Frugal Horn Mk3

[Toppsy]

Thought I'd post up a couple pictures of my latest build.

These are the Planet10 http://www.planet10-hifi.com/ offering of the Frugal Horn Mk3 designed by Scott Lindgren (Scottmoose of Woden Designs http://www.wodendesign.com/

The design is featured here http://www.diyaudio.com/forums/full-...ta-builds.html should anyone be interested.

The speakers have been designed to be quite flexible regards different 3" and 4" FR drivers. The ones I've build feature the Mark Audio paper coned CHP70 drivers.

For those wanting a small floorstander with bags of WAF that also sound stonkingly good I can highly recommend these.

[Richard]

Beautiful job there Colin

[Edwin]

Hear! Hear!

[BOONDI]

You have some amazing woodwork there Colin......

Deeply impresed.....

[Toppsy]

Thanks for the compliments guys, much appreciated.

I have made a slight cosmetic change to the speakers. I have added some outrigger style spiked feet. 1) To improove stability - these speakers are only 7" wide. and 2) To replace the wooden blocks that they were supported on.

I have a suspended timber floor with heavy woollen carpet that can cause booming to floorstanding speakers. These being rear ported with the horn exit being low to the floor benefit with raising them on spikes. This had had the desired effect.

[Edwin]

Toppsy

I see from your photos that the speakers are placed well away from the wall - at least 12". On the FrugelHorn website, they show an alternative of having the speaker in a corner backing onto a wedge-shaped diffuser (which also positions it away from the walls). That arrangement would depend on how far apart the corners were and would probably be suitable only for fairly small rooms, I imagine. Is this a "problem" with all folded horn speakers - that the placing of them may be difficult. In your room, the chimney breast provides a good solution.

[Toppsy]

Edwin,

I think you are referring to the original Mk1 Frugal horn that was designed specific for the Fostex FE126e, and was designed for corner loading. The rear vertical wedge was part of the upgrade path for that particular design along with a suprabaffle. It is not a general rule for folded horn designs.

The version here is the Mk3 (though to my knowledge there is no Mk2) and was designed to be an easier build and a far more forgiving load for different 3" and 4" FR drivers.

The Mark Audio CHR70, Alpair7 and CHP70 are designed to give good bass lift without need of a BSC (baffle step correction circuit) and do not require to be corner loaded to achieve deep quality bass. In fact they are around 15" off the back wall and yes the recess of the firesurround will help. However they are equally happy on a straight wall placed 12" - 15" off the rear wall. They do require some extra damping just below the driver over the Fostex drivers (FE126e, FE126En and FE127e) of which I understand benefit from corner loading and do not require the extra damping below the driver as they don't have the same bass lift the Mark Audio drivers have.

For a smallish room (mine is 5m x 4m with large bay window) these can excel and fill the room with sound with more than enough loudness. However, the MA drivers being less efficient than the Fostex do require a more powerful amp. I run these with a 300b SET and much better with a GM70 SET. But having said that they are happy with simple solo femal with acustic guitar type music on a flea 6EM7 Se amp that produces no more than 1½W.

In the build is a FE126 version of this speaker.

[BOONDI]

OUTRIGERS!!!!

Brilliant idea......

Seems to me to be exactly what's needed in my situation at home to calm my floor shaking bass.......

[andrew ivimey]

NOpe - outriggers are best left to those in polynesia. Frug3s are just right as they are - let the four inches take the strain.

[Toppsy]

Andrew,

Your comments regards not using outriggers on the FH3 speakers is only in relation to the Fostex FE126En version this speaker; which with a Xmax of only 0.35mm cannot produce any bass of any meaning.

With this driver they do benefit greatly with being directly coupled to the floor to give them the much needed bass lift that the driver is incapable of producing without. The FE126En also requires corner loading for the same reasons. This is how you have them located in your home and also on a solid tiled floor. That's the only reason the FH3 with the fostex are giving you any decent bass.

Now with ALL the Mark Audio 4" drivers (CHR70, CHP70 and Alpair7) they have a bass lift built into the driver to counter baffle step correction that can and does reduce bass output and so these drivers do produce far better bass performance and will sound over bass if not decoupled from the floor. Especially if one has a carpeted suspended timber floor.

Afterall tScott did optimise the design the FH3 for the Mark Audio drivers and having now heard and built all 4 versions (FE126En, CHR70, CHP70 and A7) the MA versions are all superior in performance to the fostex. And the (apart from the Fosex) all benefit from decoupling from the floor whether using ouriggers are any other preferred means. The additional benefit the outriggers is to give greater satbility to these rather narrow speakers.

But I'm glad you are happy with your FH3's. Compromised, as they are, by the too thin MDF construction and FE126En driver.