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View Full Version : Question about back loaded horn construction



ballstothewall
12-14-2005, 04:43 PM
Ok, I am building a back loaded horn enclosure for fostex's FE103E driver.

The plans are here... http://www.madisound.com/pdf/fostexcabs/103e_enclrev.pdf

I was just checking to make sure that it won't matter if I use a round over bit on all internal edges, to give it a smooth laminar airflow. It will be constructed out of 1/2" birch ply on the inside, with a walnut exterior. I will be putting felt in the space behind the driver, and I should put it in the opening of the horn??

Thanks for any input, I will be sure to post some pics when I'm done, and maybe some along the construction...

-Ryan

JimJ
12-14-2005, 05:27 PM
Some people like the horn mouth unlined, some feel it smooths out the bass response...only way would be to tack it up temporarily and see if you like the difference.

thadman
12-14-2005, 05:34 PM
I was recently having a conversation with someone who mentioned to me that there is virtually NO imaging with bass horns and NO soundstage. Is this true?

Sorry to get off subject

ballstothewall
12-14-2005, 05:36 PM
Alright, Thanks Jack.

JimJ
12-14-2005, 05:39 PM
I was recently having a conversation with someone who mentioned to me that there is virtually NO imaging with bass horns and NO soundstage. Is this true?

They need to clean out the wax in their ears.

The only complaints I've heard with horns is if you cross them over too low, the substage tends to get muddied and lack definition. Which is why unless you go with absolutely huge, Nelson Pass-sized horns, you wouldn't want to play them extremely low. Transmission lines have better subbass clarity than horns, but at a significant efficiency cost.

thadman
12-14-2005, 05:45 PM
I believe this is exactly what he had mentioned, I was contemplating horn-loading some 8" fullrange drivers (looking into audio nirvana and fostex at the moment) for a budget <$300 5 channel HT setup but after hearing this...I was having some more thoughts.

There is virtually NO imaging with bass horns and NO soundstage. I have never tested one that is 'flat' below about 63 cycles. Moreover, the bass response is so ragged that they are plus 8 dB for a 1/3 octave change, then negative 9 dB for the next 1/3 octave. They are the poster child for soupy 'one note' bass. An answer to a question that no longer exists. They were designed in the 30's when amplifiers were less than a watt. They are really nothing more than an old cheerleaders cardboard megaphone, folded to fit in a box. Does someone sound natural when they shout through one of these? Then how can music sound natural? Like everything else in audio, they are built because they look 'cool' and people can impress their friends.

ballstothewall
12-14-2005, 05:49 PM
Tell ya what thadman, when I get them built, I will tell ya how they sound. I don't have all that much experience with audio, but I can tell what sounds good, but I don't know all the terms to explain what I like and don't like.

JimJ
12-14-2005, 05:50 PM
No, the bass response isn't flat. Neither is a bass reflex :)

I wouldn't say they're "one-noted", because a good horn setup is far from it. And the fact that he thinks low powered amplifiers remained in the 1930's is another sign of his ignorance :)

thadman
12-14-2005, 06:18 PM
Another message from the same guy, he seemed like he knew what he was talking about. I asked him if since horns are so terrible why does fostex recommend them and provide plans?

->
While Fostex makes good fullrange drivers, in my humble opinion, Fostex doesn't have a clue about making good cabinets. While they make tens of thousands of drivers annually, they sell relatively few complete systems. Why did they recommend bass reflex for the FE204 that preceeded the 206? Frankly, I think they are mostly copying Lowthers. Lowthers have been made for about 70 years and their main market was the bass horn crowd. Fostex drivers are really 'budget' Lowthers. Lowther, for example, invented the 'whizzer cone' 60 years ago or so. And Fostex doesn't know much about tuning bass reflex either.

In my circumstances, budget HT setup for an Xbox 360/Computer/Home Theater <$300 for all channels (5). Would It benefit me to build horns over bassreflex cabinets? The horns would require MUCH more buildtime on my part and would most likely, be MUCH larger.

The 360 has an audio processor, although it does not seem like anything other than a "last-second addition to the console"

* Multichannel surround sound output
* Supports 48 KHz 16-bit audio
* 320 independent decompression channels
* 32-bit audio processing
* Over 256 audio channels

Would I be better off running a fiber optic cable straight from the 360 to an amp or running RCA cables to my Pioneer reciever (it is a budget reciever from 2000-2001~ from a HT in a box $600 system) The speakers are 98dB 1w/1m so Im sure I wouldnt need more than 10+ watts per channel.