Franken SVS project

Ron Temple

Last a month I tried to help a buddy sell his GR DIY sub here and elsewhere with no takers. It's a shame no one had a need. Anyway, he decided to strip the box and pass it on to me and another friend as a project. So we are going to pickup another GR passive, drop in my spare SVS 12.2 driver and power this with a Rhythik 350w plate amp that my friend has lying around.

Per TomV at SVS it will probably be very close to an PB12+ in output and SQ in this 4 cube box, w the PR tuned to 20hz. It will look exactly like the pictures except with the aluminum driver(maybe we'll spray paint it).

It will take at least 3 weeks, since we need to order the PR and my friend needs to order the 1000w PE amp to replace his Rhythmik.

Cost: Box = $100, PR = $50, Amp = $150, Driver = priceless.

Once we each play with the new sub, we'll probably pass it on since neither of us have the room to run duals at this time. It's gonna be fun though.

http://new.photos.yahoo.com/jefflam79/album/576460762369115983

ohskigod

cant see the results being bad. I did somewhat the same thing, just a different path. My main sub in my theater was an Adire Audio Shiva in a 142.5 ltr box I made myself (using Adire's plans). My great room is kind of large, and while the sub performed well, I needed a second sub to fil in some holes.

when the new SVS plus driver came out, and some old plus drivers were sold, I bought one. I measured my bos and compared it to the exterior dimentions of an SVS PB12+. close enough for me to take a chance in dropping this driver in.

sure enough, the plus driver fig like a glove, no alterations to the box or bracing was needed (I was thinking I would have to cut the bracing a bit to make it fit.....bigger magnet and all)

I was flat out STUNNED by the result. no need for a second sub. Powered by a 500 watt plate amp, thing thing digs deep, and does it loud when needed. If that box you have doesnt fly (I doubt it, but just in case), you can buile the 142.5 ltr box from adire and it will work like a charm.

good luck on the project

ohskigod

that box is a beaut by the way

Ron Temple

I asked Tom about the PR/sealed design vs a port. His only comment was just don't use a 500w amp since the PR would be overdriven, also, I'm only losing 1 db.

Yeah, I think it will work w/o too much re-work .

I listened to the sub as shown, it was pretty damn good with the GR driver. I'm not sure can do any better, but maybe...

I remember reading about your upgrade...so I thought I'd post this one too.:)

ohskigod

must be more efficcient I guess with the PR design (I would love to hear that by the way, never heard a PR sub design before)

Mine sucks up the 500 pretty well with no signs of over exertion, but mine is ported (a big port too )

either way, cant see it not kicking arse. maybe a little less overrall spl, but probably faster and a little smoother with the PR (betcha it would be GREAT for music as well), who knows. definitly report back when that bad boy is up and running

ohskigod

anonymouse wrote:

The 1000W PE Amp is a lot more than $150.

the thousand watt would probably be WAAAAY overkill. that Rythmik he has speced will be perfectly fine. even my 500 watt on the ported design is more than enough. if it was a very tiny box (sealed), a 1000 watts might be needed, but that box is 4 litres and is in no way considerred a small box application. But hey, I'm no expert

Ron Temple

anonymouse wrote:

The 1000W PE Amp is a lot more than $150.

Yep, I think he's paying around $400 for that amp. He's replacing his Rhythmik 350 currently driving his DIY Tempest 15 sonotube. The Rhythmic 350 was the same amp that's been stripped out of the box. $150 is what he would sell it for.

Ron Temple

ohskigod wrote:

must be more efficcient I guess with the PR design (I would love to hear that by the way, never heard a PR sub design before)

Mine sucks up the 500 pretty well with no signs of over exertion, but mine is ported (a big port too )

either way, cant see it not kicking arse. maybe a little less overrall spl, but probably faster and a little smoother with the PR (betcha it would be GREAT for music as well), who knows. definitly report back when that bad boy is up and running

The SQ and output of the GR sub reminded me of the Velo DD15, but with a bit more kick down low. Very tight mid and upper bass along with all that extention. The SVS driver is a monster from about 15hz, but might not be as articulate from 50hz up. I'll definitely report back as this thing progresses.

Ron Temple

After having a routing adventure to get the SVS driver to fit, we got the sub put together today. It plays super clean and very tight. The sealed PR design makes this a very musical sub without quite the pant shaking impact of the ported versions. Also, we discovered my buddies new room with vaulted ceiling is a problem. His DIY Tempest 15 which was flat to 16hz in his previous house has virtually no output at the LP below 25hz...neither does the Frankenplus. When I get it over here, we'll test it again. Since both subs are subsonic capable, it's got to be the room.

Overall, the sub sounds better for music than the Tempest. It reminds me of the DD15 I played with for about a month.

Cost of the project:

Box - $100
Amp - $171 shipped
PR - $56 shipped
===============
$327.00

The 12.2 driver has some value as well so for ~ $400, I will have a very nice sub to use for awhile and sell down the road. Who knows, I might like it better than it's ported cousin.

Pictures will be up when it gets here.

danger boy

I did basically the same exact thing with pretty decent results. Although not a true SVS box sub... it handles bass output quite well.

I have an Adire Audio Dharman box sub. and less than a year ago i replace the driver with the SVS 12.2 one. it's been very nice ever since. No complaints. I don't see any reason to "upgrade" to a true SVS at this time.

Cool project guy.

ohskigod wrote: »

cant see the results being bad. I did somewhat the same thing, just a different path. My main sub in my theater was an Adire Audio Shiva in a 142.5 ltr box I made myself (using Adire's plans). My great room is kind of large, and while the sub performed well, I needed a second sub to fil in some holes.

when the new SVS plus driver came out, and some old plus drivers were sold, I bought one. I measured my bos and compared it to the exterior dimentions of an SVS PB12+. close enough for me to take a chance in dropping this driver in.

sure enough, the plus driver fig like a glove, no alterations to the box or bracing was needed (I was thinking I would have to cut the bracing a bit to make it fit.....bigger magnet and all)

I was flat out STUNNED by the result. no need for a second sub. Powered by a 500 watt plate amp, thing thing digs deep, and does it loud when needed. If that box you have doesnt fly (I doubt it, but just in case), you can buile the 142.5 ltr box from adire and it will work like a charm.

good luck on the project

ben62670

Where can you get the SVS drivers?

Ron Temple

ben62670 wrote: »

Where can you get the SVS drivers?

There were a bunch around when they offered a cheap upgrade to the new in house drivers. Probably pretty scarce now, but you might check ebay. I sat on mine for about 8 months. SVS won't sell replacement drivers to anyone that doesn't own one of their subs.

Ron Temple

I have it now, put in the same corner as my cylinder sat. Excellent sound quality, very tight, not as much output, but plenty of headroom. I ran a FR graph and it looks like rolloff begins around 28hz and sinks out of sight at 25hz. Emailed Tom and Ed at SVS and Danny from GR. It seems we didn't load the PR to the correct value to tune the box low enough. Hopefully, one of these guys will be able to help me tweak this.

On a more positive note...I calibrated both subs together and am now getting extremely flat response from 18 - 80hz, with a slight suck out smoothed out, so that I hear the entire bass note, not just the peak frequencies. I'm now hearing harmonics from bass string plucks I couldn't catch before. Oh, the bass is fairly powerful too .

Charts attached.

engtaz

NIce work