B&G Neo8 Measurements

[Tenson]

Hi,

I put a Neo8 in to a baffle as pictured, a bass driver was also added.

It then had a small enclosure behind it. About 5" wide by 9" high and 2" deep and filled with foam.



The baffle simulation I did suggested a smooth 3dB rise around 1KHz, like the B&G PDF file did with their 9"x9" baffle.

However, I seem to be getting some odd results. A rise, where it starts to roll-off on the other measurements I have seen!

Could this be caused by the small enclosure? Should I be using it open baffle?

It sounds kinda boxy and pretty sibilant and harsh, which I suspect is due to the huge peak around 10.5KHz, which is usually notch filtered out.

Anyway thoughts appreciated.

[okk]

you can check the result without 1/3 oct filter.
may be there are some clues to find.

[Will]

Are you Neo8 runned in already ?

[gp4Jesus]

a larger deeper enclosure may tame that mid-bass peak.

Can't comment on the sibilance; likely due the natual peak shown in the BG's documentation. If you follow BGs notch filter recommendations, that MAY fix the sibilance and harshness.

I thought these WERE open baffle drivers; just screw to the front baffle!

Tony

PS you may want to follow an older "busy" post on these drivers!

[Tenson]

It was indeed due to the small enclosure. I have put them in an open baffle config now and they sound much better. Currently tuning the Xover. They sound good, but I have to say I'm surprised they get such comments about their high quality, they don't sound that brilliant. Great imaging though!

[gp4Jesus]

What freq did you XO them?

what's the response below 1K hz?

I plan to bi-amp them in an MTM config for my left, center, and right channels, cone drivers yet to be determined.

love to get the specifics on your XO as my rear channels may be passive.

Cheers

tony

[Tenson]

I have taken some measurements for you. They were done in close proximity (30cm) and at about 30degreese off-axis. I used a 10ms gate on a 5second MSL recording. Frankly, I think the Neo8 is crap.

Neo8 on a 9" x 9" baffle



Neo8 with high cut



Neo8 with high cut and 6dB But Xover at 1.6KHz



Now that looks quite good doesn't it? Pretty flat and could cross with a woofer at about 700Hz with a high order Xover.

BUT, you now put the thing with baffle, on top of and in line with the front of the woofer cab.


Hmm.. oh dear!

You try moving the Neo8 baffle back 1"



Now I tried doing similar EQ so it was as flat as possible (I know that doesn’t equal good sound but its better than huge suckouts and peaks in random places) while on top of the woofer cab and it did get quite good but still had a peak around 950Hz. Lucky for me the Dayton 7" aluminium woofer I am also using has a slight peak at about 950Hz as well. So, I crossed it over just right and with an inverted phase so that it counteracted the peak of the Neo8. Well, this was as flat as it was going to get. Sorry I don't have a measurment.

The tonality was pretty good, though lacking upper treble. Something I am pretty sensitive too as I hear very high. But, even so, it just doesn't sound very good. Vocals and imaging are not bad, but no better than any other 'good' speaker and it is pretty bad at most other stuff!

Though the Dayton woofer does go nice and low with tight bass. My next plan is to try a single Jordan JXR6 crossing to the Dayton at about 350-500Hz. Any thoughts on how this might turn out?

Thank-you for your time!

[Tenson]

I just took some measurements of the Neo8 as flat as I can get it on top of the speaker.



Now I integrated the woofer with a 24dB Butterworth Xover. Not very easy to do passive but never mind for now. Oh, with this higher order Xover there was no need to invert phase to cancel the 950Hz peak. It just popped on the end of the Neo8's response. At these lower freq my room will start to show itself BTW so ignore below 300Hz.



Now a measurement at my listening position.



How does it sound? Well.... Okay I suppose it is not BAD. But it is not GOOD by any means. I think the woofer needs to be crossed lower down and the Neo8's frequency response is dire.

I suppose it could work quite well in a centre speaker with no baffle above or below it and small midrange only speakers on either side.

[ScottG]

other than the lack of freq. response linearity.. could you describe what is both wrong with it and right with it? I have a feeling that mechancial resonance is kreeping into the audible range and causing some problems, but I'd like to get your subjective opinion..

also what type of amplifer are you using.. specifically does it provide high dampening factor (via low output imepance) or not?

is the imaging still great, or mearly not bad? what about other aspects?

thanks!

[Tenson]

Well, the main thing is the FR linearity with the Neo8. Even after EQ it just doesn’t sound right. I can hear the lack around 2.5KHz.

It also just sounds confused. I think the main reason for this is the woofer isn't very good above about 400Hz and while the Neo8 can cross pretty low (lower than other 'tweeters' anyway). Put that and the dire linearity together an the speaker just doesn’t sound good lol.

I think for these reasons a JXR6 (anyone want to sell a pair?) would work well as it is very linear and can cross extremely low. SPL might be a problem but I’ll have to compromise between Xover and SPL.

Oh, the amp for the tweeters is a class A Monarchy Audio 70 thingy. Woofers is a level matched Technics. Not great but not bad and its not the cause of the confusion lower down.