I will trade you one TLAM cruise missile for a pair of PTT8.0X04 drivers... I am sure you could find a good use for the missile.
Actually I wish I could make the trade.
Does one just ignore this spike when filtering?
In comparison to the otherwise ruler flat T25B, what's up with the broad valley and rising response of the T25S?
Is this better used with steeper slopes?
You mean the spike at 50kHz? Hard to hear ;-)
The T25S membrane does not behave like a piston - you see this in the frequency response, esp. off axis.
Bliesma soft membranes are made for a typical sound and use thin/light material to get this.
I was under TLAM missiles when i was 14.
You don't want that on your hands. Trust me on this one.
Hi all, I was reading the HFC review of the Seas W18NX003 where it is explained that Seas' datasheet TSP values, where Fs is obtained with 2VRMS sine wave, are never going to agree with e.g. DATS/WT3, but are still objectively accurate.
Claus at Seas says:
"SEAS data is not replicated by low-voltage measurements. Nor will they comply with Klippel LPM data. In either case you will often see that the SEAS datasheet has a lower fs and softer suspension. The reason that the suspension becomes a bit softer at higher power input is due to stiction (a word for static friction). The reason we measure with such a power level is because we believe it is representative for the typical user case, provide some 85 dB of SPL, and therefore our data is more suitable for box simulation."
So does this mean that one should just use datasheet values for box design of any Seas driver?
Also, for crossover design in box, would one need to do anything different when measuring to obtain FRD and ZMA files?
Claus at Seas says:
"SEAS data is not replicated by low-voltage measurements. Nor will they comply with Klippel LPM data. In either case you will often see that the SEAS datasheet has a lower fs and softer suspension. The reason that the suspension becomes a bit softer at higher power input is due to stiction (a word for static friction). The reason we measure with such a power level is because we believe it is representative for the typical user case, provide some 85 dB of SPL, and therefore our data is more suitable for box simulation."
So does this mean that one should just use datasheet values for box design of any Seas driver?
Also, for crossover design in box, would one need to do anything different when measuring to obtain FRD and ZMA files?
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TSP is defined as low level "at-rest" speaker parameters. I would suggest that 2V parameters are stretching the definition of what we should call TSP. For some speakers, 2V free air may be exceeding xmax at low frequencies.
FWIW DATS v3 can operate up to 2V peak (5dBu), or anyone can build a simple resistor jig and measure impedance with REW or ARTA at any level you want.
I have compared speaker parameters determined at low voltage vs elevated voltage, and while the parameters will indeed be different for obvious reasons, the cabinet model came out the same, not different enough to care about anyway. YMMV. End result, use your measurements for your drivers for design, don't try to compare to the datasheet, just throw the sheet away. It's easy to compare speaker parameters determined at different voltage levels for yourself.
For crossover design, unless your crossover is near the driver Fs, there's not much to worry about.
The definition of TSP is "small signal parameter" - which means absolute linear behaviour of the speaker and very little membrane movement.
But that's not how we use our speakers ... cause we need a proper tuning at listening level and not at whispering level. With HiFi that's not a huge difference, more interesting with home cinema but important with PA subwoofers! They run warm when used, parameters shift significant.
I always measure TSP at different levels which is also a good thing to estimate the linearity of the driver. And always measure the tuning in the finished speaker and adapt if needed.
BTW - closed volumes are very unsensitive to TSP shifts, vented cabs with higher Q can change dramatic. With WinISD you can easily simulate a warm voice coil and remember - a voice coil can take temperatures to about 250°C before dying. These get hot!
But that's not how we use our speakers ... cause we need a proper tuning at listening level and not at whispering level. With HiFi that's not a huge difference, more interesting with home cinema but important with PA subwoofers! They run warm when used, parameters shift significant.
I always measure TSP at different levels which is also a good thing to estimate the linearity of the driver. And always measure the tuning in the finished speaker and adapt if needed.
BTW - closed volumes are very unsensitive to TSP shifts, vented cabs with higher Q can change dramatic. With WinISD you can easily simulate a warm voice coil and remember - a voice coil can take temperatures to about 250°C before dying. These get hot!
But the Purifis and Textremes, Is anyone aware of a class leading 6" midrange please with at least 90 dB 2.83V sensivity, please. Some Audiotecknologies exist but not as smooth I would hope.
Ok there are some Faitals and 18 thSounds mids that had good reviews but anything else for the ones having had the luck to listen to many units ?
Is Audax 17PR0Z0 always a good option today ?
Ok there are some Faitals and 18 thSounds mids that had good reviews but anything else for the ones having had the luck to listen to many units ?
Is Audax 17PR0Z0 always a good option today ?
The PHL 930 seems finee but I need 6" ! I do not wabt their 6" foamed surround or I would try the Revelator mid with foam suround... But do not want the mess 8 to 10 years after.
BMS 6" ? The faital 6RS140 despite good audioxpress review is not attracting to me due to its thd pick between 1k to 2k hz .
I would have chosen the Peereless tested here @HiFiCompass : NE-149w or NE-180W... but needs two for sensivity... MTM are not so good for the vertical dispersion !
BMS 6" ? The faital 6RS140 despite good audioxpress review is not attracting to me due to its thd pick between 1k to 2k hz .
I would have chosen the Peereless tested here @HiFiCompass : NE-149w or NE-180W... but needs two for sensivity... MTM are not so good for the vertical dispersion !
Thanks Jim, yep lurked about that two.... The 18THSounds has crazy good THD spec. The Revelator has averages but Revelator are always good balanced sound-wise : here that is the foam surround that makes me paranoiac about the ScanSpeak!
Btw, for the moment I am an active guy and I voice the loudspeaker since rigth with what is on the market in relation to the rest of my hifi : source and amp... 4 ohms makes the good caps need really expensive... it is not about power amp (I have a Chord powerplant
)
The bad thing : as soon as you go PA, passive is more difficult for EQ VS DSP ! Here the Revelator you pointed out makes sense, really... for passive filters guys. (but efficienty goes with the 4 ohms and still that f****d foam surround that badly ages)
Btw, for the moment I am an active guy and I voice the loudspeaker since rigth with what is on the market in relation to the rest of my hifi : source and amp... 4 ohms makes the good caps need really expensive... it is not about power amp (I have a Chord powerplant
)The bad thing : as soon as you go PA, passive is more difficult for EQ VS DSP ! Here the Revelator you pointed out makes sense, really... for passive filters guys. (but efficienty goes with the 4 ohms and still that f****d foam surround that badly ages)
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I’m not sure if modern foam surrounds are the same as the old, crumbly, ones.
The foam surround + edge treatment seem to mitigate the cone edge resonance you typically see in other drivers.
I have measured the NE180W and although it is a good value unit; the breakups means you need to throw more parts at it for a flat smooth response, with a passive crossover. IMHO probably why it was never a big hit. Oh and soon it is unobtainable.
I feel the modern version of the classic paper unit from SS is better (and available) ie. 18W/8542-10
Recent test from Klang & Ton:
The foam surround + edge treatment seem to mitigate the cone edge resonance you typically see in other drivers.
I have measured the NE180W and although it is a good value unit; the breakups means you need to throw more parts at it for a flat smooth response, with a passive crossover. IMHO probably why it was never a big hit. Oh and soon it is unobtainable.
I feel the modern version of the classic paper unit from SS is better (and available) ie. 18W/8542-10
Recent test from Klang & Ton:
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Only when you need >95dBSpl sensitivity the PHL drivers have foam surrounds. The bass/mid drivers have normal surrounds (1220, 91,5dBSpl) or there are newer models with high sensitivity (1752NdU).
Midrange drivers like 1120 are used in the biggest studio monitors - I'm not aware of a problem with the foam surround there but of course it's more sensitive as rubber.
I searched for the "perfect" 8" driver for an other project ... when I would have started with PHL I would have saved a lot of time and the cost of 4-5 sample drivers. They own their great reputation for a reason. These drivers not only stay low in THD with high level but also have very low THD at low levels - compareable to the best ScanSpeaks but 6-10dB more max level.
Midrange drivers like 1120 are used in the biggest studio monitors - I'm not aware of a problem with the foam surround there but of course it's more sensitive as rubber.
I searched for the "perfect" 8" driver for an other project ... when I would have started with PHL I would have saved a lot of time and the cost of 4-5 sample drivers. They own their great reputation for a reason. These drivers not only stay low in THD with high level but also have very low THD at low levels - compareable to the best ScanSpeaks but 6-10dB more max level.