It's unfortunate that you felt the need to go all PC and somewhat dismiss your own observations.
They were honest and are indeed relevant ( & hint at an apparent paradox ) .
Moving on, even JBL Pro in their new Superlative M2 Studio Monitor ( employing an "all-electronic" network ) decided to include a passive RC network // to first pad the horn driver down to the level of the woofer ( while somewhat restoring the HF content by using an inline "bypass" capacitor /strapped over the Lpad ).
What might you think it is ( that we PRO users ) recognize in the inherent power of the passive component ?
- In a phrase, "dynamics, re-balancing" .
- The lowly RC network goes a long way to audibly ( soft ) compress the mid-range area untouched by the capacitor HF bypass.
- Resistors do more than just benignly pad down level.
In conjunction with the HF bypass, the padding network does help the horn driver become a smidge more "tweeterish" in it's performance.
🙂
Btw, does the RLC to tame the main impedance peak is usefull too ? Or not realy for a tweeter, be it compression drive or not, because it's simple to deal with for an amp ? (no consequence for the sounding result I mean) ?
Series LCR's ( strapped across a driver ) when implemented as notch-filter ( ie; working within some resistive isolation from the amplifiers source impedance ) offer a frequency band-specific form of soft-compression ( in addition to their frequency attenuating duties) .
( IME ), a Series LCR ( strapped across the outputs of an amp ) when implemented as an impedance equalizer, hasn't offered any audible benefit (with the Pro amps that I typically have used over the last 40 years / ie; Crown, Phase Linear, QSC, Bryston, BGW, etc ).
Perhaps they ( impedance equalizers ) work better with amplifiers that struggle with dynamic linearity ( I have little experience with those types ) .
🙂
( IME ), a Series LCR ( strapped across the outputs of an amp ) when implemented as an impedance equalizer, hasn't offered any audible benefit (with the Pro amps that I typically have used over the last 40 years / ie; Crown, Phase Linear, QSC, Bryston, BGW, etc ).
Perhaps they ( impedance equalizers ) work better with amplifiers that struggle with dynamic linearity ( I have little experience with those types ) .
🙂
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Thanks, so it can be thought as a sort of shyer FR notch effect but without a //LCR putted in serie with the signal (which is more expensive being in signal because of the good quality parts cost).... I have really to measure the impedance of my tweeter 🙂 to try if I hear a benefit VS the FR notch I have ! 😎
If I was wiring up a BMS 4550 ( on a SEOS12 ) into a high-efficiency (home) audio system I would wire-up the following ( compensation circuit for the driver ) and give it a listen.
🙂
🙂
Earl I'm not quite sure how to read some of your other comments (and AllenB's), I'm not rushing into anything and there isn't an "issue", I'm interested in testing out a few different CD's to see how they sound as the DE250 is the only CD I've ever spent any real time with, as simple as that.
It appears that some of you don't believe there can be a better sounding driver than the DE250? -if that's your position then I'm happy to accept that, but I am still looking for suggestions as well.
I will give your circuit a try as I was already considering trying a Zobel , I do appreciate that input.
Thanks!
Javad
It appears that some of you don't believe there can be a better sounding driver than the DE250? -if that's your position then I'm happy to accept that, but I am still looking for suggestions as well.
I will give your circuit a try as I was already considering trying a Zobel , I do appreciate that input.
Thanks!
Javad
Please let us know how you get on. I'll be curious to hear if it sorts out the slight harshness and if you notice any sound quality improvements with other CDs.
Geddes is, I think, using the neo version DE500 now - but not claiming big audible differences - although he seems to think the shorter throat is better in general than other CD
reduced size/mass helping mounting/resonance issues
reduced size/mass helping mounting/resonance issues
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JShadzi, that looks very nice, but as you have an easily changed EQ, you might also want to try putting in a gradual high frequency downward slope (of a few dB, maybe up to 6dB total) starting somewhere around 1 or 2kHz. Largely because we are in domestic rooms that emphasize highs, but also because a lot of music is mixed expecting such a response -- the spectra given us by recording and mastering engineers isn't a scientific clone of reality, it's an artistically-flavored (even if only by choice of microphones) product meant to please (and to sell).
@bwaslo thank you for the comment, I'm familiar with the downward sloping EQ, I have a few different configurations I play with, for me personally the downward slope does not sound good with most material. I prefer the sound of a more flat response above 1khz. I also like a downward slope from 20hz to 1k.
To your point different music is mastered differently so I also have some tone controls that I can use to optimize the sound of anything I'm listening to.
Thanks!
Javad
To your point different music is mastered differently so I also have some tone controls that I can use to optimize the sound of anything I'm listening to.
Thanks!
Javad
Another vote for the Beyma CP380M - I went to these from Scanspeak revelator domes and was pleased with how smooth / sweet they were. Maybe not as 'detailed' as the domes but in no way harsh.
I'd go along with one of the posts above about making sure the mid drivers aren't the cause of any harshness as in one of my projects a pair of precision devices 10" mids were awful due to cone breakup, even with a 4th order high pass.
Looking at your posted frequency response I'd expect it to sound a bit sharp due to a lack of midbass. Maybe try to get a flat response outside and see how it sounds when you move it back indoors. (expect a response that is a lot higher up to ~300Hz then drops and stays fairly flat to ~6K )
I'd go along with one of the posts above about making sure the mid drivers aren't the cause of any harshness as in one of my projects a pair of precision devices 10" mids were awful due to cone breakup, even with a 4th order high pass.
Looking at your posted frequency response I'd expect it to sound a bit sharp due to a lack of midbass. Maybe try to get a flat response outside and see how it sounds when you move it back indoors. (expect a response that is a lot higher up to ~300Hz then drops and stays fairly flat to ~6K )
HOW I WOULD SPEND YOUR MONEY....
Build a new sealed box optimized for a 12" midbass using your (SEOS12 + B&C DE250) crossed LR4 at 1300Hz...don't forget time alignment. Put it next to your woofer for good integration plus baffle step compensation. Don't let woofer box vibrate mid-tweet.
-Eminence Delta Pro12A is used in Fusion12 from DIY Sound Group. $130
-Faital 12FH530 $250
-Acoustic Elegance TD12M $350
Build a new sealed box optimized for a 12" midbass using your (SEOS12 + B&C DE250) crossed LR4 at 1300Hz...don't forget time alignment. Put it next to your woofer for good integration plus baffle step compensation. Don't let woofer box vibrate mid-tweet.
-Eminence Delta Pro12A is used in Fusion12 from DIY Sound Group. $130
-Faital 12FH530 $250
-Acoustic Elegance TD12M $350
Hah @LineSource, where were you when I started this thread? 😛
http://www.diyaudio.com/forums/mult...ut-3-way-pa-driver-project-advice-needed.html
Certainly the direction I'll likely take with my next horn project, this won't be my last project, but for the time being I've having fun with this one, and at this stage I just want to experiment with a few different CD to see which one I like the best. I also have 2 other projects I'm playing with as well simultaneously 🙂
So would you say the DE250 is the best CD in your opinion, nothing else out there you'd recommend looking into?
Thanks!
Javad
http://www.diyaudio.com/forums/mult...ut-3-way-pa-driver-project-advice-needed.html
Certainly the direction I'll likely take with my next horn project, this won't be my last project, but for the time being I've having fun with this one, and at this stage I just want to experiment with a few different CD to see which one I like the best. I also have 2 other projects I'm playing with as well simultaneously 🙂
So would you say the DE250 is the best CD in your opinion, nothing else out there you'd recommend looking into?
Thanks!
Javad
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The BMS 4550 measures slightly better than the DE250. For louder playback it's hard to beat larger diaphram drivers. My Ciare coaxials sound much smoother at high volumes despite having a compromised horn/throat structure.
Hi Javad,
Three drivers worth owning ( IMHO ) are ( the following order is based on diaphragm size ) ;
(A) In a 25mm diaphragmed compression driver : B&C de10
- This is another plastic ( mylar ) diaphragmed driver that has an EBP / ( torque curve ) / ( voice ) - that is higher than the drivers that follow in this list .
- It is the most tweeter like of the three, due to the smaller diaphragm size ( & therefore needs to be crossed-over higher / such as above 2500hz ).
- A clone of this driver is extensively used over at DIYSG in their smaller boxes ( like yours ).
(B) 35mm diaphragmed CD : Peerless ( by Tymphany ) DFM-2535R00-08
- This has a mid-sized diaphragm putting it's voice just outside of true tweeter range, though with the right RC compensation it is a nice compromise between a midrange driver & a tweeter .
- The plastic-coated, titanium diaphragm is a nice compromise between speed & damping.
(C) 44.45mm>1.75" diaphragmed CD : GPA ( Altec-derived ) 802-8G
- GPA 902-8A pdf cut-sheet
- Actually, for your SEOS waveguide the 902 ( ferrite magnet version ) is a better choice ( what with it's shorter throat ).
- Right now, they don't appear in the GPA web-store .
- It uses an aluminum diaphragm that employs the classic Harris-tangential surround. This combo is a classic legacy design & has it's own unique signature sound ( with just enough breakup in the UHF to fake a tweeters sparkly sound ) .
- FYI, GPA stuff is harder to come by / though worth the effort .
All of these 3 drivers will need passive optimization circuits ( as I have previously preached ) to be at their best ( produce the .frds & .zma files of drivers on waveguides & I'll spit out some compensation circuits for you ) .
🙂
Three drivers worth owning ( IMHO ) are ( the following order is based on diaphragm size ) ;
(A) In a 25mm diaphragmed compression driver : B&C de10
- This is another plastic ( mylar ) diaphragmed driver that has an EBP / ( torque curve ) / ( voice ) - that is higher than the drivers that follow in this list .
- It is the most tweeter like of the three, due to the smaller diaphragm size ( & therefore needs to be crossed-over higher / such as above 2500hz ).
- A clone of this driver is extensively used over at DIYSG in their smaller boxes ( like yours ).
(B) 35mm diaphragmed CD : Peerless ( by Tymphany ) DFM-2535R00-08
- This has a mid-sized diaphragm putting it's voice just outside of true tweeter range, though with the right RC compensation it is a nice compromise between a midrange driver & a tweeter .
- The plastic-coated, titanium diaphragm is a nice compromise between speed & damping.
(C) 44.45mm>1.75" diaphragmed CD : GPA ( Altec-derived ) 802-8G
- GPA 902-8A pdf cut-sheet
- Actually, for your SEOS waveguide the 902 ( ferrite magnet version ) is a better choice ( what with it's shorter throat ).
- Right now, they don't appear in the GPA web-store .
- It uses an aluminum diaphragm that employs the classic Harris-tangential surround. This combo is a classic legacy design & has it's own unique signature sound ( with just enough breakup in the UHF to fake a tweeters sparkly sound ) .
- FYI, GPA stuff is harder to come by / though worth the effort .
All of these 3 drivers will need passive optimization circuits ( as I have previously preached ) to be at their best ( produce the .frds & .zma files of drivers on waveguides & I'll spit out some compensation circuits for you ) .
🙂
Hard to believe that with all the inexpensive, or even free, loudspeaker measuring gear that is out these days that GPA can't manage to put a response curve or impedance curve in their data sheet!
Yep, seemingly marketed only to a clutch of true-believers .
Here's what I've collected through the years.
A closer look-see;
And the GPA 902-8A ( thanks to Zilch );
They are certainly not the smoothest drivers to work with ( but manageable ).
Here's an older 802-8D ( loaded with a 35480 diaphragm ) on the QSC ( 152i horn-clone ).
- This was an exercise in pushing downwards towards achieving a 1K crossover point , with reasonable padding ( while still reaching upwards for usable HF extension ).
🙂
Here's what I've collected through the years.
A closer look-see;
And the GPA 902-8A ( thanks to Zilch );
They are certainly not the smoothest drivers to work with ( but manageable ).
Here's an older 802-8D ( loaded with a 35480 diaphragm ) on the QSC ( 152i horn-clone ).
- This was an exercise in pushing downwards towards achieving a 1K crossover point , with reasonable padding ( while still reaching upwards for usable HF extension ).
🙂
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That's nothing to sneeze at. But the new (and cheap) Tymphany eats it for breakfast, in terms of smoothness at least! The 802G goes out a little further in frequency, though (appears to be in breakup, though).
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