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
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
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
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
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.
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.
>>> There is far, far too much bass. The sound is very "muddy" without much treble at all.
I think you should try adding a super tweeter like Verk did.
My Pioneer B20s sounded bad until I added a tweeter. Your drivers probably need a tweeter and in combination with the BIB adding bass and mid bass this problem is exagerated. I added a super tweeter on the rear. This way you don't spoil the point source look but gain the benefit of some additional tweet.
http://www.zillaaudio.com/fostex-165k-bib.htm
Depending on how low you need to 'crossover' the tweeter it may sound better facing forward.
Please report back.
Godzilla
I think you should try adding a super tweeter like Verk did.
My Pioneer B20s sounded bad until I added a tweeter. Your drivers probably need a tweeter and in combination with the BIB adding bass and mid bass this problem is exagerated. I added a super tweeter on the rear. This way you don't spoil the point source look but gain the benefit of some additional tweet.
http://www.zillaaudio.com/fostex-165k-bib.htm
Depending on how low you need to 'crossover' the tweeter it may sound better facing forward.
Please report back.
Godzilla
Godzilla
What are the dimensions of the cabinet in your link?
Anyway...I've opened them up and have pretty much established the side being screwed in place isn't ideal, but I need the access for now. There is definitely going to be some leakage going on but I'm putting up with that for now in lieu of messing about with the internal damping material.
I changed the amount and placement of the stuffing and it's changed the sound, bringing about a dramatic improvement.
I only have 'x' amount of damping material but I have copious amounts of long-haired wool. What I've done is stuff the cavity immeidately above the driver with long-haired wool that HAS NOT been 'tweaked out,' so that area is stuffed with large and thick amounts of long-haired wool. Immediately behind and extending to about 6" below the driver I've added some normal loudspeaker damping material, with long-haired wool also placed around the neofone basket. There is space behind the stuffing that is below the neofone, it's only a 1" thick layer of damping material. I may increase that. The rest of the cabinet is stuffed the same as it was, there is ~2" of material on the bottom of the cabinet and nothing else.
It is now really, really good. The change is unbelievable and makes me wonder how far I can go with this, how much more might be possible from the NF in a BIB by adjusting the stuffing of the cabinet. Maybe it does need a treble unit, which is a shame as I recently sold a pair of un-used Fountek ribbons that I didn't need when I put the NF in a bass reflex enclosure. Ultimately this didn't work but there was bags of treble.
I'll have to come to a stop on this at some stage and glue the side in place, something which is bound to improve things even further, but I'm going to do a bit more with the wadding before I do that.
If the NF ultimately isn't ideal for a BIB I am now convinced of the principle so may end up going for a driver that is known to produce a good result in a known cabinet.
Thanks for the replies so far. Much appreciated.
What are the dimensions of the cabinet in your link?
Anyway...I've opened them up and have pretty much established the side being screwed in place isn't ideal, but I need the access for now. There is definitely going to be some leakage going on but I'm putting up with that for now in lieu of messing about with the internal damping material.
I changed the amount and placement of the stuffing and it's changed the sound, bringing about a dramatic improvement.
I only have 'x' amount of damping material but I have copious amounts of long-haired wool. What I've done is stuff the cavity immeidately above the driver with long-haired wool that HAS NOT been 'tweaked out,' so that area is stuffed with large and thick amounts of long-haired wool. Immediately behind and extending to about 6" below the driver I've added some normal loudspeaker damping material, with long-haired wool also placed around the neofone basket. There is space behind the stuffing that is below the neofone, it's only a 1" thick layer of damping material. I may increase that. The rest of the cabinet is stuffed the same as it was, there is ~2" of material on the bottom of the cabinet and nothing else.
It is now really, really good. The change is unbelievable and makes me wonder how far I can go with this, how much more might be possible from the NF in a BIB by adjusting the stuffing of the cabinet. Maybe it does need a treble unit, which is a shame as I recently sold a pair of un-used Fountek ribbons that I didn't need when I put the NF in a bass reflex enclosure. Ultimately this didn't work but there was bags of treble.
I'll have to come to a stop on this at some stage and glue the side in place, something which is bound to improve things even further, but I'm going to do a bit more with the wadding before I do that.
If the NF ultimately isn't ideal for a BIB I am now convinced of the principle so may end up going for a driver that is known to produce a good result in a known cabinet.
Thanks for the replies so far. Much appreciated.
Success is nice, eh!
I ended up with pretty hard packed polyester fibre at the top, ending just above above the driver. ~10mm BAF, side and back wall around driver, extending 20cm below driver. I then added 3mm wool all the way to the mouth.
But that was with a low q driver....
Seal it and if you still have too much bass, it will be easy to adjust thru the mouth.
Peter
I ended up with pretty hard packed polyester fibre at the top, ending just above above the driver. ~10mm BAF, side and back wall around driver, extending 20cm below driver. I then added 3mm wool all the way to the mouth.
But that was with a low q driver....
Seal it and if you still have too much bass, it will be easy to adjust thru the mouth.
Peter
I built a good sounding BIB
The title of the thread should be changed now.
Following the helpful suggestions of others and sorting out the stuffing this BIB now sounds very, very good. I'm very impressed with this now.
I'm still going to tweak them to see how much more can be had from this design, I need to spike the bases, for example. I'll also had a circle of wood to the front if only to move the driver further out, which will allow me to add a further layer of damping material directly behind the NF should I feel it needed.
I've ended up with :
1. Compacted above the driver with long-haired wool to a point just above the driver.
2. Immediately behind the driver are 2 layers of loudspeaker damping material.
3. Extending to roughly 6" below the driver on the inside of the baffle is one layer of damping material.
4. Roughly 2" of compacted long-haired wool is sitting at the base of the cabinet.
5. The inside of the mouth from the bottom of the wood to about 6" from the top of the inside is lined with loudspeaker damping material.
I'll continue with the side screwed in place for now while I continue to assess the speakers, especially as I expect a change when I get some spikes for them.
I'm confident I'll be using these over the longer term so I need to think about how to finish them off.
Thanks
The title of the thread should be changed now.
Following the helpful suggestions of others and sorting out the stuffing this BIB now sounds very, very good. I'm very impressed with this now.
I'm still going to tweak them to see how much more can be had from this design, I need to spike the bases, for example. I'll also had a circle of wood to the front if only to move the driver further out, which will allow me to add a further layer of damping material directly behind the NF should I feel it needed.
I've ended up with :
1. Compacted above the driver with long-haired wool to a point just above the driver.
2. Immediately behind the driver are 2 layers of loudspeaker damping material.
3. Extending to roughly 6" below the driver on the inside of the baffle is one layer of damping material.
4. Roughly 2" of compacted long-haired wool is sitting at the base of the cabinet.
5. The inside of the mouth from the bottom of the wood to about 6" from the top of the inside is lined with loudspeaker damping material.
I'll continue with the side screwed in place for now while I continue to assess the speakers, especially as I expect a change when I get some spikes for them.
I'm confident I'll be using these over the longer term so I need to think about how to finish them off.
Thanks
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