Re: Re: Measurement echnique for in Depth Investigation of Thermal Transient Response
I'm not sure why this needed to turn into a big mess. The point I made about the 3rd party testing is simply that I can spend all the time I want doing tests to prove my claims, but because I am the one doing the testing, i'm already biased and people will doubt the results. Funny thing with the JBL testing is that another company who's drivers are listed on there has a similar test published but the results show their drivers with less compression than the JBL. I'd rather not have any issues with people doubting the testing environment, etc and let someone 3rd party, unbiased, like Lynn do the testing. I believe should be fully qualified and impartial, do you agree?
I don't necessarily agree with the con of faster heat up, higher equilibrium resistance. At least not in the case of a woofer with full copper sleeve on the pole One of the biggest advantages to the Lambda phase plug design is that the copper sleeve will pull heat from the coil and do it much more quickly than a steel pole. Heat travels from the hotter medium to the cooler medium, coil to copper sleeve, to pole, to phase plug, and out to the air. A good amount of heat is expelled from the front of the phase plug. This helps to keep the air temperature inside the enclosure lower, which can contribute to the higher equilibrium resistance. Also, without the copper to pull heat from the coil, the coil itself will heat much quicker. The benefit of a dustcap/vented pole doesn't do much until the steel pole heats up enough that the air being forced through the pole vent helps to cool it.
We do use black anodized aluminum combined with kapton for the formers. The initial benefit to the alum former is that it pulls heat from the coil. I have kapton only versions of many of the VC's. I can easily build 2 identical drivers with the same coil wound on kapton and on the anodized alum former and show you the results of the 2 options on QMS.
I have personally compared them to many drivers in many different ways. Keep in mind, back about 8 yrs ago I wasn't associated with Lambda. I was basically a customer. I've compared them to many drivers, but which ones would you consider real? I've done head to head comparisons with 3" and 4" VC EV woofers, Altecs, TAD1601's, JBL's, etc. Keep in mind we have a tiny 2" diameter VC that has been on par with these much bigger 3" and 4" coil drivers in terms of compression.
Jeff Bagby comments from the HTGuide thread:
There are a lot of great woofers out there, some even play well into the midrange. We recently used a JBL 2206 for a similar speaker. The Lambda appears to significantly out-perform the more expensive JBL though. Aside from having a 22Hz Fs and 11mm of Xmax, it has full length Faraday sleeve that reduces Le to .30mH, which is about the level you find in a 4" driver. Consequently, one of the most significant sources of distortion (inductance) is reduced to a very low level. This driver has very low levels of distortion in the midrange for being able to produce good bass at the same time. I am not aware of another driver that approaches this.
It's interesting you claim that they haven't been compared to any "real" drivers. However, according to the JBL chart, the 2206H with vented gap technology is literally one of their best drivers. Again, we are not avoiding any kind of comparison. I simply don't want any questions about whether or not we doctored the results, had any kind of bias, etc.
John
mige0 said:
I'm not sure why this needed to turn into a big mess. The point I made about the 3rd party testing is simply that I can spend all the time I want doing tests to prove my claims, but because I am the one doing the testing, i'm already biased and people will doubt the results. Funny thing with the JBL testing is that another company who's drivers are listed on there has a similar test published but the results show their drivers with less compression than the JBL. I'd rather not have any issues with people doubting the testing environment, etc and let someone 3rd party, unbiased, like Lynn do the testing. I believe should be fully qualified and impartial, do you agree?
I don't necessarily agree with the con of faster heat up, higher equilibrium resistance. At least not in the case of a woofer with full copper sleeve on the pole One of the biggest advantages to the Lambda phase plug design is that the copper sleeve will pull heat from the coil and do it much more quickly than a steel pole. Heat travels from the hotter medium to the cooler medium, coil to copper sleeve, to pole, to phase plug, and out to the air. A good amount of heat is expelled from the front of the phase plug. This helps to keep the air temperature inside the enclosure lower, which can contribute to the higher equilibrium resistance. Also, without the copper to pull heat from the coil, the coil itself will heat much quicker. The benefit of a dustcap/vented pole doesn't do much until the steel pole heats up enough that the air being forced through the pole vent helps to cool it.
Charles, study the datasheets I presented for proof or find some others.
Before arguing with me - argue with the manufactures that in fact WERE able to implement metal VC formers well.
"Then, when you finally get it, I would recommend coming back here..."
We do use black anodized aluminum combined with kapton for the formers. The initial benefit to the alum former is that it pulls heat from the coil. I have kapton only versions of many of the VC's. I can easily build 2 identical drivers with the same coil wound on kapton and on the anodized alum former and show you the results of the 2 options on QMS.
I have personally compared them to many drivers in many different ways. Keep in mind, back about 8 yrs ago I wasn't associated with Lambda. I was basically a customer. I've compared them to many drivers, but which ones would you consider real? I've done head to head comparisons with 3" and 4" VC EV woofers, Altecs, TAD1601's, JBL's, etc. Keep in mind we have a tiny 2" diameter VC that has been on par with these much bigger 3" and 4" coil drivers in terms of compression.
Jeff Bagby comments from the HTGuide thread:
There are a lot of great woofers out there, some even play well into the midrange. We recently used a JBL 2206 for a similar speaker. The Lambda appears to significantly out-perform the more expensive JBL though. Aside from having a 22Hz Fs and 11mm of Xmax, it has full length Faraday sleeve that reduces Le to .30mH, which is about the level you find in a 4" driver. Consequently, one of the most significant sources of distortion (inductance) is reduced to a very low level. This driver has very low levels of distortion in the midrange for being able to produce good bass at the same time. I am not aware of another driver that approaches this.
It's interesting you claim that they haven't been compared to any "real" drivers. However, according to the JBL chart, the 2206H with vented gap technology is literally one of their best drivers. Again, we are not avoiding any kind of comparison. I simply don't want any questions about whether or not we doctored the results, had any kind of bias, etc.
John
Member
Joined 2004
Re: Re: Re: Re: Re: Good Articles
Rms = cone area related, so you cannot compare between different diameter drivers. The smaller driver will always have a lower Rms.
So the 0.49 kg/s you quote from the 7 icnh XT19W009-08 is in comparison lower than the 0.36 of the 4 inch.
Not to be smart, just to end this misinterpretation
Regards
Roland
mige0 said:
Rms = cone area related, so you cannot compare between different diameter drivers. The smaller driver will always have a lower Rms.
So the 0.49 kg/s you quote from the 7 icnh XT19W009-08 is in comparison lower than the 0.36 of the 4 inch.
Not to be smart, just to end this misinterpretation
Regards
Roland
augerpro said:
Yes, the throat has a perfect round entrance then goes to an elliptical shape then goes out to round again. They sound very good, better than the 18 Sound XT120 and far more open then my round tractrix horns. If you look at the Renkus Heinz site you'll see they also make some cool elliptical horns.
Re: Re: Re: Measurement echnique for in Depth Investigation of Thermal Transient Resp
I am not impressed with the 2226/2206 series JBLs. Look at the 2227 or 2242 for a 'real' driver from them.
I do not consider a magazine or a website that takes money for advertisements a source of real meaningful information.
John_E_Janowitz said:
I am not impressed with the 2226/2206 series JBLs. Look at the 2227 or 2242 for a 'real' driver from them.
I do not consider a magazine or a website that takes money for advertisements a source of real meaningful information.
Re: Re: Re: Re: Measurement echnique for in Depth Investigation of Thermal Transient
The quote was pulled from a forum thread just like this one, however the design Jeff was working on was a commercial design. Note though that I don't think Jeff would cave to marketing blather.. BUT I also don't think he has a wide degree of experience with more eff. drivers - so I don't think it adds much "weight" to the topic.
None of JBL's recent offerings are really "real" drivers. They are all caught up with thermal compression for long and loud pro use. Domestically we may achieve some pretty high spl peaks (program dependent), but on average most of us never exceed 100 db (and rarely 95 db), so such engineering is a waste.
I'm also not convinced of the recent "I need low inductance for low distortion" argument. Low inductance usually leads to low distortion at higher freq.s - a fairly moot point if you don't operate the driver near its upper freq. limit. IF however you are going wide-band, then yes, it *can* become more important - usually to a modest degree. Note though that some wide-band drivers RELY on it (to an extent) to lower their on-axis response (..which is usually elevated due to a very high strength motor).
I however *like* the idea behind 18 Sound's "active impedance".. but NOT because of its reduction in non-linear distortion. What I think is particularly worthwhile with such a design is that its significantly reducing the amount of "back"-current into the pairing amplifier. This is fairly meaningless for an amplifier with a high current power supply.. but with a typical low current (and low power) amplifier you *can* achieve ***much*** better sound. (..note though that their drivers still have an overly stiff surround - good for pressure operation but suboptimal for velocity operation).
Magnetar said:
The quote was pulled from a forum thread just like this one, however the design Jeff was working on was a commercial design. Note though that I don't think Jeff would cave to marketing blather.. BUT I also don't think he has a wide degree of experience with more eff. drivers - so I don't think it adds much "weight" to the topic.
None of JBL's recent offerings are really "real" drivers. They are all caught up with thermal compression for long and loud pro use. Domestically we may achieve some pretty high spl peaks (program dependent), but on average most of us never exceed 100 db (and rarely 95 db), so such engineering is a waste.
I'm also not convinced of the recent "I need low inductance for low distortion" argument. Low inductance usually leads to low distortion at higher freq.s - a fairly moot point if you don't operate the driver near its upper freq. limit. IF however you are going wide-band, then yes, it *can* become more important - usually to a modest degree. Note though that some wide-band drivers RELY on it (to an extent) to lower their on-axis response (..which is usually elevated due to a very high strength motor).
I however *like* the idea behind 18 Sound's "active impedance".. but NOT because of its reduction in non-linear distortion. What I think is particularly worthwhile with such a design is that its significantly reducing the amount of "back"-current into the pairing amplifier. This is fairly meaningless for an amplifier with a high current power supply.. but with a typical low current (and low power) amplifier you *can* achieve ***much*** better sound. (..note though that their drivers still have an overly stiff surround - good for pressure operation but suboptimal for velocity operation).
The 2242 is a real driver Scott - I have been using them for years the 2227 uses the same basic technology and I assume it's the same - the 2226, 2206, 2241 were all major disappointments to me - there is a lot of singers about those too
Low inductance and 2" coils - sounds like a tweeter to me
I'd like to try a pair of the 18 Sounds too! Those may be in the same league as 2242 - maybe better! And they look to be using that technology in a mid - that will be my next driver-- looks like I need to sell some stuff so I can have them
Low inductance and 2" coils - sounds like a tweeter to me
I'd like to try a pair of the 18 Sounds too! Those may be in the same league as 2242 - maybe better! And they look to be using that technology in a mid - that will be my next driver-- looks like I need to sell some stuff so I can have them
Magnetar said:
In the 15" category look to the old oem Ciare 15.64NdW1.. good qe and qm - AND with only a 2.5 inch coil.
Under normal operation this would put the 2227 to shame (sound-wise).. and you would feel down right abused at the price difference.
At one time Ciare had some drivers with qm's nearing 20 and fairly low qe's, unfortunately they have never had decent linear excursions (..to be expected though considering the more compliant suspension).
I'll give you the 2242 though, mostly because there isn't a lot better in 18" drivers.
Hi all, I've been busy the last few days. Here's an updated drawing that I'll be showing to the local Northern Colorado woodworkers - I'm still awaiting delivery of several key components, the AH-425, the 288-16H's, and the 414-16A's. The 12NDA520's, the 6ND410's, and the RAAL 140-15D are already on hand.
Thus far, I've spent about US$3000, and I expect to spend another US$1000~2000 before measurements and audition can start. So I'm definitely committed, although I have no idea if it will be completed in time for the RMAF show. Frankly, just moving them to and from the show is such a hassle that I don't feel much incentive to demo them at the show. The last time I took the Karna's to the show, it definitely wasn't worth the effort - the amps nearly got demolished by careless show-goers not looking where they were stepping, and the actual demo lasted maybe half-an-hour. It took longer to move them to and from the show than the time they were up and running.
Thus far, I've spent about US$3000, and I expect to spend another US$1000~2000 before measurements and audition can start. So I'm definitely committed, although I have no idea if it will be completed in time for the RMAF show. Frankly, just moving them to and from the show is such a hassle that I don't feel much incentive to demo them at the show. The last time I took the Karna's to the show, it definitely wasn't worth the effort - the amps nearly got demolished by careless show-goers not looking where they were stepping, and the actual demo lasted maybe half-an-hour. It took longer to move them to and from the show than the time they were up and running.
Attachments
Lynn Olson said:
An externally hosted image should be here but it was not working when we last tested it.
Hey Lynn, I hauled this to a show and although people said it sounded great I thought it sounded like crap. The walls were fake and rattled plus the windows reflected sound all around - taking a beast to a 'show' is something I'll never do This was a heavy system. The subs in the back used four 15's each.
Dipoles would be easy .......
Re: Measurement echnique for in Depth Investigation of Thermal Transient Response of
The only thing explosive has been the fact that you know very little about driver design but yet want to argue with me about things that are obvious to anyone that has glued a speaker together.
If you have noticed I only comment on things that I know about, there is plenty here that flies completely over my head. If you would do the same we wouldn't be this far off track.
I won't lose the third party power testing, sorry.
Another respected 3rd party test in the works.
Yes you can hear cymbal shots on them though not as good as a tweeter. It is a byproduct of the design that I will admit I was not working to achieve. However I cannot complain as it makes crossover implementation much easier.
People always comment on the 2" voice coil when in fact it probably has as much wire as a 4" JBL SVG since the winding length is so much longer. Then consider the only heat sink for the JBL voice coil is the steel pole and plate...........
mige0 said:
The only thing explosive has been the fact that you know very little about driver design but yet want to argue with me about things that are obvious to anyone that has glued a speaker together.
If you have noticed I only comment on things that I know about, there is plenty here that flies completely over my head. If you would do the same we wouldn't be this far off track.
I won't lose the third party power testing, sorry.
chrismercurio said:
Another respected 3rd party test in the works.
Magnetar said:
Yes you can hear cymbal shots on them though not as good as a tweeter. It is a byproduct of the design that I will admit I was not working to achieve. However I cannot complain as it makes crossover implementation much easier.
People always comment on the 2" voice coil when in fact it probably has as much wire as a 4" JBL SVG since the winding length is so much longer. Then consider the only heat sink for the JBL voice coil is the steel pole and plate...........
Re: Re: Measurement echnique for in Depth Investigation of Thermal Transient Response
Well, I can hear cymbal shots through just about any woofer - I have some 12's here (old alnico EV SRO/12') with 2.5" voice coil and it is the best midrange driver I have ever heard (this week) plus it's really efficient. I am comparing them to some super quad 57's as I type this
nickmckinney said:
Well, I can hear cymbal shots through just about any woofer - I have some 12's here (old alnico EV SRO/12') with 2.5" voice coil and it is the best midrange driver I have ever heard (this week) plus it's really efficient. I am comparing them to some super quad 57's as I type this
Re: Re: Re: Re: Re: Measurement echnique for in Depth Investigation of Thermal Transi
Scott,
Maybe is my ignorance, but is this an "academic" way of saying that the stiff surrounds are good for high SPLs (as being the pro speakers they are and their power ratings suggest) but less so for microdynamics and "delicacy" (in 'phile speak) ?
Scott,
ScottG said:
Maybe is my ignorance, but is this an "academic" way of saying that the stiff surrounds are good for high SPLs (as being the pro speakers they are and their power ratings suggest) but less so for microdynamics and "delicacy" (in 'phile speak) ?
speaker alignment
hello Linn
how about a driver alignment as on my drawing ? similar to Jack Bouskas speakers ?
the radiation pattern of the midrange horn is quite wide. The Raal is however more narrowed. So there is a missmatch between these, unless you will use foam.
The OB mid and bass drivers have also a completely different polar pattern and radiation behaviour, than the midrange horn, and Raal tweeters, radiating also backwards. So actually , nothing will match. Specially at the crossover points.
i am wrong about that ?
A direct radiating woofer, close to the floor is very clear audible, where the source is located. Similar to your design. With a row, from the ceiling to the floor, however, the radiation would be much more even , what in my opinion would be preferable.
Angelo
__________________________________
http://www.flickr.com/photos/12312992@N07/page1/
http://www.audiovoice-acoustics.com/forum/
hello Linn
how about a driver alignment as on my drawing ? similar to Jack Bouskas speakers ?
the radiation pattern of the midrange horn is quite wide. The Raal is however more narrowed. So there is a missmatch between these, unless you will use foam.
The OB mid and bass drivers have also a completely different polar pattern and radiation behaviour, than the midrange horn, and Raal tweeters, radiating also backwards. So actually , nothing will match. Specially at the crossover points.
i am wrong about that ?
A direct radiating woofer, close to the floor is very clear audible, where the source is located. Similar to your design. With a row, from the ceiling to the floor, however, the radiation would be much more even , what in my opinion would be preferable.
Angelo
An externally hosted image should be here but it was not working when we last tested it.
__________________________________
http://www.flickr.com/photos/12312992@N07/page1/
http://www.audiovoice-acoustics.com/forum/