Bad Speakers Start with This. 🛑 Flush Mounted vs Surface Mounted Tweeters. Why it matters. 

For those asking this question repeatedly in the comments, his review does not apply to tweeters with a waveguide. One of the specific design goals of a waveguide is to greatly reduce if not eliminate altogether edge diffraction.

I really like these generalized videos. Makes it a little easier to weed out speakers right off the bat. Excellent video. 👍

oh dear poor edifier haha. Actually I wouldnt be too quick to dismiss the speakers shown in the images and thumbnail, while they do suffer from the issues described in this video, they are very cheap and perform well within their price range. Even Amir from ASR put the R1280T on his recommended list.

This may not be a desirable fix for alot of people, but I've fixed a surface mounted tweeers edge defraction by adding black foam strip (1/4" wide 1/8"tall) to the outer edge of the tweeter flange. Then I added it to the outer edges of the flat front baffle. Just applied it down both side running top to bottom. My speakers baffles are black, so the narrow black foam doesnt look bad at all. With just this minor mod the speakers came to life. The mids and highs instantly sounded louder with more detail, especially at lower volumes. I'd rather have flush mounted tweeters, but for now this works

It may not be new information Erin, but it’s always going to be new to someone. And your concise, easy to follow explanation is very helpful. Really appreciate all you’re doing for those of us interested in all things audio. Many thanks!

The only time a surface mounted tweeter might not be bad is when the grille frame is designed to fit around the tweeter face, creating a smooth transition. Paradigm and some others have speakers designed like this.

Good advice for the DIY crowd as well. It's not just the sound, they look so much better flush mounted too.

Erin in a very short period of time, your videos have become one of my favorites! Why? Because you're realistic, explain speaker/sound characteristics with the inclusion of some empirical testing, room dynamics - on axis and off axis. The best part is I actually understand what you're explaining; that understanding coming via my own ears, in my own home. Thanks!

Amazing how much of a difference a few mm can make! Thanks for the video 👍👍

Here's an idea - arrange a simple test to see if anyone can hear the difference between a flush-mounted and surface-mounted tweeter in the same speaker, all else kept equal. Should be easy to arrange by adding a simple cardboard shim behind a flush-mounted tweeter to emulate it being surface mounted. How many people do you think will be able to hear the difference?

On a blind test, can a person differentiate the flush mounted and the surface mounted?

Great video, particularly after I had the same question regarding the unusual surrounds on some of the Purifi drivers in your last video. As you, it has been discussed in the past, but I have NEVER seen an actual A-B comparison of the same driver like you've just presented. Man, I can't get enough of actual objective measurements and what they mean and how they impact sound and performance. I don't know how much you paid for that Klippel scanner - but I'm so glad you did....

That's surprising how much difference it makes for something that seems so small. Great work Erin!

Picture in the example i belive is Edifier 1280, and i think that all from 1100 to 1850 has surface mounting. But they are still among most sold and highest ranked budget BT active speakers under 200usd.

First timer here. Like others pointed out. Who cares if it is not new information? It's your interpretation of this fact and as for me I was very pleased with your way of putting things in perspective. This will help in my first build I guess!

First of all, forget the graphs, if you like the sound of the speaker system go for it. I have the Edifier bookshelf speakers in use as my recording studio monitors and love em! I have Altec VOTTs as my main speakers driven by KT88s and after all these years, I am still in awe! Let your ears be the ultimate judge!

I'm curious how much it is influenced by sharpness of the edge or even the step distance. For example, can you radius the edge and drastically reduce the effect? And if that step down is moderate versus thin, how much does it matter. And is in the flange edge specifically causing the problem or what happens after? For example, if you have a flange step but the step down is a soft surface, does it modify the effect? I'm mostly curious what critical elements of the construction matters. The distance should affect frequency of influence, but what happens next? As a second part to this, I might expect the evenness of the edge distance would amplify the effect. But if that edge distance was non-linear, for example an oval flange or star shaped, would that reduce the magnitude of the effect? Would it damp out the behavior over a broader frequency range? Why the curiosity? Because we're not just talking speaker flanges. We're also really talking about enclosures too. Your enclosure size, your edge treatment, and even where you place the driver should influence this same effect. Do you install a tweeter center or offset slightly ? Do you purposely keep it away from edges as to not be right at the very top of the cabinet? At least through some operating range of frequency, this should matter. And if a 4" flange matters, most folks might have their tweeter, even if flush mounted, 2" or less to one of the corners of their enclosure. Should they worry? Should they change how they fundamentally place drivers into the enclosure face? (for example, MTW versus TMW) If the flange matters, the enclosure matters.

Not being an audiophile, the Edifier powered speakers sound good paired with my computer.

I have triangle zetas where the tweeters appear to be more recessed so it's a bit behind the baffle. To me it sounds fine, not perfect but fairly well balanced. Like many metal tweeters, it can accentuate sibilance at times but tonally, for voices it does a fine job for budget speakers..much preferred when compared to borea 2

Thank you for your informative video, Erin! Years ago, I used to make frequent visits to the Zaph Audio site you mentioned, and I liked it a lot for its data and general info. I also visited Seigreid Linkwitz's site and read his material on loudspeaker data, implementation and radiation patterns. I like these topics, and you are superbly presenting this subject matter in a very engaging and fun way! I thank you! 😊 🍺

Really enjoyed this quick 'primer' style video on a specific subject. Thanks for sharing your knowledge, Erin 👍

This mounting design is usually on powered desktop speakers under $200 like the one you show in the video. I have a pair of Edifier R1850DB that I bought on sale at Amazon for $140 a few years ago. It has the tweeter and woofer surface mounted. I use them on my computer desk connected to a DAC into a my desktop computer. It sounds good to me for the price.

Again thank you for such informative videos and explaining design flaws on speakers design! Based on your reviews, scientific data and recommendation I purchased a pair of KEF LS50W II on sale without listening to them first! They are great!

So I have a pair of JBL L-100 centuries, arguably the most famous speaker ever made and certainly a well designed and great sounding speaker. This speaker has the tweeter and the mid range driver surface mounted as you describe while the woofer is flush mounted. I think there are many other factors that are far more impactful on the sound of a speaker than whether it’s elements are flush mounted or surface mounted. I will say it is an interesting exercise in measuring these differences, but by no means is this one characteristic something that should automatically qualify or disqualify a speaker especially without hearing it.

That time laps of microphone testing is awesome. The work that goes into acoustic tuning is insane.

So - EVERY auto audio system has the speakers surface mounted, and almost every tweeter is mounted in a pod that sits up to an inch from the surface. There are some very good auto systems out there. I agree with everything you are saying, but there are hundreds of thousands of great sounding systems in all sorts of auto, marine, off road, and aviation with surface mounted speakers! Just being real not trying to argue, as I love your videos.

You should look into how Paul Barton and PSB have dealt with surface mounted tweeters. They designed their grills on some models with acoustic felts padding that allow the tweeter to become flush when they are attached. They use to include a little card saying to keep the grille on. They talk about it on the 50 year doc they've just released.

Lot of good technical info but at 89$ the Edifiers in specific sound really great and not only for the price, and I have them side by side with a pair of JBL HDI towers

I knew I flush mounted all my speakers for a reason! 😉 good info man, thank you

Your channel is definitely one of my favorites in audio because of videos like this

So, in laypersons terms, the sound wave "trips" on the edge, and the open screw holes, and this causes part of the sound pressure wave to be slightly out of phase with the initial sound pressure wave. Depending on the frequencies, this may be in phase, or 180 degrees out of phase, which will increase or decrease the strength or the pressure wave (sound level), but will mostly add unwanted interference with the primary sound.

Could use much more visual reference for flush mounted designs here vs the other just to make sure we can tell the difference but this great, loving your channel for certain (I just don’t have energy to do this + visit your site is all).

There is a term in speaker jargon called "fatiguing". An overdriven, poor speaker may not sound bad at first listen, but makes the ears tired over time and not a joy to listen to. Well designed speakers don't do that. I'm guessing the flush mount is one of those subtle things you may not instantly hear. Now I need to rebuild my first speaker boxes and see. The sound is pretty dang good, but the enclosures could be better.

Anyways, that Edifier speaker is not classified as a hi-fi product. More likely a midclass computer speaker. I have one 😅

Literally my desktop Edifiers.

Magnepan- surface, baffle mount? Psh. Kef uni-q drivers-np, mount em in the center of the woofer, perfection. Sooo many different variations. I do like externally mounted tweeters separate from the cabinet alot, especially dipolar ESS etc.

My Klipsch KG2s use flush mounted drivers (with the woofer overlapping the tweeter). There was clearly a lot of effort put into designing these, and they weren't low budget speakers designed around production cost. Now, the tweeter is horn loaded, which changes the equation a bit. My opinion (everyone has one) is that the room is the elephant in the room. You won't hear the difference in baffle configuration if your room is not good.

When I flush my toilet it sounds pretty good!

Been building, designing audio since 1971,retired now, in wheelchair, took a month to build last system, new tactics for good construction. 2.1 's only. I vulture tech, and DIY like the Chinese

You are right, the pressure zone leaves the transducer and jumps producing the air movement hopefully reaching your ear with some wave forms that resemble the intended sound from the artist. Technology/art..Like my photography....

You're most likely correct , plus flush mounted looks better too.

Erin thank you for bringing this to my attention: my custom pillars are not flush mounted and this is my next goal on my updates

I noticed that your scanning microphone was working very close to the tweeter, where you might expect diffraction effects to be the greatest. Also it didn’t seem like your apparatus had enough vertical travel to represent typical listening distances. Does the uneven response hold as you move out away from the speaker, or does it smooth back out? Your graphs likewise gave no distances.

A 3mm edge starts playing at about 28kHz imho. Is this true and is this a real show stopper? For CDs may be? ) About your measurements... Do you really thing that such big difference at 2kHz (6") was caused by that 3mm edge, and not by something else?

For me it all depends I buy components and I place them in different places in the room on sticks with magnets. I changed the positioning of my sound with the treble. I like the HR24 mackie tweeter with the laser wave guide. Surface or flat mount or flush. It doesn't matter if you have a grill though. I have definitive technology the original flagships from 1996 and I can never see my speakers unless I rip those socks off. It's a beautiful set up and I never really get to look at it unless I shine a really bright light.

Good point! However, the Dome Tweeter is the Main reason that high end dynamic speakers have put high end audio back back 40 yrs! never been able to compete with good ribbon,or Horn Designs.I have some of the best sounding Dome Tweeter designed speakers in the industry! NO. 1; Celestion,Who Designed the first Metal Dome! That incorporated a slotted waveguide over the dome to minimize vertical reflection problems! NO.2; JM LAB/ FOCAL,who redesigned the Dome Tweeter,Creating a reverse dome that doesn't see the baffle at all! Used In Most Wilson Audio designs ( I have FOCAL Speakers ,and Separate Drivers) I build speakers,been doing so for some time! My Best design utilizes a ribbon Tweeter that also can't see the Baffle,and Horns,that also can't see the Baffle! So who Cares if a convex Dome is Flush Mounted or Not? It still has diffraction issues!

This is true. many moons ago, a good Danish Hi-Fi magazine tested a bunch of speakers vs the same speakers with an experimental 30mm rockwool damper front with cutout holes for the speakers and verified a dramatic increase in sound quality due to the sudden loss of edge difraction, Verified by very accurate and detailed measurements. The effect was described as switching from a cheap speaker to an electrostatic one, and Its true.

Love a video where the first 5 seconds is all I need to watch.

There is also a deflection point in the mortise between the driver face and the baffle. If it actually mattered, every tweeter would have a face that tapered to nothing on it's outside edge. To say that you can actually hear it is woo, plain and simple.

Now I went back to check the spinorama of Edifier 1280T and it seems to have the exact issue at the treble. Interesting.

Does this only go for dome shaped tweeters? or are more traditionally shaped paper cone tweeters also affected? My technics sb-a55 speakers sound really good to me, but they have huge surface mounted rims around the drivers, massive plastic rings that the speakers are recessed into.

i am impressed by how the mounted option flush vs surface can be seen on the measurements! thanks

Thanks for this info ,found it useful to spot cheaply made speakers,even by established brands at times

I'm a big fan Erin. Your videos have such valuable information. Not only informative, but also well produced. You are a kind and humble person. Question: Would it be a better idea surrounding the tweeter with damping material or flush mounting it?

The whole video i was breaking my head what's on your tshirt man .... Thanks a lot for clarifying it's saw dust. Now I'm at peace 😂😂😂😂👍👍👍👍

Thank you. The truth is always in the measurement.

Erin's assertions are not incorrect, but these refraction don't necessary determine a good or bad speaker. There are many high end excellent speakers that have surface mounted drivers. Agreed, flush mounting will reduce edge diffraction which occurs when the wave reaches sharp edges. This is more important in mid and higher frequency drivers and usually you don't need it except for looks in (large) bass drivers. But edge diffraction will also occur when the wave reaches the end of the baffle, hence a reason for beveling the baffle edge. The width of the baffle determines the baffle step and the curvature of the edges determine to a degree how smooth the transition between radiating in half to full space is.

Too bad the speaker selected as a bad one at 8:45 is an Edifier, because is actually quite a good brand. They have cheap with surface mounted tweeters and up to a point in price and style they have with flush mounted tweeters and quite good speakers. And not only that but they have a higher end brand (if you want to call it that way) called Airpulse that have quite impressive speakers. Thanks to having those cheaper ones, people on a very tight budget can have a pair of good enough speakers, with build and components quality, that last, unlike other cheap brands, and if you have more money, really good ones. I have a set of Edifier and mine are kind of in the middle, the model is "C200" and the tweeter is flush mounted, to me, but still has an outer ring that sticks out just a milimeter, probably just for decorative reasons. Wonder how much it affects.

Excellent video!

This may be true with most speakers, but Tekton Designs has surface mounted tweeters on their speakers and they are amazing so how is that?

I'd like to start by stating that I really appreciate your opinions because they are typically based on logical thinking and measurements. I've built a number of speakers, reflex, back loaded horns, MLT, etc. A number of my builds use Fostex drivers that have a cast frame with a beveled surround, an example would be the FE-208EZ. Do you think there would be any benefit in insetting the driver so that the beveled edge meets the baffle? Does the 1/8" shoulder on these drivers significantly impact sound quality? I always inset my tweeters so that there is no shoulder above the baffle, but this video got my thinking about the other drivers. Thanks for your time!

A way to mitigate this issue, especially if you use your speakers with the grills on or just don't care how they look is to tape foam around the tweeter, I did this to a pair of Edifier speakers my brother uses and could notice a clear reduction in the sibilance, I literally took spare foam tape that came as a sealant with the kitchen cooktop and glued around the tweeter it's similar to the foam tape we use to seal speakers in cabinets in DIY and in car audio. It just happens to be of the perfect height and since it's foam, it kinda absorbs a lot of the sound, I don't actually have acess to equipment to measure how much of a difference it made but if you find it interesting, I sure would be interested in seeing this measured, if for nothing else, at least to be sure me and my brother actually heard a difference instead of just falling for placebo effect. I don't think it was placebo, it was a very noticeable difference but it doesn't hurt to be sure. I don't recall what speaker now, but I've seen a speaker brand integrate foam on the outer edges of their tweeter facia and that gave me this idea.

I'm a fan of the waveguide mounted tweeter - if implemented well - myself. Get's more efficiency from the tweeter, all things considered

Thanks Erin! Is the same true for different tweeter designs (horn loaded, ribbon, air motion transformer, etc.)?

I agree, wholeheartedly with your theory, and testing; and is actually another reason I APPLAUD whosoever designed Amazon's "Amazon Basics 80w RMS Bookshelf Speakers" which I now use as my active monitor solution and replaced my Paradigm Titan V2's with around a year ago. Since their release these speakers have jumped in price (as I predicted in my review) from $53 to over $250 and they're worth every penny in terms of sound quality, frequency response range, signal to noise ratio, waveform, and overall capability of the speakers. Granted, I'd have a MUCH harder time convincing myself they're worth what they sell for NOW, but they're EASILY worth $150 compared to some of the crap on the market being sold as "monitors."

Totally agree. I designed a well reviewed loudspeaker about 8 yrs ago and it has unusually good dispersion matching between mid-bass and tweeter. However the baffle is narrow so diffraction has an effect. I'm thinking about a new version with a waveguide, not for matching to the mid-bass but simply to minimise baffle edge diffraction. It can take as little as a 10mm deep waveguide to help a lot. It's what happens off-axis with diffraction that often goes undiscussed.

Thank you for being awesome and so informative! What about inverted, flush mounted tweeters like you see on Focal speakers? What difference does the inverted dome design make? Thank you again.

Interesting video my towers have dome flush tweeters they’re old school but I love them sounds amazing to my ears.

Actually I just finished a Peerless/Dayton silk dome build.. Ya maybe one day I can flush mount the truncated :/.. I've heard many speakers. I find it hard to believe, these are the best sounding speakers for music, I've ever owned for a budget price. Not a perfect build. That's what happens when you go though many low budget, low end models. I guess you don't know good sound until you hear it.

That's nothing, you should see the up to 2cm thick frame in front of this iPod dock I have. They they even used nice little coaxial drivers, but sound is tarnished by the aesthetics design.

Good info but I do have a question. What about if you make a 'waveguide' for the tweeter; meaning, the tweeter is surface mounted to baffle A but then you have baffle B that sits atop baffle A with either a roundover or chamfered 'waveguide'? Also, what would be better in this scenario, a roundover or a chamfer?

Even my $40/pair Dayton Audio B452-AIR speakers have flush-mounted AMT tweeters. 👍

Horse schidt. Mounting position of the tweeter is dictated solely by the phase-shift, induced by the type of crossover that's used. One size does not fit all, Scooter. Jussed sayin' 😶

That Peerless DX25 is a good value priced tweeter. Been using them for years.

The reference speaker used is edifier 1280db.. so we must avoid buying effort l edifier 1280.. Thanks

The term you were looking for at around 6:40 .. "de-embedding."

Thanks you so much for coining the term 'equalizable'. This explains alot.

And also equalizable word should be recommended to be added to dictionary your honour 😊😊!!! Jokes apart ... Great job Erin !!! Love your objective measurements, explanation and videos 👍👍👍😊

Excellent info as always man, excellent.

all that work i put into buying router bits and tools pays off. and its a nice finish. could someone also mention some options to fix it on existing speakers please? heard people use felt and stuff like that, even a Dremel with the right bit could do this.

Great stuff as always! Any plans on getting those JBL 530s on deck for analysis?

Real tweeters consist of compression driver and horn. Everything else is not even pro stuff, but childs play.

I flush mounted Tweeter, Mid range, and 12 inch woofers. right into the drywall of my room. sounds increadibl. no port.

Absolute excellent video Erin and well explained..

With dsp and cabinets using multi tweeters or hf drivers that will cover the hi freq spectrum your mot going to notice anything in fact in a array column design comb filtering knocks down the hf anyway unless it had a wave guide fitted

I have the Ediffier speaker u shown in the video. They sound good, I have no issue with them. 👍 Notice the tweeter sits inside the cone shape radiator which spread outwards. It’s not even the same design u have shown in your flushed tweeters. Unless u have an Ediffier and show us the test result, I am not convinced.

It baffles me why anyone would surface mount a tweeter 🤣😅😭

I have an old Dunlavy SC lll speakers You should see how the intergrate their tweeter to the enclosure! Great vid with good valuable information 👍

Erin, what about Paradigm Reference Studio Series speakers? They all had tweeters on a protruding plate. But with a grill in place they could be kind of flush mounted.

Erin. Your content is amazing. Full stop.

The human ear is not picking up those differences.

What would be the effect of making the tweeter flush by sticking like foam or something to the face of the baffle to make it flush? 🤔

Thanks, appreciate learning from your channel

It is actually more about the quality of the Drivers and componets used than few mm differences in mounting. Most speakers would really benefit more if proper crossover components were used. Sadly in most cases this is not the case.

You should go over bad speakers configurations. Example like midwoofer tweeter woofer.

is this true for tweeters/high frequencies only or does it apply to midranges and woofers as well?

I'm new to audiophile quality, so I just did a double-take on two recent used purchases - a pair of Mission and M-Audio - and both are flush mounted! Sigh of relief - lol.

There are many design elements that are a factor in a speakers potential. If a tweeter is flush mounted, but the rest of the design is crap it’s probably not going to sound very good. Likewise, if an otherwise we’ll designed speaker has a surface mount tweeter it’s not necessarily going to sound bad. You are kind of over-stressing the influence of one factor.

Drivers mounted on the back of the baffle are worse. Have you ever heard the original Klipsch Heresy? The horn was rear mounted, with that smooth curve slamming into the squared baffle. I have never heard worse diffraction!

Really well explained thank you!