Hi ! looking for information about drivers i found this thread
https://www.diyaudio.com/community/threads/fs-magico-7-4-ohm-4-pcs.376772/
being a giant killers hunter for dna ... one comment hit me deeply this one
https://www.diyaudio.com/community/threads/fs-magico-7-4-ohm-4-pcs.376772/post-6800525
to cut to the chase i would love to know how do you select a driver for your project
I am mostly interested in woofer from 8" to 6"
Thank you very much and kind regards gino
https://www.diyaudio.com/community/threads/fs-magico-7-4-ohm-4-pcs.376772/
being a giant killers hunter for dna ... one comment hit me deeply this one
https://www.diyaudio.com/community/threads/fs-magico-7-4-ohm-4-pcs.376772/post-6800525
to cut to the chase i would love to know how do you select a driver for your project
I am mostly interested in woofer from 8" to 6"
Thank you very much and kind regards gino
last one i promise on this topic I recap the story
A woofer is on sale for 2000USD
One person's comment is that a 80USD alternative could sound better
25 times less the cost
Does this fact not impress you ?
All my life i have been looking for the best Q/P ratio products (i am not rich of course)
I can very well understand that a complete loudspeaker involves other materials, men labour cost etc. things that can drive the final price very up
But a driver is a driver ... is a component
There must be a methodology to spot a better component at a lower cost
I propose distortion ... the lower the distortion at a fixed SPL the better the driver
Surprisingly distortion performance are very rarely present in the drivers datasheets
But imho not because they are not important Exactly for the contrary
Because it would make too easy to spot the better ones from the less better ones
A woofer is on sale for 2000USD
One person's comment is that a 80USD alternative could sound better
25 times less the cost
Does this fact not impress you ?
All my life i have been looking for the best Q/P ratio products (i am not rich of course)
I can very well understand that a complete loudspeaker involves other materials, men labour cost etc. things that can drive the final price very up
But a driver is a driver ... is a component
There must be a methodology to spot a better component at a lower cost
I propose distortion ... the lower the distortion at a fixed SPL the better the driver
Surprisingly distortion performance are very rarely present in the drivers datasheets
But imho not because they are not important Exactly for the contrary
Because it would make too easy to spot the better ones from the less better ones
There is no driver on earth that's worth $2000 to me. In fact, I'd have second thoughts about anything over $100 or so. Obviously people with more resources would view things differently. Mostly I look at the response curve and T/S parameters. It has to work in the design, so the parameters have to be suitable. Then I want to see a response curve that's reasonably smooth, not requiring any electronic magic to flatten it out, and rolloffs that make a crossover practical when combined with the rolloffs of some other potential driver.
Hi ! thank you very much for accepting my provocation and for the very valuable advice
I agree completely with what you say
I am trying to figure out what makes a driver better than another for similar basic electric parameters like FR and impedance
what in my mind sets apart the very good drivers is a very low distortion also at quite high SPLs And strangely enough distortion figures are almost never present in datasheet
Am i looking at the wrong thing ?
I know some people using high end speakers with small drivers in very big room replacing these speakers even with PA speakers because they struggle to fill the room with sound
If i had a big room i would look at those products
Instead my interest stops at 8" I am willing to give up with the very low bass A good 8" woofer can provide a very decent bass in a small room
Maybe even a 7"
So i was looking and i found the discussion about 7" woofers much differently priced
And i am now looking at the SB Acoustic catalogue
You can also look at Xmax and design details like flux modulation rings (or some similar phrase). I haven't priced them lately but I've had good results with Peerless, maybe something like https://products.peerless-audio.com/transducer/78 depending on the box design you want. They're about $62 but presently out of stock. Seems to be a common problem.
I've been known to take a chance with surplus like surplussales.com Surplus is pure luck- it just depends on what they have at the time. Given the prices, I'd also be looking at Alibaba and such. I do notice that some high quality brands I used to like no longer supply individual drivers. I haven't bought new drivers in a long time, so the landscape has changed a lot!
I've been known to take a chance with surplus like surplussales.com Surplus is pure luck- it just depends on what they have at the time. Given the prices, I'd also be looking at Alibaba and such. I do notice that some high quality brands I used to like no longer supply individual drivers. I haven't bought new drivers in a long time, so the landscape has changed a lot!
Hi thanks a lot again Strangely the good and cheap things run out of stock pretty quickly and the shelves are full of even good but very expensive parts
Its the same with audio shops They are trying to sell few very very expensive items instead of many cheap ones A old friend of mine has a shop
He contacted me to offer a nice pair of bookshelf speakers for ONLY 20keuro I am sure they sound very good but ....
i see I have a problem If i do not know the specifications of driver i am quite lost A better bet could be to look at vintage models
For instance north european brands used to use good quality parts especially dome mids and tweeters I have already some to try out from Grundig Braun and Telefunken Woofers are my nightmare And hearing that a 80$ component can beat a 2000$ gets me dizzy literally Like what the .... ???
I would like to add the one brands that i truly love is Revel Some years ago i found a rumor that the very nice concave Al woofers (that i dream of) used in their top models were sourced from China where they costed little ad 50$ !!! these are my dream drivers I have never known if this was just a fake news or what I drool about those drivers
https://www.avhorn.co.za/wp-content/uploads/2021/04/revel-ultima-salon-1s-f-c069e163.jpg
the perfect drivers to me I love concave woofers and mid deeply The perfect shape to me I really do not understand why this diaphragm shape is not more popular I would put a law that oblige to use that shape only Even for tweeter Because i like coherence always If a concept is sound is sound for any application And i also like simmetry
See this writeup about drivers: http://www.nutshellhifi.com/library/speaker-design2.html
I'm a piano, organ, bassoon & cymbal (marching band) player, so I place importance on both accurate lowest octave, also the top octaves like on the piano or bells or cymbals. I was playing 7 octaves of piano age 11 (lecuona malaguena). I don't need rock concert levels of bass, but the notes need to be there to 26 hz. I've never heard a bookshelf speaker that impressed me; perhaps because the store was demonstrating with Simon & Garfunkel which has no bass. Now all the stores that demonstrated hifi have gone bankrupt. So I restrict 6.5" or 8" woofers to television viewing. Actually my TV room speakers have visaton bg17-8 6.5" full rangers in a vented box.
I went looking for Voice of the Theater copies (that I heard live in 1966) in 2004, after I saw something similar pictured on craigslist. I auditioned a 2 way with 12" woofer and a 2 way with 15" woofer on Beethoven Appassionata at a musician's store, and ended up buying the 15" model. I listen at 1 watt in a 14'x10'x33' room, but find the effortless bass and accurate highs of the SP2-XT still very satisfying. Evan at 700 w that 1505-8KADT woofer only has 0.9 mm excursion (xmax). So maybe why the 500-1800 hz (SP2(2004)) from them is so undistorted.
The SP2-XT were stolen 2020, having pawn shop value. So I am trying to build copies that are really ugly and won't be carried off when I am out of town. I want high sensitivity(>98 db 1w1m) so I don't need a bigger amp than 60 w/ch. Passive crossover choice (bi amps waste electricity) requires smooth frequency response that doesn't take too many crossover components to smooth out. I'm experimenting with eminence Deltapro-15a that have a slight peak 1000-1500 hz that will have to be tamped down in a 2 way that crosses at 1200 hz. But they can dig down to 54 hz - 3db in a vented box. I paid $187 each for them.
I'm a piano, organ, bassoon & cymbal (marching band) player, so I place importance on both accurate lowest octave, also the top octaves like on the piano or bells or cymbals. I was playing 7 octaves of piano age 11 (lecuona malaguena). I don't need rock concert levels of bass, but the notes need to be there to 26 hz. I've never heard a bookshelf speaker that impressed me; perhaps because the store was demonstrating with Simon & Garfunkel which has no bass. Now all the stores that demonstrated hifi have gone bankrupt. So I restrict 6.5" or 8" woofers to television viewing. Actually my TV room speakers have visaton bg17-8 6.5" full rangers in a vented box.
I went looking for Voice of the Theater copies (that I heard live in 1966) in 2004, after I saw something similar pictured on craigslist. I auditioned a 2 way with 12" woofer and a 2 way with 15" woofer on Beethoven Appassionata at a musician's store, and ended up buying the 15" model. I listen at 1 watt in a 14'x10'x33' room, but find the effortless bass and accurate highs of the SP2-XT still very satisfying. Evan at 700 w that 1505-8KADT woofer only has 0.9 mm excursion (xmax). So maybe why the 500-1800 hz (SP2(2004)) from them is so undistorted.
The SP2-XT were stolen 2020, having pawn shop value. So I am trying to build copies that are really ugly and won't be carried off when I am out of town. I want high sensitivity(>98 db 1w1m) so I don't need a bigger amp than 60 w/ch. Passive crossover choice (bi amps waste electricity) requires smooth frequency response that doesn't take too many crossover components to smooth out. I'm experimenting with eminence Deltapro-15a that have a slight peak 1000-1500 hz that will have to be tamped down in a 2 way that crosses at 1200 hz. But they can dig down to 54 hz - 3db in a vented box. I paid $187 each for them.
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Hi thanks for the valuable advice I dont have enough space for a speaker of the VOT size ... unfortunately 😢
at max a big bookshelf one
After many years of trying different speakers I found Fane to have some of the best performing.
I currently use a pair of Fane 12-250TC's in a sealed box.
I currently use a pair of Fane 12-250TC's in a sealed box.
Those Fane speakers are not bad at all. Highly efficient and decent bass.
The reason distortion numbers are not listed is because speakers are terrible when it comes to numbers! An amp might have .1% THD and a speaker will be 50 times that much in the lower frequencies. Would you buy anything that said 8% distortion? In the mids and highs it gets much better(lower).
The reason distortion numbers are not listed is because speakers are terrible when it comes to numbers! An amp might have .1% THD and a speaker will be 50 times that much in the lower frequencies. Would you buy anything that said 8% distortion? In the mids and highs it gets much better(lower).
hi very interesting thank you very much indeed
did you select it on the basis of measurements or listening tests?
i am believer of measurements but i concede that some aspects like sound tonality are difficult to measure with instruments
if i had to list my favourite measurements i would say FR CSD and probably above all others distortion measurements
distortion is the worst thing that can happen to a signal
like a plastic surgery with bad results
true to the source as much as possible
hi thank you for the very kind and valuable advice
finally someone who talks about distortion
every time i open a pdf datasheet i feel sad
almost never there are specs mentioning distortion
i am on phone but i promise to attach a graph that saying just half of the story actually says it all
and i am talking of a driver that can be found in tenth of thousands USD speakers
where the very best should be used
“Low distortion” is the norm for many “pro” type drivers when used at home stereo volume levels. This is one of the reasons some people prefer them, even if the frequency response is less flat. If one is impressed by those Fanes they might try something more modern from say, B&C. They will maintain that low distortion out to higher SPL levels. Their $200-300 price class drivers are pretty damn good - you don’t even need to break the bank with their top models if you’re not trying to get rave levels.
Even lowly Eminence Kappa15LFs will give me nightclub levels at low distortion in my 18x24 wood shop. Levels my Scan-speak loaded system can’t even touch, let alone have less than 20% distortion (and blown ribbon tweeters).
Even lowly Eminence Kappa15LFs will give me nightclub levels at low distortion in my 18x24 wood shop. Levels my Scan-speak loaded system can’t even touch, let alone have less than 20% distortion (and blown ribbon tweeters).
hi very very interesting thank you very much
if i understand well you correlate pleasant sound performance and low distortion?
this is what i meant with my initial question
i tend to think the same and i get surprised anytime i look at a driver datasheet and I don't find ANY useful and reliable information about its distortion
however no audiophile seems to care about distortion these days
they care more about the look
The 1505-8KADT woofer I was puffing in post 7 comes with a distortion chart as packaged in the SP2(2004) speaker. My ears tell me it has the best simulation of a Steinway grand wood piano I have heard in this flyover town. See attached HD chart. I listen at less than 1% rated power, 5 w, except during loud peaks, 60 W.
The current SP2 model has doubled the rated power over the 2004 model with the same drivers, and deleted the HD spec chart.
Attachments
Hi!
I make spreadsheets (or Word Tables) with the driver characteristics across the top, and the driver candidates down the left side. And then I fill in all the cells. I attach the header of my spreadsheet. Sorry, I work for other people, and I can't reveal what I am working on right now.
Now, all the column headers should make sense, except for two.
FORCE Factor is a recognized Thiele-Small parameter.
To be the compliment of (or the converse of, or the contrapositive of, or SOMETHING of) FORCE Factor, I devised the analogous metric LOAD Factor.
The Audio Priesthood responded with, "Howls of Derisive Laughter, Bruce!"
The definition of Load Factor is: gs of Mms per cm2 of Sd
Or, "Grams of Total Moving Mass, divided by Square Centimeters of Driver Area."
In essence, Load Factor is an expression of density; whereas Mms is an expression of mass (or, more colloquially, weight).
Then, my then Design Team colleague Jim Tuomy told me that a new approach to Load invited a new approach to... well... "Get Teslas into it." Not meaning the automobile.
Jim Tuomy was awarded the President's Medal at Bose; he has six patents in electroacoustics; and he uses the same loudspeaker design software as Harbeth does.
So together, we came up with Agility Factor.
The definition of Agility Factor is:
Bxl/LF
Or, "Force Factor divided by Load Factor."
I also hasten to state that our paper, available here:
https://positive-feedback.com/audio...proposed-additions-to-the-thiele-small-canon/
was read by John Atkinson, Technical Editor of Stereophile magazine, and a recipient of one of the AES' highest honors, having been invited to give the Richard Heyser Memorial Lecture. Heyser of course brought unprecedented scientific rigor to loudspeaker measurement.
After laboriously populating my spreadsheet (one project sheet had nearly 40 woofer candidates), I look first at the Agility Factor.
In my current project, the Agility Factors range from 28.41 to 59.46.
I think certain people get threatened by new ideas...
Anyway, the prime contender for the woofer in my next prototype is a custom driver from a very nice and cooperative Danish manufacturer, and the Agility Factor of the driver he is recommending is 22% greater than the Agility Factor of the off-the-shelf but expensive European woofer in my most recent completed prototype.
Please note, there is not an "Iron Linkage" between price and Agility Factor.
An expensive woofer with a very long throw and a heavy cone might have a low Agility Factor. Whether that will be audible, dunno. But with those metrics, one should expect amazing bass.
That said, I am a disciple of Duns Scotus and of course of William of Occam:
The explanation that is easiest to test is the one you should test first. (Most popular versions mangle that.)
Whereas, from a past project, I can tell you that a driver that is too small for your purposes has an amazingly high Agility Factor for the money, the Bold North Audio 4001, with an AF of 58.78, at a price of $78 (well, that is what they charged me).
https://store.miscospeakers.com/4-inch-carbon-fiber-mid-bass-woofer-bna-84071
So, after Agility Factor, I look at bass extension, and sensitivity, and Xmax; and, if available, Recommended Enclosure Volume, and the -3dB in the Recommended Enclosure Volume.
And then, FRANKLY, I look at Snob Appeal and Bragging Rights and Commercial Viability. WHO is going to buy this???
Which is why I get people asking me to work with them.
Anybody can fool himself into thinking that anything more expensive than a $20 Tymphany tweeter is a waste of money.
Best wishes,
john
John we have already gone through that in your earlier Agility Factor thread which does nothing but ride on a few borrowed TS parameters upon which you have cooked up a new woowoo formula, it's a Solution Looking For A Problem which only serves your crave for...
Among loudspeaker designers it's just redundant noise which at best might impress a few audiophools, we can read TS parameters as is and draw some qualitative conclusions a driver may posses from it, TS parameters is after all just bits and pieces in a tool box that doesn't need some fancy sugar coating.
hi thank you very much again
i guess you refer to this one
Peavey 1505-8 KA DT BW
RATING
very impressive indeed I should have said at the beginning that I can't afford big speakers at the moment due to lack of spacemy ideal concept for now is a 2 way satellite above a bass box
but when i have to select drivers i am completely lost
i am very vulnerable to those statements like this 80 usd woofer is better than this other 2000 usd woofer
so i need to know more about drivers selection in general
and woofers selection is my biggest nightmare
if a satellite has to deal with 200 Hz up is not that critical
but from 200 Hz down is very very critical
hi thank you for the very kind and helpful advice
i should have said at the beginning that I am very ignorant about drivers performances
my real question can be summed up like this
Speaking only of cone drivers is IMD a very useful parameter to rank drivers or not?
because if the answer is YES why i can't find it in the data sheet?
what's going on?