Any 5" to 7" mid/midwoofers using an inverted surround?



I have had quite a few drivers with that same basket. Not any good for open baffle/dipole use. Yes in the beginning it sounds all good and well but in the end you'll always end up with the feeling something doesn't sound quite right. The difference in radiation patteren and frequency response is simply too big between front and back. there is no cure for it other than use it in a very narrow passband but that is not the intended purpose of the driver I guess.

Have a look at something like these

https://m.nl.aliexpress.com/item/32801336466.html?trace=wwwdetail2mobilesitedetail

Yes, I know, Chinese Ali-Express. I have had my reservations as well for years but it is hard to find any suitable dipole drivers from the usual suspect European manufactureres. I don't know these in particular but I have had very nice results with similar looking drivers, that is with very open baskets, paper cones and no surrounds at all, just paper folds in the cone itself. Over the years I have tried and abandonded each and every drivers with vented magnet, with vented spiders, with big spiderswith narrow baskets for open baffle/dipole use. Some sounded very good, very detailed and dynamic but always restricted, always with listening fatigue. Something hard to put a finger on but it was all gone when I stopped using drivers that where designed to be used in cabinets.
 

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I have had quite a few drivers with that same basket. Not any good for open baffle/dipole use. Yes in the beginning it sounds all good and well but in the end you'll always end up with the feeling something doesn't sound quite right. The difference in radiation patteren and frequency response is simply too big between front and back. there is no cure for it other than use it in a very narrow passband but that is not the intended purpose of the driver I guess.

Have a look at something like these

https://m.nl.aliexpress.com/item/32801336466.html?trace=wwwdetail2mobilesitedetail

Yes, I know, Chinese Ali-Express. I have had my reservations as well for years but it is hard to find any suitable dipole drivers from the usual suspect European manufactureres. I don't know these in particular but I have had very nice results with similar looking drivers, that is with very open baskets, paper cones and no surrounds at all, just paper folds in the cone itself. Over the years I have tried and abandonded each and every drivers with vented magnet, with vented spiders, with big spiderswith narrow baskets for open baffle/dipole use. Some sounded very good, very detailed and dynamic but always restricted, always with listening fatigue. Something hard to put a finger on but it was all gone when I stopped using drivers that where designed to be used in cabinets.

I don't need to "get a feeling" about a driver and whether it will sound "right". I take many very careful measurements, and that tells me what I need to know, including what passband would be appropriate. A pair of the AC180s is already on its way from a local retailer and will probably arrive tomorrow. If it doesn't work out I can return them for a refund.

The problem with buying an unknown driver from AliExpress based on a picture is that I have very little information at my disposal. What's the voltage sensitivity? TS parameters? Reputation of the "brand". Then if you buy the driver you have to measure the distortion level to know if you even want to try and use it. Even with known drivers it is a bit of a crapshoot. So I am not generally inclined to buy random drivers like that one. What if I want to share my design with others? Will the same driver (or even the same seller or brand) be available in 6 months time?

Edit: actually, it looks like the driver is already NLA. Your link is dead - page not found.

Sjef: can you get SB Acoustics drivers in Europe? I have had good luck with many, when used appropriately.
 
I have measured and listened to so many drivers over the years that I can tell you almost exactly how they will sound just by looking at them. To me, narrow baskets are a no go and that is varifiable with measurments. Specially narrow basket drivers mounted in thick front baflles is a recipe for listening fatigue in the long run. your milage may vary offcoarse, just share my experience.
 
I have measured and listened to so many drivers over the years that I can tell you almost exactly how they will sound just by looking at them. To me, narrow baskets are a no go and that is varifiable with measurments. Specially narrow basket drivers mounted in thick front baflles is a recipe for listening fatigue in the long run. your milage may vary offcoarse, just share my experience.
 
What does work in the long run for you then?

Simon

Drivers with a smooth freq response from front AND back of the driver with no cone-breakup, preferably with as low as possible mechanical resistance (rms) and high acceleration factor. And for the system as a whole a constant directivity from 30Hz to at least 6-7kHz. These parameters are more important than anything else when it comes to lifelike sound without listening fatigue even when listening for long hours a day.
 
Drivers with a smooth freq response from front AND back of the driver with no cone-breakup, preferably with as low as possible mechanical resistance (rms) and high acceleration factor. And for the system as a whole a constant directivity from 30Hz to at least 6-7kHz. These parameters are more important than anything else when it comes to lifelike sound without listening fatigue even when listening for long hours a day.

+1 to that!