Thanks again Tom. I really appreciate all the effort you put in to teaching us your techniques and line of thinking when working on your projects. It's very informative and helpful.

@zarboaudioprojects1430

2 жыл бұрын

Thanks for that... I appreciate the appreciation! I know it went a smidge long, but hopefully it flows well enough so nobody will fall asleep watching it.

Great job Tom! Thanks for the great video.

@zarboaudioprojects1430

2 жыл бұрын

Thank you. I love sharing about how we can have fun doing this stuff!

You could try Tungsten or Lead washers for the PR's, more mass with less height...

Very cool!

@zarboaudioprojects1430

2 жыл бұрын

Thanks!

And never forget the always important SAF, spousal approval factor.

@zarboaudioprojects1430

Жыл бұрын

True. My wife has put up with a LOT of larger sized speakers/subs over the years.

What's it like properly corner loaded like where your other sub is. With one I'll usually try and corner load at the front ideally opposite the room opening, so there's less chance of corner to corner standing wave.

@zarboaudioprojects1430

2 ай бұрын

It really shines in the corner of my room. Like you said, rooms do affect the bass response, but the corner of my particular room helps boost the low stuff really well with no noticeable nulls. It's a fun little sub project... sounds like a basic 10 from 5 to 7 years ago.

FYI. If you do choose to run one coil, you can short the other and the TS parameters will remain the same. Having the second coil shorted makes it appear as though it's connected to a low impedance amp, just like it would be were it wired in parallel. Perhaps lead or brass washers?

@zarboaudioprojects1430

2 жыл бұрын

When you say 'short' the other coil, do you mean just run (+) and (-) lines from the amp to ONLY 'coil one,' and then connect the (+) and (-) leads of 'coil two' together? If so, I can't see how some specs won't change, but I could put it on the DATS to see what that change makes. About the washers, I considered using a heavier metal for the washers, but felt that I needed to use readily available materials as I was pretty sure this design would end up being duplicated. Since I went down from 120 to 100 grams, I think the weight is just close enough to the center to be 'okay' for the most part as it relates to longevity. Possibly in a few years the PR's could be rotated if sag becomes an issue. Thanks for commenting!

@t00by00zer

2 жыл бұрын

@@zarboaudioprojects1430 Yup, just jumper the two unused leads. The Qts and Vas should remain unchanged or very close. Of course, you only get about half the power handling.

@TimpBizkit

2 ай бұрын

I'm thinking that will just choke the output. If you really want to drive it hard, use a 2 channel amp and put one coil on each channel. Most amps are happy at 4 ohms per channel. For optimum results, make sure the signal to each coil is the same amplitude and phase - e.g. that independent level controls are the same, or the balance control is centred.

Hi Tom. Is it possible to use this woofer in 2way bookshelf? Do you have any measurements?

@zarboaudioprojects1430

2 жыл бұрын

Yes, I would say that this would be a perfect candidate for a bookshelf-type speaker. It has a fairly flat response out to about 4k. You should be able to use it with most decent tweeters I would think. Check out the FR graphs here: www.parts-express.com/pedocs/specs/295-102--epique-e150he-44-spec-sheet.pdf

@valuerc2664

2 жыл бұрын

@@zarboaudioprojects1430 what tweeter would you use that can match nicely and not over 70$?

How do you think just one of these would perform in a .2cuft sealed box? I have an old pickup that im trying to build some fiberglass boxes in the B pillers. Not looking for crazy amounts of bass just a little to help the 4.5 coaxials in the dash. Great video!

@zarboaudioprojects1430

2 ай бұрын

I have not modeled an enclosure that small, but my guess is that you'd get boomy 80 to 100 hz, and very little under 50 hz. It could be DSP'd a bit, but I think there are probably better options, especially given its relatively HUGE magnet structure. If I get a chance, I'll model it and reply back.

@davidh3545

2 ай бұрын

@@zarboaudioprojects1430 I'd appreciate it if you have time. I wonder if a port would be better but from what I've read the port needs to be rather long. Thanks again for the help and posting the video.

@zarboaudioprojects1430

Ай бұрын

@@davidh3545 Well, in a .2 cu. ft sealed enclosure, you have an F3 of 70 Hz, and an F6 of 54 Hz. Not too good in my opinion. Cabin gain will help some, and you can DSP it a bit... but I would shoot for high 40's as a response, not 70 hz. An alternate... have you seen Paul Carmody's Voxel subwoofer? It's vented and only a little bigger than your proposed box size, check this out: techtalk.parts-express.com/forum/tech-talk-forum/58008-voxel-a-mini-sub

@davidh3545

Ай бұрын

@@zarboaudioprojects1430 thanks for taking the time to check that for me. I'll check out that link. I downloaded winisd but I honestly don't know how to interpret the graph lol. In the past, 20 years ago, I just built sealed boxes for a Polk sub, it was loud or at least I thought so. I'll have to find some videos on how to understand this graph and I need to build my box out of fiberglass so I can calculate my exact size. Right now it's a rough calculation. The box will only have 1 flat surface. Again thank for the reply and posting these videos!

At 26:18 F3 = 39 Hz

Been watching alot of your builds, excellent work..! I've been into audio since high school. Anyhoot my shop is almost complete and getting ready to build speakers... Curious as to where you buy all your different veneers from..?

@zarboaudioprojects1430

Жыл бұрын

Thank you! I buy most of my veneer from VeneerSupplies.com and lately some of it even came from Aliexpress. I think the veneer for the Epique small cube subwoofer came from Ali.

@houseoffire72

Жыл бұрын

@@zarboaudioprojects1430 Thank you for the help very much appreciated.

Why not use the Epique 5.5” passive radiators?

@zarboaudioprojects1430

23 күн бұрын

The 5.5" PRs were not out yet when I dreamed this up, but truthfully, they wouldn't dig as low as these larger PRs do, at least not in this small of a box. Thanks for watching and for the comment!

@andrewmcmillan8110

21 күн бұрын

@@zarboaudioprojects1430 makes sense. I have a 5.5” epique in a .35 ft^3 ported box tuned to 43hz in my car and it sounds amazing. I was so impressed with it that I modeled it with the epique passives for a small home theater sub and I wasn’t too happy with its output. I modeled your build and it’s much better with the passives you chose. Very impressive!

🙋👍❤️

Such a great video! Your descriptions and explanations sounded perfect to me - it drives me nuts when an otherwise well-produced video gets the details wrong, but you were hitting all the right details at the right time. I'll disagree with you forever on the pronunciation of "radiator". Every time you said it I was thinking back to my youth ... "Dude, that' sub is so RAD!" Repeat after me - "RAY dee ate or". Or just carry on - your work is truly rad! I saw in your PE post you tried powering this with a DTA2.1 with coils wired series for 8 ohms and didn't get satisfactory output. I know you've got an early version. Does it use the TPA3116 chip from TI like the latest DTA2.1BT2? Because that TPA3116 chip is widely misunderstood when it comes to its power output and impedance driving ability. Most people think configuring two amp channels to drive mono means "bridging" and that was generally true for a long time. But not so with many chip amps including this one. It turns out that in stereo mode the TPA3116 is already running in a Bridge-Tied-Load (BTL) configuration. That means each TPA3116 chip technically has 2 pairs (4 total) of single ended channels bridged together just to produce stereo output. Then if you configure it for mono, you're putting those 2 stereo channels in parallel. It's called PBTL in the datasheet for "Parallel Bridge Tied Load". The result is that you don't actually get any more voltage by configuring mono because you're just tying the two plus outputs together and the two minus outputs together. And you don't get any more power either ... if you use the same impedance load. So what do you get? You get twice the current driving capability. You can drive a lower impedance load. TI rates that chip as 50 watts at 4 ohms stereo or 100 watts at 2 ohms mono. The DTA2.1BT2 uses two of these amp chips with one configured stereo and one configured mono for the sub. I'm running the mono sub output at 4 ohms for my DIY sub (Dayton DVC 8 inch sub with dual 8 ohm coils in parallel) so I only get 50 watts max. Same as if I ran one of the stereo channels to a 4 ohm speaker. Because, stereo or mono mode, you're running the same voltage. In your case you were running mono channel into an 8 ohm load (the two coils in series) so that poor chip was limited to only about 33 watts (based on figure 13 of the datasheet) before it ran out of voltage headroom. But you weren't anywhere near the current driving limit of the chip. I think you could have run the coils in parallel (2 ohms) and gotten the full 100 watts (or more according to figure 22) that TI intended. Unless your older design DTA2.1 uses a different chip. Dayton rates the DTA2.1BT2 as 2 x 50watts + 100 watts but they also only say the impedance load should be 4 to 8 ohms. That doesn't jive with the TI datasheet. Either this amp can push a 2 ohm load on the sub output or it's not really 100 watts. Plenty of folks will be quick to say "Of course it's not 100 watts! Do you really believe any amp specs? Besides that 4A 24V power supply won't support 200 watts anyway." Fair enough, but I do believe TI knows how to write a datasheet.

@zarboaudioprojects1430

2 жыл бұрын

Thanks for the comment Ryan. I can't argue with you on the pronunciation of 'radiator' a wood stove doesn't RAD-iate heat... it 'RAY-diates heat. But I'm still going to say it that way because it's too hard to train myself to say it right. :) I have several versions of the DTA2.1BT amp, one I modded for a lower crossover frequency, the other one is the newer version with the crossover knob on the front. I figure the sub section is doing maybe 70 clean watts at 4 ohms given the included power supply. At 8 ohms it's closer to 50. This sub just needs a LOT more than that to get moving. I didn't think to run the coils in parallel for 2 ohms, it may have had somewhat decent output that way, but I have concerns using it down to 2 ohms and pushing it hard. It may survive, but there could be issues. I mentioned the DTA2.1 amp just as a reference for how much output it would produce with it since I figure some folks may try to pair them up... I don't think it would work. The amp I'm using with it outputs probably close to 180 clean watts (at 4 ohms) and maybe 100 at 8 ohms and I can basically push it to it's max or close enough. Yeah, TI's data sheets are accurate, I'm sure... It's possible that they give the wattage rating figures they do because of the limited amperage power supply that ships with it. Thanks for watching and for the comment. I'm glad you liked the longer look at the build. I like that type of stuff myself, but not many others do.

@ryanschnacke6719

2 жыл бұрын

@@zarboaudioprojects1430 Yeah, I understand about being wary of 2 ohms. We've been trained over the years to think mono = bridged = poor impedance handling. But many of these chip amps do mono mode as parallel instead of bridged and it has the opposite effect compared to what you'd expect. If you're comfortable running 4 ohms on the stereo outputs (BTL) then that's just as tough on the chip as running 2 ohms on the mono sub output (PBTL). Should work fine unless Dayton did something wonky in the application circuit. Maybe I'll try it out on the DTA2.1BT2 just to prove it. I've got some old Ascendant Audio Atlas 15 inch woofers that actually have DVC with one coil 4 ohms and the other 2 ohms. Crazy eh? They were intended for you to tune the Q of the woofer by driving the 4 ohm coil and then the 2 ohm coil you could short (low-Q), leave open (high-Q) or use a resistor to achieve mid-Q. I bought them to do an infinite baffle subwoofer in my attic so high-Q was perfect. I took them with me when I moved. Now I use one in a sealed box with both coils driven in series (low-Q, 6 ohms) in my living room. If the amp you're using is the Nobsound G2 PRO then it uses the TPA3255 chip, also from TI. That datasheet shows mono PBTL output into 4 ohms is about 120 watts at 32V supply and 1% THD (figure 23). As expected, this is virtually identical to the output it would send to each of 2 channels if it were wired up as BTL 2-channel mode (see figure 8). And from that same figure 8 we can see it would do about 60 watts into 8 ohms. That 8 ohms power output will hold true for BTL 2-channel mode or PBTL mono mode. So you're working with less power than you think. But we're talking just a couple or three dB difference. If you dared to try the Nobsound at 2 ohms, the chip should be good for about 220 watts but the power supply not so much. And again it's another case of an amplifier that ought to be rated down to 2 ohms, especially given the claimed power output, but mysteriously the maker specs 4 ohm minimum. And just to guarantee confusion they put a switch on the front labelled "PBTLSUB" that has nothing at all to do with configuring the chip into or out of PBTL mode. Sigh. I'm probably boring you with this amp stuff, but wanted to let you know these chip amps might have a bit more to give if you let them stretch their legs with a lower impedance.

@ryanschnacke6719

2 жыл бұрын

I tried the DTA2.1BT at 2 ohms today. Used that crazy Atlas woofer in free air. The DTA drove the 2 ohm coil (1.7 ohms DC) fine for several songs as I slowly pushed the sub level knob higher and higher ... eventually to max. Then I pushed my phone's bluetooth volume eventually to max. This with the DTA's main volume knob at my normal level - about 1/3. During an especially bassy Taylor Swift song (make fun of me if you must) it seemed to go into protection mode because the mono sub channel suddenly dropped in volume. Not completely, but reduced by a lot. The other chip for the stereo channels kept going unchanged. That fault setting stuck even when I switched to my normal 4 ohm subwoofer (sub level down to 0 during the switch and then back up but still reduced sub output). When I power cycled the DTA, it returned to normal operation with my normal settings. So I'm guessing I tripped the fault on the chip that runs the sub and apparently it's not configured to auto-reset. I was keeping a hand on the DTA case to feel for heat. It got warm but not unusually warm. Still could have been the over-temperature fault locally on that one chip ... or the over-current fault on that chip. At any rate, I was pushing a lot at that time. Sub level all the way up. I'd have feared for my little Dayton DVC 8 sub at that level. The 15 inch woofer that I was driving was moving nicely. Not a ton, but respectable considering I was only driving 1/3 of the total voice coil so it's sensitivity must have been terrible (what a crazy woofer). The bass would have been LOUD if it had been in an enclosure. The voice coils on that 15 are rated for 450W total, 300W on the 4 ohm coil and 150W on the 2 ohm coil. So not much risk I'd burn the coil, but you never know. Altogether I'd say this confirmed for me that the chip really is designed for 2 ohm operation but the DTA amp as a whole might not have the greatest heat sinking. The fact that the case didn't get hot seems an indication that the case is not a sink, so the heat gets trapped inside. Plus there's the issue of the limited power supply. Probably best to think of it as 25W x 2 @ 8 ohms + 50W x 1 @ 4 ohms. Then the power supply makes sense and the heat sinking probably won't bite you. I posted to PE about one of their TPA3116 mono boards and I'll be interested to hear their response. If you're into amp reviews, I like the videos from Williston Audio Labs. He reviewed a $10 chip amp board that used a TPA3116 in mono mode. On his amp dyno that board hit 32W at 8 ohms, 56W at 4 ohms, 89 watts at 2 ohms. All pretty close to the datasheet predictions except falling off a little at 2 ohms. Granted he was using a stiff 25.3V supply (2 car batteries). And then it survived 1.6 ohms in a burst test to output 106W. Not bad!

@zarboaudioprojects1430

2 жыл бұрын

@@ryanschnacke6719 Ryan, not boring AT ALL! and this is frankly the perfect place to discuss it. I have investigated this stuff quite a bit as well, and I've found that sometimes the chip ratings and actual physical amp ratings are not always in line. I go with the amp ratings in that case as long as it's a fairly well-known company, especially one like Dayton Audio. They also may just want to keep the likelihood of amp failure to a minimum so they don't recommend 2 ohm loads as they will be harder on the amp. Dayton does warranty these things for a full 5 years after all. Yeah, I chuckled at the PBTL switch on the front... its a 'sub or full-range' switch only as far as I know. Thanks for the comment and for the good information. It will likely help others, so thank you!

@ryanschnacke6719

2 жыл бұрын

@@zarboaudioprojects1430 I do love me some Parts Express/Dayton! I've had to use that warranty on occasion, so I do appreciate that as well. I'd be happy to follow the amp ratings if they made sense. But claiming 100W on the sub channel while limiting the load to >=4 ohms is cheating. And as much as I love 'em, Dayton Audio does not get a pass on this. It's either ignorance or willful deception. Chevrolet claims the Corvette makes 490hp (@6450 rpm). Now imagine the uproar that would happen if they set the redline at 4000 rpm ... without derating the hp output. That's the equivalent of what's going on here. Undersized power supplies are also a frustration but at least the majority of the customer base has some awareness that a 24V x 4A power supply can't possibly yield 200W continuously. The impedance rating issue, on the other hand, is so much more subtle - you've got to dig into chip datasheets to understand what you're really getting. Sorry for the rant and I'll hop off my soapbox now. Thanks for letting me bend your ear!

No X-Over?

@zarboaudioprojects1430

5 ай бұрын

The crossover is handled by the amplifier, which is the norm on most subwoofer amplifiers.

I’d like to hire you to consult on a build for me. I can’t get your contact page to work on your site. How can I reach you?

@zarboaudioprojects1430

2 жыл бұрын

Hey Brent, I appreciate the interest, but I'm slowing down with content, and I"m not sure if I'm going to continue with the YT thing at this point. I'm behind on a bunch of stuff and wouldn't want to commit to something I can't deliver on.

Using Lead instead of washers would've been better.

@zarboaudioprojects1430

5 ай бұрын

You're the second person to suggest a heavier washer material. The thought never occurred to me. Good thinking. Thanks for watching, and for the comment.

All this effort and the epique isn’t even suited for a passive radiator enclosure. It only works best in a vented

@zarboaudioprojects1430

2 жыл бұрын

Nick, a 'Passive Radiator' system is very similar to a 'Vented' system, and they often model similarly, and have very similar frequency response graphs when implemented correctly. The truth is, this Epique driver "Works" amazingly well in this dual 8" Passive Radiator system.

@kennethfarquhar8518

Жыл бұрын

Shush.you do what you want and we will follow in Tom's foot steps okay? Great work Tom