Converting an ampeg 810 into.........

[catrunes]

a 2x18. anybody know anybody that would do this for me? also, what speakers would be the best in that situation? i was looking at the Ciare 18.00 SW, but i dont know all that much about speakers.

[David Houck]

My guess is that you would be better off just selling the 810 and purchasing a used 2x18.  The baffling and porting of cabinets are designed to work with specific speakers.  So my guess would be that the labor and expertise involved in redesigning the existing cabinet so that it's tuned to match the characteristics of a particular 18 speaker would be significant.  Plus add in the cost of some materials as well.
 
But that's just my guess.  I'm not an expert on speaker cab design.

[2400wattman]

I concur with Dave, also Ampeg's cabs are made from pressed wood so trying to work with that would be pointless. It's made to be cut once and only once(no modifications)! Bass Northwest has an Energy Group 2x18 for sale and would be worth checking out. As far as speakers go, JBL(first choice), EV or RCF which is what EAW uses in their boxes, a great speaker that's not as much as JBL or EV but delivers killer performance.  
Take care

[keurosix]

It can be done. You would need to replace the baffle boards with new ones.(The front panel the speakers mount to.) Best to consult with a speaker designer who would calculate the best configuration for a specific driver. An 18 requires a certain volume cab to work as designed, and an infinite baffle (sealed cab - no ports) like the 8x10 design may not be optimum for what you are looking for. No ports means a smoother sound usually, but it really soaks up power. 18 drivers usually are designed for a bass reflex (ported) design cabinet to get the optimum performance and output. I would read up on the drivers you intend to buy / use, and see what the manufacturer suggests (usually their own design cabinet or endorsed design). Years back I had Altel Sound in Bridgeport CT make me a pair of custom design cabinets using 1 each K151 JBL 18 driver in a bass reflex design, and I still have them today. They had a computer program that would calculate the perfect port volume for a given cabinet volume, and could even tune the port to a specific frequency that would work for the speaker and your application. They are most comparable to an SWR BigBen cab. Easier to move than a 2x18 cab too. Try googling speaker cabinet design, or Theale bass reflex design (spl?) or JBL or EV, etc. There are decades of research into most cabinet designs, and it should be available on the web.  
Good Luck
Kris

[cozmik_cowboy]

Long, long ago, when I was doing equipment/monitors for Vanessa Davis Band, I helped the bass player (Gary Krolak - amazingly tight and swinging groove player with the added ability, if seldom the inclination, to do very tasty outside stuff) revamp his rig, fretboard to speakers.  One of the things we did was have the great Ed Reynolds (then of Soundsmiths in Chicago, now DBA Ed Reynolds Guitars in Austin) rebuild one of his SVT 8X10 cabs so the middle 4 10s were replaced with a 15.  Tri-amped with a single 18, it sounded amazing, but while Ed was initially excited by the challenge, I believe he would shoot anyone who asked him to do it again.  Sell the Ampeg, buy a purpose-built cab.  Easier &, probably, cheaper.
 
Peter

[bigredbass]

Buy a pair of EDEN single 18 bins, I can't think of a better box for those earthmoving implements.
Usually, in a world gone mad for 10's, the dealers will welcome you with open arms!
 
J o e y

[bassman10096]

Two single 18's are definitely easier to manage than a 218 cab.  Also, gives you the optionto take only one 18 to a smaller gig.  
The surgery it would take to convert an Ampeg 810 for use with other drivers would be significant and may not produce a good result when all's said and done.  Better to avoid messing up a perfectly good 810, sell it and buy what you really want.

[matthew90046]

Are we talking about a working cab or one that is a total loss?  To me this would be an important decision making factor.

[terryc]

My little bitsworth...having built cabs for myself and others I agree with the majority and sell your existing cab and buy the purpose built ones.
It is rewarding to build your own but you have to get the volumetric calculations correct to get the best out of the chosen speaker taking into consideration its performance specs(frequency cutoff, thresholds, attenuation,design etc)
You also need the correct tools to build the cab as well, taking your time in as well as purchasing all the materials, the drivers, coverings, cabinet hardware, fixings, tools and maybe a contructors manual it may be more cost effective to buy one. But good luck whichever way you decide to go