-40 isn't so hot, I think it's better to say that the HM130 manages around -45dB, which is a tad better. Usually I would look for -50 across the entire midrange from a good performer today, with the 3rd harmonic preferably a bit lower. Lots of drivers manage this and from a variety of budgets too. When performing the distortion sweeps it's very easy to hear how cleaner something like the W15CY001 from SEAS is over the HM130Z0.
Of course, this is only looking at one aspect of the drivers and when I measure them I tend to do it at a fixed input level rather then a fixed SPL produced.
Here is a W15CY001
You will notice that it is a quite a bit cleaner, but as it is only 86dB sensitive the HM130Z0 will reach the same SPL with quite a bit less drive, so that would lower it's distortion somewhat and bring the two drivers a little closer together.
Of course the W15 costs quite a bit but you can get similar performance for a lot less, the Dayton RS series for example, the RS125...
These drivers typically fall away from the type of driver that the HM130Z0 is though. The HM has really been designed as a midrange driver, Audax therefore gave it a light cone and increased the drivers sensitivity as a result. This does result in a different kind of presentation to the typical 85-88dB mid/bass crowd and would be harder to reproduce with a driver of low overall sensitivity.
The only driver that I can think of that would be an appropriate candidate for a decent replacement for the HM130Z0, whilst hopefully maintaining some of its spec would be the 6ND430 from 18Sound. This is a 6.5" driver that has been optimised for mid/bass usage, but with more emphasis put on having higher sensitivity, it has similar parameters to the HM170Z0, but has class leading harmonic distortion.
For example though, here is a two way using an AP100Z0 and a cheap vifa tweeter @ 2.83v drive level. The crossover is steep around 2khz.
One thing that is immediately apparent is that the AP series motor isn't half bad at all and if Zaph's measurements of phase plugged/vs non phase plugged drivers is anything to go by, I bet getting some pole venting or rear basket venting as Jerome advised could well clean up the bass response a little too.
Now the AP series came quite a bit after the HM series I think, so they've got time on their side with regards to any improvements in motor design and I think it shows. The midrange distortion performance of the AP100Z0 is pretty much on a par with the HM130. Of course we cannot see what the AP does higher up as the tweeter takes over, but based on this limited set of data it would seem that going for the HM series might not be the best route to go down, if you're after a clear improvement, as the AP series is already pretty good to start with, and, imo, it certainly doesn't warrant the price premium that the HM series has over the AP.
Now the AP series is considerably different parameter-wise vs the HM series. The AP series is more like your typical hifi driver with low sensitivity designed for decent bass extension in small cabinets. If you want to escape that then you'd have to go for the HM series, but as said above the 18 sound driver probably represents a good modern day version of a HM driver, the only thing lacking is the Aerogel cone.
What you decide to do is ultimately up to you, I will make one thing clear however and that is that designing a new crossover for whatever choice you choose to make will be paramount to you actually realising any performance gains that any driver upgrade could be capable of providing.
Of course, this is only looking at one aspect of the drivers and when I measure them I tend to do it at a fixed input level rather then a fixed SPL produced.
Here is a W15CY001
You will notice that it is a quite a bit cleaner, but as it is only 86dB sensitive the HM130Z0 will reach the same SPL with quite a bit less drive, so that would lower it's distortion somewhat and bring the two drivers a little closer together.
Of course the W15 costs quite a bit but you can get similar performance for a lot less, the Dayton RS series for example, the RS125...
These drivers typically fall away from the type of driver that the HM130Z0 is though. The HM has really been designed as a midrange driver, Audax therefore gave it a light cone and increased the drivers sensitivity as a result. This does result in a different kind of presentation to the typical 85-88dB mid/bass crowd and would be harder to reproduce with a driver of low overall sensitivity.
The only driver that I can think of that would be an appropriate candidate for a decent replacement for the HM130Z0, whilst hopefully maintaining some of its spec would be the 6ND430 from 18Sound. This is a 6.5" driver that has been optimised for mid/bass usage, but with more emphasis put on having higher sensitivity, it has similar parameters to the HM170Z0, but has class leading harmonic distortion.
For example though, here is a two way using an AP100Z0 and a cheap vifa tweeter @ 2.83v drive level. The crossover is steep around 2khz.
One thing that is immediately apparent is that the AP series motor isn't half bad at all and if Zaph's measurements of phase plugged/vs non phase plugged drivers is anything to go by, I bet getting some pole venting or rear basket venting as Jerome advised could well clean up the bass response a little too.
Now the AP series came quite a bit after the HM series I think, so they've got time on their side with regards to any improvements in motor design and I think it shows. The midrange distortion performance of the AP100Z0 is pretty much on a par with the HM130. Of course we cannot see what the AP does higher up as the tweeter takes over, but based on this limited set of data it would seem that going for the HM series might not be the best route to go down, if you're after a clear improvement, as the AP series is already pretty good to start with, and, imo, it certainly doesn't warrant the price premium that the HM series has over the AP.
Now the AP series is considerably different parameter-wise vs the HM series. The AP series is more like your typical hifi driver with low sensitivity designed for decent bass extension in small cabinets. If you want to escape that then you'd have to go for the HM series, but as said above the 18 sound driver probably represents a good modern day version of a HM driver, the only thing lacking is the Aerogel cone.
What you decide to do is ultimately up to you, I will make one thing clear however and that is that designing a new crossover for whatever choice you choose to make will be paramount to you actually realising any performance gains that any driver upgrade could be capable of providing.
Attachments
Hey,
" comparable to the seas? "
Much higher Qms so much lower Rms than Seas.
" Scanspeak? Slightly cheaper?"
Mostly much cheaper but imo of nearly equal quality.
Nomes allergies? As I mentioned - available in paper as well:WF152BD03_04
Hoby-Hifi measured K2 around 0,3% and K3 at 0,1% @ 90dB/1kHz . What are excellent numbers.
G F
" comparable to the seas? "
Much higher Qms so much lower Rms than Seas.
" Scanspeak? Slightly cheaper?"
Mostly much cheaper but imo of nearly equal quality.
Nomes allergies? As I mentioned - available in paper as well:WF152BD03_04
Hoby-Hifi measured K2 around 0,3% and K3 at 0,1% @ 90dB/1kHz . What are excellent numbers.
G F
What numbers is concerned I like this 8" to thd -55 to -60DB and good linearity.
An externally hosted image should be here but it was not working when we last tested it.
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wow thanks everyone!
@Fabel, no i meant im more familiar with nomex when used as electrical insulation, and less familiar with it as a cone material.
Im assuming that the wavecore is comparable with the other nomex drivers ive seen. Seas? Better value also.
@ Fifth element, very interesting data...interesting that the AP100z0 is so close to the HM130. Funnily enough i have a pair of AP100 and AP130Z0...Confidence in the APs bolstered a bit by that, maybe the HMs arent a huge upgrade after all. Both the wavecore and seas look good. Also found an expensive davis audio 5" that looks good, however i doubt there are distortion plots easily available for them. I shall have a look and see what i can find.
@Fabel, no i meant im more familiar with nomex when used as electrical insulation, and less familiar with it as a cone material.
Im assuming that the wavecore is comparable with the other nomex drivers ive seen. Seas? Better value also.
@ Fifth element, very interesting data...interesting that the AP100z0 is so close to the HM130. Funnily enough i have a pair of AP100 and AP130Z0...Confidence in the APs bolstered a bit by that, maybe the HMs arent a huge upgrade after all. Both the wavecore and seas look good. Also found an expensive davis audio 5" that looks good, however i doubt there are distortion plots easily available for them. I shall have a look and see what i can find.
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This one is smaller a 6" like the post started. Only the rms na.
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.
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The actual measurement of the Davis isn't quite fair as the drivers tested were what one could call defective. One driver had the voice coil rubbing against the motor structure, so obviously wasn't used for testing. The other driver had it's suspension crushed so that the linear excursion, instead of reading +-4 mm, it read +1 -7 or something so was way off from being optimal. Still within the bounds of linear excursion it has decently low distortion. Overall the third harmonic is at or below -50dB, except for a small rise above 1khz which is par for the course in a lot of drivers. The second harmonic is also quite low except for the noted increase at low frequencies which Zaph attributed to the driver having only +1mm of linear excursion in one way.
I do feel that this is a bit unfair on Davis as the driver appears to be rather acceptable otherwise. Of course, it's expensive and you don't expect these kind of quality control issues on a driver costing north of $100. Davis might not be to blame for this however as a lot of drivers are packaged for delivery by the distributors and not the manufacturer. The manufacturer ships drivers in a complete palette of say 50 a time, then the distributor breaks them up into smaller quantities. Sometimes drivers come in their own manufacturer provided individual boxes, sometimes they don't, where the distributor has quite obviously packaged them for individual delivery.
Quality control and shipping issues aside, what does bother me is that Davis rate the driver as being 91dB and even though Zaph's measurement is an efficiency rather then a sensitivity, it still comes in far lower at ~83dB which is a world away from the 91dB.
Davis makes drivers with high quality material. They build the drivers in France, not in China, the price is obviously high.
I can talk about Davis speaker sound. I used the midbass 17KLV6a and the tweeter TW26T. The kevlar cone is very clean in the bass and mid but the upper mid and treble don't sound right, like the aerogel cone. The tweeter TW26T don't do high treble very well.
Nevertheless Davis have good drivers and speakers 😉
I changed my drivers by the Audax HM170Go and the SEAS 19TFF, the sound was more homogeneous, better to my ear.
I can talk about Davis speaker sound. I used the midbass 17KLV6a and the tweeter TW26T. The kevlar cone is very clean in the bass and mid but the upper mid and treble don't sound right, like the aerogel cone. The tweeter TW26T don't do high treble very well.
Nevertheless Davis have good drivers and speakers 😉
I changed my drivers by the Audax HM170Go and the SEAS 19TFF, the sound was more homogeneous, better to my ear.
From your point of view (briefly) how the TD6M from AE compare with 18Sound, others (B&C 6MD38, 6NDL38)?
Acoustic Elegance • View topic - TD6M - the Lambda Series Little Brother
http://www.bcspeakers.com/product.php?id=56
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It's difficult to say. The TD6 on paper looks very nice, although I have seen measurements of it where the user had a lot of trouble with a sizeable dip at around 800hz. It's covered in this thread over on HTguide and if not for that dip all the measurements lean quite heavily in its favour.
The B&C driver also looks fairly decent although it does have some sizeable bumps in the impedance plot that could indicate trouble zones. A lot of scan speak drivers show this too mind you, so they could be quite benign. One thing I've noticed with the pro drivers is that they aren't all good. I don't have any direct experience with them, but from the measurements I've looked at some either appear to be rather exceptional, such as the 18sound, whereas others tend to be rather more mediocre.
It seems that a few T/S parameters are being quoted as being beneficial towards end midrange sound quality too. I think it perhaps bares mentioning that any effects these may have should be present in the frequency/impedance and distortion plots. Typically a midrange driver will not be used close to resonance either which is where a large number of the T/S parameters are defined.
I think part of the attraction to the Aerogel HM series is their overall highish sensitivity. I remember when I first changed from the W15CY001 to the HM130Z0 the change was quite dramatic indeed with the sound seeming to leap out from the loudspeakers. Using higher sensitivity drivers has long been known to provide a more dynamic and exciting experience and I was quite taken in with the way the HM sounded. As time went on however you start to notice cracks in the armour, the HM, as has been said before is more coloured then the W15, not in a bad way but it wasn't entirely neutral. The W15 also sounded cleaner and I ended up swapping back to it. I am now using the FST midrange driver as used in B&Ws 800 series and this combines the best of both worlds, class leading harmonic distortion with very high sensitivity - it sounds like you'd expect it to, very very clean with almost effortless dynamics.
I think there's a lot to be said for higher sensitivity systems and if you can live with the limited bass extension, or you have subs, then I'd say it'd probably be very worthwhile trying out a higher sensitivity design.
At some point I'll probably get around to trying a small 2 way with the HM130Z0, just to see what it's like run full range. As I've mentioned before though getting the crossover right is the most important thing with a multi-way design. Some drivers need a perfectly executed xover to sound decent, whereas others are far more forgiving. Don't forget about this as you could find yourself disliking a driver simply because your implementation isn't perfect.
Mondogenerator, where about in the UK do you live?
@ Michael: Ive quickly looked at the HM130C0, and it doesnt look too bad at all. I would assume by what Fifth element and others have said that the 'C0' is in the same ballpark as the 'Z0' for distortion figures, and therefore may not be a large improvement over the AP130Z0 i have currently.
The AP series doesnt really have alot I can criticise, except lack of motor venting(if thats really a bad thing as such), but the rolloff is relatively easy to deal with. Im not sure the 'C0' would be as simple to crossover.
The AP series doesnt really have alot I can criticise, except lack of motor venting(if thats really a bad thing as such), but the rolloff is relatively easy to deal with. Im not sure the 'C0' would be as simple to crossover.
@Fifth element:
Im in the midlands...Coventry...cesspit of the midlands lol
I think the HM aerogels are probably out of the question. not enough performance gain:cost ratio lol. I just feel that HDA had a good balance of flex and rigidity, better than many paper cones.
Ive also got visaton AL130, which are rigid coned, and these sound good, once the breakup peak is attenuated, but i dont like that to get it flat(within 2dB) I end up with a 83dB/W speaker....The worst thing is that im not strictly a fan of high efficiency drivers, BUT 87-90dB is a nice place to aim. These probably have very good distortion figures, so maybe I like the sound of distortion....🙁
The davis drivers attracted me because of the extended high mid response, and benign rolloff. Ts are similar to the AP130Z0, so cabinet mods would be minimal, crossover would obviously need a total redesign. The price is the issue.
maybe its a trick of my mind, but until I hear one, I couldnt say that Nomex was any better than paper, and despite paper being the most versatile and variable medium for cones, any that i have tried SO FAR, seem a backward step from the AP's
Im in the midlands...Coventry...cesspit of the midlands lol
I think the HM aerogels are probably out of the question. not enough performance gain:cost ratio lol. I just feel that HDA had a good balance of flex and rigidity, better than many paper cones.
Ive also got visaton AL130, which are rigid coned, and these sound good, once the breakup peak is attenuated, but i dont like that to get it flat(within 2dB) I end up with a 83dB/W speaker....The worst thing is that im not strictly a fan of high efficiency drivers, BUT 87-90dB is a nice place to aim. These probably have very good distortion figures, so maybe I like the sound of distortion....🙁
The davis drivers attracted me because of the extended high mid response, and benign rolloff. Ts are similar to the AP130Z0, so cabinet mods would be minimal, crossover would obviously need a total redesign. The price is the issue.
maybe its a trick of my mind, but until I hear one, I couldnt say that Nomex was any better than paper, and despite paper being the most versatile and variable medium for cones, any that i have tried SO FAR, seem a backward step from the AP's
As far as I am aware all of the Audax drivers in the HM series use similar motors. Different cones have different properties and generally the main differences will be in how the cone goes through break up. You may think that the cone material could be looked at as being a separate entity, that is in comparison to the motor and suspension elements. The trouble with this is that certain cone materials will act to amplify the non linearities that an otherwise decently linear motor will present.
For example you could have a motor that would present a driver with harmonics at around -45dB. This in itself is nothing amazing, but decent at a low price point. If you were to couple with it a well designed, inherently self damped low resonance cone, you could end up with a great budget driver. If however you attached a stiffer cone that as a result had some rather nasty (but not metal cone nasty) breakup it could impact the HD plot and cause elements within it to push up into the <-40dB region and you'd be less inclined to use this driver.
There might actually be nothing wrong with the cone, it may show purely pistonic behaviour up to a useful frequency such as 1.5khz, but when placed on the mediocre motor it makes for a troublesome driver. Place the cone onto something a little better and the average distortion drops by 10dB and the peaks associated with the cone breakup are also a further 10dB down and now are less of a concern and you've got a nice driver once again.
Audax liked to experiment with different cone materials, often offering several versions of one driver, one with a pure paper cone, one a doped paper cone, then a carbon fibre, aerogel and sometimes a glass fibre or plastic cone too. The Aerogel cones do display some quite nasty resonances and in the measurements of the HM130Z0 that I posted I had stuck some strips of foam to the cone, these smoothed out the breakup region somewhat and resulted in a slightly cleaner looking HD plot too.
Audax liked to apply quite a lot of smoothing to the upper response curves of their older reference series such that the breakup was made less severe. You can see in the G14 and the Z10 of the later models that they adopted a more honest approach with the breakup displayed in all its peaky glory, so who knows what the full story with the carbon fibre cone would be? Sometimes cone resonances don't turn up as extra distortion products and sometimes they do.
AUDAX, LA PASSION DU HAUT-PARLEUR has all of the relevant data sheets.
It's a shame that Audax stopped developing their publicly available consumer line as I am sure they would have produced some quite interesting products as a result. Nowadays though and entirely based on my own opinion, you're better off spending your money elsewhere.
For example you could have a motor that would present a driver with harmonics at around -45dB. This in itself is nothing amazing, but decent at a low price point. If you were to couple with it a well designed, inherently self damped low resonance cone, you could end up with a great budget driver. If however you attached a stiffer cone that as a result had some rather nasty (but not metal cone nasty) breakup it could impact the HD plot and cause elements within it to push up into the <-40dB region and you'd be less inclined to use this driver.
There might actually be nothing wrong with the cone, it may show purely pistonic behaviour up to a useful frequency such as 1.5khz, but when placed on the mediocre motor it makes for a troublesome driver. Place the cone onto something a little better and the average distortion drops by 10dB and the peaks associated with the cone breakup are also a further 10dB down and now are less of a concern and you've got a nice driver once again.
Audax liked to experiment with different cone materials, often offering several versions of one driver, one with a pure paper cone, one a doped paper cone, then a carbon fibre, aerogel and sometimes a glass fibre or plastic cone too. The Aerogel cones do display some quite nasty resonances and in the measurements of the HM130Z0 that I posted I had stuck some strips of foam to the cone, these smoothed out the breakup region somewhat and resulted in a slightly cleaner looking HD plot too.
Audax liked to apply quite a lot of smoothing to the upper response curves of their older reference series such that the breakup was made less severe. You can see in the G14 and the Z10 of the later models that they adopted a more honest approach with the breakup displayed in all its peaky glory, so who knows what the full story with the carbon fibre cone would be? Sometimes cone resonances don't turn up as extra distortion products and sometimes they do.
AUDAX, LA PASSION DU HAUT-PARLEUR has all of the relevant data sheets.
It's a shame that Audax stopped developing their publicly available consumer line as I am sure they would have produced some quite interesting products as a result. Nowadays though and entirely based on my own opinion, you're better off spending your money elsewhere.
If you were in Manchester I was going to give you the offer of some assistance with measuring/designing the things if it were needed. No one is ever in Manchester though!
This is the way that I feel too, although not bad drivers, the gains are too small to be worth the extra price, especially considering the current competition.
There are a variety of composite materials from a few names that attempt to do a similar kind of thing. One is Eton with their Hexacone, the trouble with the Etons is their motors aren't all that great either. Then you've got Aurum Cantus who like to use materials made of an unwoven cabon fibre and kevlar mix, similar in a way to Aerogel. Their AC130/50CK has an excellent motor that gives a nice HD plot, the trouble here is with the cone offering a difficult breakup region, that although workable would be a bit of a pain.
http://www.zaphaudio.com/temp/AurumCantus-AC130-50CK-FR.gif
http://www.zaphaudio.com/temp/AurumCantus-AC130-50CK-HD.gif
If they were easier to get a hold of, at some point I'd probably be interested in trying them out.
Zaph had measured the AL200 and that had fairly impressive numbers, if the AL130 is anything like it then it'll be a good enough driver. That's half of the trouble with lower sensitivity drivers you end up with a loudspeaker in the lower end of the 80-85 region once you've taken bafflestep and other issues into consideration. Even with the higher sensitivity pro woofers like the 18Sound, you'd be at around 88dB after BSC.
Don't discount the system design and crossover implementation as being a dominating factor in all of this. A well implemented system should sound good regardless of the cone materials used. The AP130s are by no means anything exceptional and any of the good drivers that have been recommended in this thread should be able to out perform it. The AP130 isn't that sensitive either, for a finalised design both the AP and AL130 should end up with a similar system sensitivity. Maybe you should look into having another go with the AL130s.
hahaha Thats me whole problem. Too many projects going on at the same time. The visatons are as smooth as i can get them, although not as smooth as the LS3/5A, they are better in other ways. With a better xover the Audax are roughly a similar sensitivity, something on the Audax just seems more 'live'....
perhaps i should work on reducing the level of BSC on the visatons instead....
Haha no-one lives in Manchester......funny, half the people I grew up with 'ran away' to mancs, so obviously Coventry is repelling them.
perhaps i should work on reducing the level of BSC on the visatons instead....
Haha no-one lives in Manchester......funny, half the people I grew up with 'ran away' to mancs, so obviously Coventry is repelling them.
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