It's cold and snowing in Brooklyn, NY, a great opportunity to start a new thread.
I recently built these Telefunken OB speakers inspired by Kevin @ glowinthedarkaudio.com. I think it's extremely kind of him to be sharing his knowledge and experiences. Inshort Kevin helped save me time and money. I just recently started on this diy speaker hobby and new to woodworking, and the reason I choose these OB speakers is that I don't have access to computer programs that are needed to built closed or vented enclosures. I also wanted a challenge in woodworking instead of just using a broad as an OB.
I'm very happy and glad I built these OB's. I built mine to be flexible. The front panels are removable, incase if I want to do 2 or 3 drivers, or even an array of drivers. I also built 12 inch plates for smaller drivers that can be easily swapped. I used half inch plywood, if I built a second pair of these I would go with hardwood.
These OB are very forgiving, just about every speaker I have installed sounded great. Of course certain drivers sound better than others, but just about all of them displayed good imaging and separation between the high and low frequencies. The following are drivers I have used: Fostex FE208sigma, Fe168Esigma, Coral Holey Basket, Elac 8 inch, Akai 10 inch coaxial, Berman 12 inch guitar amp speakers. So far my favorites are the 2 Fostex and Coral's. I absolutely love them with my SS accupahse e202. I also played them on a brand new Decware SE84CKC. Maybe the Decware needs to time to breakin, but it's not sounding as dynamic as the accuphase. Haven't done any A/B speaker tests yet, will report back when I do. I'm curious to see if they sound better or more open then regular speakers, But my first impression is that the bass is not as tight or dynamic as boxed speakers. I'm not a bass junkie anyway, definitely enough bass for me.
Thanks for reading, would appreciate any advice.
I recently built these Telefunken OB speakers inspired by Kevin @ glowinthedarkaudio.com. I think it's extremely kind of him to be sharing his knowledge and experiences. Inshort Kevin helped save me time and money. I just recently started on this diy speaker hobby and new to woodworking, and the reason I choose these OB speakers is that I don't have access to computer programs that are needed to built closed or vented enclosures. I also wanted a challenge in woodworking instead of just using a broad as an OB.
I'm very happy and glad I built these OB's. I built mine to be flexible. The front panels are removable, incase if I want to do 2 or 3 drivers, or even an array of drivers. I also built 12 inch plates for smaller drivers that can be easily swapped. I used half inch plywood, if I built a second pair of these I would go with hardwood.
These OB are very forgiving, just about every speaker I have installed sounded great. Of course certain drivers sound better than others, but just about all of them displayed good imaging and separation between the high and low frequencies. The following are drivers I have used: Fostex FE208sigma, Fe168Esigma, Coral Holey Basket, Elac 8 inch, Akai 10 inch coaxial, Berman 12 inch guitar amp speakers. So far my favorites are the 2 Fostex and Coral's. I absolutely love them with my SS accupahse e202. I also played them on a brand new Decware SE84CKC. Maybe the Decware needs to time to breakin, but it's not sounding as dynamic as the accuphase. Haven't done any A/B speaker tests yet, will report back when I do. I'm curious to see if they sound better or more open then regular speakers, But my first impression is that the bass is not as tight or dynamic as boxed speakers. I'm not a bass junkie anyway, definitely enough bass for me.
Thanks for reading, would appreciate any advice.
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It's a very good desing, i have similar OBs and for some time i regret i haven't build it with removable front panel. I run them with Klangfilm L307s but i'm lazy to try older fe103 i have, even if i'm curious about the sound. Please keep sharing your opinions about the drivers in future, as well as optional methods of bass support. some drivers may do it alone nicely, though.
ps- i guess 'telefunken' is just a personal name for the project, but i'd love to see a photo or scan of the authentic drawing, i'd be surprised it really existed.
ps- i guess 'telefunken' is just a personal name for the project, but i'd love to see a photo or scan of the authentic drawing, i'd be surprised it really existed.
you can make a removable rear panel or various panels to tune the sound further. the 'real' OB should have nothing but the 1.5 - 2m space behind, then you get the 'OB essence' but there are many pseudo-OB speakers like Auditorium 23, Musical Affairs, Ocellia. OK, they are resonant constructions but i mean that rear / bottom porting, etc.
i'd like to build some sort a partial barrier for the back-wave bass energy while retain the OB airiness, not choking the mids and highs. The panel would have some pattern on inside and some holes, it's all about the testing.
i'm not a bass freak either. for many the OB bass support is a must, it's a personal preference of musical perception, much dependent on a genre, but if the recording (of a chamber music or acoustic jazz) is not really anemic, i enjoy not having any support and it's the most detailed and coherent sound i can imagine.
i'd like to build some sort a partial barrier for the back-wave bass energy while retain the OB airiness, not choking the mids and highs. The panel would have some pattern on inside and some holes, it's all about the testing.
i'm not a bass freak either. for many the OB bass support is a must, it's a personal preference of musical perception, much dependent on a genre, but if the recording (of a chamber music or acoustic jazz) is not really anemic, i enjoy not having any support and it's the most detailed and coherent sound i can imagine.
Telefunken is not a name or design I came up with. Kevin at glowinthedarkaudio.com have an original Telefunken OB speaker. I guessed the dimensions and made some modifications.
i know, i meant him
but it's the least important thing here. today i've held 103s and begun seriously think about making those rings and trying them .. i'm happy with these 9" siemens drivers but one has to keep trying things i guess.Hi Dave,
Your like the godfather of these Coral Hoely and other various versions. Do you have any experience with them as a line array, 4 speakers in OB? I'm going to try and report back. I guess I'll wire them series and parallel to make them 16 ohms, since the Corals are 8 ohms. Can you draw me a simple diagram on how to wire them or point me to a website that has good info? Thanks.
i know, i meant him
Sure if you are curious. The 103s are light, you can use card broad, doubled up and glued if you want.
If someone in the NYC area that have the famous tannoys and lowthers, I would love to hear them. Please contact me.
Only a pair in BD pipes. They were quite good. These are bipole-like. A bunch in an array willplay louder, but likely they will loose some of their goodness. But try it.
dave
Hi, What are the distinguished drivers? If they are not my fav, I probably won't keep them.
A quick update, I installed 4 Coral Holey's as an array in the open baffles. My amplification is a new Decware SE84CKC. First I hooked up 2 speakers in serial, the sound improved over the single driver setup. It played louder, improved sound stage and slightly better bass. Sounded richer and more effortless.
Next, the 4 Coral's in an array, wired serial and parallel. My first impression is that it sounded slightly richer and slightly more effortless than the 2 drivers. Definitely an improvement. All type of music sounded good. I'm glad I gave this a try, might be time to get some plywood...
Will compare these OB's to a Spendor LS3 on a solid state amp next.
The surrounds look good, as you know, besides the fabric, they have a plastic layer. Yes, the baffle is made of cardbroad. I used 2 sheets and elmer's glue to give it a little more strength. Just a quick test. For OB, is cardbroad much more inferior to plywood?
OB vs Spendor LS3/5A
So I finally got around doing the comparison between my OB with 4 Coral Holey's to a pair of Spendor LS3/5A. The speakers were hooked to a Accuphase e202. The LS3 are not as efficient as the Coral's, I had to use decibel app on my phone to make sure they are playing at the same loudness. After a few minutes of comparing, the winner is the LS3. The LS3 sounded more dynamic and detailed, especially in the bass....the bass are more defined than the OB. Anyone have suggestions on how to improve the bass of the OB?
The Coral Holey's have potential, I'm tempted to put 2 in a karlsonator.
So I finally got around doing the comparison between my OB with 4 Coral Holey's to a pair of Spendor LS3/5A. The speakers were hooked to a Accuphase e202. The LS3 are not as efficient as the Coral's, I had to use decibel app on my phone to make sure they are playing at the same loudness. After a few minutes of comparing, the winner is the LS3. The LS3 sounded more dynamic and detailed, especially in the bass....the bass are more defined than the OB. Anyone have suggestions on how to improve the bass of the OB?
The Coral Holey's have potential, I'm tempted to put 2 in a karlsonator.
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I also find my OB speaker bass to be less 'defined' than my commercial floorstanding PMC and B&W speakers which are Transmission Line and Bass Reflex respectively.
I also notice that my 150W solid state amp (TGM7) produces much tighter bass than my 0.65W single ended 'Yukon Gold' spud amplifier
I have read that this is a common observation about OB speakers. I have seen it described as OB being more 'natural'. So, it maybe a 'matter of taste' as to which you prefer. However, I have not heard an OB with a powerful set of woofers - there are some designs on the internet showing multiple drivers in 'W' frames and other arrangements ?