Remember for every +3db you need to double the amplifier power.
So when choosing a speaker, definitely take in account the sensitivity,
With +90db speakers you'll have much more compatible amplifiers,
the amplifier doesn't need to play loud (loud=high voltage swing),
that means less amplifier distortion.
My speakers are 93db and are quite happy with 25watt (preferable in class A
)
So when choosing a speaker, definitely take in account the sensitivity,
With +90db speakers you'll have much more compatible amplifiers,
the amplifier doesn't need to play loud (loud=high voltage swing),
that means less amplifier distortion.
My speakers are 93db and are quite happy with 25watt (preferable in class A
)
Last edited:
Most, ironically, Your rationale above is why I began looking at Troels designs: with the idea that sensitive drivers would most likely have me listening (at moderate levels), in class A with my current amp. However, he also implied that the trade offs for sensitivity e.g size of drivers and other design considerations, were kind of inappropriate for solid state users like myself. So here I am!
Last edited:
Then there is something seriously wrong with what is called "gain structure" of your set up.
Well you could check yourself what it means to have good gain structure.
Adviced reading:
What is Gain Structure?
Adviced reading:
What is Gain Structure?
Last edited:
I had the tweeter at €400, the upper midrange at roughly €150 and the midwoofer at €370.
Not sure I understand. The expected performance in your room of the various speakers you have considered is irrelevant?
You have settled on a design for good reasons as you see and value things. In this thread and elsewhere there is conflict between the scientific/technical view and more audiophile/subjective ones of various flavours. In you case a lack of relevant technical knowledge requires you to look for guidance from others and choose who/what to believe without really being sure what is or is not correct technically. Plus of course you will value a range of other things apart from technical performance.
In the light of this I was simply trying to understand your reasoning for ending up where you are. You have supplied some of this in your reply so thanks.
There is a physical relation between efficiency, size and low-cutoff. In essence a small speaker with high efficiency will have lousy low frequency reproduction.So your reasoning is already good
You can find plenty of +90db designs that still have a reasonable size.
High sensitive speakers sound more dynamic, live recording will sound more like live
Thanks for the Link daanve I guess the modular nature of my pre might help. I'll read the link before I guess any further.
Last edited:
It is difficult to make a comparison because there was quite a bit of time between the speakers. In addition, the rooms were not comparable.
I would attest the MK a better 3-D imaging and more clarity in the sound. Despite the many drivers, it plays like a single piece.
The DTQWT was also good in all areas, but it didn't catch me that much and I would always prefer the MK. So I think the MK would definitely be a good solution for you.
A 2.5" driver is too small to handle the lower midrange frequencies and is conventionally used as an upper midrange in 4 ways. SBAcoustics refer to theirs as a filler driver which is slightly different.
A 6.5" driver is too small to be a woofer in main speakers in a normal room. Woofers tend to be 8" or above in size with 10-12" being around the minimum size for clean low frequency transients at standard levels in a non-booming medium sized room. Multiple drivers is a way for smaller drivers to get adequate volume displacement and this is reflected in the modern trend to move away 1 x 12" woofers in a wide cabinet to 2 x 8" woofers in a narrow tower cabinet. 2 x 6.5" is marginal in terms of cone area but your extremely expensive midwoofers have a larger than normal displacement and so they might be adequate. Not optimum but possibly adequate.
Of course if you used woofer/s then you would also need to use a midrange driver in a 3 way or a lower midrange and upper midrange drivers in a 4 way. The design you have chosen has the disadvantage of being unbalanced in having an overly wide passband for the midwoofer and an overly small passband for the upper midrange (assuming the driver is used as intended) with no balancing advantage that I can see (involves a degree of speculation given the absence of a firm design) with nothing to justify such a high price in terms of technical performance. To the cynical it might look like picking the currently most fashionable expensive drivers and chucking them together in a box rather than designing a speaker and picking drivers that meet the requirements. I think this point may have been made by others earlier in the thread.
Don't tell me about that relation, it's the most frustrating in speaker design, there are no free lunches.
With reasonable size I mean about 100 liter, that volume can give good sensitivity and good bass
Thx for the answer. I think i will go to the MK, all the more Monacor speakers are cheaper and easy to find in here in France. But when i start buidling new speaker, i take existing model, don't try to change/adapt crossover or speakers, and i take a lonnnnng time to adpat the box to my taste, knowing that some changes are not possible without a change in crossover. So it take a long time to finish the build. So, while thinking/buiding the MK, i think i will try the OBL15 from Troels : i already have the tweeter and mid from the dtqwt and a large part of the crossover, i just have to find the woofers, and the basic buidling - without finish, just to try - is very easy. Speakers are also a matter of taste, and who knows, perhaps i'll fall in love of OB.
"The design you have chosen has the disadvantage of being unbalanced in having an overly wide passband for the midwoofer and an overly small passband for the upper midrange."
Yes, I believe I already have some sort of understanding of these particular characteristics. So, for a non techno like me, can you briefly explain why you perceive these characteristics as excessive "overly" and why they suggest an unbalanced design?
Allegedly, the Purifi's drivers are less prone to the potential compromise to the mid range that can sometimes be the case with larger than e.g. 4" mid drivers and I'm guessing that's a part of their particular suitability for 2 way designs . I'm not sure if that's also relevant to your comment above. I should add that with my limited knowledge, I've referred to the design as a 3 way, given the line up. It's clearly not a 2 way!
Last edited:
I wouldn't say that a 6.5 "driver is too small for bass in normal living rooms. That always depends on the driver and the Purifi can do a lot there.
And a lot of 6.5 "drivers are absolutely 2-way suitable, so the combination with the midrange dome is quite possible.
For example, we already heard very loud with the Lewis in Alex's listening room (normal conversations were no longer possible) without noticeable loss of sound. And that's a simple 2-way design with one 6.5 "driver.
Pegelfeste lineare TQWT mit 30Hz Tiefgang und gutem Abstrahlverhalten - gazza-diy-audio.de
But I also think the project is very expensive. Of course the drivers are all very good, but then everything else has to be perfect to really have an advantage. And when I look at the cabinets and measurements at Selah, I don't know whether that is really the case.
Sounds like a good plan. OB also has its charm, but you also have to be able to position it correctly.
My opinion is that you should always build a speaker by a designer true to the original. If you know the result, you can of course play with it a little longer. However, the basis must always be the original, otherwise you cannot evaluate the design.
And a lot of 6.5 "drivers are absolutely 2-way suitable, so the combination with the midrange dome is quite possible.
For example, we already heard very loud with the Lewis in Alex's listening room (normal conversations were no longer possible) without noticeable loss of sound. And that's a simple 2-way design with one 6.5 "driver.
Pegelfeste lineare TQWT mit 30Hz Tiefgang und gutem Abstrahlverhalten - gazza-diy-audio.de
But I also think the project is very expensive. Of course the drivers are all very good, but then everything else has to be perfect to really have an advantage. And when I look at the cabinets and measurements at Selah, I don't know whether that is really the case.
Sounds like a good plan. OB also has its charm, but you also have to be able to position it correctly.
My opinion is that you should always build a speaker by a designer true to the original. If you know the result, you can of course play with it a little longer. However, the basis must always be the original, otherwise you cannot evaluate the design.
A driver needs to be physically large to shift enough air at low frequencies while at the same time physically small to avoid/minimise cone resonance issues at high frequencies. There are of course other considerations and one or two things that can be done to extend a passband at either end but it is broadly why a driver has a comfortable passband of roughly a decade.
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.
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.)
They look like well designed midwoofers which are sized for use in 2 ways and 4 ways but are too small to be a woofer and too large to be a midrange in a conventional 3 way. The price would seem to place them more in the boutique audiophile category rather than serious high performance category. The most appropriate use I can see for them would be to cover the 100-1kHz range in a cardioid design. The large amount of sound cancellation in such designs significantly reduces efficiency and raises distortion which the long stoke design would help counter.