You guys can pick whatever name you wantIt is sort of a placebo though, in that it is a box providing some bass with no driver...
No, there's a driver, it's just not attached to the resonator. It works just like a guitar and you don't call them placetars. "Placebo" means it works just because you think it will work and that's not the case at all here.
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No, the resonator is actually providing useful output. There's no doubt about that.
Of course not. If the resonator wasn't doing anything that speaker on that baffle would sound much much worse than your average clock radio. I don't believe the marketing claims per se but I doubt it's that bad. I'm sure the inventor isn't the only one that's ever heard them, and I haven't heard any reports that they are completely unlistenable.
I'm right there with you. As I said before, I want to try this setup myself. I'm not one of those guys that says that everything in audio has all been done before and there's no such thing as a "new" anything and the only difference is that modern drivers are far superior. I'm also not one of those guys that will let the inventor off the hook for being his own biggest fan and talking about himself in third person. But my humor doesn't exactly go over well when I try too hard. Unbox? Placeebox? Funny, right? Yeah, I know, it's not that funny...
BTW, I built his Wicked One design for a pair of 8 inchers just a little while ago. High output as advertised, but I didn't realize the true enormity of the enclosure until after I started building it and found it to be unusably large. Nonetheless, my poking fun at him is not meant to be contemptuous as I believe in his ability to design a functioning product. I'm just not going to stick a microphone in it and then take that signal...
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ok i have done some simple listening tests. Not good subjectively.
As per picture when the boxes are added, there is an overall loss of top end air and detail taking away from focus and presence to vocalists. This gives the impression of more smoothness, however, the life and soul seems to have gone from the music. There was also an apparent abberration to the tonal spectrum giving male voices a somewhat less than recognisable natural feel. I was not aware in my short listening period of any increase in low bass output, or extension. I elevated the boxes so they rested on ebony pucks, again this made no difference to the overall effect. I then decided to replace them with weights of marble and graphite, to see if it was the added mass that was having these effects, and got a similar loss of top end detail and focus but without the tonal abberrations. These open baffles hate any kind of mass added to them, and indeed a lot of the life and excitement in the music needs this sort of 'loose fixation to its surroundings'. This was further confirmed when i added air supports to the base of these speakers as described on my own thread.
It will be interesting to hear when someone does the proper full implementation of this methodology, as there was a horn effect added to the design which my simple box does not have. Any suggestions for further experimentation would be welcomed short of having to do the full original design which i neither have the time or inclincation with my present findings.
As per picture when the boxes are added, there is an overall loss of top end air and detail taking away from focus and presence to vocalists. This gives the impression of more smoothness, however, the life and soul seems to have gone from the music. There was also an apparent abberration to the tonal spectrum giving male voices a somewhat less than recognisable natural feel. I was not aware in my short listening period of any increase in low bass output, or extension. I elevated the boxes so they rested on ebony pucks, again this made no difference to the overall effect. I then decided to replace them with weights of marble and graphite, to see if it was the added mass that was having these effects, and got a similar loss of top end detail and focus but without the tonal abberrations. These open baffles hate any kind of mass added to them, and indeed a lot of the life and excitement in the music needs this sort of 'loose fixation to its surroundings'. This was further confirmed when i added air supports to the base of these speakers as described on my own thread.
It will be interesting to hear when someone does the proper full implementation of this methodology, as there was a horn effect added to the design which my simple box does not have. Any suggestions for further experimentation would be welcomed short of having to do the full original design which i neither have the time or inclincation with my present findings.
As far as you know. At least, that's what the previous 67 post are leaning towards.
From there discription : Driver complement 1 DFR-8S
This driver is likely the fe207E with a phase plug and a new surroud. Well they list
the sensitivity of the driver at 96 db with a qts of .23 so how do they get 99db/w
out of a driver rated at 96db/w?
I am tempted to buy a set of them after all they have a mony back guarentee .......
Yes I think I will do that as soon as that dead beat cousin pays me back that money I loned hem 3 years ago....
This driver is likely the fe207E with a phase plug and a new surroud. Well they list
the sensitivity of the driver at 96 db with a qts of .23 so how do they get 99db/w
out of a driver rated at 96db/w?
I am tempted to buy a set of them after all they have a mony back guarentee .......
Yes I think I will do that as soon as that dead beat cousin pays me back that money I loned hem 3 years ago....
I've now build the Decware ZOB with the recommended DFR8s drivers.
This is indeed a very special loudspeaker/concept. I can agree to most of Steve claims about them. But they don't give the bass response I had expected and I'm used to open baffle bass drivers so it's not the boomy bass I'm looking for in the ZOB.
Today I started to figure out why they are a bass shy. The adjustable slot has major impact on the amount of bass coming out of the box and extreme care must be taken into account that both speakers had been adjusted in the same way.
Even small adjustments make a huge difference in the output.
I had measured as much as 20dB difference within a few millimeters adjustments.
I'm not done with my research and I've to change the material I used between the box and the baffle to insure that they are perfectly airtight.
Meanwhile I've cheated and used the equalizer in Foobar (the mediaplayer I use for my DIY USBDAC) to get a flat response down to around 50 Hz.
Now we are talking! With this compensation this loudspeaker reveal the very best loudspeaker I've heard in my 27 years as audiophile. LOL!
So cheap a speaker and so very high performance but for now only with the compensation in the bass region. One of these days I'll make a BSC-network as I need the speakers for other sources than Foobar.
So in this open baffle concept the modified Fostex 207E sounds a lot better than any other FR driver I've heard (e.g.: Lowther, AER, BD-design, Planet10 FE127eN, Coral Flat8, Coral Beta8, Hørning Hybrid; all heard in non open baffle speakers). Wow! :-D
I'm deeply impressed.
I'll be back later with measurements and more.
This is indeed a very special loudspeaker/concept. I can agree to most of Steve claims about them. But they don't give the bass response I had expected and I'm used to open baffle bass drivers so it's not the boomy bass I'm looking for in the ZOB.
Today I started to figure out why they are a bass shy. The adjustable slot has major impact on the amount of bass coming out of the box and extreme care must be taken into account that both speakers had been adjusted in the same way.
Even small adjustments make a huge difference in the output.
I had measured as much as 20dB difference within a few millimeters adjustments.
I'm not done with my research and I've to change the material I used between the box and the baffle to insure that they are perfectly airtight.
Meanwhile I've cheated and used the equalizer in Foobar (the mediaplayer I use for my DIY USBDAC) to get a flat response down to around 50 Hz.
Now we are talking! With this compensation this loudspeaker reveal the very best loudspeaker I've heard in my 27 years as audiophile. LOL!
So cheap a speaker and so very high performance but for now only with the compensation in the bass region. One of these days I'll make a BSC-network as I need the speakers for other sources than Foobar.
So in this open baffle concept the modified Fostex 207E sounds a lot better than any other FR driver I've heard (e.g.: Lowther, AER, BD-design, Planet10 FE127eN, Coral Flat8, Coral Beta8, Hørning Hybrid; all heard in non open baffle speakers). Wow! :-D
I'm deeply impressed.
I'll be back later with measurements and more.
This is something that has bothered me for as long as I've been in this hobby. I don't know why. Somehow I think it degrades the SQ. But if you are happier with the sound, what's the big deal? (I tell myself)
So I run Foobar with maximum cut at 20khz and 1/2 cut at 15khz and it's great. But it still feels like cheating; like a bandaid fix.
(Edit) My foobar stops at 50hz on the analyzer and 55 on the EQ. Why is this? It should go to 20. Does anyone know why?
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not i do know why, but it's just plain true. that's why you should give a try to vst EQ minumum (free here: http://www.aixcoustic.com/index.php/Electri-Q-posihfopit/30/0/)
or even better linearphase dsp sound so much more trasparent that it's easily clear on quick a/b comparison
get rid of that built-in eq that comes with foobar itunes, system drivers or whatever and go DSP
Nelson bass i think this also apply to your new speakers, also what kind of eq are you applying? only bsc? bass boost? how much?
Agree the EQ should go at least down to 20 Hz. I don't know why as well.This is something that has bothered me for as long as I've been in this hobby. I don't know why. Somehow I think it degrades the SQ. But if you are happier with the sound, what's the big deal? (I tell myself)
So I run Foobar with maximum cut at 20khz and 1/2 cut at 15khz and it's great. But it still feels like cheating; like a bandaid fix.
(Edit) My foobar stops at 50hz on the analyzer and 55 on the EQ. Why is this? It should go to 20. Does anyone know why?
I'm pretty happy with the equalizer within Foobar as far as SQ goes. How can it possible degrade the sound? They upsample the data to a higher bitrate before any signal handling within Foobar. Therefor the volume control also must be way better than the volumecontrol in Windows? And properly also better than a pot in the analog domain?
Back to the thread topic. I've now sealed one of the ZOBs and will now listen to it (the other speaker disconnected and signal in mono - yes I can hear the grass grow so if anything is changed soundwise I'll measured it afterwards).
BTW... the reason for the speakers being bass shy can be the fact that I for now use a chip amp instead of a recommended tube amp (my PP1CS is on the mod table right now).
Hi Nelson,
Have you had a chance to take some measurements?
I have some fe207E's laying around and might have a go of this design in the future. Im considering using a parametric eq to boost the low end and perhaps a sealed sub. Would you say this is worth persuing?
Oh oh i may have to run parallel projects, busy weekends, the girl wont be happy
Hi Dabbler,
I've listened to a lot other speakers lately. With fresh drivers in the ZOB they just sound thin in my ears. Not a little thin but thin. Listening fatigue is another issue with this driver in my system at least. I can't stand it for more than 30 minutes. So I've no leave the room to break in the drivers...
Steve Deckert just wrote in the support forum that the drivers really needs some hours on them to give some bass output. Furthermore Steve is suggestion some stuffing the chamber to make the Q wider.
I've only made some initial measurements and it's very hard to make measurements below 300 Hz in a normal listening room...
I've used the eq in my Foobar to balance the driver and the bass and it turns out very well this way. A good way to break in the drivers as well IMO.
With the balanced frequency response I found this speaker very very good if you don't need to impress friends with deep and loud bass thundering shaking your house.
The balanced speaker sound very very coherent and effortless. Vocals and acoustic instruments sound natural. There are details in spades and the imaging is on par with the best I've heard.
That said I found my own CS2 clone and the DTQWT by Troels Gravesen to be way more dynamic and true to the size of acoustic instruments.
But this is not my final statement about the ZOB. I'm about to build a pair of HDTs and I want to spend some time on the broad cast system as suggested by Steve Deckert.
But the time is limited at the moment as I want to upgrade my Emerald Physics CS2 clones to CS2.3 status and nothing less than 4 amplifier projects...
So be patient for an update and look at the Decware Support forum for other builders feedback.
I've listened to a lot other speakers lately. With fresh drivers in the ZOB they just sound thin in my ears. Not a little thin but thin. Listening fatigue is another issue with this driver in my system at least. I can't stand it for more than 30 minutes. So I've no leave the room to break in the drivers...
Steve Deckert just wrote in the support forum that the drivers really needs some hours on them to give some bass output. Furthermore Steve is suggestion some stuffing the chamber to make the Q wider.
I've only made some initial measurements and it's very hard to make measurements below 300 Hz in a normal listening room...
I've used the eq in my Foobar to balance the driver and the bass and it turns out very well this way. A good way to break in the drivers as well IMO.
With the balanced frequency response I found this speaker very very good if you don't need to impress friends with deep and loud bass thundering shaking your house.
The balanced speaker sound very very coherent and effortless. Vocals and acoustic instruments sound natural. There are details in spades and the imaging is on par with the best I've heard.
That said I found my own CS2 clone and the DTQWT by Troels Gravesen to be way more dynamic and true to the size of acoustic instruments.
But this is not my final statement about the ZOB. I'm about to build a pair of HDTs and I want to spend some time on the broad cast system as suggested by Steve Deckert.
But the time is limited at the moment as I want to upgrade my Emerald Physics CS2 clones to CS2.3 status and nothing less than 4 amplifier projects...
So be patient for an update and look at the Decware Support forum for other builders feedback.
Short answer: Yes
Longer answer: But the bass is lacking in my system so they are not as balanced as I'm used to (this can be fixed with an equalizer as in Foobar). But no matter what they will never have the same power as two 15" bass drivers. Never. Not even close.
For lighter acoustic music the ZOB can get away without bass augmentation.
But are you into Pink Floyd, Roger Waters and the like they will come out thin, thin & thin.
So for me at least I need bass augmentation to live with this speaker.
But let's see how much driver break in will help and some stuffing of the chamber.
Great reports Nelson! Good on you for taking this build on, and hearing first hand with the recommended Decware modded drivers what it's all about, so an apples to apples comparison save the amplification.. Sounds like the low end definitely needs to be augmented with these cabs, which one doesn't really get a sense of reading Steve's report at his site.. Not sure how the $2795 price tag for these cab's made by Decware really fit's, considering what it only is etc?
Thank you for your efforts and for sharing your findings!
Thank you for your efforts and for sharing your findings!
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