I am running one of the 823D's off of a JL Audio HD900/5 ... so it is getting up to 500 watts. It is installed in a 2007 Ford Sport Trac in the factory sealed enclosure at .5ft³. When I get it at the highest volume I think it should sound about right, I seem to continuously bottom it out. If I turn it down any lower, it just ain't enough. I am wondering if I knocked that factory enclosure down to about .3ft³ if that would help with the power handling capabilities.
Thanks!
YES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Thats exactly the problem your having ......to large an enclosure!
I am running one of the 823D's off of a JL Audio HD900/5 ... so it is getting up to 500 watts. It is installed in a 2007 Ford Sport Trac in the factory sealed enclosure at .5ft³. When I get it at the highest volume I think it should sound about right, I seem to continuously bottom it out. If I turn it down any lower, it just ain't enough. I am wondering if I knocked that factory enclosure down to about .3ft³ if that would help with the power handling capabilities.
Thanks!
Modelled it and you are going over Xmax @ 57Hz with a 0.5cuft box with 500 watts. Your sub needs half your box in order to take all of the 500 watts yet still keep Xmax below 14mm over the whole bandwith - aka 0.25cuft
Kelvin
Lycan
Quote:
I'll repeat it for the miliionth time : All amps do NOT sound the same ... It's astonishing to me that nobody understands this
I am running one of the 823D's off of a JL Audio HD900/5 ... so it is getting up to 500 watts. It is installed in a 2007 Ford Sport Trac in the factory sealed enclosure at .5ft³. When I get it at the highest volume I think it should sound about right, I seem to continuously bottom it out. If I turn it down any lower, it just ain't enough. I am wondering if I knocked that factory enclosure down to about .3ft³ if that would help with the power handling capabilities.
Thanks!
The smaller enclosure will help prevent that from happening (.35' seems to be the sweet spot sealed) but based on what I've read, 500w is about the upper limit for continous use.
Anyone model a bandpass box for these and is willing to share dimensions? I'm thinking of replacing my Morel Ultimo 12 with 2 of these in a bandpass config with a round vent going through the rear deck.
Anyone model a bandpass box for these and is willing to share dimensions? I'm thinking of replacing my Morel Ultimo 12 with 2 of these in a bandpass config with a round vent going through the rear deck.
X2!!!!!! Not sure how well they will model (probably well considering they do great in everything else and appear to be INSANELY versatile) I think a well designed bandpass box would be sick (again, done properly and in a situation like your after it would be great!)
If it was small enough I would consider it for home or jeep?
Anyone model a bandpass box for these and is willing to share dimensions? I'm thinking of replacing my Morel Ultimo 12 with 2 of these in a bandpass config with a round vent going through the rear deck.
Ok... I modelled the 2 x 8s VS the sealed 12".
SPL wise: YELLOW is Morel 12" in a 1.83cuft sealed box fed with 1000 watts - models strangely with overexcursion @ 60Hz anyway I kept it like so... ORANGE is 2x8s in a 2cuft vented box tuned to 29Hz fed with 750 watts - Subsonic set to 30Hz 12dB/oct slope PINK is 2x8s in a 1.8cuft rear chamber & 1cuft front chamber tuned to 50Hz (4th order bandpass) fed with 500 watts - Subsonic set to 25Hz 12dB/oct slope RED is 2x8s in a 1.5cuft rear chamber tuned to 24Hz & 1.05cuft front chamber tuned to 57Hz (6th order bandpass) also fed with 500 watts.
As you can see, the 6th order seems like the best choice... But there's a "hick" - the port for the rear chamber needs to be an external one:
57.33" long if you use a 5" round port - smaller and you might experience port noise...
How did I get those enclosure sizes and tuning? I went back and forth between the group delay and Xmax tab:
Please note a couple of things... I do believe that group delay is what makes 1 sealed box sound quotation marks "better" unquote marks than let's say a vented enclosure.
Therefore I tried my best to have a smooth group delay in most of the passband for the 4th and 6th order bandpass - not possible to smooth out the group delay with the vented enclosure...
I was chocked at how flat the group delay was for the 4th order bandpass - too bad it's low end is limited due to Xmax similar to the vented enclosure - please note how the SPL is the same @ 20Hz for both enclosures...
IMO, if you can create an external port, I would go with the 6th order bandpass.
Now, it's probably not the best alignments for each box type but I like it like that
Kelvin
Lycan
Quote:
I'll repeat it for the miliionth time : All amps do NOT sound the same ... It's astonishing to me that nobody understands this
WOW! Thank you so much for the hard work subwoofery.
I'm surprised at 2 things; the length of the ports in the bandpass configs and the size of the sealed enclosure for the Morel. I'm running it in a 1.6 cu gross sealed right now fed by an ARC 2300SE in mono (~1300 W).
Sadly, there is no room in my Camaro for a 25" port needed to implement the 4th order config. Since the box is 1 cu that means that more than half the port will be outside and there is simply no room inside the trunk between the floor and the rear deck
Oh well...back to the drawing board. Maybe 3 of these in a sealed enclosure
Yes, Thank you Kelvin!!! I could actually pull that 6th order off in my jeep......allow me to explain! Although I can think of about 1000 options that would make a lot more sense
I have been debating (since I have ZERO plans of putting in my back seat) a shallow box that runs the full size of the rear area of the jeep. Think of a false floor of sorts...being so shallow and with bracing etc.... I can really stretch out a 1cuft box and the great part about it is that I would never have to worry about the subs being exposed to shit tossed in the back of it? The greatest part about it is the WOW factor of course!
Wonder how the ppi art 8s would model in the same situation.... Being that output is there biggest downfall (IMO) but sound amazing, and dont need/take any significant power it could be an interesting scenerio? I will put some more thought into this..... Very COOL!
Thanks again!
Yes, Thank you Kelvin!!! I could actually pull that 6th order off in my jeep......allow me to explain! Although I can think of about 1000 options that would make a lot more sense
I have been debating (since I have ZERO plans of putting in my back seat) a shallow box that runs the full size of the rear area of the jeep. Think of a false floor of sorts...being so shallow and with bracing etc.... I can really stretch out a 1cuft box and the great part about it is that I would never have to worry about the subs being exposed to shit tossed in the back of it? The greatest part about it is the WOW factor of course!
Wonder how the ppi art 8s would model in the same situation.... Being that output is there biggest downfall (IMO) but sound amazing, and dont need/take any significant power it could be an interesting scenerio? I will put some more thought into this..... Very COOL!
Thanks again!
Tried the A.8SQ and it doesn't work in 4th or 6th order bandpass... It wants 0.1cuft on the rear and 0.1cuft on the front - tuned low like 20Hz...
Kelvin
Lycan
Quote:
I'll repeat it for the miliionth time : All amps do NOT sound the same ... It's astonishing to me that nobody understands this
Anyone model a bandpass box for these and is willing to share dimensions? I'm thinking of replacing my Morel Ultimo 12 with 2 of these in a bandpass config with a round vent going through the rear deck.
Bandpass boxes are pretty tough to implement when a woofer has a low VAS and a lot of excursion. That's because the port gets BIGGER as the VAS gets smaller! So all of that hard work that you've invested in reducing the box size is offset by the port!
Making things even more difficult, a sub with a lot of xmax needs a really huge port, in order to move all that air.
This is one of the problems with WinISD. It does not factor in the efficiency of the port. A program like Hornresp will show you what's REALLY going on, which is that the port loses efficiency if it's too small. Which means that you end up with a box that's unnecessarily complex and not very efficient, unless you use a really big port.
Long story short - bandpass boxes work a lot better with those woofers from the 80s and 90s, which didn't have a lot of excursion, and had a high VAS.
Here in the 21st century, tapped horns work very nicely. Bandpass boxes which use passive radiators instead of ports are great too.
I'm not the only one that's thinking this BTW. Geddes has a few bandpass patents, and he's switched from ports to passive radiators. Bose is in the same boat, and has switched from dual reflex (aka 6th order) bandpass to transmission line enclosures.
And just about everyone else is doing small sealed subs.
I have a tapped horn design for the Alpine on my web site, and I have purchased a set of the woofers which I intend to build soon.
In my 25 years of working in this industry, I've listened to thousands of cars and I can count the ones that sounded great on two hands. Most of them have serious problems and some of the worst ones are IASCA winners... 50% of these guys have plans to change all the equipment in their cars because they don't sound good. In every case so far, none of the equipment has been the cause of poor performance. In every case, it's the installation, the adjustments or the system design. AW
Thanks for the feedback on this Patrick. You are obviously correct as subwoofery's modelling shows.
I was looking at bandpass because in '94 I had 2 pioneer 8s (can't remember the model) in 4th order bandpass boxes and they were truly amazing; I was hoping for a repeat
Sealed it will be. I just need to figure out the best volume to run 3 of them and whether my amp will be enough...
My SWR-823D in 0.41ft^3 (sealed) lined with R13 fiberglass insulation sounds great! You have a great product here. I'm running it in my dash w/only 160watts RMS. Going to try 300 on it later and see if there's a difference.
My SWR-823D in 0.41ft^3 (sealed) lined with R13 fiberglass insulation sounds great! You have a great product here. I'm running it in my dash w/only 160watts RMS. Going to try 300 on it later and see if there's a difference.
So glad I found this sub.
Is the 0.41 cu.ft. based upon overall interior cu.ft. dimensions (i.e. without reducing the space for the speaker)? If so, what is the sub box tuned at (hertz level)?
Bandpass boxes are pretty tough to implement when a woofer has a low VAS and a lot of excursion. That's because the port gets BIGGER as the VAS gets smaller! So all of that hard work that you've invested in reducing the box size is offset by the port!
Making things even more difficult, a sub with a lot of xmax needs a really huge port, in order to move all that air.
This is one of the problems with WinISD. It does not factor in the efficiency of the port. A program like Hornresp will show you what's REALLY going on, which is that the port loses efficiency if it's too small. Which means that you end up with a box that's unnecessarily complex and not very efficient, unless you use a really big port.
Long story short - bandpass boxes work a lot better with those woofers from the 80s and 90s, which didn't have a lot of excursion, and had a high VAS.
Here in the 21st century, tapped horns work very nicely. Bandpass boxes which use passive radiators instead of ports are great too.
I'm not the only one that's thinking this BTW. Geddes has a few bandpass patents, and he's switched from ports to passive radiators. Bose is in the same boat, and has switched from dual reflex (aka 6th order) bandpass to transmission line enclosures.
And just about everyone else is doing small sealed subs.
I have a tapped horn design for the Alpine on my web site, and I have purchased a set of the woofers which I intend to build soon.
Is the 0.41 cu.ft. based upon overall interior cu.ft. dimensions (i.e. without reducing the space for the speaker)? If so, what is the sub box tuned at (hertz level)?
0.41 was gross.. So 0.36ft^3 after sub displacement.
Not exactly sure. It's a low 50's F3.. but being sealed tends to give you a larger F3... I bumped the 20-35hz a bit using EQ and it really does give a clean punch down low. Very surprising for the woofer diameter.
You want your passive to be the next size up or two from the size of the active speaker you are using. And/or you will need to use multiple PRs. Your sole output will be from the passive so you want it to displace as much or more than the active speaker you are using.
With an 8" active speaker, I would want a 10 or 12" PR with a lot of excursion.
You want your passive to be the next size up or two from the size of the active speaker you are using. And/or you will need to use multiple PRs. Your sole output will be from the passive so you want it to displace as much or more than the active speaker you are using.
With an 8" active speaker, I would want a 10 or 12" PR with a lot of excursion.
Yeah I know but I was thinking about using 4 x 8" PR for 2 x 8" driver in order to keep the enclosure "shallower"...
Kelvin
PS: Do you know where I can download SPEAK? Tried a small search but did not find it yet...
NVM, found it... Lucky there's web archive
Lycan
Quote:
I'll repeat it for the miliionth time : All amps do NOT sound the same ... It's astonishing to me that nobody understands this
Re: Alpine SWR-823D / 843D 8" Subwoofers
anyway I kept it like so... 
- smaller and you might experience port noise... 
Now how to fit a port tuned to 20hz in a .2 box
Linear Mode
