Hans:
Any chance you can post the distortion measurements for the R2904? I searched the web for hours but never found anything relatiing to distortion measurements. Personally I don't know of anyone from the various forums around the world that's seen a distortion measurement for the R29, so I'm sure you'll be doing a service to other too if you show the data. I've even emailed SS to see if they have any data but haven't heard back from the yet.
Although I am going to start my experiments at 3Khz, nobody here has provided definitive evidence that the R2904 can or cannot be used low in the XO. Some seem to basing opinions on published specs for a different driver - the XT and other provide no evidence other than no evidence at all.
I think what I'll do is just experiment, I can't measure the distortion but I can obviously tell what sound good and bad (to me). So I'll give the 1.5Khz and 2Khz a try to see if I can disprove or approve some of the opinions on here.
Any chance you can post the distortion measurements for the R2904? I searched the web for hours but never found anything relatiing to distortion measurements. Personally I don't know of anyone from the various forums around the world that's seen a distortion measurement for the R29, so I'm sure you'll be doing a service to other too if you show the data. I've even emailed SS to see if they have any data but haven't heard back from the yet.
Although I am going to start my experiments at 3Khz, nobody here has provided definitive evidence that the R2904 can or cannot be used low in the XO. Some seem to basing opinions on published specs for a different driver - the XT and other provide no evidence other than no evidence at all.
I think what I'll do is just experiment, I can't measure the distortion but I can obviously tell what sound good and bad (to me). So I'll give the 1.5Khz and 2Khz a try to see if I can disprove or approve some of the opinions on here.
If you are going to try 1.5khz then I would suggest not turning it up much, the scan RR does not have a huge amount of linear excursion and due to its smaller radiating area will have to move more then a normal 1" dome, thus adding to the increased excursion at lower frequencies. The radiating area is only 1cm2 more then some 3/4" domes.
This is just a precautionary warning I dont want to see you kill £500 of tweeters by mistake.
This is just a precautionary warning I dont want to see you kill £500 of tweeters by mistake.
5th element said:
Yep I'm still with the 3Khz personally but for curiosity/arguements sake I'd like to see what the sound is like with the lower XO points.
Also it goes without saying that I'll be incredibly vigilant with volume during all testing.
Won't really be able to post these results for some time yet but when I do I'll be sure to come back with subjective opinions on my findings.
Also after a rather exhaustive search I've failed to come up with a suitable mid/bass. So I'm now looking at 3-way. Thinking along the lines of an ATC 'Super' dome mid or Seas M15CH with possibly a Volt or Seas Excel Bass unit.
Also...
Whilst looking around on the web I found the Von Schweikert VR-11, VR9 SE and VR7. Its interesting to note that all these designs use the Scan Ring. But I would be interested to find out what midrange driver these use. Its described as a french made 'aerogel' unit so is this an Audax unit? If so there not much chance of getting hold of one since they stopped selling to the DIY community a while ago.
Any opinions on the brand of this driver?
ShinOBIWAN,
the German speaker-builder magazin has published distortion-measurements versus voltage for the SS Ring at 1500Hz. K2 exceeds 1% at 1V but K3 is below 0,01% up to 1V and rises to only 1% at 20V! K5 has 0,3% at 20V. With the SS Ring distortions are nothing to worry about, only K2 reaches higher levels while K3 and K5 are close to unbeatable low over the whole frequenzy range. In the magazin they recommend 1500Hz as XO frequenzy for high SPL and min 1000Hz in small 2-way systems with low max SPL.
With 4th order filtering 1500Hz should be absolutely no problem but i would try 2000Hz to keep the tweeter secure at very high soundlevels. K2 doesn´t affect soundquality as much as K3 and K5. Only distortions over 1% are audible.
Audax chassis are available in Germany but if you can afford it go with the ATC SCM75-150S for midrange. In this case you could rise the XO point up to 2500-3000Hz as the ATC will perform perfect up to this frequenzy. But in 2-way sytems the Ring will simply sound better at 2000Hz then a 7" mid/woofer. Also dispersion of an 7" chassis is really poor at 3000Hz. The ATC will also match very good with the Ring in the way they sound. Very high resolution without any harshness.
My Ring has survived excursions of more than 4mm while it was accidentally connected to the amp instead of the woofer during impedance measurements. So you see it´s not really easy to kill this tweeter.
The 18W8531/G00 like in the Ultimo will be a good choice for a 2-way system. I´ve got 2 pairs to sell if you´re interested.
illusionxx.
the German speaker-builder magazin has published distortion-measurements versus voltage for the SS Ring at 1500Hz. K2 exceeds 1% at 1V but K3 is below 0,01% up to 1V and rises to only 1% at 20V! K5 has 0,3% at 20V. With the SS Ring distortions are nothing to worry about, only K2 reaches higher levels while K3 and K5 are close to unbeatable low over the whole frequenzy range. In the magazin they recommend 1500Hz as XO frequenzy for high SPL and min 1000Hz in small 2-way systems with low max SPL.
With 4th order filtering 1500Hz should be absolutely no problem but i would try 2000Hz to keep the tweeter secure at very high soundlevels. K2 doesn´t affect soundquality as much as K3 and K5. Only distortions over 1% are audible.
Audax chassis are available in Germany but if you can afford it go with the ATC SCM75-150S for midrange. In this case you could rise the XO point up to 2500-3000Hz as the ATC will perform perfect up to this frequenzy. But in 2-way sytems the Ring will simply sound better at 2000Hz then a 7" mid/woofer. Also dispersion of an 7" chassis is really poor at 3000Hz. The ATC will also match very good with the Ring in the way they sound. Very high resolution without any harshness.
My Ring has survived excursions of more than 4mm while it was accidentally connected to the amp instead of the woofer during impedance measurements. So you see it´s not really easy to kill this tweeter.
The 18W8531/G00 like in the Ultimo will be a good choice for a 2-way system. I´ve got 2 pairs to sell if you´re interested.
illusionxx.
"Only distortions over 1% are audible."
Yea right!
1V and 1% is totally unacceptable for a high performance design. What do you think happens when a zillion of tones are playing simultaenously with music at typicall levels?
Whats the 2nd order distortion at higher level?
High 2nd order distortion is not ok since the intermodulation products will be all over the place when playing music.
/Peter
Yea right!
1V and 1% is totally unacceptable for a high performance design. What do you think happens when a zillion of tones are playing simultaenously with music at typicall levels?
Whats the 2nd order distortion at higher level?
High 2nd order distortion is not ok since the intermodulation products will be all over the place when playing music.
/Peter
Hans L said:I do not base strong opinions on the words of others. LDSG is a very helpful resource, nothing wrong with it. It's the first advice I give to newbies entering speakerdesign. But like all subjective sources, it's not the say all be all of speakerdesign.
I do... That's why I permit myself to say 'they don't even compare below 2.0KHz.' Or do you think I'm making this up while I'm typing?...
K2 for a ringrad is always relatively high compared to higher order non linear distiortion products. This is a well known fact and relates to the construction of a ringrad, which is essentially a surround without the dome.
I have heared two two-way designs, a 3-way design and have had the opportunity to tweak the xo in a scan speak Ultimo via LspCad pro's emulator. I think I know what the tweeter can or shouldn't be doing.
So far it seems you are basing you opinion on Scan speak's specsheets and you seem to be more interested in my credentials than the Scan Speak ringrad's potential. You may now kiss my
bottom.
Oh this is just tooooooo easy to pick a-part..
I have provided my basis (and thats kind'a the point, but it appears to be something you have difficulty with). Yes I am basing my opinon on Scan Speak's spec sheet as well as their reputation for advanced motor design (providing lower levels of distortion) - DUHHH (having said so..). I don't give a rat's as-s what your credentials are - however if you think providing support for your opinions = credentials, then yes I do care about your "credentials".
My problem wasn't with your strong "opinion", but rather that your strong "opinion" was tantamount to fact - AND that you gave either no tangible basis for your opinion or that the basis given was so "thin" as to be nothing more than an iteration of your opinion.
Whats "thin" support?:
1. the LDSG reference to a higher cross-point, which as I explained b4 has NOTHING to do with why you based the driver as being unusable at freq.s at or below 2kHz..
2. A. You did not say that you had personal knowledge of the drivers's distrotion characterstics. (and even if you did..)
B. You did not give ANY information as to what the distortion figures were (nor have you now - is it that difficult?). Do I think your making it up? I don't care (it would be nothing more than a wasted guess), BUT the information's (easily provided) absence lends ABSOLUTELY no credibility to your "strong" opinion.
3. the increase of 2nd order non-linear distortion on a ring radiator as well known "fact": Again, I know of nothing to support this. And you have once again given nothing to support this. Now it may be a well know fact as far as the Vifa XT25 is concerned, but your statement is "all inclusive" and the Vifa is NOT the Scan Speak.
4. As for other heard designs: What were the crossover freq.s and slopes? What was the pairing mid/woof (and what was its distortion like)? Is what you disliked about the sound have ANYTHING to do with a higher level of 2nd order IM distortion?
5. Will your proposed 2nd order Bessel at 3k provide that much less IM distortion than a LR 24th at 1.5k? (and thats just looking at the tweeter - which as I've mentioned twice before is a serious error..)
As for kissing bottom's: grow up.. (and while you are at it learn how to write so that others might give credence to your "vaulted" opinions.)
Big thankyou to 5th, Scott, Hans & Illusionxx
As always knowledgable input is always appreciated.
I'd also like to point out why so much weight has been placed on the performance of the Scan Ring is because of the fact that the choice of mid/bass has been up in the air.
Anyway just to flip this thing on its head, I've decided to go for a 3-way active design, still with the 4th order linkwitz XO of course.
My definite choice for the mid-range is now the ATC SM75-150S 3" dome mid. Its reputation is good, has perfect sensitivity matching for the Scan Ring and the fact that its closed back means I have no rear wave to worry about in the treble/mid box. I guess I could even go for open baffle. But I hate the aesthetics and no rear wave from the mid or treble drivers would kind of make it a mute point. So I'll stick with my original plan of housing mid-high's in one enclosure and the bass in another.
Oh - I also plan on crossing the ATC and Scan at 3Khz.
Right things are starting to come together now. I'll get onto Wilmslow, return the 15W's and replace with the ATC's. Bloody hell though - this is getting expensive now. If I get things right now, hopefully it will cure my sickness for building speakers almost on a monthly basis.
One other question thats at the fore front of my mind ATM is the choice for the bass? Looking for something that neutral, highly articulate with excellent resolution and good sensitivity. I do understand that sensitivity matching is trivial to fix with an active XO but I really want these to be dynamic and engaging speakers hence my preference for an efficient bass unit.
Thanks again all!
As always knowledgable input is always appreciated.
I'd also like to point out why so much weight has been placed on the performance of the Scan Ring is because of the fact that the choice of mid/bass has been up in the air.
Anyway just to flip this thing on its head, I've decided to go for a 3-way active design, still with the 4th order linkwitz XO of course.
My definite choice for the mid-range is now the ATC SM75-150S 3" dome mid. Its reputation is good, has perfect sensitivity matching for the Scan Ring and the fact that its closed back means I have no rear wave to worry about in the treble/mid box. I guess I could even go for open baffle. But I hate the aesthetics and no rear wave from the mid or treble drivers would kind of make it a mute point. So I'll stick with my original plan of housing mid-high's in one enclosure and the bass in another.
Oh - I also plan on crossing the ATC and Scan at 3Khz.
Right things are starting to come together now. I'll get onto Wilmslow, return the 15W's and replace with the ATC's. Bloody hell though - this is getting expensive now. If I get things right now, hopefully it will cure my sickness for building speakers almost on a monthly basis.
One other question thats at the fore front of my mind ATM is the choice for the bass? Looking for something that neutral, highly articulate with excellent resolution and good sensitivity. I do understand that sensitivity matching is trivial to fix with an active XO but I really want these to be dynamic and engaging speakers hence my preference for an efficient bass unit.
Thanks again all!
ShinOBIWAN said:
Yup, it's best to try for yourself and decide..
As far as excursion is concerned it shouldn't be a problem with a LR 4th order unless you play very high spl's. Remember IF the driver was flat on-axis from 1.5kHz down to 750 Hz (which it isn't) then the response would still be down a theoretical 24db's (more like 25 db's). Then factor in the drop from the driver itself.. Also consider that a manufacturer like Medolark uses them with a 1st order crossover - that even IF it was at 6kHz would only be down about 18db's at 750Hz (again if the driver's response was flat to this freq.). Also note that a 2nd order crossover at 3kHz would cause this driver more excursion than a 4th order at 1.5kHz.
As for a mid driver, IF you go the 4th order 1.5kHz route then the midbass you provided should be fine (but you'll still have baffle-step issues). If you decide to use a "real" midrange with the Scan Speak then I think you can't go wrong with the ATC (other than impeadance mismatch it sounds like a superb pairing). For a bass driver I'd consider the Beyma LX60 in a T-line (though with baffle-step loss you'll still be short some db's). (prob. side-mount the beyma..) If you decide to ditch the tweeter for another with more off-axis response then consider the LCY 130 and perhaps the Veravox 5X (which has a mms complementary with the ribbon - and a superb decay up to 7kHz). Same Beyma driver for bass (which notably is being used in the Overkill Audio Encore).
The VR-11 uses a proprietary audax aerogel mix that uses kevlar and carbon fiber in an acrlyic medium suspended with ceramic. The ceramic suspension was never offered to DIY'ers.
ShinOBIWAN said:Big thankyou to 5th, Scott, Hans & Illusionxx
As always knowledgable input is always appreciated.
I'd also like to point out why so much weight has been placed on the performance of the Scan Ring is because of the fact that the choice of mid/bass has been up in the air.
Anyway just to flip this thing on its head, I've decided to go for a 3-way active design, still with the 4th order linkwitz XO of course.
My definite choice for the mid-range is now the ATC SM75-150S 3" dome mid. Its reputation is good, has perfect sensitivity matching for the Scan Ring and the fact that its closed back means I have no rear wave to worry about in the treble/mid box. I guess I could even go for open baffle. But I hate the aesthetics and no rear wave from the mid or treble drivers would kind of make it a mute point. So I'll stick with my original plan of housing mid-high's in one enclosure and the bass in another.
Oh - I also plan on crossing the ATC and Scan at 3Khz.
Right things are starting to come together now. I'll get onto Wilmslow, return the 15W's and replace with the ATC's. Bloody hell though - this is getting expensive now. If I get things right now, hopefully it will cure my sickness for building speakers almost on a monthly basis.
One other question thats at the fore front of my mind ATM is the choice for the bass? Looking for something that neutral, highly articulate with excellent resolution and good sensitivity. I do understand that sensitivity matching is trivial to fix with an active XO but I really want these to be dynamic and engaging speakers hence my preference for an efficient bass unit.
Thanks again all!
Sounds like a good plan, my vote on the bass driver is still the Beyma LX60..
http://profesional.beyma.com/ENGLISH/producto.php
It has fairly high BL and "balanced" mass that should have that "punch" or "slam" thing going on while still being "nimble" and detailed. Combine this with the superb distortion levels (other world-ly good below fs) and good freq. linearity above 100 Hz. In-room extension with a T-Line would be extraordinary in the types of homes most of you brits have.
Dispersion on the ATC should be excellent up to 3kHz, so no worries here with lower crossovers..
No it's not. You've only been imagining it is.ScottG said:
Well silly ol' me. Here I am thinking that firsthand experience is worth something compared to a spec sheet, but I should have realized that you are far better informed, which naturally gives you every right to blow your trumpet like you know it all.
Excuse me for not ending every sentence I wrote with the ever so popular 'your mileage may vary' or IMHO... Just as a side note, I have found on forums that the more often ppl use these terms, the more likely it is that they mean the opposite.
No no no... that's not your problem. Your real problem is the way you approach me: it sucks! With that kind of testosterone attitude ppl are not likely to provide you with what you want, so excuse me for not digging in my archive instantly to find what you asked for.
I don't use the LDSG as a reference for driver with which I have firsthand experience. Unless you are uncertain of your findings, what would be the point in doing that? I stated the LDSG is a good reference, nothing else.
You might have assumed so, and frankly, I see no reason why you couldn't have. But that seems to be asking too much from you, doesn't it?
Well, now you do... that's how ppl learn stuff. Surrounds produce K2 distortion. A ringrad is a not much more than a surround. You figure out the rest.
AFAIK, the Vifa XT19/XT25 are a completely different driver. I wouldn't compare them with the SS ringrad. It would be similar to comparing a DX25 and a 9500. Look at Mark K's (Madisound) dist plots and you will see relatively high K2 compared to higher order dist and compared to conventional tweeters.
Click on this Ultimo link. There is a schematic in there somewhere.
It's not that easy to tell which slope is best. If you compare a LR2 at 3KHz with a LR4 at 1,5KHz you will see that the excursion at 750Hz is equal, but above 750Hz it is (much) lower for the LR2. At 1,5KHz the excursion of the LR4 is more than twice as high. Below 750Hz the LR4 has the advantage excursion wise. But at that frequency the LR2 is already 2 octaves from the xo point, at -24dB like the LR4. The distortion of the LR2 will be higher below 750Hz, but might be perceived as much smoother compared to the LR4 with its spike in the excursion at 1,5KHz. The Bessel will have even less excursion above 750Hz with possible benefit of having flat delay. You tell me what's best... I wouldn't know. It's entirely open for debate imo.
On the other hand, lower order xo's are easier to get 'right' whereas it is not trivial to get the your proposed LR4 electrical slope mentioned elsewhere in this thread to sound 'right', simply because higher order slopes are more vulnerable to measurement errors/component tolerances. A LR2 at 3KHz is quite easy to get 'just right' with a little bit of tweaking. That is not open for debate imo.
I have heard the SS7000 perform very well in two designs: (scroll down) Maxima and the big Magnat (which I remembered being a 3-way, but it's not... it's a 4-way so the tweeter will surely be crossed over higher than with a 2-way).
Apart form hearing the tweeter in a few designs, I have had the opportunity to attach the Ultimo to LspCad Pro's emulator, which gives a lot of information on the drivers in a very short time because you can try out and change the digital crossover on the fly. That experience alone gives much more info than any listening test or spec sheet will.
Suffice to say, I have the same source for the distortion plots as mentioned above. See Hobby Hifi 6/2002, but I think it was in Klang & Ton as well. I like the German magazines, but mainly for their driver reports. I find their recommendation of 1,5KHz rather silly. At 2,5KHz 90dB, the K2 distortion is already 1% and rising steadily. That is completely unacceptable in a high performance loudspeaker, assuming you would want high performance when you spend $500 per tweeter... The Neo8 in the same test (slightly cheaper...) performs much, much better at those frequencies (<2,5KHz). On the other hand, K3 and higher are exceptionally good (K3 0.01% and K5 way off the plot).
K2 may be less objectionable than higher order distortion are, but it still is... distortion.
What a pathetic way to end your post. But I have to give it to you: it is consistent in style and content. I don't think I need to learn how to write in English, but while reading your posts, it occurred to me that you're in more need of a spelling and grammar checker than I am (that’s "you're"... not "your" like your eloquent ego wrote in another post...).
Just a recap: you critisize me on my writing, but can't get your own language correctly on the screen... And you have problems with my well-founded opinion on the ringrad whereas you base your opinion on spec sheets...
Do you think there is something wrong with that? I mean, have you, your attitude and your spec sheets ever been near a Scan Speak ringrad? 
Without getting into the middle of this, I'll throw out my opinion, fwiw, since everyone is quoting my xt19/xt25 data.
I would like to, but have not tested one of these. I don't think you can assume identical performance, but similar performance is likely. The ringradiator concept has been around a long time. I think it was originally a jbl design, but it might have been around before jbl made a driver/series of drivers with it.
My guess is that it will have higher order 2nd order HD and IM. But, everything else will look very, very good. So you could probably do it, but you would have to accept higher second order distortion, which, all in all, is probably the least offensive. Because of it's remarkably low higher order products, complex tones would do fine, I think.
Still, at the price premium they are charging, I would expect better performance overall, compared with the 9x00 series. This seems to me a "niche" or "preference" tweeter, with higher directivity and lower higher order distortion at the expense of second order distortion products.
I would like to, but have not tested one of these. I don't think you can assume identical performance, but similar performance is likely. The ringradiator concept has been around a long time. I think it was originally a jbl design, but it might have been around before jbl made a driver/series of drivers with it.
My guess is that it will have higher order 2nd order HD and IM. But, everything else will look very, very good. So you could probably do it, but you would have to accept higher second order distortion, which, all in all, is probably the least offensive. Because of it's remarkably low higher order products, complex tones would do fine, I think.
Still, at the price premium they are charging, I would expect better performance overall, compared with the 9x00 series. This seems to me a "niche" or "preference" tweeter, with higher directivity and lower higher order distortion at the expense of second order distortion products.
Hans I've noticed that your in the Nederlands.
Would you happen to know of a company over there called BMM Electronics. I was hoping that you would have some experience with these or had any sort of opinion on their standing as a reputable company.
You see last week on the 25th Feb I ordered some DIY kits(active XO's, amps etc) for these very speakers that I'm working on now. I made payment via paypal and all transaction references in the paypal account screen show the payment as completed.
You would think that this is all well and good but and this is a BIG but... BMM are claiming that no such payment has been recieved according to their order tracking system. So I double checked my online banking and can confirm that the 650Euro's had been deducted from my bank account under the transaction heading of 'PAYPAL (BMM Elec.)'.
Well I thought I'd email them again and ask for more confirmation as to why the money had left my account was verified by paypal as completed yet they were saying otherwise. I took a few screen grabs of the original paypal 'payment successful' email that I recieved shortly after making the payment and also a few screen grabs of my paypal account status screen detailing the transaction and the fact that its been completed.
After 2 working days now I still have no word back from them and they still claim that payment hasn't been recieved at there end when checking with the automated order status page on their website. So I tried phoning them but all I get is a damned fax machine!
Now I'm left 650Euro's down with no visable means of contacting BMM, having tried several emails and telephone calls in vain - perhaps they are ignoring me, which would indicate that I'm being ripped off.
My next line of enquiry will be with paypal as I have tried to contact the merchant to no avail.
Any advice others could offer or people with direct experience dealing with BMM Electronics, could you please post here.
Many Thanks!
Would you happen to know of a company over there called BMM Electronics. I was hoping that you would have some experience with these or had any sort of opinion on their standing as a reputable company.
You see last week on the 25th Feb I ordered some DIY kits(active XO's, amps etc) for these very speakers that I'm working on now. I made payment via paypal and all transaction references in the paypal account screen show the payment as completed.
You would think that this is all well and good but and this is a BIG but... BMM are claiming that no such payment has been recieved according to their order tracking system. So I double checked my online banking and can confirm that the 650Euro's had been deducted from my bank account under the transaction heading of 'PAYPAL (BMM Elec.)'.
Well I thought I'd email them again and ask for more confirmation as to why the money had left my account was verified by paypal as completed yet they were saying otherwise. I took a few screen grabs of the original paypal 'payment successful' email that I recieved shortly after making the payment and also a few screen grabs of my paypal account status screen detailing the transaction and the fact that its been completed.
After 2 working days now I still have no word back from them and they still claim that payment hasn't been recieved at there end when checking with the automated order status page on their website. So I tried phoning them but all I get is a damned fax machine!
Now I'm left 650Euro's down with no visable means of contacting BMM, having tried several emails and telephone calls in vain - perhaps they are ignoring me, which would indicate that I'm being ripped off.
My next line of enquiry will be with paypal as I have tried to contact the merchant to no avail.
Any advice others could offer or people with direct experience dealing with BMM Electronics, could you please post here.
Many Thanks!
Hans L said:
Yes and no - spelling and grammar are not neccesarily needed for communication, though I will admit that "vaunted" and "vaulted" are not the same and could cause confusion.. As to contractions, well you seemed to understand what I meant rather well..
As I've said to others before in such enviorments, communication is the essential goal of an informal forum and it must be balanced against the writer and reader's time. Sure I could spell check, dictionary check, grammer check everything I have written - but it isn't worth my time and it isn't essential to communicate. Moreover, its "requirement" can be detrimental to others who do not have a full grasp of the language being used. (..and yes I am impressed with your language ability in english, but not your communication skills.) In a prof. enviorment of course things are quite different - and I write for a living (so yes I do have the tools and the skills, I just don't use them here).
................................
"First hand experience" is good, and I never said anything to the contrary. But you did not give your reader enough information other than to say "I do" ("or do not") like something. Even this would be perfectly acceptable (without a qualifier like IMO), however your "strong" opinion is so strong that it appears as a statment of fact. It is the appearance of fact supported by nothing more than opinion that is highly annoying, and could in fact be detrimental to someone who relies on it (principally ShinOBIWAN).
.................................
As to my approach:
1. I'm not the one who trashed my opinion.. (go back and read your first post in conjunction with my own). And no, I don't have a problem with being wrong if that is in FACT the case.
2. I'm not the one who used vulgarities to someone I don't even know..
..................................
Why would I assume you have knowledge of the driver's distortion? Furthermore why would I rely on this? - I don't know you. (And thank you for finally providing some tangible info on the driver's distortion.)
...................................
As to higher IM distortion of Ring Radiatiors in general - NO, I still don't have any information that supports this other than the d-s-t ring products (which may not have anything to do with general design). Your statement that it is fact means nothing without support (and support for such a broad statment should have broad support)..
....................................
Now THIS is a usefull reply (thank you):
"It's not that easy to tell which slope is best. If you compare a LR2 at 3KHz with a LR4 at 1,5KHz you will see that the excursion at 750Hz is equal, but above 750Hz it is (much) lower for the LR2. At 1,5KHz the excursion of the LR4 is more than twice as high. Below 750Hz the LR4 has the advantage excursion wise. But at that frequency the LR2 is already 2 octaves from the xo point, at -24dB like the LR4. The distortion of the LR2 will be higher below 750Hz, but might be perceived as much smoother compared to the LR4 with its spike in the excursion at 1,5KHz. The Bessel will have even less excursion above 750Hz with possible benefit of having flat delay. You tell me what's best... I wouldn't know. It's entirely open for debate imo.
On the other hand, lower order xo's are easier to get 'right' whereas it is not trivial to get the your proposed LR4 electrical slope mentioned elsewhere in this thread to sound 'right', simply because higher order slopes are more vulnerable to measurement errors/component tolerances. A LR2 at 3KHz is quite easy to get 'just right' with a little bit of tweaking. That is not open for debate imo.
I have heard the SS7000 perform very well in two designs: (scroll down) Maxima and the big Magnat (which I remembered being a 3-way, but it's not... it's a 4-way so the tweeter will surely be crossed over higher than with a 2-way).
Apart form hearing the tweeter in a few designs, I have had the opportunity to attach the Ultimo to LspCad Pro's emulator, which gives a lot of information on the drivers in a very short time because you can try out and change the digital crossover on the fly. That experience alone gives much more info than any listening test or spec sheet will.
Suffice to say, I have the same source for the distortion plots as mentioned above. See Hobby Hifi 6/2002, but I think it was in Klang & Ton as well. I like the German magazines, but mainly for their driver reports. I find their recommendation of 1,5KHz rather silly. At 2,5KHz 90dB, the K2 distortion is already 1% and rising steadily. That is completely unacceptable in a high performance loudspeaker, assuming you would want high performance when you spend $500 per tweeter... The Neo8 in the same test (slightly cheaper...) performs much, much better at those frequencies (<2,5KHz). On the other hand, K3 and higher are exceptionally good (K3 0.01% and K5 way off the plot).
K2 may be less objectionable than higher order distortion are, but it still is... distortion."
......................................
I'm still not sure the above validly supports the notion that a crossover at 2kHz or less is "worthless", but at least it provides some tangible basis for your conclusion..
In any event I've wasted more than enough time on this.. but if something like this should occur again then I will be able to provide a link (so the time spent here isn't a total waste..)
ShinOBIWAN said:
Just as a general note:
If you don't get satisfaction from BMM, nor from Paypal..
If you used a credit card (or if you used a protected debit account/card) to fund your paypal account then you might be able to have the transaction essentially "voided" with a small penalty. For inatance it is fairly common here in the states to have a $50 penalty voiding ability per transaction. It sounds like an account withdrawl for you - so you would have to check with your bank to see if they provide this service (and it may even be required by law in your jurisdiction).
Also, although it prob. isn't a problem you have, sometimes the checkout webpage is a highjacked bogus page (i.e. fraud). FireFox browser has a nice little plug-in that will verify what website you are actually on.
(just something to think about..)
Hi ShinOBIWAN,ShinOBIWAN said:
Sorry to hear this, I know how it feels when things appear to go wrong abroad. I buy lots of stuff over the internet, but it always ends well.
I've heard of the company and searched their website in the past. I've also heard of a few ppl who bought there without problems. So far it looks like an honest company to me. First thought on my mind: their bank may be slow, that happens with international transfers. Their telephone number is +31-(0)181-325835. You can call them yourself, but maybe I could help out if necessary. Not that I know anybody with a funny accent named Vince... capice?
But, if needed, I can persuade them to put in more effort. Let me know via mail if I can help.
Hans L said:
Hi ShinOBIWAN,
Sorry to hear this, I know how it feels when things appear to go wrong abroad. I buy lots of stuff over the internet, but it always ends well.
I've heard of the company and searched their website in the past. I've also heard of a few ppl who bought there without problems. So far it looks like an honest company to me. First thought on my mind: their bank may be slow, that happens with international transfers. Their telephone number is +31-(0)181-325835. You can call them yourself, but maybe I could help out if necessary. Not that I know anybody with a funny accent named Vince... capice?
Hans that a very gracious offer to act on my behalf and for that I thankyou.
As luck would have it the situation has changed since I wrote that post. BMM have now agreed that payment has reached them and said that goods will be dispatched in a timely manner when the boards have been assembled.
Should I have any problems in the future I'll email you and hopefully you could act as a dutch speaking intermediary. That would help things move along a lot smoother.
This might not be the correct place to ask since its really more of an amp question hence should be in among the amplifier threads but I'm a little confused as to how the whole kit that I've bought will work together, it has been recommend as a compatible package but BMM have as yet, provided no details on connection topology.
I'll post the question in a new post below this one and include some pictures of the parts for reference.
I've bought the following bits in kit form for assembly at home, these were all recommended as a compatible kit ie. it all works together.
The link to the amp is HERE
It uses Sanken SA1294 with SC3263 and is rated at around 2 x 140w into 8ohm
And here's a picture of the finished article.
For the power supply I went with this one HERE. Which is decribed as power supply for amplifiers - 2x56Vmax at 14A and 2x30V 200mA
Picture of completed PCB:
And the Input/Output stage is this one HERE
Picture of completed PCB:
Right my questions are twofold.
Firstly I would like to hear people opinions of the above and even better would be people with first hand experience. I have been told by a friend that it should be competent but will not offer a great performance.
You can also probably tell that this is my first step into DIY amplification but not electronics in general. I have about a year of basic theory behind me and a good soldering iron with the skill to use it well.
Secondly aside from people opinions on the performance I would like to know how the seperate components are likely to connect together. Luckily the pictures are rather large so identifying connectors shouldn't be a problem to someone familar with amp topology.
One thing that has me confused is the fact the amp looks to be dual voltage (2x56Vmax at 14A and 2x30V 200mA). I understand that you'd connect the 56V line to the amp but whats the 30V for?
Also confused as to why I'm going to need to use two toroidal's rated at 2x18v(8.3A 300VA) or at least thats what was recommended to me. Looking at the amp specs, it require 2x40-55V DC and these transformers don't seem to offer that sort of juice.
Cheers,
Ant
The link to the amp is HERE
It uses Sanken SA1294 with SC3263 and is rated at around 2 x 140w into 8ohm
And here's a picture of the finished article.
An externally hosted image should be here but it was not working when we last tested it.
For the power supply I went with this one HERE. Which is decribed as power supply for amplifiers - 2x56Vmax at 14A and 2x30V 200mA
Picture of completed PCB:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
And the Input/Output stage is this one HERE
Picture of completed PCB:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Right my questions are twofold.
Firstly I would like to hear people opinions of the above and even better would be people with first hand experience. I have been told by a friend that it should be competent but will not offer a great performance.
You can also probably tell that this is my first step into DIY amplification but not electronics in general. I have about a year of basic theory behind me and a good soldering iron with the skill to use it well.
Secondly aside from people opinions on the performance I would like to know how the seperate components are likely to connect together. Luckily the pictures are rather large so identifying connectors shouldn't be a problem to someone familar with amp topology.
One thing that has me confused is the fact the amp looks to be dual voltage (2x56Vmax at 14A and 2x30V 200mA). I understand that you'd connect the 56V line to the amp but whats the 30V for?
Also confused as to why I'm going to need to use two toroidal's rated at 2x18v(8.3A 300VA) or at least thats what was recommended to me. Looking at the amp specs, it require 2x40-55V DC and these transformers don't seem to offer that sort of juice.
Cheers,
Ant
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