If you don't like story time scroll down to TLDR for super direct version! 😎
Right off the bat I'd like to say I normally run 600w FTR18-4080F subs since I'm able to source them locally and they have the right power rating to work in my system, I run 4 of these off one mono block 2400w amp in series+parallel configuration, so I need all 4 of them running together in order to get the most power and run properly to get 2400w at 8ohm in series+parallel. I run just my subs with the house system most times for djing since most gigs don't have the low end I need for my music or have muddy overcompressed dead rack units powering their subs so its better for me to bring some bass.
Now I lent a buddy of mine two of my FTR18-4080F subs and he blew them, leaving me with 2 subs and two empty sub slots. He paid me the price of new subs, but I had a djing gig coming up that I needed to use them for and couldn't wait the shipping time on more FTR's.
So I talked to a buddy of mine and he donated me a pair of these 600w rockville RVP18W8's he had as "backup" in case he ever blew a pair of his real 18s at a show, he'd be back up asap.
I asked him if these subs where actually legit if he was giving away for free but he assured me they would be fine, he had tried them and while not as good as his they worked according to him. I took them home, looked them up online and found out they are ultra budget $60 drivers lol so this didn't help my faith very much, I expected to blow them tbh but I was out of options so I tossed them in the gsub cab.
So I ran the show with them cut at 150hz with a low cut at 30hz same as I was running the FTR18-4080F. For this particular show I needed to spread things out a bit so I had two subs on one side and two subs on the other side, due to this I was able to tell the differences between the two subs. Both are nearly equally loud when standing with one on each side of you, but in different ways, the FTR18-4080F was lower/deeper/rumble that felt like higher db at lower hz range while the RVP18W8 seemed to be more poppy/chest hitting higher db at higher hz range. I didn't run any software or anything, this is purely just my opinion from my ears and from standing in front (feel). I think this has to do with the 3 inch verse 4 inch voice coils, only other difference seems to be the FTR has a wider/thinner magnet while the RVP has a thicker/less wide magnet, I'd again assume this is due to voice coil size. The build quality was on par too, I was actually pretty impressed when I unpacked them, this doesnt feel like a cheap off brand like pyle pro ("pyle blows" at rms is more like it) or even a cheap $60 driver, all connections look solid from the voice coil to the posts and even the posts for wire are good (not solder ends or easily removed or broken off pcb). Glue job on the spider and surround are both solid, it even has the wire go into the spider instead of straight to the cone/coil to prevent that dreaded inside cone hitting wire sound like I had on a pair of Dayton Audio subs... So I mean these are getting two thumbs up from me! What I'd like to do is run winisd on both drivers and see the difference instead of standing in front of and poking my head around extremely loud 18s.
Now with that being said, I've used them again since then but right next to each other (side by side, then the RVP cab ontop of the FTR cab) and I think it feels/sounds better then when I had four FTR18-4080F's, the two different sub types even in the same cabs (gsub) produce different volumes of different hz and I honestly like it to the point where I haven't replaced them yet or felt the need to, the RVP is up top and hits your in the chest, the FTR is down bottom and rumbles everything. They pair pretty well together, even power handling, I'm giving them 2400w (their rms) into 4 subs and you can tell they could take more power since there is still a little xmax room in the last ring, but are loud enough/moving enough that I dont feel like I need more power.
With this all being said, the RVP's are in a gsub case made for FTR's, so I'd like to buy another 2 of each and then run 4 of each for a total of 4x double 18x total. Since I already have the FTR cases made, this means designing a case for the RVP's... only problem is I'm either a idiot or their websites specs don't line up with the software I'm using, or both! 😀 I'd like to use winisd again since it worked out great on my FTR gsubs, however again due to being a idiot or their specs, I can't get past putting the speaker specs into the program to even start designing the damn box, or even pick what box type I may want.
Either way I got two new FTR subs on the way now and I want to put them back into their gsubs, so I'll need to do something with these two RVP's since they won't have a case pretty soon here.
TLDR:
~Got donated rockville RVP18W8 $60 subs, extremely surprised I didn't blow them and they kept up to my other 600w subs as advertised.
~Want to make cab for them that actually is made for them since they will be cab-less soon.
~Got their speaker specs put into winisd
~Have set volume and 30hz tune, but aside of port size I'm not sure what I should be changing (that is semi-locked due to wanting to stay at 30hz)
~Only way I can tell to get a wider/flatter response out of it would be to add pEQ and crossover points much like they did with the VBSS (value buster subwoofer system) that ONLY works with dsp programing that is mainly just pEQ settings.
~I understand how to calculate volume into a physical box, minus port volume and how to do the ports when it comes to the physical building aspect. However, not really sure how best to crunch these numbers and/or apply pEQ to see what volume and port size would work best at the 30hz tune I'm aiming for.
Right off the bat I'd like to say I normally run 600w FTR18-4080F subs since I'm able to source them locally and they have the right power rating to work in my system, I run 4 of these off one mono block 2400w amp in series+parallel configuration, so I need all 4 of them running together in order to get the most power and run properly to get 2400w at 8ohm in series+parallel. I run just my subs with the house system most times for djing since most gigs don't have the low end I need for my music or have muddy overcompressed dead rack units powering their subs so its better for me to bring some bass.
Now I lent a buddy of mine two of my FTR18-4080F subs and he blew them, leaving me with 2 subs and two empty sub slots. He paid me the price of new subs, but I had a djing gig coming up that I needed to use them for and couldn't wait the shipping time on more FTR's.
So I talked to a buddy of mine and he donated me a pair of these 600w rockville RVP18W8's he had as "backup" in case he ever blew a pair of his real 18s at a show, he'd be back up asap.
I asked him if these subs where actually legit if he was giving away for free but he assured me they would be fine, he had tried them and while not as good as his they worked according to him. I took them home, looked them up online and found out they are ultra budget $60 drivers lol so this didn't help my faith very much, I expected to blow them tbh but I was out of options so I tossed them in the gsub cab.
So I ran the show with them cut at 150hz with a low cut at 30hz same as I was running the FTR18-4080F. For this particular show I needed to spread things out a bit so I had two subs on one side and two subs on the other side, due to this I was able to tell the differences between the two subs. Both are nearly equally loud when standing with one on each side of you, but in different ways, the FTR18-4080F was lower/deeper/rumble that felt like higher db at lower hz range while the RVP18W8 seemed to be more poppy/chest hitting higher db at higher hz range. I didn't run any software or anything, this is purely just my opinion from my ears and from standing in front (feel). I think this has to do with the 3 inch verse 4 inch voice coils, only other difference seems to be the FTR has a wider/thinner magnet while the RVP has a thicker/less wide magnet, I'd again assume this is due to voice coil size. The build quality was on par too, I was actually pretty impressed when I unpacked them, this doesnt feel like a cheap off brand like pyle pro ("pyle blows" at rms is more like it) or even a cheap $60 driver, all connections look solid from the voice coil to the posts and even the posts for wire are good (not solder ends or easily removed or broken off pcb). Glue job on the spider and surround are both solid, it even has the wire go into the spider instead of straight to the cone/coil to prevent that dreaded inside cone hitting wire sound like I had on a pair of Dayton Audio subs... So I mean these are getting two thumbs up from me! What I'd like to do is run winisd on both drivers and see the difference instead of standing in front of and poking my head around extremely loud 18s.
Now with that being said, I've used them again since then but right next to each other (side by side, then the RVP cab ontop of the FTR cab) and I think it feels/sounds better then when I had four FTR18-4080F's, the two different sub types even in the same cabs (gsub) produce different volumes of different hz and I honestly like it to the point where I haven't replaced them yet or felt the need to, the RVP is up top and hits your in the chest, the FTR is down bottom and rumbles everything. They pair pretty well together, even power handling, I'm giving them 2400w (their rms) into 4 subs and you can tell they could take more power since there is still a little xmax room in the last ring, but are loud enough/moving enough that I dont feel like I need more power.
With this all being said, the RVP's are in a gsub case made for FTR's, so I'd like to buy another 2 of each and then run 4 of each for a total of 4x double 18x total. Since I already have the FTR cases made, this means designing a case for the RVP's... only problem is I'm either a idiot or their websites specs don't line up with the software I'm using, or both! 😀 I'd like to use winisd again since it worked out great on my FTR gsubs, however again due to being a idiot or their specs, I can't get past putting the speaker specs into the program to even start designing the damn box, or even pick what box type I may want.
Either way I got two new FTR subs on the way now and I want to put them back into their gsubs, so I'll need to do something with these two RVP's since they won't have a case pretty soon here.
TLDR:
~Got donated rockville RVP18W8 $60 subs, extremely surprised I didn't blow them and they kept up to my other 600w subs as advertised.
~Want to make cab for them that actually is made for them since they will be cab-less soon.
~Got their speaker specs put into winisd
~Have set volume and 30hz tune, but aside of port size I'm not sure what I should be changing (that is semi-locked due to wanting to stay at 30hz)
~Only way I can tell to get a wider/flatter response out of it would be to add pEQ and crossover points much like they did with the VBSS (value buster subwoofer system) that ONLY works with dsp programing that is mainly just pEQ settings.
~I understand how to calculate volume into a physical box, minus port volume and how to do the ports when it comes to the physical building aspect. However, not really sure how best to crunch these numbers and/or apply pEQ to see what volume and port size would work best at the 30hz tune I'm aiming for.
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Okay heres my issue.
I've put in what matches and I'm left with this list from the speaker specs:
ERM: 0.783
MMD: 125.613 g
KXM: 57.704 m Ohm
EXM: 0.652
And winisd needs these:
le
dd
fle
kle
hc
pe
hg
vd
rms (its showing blue 5.19888 with the data I currently have put in)
xmax
xlim
Someone show me some mercy and help me convert this over or point me in the right direction.
I've put in what matches and I'm left with this list from the speaker specs:
ERM: 0.783
MMD: 125.613 g
KXM: 57.704 m Ohm
EXM: 0.652
And winisd needs these:
le
dd
fle
kle
hc
pe
hg
vd
rms (its showing blue 5.19888 with the data I currently have put in)
xmax
xlim
Someone show me some mercy and help me convert this over or point me in the right direction.
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Actually I'm pretty sure you can't calculate a box with those specs... it doesn't have qts, fs etc. How about you try these what I found from ebay:
REVC: 6.8 Ohm
FO: 31.672 Hz
SD: 1.288 sqCM
BL: 18.769 TM
QMS: 5.826
QES: 0.585
QTS: 0.531
NO: 2.055%
SPLO: 101 dB
VAS: 390.980 Ltr
CMS: 165.907 uM/N
KRM: 9.870 m Ohm
ERM: 0.783
MMS: 152.200 g
MMD: 125.613 g
KXM: 57.704 m Ohm
EXM: 0.652
No need to input all those. Start with Qms, Qes, Fs, Vas.
Oh, Fs seems to be FO in that list
And if you have the automatic calculation on, let the program calculate some values, otherwise it won't work
REVC: 6.8 Ohm
FO: 31.672 Hz
SD: 1.288 sqCM
BL: 18.769 TM
QMS: 5.826
QES: 0.585
QTS: 0.531
NO: 2.055%
SPLO: 101 dB
VAS: 390.980 Ltr
CMS: 165.907 uM/N
KRM: 9.870 m Ohm
ERM: 0.783
MMS: 152.200 g
MMD: 125.613 g
KXM: 57.704 m Ohm
EXM: 0.652
No need to input all those. Start with Qms, Qes, Fs, Vas.
Oh, Fs seems to be FO in that list
And if you have the automatic calculation on, let the program calculate some values, otherwise it won't work
High qts and vas, likes large boxes.
189 liters * 4 boxes gives 126db's from 38hz up. Assuming 5mm xmax just to put a number on it. Also just set LE to 3 as it does not matter that much when making a sub (a high number may help performance a bit). The drivers do like to make a "party hump", as they seem to exibit a bit of a peak from 60-100hz in most semi-compact bass reflex boxes.
189 liters * 4 boxes gives 126db's from 38hz up. Assuming 5mm xmax just to put a number on it. Also just set LE to 3 as it does not matter that much when making a sub (a high number may help performance a bit). The drivers do like to make a "party hump", as they seem to exibit a bit of a peak from 60-100hz in most semi-compact bass reflex boxes.
Those seem to be the same ones from the website?
I reduced it to that list of 4 since those are the 4 I didn't use
ERM: 0.783
KXM: 57.704 m Ohm
EXM: 0.652
Its down to these 3 now since mms and mmd are more or less the same thing but one is with and the other is without the mass of air in the calculation is my loose understanding.
Tbh I'd just like to know wtf these are lol.
If you want full specs from their page:
Code:
Rockville RVP18W8 18" 1200 Watt Raw Replacement Subwoofer
Power RMS: 600 Watts
Peak Power: 1200 Watts
Fiber Reinforced Ultra Stiff Paper Composite Cone
Paper Composite Dust Cap
Expanded and Rolled Steel Basket
Accordion Cloth Surround
Ultra Saturated, High BL Magnetic Motor Gap
3" High Temperature CCAW High SPL Voice Coil
Linear Progressive Conex Spiders
Dual Nickel Plated Banana Plug Terminals
Impedance: 8 Ohms
90 oz Magnet
Mounting Depth: 7.17" inches
Frequency Response: 26 Hz to 500 Hz
Sensitivity: 101dB @ 1w/1m
REVC: 6.8 Ohm
FO: 31.672 Hz
SD: 1.288 sqCM
BL: 18.769 TM
QMS: 5.826
QES: 0.585
QTS: 0.531
NO: 2.055%
SPLO: 101 dB
VAS: 390.980 Ltr
CMS: 165.907 uM/N
KRM: 9.870 m Ohm
ERM: 0.783
MMS: 152.200 g
MMD: 125.613 g
KXM: 57.704 m Ohm
EXM: 0.652Attachments
Seems the issue was with the BL, QTS and SPL.
I put things in, in the order you told me to and BAM it worked.
So I tried filling in the extra things one by one to see what extra information I could add in and I got this far...
Still missing some things tho that I assume would help with the driver but hey at least I can save it now!
I put things in, in the order you told me to and BAM it worked.
So I tried filling in the extra things one by one to see what extra information I could add in and I got this far...
Still missing some things tho that I assume would help with the driver but hey at least I can save it now!
Attachments
Let the program calculate the values, because you have that box checked in the parameter window. See for yourself, first enter Qes and Qms. Then click some other empty field and it should calculate the correct Qts for you, the calculated number comes in blue color. The calculated and inputted value only needs to be off by one decimal and you get that error, that's why it's best to let the program calculate those. Of course it's wise to check the values afterwards.
Haha seems to be working okay now, I feel like I should be trying to calculate the xmax and put that in but.. I'm sitting here crunching numbers 😛
I'm thinking either a vented box or a 4th order bandpass, currently crunching numbers verse both of those.
Open to suggestions or advise 🙂
From what I can tell of these drivers the bandpass is higher spl at lower around 30-40hz but has less spl where the vented isn't going as low but has more spl 40-100hz with a peak at 50-80ish.
I'm thinking either a vented box or a 4th order bandpass, currently crunching numbers verse both of those.
Open to suggestions or advise 🙂
From what I can tell of these drivers the bandpass is higher spl at lower around 30-40hz but has less spl where the vented isn't going as low but has more spl 40-100hz with a peak at 50-80ish.
Thanks for putting in the time to look into these drivers! You rock!
However, I feel bad cuz I don't use hornresp or know what I'm looking at for most of this rockville spec page with your notes. Could you elaborate on FR and SQ or link me to something I could read about them so I can follow what your talking about? Admittedly the bit about TH isnt something I followed either, you obviously know way more about this then I do so thanks for taking the time to reply 🙂
I have been playing around with winisd and you right peq is pretty required to get a flat response out of them or good results.
Looking at your charts tho I like the results your getting with the 2nd option. Thats BR box B? That seems to be around what I'm looking at and trying to get on winisd atm. Also is that with one driver or two?
However, I feel bad cuz I don't use hornresp or know what I'm looking at for most of this rockville spec page with your notes. Could you elaborate on FR and SQ or link me to something I could read about them so I can follow what your talking about? Admittedly the bit about TH isnt something I followed either, you obviously know way more about this then I do so thanks for taking the time to reply 🙂
I have been playing around with winisd and you right peq is pretty required to get a flat response out of them or good results.
Looking at your charts tho I like the results your getting with the 2nd option. Thats BR box B? That seems to be around what I'm looking at and trying to get on winisd atm. Also is that with one driver or two?
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Mello:
That was a box with almost 660 liters internal volume, I think he was just demonstrating the fact that these things like big boxes.
Here is a slightly more "compact" thing with ca 190 liters internal volume.
Do note that since they are more compact, it is difficult to get away from that "party hump", but it could work really nice in a PA setup where one often would boost those frequencies anyway. It does have output to 30hz, which is port resonance, but not a whole lot below 40hz really. Pending on your setup it can work without eq, just filters, depends on implementation.
It will sound "impressive" but not 100% optimal for accurate sound reproduction
To keep it short: Hornresp is better than winisd, but a little bit more complicated, the box numbers are mostly just area/distances/volume, most of it is very basic math, so once you get your brain around, it really is very simple to play around with. If you play around with it you should learn how to use it very fast.
Edit:
Actually, once you know what all the numbers are, winisd can be more cumbersome than hornresp.
That was a box with almost 660 liters internal volume, I think he was just demonstrating the fact that these things like big boxes.
Here is a slightly more "compact" thing with ca 190 liters internal volume.
Do note that since they are more compact, it is difficult to get away from that "party hump", but it could work really nice in a PA setup where one often would boost those frequencies anyway. It does have output to 30hz, which is port resonance, but not a whole lot below 40hz really. Pending on your setup it can work without eq, just filters, depends on implementation.
It will sound "impressive" but not 100% optimal for accurate sound reproduction
To keep it short: Hornresp is better than winisd, but a little bit more complicated, the box numbers are mostly just area/distances/volume, most of it is very basic math, so once you get your brain around, it really is very simple to play around with. If you play around with it you should learn how to use it very fast.
Edit:
Actually, once you know what all the numbers are, winisd can be more cumbersome than hornresp.
Attachments
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Hey sorry for late reply, been super busy!
I think I got most of the ts sorted out so my issue is not really putting in the speaker or the box math of converting volume over to a box case.
My issue is mainly I don't understand what I'm looking for or at on these graph charts, (aside of the db/hz one on winisd, its pretty straight forward, but the rest are not) so its hard to know if what I'm doing is actually being effective or useful towards building a speaker cab. I mean in winisd I can put the driver in, set the volume of the cab and set the hz I want, then play with port sizes but it doesn't seem to change the shape much other then making it go lower and losing db in the party hump or higher in hz and gaining db in the party hump.
So this makes me a bit confused on what I can do to increase volume or get a more flat response out of it to avoid that party hump your talking about.
I have heard of people shaping subs with a dsp like in the case with the value buster subwoofer system to get results that are impossible without it, so I have been playing around with pEQ ect in winisd but again since I have very little experience actually doing this, I got to wonder how much this effects things in the real world and if a flat response line on winisd with pEQ actually translates well into what I want. Cuz I mean I could pEQ plus and minus areas till I get a wider, flatter response on winisd but is that really what I should be doing?
I do have a dsp in my system already, however I use it mainly as a crossover, I don't really use pEQ +/- or anything else... but I'm slowly learning that maybe I should be? Not much I can do about speakers I already have since I can't find TS on them anywhere, but for these rockvilles I could add pEQ if it helped.
I'm not too concerned about the actual building aspect of this, I already have the birch plywood and mdf for a test case and a real case! However I don't want to build something useless by rushing into a design. Its not that I don't want to waste supplies or money, I just feel I won't learn anything if I rush into it and if I don't learn anything then I won't be able to improve the design if its not what I want.
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I don't mind having to buy some more mdf for test cases, but the ultimate goal here is to have a case that works well for EDM, moreso dubstep/dnb growly low ends but it also needs to work for punchy house/techno that will get played on it too.
The only way I'm seeing this as possible currently is by using pEQ and crossover cuts to create a wider, flatter party hump instead of a thiner one that doesn't expand as wide of a hz band. This is the ONLY way the VBSS is possible, is by using pEQ in a dsp. Otherwise the "party hump" makes it look like I'd need to design two different cabs to combine into what I want, thats another idea I'm not completely close minded to either if I had "lower hz party hump" subs on the bottom with "higher hz party hump" subs stacked ontop of them. Or is that a bad idea? And if so: why or why not?
My question tho is again if this is what I should actually be doing? I mean I could add the same pEQ to my dsp in theory, so anything I add in winisd for that should in theory be the same as the dsp, so again in theory it would be better to have a flat speaker that could do both, instead of two cabs that combine to do the same job? Or would it be better to have two cabs, as in, would the two party humps combined be louder/better then using pEQ to force one cab to do both? In theory if you make the party hump wider and flatter you lose max db in the chart, I can only assume since your giving less power to that hz band by playing a wider range, so this makes me wonder again if using pEQ is actually better then creating two different cabs that combined cover the bands I'm looking for.
The only way I'm seeing this as possible currently is by using pEQ and crossover cuts to create a wider, flatter party hump instead of a thiner one that doesn't expand as wide of a hz band. This is the ONLY way the VBSS is possible, is by using pEQ in a dsp. Otherwise the "party hump" makes it look like I'd need to design two different cabs to combine into what I want, thats another idea I'm not completely close minded to either if I had "lower hz party hump" subs on the bottom with "higher hz party hump" subs stacked ontop of them. Or is that a bad idea? And if so: why or why not?
My question tho is again if this is what I should actually be doing? I mean I could add the same pEQ to my dsp in theory, so anything I add in winisd for that should in theory be the same as the dsp, so again in theory it would be better to have a flat speaker that could do both, instead of two cabs that combine to do the same job? Or would it be better to have two cabs, as in, would the two party humps combined be louder/better then using pEQ to force one cab to do both? In theory if you make the party hump wider and flatter you lose max db in the chart, I can only assume since your giving less power to that hz band by playing a wider range, so this makes me wonder again if using pEQ is actually better then creating two different cabs that combined cover the bands I'm looking for.
I mean just quickly tossing the drivers into winisd on a ported cab without pEQ looks okay on the max spl tab.
I'm getting
118db at 30hz
123db at 40hz
126db at 50hz
128db at 60hz to 106hz
0.310 peak cone excursion at 55hz
I'm getting this without pEQ with the following settings:
2x drivers
380L volume
30hz tune freq
1x square vent 3x20 inch, 7.96 deep, two free ends.
system input power 600w
distance 20foot
Now same box with pEQ added:
121db at 30hz
125db at 40hz
129db at 50hz
131db at 60hz to 108hz
0.499 peak cone excursion at 43hz
I've included a picture of the transfer function magnitude from winisd with and without the pEQ added.
From what my uneducated eyes can tell, even this quick, rough job of adding some pEQ flattens out the TFM chart... that seems to also tighten up the db differences between the hz bands I plan to use.
From what I can tell, the limits of this is the peak cone excursion that is heavily effected by pEQ. Problem is I'm not seeing the xmax in their specs and winisd didn't auto fill in the xmax when I put the specs in, I assume its 0.5 from what I can tell so thats what I've tried to stay under.
This is more or less the idea I'm going for, would love some input or corrections.
I'm getting
118db at 30hz
123db at 40hz
126db at 50hz
128db at 60hz to 106hz
0.310 peak cone excursion at 55hz
I'm getting this without pEQ with the following settings:
2x drivers
380L volume
30hz tune freq
1x square vent 3x20 inch, 7.96 deep, two free ends.
system input power 600w
distance 20foot
Now same box with pEQ added:
121db at 30hz
125db at 40hz
129db at 50hz
131db at 60hz to 108hz
0.499 peak cone excursion at 43hz
I've included a picture of the transfer function magnitude from winisd with and without the pEQ added.
From what my uneducated eyes can tell, even this quick, rough job of adding some pEQ flattens out the TFM chart... that seems to also tighten up the db differences between the hz bands I plan to use.
From what I can tell, the limits of this is the peak cone excursion that is heavily effected by pEQ. Problem is I'm not seeing the xmax in their specs and winisd didn't auto fill in the xmax when I put the specs in, I assume its 0.5 from what I can tell so thats what I've tried to stay under.
This is more or less the idea I'm going for, would love some input or corrections.
Attachments
Played around with a different volume 906L (roughly a 2x4x4F box) and got some different results. More flat, less party hump but doesn't go as high on the transfer function magnitute screen, but is for sure more flat and not so much a hump/spike.
Without any pEQ:
127db at 30hz
130db at 40hz
131db at 50hz
131db at 60hz
130db at 127hz
This is interesting to me since on the TFM chart it doesn't go as high as the previous, yet has higher db. It also only 0.39 peak cone excursion verse the 0.5 in the quickie I did above. So this means the sub was working harder in the other case, for less of a pay off from what I can gather, again from uneducated eyes.
The thing I don't get is how tfm translates into db, since the previous build had higher tfm, yet this one has more db.
All I did was:
2x driver
906L (32 square feet)
30hz tune
1x square port 8x26 inch by 9.39 deep.
600w system input power
20f distance
no pEQ
From what I can see of the cone excursion, I could add some pEQ to flatten things off a bit more and boost the area I'd be using most... But if this can do 127-131db at 20feet I'd be more then happy with it since these are going to be used for close range listening ranging from 1 foot to 40 feet away so its not a huge task to have people feel subs within that distance... Am I over thinking this build or am I missing something here?
Without any pEQ:
127db at 30hz
130db at 40hz
131db at 50hz
131db at 60hz
130db at 127hz
This is interesting to me since on the TFM chart it doesn't go as high as the previous, yet has higher db. It also only 0.39 peak cone excursion verse the 0.5 in the quickie I did above. So this means the sub was working harder in the other case, for less of a pay off from what I can gather, again from uneducated eyes.
The thing I don't get is how tfm translates into db, since the previous build had higher tfm, yet this one has more db.
All I did was:
2x driver
906L (32 square feet)
30hz tune
1x square port 8x26 inch by 9.39 deep.
600w system input power
20f distance
no pEQ
From what I can see of the cone excursion, I could add some pEQ to flatten things off a bit more and boost the area I'd be using most... But if this can do 127-131db at 20feet I'd be more then happy with it since these are going to be used for close range listening ranging from 1 foot to 40 feet away so its not a huge task to have people feel subs within that distance... Am I over thinking this build or am I missing something here?
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