Lafe Eric, it seems I was preaching to the converted! Carry on my friend 
If it is rising at that point, that will partly counteract the effect of your inductor.
Another way to look at it is it's only 2dB. Not trying to minimise that fact but one quarter sounds like a lot.
What you all say is all very true... but, at the same time, isn't it nice to know that not only can you add resistance, you also now have a method to take it away from the air core inductors in your passive crossovers? Something which, to my knowledge - and I have looked extensively - has not been done before in audio!
Yes, getting the right resistance can be important - I couldn't agree more.
Yes, getting the right resistance can be important - I couldn't agree more.
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Another way to look at it is it's only 2dB. Not trying to minimise that fact but one quarter sounds like a lot.
Another way of putting it is that the loss is barely above the level of perception.
FWIW, stacking a lot of inductors doesn't work as well as you'd think - I've done it and the coupling while reasonable drops off significantly as you add more stacked parallel inductors. Ask me how I know, and also it is not quite as unique as you might suspect, although they rarely leave the lab..
You might check out the Erse line of steel cored inductors - they're rated for 500W and presumably have significantly lower dcr than a comparable air core although I have not found a spec for dcr. Were it me I'd probably not worry too much about it, use the biggest air core I could reasonably afford, and make allowances in the speaker design for the dcr affecting QES as appropriate.
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Thanks for the tip Kevinkr.
Strange though, all I've read about all the "Horrible" things that air core coils do - turns out they aren't so bad after all. Turns out, it seems, we are all quite used to the "evils" of air core inductors, and it's really hardly worth noticing (or hardly noticeable)!
Ciest la vie.
Strange though, all I've read about all the "Horrible" things that air core coils do - turns out they aren't so bad after all. Turns out, it seems, we are all quite used to the "evils" of air core inductors, and it's really hardly worth noticing (or hardly noticeable)!
Ciest la vie.
Thanks for the tip Kevinkr.
Strange though, all I've read about all the "Horrible" things that air core coils do - turns out they aren't so bad after all. Turns out, it seems, we are all quite used to the "evils" of air core inductors, and it's really hardly worth noticing (or hardly noticeable)!
Ciest la vie.
Actually given the way I design my speaker systems I don't find the DCR a big issue and I much prefer the air core for their performance under duress, IMHO a saturated inductor in an X-O is a pretty evil sounding beast. I've seen nearly perfect square waves generated by over worked/under sized iron cored inductors at relatively modest power levels.) Also my experience is that the initial permeability (right term?) of the core may mean that the inductance is not constant at low signal amplitudes. For all their limitations I will take an air core any day over other sorts for X-O duty.
I should note I use air cores in my Onkens with Iconic 165-8G woofers which are essentially an Altec 515-8G - the efficiency is > 100dBspl - with LF room gain and 8Wrms per channel the system plays very loudly. The 20Wrms GM70 amps should be significantly louder..
Well, it would seem to me if efficiency utilizing low power was important it would be these types of things you would be watching - but you're the expert.
In fact, if I had the time and money to really put into something like this, I'm sure that's the route I'd take - perfecting every aspect with an eye to minimalism - but, as it is, I'm more of a brute force type person, pumping 200 watts into a 96 db efficient system. Well, really, I just want some decent tunes I can enjoy in a variety of circumstances - but you get the drift.
In fact, if I had the time and money to really put into something like this, I'm sure that's the route I'd take - perfecting every aspect with an eye to minimalism - but, as it is, I'm more of a brute force type person, pumping 200 watts into a 96 db efficient system. Well, really, I just want some decent tunes I can enjoy in a variety of circumstances - but you get the drift.
Well, it would seem to me if efficiency utilizing low power was important it would be these types of things you would be watching - but you're the expert.
In fact, if I had the time and money to really put into something like this, I'm sure that's the route I'd take - perfecting every aspect with an eye to minimalism - but, as it is, I'm more of a brute force type person, pumping 200 watts into a 96 db efficient system. Well, really, I just want some decent tunes I can enjoy in a variety of circumstances - but you get the drift.
Not quite an expert, now I think Cal or planet10 fit that description better than I..
The source impedance of my amplifier is about 2.5 ohms and the inductor is a little under 0.5 ohms, the box tuning was optimized for a source impedance of about 3 ohms. Onken design is a little, um obscure..
Noting also that the power I quoted is into 8 ohms despite the source impedance. SE amps are not that efficient unfortunately, but it all works together to get me what I intended.Now with an efficiency of 96dB, a loss of a couple of dB and 200W I think spls of > 114dBspl at 1m are going to be achievable - which is obscenely loud. (At these power levels I would expect some power compression in the VC of your woofers otherwise I might have said 120dB, how much and under what onset conditions I am not really sure.) I currently max out around 108dB (both speakers driven) at my listening position which is obscenely loud.. I think in normal listening activities the peak levels where I sit are probably not hitting 90dB very often. (The system can handle at least 10dB more power than I can provide giving you a hint of the available dynamic range.)
My goals also might be somewhat different than yours, although perhaps not so much. I have big boxes and JBL 2440 and 2402 handling the mids and highs
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I would focus my (your) attention to the HF a little more ,as you are describing what Brute Force can do ,relatively to the Bass Department which reproduces most of the power content of most kind of music .
But , luckily , we have Mids and Tweeters
Midrange driver should be placed ( also in OB ,with some acoustic damping behind...) on top of the bass cab and will have a very narrow shape ,because of the wavelenghts and primary reflections of the baffle ,so 8" is the maximum.
The rock solid imaging that a stereo set may give depends also from the reconstruction of the physical hall where the event was recorded ,so the great benefit of having little source point (such as mini-stand speakers)is that it disappears and the secondary reflections don't mess with the cabinet shape .
Then ... I really don't like that horn !!
I really like what Carpenter does with paper mache horns , and I think that you could achieve a fairly better quality in HF with a little effort .
WOW ! My English is improving
But , luckily , we have Mids and Tweeters
Midrange driver should be placed ( also in OB ,with some acoustic damping behind...) on top of the bass cab and will have a very narrow shape ,because of the wavelenghts and primary reflections of the baffle ,so 8" is the maximum.
The rock solid imaging that a stereo set may give depends also from the reconstruction of the physical hall where the event was recorded ,so the great benefit of having little source point (such as mini-stand speakers)is that it disappears and the secondary reflections don't mess with the cabinet shape .
Then ... I really don't like that horn !!
I really like what Carpenter does with paper mache horns , and I think that you could achieve a fairly better quality in HF with a little effort .
WOW ! My English is improving
LafeEric, I made a little check with the 2226's specs.
The VC winding height and the magnetic gap height give about 11mm of linear excursion.
I entered the excursion and effective piston diameter in that: Strassacker: Lautsprecher - Boxen - Selbstbau calculator.
And got a maximum of 105 db@30 hz
I guess the 120 db aim would require more linear displacement than that
See the attached screenshot.
The VC winding height and the magnetic gap height give about 11mm of linear excursion.
I entered the excursion and effective piston diameter in that: Strassacker: Lautsprecher - Boxen - Selbstbau calculator.
And got a maximum of 105 db@30 hz
I guess the 120 db aim would require more linear displacement than that
See the attached screenshot.
Attachments
I did that FS only governs how steep will be the fall below it, but does not forbid reproducing lower frequencies, it governs the way the SPL vs frequency graph shape.
Anyway the same calculator returns 112 db at 45 hz... 120 are reached at 70 hz. This alone tells a story of 30 hz @ -15 db (at high power) without considering further limitations such as cabinet, driver Fs and power compression...
Anyway the same calculator returns 112 db at 45 hz... 120 are reached at 70 hz. This alone tells a story of 30 hz @ -15 db (at high power) without considering further limitations such as cabinet, driver Fs and power compression...
Picowallspeaker: I definitely see an OB in my future - but this project isn't it. For the 'Classic 3 way' I intend to stick just to that - a big vented box with 3 drivers in it.
T101: Yes, I have had to accept that the bass extension with the 2226H isn't all that great. So far it looks to be about 200 litre tuned to 35 Hz - which means I won't get much below it.
I have been thinking about that a great deal, and will probably build an MTM with an actively crossed woofer for my next project.
Many have come to me with this or that suggestion to improve my project - often to build something other than what I am building. I understand and appreciate all your suggestions - but understand that I am NOT trying to build something ultimate or exotic here. Though this may be somewhat hard to fathom for many, this is more of a nostalgia project I am using to learn about speakers and building speakers. I want it to sound as good as it can, true, but I also deliberately intend for it to be an exploration of the conventional.
This is why I call it the 'Classic 3 way' - classic being in the context of 'representative of an age' or 'archetypal'. Classic 3 way = big speakers with three drivers in them driven by a simple stereo amp. That is what this project is, and that is what I am going to build.
In my job I have built many things, and usually only one. I know that the first time I build something I am basically just learning to build it. It is a sad truth to me that at the end of a project I look at it and see how I should have built it. This project is just that for me - a project to learn the basics on.
So, keep that in mind as we continue discussions. I do very much appreciate your criticisms and discussions, but this project is not try to go beyond the bounds of the conventional - it is to explore the conventional, to learn what the strengths and the limits of the conventional are, and yes how to go beyond those conventions and limitations when the time comes.
So, do not feel ignored if I decide not to utilize your suggestion for this project - I more than likely won't. Later on, however, when I have learned much more, then I will attempt to step to a higher level and all of your concern and thoughtful coaching will really bear fruit.
Thank you all in advance!
T101: Yes, I have had to accept that the bass extension with the 2226H isn't all that great. So far it looks to be about 200 litre tuned to 35 Hz - which means I won't get much below it.
I have been thinking about that a great deal, and will probably build an MTM with an actively crossed woofer for my next project.
Many have come to me with this or that suggestion to improve my project - often to build something other than what I am building. I understand and appreciate all your suggestions - but understand that I am NOT trying to build something ultimate or exotic here. Though this may be somewhat hard to fathom for many, this is more of a nostalgia project I am using to learn about speakers and building speakers. I want it to sound as good as it can, true, but I also deliberately intend for it to be an exploration of the conventional.
This is why I call it the 'Classic 3 way' - classic being in the context of 'representative of an age' or 'archetypal'. Classic 3 way = big speakers with three drivers in them driven by a simple stereo amp. That is what this project is, and that is what I am going to build.
In my job I have built many things, and usually only one. I know that the first time I build something I am basically just learning to build it. It is a sad truth to me that at the end of a project I look at it and see how I should have built it. This project is just that for me - a project to learn the basics on.
So, keep that in mind as we continue discussions. I do very much appreciate your criticisms and discussions, but this project is not try to go beyond the bounds of the conventional - it is to explore the conventional, to learn what the strengths and the limits of the conventional are, and yes how to go beyond those conventions and limitations when the time comes.
So, do not feel ignored if I decide not to utilize your suggestion for this project - I more than likely won't. Later on, however, when I have learned much more, then I will attempt to step to a higher level and all of your concern and thoughtful coaching will really bear fruit.
Thank you all in advance!
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Not sure how I would do that. Don't I have to be careful of rear reflections?
Do you have drivers picked out yet??Me too.High efficiency.
I measured closer to 48.
Yes, it will be loud - but the real benefit of this, IMO, is the potential dynamics!
with low BR tuning you might get problems with a gap between port tuning and actual driver output
problem with high BR tuning is that it looses complete control of frequencies below its tuning
apart from the highish Fs the likewise highish Qts makes it suitable for closed box
or else consider a low cut filter, as used in pro PA systems
for a design and goal like this I wouldn't mind using a 'simple' graphic EQ
problem with high BR tuning is that it looses complete control of frequencies below its tuning
apart from the highish Fs the likewise highish Qts makes it suitable for closed box
or else consider a low cut filter, as used in pro PA systems
for a design and goal like this I wouldn't mind using a 'simple' graphic EQ
Ah. Yes, that all makes sense.
In consideration of something like that one of the reasons I want such high efficiency and high power handling isn't (just) to blow out my neighbors.
Then again it may make very little difference, if any - but again again I am forced to consider the limitation of the format, and try to plan accordingly, as best I can.
Lowpoke asked for a picture, so...
Nice thread, classic 3 way, high efficiency... Open baffle is not. thanks
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