DIY Speaker Kits | Avoid These Problems And Getting It Right!

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Tech Talk 15: • Tech Talk 15: Crossovers

[@superdavett2]

Taking apart other peoples work (literally and figuratively) has become a significant part of Danny's business model. It is what it is. In Danny's defense, any sort of decorum in this area of hi-fi went out the window long ago. There are forums and YT channels galore with bloviation and criticizing of others speaker designs.

[@cruise2023]

I think before rubbishing other kit designers work, one would need to look at the original Troels Gravesen " 8008 corner " design on his web site. The one Danny is looking at is a redesigned cabinet built by the customer, that fails badly in more ways than one. This unit should not be compared at all with Troels original design, when in fact may have worked well for what it was designed for. Besides Danny's vid pointing out the flaws and corrections ( I agree with ) the other option ( probably most obvious ) I would point out to the customer, rebuild the cabinet to the original specifications and keep the rest as is, then make a decision !

[@BruceCross]

The customer who lied and claimed they built it properly? They wasted everyone's time.

[@hjnorlander7124]

From TG's page about this build. "A third options may be to build the cabinet without braces and from e.g. 15 mm Baltic birch or similar and make a "thin-walled" cabinet, e.g. Spendor/Harbeth style. What you get is a resonant box and it has its followers. Not my cup of tea to have the cabinet adding to the overall sound. If you do so, please report back and tell me what you hear. There are all sorts of unsubstantiated claims in hifi and to my knowledge nobody has ever build the same pair of speakers in two versions, resonant and non-resonant, and made comparison."

[@dannyrichie9743]

My measurements matched his very closely. Both show a lower output from the tweeter than the woofer. So it wasn't just about the box issues. The imbalance is also not at all ideal for near corner placement. It was also part of his design to center the drivers down the middle of the box with a wide baffle.

[@howardskeivys4184]

👍

[@CollectingRetro]

Yup, great speaker if you build it properly and use as designed. The kit also comes with resistors to adjust the tweeter level. A friend that had Devore Fidelity O/93 thoroughly enjoyed them in my system. It would be interesting to hear Danny's crossover, but they don't sound deficient in any way as they are.

[@stephenyoud6125]

Danny - for bracing cut from 3/4" MDF and 45 deg end cuts. I would look at gluing from sides to back and front but also glue the braces themselves together so the side of the brace going forwds is glued to the side of the brace going to the back panel. that will add a bit more rigidity to the joints to the side panel. I'd also look at using polyurethane construction adhesive as that will also have a bit of inherent damping on account of its chemistry.

[@thespotlightkid1011]

In the early 70's, I remember more than one of my dad's hi-fi mags advertising a concrete cab'd speaker. No idea what they would have sounded like, not woody but maybe concretey, the idea never got popular, tho I'd have liked to have heard my old Tannoy D.C.s placed in the wall between living room & the outside world as the cab' but for the neighbours, the large flat owning housing society where I then lived, would not allow my request to jigsaw out two 15" holes between living room & the bedroom come speaker rear-wave massive cab/bedroom. I should have just done it on that (non' load-bearing wall) ..& then covered it up well when I moved out.

[@aether-elephant]

​@@thespotlightkid1011 (only for rock mixes)

[@darrenmarrable2530]

Hey, a huge huge shout-out for your channel. Absolutely superb. It really surprises me that high-end speakers at higher end prices actually con us laymen into believing that their product is superior to others due to... their name... their prestige and their marketing, to make us bel8eve that we are buying a greater product. When in some circumstances you are buying an inferior product with inferior components. Simply jaw dropping until s9me one with your knowledge and expertise opens our minds t9 these terr8ble behaviours. Thankyou. I can't wait to watch and learn more from your previous media and attempt to build a great speaker. Thankyou all thr way from Australia, Gold Coast. 👍

[@albertorobinson7611]

cheers , hope have some of you thought on the kick start proyect towards tuning!

[@AllboroLCD]

I just spent $50 on 2 6.5" plastic basketed pyle DVC subs, yup, Pyle.... they sounded horrible at first! Then I built a mini vented cabinet for them and they just woke up! So impressed, Im planning to buy 2 more and build them into a butcher block coffee table in a "dual opposed" sealed setup and juice em with a 500 watt dayton plate amp. I think the results will be extremely positive : )

[@yvesboutin5604]

Hi Danny! I totally agree with you that cabinet design, rigidity and placement are essential to a realistic musical enjoyment. I have seen so many good quality parts being put in a flimsy cabinet with sometimes no damping at all. Contrary to a musical instrument where the casing is to vibrate to amplify the sound wave, on a speaker, the cabinet must be inert to not add its own vibrations with the ones produced by the drivers. This is also one of the reason why modern cabinet design use a narrow baffle to avoid surface reflections. Thanks again for the education value of this video! Sometimes, things must be repeated again and again before it becomes common knowledge. BYE !

[@thespotlightkid1011]

An excellent informed guide to bracing with aspects I was unaware of. Until I heard speakers without boxes, I never knew the amounts of box colouration I was always hearing, they were panel e/stats of 3 different designers, my fave being s/h imported 4 panel large e/stats by Accustat, full range each & driven from their dedicated valve energisers come power amps which sat on the low shelves backside, with their valve anodes wired directly onto the panel units stators, Gr8 sound but the sub 60'ish hertz bass drops out needing a sub I could never seamlessly blend in, so they're stashed in spare bedroom with some others, they made me think O.B. normal coned speakers may be my final ever ideal speakers with real bass, till then, I'd like to hear extremely well damped versions of Box speakers I deemed "too good to sell for what they fetch" like Celestion 2-way long ribbon hybrid boxes (Cel' 3000's) which cross over at 900'htz, a lot for a woofer / mid but they did sound Gr8 for their s/h priced sound but boxy bass that I now think are worth damping to the hilt, in the style hear explained, with minimal box-volume reduction. If I could get my Tannoy D.C.'s cones re edge- terminated, they would be my prime candidate for all this treatment, esp' with their thin wooden walled cabinets like they have. All panel ribbons or e/stats I've owned all disappoint me in the deeper bass, which somewhat destroys the sense of the size of venue a quartet or symphony orchestra or a band plays in, for just 1 shortfall of deeper or cab- resonance' from the deeper frq' extra' air-moving notes resonating cab walls. I heard that sound moves 4 or 5 times slower through helium, but can't think of a way to send the rear wave into a sealed cab of pure helium & regular long haired sheep's wool!!

[@robanderson6173]

Thanks for the explanation on the cabinet pitfalls. I wonder if laminating mdf from the outside would help. A new layer of baffle could get rid of that ridge on the baffle edge.

[@blackdaan]

yes that works.. i have made speakers of thick mdf. braced. and the inside has a layer of rubber bitumen. and foam.. i can hold my ear against it and hear near nothing.

[@stephenyoud6125]

or just use a Router and cut the front beading off and then do a roundover. but Dannys crossover would then be disrupted

[@petertimp5416]

Thanks

[@aether-elephant]

great video.. thankyou!

[@stephenyoud6125]

Outstanding job again and thanks for the tips and explanations.

[@myturkishlife1777]

Would it help by placing hi density foam on the front baffle or even leather or suede? Really enjoy these videos... Kind regards from Turkey 👍

[@dannyrichie9743]

A layer of felt can help in some frequency ranges.

[@myturkishlife1777]

@@dannyrichie9743 would love to see a demonstration of this ... Of course when you have time... 👍

[@yngve6640]

I'm Norwegian, and that woofer looks like a SEAS build for the Danish Truels Gravesen kit speaker constructor. It's an SEAS Excel based woofer made at Gravesens wishes for higher efficiency. I believe he wanted a woofer for small watt tube amplifiers. Like the woofers in Audio Note speakers. Audio Note speakers for tube amps are build to stand in the corners of the room. So this probably was Gravesens aim with this kit ?

[@dannyrichie9743]

I've heard the Audio Note speakers at a show with their gear. The speakers were in the corners of the room. In short, it did not work. The sound was flat (no depth) and sounded like there was a speaker in each corner.

[@CollectingRetro]

I can attest that these speakers work excellent with low power tube amps. I built them by the book and they turned out excellent. Far better than another kit using the same tweeter. Easy load for 3-4 watts of SET power in a small room. Using no braces seems like a HUGE mistake and they certainly don't sound dull in my system. The kit also comes with a few different resistors for the tweeter output to adjust to room/preferences.

[@kenthomas1613]

Just a thought. Some people would possibly love a speaker design with higher quality (slightly more expensive) drivers than the ones you always use. Something that’s from say Scan-Speak instead of drivers that you buy in bulk or from other loudspeaker manufacturers that have a tonne of drivers that they need to off-load. I personally would love to see a design based on Scan-Speak Discovery line of drivers with their new D3004/602200 tweeter. Sometimes customers want a more premium offering.

[@mcgovernjimmy]

Right now, I'm listening to one of Danny's drivers - M165NQ in an enclosure with the Dynaudio Esotar tweeter. The woofer in the enclosure was the perennial favorite, Scan-Speak 8545 woofer. The M165NQ woofer that Danny designed absolutely outclasses the 8545 in midrange clarity, and still plays well low. The 8545 may play lower, but it is outmatched in the clarity department. It's immediately discernible and I am not new to Scan-Speak drivers. In fact, I like Scan-Speak drivers. I have 2 other speakers with Scan-Speak drivers, one of them uses Scan-Speak Revelator drivers including the 8" Scan-Speak woofer with Revelator tweeter in a 2-way application. Perhaps I misunderstand your comment... but that M165NQ driver that Danny sells is exceptional and not just some "good for the money" driver. In fact, the NQ driver is so good that I would view it as a very significant $$$ bet to buy a 6.5" / 7" SS Revelator driver and think it's automatically going to be better than the GR M165NQ driver. The M165NQ only needs a single cap and inductor (2 parts) for the network... the natural response from the driver is already there, just by its basic design.

[@dannyrichie9743]

Our drivers are already better than the Scan Speak drivers in many areas. They certainly sound better. There is also a reason we can sell them at a lower price point and it has little to do with cost to produce and more to do with less markup. Part of it is that we have no dealers or distributors in the mix doubling the cost to the consumer.

[@kenthomas1613]

@@dannyrichie9743 OK. Just one more follow up question then. If you were to design a more expensive, more up market, more luxury loudspeaker for those that love your design skills like me and don’t mind spending more, what would you do?

[@TriAmpHiFi]

@@kenthomas1613 . Shiny, polished African hardwood cabinets, Mag-Lev isolation feet and unobtainium driver cones, of course. Acid Jazz, Funk & Brass 🔈🔉🔊

[@mcgovernjimmy]

@@kenthomas1613 I think he already has with the NX-Otica and NX-Treme. If those don't look exotic, I don't know what does. I suspect the real question is what you define as "more expensive, more up market, luxury"... and maybe you're thinking of a box speaker like a floor standing Wilson audio. That's the thing... spending more money doesn't always equate to "better". Some think his NX-Treme speaker is the best speaker on the planet... don't let the fact that it doesn't cost 5 figures fool you into thinking it's not already the best.

[@freeradical6390]

Great vid Danny! I like doing ladder bracing front to back, top and bottom of each driver. Rails and stiles.

[@alexz1232]

I would love to see a video comparing identical drivers and crossover in 2-3 cabinets of differing quality levels. There is a lot of measurements of finished speakers online, not many that focus on specific variables.

[@joeygonzo]

Kits intrigue me but my ADS L810 sound so good

[@EskWIRED]

I had a pair of 710s back in the day. I enjoyed them greatly until my apartment was broken into and they were stolen.

[@joeygonzo]

@@EskWIRED damn! I just missed out on a good pair for $300.

[@lastweekslightning]

Have you done the Triangle Borea BR08? I have a pair and been in love with them for a couple years now, but would love to know what I could do to even improve them.

[@dannyrichie9743]

We took a look at the Borea model. They needed help, but were too hard to work on and almost impossible to remove the drivers.

[@MrTeff999]

Would mass loaded vinyl be a good box liner? I ask because I have a 25 foot roll of 1/4” that cost me a small fortune.

[@dannyrichie9743]

Yes.

[@Kulumuli]

I'm on the fence with Danny on my Epos ES 11s. I thought I had to replace them, BUT I got a used Copland CTA 405 tube amplifier to them (50w tube power). Now they sound amazing! These speakers have minimal crossovers. But maybe if I DO replace them, maybe go for a single driver speaker like Tannoy? I don't know.

[@dannyrichie9743]

If it were me, I'd go for an X-LS Encore. None of those production speakers will come close to touching them for the money.

[@amok281]

Tannoy are not single unit speakers, they have the tweeter within the mid/bass unit concentrically.

[@MrTeff999]

Question about No Rez. I see it’s about 2 inches thick, which reduces the internal dimensions of the box. Do you compensate by building a larger box?

[@dannyrichie9743]

No Rez is only 1" thick and it does not effect box volume. Any time you slow down the airflow it makes the box act as if it is larger. So the foam layer counteracts the air space taken up by the damper.

[@rodrigoraynor]

you can teache us to do better speakers, some content for who want to make theyr on speakers , like design and materials etc.thanks for share everything in here .

[@vegaslimoguy2376]

Are u new to the channel??? He already has several videos covering that.

[@pcorf]

7:10 I fixed up a pair of old speakers by using cheap drivers, Peerless woofer and Dayton tweeter and it sounded decent enough to me. So indeed you don't need expensive drivers.

[@eliseoquiroz8321]

When are the 8" releasing?

[@georgeswanson9483]

I'd been interested in this design, not everyone has the luxury of placing the speakers 3+ feet from the wall. It's a shame that there aren't more designs that give decent sound with close to wall placement.

[@dannyrichie9743]

Well, this one is not at all one that you would want to place close to a wall or corner. We do have some designs with that in mind though. All of our LGK models are good in that regard. The Studio Monitor works well with close wall placement. The Bully can be used in those applications too as it has a completely adjustable bottom end.

[@georgeswanson9483]

@@dannyrichie9743 Speaking of the Bully, I've been meaning to ask why The Bully has 95db or thereabouts efficiency on the passive MTM section whereas the standalone speaker with the same drivers seem to have a lower efficiency? Is that because the lows are rolled off for those drivers in The Bully? I'm asking because I'm interested in higher efficiency speakers for use with low powered tube amps and was interested in a TL design using those drivers.

[@nathandaniels4823]

@dannyrichie9743 with speakers that have large woofers in it like this, would it be advantageous to design a cabinet that has less width at the mid and/or tweeter? Like a pyramid or a pear shape? I ask because my (limited) experience with speakers sporting offset tweeters is that their soundstage seems very sensitive to minor head movements.

[@cbts0029]

a possibility is try a closed cabinet and use the wall as an enchancement for the low Frequencies, or use a cornerhorn.

[@xxxYYZxxx]

Klipsch Heresy is designed to go into the corner of a rectangular room, at least the original acoustic-suspension models.

[@leifharaldlongbeardiii861]

what do you think about the Devore Fidelity orangutan 0/96 and O/93 that's a 15k dollars speaker without bracing or any form of cabinet bracing only mdf and plywood. im building a exact replica of those with better bracing better crossover parts and design and im gonna no Rez the whole cabinet

[@dannyrichie9743]

Seeing that speaker makes me want to slap my forehead with the palm of my hand.

[@KarelKannel]

Do they have mdf and plywood glued together? Danny in Sonus Faber video told, that when glueing two materials with different characteristics, dampens a lot as resonance frequencies are different. Though missing bracing is still questionmark.

[@jonathandavis9507]

Their drivers are made custom so it won’t be “exact.”

[@leifharaldlongbeardiii861]

@@jonathandavis9507 yes they will I have an magnet mod and same phase plug I ordered from seas on the woofer, the morel is the same exact

[@leifharaldlongbeardiii861]

@@KarelKannel John specified that he used 2 mdf types and 1 front plywood im doing the same. but I will be bracing

[@naters83]

When measuring the tweeter without a network - it won't damage the tweeter sending low frequencies to it?

[@user-gf7kj5vj3p]

I'm sure he sets a safe starting frequency, REW you can do that, it's easy to forget though Good idea to have a run through check list.. but yeah if you send FR you'll blow them

[@dannyrichie9743]

Most tweeter easily handle the 1 watt test signal with no issues. The only ones we have to make an adjustment for are the true ribbons.

[@rosswarren436]

Never knew that (phase shift issues) about silver coated copper. Wow. Some companies make "jumper cables" to connect the terminals of bi-wire capable speakers for those who are not into biwiring and those cables are yep, silver coated copper. Maybe a small 4" length wouldn't do any harm, but why chance it? Good information.

[@joeygonzo]

Troels Gravesen kits!

[@matytinman]

Troels Gravesen 8008-CORNER SEAS T35C002 tweeter + JANTZEN JA-8008 HMQ mid-woofer

[@ywsx6489]

it looks like the 8008-CORNER.

[@craigenputtock]

@@ywsx6489 I wonder why the designer's measurements were so much flatter?

[@pandstar]

@@craigenputtock Danny explains that at about the 5:15 mark of the video.

[@jeanlephunk]

@@craigenputtock10db graph vs 5db danny used to

[@Nihil1st1347]

How bad does a phase shift caused by silver plated copper wire work out? In what frequency the phase shift happens?

[@dannyrichie9743]

It will take the sound of an acoustic guitar and shift the top end detail forward and away from the body of the guitar.

[@paulb4661]

​​@@dannyrichie9743 Oh Dear! Imagine what goes on at the AgSnO2 tipped relay, next to an energized solenoid! Oh no... what about the "phase divergence" on all those tinned copper PCB traces??? Computers will never work!

[@danielwoodard680]

@@paulb4661I look forward to following your channel.

[@toby9999]

​@@paulb4661Computers are digital.

[@RennieAsh]

​@@danielwoodard680no need, you only need to believe someone's words like you're already doing lol

[@GavinHodgson]

Wow

[@EskWIRED]

Can the dowels be attached just with wood glue? Do they have to be clamped when they're drying? Should they be attached with both glue and screws?

[@dannyrichie9743]

Just gluing them in with wood glue works fine.

[@nathanevans6277]

As the rear panel is only screwed on I'd take it off and glue 3/4" ply panels that connect front, back and sides together. These panels will require large cutouts for free air movement. I'd also add a baton or two across the top and bottom panels. This would involve more work but will be much more effective than dowels or thin strips. Keep up the great work Danny.

[@dannyrichie9743]

@@nathanevans6277 That's a good idea.

[@kft590]

If the speaker is built to Troels Gravesen's original specifications (drawings) the Speaker will sound wonderful if your measurements are wrong then and not built as planned then it won't be good just like a GR-Research kit not built to specifications.

[@dannyrichie9743]

Actually, as shown in the video, my measurements matched his very closely.

[@318ishonk]

The risk I see in building kit speakers is mainly about their tonality which you cannot test before buying and which depends on your room and equipment. In this case I'd have braced the cabinet and simply applied suitable DSP filters on my Wiim streamer. If I bought a crossover kit from Danny I still wouldn't know if I liked that tonality. That DSP approach does of course not work if the crossover or drivers have some fundamental flaws.

[@rothgartheviking858]

Great Video

[@RedSinter]

Well, the baffle edge reflection can be easily corrected adding an identical baffle face to remount the drivers then if handy he can round over the cabinets edge. And bracing is a no brainer.

[@D1N02]

I'd build a new cabinet the right way and add a super tweeter.

[@allankvist6741]

No reason for normal hearing. Plummeting above 15k is not degrading. Even undetectable for 90% of us. Try listen to a 15k sinusoidal tone. Extension above don't make the music sound better. You can probably hear a hi cut being flicked on or of, but 2 minutes later it sounds the same. Waste of money in my opinion, but your ears may be one of the few sets that will appreciate a supertweeter.

[@mojoneko8303]

I built a pair of your Criton 2TDX tower speakers with the superior crossovers a couple of years ago to pair with the Elekit 8600S 300B tube amplifier kit I built. I didn't use your MDF flat pack cabinets you sell for the kit but built the cabinets myself from 1 inch Red Oak and used 1 inch no rez on the inside back, sides and top of the cabinet. I also put 1/8 inch thick 3M asphalt sound deadening panels inside before installing the no rez. Is it possible to dampen a cabinet too much? They sound very good to me but these are the nicest speakers I've ever owned. I did a 3/4 inch round over on all the top and side outside edges and also the oval ports for the interior cabinet braces. Instead of using the subwoofer ports you sent I made my own out of 2 inch ABS black plastic pipe as I didn't want the plastic flange of the original ports showing. I cut out 2 inch port holes in the back of the cabinets 3/4 inch rounded them and cut a 1/4 inch deep recess on the insides to fit the abs port tube and made wooden brace's for the other end of the tubes inside the cabinet. I half rounded them as well. I sanded the outsides to 600 grit and finished them with 100% Tung oil. They look very nice and it took me almost two months to finish them. I am very happy with the way they turned out and how nice they sound. Thanks for making great speaker kits. 🙂

[@dannyrichie9743]

The Criton 2TDX is not one of our products. That one is from Creative Sound Solutions. However, we did design an upgrade for the 1TDX model of theirs.

[@mojoneko8303]

@@dannyrichie9743 oops my bad. I thought it was your kit but it's been a couple of years since I built them I should have checked. I did look at your speakers as well. I want to build a set of rear speakers as well . Thanks for the video! Do you think I over dampened them?

[@dannyrichie9743]

​@@mojoneko8303 Considering how lightly their cabinets are constructed, you could not have over damped them. If you build any of ours then you might want to put them up front and move the CSS models to the rear.

[@mabehall7667]

@@dannyrichie9743Looked for a video and/or upgrade kit for the 1Tdx on your web site and didn’t find one?

[@dannyrichie9743]

@@mabehall7667 We didn't make it publicly available.

[@tommyK7282]

I only use 12in high excursion woofers when I make my DIY speakers and I use 1in thick HDF for the whole cabinet. 6.5in midrange and a 2in soft dome tweeter.

[@paulb4661]

Why 2" ? With a 6.5" doped mid you can easily cross to a 1" tweeter at around 2.5/3k without beaming and loss of top octave as is the case with a 2", technically speaking, upper midrange driver.

[@DeclanHarris-vu4ib]

I have been a long-time follower and supporter of your work, Danny. I love your kits, and I appreciate your generosity and knowledge-sharing. However, I must express my disappointment with this video. I feel that you could have used a different speaker to demonstrate your points about inferior cabinet work and resonances. While it's true that the response is not perfect and the design work may not appeal to everyone, showcasing a customer's failed attempt at this particular kit to promote your own products seems incredibly unfair. For the record, I have built two Troels Gravesen kits, and I absolutely love them. Troels offers incredible support and is a really nice and humble person. Given the recent issues at Tekton, I would have expected that you, as part of this community, would understand that there is no tolerance for bullying and veiled defamatory behaviour. People can see through this stuff. I hope you will consider this feedback moving forward.

[@timothylovett6119]

Exactly what I was thinking. Thanks for having to courage to speak up on this one. We love you Danny... but this one feels a bit off.....

[@T-1616-ht1ls]

I couldn't agree more with this. Please consider the affect these videos have on people's reputation (and livelihoods for that matter!) - even more so when Troels is such a decent human being. All this video does is reflect poorly on GR-Research.

[@SkyeWilliams-jj8cg]

AGREE!!! I wonder how Troels Gravesen would feel watching this video... especially knowing that a customer has clearly not followed the kit plans. How about we show support for other players in the community? This reeks of unfair slander... i honestly would of expected more from you, Danny.

[@dannyrichie9743]

Guys, I did not mention the designer of this speaker. There was no slander. No mention of anyone... As usual, and even if it isn't popular, I am and will always be honest.

[@DeclanHarris-vu4ib]

@@dannyrichie9743 Not exactly the response I had hoped for. All the best, Danny.

[@ErnestLaRouche]

But how does it sound? I never heard his feedback on how any speaker actually sounds.

[@dannyrichie9743]

I am not a reviewer.

[@ErnestLaRouche]

@@dannyrichie9743 understood but you don't have to be a reviewer to give audio quality feedback of some kind based on changes

[@dannyrichie9743]

@@ErnestLaRouche We typically don't get in a pair of speakers. Only one is sent in. So we can't listen to a pair of them. In most cases, with these upgrades, we are just fixing audible problems. These could be amplitude related, stored energy, break up or ringing, phase issues, etc. So in all cases there will be clear improvements or we wouldn't be offering an upgrade.

[@ErnestLaRouche]

@@dannyrichie9743 okay but how can you upgrade one speaker and not the other

[@gralphirichmond2944]

It's a poorly build DIY cabinet. I would just build another cabinet and do it correctly (with bracing and no-res etc) rather than band aide the cabinet.

[@howardskeivys4184]

I note that in many of your videos and tear downs, you frequently refer to phase issues being a real problem to coherent sound reproduction. Yet, Floyd Toole, in many of his videos and printed material, clearly and authoritatively states that regardless of how well a room is treated, there will always be reflections. These reflections will guarantee that phase issues will be inaudible. Only with top notch, closed back headphones, will/maybe phase issues could be detected. Your comments would be welcome.

[@dannyrichie9743]

:-) How well the drivers are in phase and the effect of out of phase cancellations in the off axis responses are a big factor in what the room reflections will be.

[@howardskeivys4184]

@@dannyrichie9743 at 20C sound travels at 343 meters per second. So if the listener sits 4 meters away from the speaker the direct sound will reach him in 0.011 seconds. The reflected sound will be fractionally delayed and have less amplitude. There will be multiple reflections, all with their own delay and amplitude which the human auditory system has evolved to process and interpret. Are you sincerely suggesting that the minuscule timing smere of phase issues are going to be detectable to the human ear through that pea soup of reflected and direct sound?

[@dannyrichie9743]

@@howardskeivys4184 I like your question, by the way. Let's look at the one axis response first. When everything is in phase then the layering and positioning in the sound stage are more precise. Images and things in the sound stage have better depth between them. Instruments sound like real instruments and are not pulled apart from their highs to their lows. The off axis response also contributes to what we hear. For instance, if the drivers become very out of phase vertically or in the vertical plane, then the room reflections are uneven. You will have bright spots where the drivers are in phase and holes in the response where they are out of phase. So a floor and ceiling reflection doesn't match the on axis. So even if that reflection is delayed in time, you still hear it, and what you are hearing is a jumbled mess.

[@howardskeivys4184]

@@dannyrichie9743 yeh but, the issue for the end user/consumer, is whose opinion does he take as gospel? Your’s? Amir’s from Audio Science? Jean’s from Audioholics? Floyd Toole? Ask 101 experts the same question, likely you’ll get 102 conflicting opinions. You can’t all be right. So I’ve come to rely on the most reliable measuring equipment available to me, my auditory system. A classic example. I’ve built a system comprising of 2 pairs of speakers, vertically stacked. Each pair of speakers driven by separate power amps, controlled by 1 preamp. Every opinion suggested it wouldn’t work. There would be problems with cone filtering, phase anomaly’s, tonal suck out, Etc. But it does work, with non of those issues being audible. Plus you get a 7db SPL increase at any given volume and a huge dynamic headroom. Less cone excursion for any given, so lower distortion. But I’ve not found any experts that support my experience.

[@peterpida1840]

This here was perfect opportunity to show, how your No rez is working...

[@word2RG]

Be careful if you go hunting for Troels

[@noamgellerdiy]

Hmmm, seems like my comment got deleted. I'll try again Not all Troels Gravesen are equal- obviously. I have made 6 of his creation and regard him as very talented and a bliss for the DIY community.

[@CollectingRetro]

I find the 8008 Corner to be no exception. Sounds great if you follow the directions.

[@kennethabbott3856]

Danny: hope you guys are okay. I saw that there were tornadoes in your area last night.

[@dannyrichie9743]

They were in my area, but 30 to 40 miles away. Thanks for thinking about me though.

[@jasonme3557]

The cabinet is brutally ugly. I would keep the decent parts and start with a new cabinet.

[@mfr58]

It is probably a poor attempt at a live cabinet design, that is a legitimate way of tuning speaker sound. It's a different approach to the attempts at creating "dead" cabinets. Although I know you won't accept this method of speaker design there are successful examples of such, including the Spendor BC1.

[@dannyrichie9743]

That is tuning is adding coloration.

[@seanb3303]

That method is to lower the frequency of the box resonances… which can be an acceptable trade off for a budget build.

[@seanb3303]

I wonder if mass loading the top panel would help

[@dannyrichie9743]

@@seanb3303 Mass always helps.

[@nathanevans6277]

​@@seanb3303it's much better to try to push cabinet resonances as high in frequency as possible. This has several advantages. There will be fewer harmonics of the fundamental within the audio band. The amplitude of any cabinet flexing will be lower. Higher frequencies are easier to damp than low frequencies. Purposefully building a cabinet to resonate is not a good idea and is very likely to result in a very fatigueing sound.

[@donquixote4630]

So a very good designer makes a kit including very good drivers and specific cabinet instructions. Somebody buys the kit and builds the cabinet ignoring the design and doing a rookie job and the "issue" is the design ??? I will rather buy Troels Gravesen kit since I trust him more, and I agree with his excellent driver choice, and superlative cabinet design - but, I will choose to go active with Trinnov and fly over the "cuckoo nest" of the passive crossover that is simply non-sense nowadays.

[@dannyrichie9743]

The complaint from the builder, and the guy that bought it finished, was that they sounded dull. This was due to the rolled off top end and tweeter level that was down several db below the woofer level. This was as designed and built according to plans. The cabinet resonances were a secondary issue. Even if built to specs the cabinet design is lightly braced and is still a problem.

[@chuckmaddison2924]

I gave up building speakers. Building amplifier's is considerably easier.

[@jungtarcph]

Danny - your arrogance and way of criticizing and bullying without backing up your claims with facts is an unfortunate trend in 🇺🇸

[@dannyrichie9743]

Don't mistake my experience and wisdom for arrogance. The truth is that I am fairly humble and I try to be as tactful as possible when giving any evaluation. I can also easily back up anything that I say.

[@rikardekvall3433]

Didn’t you watch and listen to Danny? Feel sad for you if you get offended by the facts in this video.

[@MrTeff999]

The criticism was of the box, which was built by an unknown DIYer. There’s no need for anyone to be offended. I’ve watched quite a few hours of Danny’s videos and I’ve always found his critiques to be helpful and fair. He’s a teacher.

[@MrTeff999]

Question about No Rez. It’s about 2” thick, which reduces the internal dimensions of the box. Do you need to compensate by building a larger box?

[@dannyrichie9743]

@@MrTeff999 No Rez is only 1" thick and it does not effect box volume. Any time you slow down the airflow it makes the box act as if it is larger. So the foam layer counteracts the air space taken up by the damper.

[@frankd.b.9233]

A bass should be 8 inches max, why... too much space in the woofer makes it difficult to control the bending of the material from center to bass edge [ such as cardboard ] with a good mid and a tweeter, that's my opinion. a good speaker the size of the cabinet and insulation is certainly also important, when they are ready let me know lol;l

[@anthonyjackson7097]

Troels Graveson definitely knows audio speakers. But, lets not be too hard on his designs. Especially when someone builds the kit incorrectly. John Krutke he extensively tested comercialy available drivers and found their weak points and posted for the DIY world to use . I believe a person considering buying a speaker kit should reserch the parts used before making the purchase. All the speakers drivers from reputable manufacturers post the T.S parameters. From those parameters it will atleast give you a clue to if the designer is using the driver within its capabilities.

[@dannyrichie9743]

My measurements showing the output imbalance did match his....

[@anthonyjackson7097]

@@dannyrichie9743 Sure, I understood that point.