Thinking of some more Klf-20 Modifications

[Fizik]

I have a pair of KLF-20's as my front mains. I really enjoy them and have already upgraded to the crites titanium tweeter and upgraded the crossover components as well.

The cabinets aren't bad, don't rattle etc, but I'm probably going to rebuild them with in black walnut to match the rest of the furniture I've built in my living room.

 

As part of that process, I'm considering replacing the KLF-20 drivers with RF-7i/ii drivers as I miss the copper look my RF-5's had. Plus I think a three way speaker with copper drivers would look awesome. I haven't seen much on the differences in specs for the drivers and if that would work or not. Maybe someone here knows.

 

If I keep the stock drivers, I'll build the cabinets to the same specs and reuse the front and rear boards. If I go with the rf-7 drivers I'll probably make the cabinets slightly taller and and make a new motor board for the front so the drivers fit properly.

I've been keeping an eye out for 4 rf-7 drivers preferable used since paying over $650 for new ones isn't really in the budget. So if anyone has/ see's them or has a good deal on new ones I may be interested.

 

Thoughts, comments and suggestions are welcome. Especially since I haven't started it yet and its open to change.

[dtr20]

That wood look pretty cool, I would love to see it. However, I think it should drastically change the sound, maybe worse, maybe better. Keep us up to date with what you do. I'm sure others can come in about the woofer specs.

[Fizik]

1 hour ago, dtr20 said:

That wood look pretty cool, I would love to see it. However, I think it should drastically change the sound, maybe worse, maybe better. Keep us up to date with what you do. I'm sure others can come in about the woofer specs.

It'll still have an MDF core, so it shouldn't change the sound drastically unless I give them more volume inside.

[pzannucci]

15 hours ago, Fizik said:

It'll still have an MDF core, so it shouldn't change the sound drastically unless I give them more volume inside.

Fizik,

Where did you get that information?  Unfortunately you are incorrect unless the RF7 woofer is an identical match for the 1036 in the KLF20, which I very much doubt..  

If you swap the woofers it will definitely change the sound.  The porting may need to be changed and the crossover to accommodate the changes in efficiency, response, and impedance of the RF7 woofers.

None the less, it would be a great project if you have the tools and the ear to do the crossover work from a looks perspective.

 

BIG BIG Caveat: The klf20 woofers are very good (maybe better than the RF7) and can sing better with a little more air in the box.

[Fizik]

2 hours ago, pzannucci said:

Fizik,

Where did you get that information?  Unfortunately you are incorrect unless the RF7 woofer is an identical match for the 1036 in the KLF20, which I very much doubt..  

If you swap the woofers it will definitely change the sound.  The porting may need to be changed and the crossover to accommodate the changes in efficiency, response, and impedance of the RF7 woofers.

None the less, it would be a great project if you have the tools and the ear to do the crossover work from a looks perspective.

 

BIG BIG Caveat: The klf20 woofers are very good (maybe better than the RF7) and can sing better with a little more air in the box.

I meant changing the exterior of the box shouldn't change the sound (even though the material is slightly different than what Klipsch used to build them) much unless I make them larger. I have no idea how changing the woofers will change the sound. Part of the reason for starting the thread. Also thank you for the comment on the woofer quality, exactly the type of info I'm looking for.

[pzannucci]

Fizik,

 

Sorry for the confusion.  I didn't realize you would be using real solid wood.   Most folks veneer.

 

If you have something like woofer tester from Parts Express, you can probably do a pretty good job though the crossover will need rework.

 

As far as the cabinet, if you stay with the klf woofers, open the cabinets up to 4.5-5 cubic foot tuned to around 30-34 hz.  It will make quite a difference.

 

If you are using real Walnut (very very nice oiled), put a layer of 1/2 MDF on the inside with a more rubberized glue between them.  That would work excellent with the expanded size.

 

Post progress if you jump into this project.

 

 

[Fizik]

Still interested in more info on the driver comparisons.

[pzannucci]

Fizik,

If you are going to use the RF7 not RF7 II woofer, look up the discussion for deang's network changes.  I believe there is a peak in that woofer that may need to be dealt with.  Do you have any equipment to test the woofers for a crossover change?  If not you may want to see if someone can give you impedance plots of both woofers.

[Fizik]

3 hours ago, pzannucci said:

Fizik,

If you are going to use the RF7 not RF7 II woofer, look up the discussion for deang's network changes.  I believe there is a peak in that woofer that may need to be dealt with.  Do you have any equipment to test the woofers for a crossover change?  If not you may want to see if someone can give you impedance plots of both woofers.

I'm thinking I'd go with the 7ii drivers are they are a bit easier to find. Finding 4 undamaged first generations drivers I believe would prove difficult.