Custom build, humor me and discuss

[Nemo128]

If I'm gonna start a thread on my build, should it be in Subwoofers or DYI?

 

[WmAx]

The JLW7 8" driver recommended here is a prime solution. It is incredibly linear, and will roughly output real world, what a good 12" will normally output. It can also go very deep. It can easily be used to 18-20Hz with the right box design. NOTE: You MUST design this with large slot vents to prevent port compression. 2 or 3 of these subs would be superb for your application. They cost about $250 each from online discount retailers. I have measured 2 pair of these from different production batches and they are really about 4 Ohms. Not 3 as advertised. Also, the T&S parameter for compliance (VAS) is much lower than the factory provided specs would indicate, based on both pairs I have measured. I recommend a real 400-500 clean watts to each 8" W7.

-Chris

 

[Nemo128]

The 8W7 is almost 7 inches deep. It won't fit under the couch by itself, let alone inside an enclosure that will fit under the couch.

 

[WmAx]

The 8W7 is almost 7 inches deep. It won't fit under the couch by itself, let alone inside an enclosure that will fit under the couch.

If the excess is only 2 or 3 inches, then it's completely feasible to place the couch on 3" risers. I think most subs of the quality/output you may want will be a tiny bit too deep.

On a slightly different note, if you are considering those super slim sub drivers that are made for special purpose applications; these seem to almost always be a large compromise in performance, and I'm not aware of a single one that has been measured/verified to be of high performance.

-Chris

 

[Alex2507]

The 8W7 is almost 7 inches deep. It won't fit under the couch by itself, let alone inside an enclosure that will fit under the couch.

Cut a hole in the floor.

 

[Nemo128]

Sorry but I'm sticking to the low pro idea. WAF is maximum with that, she's not going for risers on the couch, and I don't desire enough output to shake the house. It's just not necessary. I doubt I even run my system beyond 65dB, the woman doesn't like loud. That DYI project on PE didn't seem so bad.

 

[Alex2507]

the woman doesn't like loud.

This one should be tied up in the attic.
You could hear a pin drop ...

 

[MidnightSensi]

Sorry but I'm sticking to the low pro idea. WAF is maximum with that, she's not going for risers on the couch, and I don't desire enough output to shake the house. It's just not necessary. I doubt I even run my system beyond 65dB, the woman doesn't like loud. That DYI project on PE didn't seem so bad.

I think you should stick with a low profile driver. The form factor is what makes this project cool in my opinion.

Even if you just design this subwoofer for low levels, we should optimize it for your volume under your couch. She might not be home one day while your watching a movie and you'll want to crank it a bit.

Also, do you have a way to get speaker wire under your couch without them being visible? I think it might, depending on how the layout is, be easier to do a passive subwoofer because then there isn't a power cable needed.

 

[Nemo128]

I think you should stick with a low profile driver. The form factor is what makes this project cool in my opinion.

Even if you just design this subwoofer for low levels, we should optimize it for your volume under your couch. She might not be home one day while your watching a movie and you'll want to crank it a bit.

Also, do you have a way to get speaker wire under your couch without them being visible? I think it might, depending on how the layout is, be easier to do a passive subwoofer because then there isn't a power cable needed.

I hadn't even thought of a seperate amp. Great idea!

I showed the woman the Yammy Pro amps that Chris loves, and she highly approved. She liked the more industrial look of them.

So far, I am liking these Pioneer shallow mounts. According to WinISD, 2 of these will provide more outout at lower frequency than using even 5 of the Tang Band drivers. I want to start a new thread somewhere to better track progress. What section should I put it?

Also, sorry Chris, but risers under couch = "I don't want f*cking spacers under my couch." ~SWMBO

Whatever I do has to look nice, she cares less about the money involved than about the aesthetics of it.

 

[WmAx]

I showed the woman the Yammy Pro amps that Chris loves, and she highly approved. She liked the more industrial look of them.

Note: you can even take off the rack mount wings on the sides that may look out of place in your regular rack. Just a few heavy screws hold them on from the side which come off easily. Note these pro amps have no fan noise in operation like most pro amps. However, you need to remember these amps only have pro level line inputs, and your receiver needs either high output voltage capability, or you need to use a device like the DCX2496 or a consumer to pro voltage adapter to feed the amps.

So far, I am liking these Pioneer shallow mounts. According to WinISD, 2 of these will provide more outout at lower frequency than using even 5 of the Tang Band drivers.

Please remember that WinISD is showing theoretical output. Most drivers can not actually produce near the maximum output that WinISD displays, as in the real world, most drivers have relatively non-linear motors that lose substantial motor power after just 1/3-1/2 their rated x-max and at the same time fall prey to suspension non-linearity.

-Chris

 

[Nemo128]

You guys didn't forget about me right? I am very serious about this build, but I'm a little blind. What should I do next?

 

[lsiberian]

You guys didn't forget about me right? I am very serious about this build, but I'm a little blind. What should I do next?

You could try using a 12.1 Perfect. (shameless plug). It's about 4" deep Just line the back with something like rockwool if you can. And run a port around the box

Your port can be 3" x 12.5" go 42.5 feet I have a picture of your sub in my mind. Place the kappa under your seat. Or in the middle.

with the box it fits very nicely into that size.

 

[annunaki]

The pole vent, on most any speaker that uses one, needs at least .75" of clearance from any object. Go inside of that and cooling as well as unwanted noise can set in.

 

[WmAx]

You could try using a 12.1 Perfect. (shameless plug). It's about 4" deep Just line the back with something like rockwool if you can. And run a port around the box

Your port can be 3" x 12.5" go 42.5 feet I have a picture of your sub in my mind. Place the kappa under your seat. Or in the middle.

with the box it fits very nicely into that size.

The Kappa Perfect 12.1 is 7" deep.

-Chris

 

[lsiberian]

The Kappa Perfect 12.1 is 7" deep.

-Chris

Yeah I just realized that. Back to the risers.

 

[Nemo128]

SWMBO = "Sure, you can put risers on your new bed."

In other words, no risers for the couch.

I still think a build with the Pioneer shallow mounts could work out great.

Behringer EP1500 to power them means more cabinet room since there's no plate amp.

 

[WmAx]

SWMBO = "Sure, you can put risers on your new bed."

In other words, no risers for the couch.

I still think a build with the Pioneer shallow mounts could work out great.

Behringer EP1500 to power them means more cabinet room since there's no plate amp.

Okay, I have been trying to solve your problem, and I have a feasible option for you, assuming your couch is wide and deep enough to get about 5.3-5.4 cubic foot cabinet underneath the unit. This should be possible.

The driver to be used is the 8" Dayton RS subwoofer, model RSS210HF-4, part number 295-456. It is about 5" deep according to the specification sheet. It is highly linear. You will use 4 of these units in a 5 cubic foot ported cabinet using 2 x 25" 4" ports. The air velocity of the ports is kept reasonably low to prevent compression/noise and 4 of these drivers will produce substantial SPL. Response will be about -3dB at 28Hz, -6dB at 23Hz, and -9dB at 20Hz. As you will notice, the roll off is shallow, giving you substantial output at 23Hz, instead of the rapid rolloff after the -3 point on traditional ported alignments. I used an over-dampened alignment to give the extra extension, and also, this type of alignment will sound subjectively 'tight' like a sealed alignment.

400-500 watts RMS is sufficient. The O Audio BASH500 amplifier is recommended. It has the subsonic filter that is required for this subwoofer alignment.

Total project cost would run around $750-$800 including drivers, amplifier and all building materials.

-Chris

 

[Nemo128]

The driver to be used is the 8" Dayton RS subwoofer, model RSS210HF-4, part number 295-456. It is about 5" deep according to the specification sheet. It is highly linear. You will use 4 of these units in a 5 cubic foot ported cabinet using 2 x 25" 4" ports. The air velocity of the ports is kept reasonably low to prevent compression/noise and 4 of these drivers will produce substantial SPL. Response will be about -3dB at 28Hz, -6dB at 23Hz, and -9dB at 20Hz. As you will notice, the roll off is shallow, giving you substantial output at 23Hz, instead of the rapid rolloff after the -3 point on traditional ported alignments. I used an over-dampened alignment to give the extra extension, and also, this type of alignment will sound subjectively 'tight' like a sealed alignment.

400-500 watts RMS is sufficient. The O Audio BASH500 amplifier is recommended. It has the subsonic filter that is required for this subwoofer alignment.

Total project cost would run around $750-$800 including drivers, amplifier and all building materials.

-Chris

Sounds great, only problem I see is the mounting depth of the sub. The couch is exactly 6" off the ground, so I don't think I'd have 5" of depth for the subs. I know the constraints suck, but it's all I have to work with.

What about if the underside of the couch is just covered and has no actual structure along the botton? Maybe we could dimension it slightly "inside" the bottom of the couch?

 

[WmAx]

Sounds great, only problem I see is the mounting depth of the sub. The couch is exactly 6" off the ground, so I don't think I'd have 5" of depth for the subs. I know the constraints suck, but it's all I have to work with.

What about if the underside of the couch is just covered and has no actual structure along the botton? Maybe we could dimension it slightly "inside" the bottom of the couch?

Simply place the sub drivers underneath so that they are mounted firing up, and in the cavities under the couch that give a little more than 6" clearance. Be sure to use metal grills over the sub drivers, of course. Be certain that when you sit on the couch that these cavities don't sink down far enough to contact the drivers, of course.

-Chris

 

[lsiberian]

Simply place the sub drivers underneath so that they are mounted firing up, and in the cavities under the couch that give a little more than 6" clearance. Be sure to use metal grills over the sub drivers, of course. Be certain that when you sit on the couch that these cavities don't sink down far enough to contact the drivers, of course.

-Chris

IOTW. It's time to hit the gym again. Your AH hobby requires you to be a lightweight.