Seleniums. I was quite surprised when I simulated these units, not out of this world they seemed.
/Erling
/Erling
Well ,smile is back again on my ugly face 😀...Alphas r now playing well ,just that sensitivity issue now becomes questionable...My small Trends is pushing this system on reasonably loud level.However, i would like to try that 15PW3 in my setup...is there anyone who heard and compared both driver?
chakija said:
in box they're pretty the same ( large 220L box I tried once ) ; now you see that with these things you can't be sure 'till you try them in vivo ;
I told ya that you're overreacting too early
Published curves do not have very much to do with OB-response, but that is another question ! I think you should explore the Alpha 15s, you won't do any better with any other bass-unit if you are after a balanced even response. Otherwise you could just try any unit you come across !
/Erling
/Erling
skorpion said:
I wrote " just for fun " - you see that's for closed box ......... even if 16m^3 big
but - difference between Alpha 15 and Sel PW12 can't be seen in graphs published on net ....... except sweeps from third party .....
Zen Mod,
I suppose anybody can show his ignorance here.
You just have to use the rigtht simulation programme to see the difference. Even if you sink down into 16 m3.
/Erling
I suppose anybody can show his ignorance here.
You just have to use the rigtht simulation programme to see the difference. Even if you sink down into 16 m3.
/Erling
skorpion said:
especially me 😉
skorpion said:
I don't have time ( sorry ) to look for sim progs for OB , lately ....... what I meant is just to make comparison between these drivers in same conditions ....... not trying to emulate OB ; of course that IB never can be same as OB , and vice versa .
tell us just one thing - it's obviously clear to you , but for us isn't
- which Selenium PW driver you mention here in superlatives - 12PW or 15PW ?and - is it good in simulation , or you tried it in vivo - too ?
Hi Zen Mod,
Good Spirit ! In fact I actually simulated the Selenium 12W3 when this was talked about. It will have a remarkable efficiency in OB but not streching down very low in frequency. Overall I would say that the Alpha15, like MJK has shown, will have quite a flat response down to 40 Hz in the baffle we are talking about. The Beta 15 will also be good not reaching flat as low as Alpha15 but may be with drier bass. As always with loudspeakers you have to compromise ! I never heard Selenium, Alpha15 or Beta15, I have used this unit for OB, also extremly linear down to 42 Hz: http://www.traumboxen.de/ad-audio/r1524.htm
/Erling
Good Spirit ! In fact I actually simulated the Selenium 12W3 when this was talked about. It will have a remarkable efficiency in OB but not streching down very low in frequency. Overall I would say that the Alpha15, like MJK has shown, will have quite a flat response down to 40 Hz in the baffle we are talking about. The Beta 15 will also be good not reaching flat as low as Alpha15 but may be with drier bass. As always with loudspeakers you have to compromise ! I never heard Selenium, Alpha15 or Beta15, I have used this unit for OB, also extremly linear down to 42 Hz: http://www.traumboxen.de/ad-audio/r1524.htm
/Erling
A&D R1830 looks pretty good too 😉
Saved that link, thankyou!
Wow, there is an 28" (Kics), but expencive fore a Korean driver
Saved that link, thankyou!
Wow, there is an 28" (Kics), but expencive fore a Korean driver
Eminence Delta15A data..............
Since this is an Eminence related thread I decided to put it here...
I couldn't get the Alpha as they don't stock them here anymore.
So I have only the Delta 15A to work with.
Here are some measurements with the stock driver with and without an external series resistor.
Column 1 was with the rear port on the driver closed.
Column 2 was with with the port open.
All others are with open port and external resistors as mentioned.
This driver will need a lot of equalisation . However I do expect the bass to sound good. Fs is also nice an low. Column 5 is suspect. Maybe the port was partially covered.
My baffle is 18x35 inches . Nothing has been installed yet.
The plan is to put in the drivers that I have. A Vifa D27DT dome tweeter , a Peerless 8 inch 850490 or a Vifa P17JW 6 inch driver and the Delta 15A .
Currently I am still trying to decide if I should first try out a Peerless 830537 12 inch bass before the Delta 15A (?). That way the cut out will just need to be enlarged. The Peerless has a Qts of 0.61 and Fs below 30hz.
Since this is an Eminence related thread I decided to put it here...
I couldn't get the Alpha as they don't stock them here anymore.
So I have only the Delta 15A to work with.
Here are some measurements with the stock driver with and without an external series resistor.
Column 1 was with the rear port on the driver closed.
Column 2 was with with the port open.
All others are with open port and external resistors as mentioned.
This driver will need a lot of equalisation . However I do expect the bass to sound good. Fs is also nice an low. Column 5 is suspect. Maybe the port was partially covered.
My baffle is 18x35 inches . Nothing has been installed yet.
The plan is to put in the drivers that I have. A Vifa D27DT dome tweeter , a Peerless 8 inch 850490 or a Vifa P17JW 6 inch driver and the Delta 15A .
Currently I am still trying to decide if I should first try out a Peerless 830537 12 inch bass before the Delta 15A (?). That way the cut out will just need to be enlarged. The Peerless has a Qts of 0.61 and Fs below 30hz.
My memory tells me that an OB does not have any benefit from room gain. Correct me if I am wrong. Using Basta it looks like I need about 10 or 12db lift at 30 Hz.
Active filters will be the best way to go about this to maximise the performance of the amp. Otherwise we will be throwing away part of the amplified signals in the passive crossover.
I'll have to start with some 'in room' measurements I guess.
Cheers.
Active filters will be the best way to go about this to maximise the performance of the amp. Otherwise we will be throwing away part of the amplified signals in the passive crossover.
I'll have to start with some 'in room' measurements I guess.
Cheers.
I spend last two days playing with XO and tried to listen to mids without any other speaker playing, and i even tried how does the beta 15 sound when used with boucherot and only with tweter and here is what i figured:
A6 by itself sounds awful with only 60uF.
Beta 15 makes great relaxed sound with so nice dynamics.
Tweeter is f**king good.
I was just about to set it back to "default" setup, but then it struck me. How about choking the A6 higher? So i tried 60uF, no significant change. Then i tried 20uF and the result was so much nicer sound with less distortion.
(other parts are 3.7mH on B15, 1.36uF on APT80)
I'm not trying to say it is more balanced now or anything like it. I just got rid of something that was bugging me in vocals. Its not perfect either - i suggest you guys try it too. It could be also a good idea to make the XO second order or something.
Next thing i'm going to do is add A15 and maybe try some cheap drivers for mids (4 per side). Last thing is new Selenium tweeter for forward firing and plate APT so it fires backwards.
Chakija, how is your OB?
Edit: trying without coil on Beta 15
A6 by itself sounds awful with only 60uF.
Beta 15 makes great relaxed sound with so nice dynamics.
Tweeter is f**king good.
I was just about to set it back to "default" setup, but then it struck me. How about choking the A6 higher? So i tried 60uF, no significant change. Then i tried 20uF and the result was so much nicer sound with less distortion.
(other parts are 3.7mH on B15, 1.36uF on APT80)
I'm not trying to say it is more balanced now or anything like it. I just got rid of something that was bugging me in vocals. Its not perfect either - i suggest you guys try it too. It could be also a good idea to make the XO second order or something.
Next thing i'm going to do is add A15 and maybe try some cheap drivers for mids (4 per side). Last thing is new Selenium tweeter for forward firing and plate APT so it fires backwards.
Chakija, how is your OB?
Edit: trying without coil on Beta 15
Well ,i am stuck at this moment because my cd player is broken.I got some vintage amplifier in not so good condition and i am using it with signal generator to brake in alpha 15''s some more.
I was quite satisfied with sound until i hooked this denon PMA-770 instead of Trends 10.1 .It sounded ,without any doubt ,worse than TA ,but something in bass and treble made me think that my current amp is not capable of pushing this speakers.It's just too thin in bass and not enough "sharp" in highs.Meantime ,i remodeled my selenim tweeter's crossover and now it plays with more extension and focus.I found it's schematics on Bottlehead forum...
I am planning to tweak my sony x222es ,and replace laser if needs to.There are also plans to get new amplifier or try to mod current one in order to get lower&louder bass extensions and right amount of treble.Also ,i plan to kick my parents out of their bedroom (~27m^2) and settle in with my system 😀 .Mids and highs sound so better in large room and i feel need 4 space along with my Alpha 15"
I was quite satisfied with sound until i hooked this denon PMA-770 instead of Trends 10.1 .It sounded ,without any doubt ,worse than TA ,but something in bass and treble made me think that my current amp is not capable of pushing this speakers.It's just too thin in bass and not enough "sharp" in highs.Meantime ,i remodeled my selenim tweeter's crossover and now it plays with more extension and focus.I found it's schematics on Bottlehead forum...
I am planning to tweak my sony x222es ,and replace laser if needs to.There are also plans to get new amplifier or try to mod current one in order to get lower&louder bass extensions and right amount of treble.Also ,i plan to kick my parents out of their bedroom (~27m^2) and settle in with my system 😀 .Mids and highs sound so better in large room and i feel need 4 space along with my Alpha 15"
Nice bedroom chakija! A bit bigger than our living room🙂.
I'm using the last XO setup (Boucherot on woofer, 20uF on mids and 1.38uF on tweeter) and am very satisfied with it. No way i'm going back with these drivers.
Though i could settle with this setup, its xmas and i ordered 8 cheapo 6" mids to try diamond setup for mids to try with lower XO point than now (1kHz). More like 2nd order @250-500Hz.
The diamond pattern: http://www.dnaudio.com/DNA-Sequence-Speakers.html (of course my version will be OB)
I'm using the last XO setup (Boucherot on woofer, 20uF on mids and 1.38uF on tweeter) and am very satisfied with it. No way i'm going back with these drivers.
Though i could settle with this setup, its xmas and i ordered 8 cheapo 6" mids to try diamond setup for mids to try with lower XO point than now (1kHz). More like 2nd order @250-500Hz.
The diamond pattern: http://www.dnaudio.com/DNA-Sequence-Speakers.html (of course my version will be OB)
ashok said:
Yes and No.
An active filter is a good way to go - just remember that you need a lot more voltage gain out of your amp when you use one. The same is true of a passive solution. Either way, you have to throw more voltage at the speaker to get the balance right.
Let's say we use a 12dB boost in the low end for our OB.
With a fully active filter you will be boosting the low end up by 12dB. So when you bring the mids to a normal listening level, the low end will be 12dB higher (relatively). Your amp better have that extra 12dB headroom, or you'll be clipping. With a powerfull amp and a good power supply, that's not a big problem.
With a passive line level filter you can't boost - only attenuate. So now the highs and mids are 12dB lower than the bass going into the amp. (Probably more, because of the way the filter works). Your amp will still need enough headroom to provide for that 12dB difference, as well as plenty of voltage gain. You have to make up for the voltage losses, remember? So you need more gain.
If you use a speaker level filter, it still works out the same. You are throwing away voltage in your filter, so you have to have that voltage there in the first place. Comes out the same really, you have to have the extra headroom.
So no matter which way you look at it, you need more voltage than normal in the bass to overcome the Open Baffle losses. More voltage into the same speaker equals more power, of course.
I hope all the above is clear - but probably not. 😉 Maybe I should make some graphs.
An active filter is a good way to go, but just remember that no matter what you do, your amp will need more headroom than it would with a "normal" speaker - to achieve the same levels. How much more headroom depends on how much bass boost.
Don't forget that a typical 12dB boost means you need 16X more power in the low end. That is the "dirty secret" of Open Baffle.
"..............no matter which way you look at it, you need more voltage than normal in the bass to overcome the Open Baffle losses..............."
Absolutely right .
The response of the woofer can be seen as a mid/HF cut or a bass boost , depending on which frequency is taken as a reference point. The active filter will throw away ( low power ) voltage but at the power amp , depending on the passive crossover used , there is potential to loose larger amounts of power than in the active circuit.
But yes, the amp will need a larger headroom than usual because the 'shaping' of the woofer response inherently reduces system sensitivity and also needs to fill in the low frequency end with a bass lift .
Does anyone using the Eminence Alpha 15A use any electronic equalisation to prop up the bass ? The simulation seems to show that it holds up very well up to about 40 Hz.
Absolutely right .
The response of the woofer can be seen as a mid/HF cut or a bass boost , depending on which frequency is taken as a reference point. The active filter will throw away ( low power ) voltage but at the power amp , depending on the passive crossover used , there is potential to loose larger amounts of power than in the active circuit.
But yes, the amp will need a larger headroom than usual because the 'shaping' of the woofer response inherently reduces system sensitivity and also needs to fill in the low frequency end with a bass lift .
Does anyone using the Eminence Alpha 15A use any electronic equalisation to prop up the bass ? The simulation seems to show that it holds up very well up to about 40 Hz.
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