FE168E or fe208e, that is the question

[scal]

fe168e sigma vs fe208e sigma + tweeter ?

Testing my project based on fe168e sigma since few days now, and i'm afraid that the 168 are not "big enough".
The main pb: missing bass ("grave" in french)
As i'm a newbe in that domain, the pb may come from an other thing.. But i think with bigger hp i'll have more bass, and i'll correct with a tweeter( ft90) if necessary.
Before any change of size, i'll try to modify the sound with various insulation. I don't know how for instance

More pic here: http://scalblog.blogspot.com/

More pics

[Scottmoose]

Beautiful work! Wish I could build them like that!

Re the lack of bass, without more information, I doubt we canhelp much. Can you give some details of the design (flare, length, throat & mouth areas, chamber volume, the driver you designed it for etc.)?

Sticking a larger driver into the cabinet won't automatically give you more LF -horns are relatively independant of driver CSA. It should shift more air in itself, but for the rest, I'm not sure I'd expect a dramatic change.

[zobsky]

In general, the 8" fostex will give you more (quantity, quality and dynamic) bass (with the right cabinet, of course, .. don't stick it into the cabinet you built for the 6.5" drivers !!!). The treble can be fixed with a tweeter, but the midrange will be a bit better with the 6.5" .

In either case,I think the E-sigma drivers need a tweeter.

Overall, if you are looking for that "big" sound, I think the 8" will be a better choice.

[JimT]

I have tried something similar so my experience may help. I made a MLTL with the FE167E. It did not have low enough bass and could not play loud. I then tried the FE207E in a new MLTL. The FE207E could play lower and louder, but I did not like the mids or highs. Neither were optimal designs, just quick testers so better designs may help. Still my next move is to go back to the FE167E or maybe a FE107E, but this time with subwoofers.

Jim

[scal]

Originally posted by Scottmoose
Beautiful work! Wish I could build them like that!

Re the lack of bass, without more information, I doubt we canhelp much. Can you give some details of the design (flare, length, throat & mouth areas, chamber volume, the driver you designed it for etc.)?

Sticking a larger driver into the cabinet won't automatically give you more LF -horns are relatively independant of driver CSA. It should shift more air in itself, but for the rest, I'm not sure I'd expect a dramatic change.

Thanks for the compliment !
Here more technical informations:

throat : 50cm2
mouth area: 1188cm2
horn length:238cm
chamber volume:6.5L
Driver mounted: fostex fe168e sigma:160mm, Vas23.7, Qts0.26 (http://www.fostexinternational.com/d...df/fe168ez.pdf)

What do you mean by "flare" ?

More test this evening, it realy depend of the music you play. Tried bach celo concerto, bob marley, rolling stone, vivaldi organ concerto... interesting. I realy miss deepness(?) in bass with celo concerto. Do you think that insulation, sound absorbents or other treatment inside will change something ?
Discovered also that the room(studio) configuration is important, unfortunately i test in very poor condition for the moment. (still building my house )

[scal]

Originally posted by zobsky
In general, the 8" fostex will give you more (quantity, quality and dynamic) bass (with the right cabinet, of course, .. don't stick it into the cabinet you built for the 6.5" drivers !!!). The treble can be fixed with a tweeter, but the midrange will be a bit better with the 6.5" .

In either case,I think the E-sigma drivers need a tweeter.

Overall, if you are looking for that "big" sound, I think the 8" will be a better choice.

> In either case,I think the E-sigma drivers need a tweeter.

Thanks.
I tried this evening with a poor tweeter stolen on a poor portable radio, it bring an other dimention, indispensable for pop music but not for classical.
Anyway before changing for 8" driver i'll try all possible adjustment with the 6.5".

[scal]

Originally posted by JimT
I have tried something similar so my experience may help. I made a MLTL with the FE167E. It did not have low enough bass and could not play loud. I then tried the FE207E in a new MLTL. The FE207E could play lower and louder, but I did not like the mids or highs. Neither were optimal designs, just quick testers so better designs may help. Still my next move is to go back to the FE167E or maybe a FE107E, but this time with subwoofers.

Jim

> but this time with subwoofers.

Why not... & wich type off subwoofer you think about ?
thx

[planet10]

Originally posted by scal
mouth area: 1188cm2

I realy miss deepness(?) in bass

With a horn, how low the horn goes ican be approximated by the mouth size... you have a front firing mouth, it is sitting on the floor so that effectively makes it 2x as big... 2376 cm^2. If we take a circle of that area we get a circumference of ~173 cm, which gives us a horn mouth good to ~200 Hz... below that any bass is produced by transmission line action... once Scott knows the expansion rate (flare) of the horn he can model it and get an idea of what its FR probably looks like.

dave

[Scottmoose]

Originally posted by scal
throat : 50cm2
mouth area: 1188cm2
horn length:238cm
chamber volume:6.5L
Driver mounted: fostex fe168e sigma:160mm, Vas23.7, Qts0.26 (http://www.fostexinternational.com/d...df/fe168ez.pdf)
What do you mean by "flare"?

OK, that's a good start. The flare of the horn is, as Dave says, the horn profile / expansion rate you used. There are a few: exponential, conical, parabolic, catenoid, hyperbolic, hypex etc. Exponential is the most commonly used.

[zayne742]

Scal,

You need to check out the BIB thread. Scottmoose, Planet 10, and Godzilla are the masters on the subject. Also, GM, read everything they have posted. That is where you will regain your deepness and range. Plus you already have a good set of drivers for the project.

That is an absolutely beautiful cabinet you have built!