Newbie who likes to DIY

[Merc1973]

Hello, I'm not an audiophile but i am always interested in improvements and upgrades. I have made some frugal purchases in the past with out research, but now we have the world of forums.

I have an AR (acoustic research) s112-ps (down firing 120w 12"), 8 years old, never pleased with sound and is very directional. Pulled it apart today, what a POS!!!! you would laugh your butt off if you see what i see.... The enclosure seems salvageable, i think. I plan on doing a cheap DIY, upgrading either these subs and amps:

Dayton SA240 240W Subwoofer Amplifier
or
Dayton SA100 100W Subwoofer Amplifier

sub:
Dayton
SD315-88 12" Shielded DVC Subwoofer

or
Dayton QT305-4 12" Quatro Subwoofer 4 Ohm

Any suggestions?
...also need some acoustic foam/poly fill-it never had any!!!.

 

[WmAx]

Hello, I'm not an audiophile but i am always interested in improvements and upgrades. I have made some frugal purchases in the past with out research, but now we have the world of forums.

I have an AR (acoustic research) s112-ps (down firing 120w 12"), 8 years old, never pleased with sound and is very directional. Pulled it apart today, what a POS!!!! you would laugh your butt off if you see what i see.... The enclosure seems salvageable, i think. I plan on doing a cheap DIY, upgrading either these subs and amps:

Dayton SA240 240W Subwoofer Amplifier
or
Dayton SA100 100W Subwoofer Amplifier

sub:
Dayton
SD315-88 12" Shielded DVC Subwoofer

or
Dayton QT305-4 12" Quatro Subwoofer 4 Ohm

Any suggestions?
...also need some acoustic foam/poly fill-it never had any!!!.

What quality of subwoofer do you want to build? The drivers you linked are rather mediocre, though perhaps better than the driver in your AR unit. Also, you need a more powerful amplifier to take advantage of a high quality subwoofer in most cases. A very high performance/quality system can be built using the superb Infinity Kappa Perfect VQ 12" driver and a 500 watt O Audio BASH 500 watt amplifier. The O Audio has a built in adjustable sub-sonic filter; a very important feature to prevent over-excursion under the tuning frequency of high powered ported systems.

http://www.oaudio.com/500W_SUBAMP.html

The cabinet must have a huge port mouth, which means a folded slot port. Failure to include this will result in significant compression around the tuning frequency of the system.

The Kappa Perfect driver suggested does not have huge power handling or excursion; it has moderate power ability and moderate excursion. The real point of this driver is that it's excursion is completely linear - it has incredibly low distortion and it will sound the same at low or high SPLs as a result. This is a sound quality driver - but it will also produce very substantial SPL compared to the retail competition. For a ball park example: in a smaller to medium size room, it has been measured at around 120dB at 20Hz if corner loaded and in the right cabinet design, and powered by a very high power amplifier(This SPL was measured using a 2000 watt RMS amplifier).

The dampening materials you need are available online if you need them. These high density fiber based board materials are the only highly effective means to have meaningful dampening in this type of system for the purposes intended.

If you follow my suggestions, the result will be an extremely high quality subwoofer that you really can not improve upon from the standpoint of fidelity. The only improvements to be made are those related to having even deeper bass response and higher SPL; which will require a more expensive driver and more power, if you want to do it right.

-Chris

 

[Merc1973]

Thanks for the lengthy and in depth response. I should clarify this is probably going to be a mediocre build not much more than $200. I live in a 2 bed apartment with a medium sized living room, I want to keep the sub next to the couch. It will be for a 5.1 using Sony strdg720, muddy Polk R15s in rear, DIY Boston acoustic center, DIY-able Insignia NS-B2111. The Cabinet has only a 3" port. For Dampening should i go with Dynamat, "egg crate" acoustic foam, and poly fill?

 

[Swerd]

Thanks for the lengthy and in depth response. I should clarify this is probably going to be a mediocre build not much more than $200. I live in a 2 bed apartment with a medium sized living room, I want to keep the sub next to the couch. It will be for a 5.1 using Sony strdg720, muddy Polk R15s in rear, DIY Boston acoustic center, DIY-able Insignia NS-B2111. The Cabinet has only a 3" port. For Dampening should i go with Dynamat, "egg crate" acoustic foam, and poly fill?

It is rare that you can find a woofer that is ideal for an existing cabinet. What is the internal volume of your cabinet, and the length of the 3" diameter tube?

It is usually easier to make a new cabinet than to try and find a woofer that can work with your existing cabinet. Parts Express already has cabinet designs for both those two drivers listed on their website (see links below). Apparently both can work in either as sealed or vented, but both require a smaller sealed cabinet than a vented cabinet.

I've heard the 12" Quattro in a sealed cabinet driven by the 240 watt plate amp you mentioned, and its not bad. I haven't heard the 12" DVC.

12" Quattro
Sealed about 1 ft³

Vented about 2 ft³ with a 3" diameter × 9" long tube


12" DVC
Sealed about 1.2 ft³

Vented about 2.5 ft³ with a 3" diameter × 7.7" long tube

 

[Merc1973]

Dimemsions are close to both vented designs (17x17x17, external). However i would need a longer vent tube, it's only 5". How much differnece in sound would there be by having the position of the sub: down vs. front firing?

 

[Swerd]

Dimemsions are close to both vented designs (17x17x17, external). However i would need a longer vent tube, it's only 5". How much differnece in sound would there be by having the position of the sub: down vs. front firing?

I'm not sure about that. Call Parts Express technical help, 800-338-0531 and see if they know.

 

[Merc1973]

Dimensions are close to both vented designs (17x17x17, external). However i would need a longer vent tube, it's only 5". How much difference in sound would there be by having the position of the sub: down vs. front firing?

OK so i had my GF measure and actual measurements are 14x14x12 internally, sorry. Is it worth it or not?

 

[Swerd]

OK so i had my GF measure and actual measurements are 14x14x12 internally, sorry. Is it worth it or not?

Parts Express says the 12" Quattro sealed cabinet should be 13.3 x 13.3 x 14.1, and the 12" DVC sealed cabinet should be 14¼ x 14¼ x 14.8. Assuming your cabinet walls are ¾" thick, this isn’t far off. I would guess that the 12" Quattro would be alright in your cabinet. Find a way to seal the 3" tube. Stuffing a sock in it will block air flow but won’t create a seal. A wad of closed cell foam, like a Nerf football, might do the job. For very little cost, a Plumber’s Test Plug will make an air tight and water tight seal. Look in a store that sells plumbing pipes and various parts (Lowe’s or Home Depot), and buy a 3" Plumber’s Test Plug. This link shows what they look like. You may have to file the metal parts a bit to get it to fit.

I can't say if it will be worth it, but you could easily try it.

 

[Merc1973]

Parts Express says the 12" Quattro sealed cabinet should be 13.3 x 13.3 x 14.1, and the 12" DVC sealed cabinet should be 14¼ x 14¼ x 14.8. Assuming your cabinet walls are ¾" thick, this isn’t far off. I would guess that the 12" Quattro would be alright in your cabinet. Find a way to seal the 3" tube. Stuffing a sock in it will block air flow but won’t create a seal. A wad of closed cell foam, like a Nerf football, might do the job. For very little cost, a Plumber’s Test Plug will make an air tight and water tight seal. Look in a store that sells plumbing pipes and various parts (Lowe’s or Home Depot), and buy a 3" Plumber’s Test Plug. This link shows what they look like. You may have to file the metal parts a bit to get it to fit.

I can't say if it will be worth it, but you could easily try it.

Thanks for your help, I will give it a shot, I know this build isnt up to most standards, but anything should be better than AR-quality ( i think i my farts have more bass). I will post pics of the the build.

 

[Alex2507]

( i think i my farts have more bass). I will post pics

I thought things were just about to get out of hand ...

 

[Merc1973]

that would be a sight to see... LOL all i need is a bic lighter.....

Yeah i realize i should start from scratch with the cabinet, but this is a rough draft. It certainly won't be my last DIY sub. So i ordered the Dayton 12" quatro and the Dayton 240w plate amp. While i wait on shipping i got some high density acoustic foam (Auralex v-wedge alternating the pattern) and lined the interior, some poly fill, and a plumbers test plug to seal up the port. WOW, i didnt realize this thing could actually sound better....than my own flatulence..... No more boomy-ness and a decrease in resonance, it even hits lower before i could barely hear anything below 80Hz. Cant wait for the replacemetn parts.

 

[Merc1973]

How much poly-fill should i stuff in to this enclosure?