Why do all of the tweeters for the DIY market suck?

Audio Playback
1

I just want a good tweeter with high efficiency, high power handling, a high first breakup mode, and a flat face plate for easy loading into a waveguide.

Why doesn’t any manufacturer make such a product at a reasonable price?

Almost every tweeter I find has some stupid faceplate and a low Fs and a low sensitivity. They talk about a low Fs like it’s a good thing too! I’m not crossing the tweeter at 1000Hz like a retard and I don’t give a fuck about your super low 600Hz Fs with 86dB sensitivity. WTF is this garbage?

I just want one good tweeter with none of this stupid bullshit and I can’t find a single one!

2

well what is a reasonable price ?

the tweeter you described would be something like this ( yes i understand this isn’t the type of tweeter you’re looking for, this is to make a point ):

frankly at $420 a piece it’s a bargain when you consider the engineering and performance:

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i actually think JBL replacement drivers are an untapped gold mine for DIY audio because even though they aren’t officially sold like say B&C, RCF, Beyma, Eighteen Sound etc. you can still buy them and i think the value is sometimes amazing. for example a somewhat comparable dual diaphragm compression driver from the Europeans would cost almost double. Of course Europeans have a slightly different approach in that they use a 2-way design with crossover whereas JBL dual diaphragm driver runs both diaphragms largely in parallel but they are never the less not identical - one is tuned more for lower end and one for higher end, but their frequency spectrums overlap unlike the European alternatives that use high slope crossovers. So actually it’s a different operating principle but the level of engineering and manufacturing involved is similar and the JBL replacement is significantly cheaper - an amazing value IMO. it should wipe the floor with any $5,000 ribbon up to about 10 khz which is all that really matters.

this is the tweeter i would use myself for a nice dual 15" 3-Way clone of JBL VTX F35

my point here is that $400 is really about as cheap as such a driver can be manufactured. this driver is not marketed for sale. this is just a replacement part. the actual F35 that uses this tweeter is $7,000 each, so you’re paying just over 5% of the speaker’s cost for the replacement tweeter - a great value IMO.

one possible reason to stay away from something like this is replacing the diaphragm may be very difficult ( and i’m not sure replacement diaphragms are even available ). i haven’t researched this subject at all. there is enough power handling that unless you make a mistake you will never blow it but mistakes are always possible.

with older style compression tweeters you can relatively easily replace the diaphragm but with these new dual diaphragm drivers i think it might potentially get more complicated … though you can get replacement diaphragms for BMS drivers … which is a German company and JBL actually rebadges some of their tweeters.

BMS tweeters are state of the art just like JBL and Celestion Aperiodic …

of course each of these drivers is unique - they aren’t clones of each other - that is the point - these are the designs driving the industry forward …

3

well because you are looking at dome tweeters and you should be looking at compression drivers.

waveguides really are just half assed horns.

you can engineer a horn to perform like a waveguide but you can’t engineer a waveguide to perform like a horn.

the reason waveguides are used on studio monitors is because it is MUCH CHEAPER to do it that way. with a VTX F35 you’re looking at $400 tweeter in a $400 horn while with a typical studio monitor you’re looking at a $20 tweeter in a $5 waveguide. of course they will tell you that waveguides avoid “horn colorations” or some BS like this but really it’s just about the bottom line.

compression drivers use large horns, large magnets and tight tolerances - all of this is expensive. studio monitors avoid all these costs by using regular dome tweeters in medium size waveguides. then they tell you that they do this because it’s “better”

if you believe that you may as well believe that a bicycle is better than car, which is what Urbanists want us to believe.

4

well for a tweeter FS would be affected by moving mass, suspension compliance and the volume of the rear chamber. obviously higher moving mass in a tweeter is a very bad thing so if they get low FS that way that is definitely whack but i doubt anybody is deliberately adding mass to tweeter domes to lower FS.

more likely they lower FS by increasing rear chamber volume or by using a more compliant suspension, both of which could be a good thing.

more compliant suspension would likely result in lower distortion because suspension nonlinearity is the second largest distortion mechanism in a driver after motor nonlinearity. we minimize motor nonlinearity effects by staying away from excursion limits and we minimize suspension nonlinearity effects by operating above frequencies where suspension has an effect, which means that if low FS was achieved by a more compliant suspension it may mean lower distortion.

if low FS was achieved by larger chamber volume it may also be a good thing because it shifts impedance spike further from crossover region and if you’re doing a passive crossover that may make your life easier. on other hand if you cross at the actual FS you could use it to your advantage and get away with a simpler crossover by using natural rolloff of the tweeter essentially as a part of your crossover.

so it really depends.

86db tweeter is definitely not great, but 600 FS is not necessarily a bad thing. if you want to cross at 2.4 khz then it would probably be easiest to do with a tweeter with 2.4 khz FS but it would be easier to do with a 600 FS than 1200 FS … basically either FS should match your crossover frequency exactly or be as far away from it as possible …

and if FS is to match your crossover then the high FS should come from low chamber volume and NOT from stiff suspension. because stiff suspension will create potentially audible distortion.

5

you won’t find a flat faceplate on a good tweeter most likely but you can remove the faceplate on most tweeters and mount the waveguide that way.

some small tweeters are already sold without a faceplate but they are rarely good, though they are almost always well priced. ( like $10 )

that said none of these drivers regardless of price are high performance. all high performance drivers are compression drivers. because once you understand the benefits of compression horn drivers the only reason not to take advantage of those benefits is to cut costs.

so a $1,000 regular dome tweeter is still ultimately cheaper than a $100 compression driver. you can never get more than what you pay for but you can always get less. this is Dissident’s law of thermodynamics if you will. you can’t get something for nothing - there are no miracles. but you can always get scammed.

any dome tweeter over $50 is basically a scam.

dome tweeters should be about $5-$30. compression tweeters about $50 to $300. if you need more performance than a $500 driver can deliver you need to be looking at arrays.

ribbons are somewhere between domes and compression drivers. i mean we’re looking at about 88 db for domes, about 98 db for ribbons and about 108 db for compression drivers …

furthermore compression drivers and arrays also offer best directivity control …

ribbons arguably offer the worst, which is why they are also least popular …

basically:

domes = cheap ( regardless of price )
ribbons = exotic ( cost more to make than performance they deliver )
compression = high performance at high price
compression driver arrays = state of the art and beyond what most can either afford or engineer

6

i wouldn’t worry too much about this unless you’re talking about a large titanium compression dome.

7

DIY market is too small to justify ANY amount of R&D going into it.

90% of tech in audio is developed for prosound and trickles down from there, because prosound is where the most stringent performance requirements are.

prosound to audio is like military to most other tech.

just like GPS, Internet and so on were created by the military and later trickled down to the consumer …

a compression driver to a dome tweeter is like a jet engine to a piston engine. it’s on another level of both price and performance.

yes you can make a very expensive piston engine but no matter how much it costs it will never perform like a jet engine.

it will never perform like this:

you can’t buy an F22 but you can buy a compression driver and i personally wouldn’t buy anything else …

not even a Ribbon …

you can even create a line source out of compression drivers using V-DOSC acoustical lens:

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essentially there is practically no application in which compression drivers can’t outperform everything else.

and that’s why you will always struggle to find a good dome because anybody who understands performance will not bother with anything other than compression drivers.

you’re basically asking - why can’t i find a car that will allow me to drive from NY to LA in 6 hours ? the answer is because that car is called a plane.

it’s called a compression driver.

even if it was possible to build such a car it would be a complete waste because you would be solving a problem that has already been solved.

8

here is an affordable driver you can consider, it’s about $80:

https://www.bmsspeakers.com/index.php-48.html?id=4526nd

you could build something like 3-way out of it using a 6" midrange and 15" woofer.

9

I want a tweeter, not a compression driver. There are tweeters that sort of fit the bill, but they are $500+. I don’t get that. I agree that a good tweeter shouldn’t be that expensive.

Compression drivers have higher distortion than domes at low levels. Yeah they can play louder overall, but they are not what I consider high fidelity devices. Nothing I’ve heard from JBL compares to a good tweeter. They also have to be loaded into horns, and I don’t want that level of directivity control.

10

i have seen measurements of Celestion Aperiodic “tweeter” ( it has a 7 inch diameter titanium diaphragm and 5" voice coil ) showing distortion 100 times lower than threshold of audibility, and that was measured at 100 decibel level. distortion will be even lower at normal listening levels.

what you call “distortion” is probably “harshness” from titanium dome breakup … that is to say spikes in frequency response, rather than frequencies added to original signal … technically both are “distortion” but when i use the word i refer to nonlinear distortion whereas linear distortion is simply bad frequency response …

titanium domes are a somewhat obsolete type of compression driver … the new technology is polymer ring diaphragm which is far smoother sounding …

look into Faital Pro and BMS drivers …

JBL uses old style compression drivers in most products and very cheap compression drivers in entry level products - only VTX series and big arrays use good modern compression driver designs …

11

the reason many compression drivers out there sound harsh isn’t because this is inherent to compression driver design but simply because for their intended purpose ( cutting through the noise in a club ) it is considered almost a benefit - that extra bit of “bite” to the sound …

but i think this is changing. people are demanding smoother sound, which is why we’re switching from titanium domes to polymer rings.

even if you look at music it used to be all about hi-hat to spice things up but that has been phased out - people are looking for a smoother sound now.

12

they shouldn’t exist at all as far as i am concerned.

anybody making dome tweeters out of beryllium is wasting their money.

a compression driver made out of regular plastic will still outperform it.

having flat response to 30 khz isn’t really a meaningful benefit.

you need to be flat to about 6 khz with extension to 12 khz … bonus points if there is still some output at 16 khz … a compression driver can be engineered for this …

those $500 tweeters you speak of are made for bragging rights and “oscilloscope like listening” … they are made to please those who specifically listen for flaws rather than simply enjoy the music …

it’s like those car reviewers who crawl on their knees to test whether “soft touch materials” are used in the lower part of a car door - as if it makes any difference in real life.

yes sure you can test speakers using a special track of nothing but cymbals and A/B test it against a genelec with a 19mm metal dome tweeter to determine which speaker is more “accurate” but reality is if you look at any famous microphone - most of them don’t even extend to 20 khz …

in other words the music you listen to is already “not accurate” to the original sound, and that assumes the original was acoustic to begin with and not synthesized.

forget about accuracy and flat response to 20 khz and you will be much happier.

that doesn’t mean that there aren’t harsh sounding compression drivers. probably most if not all older large titanium compression drivers are fairly horrific sounding. but technology is advancing when it comes to compression drivers - which is something that can’t necessarily be said of dome tweeters.

dome tweeters today are pretty much the same as 50 years ago. whereas compression drivers today are superior to ones from even 10 years ago.

dome tweeters are about as relevant to performance as passive crossovers.

the future of performance is all DSP, all compression.

13

if you want affordable but good dome tweeters like ones used by Genelec in their monitors maybe look at SEAS ( Scandinavian Electro Acoustical Systems ) - they have fairly decent tweeters for about $30.

i think i used them in a car once with good results though it was about 20 years ago so i may be getting confused …

i think they were magnesium alloy … i think my Mackie monitors also used magnesium alloy domes … quite possibly the same ones. they sounded very clean and accurate. the problem with the mackies was the 8" woofer couldn’t quite reach up to the crossover causing a muddy sound due to lack of midrange, but the tweeter itself was good. it was waveguide loaded as well in the Mackie though obviously Mackie provided the waveguide.

for nearfield listening perhaps a 3-way using 12" woofer, 5" midrange and 1" magnesium dome could be a good analytical monitor. but nearfield listening is not enjoyable.

to enjoy music you must dance. and that by definition involves at least mid-field and thus larger speakers with 15" woofers and 18" or 21" subs.

dome tweeters = analytical near field listening not to enjoy but to tell people on the internet how accurate your speakers are

compression = actually enjoying LOUD music by jumping up and down on the ceiling not giving a shit whether it is accurate or not

14

Can you post these measurements? I don’t know of a lot of direct measurements of compression drivers that can be compared to the same measurements of domes. The only measurements are for speakers with compression drivers vs. speakers with domes. Also, measurements for compression drivers are always in some kind of horn, and the horn has a lot of influence on the measurements. It’s difficult to assess how they will behave in other horns.

15

couldn’t find the particular page on DiyAudio where i saw it but i can use another driver as example.

Celestion Aperiodic was simply an example of a high-end compression driver using the latest technology.

we can use another high-end compression driver using the latest technology instead, the BMS 4595HE

https://www.bmsspeakers.com/index.php-67.html?id=bms_4595he00

why ? because they actually post distortion measurements in the spec sheet:

this is a coaxial driver and they have two sets of distortion measurements - using an active and a passive crossover. i will post the one using passive crossover as it’s less confusing.

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let’s look at 3rd harmonic - it only shows up on the graph at 7 khz and above. but a 3rd harmonic of 7 khz is at 21 khz so inaudible completely …

second harmonic on the graph is significant from 3 khz up, so from 6 khz up in reality since 3 khz is the fundamental … at this point ( 6 khz ) it’s nearly 20 db down on the graph, but the graph itself is raised 10db so it’s actually 30db down from fundamental …

distortion audibility is frequency dependent, but even though it’s more audible in upper midrange and treble i believe the threshold of audibility there is about 1% THD which corresponds to -40 db.

so at -30 db actually the measured distortion for this BMS would be audible …

but notice the measurement level - it is 1 watt or 110 decibel output. by comparison a smoke alarm is bout 90 decibels. so we’re talking 20 decibels louder than a smoke alarm here and a smoke alarm is already unbearably loud.

at a level you actually listen to music at distortion will be far lower and most likely inaudible. and you still maintain basically unlimited headroom for cymbal crashes and so on with 110db / watt efficiency and 1,000 watt peak power handling …

of course at that 1,000 watt peak distortion will likely be around 100% or so but distortion should be inaudible in any realistic home listening scenario …

as i said unfortunately i couldn’t find the measurement that guy did at only 100db where distortion was crazy low for the Aperiodic driver - obviously these are prosound drivers and they don’t typically get tested at such low levels as are used at home …

maybe ask around on DiyAudio for any measurements like that - i am sure there are people there who have done it.

also note you can COMFORTABLY cross this BMS at 1 khz with a large enough horn. this is because at 1 khz and 110 db distortion is 40 db down. so basically you cross it straight to a 15" woofer at 1 khz and you have a state of the art sound system.

B&C has a similar driver and their demo system was an MTM with two 15" woofers.

An ultra high end driver like this is intended for stand alone point source use such as in a cinema application. Rock Concerts will instead use arrays of simpler drivers ( without crossovers ).

16

if you want a rule of thumb intuitive explanation - the more pistonically moving surface area you have the lower your distortion will be for any given output level.

small drivers have high distortion because surface area is low.

large drivers sound harsh because they aren’t moving as a piston and have a lot of breakup.

a ring radiator like the ones i posted here is really like dividing by zero - you get large surface area AND you avoid breakup because all of the diaphragm material is close enough to the voice coil to move together as one at frequencies that matter … additionally because diaphragm is polymer and not titanium the breakup is better controlled …

why don’t all speakers use this technology then ? well because this driver requires a phase plug and a horn and those cost money. but for that money you get higher output for any given level distortion or conversely lower distortion for any given level of output.

17

i mean … a 1" beryllium dome will probably sound cleaner at 70 decibels than a 3.5" polymer ring will …

but the range of applications for such a tweeter would be so limited that the to make up for the cost of R&D the cost would have to be extremely high …

whereas drivers like the one i mentioned are more expensive to manufacture but the costs of Research and Development are more efficiently amortized because there is a sizeable market for these products in prosound … so as a result you end up getting more for less compared to a DIY oriented driver of same caliber …

18

it’s a balancing act. you have:

1 - manufacturing costs ( paying the workers in a factory )
2 - tooling costs ( buying the robots, creating the molds etc. )
3 - R&D ( research and development ) costs ( designing and testing the driver )
4 - size of the market ( how much money is there to be had if the product sells )

i am not even going to talk about marketing costs here …

you’re only looking at ( 1 - manufacturing costs ) and you’re like - why doesn’t the product i want exist at the price i want to pay ?

well because the size of the market ( 4 ) for the product you’re looking for can’t bear the costs of ( 2 and 3 ).

with prosound by the way marketing is basically eliminated because all the pros talk to each other and products are advertised by word of mouth.

19

I just wish there were a few good tweeters on the market that don’t cost a fortune and are actually well designed. They don’t need to be as loud as compression drivers, but they can be a lot better than the garbage that it out there. A tweeter should be able to hit 115dB above 2000Hz without blowing up, but very few of them can do that and the ones that can are overpriced. The problem is that they are designed for audiophile bullshit and not to be good.

20

Pro audio drivers run circles run circles around the garbage available in the DIY and audiophile market. When I look at the specs and measurements of woofers from Scanspeak and companies like that I can’t help but laugh at how bad they are compared to proper drivers from Italy.

Unfortunately these companies don’t make tweeters. I prefer tweeters over compression drivers for applications that don’t require crazy output, but the only tweeters you can buy come from amateurs who don’t know shit about designing drivers.