another diy sub question(s) (1 Viewer)

[Frank A]

New to diy, so please bear with me. Before I start to build a sub, I have a couple of questions. My current setup consists of an 8 inch KLH sub with a 120 watt amplifier that goes from "30-40 to 120" hrz. This sub is hooked up to my receiver which is a Yamaha RX-V 630 (about 2 yrs old). If I understand it correctly, I think that it is rated at about 75 watts per speaker (not sure how accurate that is, though). I do not plan on upgrading my receiver anytime soon.

I have been thinking about using either a Shiva or Tempest driver and combining it with a 250 watt amp either from Adire or Parts Express. If I use one of these combinations, can I hook it up to my Yamaha (I have nothing else to hook it up to) similarly to how it is now hooked up to the KLH? Will this supply me with the correct/adequate power, etc to play the sub?

If I am totally off base or way out in right field, please let me know. Depending on your answers, other questions are forthcoming.

thx, Frank

p.s. I have been reading all of the diy posts on this and other forums for the past 3 weeks or so, but at my age, I forget about 90% of what I read.

 

[GrahamT]

The Yamaha's power has nothing to do with the sub. If the 630 has a "LFE output" or "sub output" just connect that cable to the input on the sub plate amp.

I have a Tempest with 250W plate amp in an EBS alignment and it is everthing I expected. Good luck on the project.

 

[Paul His]

Frank,

The Yamaha RX-V630 does have a sub output, sometimes referred to as LFE (Low Frequency Effect) channel. It is a single rca jack at the lower left on the back.

The LFE jacks outputs low amplitude signals which will be amplified by your subwoofer amp.

Paul

 

[Frank A]

Thanks Graham and Paul. Now, next quick question(s). How "round" does the driver hole have to be in the wood. I do not currently have a router or work bench to make the hole. If I use a jig saw to cut the hole, I am sure that the hole will be somewhat "jagged" and not a true, smooth circle (all the pictures I have seen of the holes seem to show that the circles are cut almost perfect).

Will this have an affect on the setup (maybe leaks, etc. remember, I'm new to just about everything here). One other question concerning mounting the "plate amp", is it? Does it just mount to the back of one of the sides or does it have to have a hole cut into the wood side and then mount it into the hole (told you I was new)?

thx, for all your help.
Frank

 

[Wayne Ernst]

Frank, some of this depends on the actual jig saw used. For example, I have a Bosch variable speed jig saw that will cut some pretty accurate holes. Needless to say, I start with a good, solid circular line and use only about 1/3 of the power that the saw provides, so it goes nice and slow and I can maintain the saw on the cut line pretty accurately.

In regards to blocking air from escaping, if you cut a hole pretty close to the line and then use the proper gasket material, you should be fine and free of air leaks.

 

[GrahamT]

You can definitely cut a circle accurate enough for a big driver like the tempest. Use a compass to make a nice round circle and just go slow like Wayne said, and use a gasket to stop air leaks.

You will also have to cut a hole out for the plate amp and it just drops in.
Here are some designs for the Tempest
http://www.adireaudio.com/tech_papers/tempest_apps.htm

http://www.adireaudio.com/diy_audio/..._territory.htm

 

[minhG]

On cutting holes, I used a rotary tool and that worked ok. unfortunately i don't own a jig saw as nice as the one Wayone has got! I almost bought one on sale at HD last weekend, those bosch jig saws look really nice.

If you're really unsure of how close you can cut the circle, cut it out to about 1/8", and then go back with a file and sandpaper. It's more work, but then you get a very tight fit.


btw, i finished a 142L vented shiva today, when I played the 20hz tone, i shook the foundation of my 3 story-15unit apartment building, very clean, very tight. i'm scared of what a tempest would do...

 

[Chris Keen]

Check your local Lowes. I picked up a clearanced out DeWalt DW321 jigsaw today. I already have a nice Bosch that I'm not about to part with, but I couldn't pass up the price on this one. It normally sold fo $139 at Lowes (and $149 at Home Depot), and it was marked down to $39.95. I think I'm going to give it to my dad for part of a Father's Day gift. He's got an ancient Craftsman that works really well, but I think this DeWalt will be nicer.

Also, just as an FYI -- Any of you guys that are DIYer types and need tools, you should always check the tool sections at HD and Lowes and even Sears (or whatever Borg you have in your town) whenever you go in there. I'd say that 90% of the time, you'll not find any great deals on much of anything, but sometimes you will.

Aside from the DeWalt jigsaw that I picked up today, in the past 6 months, I've picked up a Porter Cable 690 router for $75 (normally ~ $140) at Sears, a Porter Cable 743 left blade circular saw for $75 (normally ~ $140) at Lowes, and various Bessey K-body clamps at HD at clearance prices (about 1/2 normal prices).

Timing is everything, but you've got to make it a habbit to look or you'll never see the deals that are there.

 

[Wayne Ernst]

Dayum, that is a very nice price for a very good saw.

 

[Chris Keen]

Wayne, no doubt. I can only say that I "got lucky" on it. Timing is everything. It was the only one that this store had left. I peeled back the mark down stickers, one layer at a time when I got it home. I was curious. I saw (whoops, a pun) that it was first marked down to $99.95, then $69.95, then $39.95. I'm surprised that it didn't get swiped at $69.95. I told my wonderful wife that I couldn't in good faith, leave that poor orphan there at $39.95. She gave me that wry smile.

BTW, we are going to DC in about a week. My wife has some conference thing up there for a week, and I am going up with her about 3-4 days early for a small vacation. I have never been, and really want to check it out. I know there's lots of touresty things to do and see. Is there any recommendations that you have of "must see and do" activities?

Thanks

 

[FredC]

I've been to DC a couple times and there are a ton of different things to see. It kind of depends on what you're interested in as to where to go, but a couple things that were interesting were Bureau of Printing and Engraving where you can see them printing money (it's only open for tours in the morning I believe), and the Renwick Gallery has some interesting pieces of modern art. I like "Game Fish"

Frommer's notes on Renwick

And of course there are all the Smithsonian museums along the mall, and the monuments.

 

[minhG]

WW2 memorial is also dedicated this weekend, fyi. but it'd be hard to miss as it's in between the lincoln and washington memorial.

one thing people always overlook in DC are the great restaurants. I think we are on par with any of the other big cities in the country.

 

[Wayne Ernst]

Chris,

The newest and biggest attraction has got to be the Air and Space museum "annex" which is located just off Route 28 - about 5 miles south of Dulles Airport.

I only live about 6 miles from there, but I haven't been there yet. Some of the great displays include: over 500 aircraft, one of the retired space shuttles, and a retired Concorde jet. Additionally, they have an iMax movie theater on site and I believe the latest flick is a Nascar movie, which should last about 40 minutes. The only downside of this new annex is that they've hired some company to manage the parking and it runs $12.00.

Also, as mentioned, the restaurants are good, too. Depends on what you are looking for, but there are lots of great ethnic restaurants in Adams Morgan of DC.