New poster here though I've been a lurker for years. So I apologize in advance for being a bit of a nitwit on some of this. I know enough to know I dont' know enough.
I ran into a very good deal on both KEF Q800DS and R800DS. I've incorporated a pair of them in my surround system as rear surrounds but I'd like to use the other drivers to make non-dipole speakers, similar to the KEF R8 speakers, and just use these as directional speakers vs the diffuse dipoles. I'd use these R8 style speakers as wall mounted not to set on top of speakers. I currently have KEF R300s, R200C, R800DS being used and trying to acquire/build proper "height" speakers for an Auro 3D setup.
However, after some research and testing I've come to find out that the drivers used in these units vary a bit from the LS50 and Q150s in that the MF/LF driver is 8ohm while the tweeter is 4ohm (nominally.) I read a post by the KEF guy (Jack something/ hyphenated name) where he talks about how they wired these dipoles. I can find it if someone is interested.
My question is, before I get to far, will I be able to build a crossover to make these work properly? I was hoping it'd be as simple as building a replica of the xover but it seems after some initial testing that I'm getting some volume reduction on the tweeter (due to the xover expecting 8ohm vs 4ohm?)
I'm very skilled with woodworking/manufacturing and have the proper tools to make quiet nice and sophisticated DIY speakers and crossovers but I very admittedly don't have the necessary knowledge. This project is meant to be an introductory course on my way to build a very nice/expensive pair of DIY towers.
As I'm looking around, and as with many DIY things, I understand it may be easier/cheaper to just buy a pair of on wall surround speakers, (as the required fidelity is very low as well,) but I'd like to give this a try, to a point. I guess I need to know if that point is going to be worth it?
Thanks in advance for the replies. Here's the pics of the drivers from the R800DS and Q800DS.
I ran into a very good deal on both KEF Q800DS and R800DS. I've incorporated a pair of them in my surround system as rear surrounds but I'd like to use the other drivers to make non-dipole speakers, similar to the KEF R8 speakers, and just use these as directional speakers vs the diffuse dipoles. I'd use these R8 style speakers as wall mounted not to set on top of speakers. I currently have KEF R300s, R200C, R800DS being used and trying to acquire/build proper "height" speakers for an Auro 3D setup.
However, after some research and testing I've come to find out that the drivers used in these units vary a bit from the LS50 and Q150s in that the MF/LF driver is 8ohm while the tweeter is 4ohm (nominally.) I read a post by the KEF guy (Jack something/ hyphenated name) where he talks about how they wired these dipoles. I can find it if someone is interested.
My question is, before I get to far, will I be able to build a crossover to make these work properly? I was hoping it'd be as simple as building a replica of the xover but it seems after some initial testing that I'm getting some volume reduction on the tweeter (due to the xover expecting 8ohm vs 4ohm?)
I'm very skilled with woodworking/manufacturing and have the proper tools to make quiet nice and sophisticated DIY speakers and crossovers but I very admittedly don't have the necessary knowledge. This project is meant to be an introductory course on my way to build a very nice/expensive pair of DIY towers.
As I'm looking around, and as with many DIY things, I understand it may be easier/cheaper to just buy a pair of on wall surround speakers, (as the required fidelity is very low as well,) but I'd like to give this a try, to a point. I guess I need to know if that point is going to be worth it?
Thanks in advance for the replies. Here's the pics of the drivers from the R800DS and Q800DS.
Attachments
I should include the driver numbers for anyone searching in the future.
From the KEF Q800DS the label says SP1593.2 5" UNI-Q 8 OHM.
From the KEF R800DS the label says SP1639 - it does not give an impedance number.
I was betting on the fact the only difference between these and the driver from the KEF Q150 and KEF Q100s is the 4ohm vs 8ohm tweeters....but there may be more differences. I would like to know if any of you guys know as well.
I'd also like to use a pair of these to build a set of Q150 like speakers for my son, but waiting to see if I can design a xover to even make that work.
From the KEF Q800DS the label says SP1593.2 5" UNI-Q 8 OHM.
From the KEF R800DS the label says SP1639 - it does not give an impedance number.
I was betting on the fact the only difference between these and the driver from the KEF Q150 and KEF Q100s is the 4ohm vs 8ohm tweeters....but there may be more differences. I would like to know if any of you guys know as well.
I'd also like to use a pair of these to build a set of Q150 like speakers for my son, but waiting to see if I can design a xover to even make that work.
There is no need to fret over the relative nominal impedances of the woofer and tweeter as their actual measured impedances vary widely with frequency.
The Q150 and Q100 speakers have very simple crossovers and I suggest you simply follow their lead.
The crossover for the Q100 consists of a 0.68 mH inductor in series with the mid/woofer section and a 3.9 uF capacitor and 0.68 ohm resistor in series with the treble section.
Note that the tweeter must be wired in reverse electrical polarity to the mid/woofer.
If you require additional assistance, please ask.
