The Frugel-Horn Project

[chrisb]

Originally posted by stelleg151
Chris - thanks for the reply, much faster and more informative than expected.

The reason I have been pushing for the fe126's over the 127s is because I wont have more than 10w really. (SI) The 127's would probably be loud enough, but I would like as much headroom(efficiency) as possible.

As for the comparison between the Fostex recommended design and the frugels, I was just curious which you preferred, disregarding size.

I havent ruled out 127 folded (far from it), Im just hoping for a more efficient (louder!) alternative, thus my interest in the 126's. How would you (either of you) compare the frugals to the folded monopole 127 design? I realize they are very different speakers, but might as well ask anyways.

Just out of curiosity, when you coupled with the sub, was the HP filter passive? Also where did you do crossover? Sorry if I sound like Im nagging, Im just hoping for a HT system that can play music without being too fatuiging. Perhaps I hope for too much.

Thanks guys, sorry to sound like a broken record but you're awesome.

Whew, way too many forums discussing the same subjects - it's hard to remember who said what, where.

By "SI", I assume you mean Sonic Impact? While my preference for hollowstate amplification is well known, unless you're trying for rockconcert or movie theatre SP levels, 10watts or so of any kind of decent power should be quite adequate for the 126E's in most any enclosure, while retaining reasonable dynamic headroom.

If you've had a chance to collate the posts on the Frugelhorn project information scattered among at least 3 forums, you'll be aware that it's still at the early stages of evolution - very exciting and at the same time humbling for those involved.

Regardless of changes in details, the basic design concept will likely be maintained: a DIY open source design for compact BLH enclosure with rear mouth, and at least initially, adjustable CC to allow for driver experimentation.

For optimum performance even in systems that will incorporate separate woofers/subs, whether driven through passive XO, or fully actively, compact horns of this design family will need corner reinforcement.

With our brief session with the sub, we used the speaker outputs from the tubed amps (RH84 monoblocks in this case) into the high level inputs of the sub amp. We ran it both ways - in parallel (i.e. the horns ran "full range" and the sub rolled in at whatever setting we played with) and series (from the main amps to the sub amp, and connecting the horns to the speaker level output)

One of the limiting uncertainties of the budget class of integrated plate sub amps is the quality and exact topology of the crossover networks, particularly the slope of the high level high pass output. Another is legibility and accuracy of calibration on the crossover frequency control.

Anyway, we found the least obnoxious integration when dialed in anywhere between "60 - 80Hz". If I'm sounding less than enthusiastic about using a powered sub, at least for audio only - you're right, but don't let that dissuade you.

[planet10]

More pictures up, and a few comments on a comparison of the alpha build to the modified B-Horn reference.

dave

[jleaman]

And, just so people done have to go back a few pages for the link dave is talking about here it is once again..




http://www.planet10-hifi.com/alpha121.html

[Ropie]

Just thinking aloud from an aesthetic point of view dave, would this completely kill the design? Just looks a bit different and makes use of that nice rear slope..

[planet10]

Cool aesthetic, but you just wiped out the mouth

If you look at any rectangular RL-Horn the biggest areas available for mouth are the back & the sides. A horn this size has to corner loaded, so for simplicity using the back makes sense. Even thou the top part of the mouth in these may not be fully functional it does use the entire back.

Ron Clarke is working on optimizing the mouth as much as possible, expect to see some crescents and don't be surprised if the bottom of the side panels extends back some more.

dave

[johninCR]

I like the looks of Ropie's idea and you could add a square flared final segment. A bit tricky for the cuts and I know it would enlarge the footprint, but I'm a sucker for the sculpture look. In this case it would serve a good function too.

[planet10]

Originally posted by johninCR
I like the looks of Ropie's idea and you could add a square flared final segment. A bit tricky for the cuts and I know it would enlarge the footprint, but I'm a sucker for the sculpture look. In this case it would serve a good function too.

Something like that has been floating around in my head for a long time (an integral part of a horn that's need was greatly diminished by the RobHorn A126).... i had semi-planned to see if similar worked for the Frugel-Horn, but getting a more conventional version out the gate keeps that extenson (pun intended) till after a 1.0 version of the horn. As i envision it it would play havoc with the flare too

dave

[johninCR]

Me likely. That is closer to what I envisioned from a hint you posted about a year ago about a Bhorn with a bigger mouth. That shape should be fun for Ron to get round output out of.

[Ropie]

Mightn't something like this help in the absence of a full mouth?



Again, it's just good to play with things a bit, even though I think this it's a very neat little design straight out of the box, as it were. I just know that Ron is going to come up with the goods anyway!

[Variac]

Ropie has a good design eye. If we can make his ideas work they are beautiful