Neofone - I built a very bad sounding BIB

[Brain]

Folks

I finished building a BIB for the Neofone's today. There is far, far too much bass. The sound is very "muddy" without much treble at all.

I used both BIB calculators to come up with the cabinet dimensions of :

Line Length 125.37"
Folded Height = 62.68"
Depth = 10.39" (internal)
Width =7.35" (internal)
zdriver = 27.2"
a-b-c = 5.2"

The parameters of the NF are:
FS = 53.7
VAS = 11.5L
Qts = 0.42

I've stuffed the cabinet as per the 2nd stuffing option shown on the same link as above. In the bottom of the cabinet I've put about 2" thickness of damping material purchased from World Designs specifically for the purpose of lining loudspeakers.

Note that I just noticed when looking at the picture in the link that I haven't stuffed immediately behind the NF, I've stuffed above it. I'll change that as a first attempt at sorting this out but the sound is really so bad I think the cabinet must be the wrong size.

Any advice appreciated.

Thanks

Brian

[Landroval]

Have you used the Neofones in any other cabinets and if yes did you then like the sound, ie. had enough treble etc?

[badman]

Originally posted by Landroval
Have you used the Neofones in any other cabinets and if yes did you then like the sound, ie. had enough treble etc?

There's that, they probably want a supertweeter to your (OP) ears. Also, if they're bass heavy, you're in an enviable position. Add some more stuffing to play it down to taste, and you can have less ripple and a cleaner impedance curve (depending on how much stuffing you use)

[peterbrorsson]

Hi,
With this small cavity behind the driver, damping is essential. I have the opinion that it is one of the most important thing. Specially with a thin cone. You get reflections thru the cone and it blurs the sound for sure. Neophone is said to need help upwards treble, but personally, I have no experience with this driver.

For me it's good to have too much bass, just damp rest of the pipe until your'e satisfied. Maybe you get rid of the ripple in this type of box!

Peter

edit: Badman, you beat me within seconds

[vitalstates]

Hi Brain

I might have missed something here, but.........what amp are you using???

just because there was a library and the vicar happened to be visiting, doesn't necessarily mean that the vicar did it in the library.

just a thought

Ed

[verk]

Hi Brian

I built Neofone BIBs about a year ago to these measurements.
Used an inexpensive Foxtex supertweeter, FT7H with LPads.

These drivers do need a supertweeter!

Line length: 128 in
Zdriver: 25.75 in
Sm: 55 sq in

Overall sound was very, very good, bass down to 30s.

Verk.

[Brain]

Thanks for the replies.

The amp is the Diy HIFI Supply Django/Ella PP.

I've tried the NF in a ported box to the dimensions recommended at the time on Brian's website and had to tame the treble with a correction circuit. I think the NF is capable of treble, I'm just not hearing it in the BIB.

When I built the BIB I used screws for one of the side panels for easy removal, expecting I'd need to make adjustments. I'll sort out the stuffing behind the driver tomorrow when I get home from work.

[steve shiels]

Originally posted by Brain
Thanks for the replies.

The amp is the Diy HIFI Supply Django/Ella PP.

I've tried the NF in a ported box to the dimensions recommended at the time on Brian's website and had to tame the treble with a correction circuit. I think the NF is capable of treble, I'm just not hearing it in the BIB.

When I built the BIB I used screws for one of the side panels for easy removal, expecting I'd need to make adjustments. I'll sort out the stuffing behind the driver tomorrow when I get home from work.

my experence is with lowther horns, i found that too long a horn would have the same effect, so you may be right abot the box having that effect..
in saying that i found most lowther horns too short..making the speaker sound unbalanced (too forward)

steve

[peterbrorsson]

When I built the BIB I used screws for one of the side panels for easy removal, expecting I'd need to make adjustments. I'll sort out the stuffing behind the driver tomorrow when I get home from work.

Could be that they are leaking, not a good thing....

Personally, Bib's are not something I can live with, due to the ripple.

Good luck,
Peter

[Brain]

Yes, I'd considered that and hope it isn't the case. It's going to be difficult to access the inside once fully glued up. I may just add more stuffing and then go for it this evening with the glue.

Cheers