"So your 6.5" midwoofer is sized for use as a lower midrange in a possibly high performance 4 way or a modestly performing 2 way with resonance issues at the high frequency end of the passband and inadequate SPL at the low."
Your comments about LF performance seem a little cautious in relation to the impressions I've been getting from my reading. Perhaps that's neither here nor there. More importantly, do your comments pertain simply to the raw data for these drivers, or do they take account of what might be achieved with either a port or PR's?
"Filler drivers have little to no passband and are something of a bodge to handle the inadequacies of passive crossovers. A competent implementation would be an improvement over the underlying 2 way but inferior to a competent implementation of a conventional 3 way with more appropriately sized drivers and more evenly balanced passbands. (In the absence of a design this is speculation on how your 2.5" driver may be used between a 6.5" midwoofer and a large 1.5" tweeer.)"
I'm assuming that you place the SBA dome mid as belonging firmly in the category of "filler". If so, then the nature of your comments leaves me wondering why SBA would take the trouble to design and produce them! Can you comment on any positive characteristics?
"The price would seem to place them more in the boutique audiophile category .."
There may well be some truth in that. Perhaps I am naive in thinking that the price also relates to the LF performance that it can produce from smaller cabinets, which (most people seem to agree) is not an easy task.
Your comments about LF performance seem a little cautious in relation to the impressions I've been getting from my reading. Perhaps that's neither here nor there. More importantly, do your comments pertain simply to the raw data for these drivers, or do they take account of what might be achieved with either a port or PR's?
"Filler drivers have little to no passband and are something of a bodge to handle the inadequacies of passive crossovers. A competent implementation would be an improvement over the underlying 2 way but inferior to a competent implementation of a conventional 3 way with more appropriately sized drivers and more evenly balanced passbands. (In the absence of a design this is speculation on how your 2.5" driver may be used between a 6.5" midwoofer and a large 1.5" tweeer.)"
I'm assuming that you place the SBA dome mid as belonging firmly in the category of "filler". If so, then the nature of your comments leaves me wondering why SBA would take the trouble to design and produce them! Can you comment on any positive characteristics?
"The price would seem to place them more in the boutique audiophile category .."
There may well be some truth in that. Perhaps I am naive in thinking that the price also relates to the LF performance that it can produce from smaller cabinets, which (most people seem to agree) is not an easy task.
It follows from the laws of physics with respect to the required volume displacement (surface area * stroke) to reproduce low frequency transients cleanly in the direct sound heard at a few metres away from speakers when playing music at standard listening levels in a room that is not booming.
So why do many claim that inadequately sized drivers are fine? Firstly, many people listen more quietly than standard levels (the levels in a cinema) with the subsequent loss in perceived detail and relatively reduced high and low frequencies. Which is fine but it isn't high fidelity. Secondly, they listen in the presence of 20 dB or so of room boom which not only raises the level of (some) of the low frequencies but makes the sound unpleasant leading to a tendency to back off with the volume control. Again fine but it is not high fidelity.
Using resonances (ports, passive radiators,...) to raise the level of the lowest frequencies tends to be fine when they operate at frequencies below the significant transient content in the music when whatever may be present tends to be more sustained. Resonators tuned to 20-35 Hz are likely to be fine but as the tuning frequency is raised as is often the case for small midwoofers it may start to become noticeable. Again this assumes what is heard is not dominated by a +20 dB room resonances which will swamp any small resonances the speaker may be seeking to exploit.
They produce them because they see a demand that will enable them to make a profit. There are growing numbers of drivers produced to satisfy the retro or audiophile market rather than the high fidelity one. There is of course nothing wrong with wanting ones luxury goods to satisfy something other than cold dry technical performance.
One can use motional feedback and other things to raise the clean output of a driver but one needs pretty compelling size constraints for the additional cost and complexity to be worthwhile. Without one competent designs will simply use appropriately sized drivers for the task.
My suggestion is to see the presence of the Purifi driver in a wider context.
The designers (Putzeys a.o.) are into relatively small, DSP controlled/corrected, class D amplifier driven expensive loudspeakers (think of Kii for example).
Especially when using multiple drivers, it is possible to create a "big sound" into a relatively small enclosure thanks to high Xmax and a low distorsion motor.
IMO for a more or less classical passive 3-way you should look elsewhere; enough suggestions have been given.
Your wallet will thank you....
The designers (Putzeys a.o.) are into relatively small, DSP controlled/corrected, class D amplifier driven expensive loudspeakers (think of Kii for example).
Especially when using multiple drivers, it is possible to create a "big sound" into a relatively small enclosure thanks to high Xmax and a low distorsion motor.
IMO for a more or less classical passive 3-way you should look elsewhere; enough suggestions have been given.
Your wallet will thank you....
Thanks for this all too concise and clear summary, daanve. Your point is well taken and your patience appreciated. It's true that there have been plenty of suggestions for a "more or less classical passive 3 way", but few of these, if any, seem to have attracted any consensus whatsoever on this thread. For example, some promising 2.5 ways, e.g. TG761 and indeed the compact 3 way, Ekta 11, have come with dire warnings and strictures attached. Fewer, if any at all, have referred to compact, dual woofer designs - perhaps I've missed one and should take another look. The nearest I can find to an implicit consensus seems to be that unless I'm prepared to get into serious room treatment and/or DSP, I shouldn't be considering thoughtfully designed speaker "kits", regardless of their design.
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Try to find out what type of loudspeaker would fit your listening room best.
Don't expect any consensus on audio forums; non-consensus is why they are there....
Apparently I am missing the "consensus" that you should avoid speaker kits without being prepared for room treatment/DSP. Anyway I disagree.
Don't expect any consensus on audio forums; non-consensus is why they are there....
Apparently I am missing the "consensus" that you should avoid speaker kits without being prepared for room treatment/DSP. Anyway I disagree.
If you were designing high fidelity 3 way main speakers for use in the home without any significant constraints beyond not being excessively large, expensive, heavy, ugly, inefficient,... the woofer would tend to be 10-12", the midrange 4-5" and the tweeter 1". If you add constraints such as placing value on a small size then one might accept the extra cost of 2 x 8" or even 4 x 6.5" drivers. Alternatively one might add costs in order to get a longer than usual linear displacement via motional feedback or more careful motor design. Another option, and a common one, is simply to surrender technical performance and use inadequately sized drivers.
??? The most common configuration for a top of the range or near top of the range commercial home speaker for the last few decades has been something like a 2 x 8" woofers, 4-5" midrange and 1" tweeter in a tower. It is pretty much the optimum design for a high fidelity home speaker today because of the laws of physics, economics plus a touch of what is visually acceptable in a living space. It might be a boring rather than interesting configuration for DIY hobbyists but it is the dominant one for those with an interest in high fidelity sound in the home.
Both of your comments are very helpful and ... oddly reassuring. With regards to your second comment, I meant that there had been little to no reference to this type of solution on this thread. I suppose that's inevitable, since the thread is addressed to Troels' designs, where there are very few examples, indeed, of 2x8 dual woofer based 3 ways. Huh! Perhaps I should have asked for opinions on a Rick Craig shortlist, where (if we include the archives) there is quite a preponderance of these designs.
For my part: I think it is rather pointless to spend loads of money on some elaborate design when you already know you're placing speakers close to the front wall and you are not into treatment of room acoustics by means of passive and possibly active (multisub) measures.
Rather buy/build some 'well enough' design and spend the rest on good food, wine or whisky. Because excessively expensive speakers in a mediocre acoustic setting is like driving Ferrari to move your family and the dog around.
Halcyon ~ Markaudio + SB Acoustics Full Range with Bass Assist Tower - Pair: Madisound Speaker Components
Speaker Design Works
Speaker Design Works has numerous designs in different configurations, take a look.
Speaker Design Works
Speaker Design Works has numerous designs in different configurations, take a look.
After a few months of construction using 25mm MDF (compensated dimension cabinet), my SBA761 are now in white primer ready for sanding and top coat. They look quite good in white. Unfortunately, I've decided that my room and equipment is not a good match. Poor choice on my part. They are only 30cm from the wall firing across 3.6 m room by 7m long. Originally, I planned them to go the other way firing along the room, but I can't do that now. My power amp is a very big chap both in weight (28kg) and sound, Alchemist Forseti Signature version, beast. I mainly play rock, but also electronic, EDM, and easy listening. Sounds great with Joni Mitchell, S&G, Lionel Ritchie, Jazz, etc. When I play EDM and experimental electronic music, the bass overpowers the sound.
So, sadly, they need to find a new home after all that work.
So, sadly, they need to find a new home after all that work.
The majority of the designs is supposed to be placed away from the walls, I use to have the same problem with any speaker I tried (so much bass, choking the overall experience) .
I suggest you could try and convert the 2.5 way to a three way, since the woofer is at a separate volume. Seal the mw16p and work the crossover, the satori drivers are easy to work with and you will get rewarding results.
Hi everybody
I am planning to built new speakers and was choosing between two TG projects: SBA 741 + bas-module or Ekta mk2 + 10" subwoofer. When I found this thread, I changed my mind and now got very interested with Mona Kea. I have some questions about it , tried to PM , but I am still under moderation - I am new here . Thanks
I am planning to built new speakers and was choosing between two TG projects: SBA 741 + bas-module or Ekta mk2 + 10" subwoofer. When I found this thread, I changed my mind and now got very interested with Mona Kea. I have some questions about it , tried to PM , but I am still under moderation - I am new here . Thanks