I think Ingvar and others have revealed enough to get a basic idea of what's going on.
I was skeptical at the beginning of the thread but it sounds like a nice compact 2-way or its at least well thought out.
- Ported enclosure (tuning frequency and alignment not revealed)
- Crossovers are non-textbook operating in a 2-7Khz overlap region. I'd assume this is to match acoustic rolloff but nothing confirmed.
- Clean baffle diffraction characteristics shown with pulse response measurement.
- Application specific 5.5" driver(4" radiating area) tuned to yield low (30hz claimed) response in-room when setup correctly.
- Some designs take advantage of diffraction used to widen the dispersion pattern of the tweeter in a particular direction ie. up
I was skeptical at the beginning of the thread but it sounds like a nice compact 2-way or its at least well thought out.
I agree with pinkmouse, calm down......
After lurking some Swedish forums there seem to be a large crowd of "followers" as seen here by the recent "Swede invasion". I think Ingvar does something special with the box damping that may be unique, but everything seems somewhat secret.
Btw, I've registered my interest for an audition of Ingvar’s speakers, I hope it will take place sooner than later. I'm skeptic by nature but open for pleasant surprises.
After lurking some Swedish forums there seem to be a large crowd of "followers" as seen here by the recent "Swede invasion". I think Ingvar does something special with the box damping that may be unique, but everything seems somewhat secret.
Btw, I've registered my interest for an audition of Ingvar’s speakers, I hope it will take place sooner than later. I'm skeptic by nature but open for pleasant surprises.
Howdy folks, I heard the smaller Guru speakers at Stereophile's NY show last summer and walked away quite impressed. As I walked into the overheated, packed hotel room, Muddy and Buddy were holding court at medium loud levels with no sense of strain or fuss. The bass was pretty clean and tight for such a small speaker and the imaging was precise if a bit lacking in depth. Given the vicissitudes of setting up thousands of dollars worth of audio gear in hotel rooms, Guru made a fine showing!
ShinOBIWAN said:
I agree. It looks like a reasonably well designed small 2-way.
It would be nice if someone was a bit more forthcoming with details, like most people are on DIY sites. Terms like Helmholtz Resonator cover such a large range of options. All we can assume is that is, as you say, a slot ported tuned cabinet.
And saying a cross-over is 2-7K really does leave a lot of open space !!! Being a 16mm tweeter( I think that's what it said), I would guess an x-o point of 4.5k (bit high for my liking) with equal shallowish rolloffs either side.
Maybe a modelled frequency response showing roll-offs of mid and tweeter would clear up that issue?
I think your last point applies more to the 8" floor stander, as the 5.5" speaker does not have the shelf on the front.
Hello Andy, I seem to remember that the Guru was ment to be placed fairly close to the rear wall for flatest bass response.
tc-60guy said:
Yep tuned low, as someone said.
Being it is actually what most would refer to as a 5" or 5.5", the 30Hz claim doesn't seem so much of a stretch in that situation.
my headphones go even lower than 30hz 😀
without spl and distortion numbers, 30hz is pretty meaningless.
without spl and distortion numbers, 30hz is pretty meaningless.
MaVo said:
yes, definitely information lacking.
I'd actually be interested in seeing Ingvar's basic x-o layout. I wonder if he could provide a simple sketch with strategic bits removed, no numbers etc.
I'm still very much up in the air by what he means when he says "Non-textbook functions". Does he , for instance, mean that his x-o doesn't use textbook calculations. Or does he mean that he has achieved roll-offs that are intrinsically "new". If so it would certainly be interesting to see, even if only on a modelled response graph.
NP: Bela Fleck: 20th Century: Track; Flight of the Cosmic Hippo
tinitus said:
"I made a speakers like the 2way floor model 10years ago and sure, its a nice concept if you can get an 8" to play decent midrange....
Okay, how did your speakers in your opinion compete with design such as B&W 801 or 802?
The 8" you were using, was that mid/woofer used as is from the store, or was it altered in some way?
"I made a speakers like the 2way floor model 10years ago and sure, its a nice concept if you can get an 8" to play decent midrange....
Okay, how did your speakers in your opinion compete with design such as B&W 801 or 802?
The 8" you were using, was that mid/woofer used as is from the store, or was it altered in some way?
theonlyone said:
Hi, I think they were(are) compareable to older B&W805, well maybe a bit better...I dont know the new B&W
A younger famely member is listening to them now. He wants something new now, but hasnt been able to find anything yet 😀
I used an older Seas Excel W21EX-001, paper cone with copper phase plug...tweeter was Thiel C22
It was all "leftowers" that was intended fore a bigger project that never made it
Today I may be able to get even better sound out of them, but the lad has decided that I will have to build something new...or maybe its his wife
I also made him some LCAudio amps...so I suppose I gave him a good start in the world of music listening, which makes me quite happy 🙂
Hi tinitus,
I've listen a lot to those woofers, excellent midrange. They put many smaller midwoofers midrange performance into shame.
I've listen a lot to those woofers, excellent midrange. They put many smaller midwoofers midrange performance into shame.
They had a demonstration of these at the Minnesota Audio Society club meeting. They required a wall to work against, but sounded pretty good. However, they failed to play complex low frequency bass passages with clarity. e.g. the stand up bass on erykah badu (track name escapes my mind, but off baduism). They played the bass from a couple of dance tracks really well, and while I enjoyed them I wouldn't pay that kind of money.
Its pretty close to what I use with a SS 15W and XT25 in 3way...RC and notch needed, otherwise its just a rather small series inductor
I guess it could be done in a 2.5way too
Dave, whats that about...what is this new interest in crossovers 😀
I guess it could be done in a 2.5way too
Dave, whats that about...what is this new interest in crossovers 😀
planet10 said:
yeah, but you like to use a full range driver
with a high crossed small tweeter and a sub. 
:
shallbehealed said:
This is what I would have expected.
And bass on "dance" tracks is usually around 50-70Hz, so it shouldn't be an issue for a corner positioned 5" driver at normal(ish) listening levels.
An observation.............
This post was not started by the designer of these speakers or his colleagues , so it "might be possible " that they do not have to disclose ANY details at all !! Especially to non potential buyers and unknown people ?
Looking back at the posts it seems funny that a lot of posts were piling up on the designers for not revealing ALL . Are they required to do that even if they didn't start the post ?
Am I missing something ?
Maybe it just went out of control earlier and I see it's getting back on track now..............😀
This post was not started by the designer of these speakers or his colleagues , so it "might be possible " that they do not have to disclose ANY details at all !! Especially to non potential buyers and unknown people ?
Looking back at the posts it seems funny that a lot of posts were piling up on the designers for not revealing ALL . Are they required to do that even if they didn't start the post ?
Am I missing something ?
Maybe it just went out of control earlier and I see it's getting back on track now..............😀
I have tried to find out how Oehmans speaker works and the construction behind, just to use it in my own DIY designs. Many of the things are not very hard to find out at all, others are quite confusing.
This is my wiew, in other words there might be some speculations and misunderstandings.
The crossoverpoint is selected so you get a linear respons in the reflection from the ceiling, this is a simple task overseen by most DIY designers. You trade a little bit of sweetspots heigth, but gain in response of the reflection from the ceiling. Oehman has positioned tweeter and woofer close to each other and this makes the crossover frequecy pretty high if you want to achive thing mentioned above.
I think crossover in the smaller speaker is assymetric otherwise you couldn’t get a nice in phase transition around the crossoverpoint. This means that crossover topology is rather usual wihtout delay links.
I dont know the slopes order, but they are dependent of the acostical center in the crossover zone of the selected drivers. The difference to our DIY speakers is that he knows how to make speakers with an in phase transition not just in small angle around the horisontal plane of the sweetspot but to the speakers extreme angles. Sometimes however our DIY speaker has this feature but we dont know exaktly why (Ok I do know and some others too).
All this means that the smaller speaker is not able to reproduce that pulse Oehman showed but the bigger one makes the trick.
I think many of us have used the old SEAS P17RCY, did you remember it off axis behaviour. Dispersion was pretty amazing. Oehman have taken his drivers in that direction and pushed them even a bit further, they have in other words a very good dispersion at higher frequency. The 8 incher is specified up to 6 kHz +-1 dB (must be onaxis) this is not an off the shelf product as you can understand. It’s just the basket of the speaker thats common production stuff. When we must go 3-ways Oehman can do it with a 2-way design. (Ok, some of us just do this with a single driver.)
The bigger model uses a “transient perfect” crossover and therefor it is able to reproduce a pulse like the one showed by Oehman. Crossover slopes are rather steep.
Oehman has made small adjustments of the onaxis response, it’s not a BBC-dip but a compensation of the problem that arises when making a phantom projection in between the speakers using sound sources about +-23 degrees apart. I think the adjustment is very small if you compare with the BBC-dip. Just a speculation, this kind of compensation could be done with baffle design. I think this is why he uses a rather simple baffel design making it possible to calculate the behavior.
I hope this will ligthen up a little bit, anyway it’s all about physics.
BR
/Gunnar
This is my wiew, in other words there might be some speculations and misunderstandings.
The crossoverpoint is selected so you get a linear respons in the reflection from the ceiling, this is a simple task overseen by most DIY designers. You trade a little bit of sweetspots heigth, but gain in response of the reflection from the ceiling. Oehman has positioned tweeter and woofer close to each other and this makes the crossover frequecy pretty high if you want to achive thing mentioned above.
I think crossover in the smaller speaker is assymetric otherwise you couldn’t get a nice in phase transition around the crossoverpoint. This means that crossover topology is rather usual wihtout delay links.
I dont know the slopes order, but they are dependent of the acostical center in the crossover zone of the selected drivers. The difference to our DIY speakers is that he knows how to make speakers with an in phase transition not just in small angle around the horisontal plane of the sweetspot but to the speakers extreme angles. Sometimes however our DIY speaker has this feature but we dont know exaktly why (Ok I do know and some others too).
All this means that the smaller speaker is not able to reproduce that pulse Oehman showed but the bigger one makes the trick.
I think many of us have used the old SEAS P17RCY, did you remember it off axis behaviour. Dispersion was pretty amazing. Oehman have taken his drivers in that direction and pushed them even a bit further, they have in other words a very good dispersion at higher frequency. The 8 incher is specified up to 6 kHz +-1 dB (must be onaxis) this is not an off the shelf product as you can understand. It’s just the basket of the speaker thats common production stuff. When we must go 3-ways Oehman can do it with a 2-way design. (Ok, some of us just do this with a single driver.)
The bigger model uses a “transient perfect” crossover and therefor it is able to reproduce a pulse like the one showed by Oehman. Crossover slopes are rather steep.
Oehman has made small adjustments of the onaxis response, it’s not a BBC-dip but a compensation of the problem that arises when making a phantom projection in between the speakers using sound sources about +-23 degrees apart. I think the adjustment is very small if you compare with the BBC-dip. Just a speculation, this kind of compensation could be done with baffle design. I think this is why he uses a rather simple baffel design making it possible to calculate the behavior.
I hope this will ligthen up a little bit, anyway it’s all about physics.
BR
/Gunnar
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