I am looking at purchasing 2 of these drivers but am confused.
On the Peerless Tymphany website the FS is given as 78hz and vas 2.38 l.
But when I go to a website to look at the drivers the figures are all different and yet the model no is the same. I have seen the FS given as 156hz and vas as 0.7 l.
Any thoughts
On the Peerless Tymphany website the FS is given as 78hz and vas 2.38 l.
But when I go to a website to look at the drivers the figures are all different and yet the model no is the same. I have seen the FS given as 156hz and vas as 0.7 l.
Any thoughts
So it would not matter where I purchase from even if its someone who says the fs is 156hz.
So there is only one model but different specs and spec sheets.
I have even seen a Peerless spec sheet with 156hz and different qts etc.
Still not sure what volume to use though.
Colmo, most of the time when you are figuring out what size box to put a driver into, it's all about getting the LF response that you think will be optimal. But with a mid in a 3-way, you are going to roll the low end off to blend with your woofer usually well before the F3 point so getting the 'best' LF response out of the mid isn't really that significant any more.
Instead you might give more consideration to things like rear wave reflections and absorption, the box compliance ratio and perhaps the mid cabinet resonances when you are determining the mid chamber size. Overall speaker size and aesthetics might factor as well.
So in this regard, I have seen small mid chamber, large chamber and aperiodic chamber approaches. Personally I have had success with the larger mid chamber approach. I want to make the chamber large enough so that I leave a fair amount of empty room behind the driver for it to breath and then still enough room to add in several different layers of sound absorption material to absorb as much of the rear energy as possible. Perhaps also enough room for bracing and extrusional damping on the walls with something like bitumen pads. And I have a preference for a tapering rear chamber like an inverted cone because that shape helps with the rear energy absorption as well.
The larger chamber also means that the compliance ratio will be large or in other words, the driver suspension will be the primary restorative force and not the air pressure within the box. So the driver will be 'looser' which should give you a little bit more low level detail than if it were stiffer from higher air pressure. Air pressure in the box stops being the primary restorative force when the box volume exceeds the driver's Vas, in this case 2.13L so that would be the absolute minimum net volume I would go for.
Now using the version 2 data for that driver, suggested sealed box volume with Qtc at .7 is about 1L but that's too small for me. Suggested volume with a Qtc of .5 is about 3L so I would probably go with somewhere between 3L to 5L depending on what works for you in your design.
Instead you might give more consideration to things like rear wave reflections and absorption, the box compliance ratio and perhaps the mid cabinet resonances when you are determining the mid chamber size. Overall speaker size and aesthetics might factor as well.
So in this regard, I have seen small mid chamber, large chamber and aperiodic chamber approaches. Personally I have had success with the larger mid chamber approach. I want to make the chamber large enough so that I leave a fair amount of empty room behind the driver for it to breath and then still enough room to add in several different layers of sound absorption material to absorb as much of the rear energy as possible. Perhaps also enough room for bracing and extrusional damping on the walls with something like bitumen pads. And I have a preference for a tapering rear chamber like an inverted cone because that shape helps with the rear energy absorption as well.
The larger chamber also means that the compliance ratio will be large or in other words, the driver suspension will be the primary restorative force and not the air pressure within the box. So the driver will be 'looser' which should give you a little bit more low level detail than if it were stiffer from higher air pressure. Air pressure in the box stops being the primary restorative force when the box volume exceeds the driver's Vas, in this case 2.13L so that would be the absolute minimum net volume I would go for.
Now using the version 2 data for that driver, suggested sealed box volume with Qtc at .7 is about 1L but that's too small for me. Suggested volume with a Qtc of .5 is about 3L so I would probably go with somewhere between 3L to 5L depending on what works for you in your design.
Going back to my original concern can I take it that all NE123W~04s are the same and it is just the spec sheets and figures that different suppliers quote that are different
If you're using the driver as a mid, well out of the Fs or Fb band, it wont matter as much how big the mid "chamber" (or enclosure) is.i purchased a few ne123s a couple of years ago and remember then being in the mid 50s Fs after break-in. I cant imagine them being much off of that spec now. If the Vas is in the single digits, you'd be ok with a 1.5 -2 liter chamber using it as a mid. Its more important to have an appropriate chamber shape than specific volume for midrange dampening purposes, so if you design the chamber somewhat acoustically correct, the chamber volume will fall into place automatically anyways.
Well, that's a good question. I'd have to pick the D75MX41, mainly because I'm a big fan of it and love its musicality, transparency and effortless sound in a large system. It has to be crossed rather high around 800 hz at least LR2 and needs a correct small rear chamber with lots of dampening to bring down Qts and allow better power handling. You really have to know what you're doing with this mid to get the best from it. Very disappointing if used the wrong way, but be patient and do your homework, it will reward.
The NE123 is way easier to cross over, has way more useful range and decent resolution for a cone mid. Having very musical midrange, it has just the right amount of resolution and isn't clinical sounding. The overall sound is engaging with all types of music and passes my critical piano music test with ease, as do the NE149 and NE180. It will handle a reasonbly low crossover point and has minimal power compression compared to other similar sized drivers. The titanium VC former and copper cap is unheard of at the price point. Its hard to beat for the money, sort of a budget revelator. The big negative with this driver (and the other NE series drivers) is the deep cone profile. This driver will perform decently on a WG, but needs a phase plug due to the deep cone.
If you're in the market for a dome mid and want that sound, there's no substitute. The only other type of driver that delivers this type of sound is a compression driver on a really good WG, oddly enough. There are many capable cone mid drivers, but most don't have that magic of a good large dome. The only 3" dome mids better than the D75MX41 are the ATC and Tang Band, both NLA.
The NE123 is way easier to cross over, has way more useful range and decent resolution for a cone mid. Having very musical midrange, it has just the right amount of resolution and isn't clinical sounding. The overall sound is engaging with all types of music and passes my critical piano music test with ease, as do the NE149 and NE180. It will handle a reasonbly low crossover point and has minimal power compression compared to other similar sized drivers. The titanium VC former and copper cap is unheard of at the price point. Its hard to beat for the money, sort of a budget revelator. The big negative with this driver (and the other NE series drivers) is the deep cone profile. This driver will perform decently on a WG, but needs a phase plug due to the deep cone.
If you're in the market for a dome mid and want that sound, there's no substitute. The only other type of driver that delivers this type of sound is a compression driver on a really good WG, oddly enough. There are many capable cone mid drivers, but most don't have that magic of a good large dome. The only 3" dome mids better than the D75MX41 are the ATC and Tang Band, both NLA.