10 92.89
90.00 -0.08 32.05 92.92
95.00 -0.07 30.25 92.93
100.00 -0.05 28.63 92.95
--
Generated with WinISD[0.44] freeware (C) Juha Hartikainen
You can download your own copy from : http://www.linearteam.org
Ash on 12/19/2005 06:00:05
It automatically chooses the lowest amplitude. However, this is not always the best.
Maximum power handling with acceptable sound quality for woofers in a sealed format occurs at 1.1 Qtc. As Qtc increases so does F3 (lowest bass note a -3db). Above that, the tonal quality becomes undesirable with a large peak.
Likewise, as the Qtc decreases, so does the peakiness (flat). So does power handling while overall excursion is increased. F3 decreases as well and overall tonal quality goes from robust to shallow with more resonant low bass & low bass extension to a certain point. It must be noted that continuing Qtc. lower than .7 can increase F3. This also is not desirable.
Between the two a happy medium between sound quality & power handling must be found. So as you see the manufacturer chose one in which handling is still good as well as low frequency output (Qtc= .91). Since you are using less power, you might be able to use the larger box, but there is not much to gain from it. That sub already has a low F3 even at higher Qtc's. I would stick to the 2cft and see how it sounds. As far as power, all you need is at least half the maximum rms power handling of a given Qtc to perform. That you should have. You should be fine.
Harvester on 12/19/2005 11:55:06
Cool...I'll stick with the 2cubic foot box....thanks for your help
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