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Discussion Starter #1 (Edited)
Im struggling to get a good box design that can place my existing sub (Dayton rss390-hf 15) in the closet and vent into the room. 4th order working within 11cf I get a peaky response between 20-40hz. Ported response is still a fantastic 20hz up and flat..But how does that then vent into the room. At least without a giant 15" hole in the wall?

the space


The sub shown can almost fit as it is behind that wall its currently in front of. Thats the location I plan to build the new box for. Its already the a/v cabinet so it works well. But I need the sound only going to the media room, not the room behind it.



Its a closet in one of the spare bedrooms I converted to hold the a/v equipment. The space below the shelving is 24" high, 20" deep and 42" wide.

Any ideas? My next option is a THT table or something because I dont want to lose any output, just try to keep the space functional. The existing box is a bit of an eye sore.

version one subwoofer build found here:; http://www.hometheatershack.com/for...d-projects/62526-rss390hf-hpsa500-t-line.html

Bash 500s amp: http://www.parts-express.com/bash-500s-digital-subwoofer-plate-amplifier-500w-rms--300-752

Dayton RSS390-hf 15: https://www.parts-express.com/dayton-audio-rss390hf-4-15-reference-hf-subwoofer-4-ohm--295-468
 

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ARe you trying to use the whole space that you have shown in your bottom picture?

If I HAD to use this location I would just build an IB cabinet. IB can do well in a closet but its a matter of knowing what your wants are.
 

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Discussion Starter #3 (Edited)
ARe you trying to use the whole space that you have shown in your bottom picture?

If I HAD to use this location I would just build an IB cabinet. IB can do well in a closet but its a matter of knowing what your wants are.
I dont recall how this driver measured IB. However, the a/v shelving is open to the main room, I dont think it would be as separated as needed to be a true IB setup. It doesnt have to use the whole space, I just measured it and that gets me 11.6cf of potential volume.

VAS is 7.49, 4x that is about 30cf. I dont think I can swing that.
 

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Are you apposed to putting an air return vent over the driver and port exit ? You can make a window type frame to mount enclosure to the wall .
 

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Discussion Starter #5
Are you apposed to putting an air return vent over the driver and port exit ? You can make a window type frame to mount enclosure to the wall .
Thats about all I can come up with, is somehow have the box sealed up into the room but not bolted to the wall. The thing I cant figure out, is the speaker is 15", even a large air return vent is probably 10X24. Im not sure how to tie those two together.

maybe build out the box in front of the driver to allow it movement but shrink down to vent size. Hopefully that wouldnt have to negative of an effect on the sound. Do the same with a port and bolt the box to the concrete
 

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My return vent is 23"x23" . I saw that you reworked your sub box in another thread . You really need your vents right by the sub so they can fire through the wall . I saw in another thread you put the ports on other end of box . I'm not sure how to get the port energy into room without making an open cavity for them or extend them which we both know wont work . If your sub amp is indeed dead would you consider a berhinger pro amp like the dsp versions. you can limit power , eq , crossover , and control phase . I have one and like it !!
 

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Discussion Starter #7
My return vent is 23"x23" . I saw that you reworked your sub box in another thread . You really need your vents right by the sub so they can fire through the wall . I saw in another thread you put the ports on other end of box . I'm not sure how to get the port energy into room without making an open cavity for them or extend them which we both know wont work . If your sub amp is indeed dead would you consider a berhinger pro amp like the dsp versions. you can limit power , eq , crossover , and control phase . I have one and like it !!
Well if I can get a vent cover that size I shouldnt have any issues! I reworked the box from the t-line to lower tuned ported box, and switched from the dayton amp to the bash. I wish I had gone with a pro amp! I can build a new box to fit the new space and I think I have some ideas for directing the sound through the vent, without coupling the box to the wall and rattling everything.
 

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Do you have the highpass frequency and amount of boost that the bash has ? It is important to have it when designing a box and tuning . I have read info that most of them have a 12db octave highpass at 17-18 hertz . Most have boost around 22-25 hertz 1.5db-3.5db .
 

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Discussion Starter #9
Do you have the highpass frequency and amount of boost that the bash has ? It is important to have it when designing a box and tuning . I have read info that most of them have a 12db octave highpass at 17-18 hertz . Most have boost around 22-25 hertz 1.5db-3.5db .
I have looked for that information and found different results. I hope its a model that boosts in the 20s not 30hz region. I think the highpass is at 18hz on this model.

Im thinking I can do a 20" square vent below the a/v rack, and put a slot port coming out of the a/v rack lowest open area. That is assuming I dont have room for 2 4" ports directly next to the driver.

or do this 24x14 vent. the ports would have plenty of space next to the driver and may look nicer.
http://www.homedepot.com/p/SPEEDI-G...-White-with-Fixed-Blades-SG-2414-FG/202542262
 

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Yes i would put the ports and driver next to each other if possible , just so 1 vent covering will work . What size of an enclosure are you wanting to use ? Do you have winisd to do some modelling ? I have been comparing a 6 cubic foot tuned to 17 and a 11 cubic foot tuned to 16 . The bigger box will play lower but you may have excursion trouble if you push it hard .
 

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Discussion Starter #11 (Edited)
The current box is about 11cf and sounds nice and gets low. I modeled it in winisd and it appeared flat to 18 if I remember right. But Im also not very good at using winisd. I have room for 11cf in the space, however I have found that if I push it I do need to monitor excursion. Maybe something in between would get the job done?

A reputable member of the boards (or several) also modeled the existing box and gave it the ok. But its not a pretty looking thing, and I'd love a stealthy install.
 

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Model the bigger box and go to the eq filter tab and make i highpass at 17.5 hertz 2nd oder then make a parametric eq at24 hertz (just guessing) with a (q of 1.4) and about 2.5-3 db of boost and you will see the excursion . Power of 500 watts . Not knowing the boost frequency and q we are just guessing unless someone else knows the parameters for sure . I am not trying to be a pain , i have run my ported subs with no highpass and not the right amount of boost . It scared me sooo bad when i heard the sub bottom wham wham loud .
 

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Discussion Starter #13
I appreciate the input. I had this sub bottom out one time, I know the gain was set too high due to issues with an old receiver being stuck in whatever settings it was. Terrible scary noise, so Im extra careful now.

I'll have to DL WinISD pro I think to get those features. I'll try to model it today, see what works out. Port length is going to be somewhat of an issue I think, but I have the space to make the box bigger to compensate too.
 

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Discussion Starter #14
spare few minutes tried modeling some different ideas to see how it fits. End up with about 8cf after driver and port displacement..though Im looking it over and questioning the drivers displacement I entered.



3x10x22" slot port
 

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I wish I knew how to transfer my modelling from winisd to here . Im guessing .2-.3 cubic feet . There have been guys that say a s;ot port will end up tuned lower than modelled . Usually about 2 hertz lower . In my sons box for the ho's we wanted 30 hertz but it is about 28 hertz using test tones and watching excursion. I have also read by several people that the xmax for the hf series is more like 16-18mm . I do wish your dayton amp would not have died because then we know specifics of highpass and boost. the 8 cubic feet box and those port dimensions show a tuning of 19.5 but I bet real world will be 17ish , are you figuring any fill in your modelling because it will help lower a half a hertz or so . Some the things I am saying are quotes from some very brilliant people so i am not just spouting off .
 

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Discussion Starter #16
One answer to a high-pass filter or bass boost on the bash on parts express:
"The BASH 500 Watt Sub amplifier does not contain a selectable low frequency roll off switch. It is pre wired to provide -0- db of boost and can be modofied at R17 & R18 to obtain +1db - +5 db of boost."
"Unfortunately, we do not stock the amplifier with the bass boost already in place, you would have to make the modifications."
"Yes, it is centered around 18 Hz." (subsonic filter)
"The high pass filter on the Bash amplifiers is set at 18 Hz."


I read through a all of the Q&A on PE and it seems the amp has no bass boost at all, and 18hz highpass.

I fully intend to use fill, I always have and it seems to make an improvement in sound (i cant say exactly what it is).

This will also be located in the corner of the room, I think with room gain, it may outperform its existing 11cf box.
 

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Did u get the pro version going ? With no boost and highpass at 18 it should be a very nice combo . I modelled it tuned to 17.5 because if you use a slot port and add some wall dampening you will be tuned to highpass and never have to worry I dont think . Are you planning on mounting it in the box or outside ? Some say it can start to rattle .
 

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Discussion Starter #18
Im debating mounting the amp on its own so I can more easily access it. I havent had any issues with it mounted in the enclosure so far though. I have winisd pro alpha, and am having issues with it shutting down, I have to force quit the program.
 

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Discussion Starter #19 (Edited)
Modeling some options for this enclosure, Im really only doing slot port since port velocity was too high on the existing box. Fitting a 6" or 8" port would be tough.

Should I be worried about the small dead space beside the slot port?
front view


top view


complete minus top


complete


Just wondering if the vent could be done in a better way.
 

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Discussion Starter #20 (Edited)
I will probably do dowel bracing internally, and add a 1/2" thick front baffle for stiffening help as well. I will probably get some 1/2" thick adhesive backed foam strips and go around the front of the box when it comes time to install so that whatever contact it makes with the wall is hopefully canceled.



The vent outside edge will get a nice round over from the router. I do need to double check the port length because of the 90, I cant recall the change in length a 90 creates.

I may move the port to the side in line with the sub rather than below it. Then I can utilize a 16"x25" vent cover and height is a limiting factor. I had to take into account the trim work in the listening space.

https://www.menards.com/main/heatin...432075905-c-6879.htm?tid=-1708257915515829862
 
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