SUNN 2x12 cabinet on the way

[Denis]

So, this is on its merry way to my house. What do you guys suggest for speakers?

http://longisland.craigslist.org/msg/1275317223.html

[Dave W]

An open backed cab for bass? Not to rain on your parade but Sunn's open backed cabs were from their Lead (i.e. guitar) series.

[nofi]

oh well live and learn. 50 bucks is really nothing in the world of overpriced gear and you could probably trade it or find a use for it. 15 dollars extra for the sunn logo? F this clown.

[rahock]

One more to add a negative 2 cents worth......dat aina gonna werk  sew goot:)
Rick

[Denis]

Damn, I guess I'm just a stupid newbie. I completely overlooked that open back... 

[Pilgrim]

Not a problem!  Buy some black Tolex, cut a new complete back for it out of 3/4" birch plywood, install Tolex on the wood and enclose the back.  Voila!  Semi-instant bass cab.

Whether it would be desirable to add an internal baffle to somewhat separate the two speakers acoustically is another question.  In my 60's Bassman 2x15 cab (similar design) there was such a baffle - really just a piece of 3/4" plywood that was mounted horizontally (when the cab was standing) equidistant between the two speakers.  It didn't seal off each half, it just came within an inch or so of the back and an inch or two of the cabinet sides.  I have some pix but they're in the computer at home and not available online...yet.  Send me a reminder and I'll post them.

Others may have advice to share about whether it is desirable to partly or fully isolate the speakers from each other in the cab.

After closing the back, you can do some figgerin' with WinISD Pro (see http://www.linearteam.dk/default.aspx?pageid=winisdpro) and check the performance of various speakers.  Good luck with that program - many people use it but I keep being unable to understand it.

Note: if you're going to use this cab with the Coliseum-300, this is a GOLDEN opportunity to find speakers that you can configure to make this a 2-ohm cab!!!  That will open up all the power of the 300 to you!  Or - if you'll be using it with a separate cab, I'd configure for 4 ohms and have a more versatile cab that can be connected with just about any other cab you might own in the future...as long as you're using the Coliseum-300 with its 2-ohm tolerance.

One more thought...if you go for the 4-ohm configuration, you could buy a pair of 8-ohm speakers.  That would give you the option of wiring the cab for 4 ohms for use with the Sunn, or changing the wiring to 8 ohms if needed.

[Denis]

Whew, thanks much for your solution to my oversight! Sounds like a great idea too and yes, I'd like to see how the baffle looks (I wonder if there's such a baffle in my Fender 4x10) in your 2x15.
If I can figure out that program I will be glad to pass along anything learned from it. Wish me luck indeed!
Yes, I am definitely going to use the Coliseum with this cab although all this talk about ohms reminds me I need to go back to your comments in the other thread about the Coliseum. Haha, I was an English major not an acoustic engineer!

[Pilgrim]

Not to worry.  

Hit the excellent Shavano website: http://www.colomar.com/Shavano/index.html

And click on Construction...below that there's a whole section on wiring.

Here's the section on wiring a 2x12 cab: http://www.colomar.com/Shavano/2x12wiring.html.

I'm re-reading this page to see if I made an error earlier.....yes, I did....

Check the first two illustrations.  It appears that if you bought two 4-ohm speakers and wired them in Parallel, you'd have 2-ohm impedence.  If you wired them in Series, you'd have 8-ohm impedence.  This would work well with your Sunn as a solo cab, as you could wire for it 2 ohms....and if you really needed to use it with something else, you could change it to 8 ohms.  

I was wrong in my earlier post - you can wire two speakers for 1/2 the resistance or 2x the resistance, but not the same resistance as the individual speakers.

I'll look for those photos and post them.....I'd think the biggest issue about putting a solid back on that cab is going to be getting a good seal - and that will depend on how the original cab back is configured.  You might end up needing to mount filler strips at the top, bottom or sides (probably not all of those), which wouldn't be difficult.

[rahock]

I'd still opt for dumping it and getting a Sunn 2 15". Then you would have a REAL bass cabinet that you know will deliver . The Sunn 2 15" is definately one of the better sounding 2 15" cabs out there.
Rick

[nofi]

i had a sunn 2x15 that i liked. i think the good tone comes from the two dozen friggin screws that hold the back on.

[Pilgrim]

Here's the photo I was thinking of - this is the back of a 2x15 Fender cab I bought in 1967.  It had screws every 4-6 inches holding the back on (you can see some of the holes in the pic), and there were screws both around the edges and across the center where the baffle is located, so it was well fastened in place.  Memory told me the baffle wasn't a tight fit to the sides, but this photo seems to show that the baffle did pretty much isolate the two sides.  This cab clearly had been messed with, as it came to me with both the JBL D130F shown, and a square-magnet speaker which was not labeled but I think was a Fender speaker.   The piece of fiberglass insulation was just stuck on the back wall of the cab...not even fastened in place.

[Pilgrim]

So, Denis..............is the cab in hand yet?  how's it looking for potential modifications?