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    Folded horn versus sealed enclosure

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    Brap

    Posts : 83
    Join date : 2013-11-28
    Age : 60
    Location : Lisle, Illinois

    Folded horn versus sealed enclosure

    Post by Brap on Fri Apr 04, 2014 2:06 pm

    Contemplating a speaker project -- folded horn with Lowther PM5 SDFR or a enclosed vented with a Seas Exotic DR driver. Of course, the ST-70 would be the source. Who has experience in this area??

    anbitet66

    Posts : 131
    Join date : 2009-12-23
    Location : Valley Stream, NY

    Re: Folded horn versus sealed enclosure

    Post by anbitet66 on Fri Apr 04, 2014 6:33 pm

    I have no experience with it, but I know of plans to make one from a single sheet of plywood:

    http://www.audiocircle.com/index.php?topic=83392.0

    I've had that article for years but lack the necessary skills to build one.  Anyone feel lucky and possess the needed skills and one sheet of ply?

    Tube Nube

    Posts : 603
    Join date : 2008-12-06
    Age : 53
    Location : Calgary, AB

    Re: Folded horn versus sealed enclosure

    Post by Tube Nube on Sat Apr 05, 2014 9:42 pm

    A very simple-to-build horn speaker is the fh-3 (frugal horn -3). If you search that out you'll find plans, and also forum support on DIY audio.

    My own sealed box experience was my Linn Indes IIs with my st-70. Sounded fine. Good, to be sure. They retailed for about $600 when I bought them. For just under $600 I built a pair of folded horn, single driver full rangers. No comparison. A staggering difference.

    Tube Nube

    Posts : 603
    Join date : 2008-12-06
    Age : 53
    Location : Calgary, AB

    Re: Folded horn versus sealed enclosure

    Post by Tube Nube on Sat Apr 05, 2014 9:46 pm

    Sorry, your question was more specific than that. I hope you'll keep us informed about your choices and results.

    baddog1946

    Posts : 304
    Join date : 2010-02-03
    Location : Costa Rica

    Re: Folded horn versus sealed enclosure

    Post by baddog1946 on Wed Apr 09, 2014 11:10 am

    I have been using two types of open box formats and both sound IMHO superior to my sealed boxes speakers (KEF 100 and Advents) both open box types are from the mind of Steve Deckert.
    The NFX a variation of the Jensen ultra flex design and the DNA is a rear loaded horn design. The NFX uses Fostex 206en (SPL99db) and the DNA using both Fostex : FE163EN-S and Alpair 12P's.
    The NFX's have amazing bass response as the design unloads immediately through the large vents on the sides. The DNA's with either drivers are more detailed and sound a bit tighter in all areas. In any case both boxes and all the drivers offer superior acoutics IMHO especially in triode mode than the  sealed box thumpers.
    I think my tubers (ST-120 and ST-70) in triode offer a very compatible signal to these Full rangers and are what I listen to all the time now. One can never forget that what we hear is subjective and is affected by all the components in your system;s topology.

    Brap

    Posts : 83
    Join date : 2013-11-28
    Age : 60
    Location : Lisle, Illinois

    Folded horn versus sealed enclosure

    Post by Brap on Fri Apr 11, 2014 10:59 am

    Thanks for your comments and suggestions! I have decided to give a gift to my sister for her 65th. It will be the Madisound BK-12's I am staining now with the Fostex SDFR's that came with the kit. I have a GLOW 5 watt SET that will go with those. This means I now needs to make something for myself. Thinking about the Fidelio cabinet with Lowther DX3 SDFR. Initially, I will try the ST-70 but also have a 12 watt PP I built years ago. Ultimately, may keep the ST-70 for my Paradigm Studio 10's V5 that really work well together and may think about OTL topology for the Fidelios. Just dreaming now though -- need to save some pennies. Will be going to Axpona here in Chi-Town in 2 weeks to do more research.

    tubes4hifi
    Admin

    Posts : 1261
    Join date : 2008-11-30

    Re: Folded horn versus sealed enclosure

    Post by tubes4hifi on Fri Apr 11, 2014 8:40 pm

    another consideration is that a folded horn enclosure is likely to have an efficiency (or sensitivity) of around 100db/w,
    compared with a sealed box design that is going to be around 85-88db/w, so for a folded horn speaker you'll need 1/20 the power
    that you would need for a sealed box. That's why 5w amps are popular with that crowd, and the rest of us like 100w amps.

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