X15 measured |
Post Reply |
Author | |
Timber_MG
Registered User Joined: 27 March 2004 Location: South Africa Status: Offline Points: 1454 |
Post Options
Thanks(0)
Posted: 22 April 2005 at 8:36pm |
Alright, here are some fairly rough measurements done indoors. The dip
around 800Hz is partly exaggerated by a floor-reflection. The divisions
are 3dB (not 10 as many are used to) and as a whole the PAP VX1 passive
x-over is well done. Perhaps one should make the ports a little
shorter, as this X15 has a tuning requency in the mid-low 40s (nice for
full-range use with eq)
Many thanks to Nexus for hosting. Let me know if you want me to remove img tags and replace with links. Response on-axis Response 20 degrees off-axis LF response (free-air) mic 3mm from dustcap mic inside port waterfall plot (NB: linear frequency scale!!!) Good night Martin |
|
JD01
Young Croc Joined: 23 August 2004 Status: Offline Points: 819 |
Post Options
Thanks(0)
|
@ Timber: Can't you set the waterfall to log frequency and longer time than 3ms? It's hard to say something about the decay in the lowmids... Anyways, the resonance around 10kHz looks pretty bad.... and above 14kHz it just gets nasty. Maybe one should take the HF out at 14kHz. Seems there is no sense putting energy in that range into the driver... |
|
Timber_MG
Registered User Joined: 27 March 2004 Location: South Africa Status: Offline Points: 1454 |
Post Options
Thanks(0)
|
Heya
I will post some more measurements, but I am rather limited by the gating measuring indoors. Have to take it outdoors and put it on stands which I don't have here yet (I don't measure at home due to blessed family) and I don't intend to hoist it up a tree like i do with raw drive-units. Since I went passive I have switched compression driver back to the BM-D450 (will nicht Perlen vor dir Säue werfen) The sound is a touch grainy up top, true, but not at all bad. For the intended application,they are well above average I must say, though a lower crossover (meaning diferent driver) would do them quite well. I have measureed "hi-fi" speakers that are much worse in all fairness. Unfortunately ETF doesn't do Log scale waterfalls. I will post some more measurements so that one can compare things when I get around to it (perhaps late today) Edited by Timber_MG |
|
Timber_MG
Registered User Joined: 27 March 2004 Location: South Africa Status: Offline Points: 1454 |
Post Options
Thanks(0)
|
And some measurements of a 12"/1" I find good enough to listen to as a
hi-fi (not perfect but show me the "hifi" that can do such dynamics
short of a large-format studio monitor). Box resonance is very dificult
to get rid off and is really evident at some lower frequencies as is
evitent in a close-up measurement. The driver itself (Winner 12S) is
quite well behaved up to 1.8kHz
|
|
JD01
Young Croc Joined: 23 August 2004 Status: Offline Points: 819 |
Post Options
Thanks(0)
|
Well, I can't tell that much about the 12" from the waterfall. For that the resolution below 2kHz is to bad in linear scale.... Highs above 4kHz look pretty good. What driver/horn is it? I can't believe that ETF can only do linear waterfall. Makes it pretty useless.... |
|
Timber_MG
Registered User Joined: 27 March 2004 Location: South Africa Status: Offline Points: 1454 |
Post Options
Thanks(0)
|
D2544 on H975. I can change the range to 200-2k, but I don't have
enough clean impulse response to make that sensible to display at all.
Another problem is getting enough s/n above computer noise in this
place (3 PCs running, only one of them even nearly quiet)
Waterfalls don't tell you all that much, energy distribution like these might tell you a little something. Still getting to grips with what information is actually meaningfull and what is a result of windowing smearing artefacts in a waterfall plot (and rectangular windowing is much too grainy) ETC for the Winner 12S post active crossover |
|
Timber_MG
Registered User Joined: 27 March 2004 Location: South Africa Status: Offline Points: 1454 |
Post Options
Thanks(0)
|
Note the reflection just after 5ms. Windowing (except rectangular)
effectively reduces that to 3.5 or so. So I could give you more than
that, but the floor reflection would just about ruin any of that
indoors. Outdors one coud get valid results up to somewhere (2kish) by
doing a half-space measurement with the mic on the floor.
|
|
JD01
Young Croc Joined: 23 August 2004 Status: Offline Points: 819 |
Post Options
Thanks(0)
|
Waterfalls are good for checking resonances and decay times. That's all, not much, but important...
|
|
tb_mike
Old Croc Joined: 01 October 2004 Location: New Zealand Status: Offline Points: 2744 |
Post Options
Thanks(0)
|
too bad about the linear scale and short time window. We all want to measure stuff,but it takes software,gear,time,and effort! Its abit much for me right now! Il have to get an ecm8000 when the exchange rate is favourable.
martin perhaps you could get the DEMO 30day trial of praxis or similar and compare for a sanity check? http://wiki16.parsimony.net/cgi-bin/wiki/program/db-view.cgi ?wiki27133;LoudspeakerMeasurement
You can go manual convolution with cooledit2000 + addon packs too. Edited by tb_mike |
|
Timber_MG
Registered User Joined: 27 March 2004 Location: South Africa Status: Offline Points: 1454 |
Post Options
Thanks(0)
|
I will not be near my X15s for the next two odd months I'm affraid. I
am using my 12"/1" Tops and my Achenbch 18s for a wedding of a friend
this weekend but will not get around to measure anything I'm affraid.
I will update this thread with better measurements sometime in the future when I get around to it. |
|
Post Reply | |
Tweet |
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |