Sealing Ports

wesarvin · #1 07-23-2010, 05:51 PM

First post!

I have a 610hlf cab and I'm curious if it's possible to convert it into an infinite baffle design. Any advice, help, etc. would be greatly appreciated. Thanks!

johnk_10 · #2 07-23-2010, 05:59 PM

the speaker in the 610HLF were designed for use in a ported cab, so i wouldn't recommend it. IME, you get just about the same effect if you cut everything below 40-45Hz at about -10db with it.

wesarvin · #3 07-23-2010, 06:05 PM

I thought that they were the same drivers that were in the 810s.

johnk_10 · #4 07-23-2010, 06:08 PM

nope.

jarrod cunningham · #5 07-23-2010, 06:19 PM

Ports are there for a reason . Your cab will not sound better .

muddycreek · #6 07-23-2010, 06:34 PM

But you can shove some foam in there to try.

Mr. Foxen · #7 07-23-2010, 06:52 PM

Plug them up, see if you like it. It is very likely whatever you jam in the ports will shoot out or suck in though. If there is multiple ports, I think blocking them will lower the cab tuning, so lows wills tart rolling off earlier, and the port airspeed will increase, so it might start chuffing earlier. Might be wrong on those, but let me know what happens when you try.

wesarvin · #8 07-23-2010, 06:55 PM

Interesting. Can somebody explain the theory to this? I thought that sealed designs were much more simple, and that the increased damping factor lessened the need for scrutinizing over port theory.

For clarification, I mean sealing each row of 10s, not simply stuffing the ports in the bottom.

One would think that by sealing the internal ports in each row of speakers, one could create a smaller version of an 810. I'd love to hear from some cab designers on this issue. Forgive my scrutiny, but I'm a longtime lurker and first time poster.

johnk_10 · #9 07-23-2010, 06:57 PM

i guess the first question should be, why do you want to block the ports?

wesarvin · #10 07-23-2010, 06:59 PM

To tighten it up a bit, sorta like an 810e or 410he, but middle-ground in terms of size. The sound is good, but I guess it's more of a feel thing from the playing end.

johnk_10 · #11 07-23-2010, 07:03 PM

i've owned the 410HLF, the 610HLF and currently have an 810AV. i think that the 610HLF is a little closer sounding to the 810, but i didn't care for the tweeter in it. i used to make it 'tighter' by just cutting some subs with eq.

Mr. Foxen · #12 07-23-2010, 07:14 PM

The difference is the type of speaker. Some are suited to sealed cabs, and some to ported.

wesarvin · #13 07-23-2010, 07:22 PM

Would you happen to know the different specs of the speaker used in the Ampeg 810 and 610hlf, respectively? I understand that cone excursion and Thiele-Small parameters affect the design of a ported box, but I thought that for a sealed box, it doesn't matter nearly as much.

johnk_10 · #14 07-23-2010, 07:58 PM

since it's an OEM speaker, it's difficult to find all the specs for it, but i believe that the sealed ones used in the 810E are vented thru the front of the dome. the others are rear vented on the magnet.

here's the SVT610HLF speaker (it's 6 ohms):
http://www.speakerrepair.com/mm5/mer...Category_Code=

here's the 410HLF (4 ohm) speaker:
http://www.speakerrepair.com/mm5/mer...Category_Code=

and here's the 810E speaker (32 ohm):
http://www.speakerrepair.com/mm5/mer...Category_Code=

billfitzmaurice · #15 07-23-2010, 08:06 PM

Quote:

Originally Posted by wesarvin

I understand that cone excursion and Thiele-Small parameters affect the design of a ported box, but I thought that for a sealed box, it doesn't matter nearly as much.

It matters just as much. If you want the sound of a sealed cab buy a sealed cab.

wesarvin · #16 07-23-2010, 09:17 PM

Thanks guys. So now that we've established the absurdity of modifying that cab, what would the feasibility be of actually carrying through? I was thinking just use 6 ohm eminence drivers and blocking all ports, internal and external. Does this sound crazy?

I'm asking because I got the hlf for a great deal but don't want the size of a fridge or expense of a Bergantino.

jarrod cunningham · #17 07-23-2010, 09:38 PM

so basically you wanna cut out the front baffle and put in dividers like in a 810e and then replace with a new front baffle with no ports and replace the speakers ? still seems like you should sell the 610 as is , and build your own sealed 610 to a 3/4 scale of a 810e . i personally think thats the way to go .

wesarvin · #18 07-23-2010, 10:25 PM

I also think that building a new cab is a good idea, but...

Have you seen the inside of a 610hlf? It already has dividers inside on each row, albeit with 6in ports on each side. I would think one could fashion a plug to fit inside the speaker opening to seal the internal baffles.

Bass_Pounder · #19 07-24-2010, 10:25 AM

Quote:

Originally Posted by wesarvin

I also think that building a new cab is a good idea, but...

Have you seen the inside of a 610hlf? It already has dividers inside on each row, albeit with 6in ports on each side. I would think one could fashion a plug to fit inside the speaker opening to seal the internal baffles.

If the internals are similar to the sealed cab (except for the porting), then you probably could do a re-work.

However, even though you got the cab at a great price, have you priced the cost of 6 new drivers yet ?

You may find that the cost of the new drivers + the cost you paid for the 6X10 may end up costing more then just selling the cab as is and buying the right one.

Bob Lee (QSC) · #20 07-24-2010, 12:44 PM

If you're really set on doing that, go ahead; no one's going to stop you.

Maybe it'll happen to work out to your liking. But also be prepared to discover that it might not have been a good idea.

While you experiment I would suggest not making any modifications that you can't undo or reverse.