$3500 Speakers for $350? Klipsch KL-650 Clones
The Klipsch KL-650 THX were iconic in the Home Theater Industry. It was one of the first times I remember that you could affordably buy speakers that were truly designed for a small movie theater, for your own home theater. However, when I say affordably, they still cost around $$3500 for a pair(currently a little cheaper on Amazon)! And for the entire system..a cool $13,000! And although, for movie theater speakers, that isn't crazy, it is still a lot more than I want to spend on my Home Theater. And truthfully, I think that is the same as most other people.
That is where I got the idea to clone them. Interestingly enough, Parts Express actually sells the exact horn that those speakers used. I thought about using it, but I decided not to for two reasons. The first, it's on buyout, so once they are gone, no one else can build the speakers. The second, others that used them, really weren't impressed with them. It is possible they needed a better design for them. But it is also possible that these were B stock and had some inconsistencies in the production. Others have told me this is what they suspect. So I decided, I would clone them as close to the original as possible. Try to make it as good or better, for under $200 a speaker. *update: I missed my goal. Each speaker comes in right around $200. However, if you get yourself some coupons or sales, you could get it for less.
A little background about the speaker. Since this is a THX speaker, it is designed to be crossed over by 80hz. It also should be highly efficient and not need much to push it. It also should have a +-3db response and as flat of a response as possible.
17" wide x 15" tall x 12.5" deep
Response: 56hz-20khz (+-3)
Sensitivity: 92Db according to Sound and Vision
Horn Dispersion: 90 degree x 60 degree horn
Impedance: Nominal 8ohm
Drivers: two 6.5" and 1" compression tweeter
max power 150w
Parts for the Clone:
For the parts, I wanted to get as close to the original specs. I choose the JBL (selenium) compression driver, as it had excellent efficiency, a very flat response and is known as one of the better compression drivers you can get on a budget. But I needed to pair that with a good waveguide. Since I don't want anything that can have that pinched sound and the H6512 promised to deliver a smoother HiFi sound that I was going for. I still need to find some mids. I knew I wanted them to be either 16ohm or 4 ohm. That way I could obtain a nominal 8ohm load. I also wanted something flat, efficient and could go down to at least 70hz for a good 80hz crossover integration. The FaitalPro checked all those boxes.
(1) JBL D220Ti
With these parts I was able to come very close to the original specs of the Klipsch. And I was able to hit all of the design goals.
17" wide x 16" tall x 12.5" deep
Response: 58hz-20khz (+-3)
Sensitivity: TBD guestimate around 95db
Horn Dispersion: 90 degree x 50 degree horn
Impedance: Nominal 8ohm
Drivers: *two 6.5" and 1" compression tweeter
Max power 140w
*Although the Faital Pro are listed as 6" drivers, a nominal driver size is based off its outside frame diameter. I know, and yes it is silly. Having said that, the FaitalPro's are 6.59" outside, making them a nominal 6.5" driver. In fact, it is about 1/4" bigger than the original drivers.
As you can see, they are almost identical to the original Klipsch. The height, is 1" bigger, but almost everything else is identical. Take for example the mids.
I decided to port tune the FaitalPro's to 68hz, which gave me an F3 of right around 58hz. Which is right on par with the original.
I did a very conservative port size. The tuning/size shouldn't have any audible port noise even up to it's rated maximum power up to it's rated max of 140w.
Although, it's maximum power is a little less, it wouldn't make really any difference in final SPL. In fact, if this is indeed more sensitive, it will get louder than the original. Either speaker at it's max though, should be entirely too loud for a private home theater.
Due to the Pandemic I thought it would be best if I gave these plans away for free for the time being. Since it is free, it's not as detailed as some of my other plans. Please share the video. Also feel free to ask questions on anything that isn't clear. We'd be happy to help out. I definitely hope some of you build these.
The box itself will use 3/4" material. I used MDF, which is about $30 a sheet at your local hardware store. You should be able to make at least two speakers out of one sheet. The speaker dimensions are 17" wide by 16" tall and 12.5" deep.
Each speaker you want to build will use these components. If you want to build 2 speakers double it and 3 triple it.
(1) JBL D220Ti
(1) 4 ohm resistor
(1) 2 ohm resistor
(1) 1.5 uf capacitor
(1) 6.8 uf capacitor
(1) 7.5 uf capacitor
(1) 12 uf capacitor
(1) 3 mH inductor
(1) 0.75 mH inductor
(1) 0.22 mH inductor
(1) Terminal Cup
(1) spray glue
(2) acoustic foam
(1) wood glue
Sample Cut List
Not everyone has a nice shop where they can cut everything out on. So here is an idea of a cut list that would work. You can easily input these into a free program like this. which will help you cut it from a sheet of mdf. The benefit of cutting it this way, is the sides and the brace will all be cut the same size, which will be helpful in assembly of the cabinet. Each speaker will need this cut out.
(2) Front and Rear baffle: 17" x 16"
(3) Sides and Brace: 11" x 14.5"
(2) Top and Bottom 17" x 11"
*there will be a port cut later. This can be any material even your scrap 3/4" material
Here is a sample of the pieces being cut for two speakers from one sheet of MDF (MDF is typically 97" x 49") which is what I input. If yours is smaller, you will need to adjust for that.
The brace is listed as 11" by 14.5." This will go in-between the faital pro drivers and the waveguide. This is typically used to work as both as a brace and one side of the port. If you do that, you will want to leave the bottom corner by the port to be solid. I also cut out a portion of the back so that I can center the terminal cup. You do not have to do this, your terminal cup will need to be off-center in the back, as the brace will get in the way. In my opinion, it is easier to work on the speaker with this portion cut out. Here is an example of a brace with a 3" square left to use as the side of the port and the rear cut out. All sides are 3/4". Feel free to make your brace however you like.
The port is 2" tall and 6.5" wide and should be about 1.5" long. Since the front baffle is made from 3/4" material, we will want to extend the port an additional 3/4". That means depending on how you will need a piece of material extending 3/4" further into the box. The size of this piece will depend on how you built the box. But I will assume you are building the front baffle exactly like mine and will be using the brace as a side of the port. If you are, then you will need to cut a piece of material 3/4" by 7.25". The reason you will need to cut it 3/4" bigger, is due to the fact that centering the port on the tweeter, will leave about a 3/4" gap, which we will need to put some scrap 3/4" material in that gap to make it up. That piece can be of any length, but should not be any taller than 2". Make sure it does not impede the port. Remember, this was not in the cut list, so this is a piece you will need to cut now. Typically a big box store will not cut a piece this small.
The front baffle should dictate whether you are building a right or left speaker. The one pictured is a right speaker. A left would be the mirror image of this. The center channel can be either a right or left. The center point of the Faital Pro drivers is 4 1/2" from the side and 4 3/8" down from the top or 4 3/8" from the bottom respectively. The port cut out is 2" tall starting 3/4" up. This allows you to use the bottom of the box as part of the port. It is 6.5" wide and should line up with the waveguide directly above it.
The Faital pro drivers will be wired in series. This will get you a nominal 8ohm load. Also pay attention, the tweeter polarity is reversed. What does that mean? If means you hook the ground from the crossover to the positive terminal (red) of the tweeter and hook up the positive wire to the negative terminal (black).
If you are not familiar with crossovers, I would suggest keeping the tweeter and woofer circuits separate.
*I may change the crossover to a 3rd order on the woofers. This has little affect to the response, but will get rid of the tank cap. If I do this, I will update this page.
Visual of what the circuit could look like. Note I reversed the polarity on the circuit so you would hook up the wires exactly as written.
*I used a Mills 4ohm resistor (maroon). That's just what I had on hand. The plans use a 4 ohm white Dayton resistor. Your resistor will be white.
Always lay everything out and test fit it before you glue everything. If you really want these to sound their best, I would recommend using some sound absorption material in the cabinet. Use some spray glue to keep it in place and keep it away from the port.
*These Build Plans are free for Personal use. Contact for more information about commercial use or resale.
I love it when a DIY clone is 1/10th the original price. I assume you would still use a subwoofer for below 70hz.
Also THX is and is probably meant to be a mystery. Besides that crossover point you mention, what else is it? I had a Logitech Z623 with THX which is a small 2.1 setup with a 6.5" sub and two c. 3" wide range satelites. Great bang for buck for students and people on a budget. Appreciate your knowledge about this stuff.
Very nice project! What about the crossover design? Any tips for crossover?
Also THX is and is probably meant to be a mystery. ....
I was listening to a Daily HiFi clip with the guy from Monolith, and he said that they had one of their subs in for THX certification and he was told it wouldn't pass. He asked what needed to be done to get it certified and they wouldn't tell him.
C'est la vie.
Very nice build and design! Do you have any plans for the finish? I bet some wood fineer on the front baffle and the rest in black thinned duratex will look amazing with these drivers :).
@tvor-ceasar It looks like if you're a "partner" you can learn how to get some feedback on the tests https://www.thx.com/blog/claridy-audio-outlaw/ I wouldn't be surprised if it takes paid engagements or min spend or some buy in process, but it would seem that it is possible to see some inputs to help get a system to pass.
I did finish them and the video will be out by Tuesday. I wanted to get it out tomorrow, but I don't think that will happen. I will update the thread when I have it finished along with the plans. I am thinking for the time being, with so many struggling with COVID-19, it might be a nice way to give back by offering the plans for free.
It is not a fullrange speaker and is designed to use the THX standard by crossing over by 80hz. Although, when I ran Audyssey it actually crossed them over at 60hz. After listening to it, I feel the 80hz crossover is a better.
I will have the crossover design out later this week. Free for the time being. Hopefully give some people a project to do during the Pandemic. It also will help with the cost. These are significantly cheaper to build I still need to figure out the exact cost.
That's awesome and thank you for sharing this. I will give tons of fun for lock down for sure! (in Chile we are still in lock down).
¿How would be the performance of this spkeakers for music / hifi ? (It's clear form me that these are suitable fot home theater)
They are very clear, which is a good thing. For music they are fine. Just keep in mind they are designed flat, so some people for music, might EQ them for their music tastes. Also, these are designed to be crossed over around 80hz, so there isn't much in terms of bass. That is due to the fact these are designed for a THX theater in mind. So they will be handling everything from 80hz on up, with your subwoofer handling the bass.
How about some 15's? Sneak peak at a not even close to finished project.
@123toid Yes, more please, I like!! Also nice work on sharing the build plans!!
And, was the mustard the secret to the sound?