Dayton Audio RST28F tweeter | Test and Review

[@TheLevitatingChin]

Some of the finest driver recess cutouts I've seen bar none !

[@dannyverhamme7970]

What a lovely countryside to do the testing!

[@Fish_InChips]

Thank you for your videos. Your reviews are on of the few that I trust. Please continue what you do and keep testing good speakers.

[@alhammons7112]

Sometimes honesty can be a little brutal...I appreciate that!

[@shaunonverwacht9626]

Those terminals are ok if you use push-on crimp receptacles. Often, terminals are not meant for soldering. I made a point of getting 3 sizes of these crimp connectors for the same reason.

[@mikeleahy5283]

Yes

[@ImpulseAudioSpeakers]

Shaun Onverwacht ya a push on terminal would negate that issue. I’ve never had this problem with any other tweeter though. People solder onto terminals like this all the time. Not sure why these would be so sensitive to heat.

[@shaunonverwacht9626]

@@ImpulseAudioSpeakers yes, traditionally they were usually solderable.

[@__-fm5qv]

I actually accidentally melted the terminal right off on my first build. Luckily I managed to solder directly to the voice coil leads they were attached to and it still worked fine. But yeah the plastic gets super soft super quickly.

[@shaunonverwacht9626]

@@__-fm5qv Old school method is to clamp a long nose pliers between the solder joint and the (temperature) sensitive part. Acts like a heat sink.

[@favorit601]

Front plate, mesh, magnet and plastic casing are very similar looking to my Aluminium cone SEAS TAF25, built from 1992-2012.

[@WV591]

speaker terminals are meant for quick connect not soldering iron.also the difference between FS is due to one tweeter was not optimally calibrated voice coil in the magnet gap.

[@Clobercow1]

I have this tweeter, and you're right. It's not easy. It's too big and that 3.5hz diffraction is present no matter what I do with the baffle. It's quite rough to play with. This is more of a small "mid" if you ask me.

[@dansaville3333]

I happened to install some Dayton DC28F-8 tweeters in an old pair of 11.5" wide custom cabinets last night and have the same on-axis dip. Curt Cambell also mentions it on the build pages for his Tritrix design. I think it's something inherit in the design rather than diffraction.

[@ImpulseAudioSpeakers]

Dan Saville there may be something inherent in the tweeter design but there is definitely diffraction at play, which is causing most of the issues. The off axis measurements prove it. If you check out my video about diffraction you will see how this can be improved with a round over.

[@pliedtka]

So we have it - not that bad. Definitely 4k, 2k diffraction peaks and dips - whatever. But most soft domes don't need 'correction' disc in front of the dome, so something is wrong somewhere - the raising freq above 15k perhaps? Terminals - the same problem with other tweeters - now I use something to take that extra heat while soldering. In the past many tweeters used to be 6 ohmers - easier load on amp, very workable with crossovers, efficiency still OK - why manufacturers switched to 4 ohms is a mystery to me - maybe so people think that these are car audio spkrs😋, seriously what's wrong with 8 and 6 ohm impedance. You have to try them in 8x16" baffle, with some 6-7" midwoofer - the peaks and dip will be 1k lower in frequency - maybe it will be more x-o friendly.

[@ImpulseAudioSpeakers]

pliedtka I agree with the wider baffle. Hopefully I can find to do that. The 4ohm thing I’m sure is just to spec brag that they can do 93db or what ever. These didn’t even make the sensitivity spec. So not that impressive really. In the end they usually always need padding down but in that rare circumstance that the rest of the drivers in the speaker are that sensitive then these 4ohm tweeters have a better chance of marching.

[@Quetzalcoatl0]

Huh now i noticed something. Tweeters size is measured by the dome width, but anything with a cone is measured from the edges of the gasket instead of giving the width of the cone + surround.

[@SheikhN-bible-syndrome]

Yep i learned that the hard way when i ordered 4 2" super tweeters and they required a 4" cut out to fit the box....

[@95Sn95]

To whomever cares there is a tweeter that imo is a really good ,durable and now super cheap tweeter mn# 160710 & kl-rd (I've seen it as both numbers?) it's a Klipsch soft some neo magnet horn and its also used in alot of BIC America speakers, I've heard them because there in all my BIC Acoustechs, I think there sweet sounding, clear & detailed but not harsh, there on eBay and Amazon prob elsewhere on a factory buyout for $11 each! it is just for the driver it doesn't include a 3 bolt waveguide, I bought 2 for backup tweeters for my BICs where there soooo cheap. But I'm getting a couple more for a diy bookshelfs, I bought an Eminence 2/3 bolt to 1 3/8" thread adapter so I can use the waveguide from the PRV WG175PHs I want to compare them to that I am on the fence with them, There good enough that If I could afford it I'd buy a bunch n stash em.

[@kek7778]

Great video! Could you test the Dayton Audio ND25fa in a future video? I wanted to know what you can really get for 10$ or less. The frequency response looks fantastic for this price.

[@ImpulseAudioSpeakers]

Michel Remmel hmm, I might have that one on my shelf. If not next time I make an order I should order a really cheap tweeter like this one for a test video. Good suggestion I’ll keep it in mind. Quite a list of videos ahead of me though.

[@kek7778]

@@ImpulseAudioSpeakers Thanks for the fast reply! The reason why I want to test this driver is that I'm planning to build a 3 way speaker with it. The other drivers will probably be a Monacor Sp-60/4 and Dayton Sd215-88a. I already designed a crossover for them and they work really well together.

[@tarekz9992]

Please throw some foam on the baffle and remeasure, that diffraction is nasty looking and I'm curious what the real response on axis is like.

[@ImpulseAudioSpeakers]

Tarek Z I will be adding round overs to the finished speaker and may test on a 200mm baffle with a round over. Foam isn’t a very practical form of diffraction control in my experience. Hopefully the finished product will control diffraction better when I’m done.

[@ThePentosin]

Maybe move the tweeter over to one side abit? Edit: this is already brought up in another comment.

[@ImpulseAudioSpeakers]

ThePentosin ya as mentioned with the other comment you saw, it helps but not a ton. I’ll use big round overs to try and help with that.

[@spasev]

Very informative. Thanks dude

[@edwardroman6844]

How did you learn so much about speaker building? I love your content. Thank you.

[@ImpulseAudioSpeakers]

College and years of screwing around. Plus speaker forums in the early 2000s.

[@Renrondog]

Breakup area and square corners on the test box, maybe? I used a 10uF and a 0.9mH inductor. It measured much flatter than your sample. I got lucky I suppose.

[@whocares3132]

Can you please measure SB acustics sb29rdc 4 ohm? its the best and low cost tweeter ever

[@ImpulseAudioSpeakers]

who cares I did the SB29RDCN if it interests you. I like it a little more because it’s almost the same performance but the neo allows for a really small faceplate therefore closer spacing to the mid or woofer. Check it out :)

[@kozkoz7776]

Have you used or heard of plasma tweeter back in the day (the 80 's) dating myself here was a company BIC believe was the name features a plasma tweeter I was purchasing a pow/pre at the time and auditioned this pair nice very nice did not buy them I had my speakers custom made

[@timothyhall7606]

I love a nice solid flange!

[@IliyaOsnovikov]

Can't you move that tweeter off-center? That might help. As I recall there is a program called Edge that helps simulate baffle difraction.

[@ImpulseAudioSpeakers]

Илья Основиков yes that could help but introduces other issues. The best is to roundover or chamfer the edges, which I’ll do in the final build. Edge is an excellent tool. Xsim also has a diffraction predictor if I recall correctly. They’re very useful.

[@IliyaOsnovikov]

@@ImpulseAudioSpeakers Agree, but at those frequencies (3500 Hz) a roundover or a chamfer has to be faily large in size to be effective. Am I correct?

[@ImpulseAudioSpeakers]

Илья Основиков yes that’s true. At least 3/4” would be good. I’ll be able to get an inch, maybe more on the final build.

[@ThePentosin]

What other issues?

[@ImpulseAudioSpeakers]

ThePentosin the other issues is that it only corrects the diffraction for one axis. As you move off axis it shows up again. Basically sharp baffle edges have diffraction no matter where the driver is on the baffle. A big round over actually reduces diffraction. The offset just moves the diffraction frequencies around a little.

[@murman229]

Maybe using a temperature controlled soldering iron would help. Cheers

[@ImpulseAudioSpeakers]

Manuel Muresan I didn’t think of that. Mine is not controllable. I’ve never had this problem to be honest. I don’t think it’s a particularly hot iron. Oh well.

[@MrChompenstein]

Thoughts on RST28F vs RST28A? I am thinking about one of these used in a SEOS-8 paired with an 8 inch woofer (peerless 830869). I am thinking SEOS-8 to perhaps achieve a lower XO, as the peerless woofer response gets wonky above 1.5K. audioxpress has testing for both available, but it hasn't entirely made the choice easier (I probably don't truly understand what I am looking at) RST28A seems flatter overall and maybe a bit tighter off-axis, but rolls off a bit above 10k. The RST28F tends to rise all the way to 20k after the hole at 2k and has higher sensitivity and lower Fs. I'm worried that the rising response of the RST28F might leave things a bit bright sounding.

[@ImpulseAudioSpeakers]

MrChompenstein the F isn’t bright sounding in my opinion. I wouldn’t worry about that. But I wasn’t blown away by the F so I’d try the A personally. I wouldn’t worry about the Fs difference either. They’re very close I’m sure, so it’s really up to you.

[@MrChompenstein]

@@ImpulseAudioSpeakers I was already leaning a little towards the A, but once the woofers arrive I can get measurements done on those to perhaps get a better picture of how they behave. Ultimately a waveguide means Dayton's FRD wont be accurate down low, I will just have to take the plunge on one of them. Also, very good info about the off-axis interaction with the dip at 3.5k. I will be sure to look out for that. Thanks

[@BostonMike68]

Someone was trying to tell me today that you can't cross that tweeter below 1900 hrz

[@steensuder115]

Would you happen to have first hand knowledge of the Dayton ND tweeters? ND13FA, ND16... the smaller ones. They're interesting because their body is tiny, allowing for placement close to a high-reaching mid - to provide the brilliance into the 20KHz+ area and also good for minimizing lobing I guess. There are not a lot of tests of these tweeters around.

[@ImpulseAudioSpeakers]

Steen Suder I have a little bit of use with the ND20 and a lot of use with the ND28. The little ones have to cross pretty high and that’s their downfall. Otherwise ya they are good for having very close spacing (thus less lobing) and are cheap enough to experiment with. I’m a cross low and cover as much of the 2,000-20,000 Hz range as possible kind of guy so the little NDs haven’t appealed to me much personally.

[@steensuder115]

@@ImpulseAudioSpeakers Thanks, the idea here involves the new SB MD60N-6 (currently for preordering) and crossing at 5 or 6K (3 way). I'm trying to find out if they're good enough in the top two octaves to spend time on experimenting. Little diameter could cater for wide dispersion and the high cross would minimize the impact of the low power capability. FYI, the MD60N-6 is preorder priced at ~€15 in Europe which makes it very interesting in my eyes.

[@goodgoat3096]

Don't all 1-1/8" dome tweeters have problems in the higher octaves, even the expensive Morel parts? Would a 1" SB Acoustics be a better choice, or does unavailability at PE come into play? Thanks for the hard work and great information.

[@ImpulseAudioSpeakers]

Good Goat in my experience not this bad usually. This tweeter is clearly breaking up above 15khz. Others can usually get beyond 20khz before they have too many problems. I don’t order from PE so the choice was not an availability issue. Another option may be better but this is what we chose so we’ll continue down the path and see how it sounds.

[@pliedtka]

P.S. that BlieSMa tweeters seem like something special - if we just had the $$$ and rest of the equipment to match their performance - haven't seen distortion measurements that low yet from regular dome drives. Ah, also how does Vance's test for Voice Coil compares to yours?

[@ImpulseAudioSpeakers]

pliedtka I haven’t had a chance to look at Vance’s testing yet. Good reminder though. I’ll try and do that tomorrow.

[@MrArnand]

Why do you actually use white noise, instead of a frequency sweep? What are the pro's and con's between them?

[@ImpulseAudioSpeakers]

Arnand de Jager it doesn’t really make much of a difference. The sine sweep I find works better at low frequencies, so I use it when measuring the bass response. White noise (MLS) is said to be better at filtering out ambient noise. I use both but probably prefer sine sweep if I could only have one.

[@machoheadgames8854]

Defective tweeter? Other RST distortion tests have looked much better. What was the testing SPL and mic distance?

[@ImpulseAudioSpeakers]

machoheadgames I haven’t seen any other tests but I thought this looked really good. Other than second order, the other orders are way down in the floor. Level was set for equivalent of 92db at 1m so I left the 2.8V input. Moved the mic to 10cm. It’s really hard to compare distortion tests which is why I rarely talk about them. I usually just throw the results on the screen and tell people to go back and pause to look. This time I spent more time on it because I’ll be working out a XO. So depending on how different they look I wouldn’t be concerned. This was a good results and out of all the tests done here it’s what makes this tweeter ok, unlike the frequency response.

[@pliedtka]

The only other test of RST28 was done by Vance for Voice Coil or Speaker Builder, unless there is a test which Google search doesn't know about

[@ImpulseAudioSpeakers]

pliedtka oh I’ll have to check it out. Been a while since I checked my voice coil account. I missed it.

[@pliedtka]

Hey, let us know what's different between your review and Vance's, other than infinite baffle in Voice Coil test - other than that they should be quite similar, unless there are production variances like in RS midwoofs you tested.

[@pliedtka]

hificompass.com/en/speakers/measurements Very good, infinite baffle measurements

[@MrGerson2026]

Will it be tested VIFA-TYMPHANY D27TG35-06？

[@ImpulseAudioSpeakers]

MrGerson2026 sorry I don’t have that driver.

[@BostonMike68]

What are the lowest you feel comfortable crossing those tweeters

[@ImpulseAudioSpeakers]

Hmm, maybe around 2khz depending on how it is done. Possibly lower. Also depends on the application. If you are using them for desktop speakers or background music, then 1500hz is probably ok.

[@BostonMike68]

@@ImpulseAudioSpeakers I was going start it hard at 2000 with a 3 rd order crossover and an Lap and it's going to cross the woofer at 1500 and the woofer I'm using a 3 rd order also so they are both dropped off really fast. But some people are telling me that the old rts28: was better and the new is just ok idk I never used either. But they are for my small bedroom for my TV and music it's like 10" from couch where I sit and watch TV and listen to music it's a small room around 12" 16" but I was pairing them with 8" Dayton audio reference paper cone they don't break up as made as the aluminum. I'm dropping the woofer at 1000 with a 3rd order and the tweeter at 2000 with a third order and a L pad and they are both dropped really hard so I think I should be ok . I designed it on xsim. They are going to get played loud sometimes with heavy metal so hopefully they can take it. Thanks again and are making videos anymore?

[@pliedtka]

Hi, I have question(s) re new Dayton and since you had some time to play with RST28 a bit how does it compare to other offerings in $50 - 70 range, like SB29RDC and the neo version, Scan HDS, Usher 9950-20 (old RS28F). How do you like the sound of the RST28F so far. I need something to go to 1.6k cleanly.

[@ImpulseAudioSpeakers]

pliedtka I’m not totally blown away by it, but it’s a decent value. I still like the SB better. Even the Vifa XT25BG is better value. Decent sound though.

[@MudFlap62]

Recently found your channel. Great content. Have you ever done a video on crossover components ? For example is a Mundorf silver gold oil cap really that much better than a Clarity cap ? Or a Goertz inductor that much better than a Madisound inductor ? I want to build my own bookshelf speakers just not sure paying a 100 times more for a component is worth the money. Thanks for your videos.

[@ImpulseAudioSpeakers]

Nowandthenagain hey thanks. I haven’t done a video like that. I don’t think buying those expensive parts are worth it. Especially if you’re starting out, just pass on that stuff.

[@pliedtka]

Most of the time waste of money. If manufacturers use standard parts in kilo $ loudspeakers then why bother. Better use of the money is DSP active crossover and good multichannel amp.

[@linandy1]

They pack those way better than Peerless Tymphany pack theirs.

[@joppepeelen]

all above 1% THD ? thats a weird measurement can you explain ?

[@ImpulseAudioSpeakers]

joppe peelen I’m not sure what you’re asking. What is weird about the measurement? THD is the total distortion of all the harmonics (2 to 5) added up.

[@frankgeiger7949]

I´m planning to build a center speaker combining this tweeter, a RS100-8 as mid and two RS150-8 as woofers in a "w(t/m)w-Design". Since i´m a beginner: is this a sensible combination/design? Educated opinions are appreciated :-) !

[@ImpulseAudioSpeakers]

Frank Geiger hi. The combination isn’t a bad choice. Using drivers that are better suited to roles as woofers and mids would be better. Also, no need to match brands. Usually doesn’t look as good as people think and has no impact on sound quality. Better to pick drivers that make sense. But most important, as a beginner, please do a 2-way. 3-way speaker’s are 3x harder to do and you chances of success and satisfaction with the process will be so much higher with a 2-way. Sucks to spend $300 on parts and get mediocre results and wish you just bought speakers. Even if you want a 3 way, do the 2 way first. Honest.

[@frankgeiger7949]

@@ImpulseAudioSpeakers That´s the difficult one: how do i recognize drivers which are suited for my project? I´m not set on dayton speakers, so what are your suggestions? Personally i would prefer a 2-way system but because of the special situation for center speakers that seems to be quite difficult......

[@ImpulseAudioSpeakers]

Frank Geiger ah, a 3 way center channel speaker. Even trickier. How about a design already published that you can follow along? If choosing the drivers is new to you, then crossover design will be too. If you pick a design that’s already worked out you’ll be more likely to succeed and learn a lot along the way. If you do want to have a go at it, then I’d use those Dayton drivers you mentioned cause they could be repurposed many ways. They’re jack of all trades drivers.

[@frankgeiger7949]

@@ImpulseAudioSpeakers I wanted to build a 2-way-system using the mentioned tweeter and woofer, but then i learned that most centers are actually 2,5-way systems to avoid the drawbacks of an d´appolito-arrangement of the drivers, but they have - spoiler-alert - disadvantages by themself. I actually looked for an already published project but i could´nt find a speaker which is max 8 inches high, better 7 inches......

[@juanmangerita]

All the measurements are cool.. But how does it sound?? At the end of it all the ear will be the best test..lol

[@ImpulseAudioSpeakers]

juanmangerita to me it sounds ok. I have other videos about using this tweeter and make some comments about it. It’s really hard to make subjective comments about a driver because it depends how it’s used. If I implement it poorly or match it with a really good mid etc I may have a different opinion. A complete speaker is a finished product that subjective comments can be made about. Even then it’s important to make sure it’s implemented into the room and system properly. But these variables, although huge, are much smaller than a raw driver.

[@РубаильСафаров-ю8э]

Hello. Can you show how you measure the dynamics through the microphone and with what program do you set the ZMA, FRD graph? Thanks.

[@ImpulseAudioSpeakers]

Рубаиль Сафаров I’m not totally sure what you mean the dynamics. Do you mean distortion? I use Xsim to load the frd and zma files to play with crossover components. There are other options but I find this to be the easiest and best.

[@РубаильСафаров-ю8э]

@@ImpulseAudioSpeakers How can I measure the frequency response myself and save as FRD and ZMA, through a microphone or through some kind of program?

[@РубаильСафаров-ю8э]

@@ImpulseAudioSpeakers in short, I need to measure my speaker and put it into the XSIM program, but how?

[@РубаильСафаров-ю8э]

@@ImpulseAudioSpeakers I mean to DRIVER

[@РубаильСафаров-ю8э]

@@ImpulseAudioSpeakers How to get FRD and ZMA?

[@raymondcooke5506]

Three thoughts: First, your off-axis measurements look painful to take! Time for a lazy susan? Second, instead of ignoring the hole why not design the crossover based on a listening window average? That works especially well to keep perspective with a coax or round waveguide due to the large axial notch. Third, since you're not chamfering the baffle, perhaps try some felt or foam around the tweeter to see if that helps with diffraction?

[@ImpulseAudioSpeakers]

Raymond Cooke all good points. One, I normally rotate the little stand on top but didn’t this time. Which is why I poked fun at myself during that part. Two, ignoring it is paying attention to the listening window. Much the same as the coax or waveguide example. I know that the listening window will be fairly smooth through there. Especially after I explain number three. But maybe I’m not quite understanding what you mean by this?? Three, I do plan on shaping the baffle. This was just a test box and will go in the garbage once I’m done with it. The final box will include hand shaped round overs. That will really smooth out the off axis response and make the listening window more uniform. Definitely good things to think about and happy to see viewers paying attention to those details.

[@raymondcooke5506]

@@ImpulseAudioSpeakers Thanks for the detailed reply! I missed that you were going to smooth out the edges on the final cabinet - though why roundovers when your tests showed chamfers worked just about as well? Aesthetic preference? I thought this box was the same form as your final one, and was thinking about earlier studies - David Ralph's for example - that showed how using felt or foam strips on the baffle can reduce diffraction effects.

[@ImpulseAudioSpeakers]

Raymond Cooke mostly how I want the final aesthetics to be. It’ll make more sense once they’re built. Hard to explain. David’s work is the best I’ve seen with the felt. I haven’t personally done much testing with felt so I shouldn’t make strong arguments for or against it. I think it has merit but man it’s ugly haha.

[@oraz.]

This is great

[@1stemax]

great job

[@hardcorecap]

oof, PE's using some 40C solder to make speakers lol

[@larrygaines7462]

Use terminals no soldering ,damages construction...

[@ImpulseAudioSpeakers]

Never had an issue before. I prefer the security of solder. Both work though.

[@linandy1]

Use female spade connectors and no problem.

[@dgjm7129]

this guy looks like big face JacksFilm

[@ProfessorOzone]

You need a Lazy Susan.

[@kdsf12]

The terminals melting is a huge turn-off for me.

[@ImpulseAudioSpeakers]

Shane Fage ya I agree. It made the driver feel very cheap. All 4 did it.

[@kdsf12]

I agree. I'm out.

[@kdsf12]

@@ImpulseAudioSpeakers I have had a couple of my own reviews of the precision devices drivers published in the last 2 days. I wrote in a very different language than is normally associated with loudspeaker design... of course, on purpose. PD published my reviews and so did Chris over at Solen.

[@marklowe7431]

Sol der.

[@charlieturner5485]

I've lived in both Indiana and Colorado, no L pronounced in either place. It's a regional thing I think. Funny thing is, I have never heard anyone pronounce the B in plumbing while they are talking about soLdering the plumbing parts together.

[@davejones4740]

Cheap terminals that move when soldering. I suspect this wouldn't happen when paying more .

[@johnsweda2999]

I don't know why you and other people waste your time with this cowboy company Dayton audio, what a pile of rubbish just use proper good quality driver manufacturers. I suppose you're sponsored by them seems to be the case on KZbin forgive me if I'm wrong, Like you show anyway just use better quality! I would like to see the linkwitz lx521.4 build, not something I've found on KZbin anybody know any builds! let me know! I think that would be the great build with the active crossover multiple 50Wamps, and ASP build any chance in the future.

[@ImpulseAudioSpeakers]

John sweda not sponsored. I paid for these drivers myself. I don’t use Dayton very often but they do offer good value. I generally prefer SB Acoustic for this price range though.

[@gzubeck3]

SB Acoustics, Seas domes, and possibly Beyma amt drivers.

[@ThePentosin]

Whoa there. You went from really good bang for your buck to "Holy Shit this amazing tweeter is expensive"

[@gzubeck3]

Yes, the Beymas are expensive but they also make a Q$200 amt tweater but it doesn't cross as low and the power handling is not there. I should have also added peerless (vifa) tweeters as well because they do have some good value propositions. I should say that seas does make some good $50-70 tweeters that can compete with the sb acoustics.

[@ImpulseAudioSpeakers]

George Zubeck the peerless stuff is quite good. They deserve more attention. In the 90s vifa is all people used and they’ve slowly taken a back seat.