| B&G Neo8 Measurements - Click HERE for Original Thread |
| 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.
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| okk |
you can check the result without 1/3 oct filter.
may be there are some clues to find. |
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| Will |
| Are you Neo8 runned in already ? |
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| 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! |
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| 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! |
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| 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 |
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| 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 ****.
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! |
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| 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. |
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| 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! |
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| 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.
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| ashok |
I've tried the Neo8 with a woofer and 24db/octave active crossover . It sounded better than my upgraded Mission 701's. Extreme HF was a bit down but I added a Neo3 and it filled it up. I plan to rig it up again with some refinements.
The Neo's were on an open baffle.
I think it sounded very good . I' did not use a notch filter but played around with the passive crossover between the Neo3 and Neo8. They added up very nicely. I looked for the files on my computer but can't find them. Might just have to rig up everything again.
Cheers. |
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| ScottG |
| quote: | Originally posted by 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.
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LOL! :D
You could try horn loading within a specific passband:
http://www.diyaudio.com/forums/show...10&pagenumber=6
I think the real problem is the resonance. It isn't that high in amplitude on any other measurements I've seen from other sources. Bad drivers?
The amp is likely a low output impeadance desing which tends to overdampen drivers in this range - particularly ribbons - but also anything with low mass for a given sd. (like the BG planars AND the Jordan JXR6). An autoformer might work well here for the Monarchy - just don't use it on the bass amp as well.
The "confused" sound could well be the rear phase output bouncing around in your room. However, it could also be a "time" problem - note that the excursion of your midbass is QUITE different than the Neo 8. IF thats the problem the JXR6 should definity be a cure (beyond that of the issue with linearity), because its own excursion should more closely match that of the midbass at moderate spl's. (..and yes, I don't think the Jordan will cut-it for high spl's and a low cut-off freq. - could be wrong though.) |
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| gp4Jesus |
did I miss something?
| quote: | | ...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! |
now they sound like trash??!! didn't they sound good B4?
I'm confused.
tony |
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| Tenson |
Well, they sound a lot better on an open baffle than in a heavily damped small box.
I tuned the crossover a bit more outside today (fuk its cold!) to get more accurate measurements.
It sounds better again now I have done that. I am now using a 12dB butterworth on the woofer and a 6dB butterworth on the Neo8 but at about 2.4KHz to counteract the peak lower down. I then added a 4.5dB notch filter at 750Hz which fixed the peak pretty well.
Quite a complex crossover that I don't want to do passive :( But it does sound reasonable.
Anyone got an idea of how high the JXR6 would need to be crossed to get enough SPL for metal and rock stuff in a small room? |
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| ScottG |
| quote: | Originally posted by Tenson
Anyone got an idea of how high the JXR6 would need to be crossed to get enough SPL for metal and rock stuff in a small room? |
Think smaller rear chamber with aperiodic vent - not high crossovers. |
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| Tenson |
How come?
I'd have thought the low frequencies would be the limiting factor for power handling. Are you suggesting using a small enclosure to give a natural LF roll-off rather than actually limiting the signal sent to the driver? |
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| ScottG |
| quote: | Originally posted by Tenson
Are you suggesting using a small enclosure to give a natural LF roll-off rather than actually limiting the signal sent to the driver? |
Yes and no. Yes use a small enclosure to give natural LF roll-off AND use a filter to further limit the signal. The crossover you use depends on if active or passive. IF passive then use a 1st order highpass, if active then use a LR 4th order and if desired use a bit more volume to extend the response a little for an extended bandwidth (..but I'd target something no lower than between 300-400 Hz). BTW, the Bandor 150 (2x 8 ohm drivers per side paralleled) are the natural partners to this driver. (..baffle step "built in" and no high freq. nasty resonances and a low fs.) |
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| Jeroenkv |
I'm using Neo8 PDR's in open baffles (32 X 32 cm). Crossover is active (Thel filter, -24db) at 350hz. I also use the notch at 12khz. For bass I'm using Scanspeak 25W8567-SE woofers in sealed enclosures.
Sounds excellent!! Transparant, open and with great imaging. I'm currently not missing a tweeter (Neo3), because good response at 18khz, but 4db down at 20khz. |
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| Tenson |
| 350Hz? I am very surprised. Do you have some measurements for this system? I’d be interested to see them. |
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| Will |
| quote: | Originally posted by Jeroenkv
I'm using Neo8 PDR's in open baffles (32 X 32 cm). Crossover is active (Thel filter, -24db) at 350hz. I also use the notch at 12khz. For bass I'm using Scanspeak 25W8567-SE woofers in sealed enclosures.
Sounds excellent!! Transparant, open and with great imaging. I'm currently not missing a tweeter (Neo3), because good response at 18khz, but 4db down at 20khz. |
One man's meat is another's poison ;-) |
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| Jeroenkv |
| quote: | Originally posted by Tenson
350Hz? I am very surprised. Do you have some measurements for this system? I’d be interested to see them. |
Not that surprising, because B&G recommends a -12db filter at 400/500hz. That makes 350hz with -24db not a problem.
http://www.partsexpress.com/pdf/264-713.pdf page 5 |
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| Tenson |
You must listen VERY quietly? Do you not also find the response starts to roll-off a fair bit above that, or does the slightly large baffle fix that? With a 23cm x 23cm baffle you can see on my plots it only extends to about 700Hz.
I think we definitely have different taste ;) |
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| Jeroenkv |
| quote: | Originally posted by Tenson
You must listen VERY quietly? Do you not also find the response starts to roll-off a fair bit above that, or does the slightly large baffle fix that? With a 23cm x 23cm baffle you can see on my plots it only extends to about 700Hz.
I think we definitely have different taste ;) |
I had the same feeling when I tried it, but baffle step and the larger baffle helped to keep it flat. No dips and smooth take over by the woofer. Baffle is 35 X 35cm. My wife does not think I listen quietly.... ;)
Before this I listened to the Scanspeak Reference Monitor which is flat as possible. So my reference is o.k. |
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| Jeroenkv |
Reponse of my Neo8PDR in open baffle (all between -3db/+3db)
[IMG] [/IMG]
(Low 16khz has to do with microphone) |
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| Tenson |
| Thanks, but surely that is the applied EQ, not the actual response of the drivers? Is that a DriveRack? |
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| Jeroenkv |
| quote: | Originally posted by Tenson
Thanks, but surely that is the applied EQ, not the actual response of the drivers? Is that a DriveRack? |
You are right it is the applied EQ, so you have to invert!!
I don't use the EQ for the Neo, because it is a very flat response. I only use a Behringer DSP1124P for low channels to correct acoustics (<350hz). |
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| Tenson |
Do I take it that you targeted a flat response and told it to auto EQ?
Where did you take the measurements? Just wondering how much 'room' there is in the measurement. |
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| Jeroenkv |
| Two places. At 1 meter and at the listening position (+/- 3 meter). Listening position is leading for me (that is what I hear). |
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| cph2000 |
I have heard this unit in the Martin Logan mosaic speaker (neo8 + neo3 in a diploe with a 8" metal woofer crossing rather low at 450 Hz and 3200Hz) - it was very musical and open - a speaker I could live with !
This might just be a tricky driver to use, but it can sound good ! |
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| inertial |
Hi Jeroenkv,
Outstanding performance!!
I am surprised because my Neo8PDR measure quite different...
With a baffle 27cm wide and a big rear closed box(stuffed) mine are flat 800-5500Hz, at 400Hz = - 8 dB plus the peak at 12KHz is another
+ 8 dB. (Anechoic simulated) Good agree with BG data.
Now you are dipole and sure you have done great work with driver position/offset/baffle and also you are" in room measurement", but the difference is "suspect" to my eyes.
How much precision can have the DSP8024 ?
Anyway best two measuring more than one less! :)
Cheers,
Inertial |
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| Jeroenkv |
I have back waves coming in phase I presume?
My baffle is 1,68 times bigger (square cm), baffle step?
Baffle is 60cm from wall and toed in?
This kit uses Neo8 from 500hz http://www.audax-speaker.de/pro30d.htm (baffle 30 cm)
.....
.....
;)
Behringer is o.k. tested with other equipment.
Peak has a notch. |
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| Jeroenkv |
| Additional: Length sound wave at 300hz is 1 meter. |
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| inertial |
| Maybe 1,14mt .... ;) |
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| Jeroenkv |
| quote: | Originally posted by inertial
Maybe 1,14mt .... ;) |
divided by 4 makes........... a baffle around 30cm, to be sure 35cm! :D ;) |
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| gp4Jesus |
OK so would anyone like to take a stab @ what the BG Neo 8 might sound like in an MTM center HT speaker 9" (H) X 22"(W) or
an MTM L or R HT speaker 9" (W) X 23.75"(H)? |
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| gp4Jesus |
| Oops! I forgot to mention "screwed on to the front baffle, nothing fancy" |
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| gp4Jesus |
| any idea how the BG would sound "screwed" to the front of an 11 " high, 22" wide baffle (MTM[MBGM or W/BG/W!]) XO freq 700hz |
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| Reilumeininki |
| Anyone measured this unit after last post,new projects maybe?Before i buy these and try to get flat response for this driver I want to know:Is it really worth it? |
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| ScottG |
| quote: | Originally posted by Reilumeininki
Anyone measured this unit after last post,new projects maybe?Before i buy these and try to get flat response for this driver I want to know:Is it really worth it? |
Here are some measurements on the Neo 8 (not the PDR version):
http://www.diyspeakers.net/projects.php
In particular look at Justus Verhagen's measurements - they appear to be the most accurate and are very similar to BG's own measurements. Though its difficult to tell (because of the way the graph is displayed), they actually correlate well with Jean Claude Gaertner's series of Neo 8's. Ray Wagner's measurements however look VERY different and I wouldn't rely on them at all.
IMO its just a matter of using the driver correctly..
1. Do NOT have anything near the driver that would impead air flow, chances are this means open baffle - BUT that isn't neccesarily so.
2. Look at the driver's off-axis performance to determine the listening axis. For the standard Neo 8 thats about 45 degrees off of the driver's primary axis. Do NOT be fooled by the off-axis (45 degree response) response at higher freq.s - the driver should have plenty of high freq. response due to in-room spl and linesource radiation character (..though this wouldn't be the case if you listened in the near field).
3. Judge how you will integrate another driver carefully. IF you want to use the Neo 8 down to lower freq.s then you will likely need a shelving circut that cuts the response from about 2.5 to 12 kHz. If you want to use a mid/woofer much higher up then consider the -3db point around 1.8 kHz and design appropriatly for that dip in spl.
4. Recognize that how you load the driver will alter its freq. response - particularly below 2 kHz. In this case if you don't like the rising response near resonance then pehaps consider an open baffle that is a little less wide (to start the dipole loss in spl a little higher in freq. response). A program like the Edge can help here with that (..even though it spec's a round driver).
http://www.tolvan.com/edge/
With a minimum of effort and build complexity I think you could come up with something that was quite good with the Neo 8. |
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| Jeroenkv |
I use the Neo8PDR in an open baffle but not to wide. This works very well!! Wider baffles give problems at the lower end. Crossover is around 800hz. I use the notch for the high end.
My experience is also that off axis measurements tell more about performance in a listening situation.
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| Reilumeininki |
Yep, Off axis measurements (30 and 60 degree angle)is to me important part when designing speaker, every situation.Even if it is small 2-way or tall 3-way and typical 1"dome and 4-6" low/mid cone.Bigger than 6" i use waveguides to domes to handle side response.
Jeroenkv:Looks great.More information about that(measurements)?
So you think that Neo 8 is worth it?;) |
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| Jeroenkv |
| The thing with the Neo8PDR is that you have a bump on-axis at 12khz (even with notch), but this is fine because it gives a flatter response from 15 degree angle up. It is just more sensitive than normal tweeters, because they "beam" more. |
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| Samppo |
I've used the Neo8 for a couple of years now crossed over to an 8" midwoofer in an open baffle configuration. Sounds good to me!
Wouldn't worry too much about the 12khz hump as it's really not there with music |
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| gp4Jesus |
hey Samppo
Passive? what did you use for an XO? Active? What XO slopes and freqs? I can go either way because I already have the amps, etc.
How about a decription or pic of the Neo "baffle?" Pardon my ignorance, I don't know exactly what open baffle means.
I'm researching using a Neo 8 in an MTM with 7"s*, plus subs**, in a Home Theatre app. 3*** as described. Left, center, & right, active; rears, and eventually sides, TM, passive. When I have all 5 channels working to my satisfaction and if 7 channel HT takes hold of the market I'll up grade my SSP and build 2 more passives.
* elsewhere in this forum
** active, in use for 15 years
*** I have a Rotel 5 ch SSP; at least that's what I'd like to do
thanks
tony |
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| Samppo |
Tony, i've been using the Neo8 with a behringer dcx-2496 active crossover. Crossover points have varied all the way from 1000-1500hz with different slopes, it's so easy to experiment with the dcx.
Now I'm using them at 1200hz with 12 db filtering. In the beginning i also tried a waveguide for the front beam, but it didn't really work that time, but i'm going to try it again soon with some better horn shape.
Open baffle (or dipole) means having no box - the driver is only attached at the top and bottom and open at the sides and back. Sorry have no picture at the moment. |
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| gp4Jesus |
| quote: | | Open baffle (or dipole) means having no box - the driver is only attached at the top and bottom and open at the sides and back. |
another dumb question: simply attaching the Neo 8 to the front baffle is NOT OB?
I saw mention of a Neo 10 in another thread. Know anything about it?
TOny |
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| Samppo |
gp4jesus: good you asked, my error - open baffle criteria is that a speaker driver can freely distribute sound to the front and back, without any enclosure at the back trapping the sound. It's only in my configuration the Neo8 is fastened at the top and bottom.
If you want pure dipole function the front baffle can't be too wide - especially going higher up in frequency.
The Neo10 could be an interesting driver, there's just not much information about it. As far as i know, it's not for sale as a separate driver |
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| gp4Jesus |
so I could attach* it to the front baffle of my enclosure?!
*unglamourously with 4 screws (LOLLOLLOL)
of course the response will be affected. any speculation?
on the Neo 10: you say not much info available. I'd go some extreme to get it.
Thanks
Tony |
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| ashok |
Does anyone know the URL of the web page where they the had open baffle response of a Vifa P13W... with various sizes of baffle including the effect of the angled wings.
Thanks.
Ashok. |
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| Daveis |
Does anyone have speaker THD measurement capabilities, and could measure the BG drivers Neo8 and RD series?
Maybe show 2nd, 3rd, 4th, 5th harmonic THD???
I am wondering how they compare to Seas/Scanspeak midrange... |
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| ears4hire58 |
| quote: | Originally posted by gp4Jesus
so I could attach* it to the front baffle of my enclosure?!
*unglamourously with 4 screws (LOLLOLLOL)
of course the response will be affected. any speculation?
on the Neo 10: you say not much info available. I'd go some extreme to get it.
Thanks
Tony |
I am new to this group. Last I heard from BG, they are keeping the Neo 10 in house.
For the last few years I have been working (on the side) with the companies that make the largest push-pull magnetic-planar drivers available (some even bigger than the Neo 10), trying to bring then to the specialty live-sound market.
FPS of Japan www.fps-inc.co.jp has just released the latest upgrade of their FPS1030(M3F1R1) 6x14" planar drivers. I should get my hands on the 1st. pair brought into the country in a few days. They also make 10x14" planar drivers. I have spec sheets, but I will just attach a photo of a small FPS planar driver (exploded) for now.
I have been working on MTM speaker designs based on these med. and large planar drivers as the mid. drivers (& planar HF from any of several other sources), as well as designs based on planar drivers from the other leading sources. |
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| Daveis |
Ears,
How did you get your hands on some samples? Are they expensive?
Had a chance to compare those FPS1030(M3F1R1) to any of the BG's drivers (Neo or RD series)? |
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| ears4hire58 |
| quote: | Originally posted by Daveis
Ears,
How did you get your hands on some samples? Are they expensive?
Had a chance to compare those FPS1030(M3F1R1) to any of the BG's drivers (Neo or RD series)? |
I do contract consulting and marketing work for some of these driver companies.
The samples are in a few locations right now. I should have them all in the same room to compare by month end.
I will post more on the FPS planar drivers in a new thread. |
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| ears4hire58 |
| quote: | Originally posted by ears4hire58
I do contract consulting and marketing work for some of these driver companies.
The samples are in a few locations right now. I should have them all in the same room to compare by month end.
I will post more on the FPS planar drivers in a new thread. |
I posted more info. on the new FPS planar drivers in the exsisting FPS planar thread |
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