[fu_man]

Hi can  anyone please advise?
I want to build some front loaded horn  speakers ( with a design cutoff  frequency of 140hz)  The  fostex FE 206 E  would be  the right  driver to use, but I am  keen to know if there is an  equivalent  Hemp cone  driver  that I could use.

Thanks.

[andyr]

Hi can anyone please advise?
I want to build some front loaded horn speakers (with a design cutoff frequency of 140hz)  The fostex FE 206 E  would be the right driver to use, but I am keen to know if there is an equivalent Hemp cone driver that I could use.

Thanks.

Sorry ... what's the point of speakers which have a designed cutoff frequency as high as 140Hz??   

(How do you compensate for the lack of the 30/40-140Hz frequency band?)

Regards,

Andy

[JLM]

Yeah, 140 Hz cutoff?  The free air response of the driver is only down a couple of dB at 140 Hz:

http://www.fostexinternational.com/docs/speaker_comp/pdf/fe206erev.pdf

The Qts of the driver will dictate the proper enclosure type.  Qts = 0.2 is ideal for horns, 0.8 for open/infinite baffles, in between for the rest.

If you want the most synergistic, musically satisfying sound pick the driver first, then build what's best for it.  Those who try to fight the laws of physics are primarily experimenters and/or hobbists, not audiophiles IMO.

[andyr]

Yeah, 140 Hz cutoff?  The free air response of the driver is only down a couple of dB at 140 Hz:

http://www.fostexinternational.com/docs/speaker_comp/pdf/fe206erev.pdf

The Qts of the driver will dictate the proper enclosure type.  Qts = 0.2 is ideal for horns, 0.8 for open/infinite baffles, in between for the rest.

If you want the most synergistic, musically satisfying sound pick the driver first, then build what's best for it.  Those who try to fight the laws of physics are primarily experimenters and/or hobbists, not audiophiles IMO.

Sorry, JLM,

You've lost me.     I'm not talking about fighting the laws of physics or building speakers, per se, or selecting drivers ... all I'm saying is, AFAIAC, a speaker needs to have a -3dB point of 40Hz, max, to deliver a good sound.  So 140Hz is kinda "shabby"!!   

Regards,

Andy

[JohninCR]

Guys,

First you are debating about something you agree upon, but you both missed that the gentleman said front[/i] horns, so there's absolutely nothing wrong with a 140hz cutoff, because it has to be multiway.  He's asking about a similar performance hemp cone driver.

Sorry I don't know of one.

[fu_man]

Thanks everyone,
Yes,  JohninCr that's  correct it will be a two way.  I'm not  sure  what the  bass solution  will be yet, although i  see a number of Avantgarde uses have swapped their 225 twin 10" subs with the small VBT/TBI subs ... now those seem more like a  "fight the  laws of physics" type of topic. 
I will freely admit to not knowing too much about speaker design, so I am assembling a speaker rather than designing one. The Fostex FE206E is used in this application eg, Oris 150 horn. (the reviews of the hempcones, their  use  by Loius,  and by  Audionote  just got me  thinking)... so as you say,  looking for a  similar performance hemp driver.  Maybe I’m S.O. of luck?
So a QTS of 0.2… is that the only thing I really need to look for?

Thanks

[JLM]

andyr,

I agree with you 100% regarding the need to go deep (I'd recommend going down to 30 Hz in room flat for music).  I was just wondering what the point of using a horn was if it's only helping a couple of dBs.

fu man,

The problems I've heard with front loaded horns are:  1.) the speed of bass needed to avoid it's sound becoming disjointed from main driver; 2.)  the high crossover point needed (140 Hz is mid-range and within the range of the human voice); 3.)  the "forward" presentation of the associated drivers and the horn itself require a deep room to tame and allow the soundstage to develop. 

The designer/principals of VBT/TBI are suing each other, so no telling when they'll be available again.  The design is patented and I'm not sure anyone on the outside knows just how they work so well for being so small.

If you're assembling, versus designing a speaker (smart choice for 99.9% of us IMO) I'd pick a design and stick with the recommended parts.  Playing around with designs is a "proceed at your own risk" game.  Yes a low Qts driver fits horns best.

A few years back a company named Two Rivers (I think) marketed a front horn to fit 8 inch drivers that was cheaper than the Oris, but looked like truck wheels.  They used them with Fostex FE206E drivers and Yamaha servo subs.  All together the cost was around $1,000 USD.  Personally I don't "get" the appeal of the FE206E's but if this is about the cheapest possible route to try something close to full range sound with a front loaded horn.

[Duke]

I've built several speakers with the Fostex FE206E and several with horns, but not in the same system.   

One advantage to a front-loaded horn is good radiation pattern control over a wide frequency range.   In my opinon radiation pattern is overlooked by far too many loudspeaker designs.   The downside can be a frequency response problem, which then has to be addressed in the crossover (something that can be intimidating for many DIYers).   

My general suggestion would be to stick with a driver/horn combination known to work well, unless you are comfortable with making your own measurements and designing your own crossover.

That being said, after eyeballing the Hemp Acoustics FR8.0DIYHQ, it looks promising to me as a candidate for an Oris-type horn.  It looks to me like the gently rising response could  synergize well with the horn loading, making the crossover easy.  You might contact the manufacturer or one of their dealers.

http://www.hempacoustics.com/

Best of luck with your project!

Duke

[fu_man]

okay,  thanks for the encouragement, and  providing the  voice of reason.
We  all get  carried  away at times  don't we?

JLM
I understand what you mean about the forward presentation, I heard a pair last Friday and thought they sounded  the  most like live music I have  ever heard, very forward in their presentation.  I've  read the 6 moons  review of the Horning Hybrid  which noted this point (not about the HH's) , that you don't  always want a band in your living room.  Apart  from this, this  space required as you mention is an important  factor.  I  am  really impressed, but  whether they  will be  suitable in my room, and ultimately to my liking  i  want to find out. And, that's  why  I want to use the  Fostex's... they  are a whole lot  cheaper than  Lowthers  or   AER's,  so if  the project  ends up a  dead  end, then at  least I've  had  some fun,  learnt a  thing or  two,  satiated  a  long term curiosity, and haven't   spend a  fortune to do so.  ( If i do like  them... i  can always upgrade the driver.)
You and Duke  are of course  perfectly correct....  without any  experience or  handy reference  how will evaluate them if i don't know that the  driver is  doing  what it should be  doing... to do that i  need  a tested solution... and  yes... designing a  crosover 'fix' is  somewhat  daunting. 
I hadn't  seen those Twin Rivers before....yup they do look like  truck wheels    my horns  will of course  look much prettier!

Maybe I should  try this horn project:
http://www.big-horn.com/images/640x480.jpg


Duke,  that's  really cool...  thanks for the  advice and  encouragement.  By the  time I get  my horns together I'll probably have a pair of  Omega hemp drivers  for the open baffle, and if I really like the  qualities  these cones  have then I can start thinking of  more crazy things.

PS  bummer  about  VBT/TBI...

[willbixb]

The rumor of VBT and TBI is very FALSE. There is NO litigation. The revolutionary and patented technology is and has always been TBI. TBI is alive and doing quite well. The subwoofers, amps and new loudspeakers are all available and sound better than ever. Now start chanting H.D.S.S. 

www.tbisound.com

[fu_man]

Willbixb,
I'm a little new here myself, but  welcome to  the  A.C.

Thanks for your  reply,  are you associated with TBI or  a  happy owner?

would love to hear more impressions on these subs.

H.D.S.S...  sorry  didn't catch on???

[opnly bafld]

H.D.S.S. on the TBI website- High Definition Sound Standard

[fu_man]

are you sure  TBI  aren't out of business?  I haven't  had  a  reply to my  email from almost a week ago... mind you Hemp acoustics haven't  replied in  over  2  weeks!

Is  this unusual or have I  just been spoilt by the excellent  service  from Red Wine  and Omega?

[ohenry]

TBI is alive and well.  I just contacted Jan Plummer (owner) a few days ago and he stated that there is no litigation issue affecting product development, manufacturing or distribution.  However, I don't understand why you aren't getting a more prompt response.  In the few times I've tried, he has replied within two days.  You may want to try again to ensure the e-mail is being received.

BTW, I have two Magellan VI's powered by a TBI SU200 amp and I really am content with the quality and quantity of bass.  Just the thing for adding a little oomph to single driver speakers, seamless presentation.

[willbixb]

  Hi fu_man

yes I am a very proud owner of a pair of Majestic Diamond 1's , (1) Magellan VI and (1) Magellan VIII.  A complete single source (driver) system. No crossovers. I am in real audio heaven. My natural highs and lows are present and pure. I use the Diamonds for my Ipod when on travel and connect them back to my 2.1 set up when home.. Extremely versatile little buggers.