AdministratorAugust 17, 2020 at 11:58 pm
V2 is Here:
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 design a speaker similar to 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 use design goals to design 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 This Build:
For the parts, I wanted to get as close to the original specs as I could. 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 my 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, I did pretty good picking out components that would get me similar results. The height, is 1″ taller, but almost everything else is right on spec. 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.
MemberAugust 28, 2020 at 3:25 am
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.
MemberSeptember 10, 2020 at 1:12 pm
Very nice project! What about the crossover design? Any tips for crossover?
ModeratorSeptember 10, 2020 at 3:07 pmPosted by: @pwarren3030
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.
MemberSeptember 12, 2020 at 6:27 pm
@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.
AdministratorSeptember 12, 2020 at 8:41 pm
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.
AdministratorSeptember 12, 2020 at 8:43 pm
AdministratorSeptember 12, 2020 at 8:45 pm
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.
MemberSeptember 13, 2020 at 12:24 pm
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)
AdministratorSeptember 14, 2020 at 9:38 pm
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.