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- DrewsBrews 3:10AM
- Eggguy 3:10AM
- jholtz 3:10AM
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- Tom_S 3:10AM
Dayton RSS210HO-8 or SB Acoustics SB23MFFCL45-8
So, building my first build. I am doing a 3-way with active crossover and DSP sigma studio support (so autoEQ will be used).
I am planning on using the following drivers and tweeters:
1) Peerless DA25TX00-08 (tweeter)
2) SEAS Prestige U18RNX (driver)
3) SB Acoustics SB23MFCL45-8
I am open to any 6.5-10" sub (although I prefer 8" and smaller) that is 8 Ohm (to match the selected amp). I am looking for low distortion. I just switched to the SB sub over the Dayton RSS210HO-8, but could be persuaded to use the dayton (switched because likely less distortion). I really want to keep the sub to around $150, but could push it to higher if needed (just not $300 a pop, otherwise I'd be using the $280 or $290 SEAS sub).
I plan on using the WONDOM JAB5 amplifier in a 2x100W and 1x200W bridged configuration. This also will allow for programming the filters per channel, accounting for phase and timing, and using the EQ to further flatten what should be an already flat response.
I'm open to any and all critiques and comments.
Comments
Since this is your first build, keep in mind that a flat response may not be what you need, because what's happening off axis is just as important as the on axis, they have to work together for lack of a better description. I personally believe that to make a sub choice between the two will be enclosure dependent. Both are good drivers.
Agreed. I have been trying to find out as much information as I could and compared the requirements for space. Further, I have been trying to find more information on the distortion and selecting the woofer and tweeter, in part, on the off-axis performance and looking for tweeters that can for sure cross before the 60-degree axis goes off on the U18RNX.
This is why I am also considering SEAS Prestige Titan 27TAC/GB as the tweeter, that way to cross low, but still have decent off-axis performance, both at 30 and 60 degrees, while also having low distortion and an ability to get loud.
So, I think I will stick with the SB, then the SEAS driver and tweeter. This should have great off-axis response throughout.
If you want the Titan, I've already simmed this MT. Tweaking might be necessary, but the need for a 3-way might be moot with this in play.
InDIYana Event Website
Truly phenomenal there. I do wonder, though, how well the U18RNX-P would do playing that low (meaning distortion wise). That is, in part, why I sought out the 3-way, to have a low distortion sub that can hit down to F3 35Hz (mainly for the music side of things).
What program are you using? I'm still using WinISD.
Also, I saw a video on audio judgement where he used the CA18RNX. He solved the problem with the drop around 700Hz by stuffing the floorstanding speakers he made with fill to address a standing wave issue. Similarly, on a different forum, a person that lent their U18RNX to be tested (maybe even to you) mentioned that they didn't see the same drop in their box when implemented (Parts-Express forum maybe; I've joined a couple recently). In any case, the bump there may be able to be addressed with box construction and deployment.
Now you have me wondering if the sub is needed to play the lows there and possibly have less slide downwards from the 200 to 50Hz range (because that response looks really nice).
This is the spec sheet on the sub I was considering. I was told the same guy that designed the Scan-speak 22W/8851T designed those woofers, so figured it might be worth giving a look. Have that pull the low end, followed by the U18RNX taking over and being in a sealed compartment.
But you really have me thinking hard about this one now...
The software to model bass response Wolf is using is called Unibox and works under Excel. It's old, but works very well. I use WinISD as well, but port modeling in WinISD is hit or miss. For the crossover side, the software is PCD. Very capable, known performance.
Why prefer am 8" woofer in the three way? You mentioned loud, and in that case a 10" woofer can work magic (IME). Box size gets larger of course.
In part, cost to quality. In part, I'm not trying to go floor standing (trying to stay around 30" tall or less, but am open to full floorstanding if the need arises).
If I had an extra $130 per sub, I would definitely go 10".
So, mix of considerations. If you could recommend a good sub under $160 that is a 10", with low distortion, I'd be open to it. I'm also trying to not go too wide on the front baffle over the U18RNX-P, but could always side mount if I keep the crossover low enough so it isn't directional.
Another consideration is the amp I chose:
Wondom JAB5
https://store.sure-electronics.com/product/756
That is not for the bluetooth. It is because it has an ADAU1701 DSP chip built in. That means I can bridge two channels to run 200W, then use SigmaStudio to create the crossover, followed by using REW measurements, convert it to a linear phase FIR filter, then apply that correction to the speaker. Downsides to the amp: 1) it is 6 Ohms per channel (part of the reason I chose all 8 Ohm components, if you didn't notice), 2) it will only be able to handle the speakers up to about their RMS, above that, it's current protections should shut it down.
I'm sure many may prefer the passive crossover, but being my first build, and my comfort with computer generated dsp over reading schematics or electrical circuit design, I feel I can move onto that with a later project.
Now, of course I could always switch it to a 2.1 channel board (2x200 and 1x400W; https://www.parts-express.com/pedocs/manuals/320-3350--sure-aa-ab33312-manual.pdf (3Ohm)), then buy the DSPB-K (https://www.parts-express.com/Dayton-Audio-DSPB-K-DSP-Kernel-Board-and-DSPB-KE-Kernel-DSP-Expansion-2-In-3-Out-325-1300 ), which would allow for accomplishing the same per channel active crossover and the same support for 8Ohm speakers, but also allow for supporting 4 Ohm speakers as well, but I haven't fully decided until I place my order.
I'm trying to keep the drivers balanced on sensitivity, while shooting for 101-105dB, with anything else being a bonus, while also having really flat response, great off axis sound stage, and low distortion. I've already eaten up a fair amount of my budget wiggle room with the U18RNX-P and the Titans.
I'm building 4 speakers (2 pairs). One pair is going to my parents, I keep the other pair. I have a DATS v3 and a miniDSP UMIK-1 calibrated by Cross-Spectrum Labs for my test equipment. Need to add an SPL meter in there. Also need to buy some tools for the woodworking that I do not already have.
So, because I'm trying to have a fully flat response, I don't have to go too ham on getting a high SPL sub. Just something that has low distortion and can match sensitivity of the other two drivers at RMS. Or at least that is my thoughts.
The man who designed that 22W is no longer with us, and I'm afraid did not design for SB, tmk. I've had some peers not like those SB woofers, and could not get them to perform satisfactorily.
InDIYana Event Website
Thank you. Then I was informed incorrectly. It is also good to know that these are not performing satisfactorily as well.
Then could I ask you what you would recommend for a sub in the 8 or 10 inch realm with satisfactory performance?
For example, how is the CSS 10"?
Maybe giving some options is the better way to ask:
CSS SDX10 XBL2 (have to save up longer, don't like the distortion shown in AudioXpress here: https://audioxpress.com/article/test-bench-the-sdx10-home-audio-woofer-from-css-audio; but still considered a decent sub)
Peerless by Tymphany 830452 10" XLS Subwoofer
Peerless by Tymphany XXLS-P835016
Dayton Audio RSS265HO-44
Dayton Audio UM10-22 (would have to switch to the 2x200 and 1x400W amp)
Dayton Audio MX12-22
Dayton Audio RSS315HO-4
You may want to look at other DSPs if you are really sold on FIR filters and linear phase. The ADAU1701 can't support enough taps for most FIR filters, but is well suited for IIR filters.
I am not overly attached on the FIR filters and linear phase. I do intend to try multiple methods after getting to that point. But if I may ask, which other chips are better for FIR filters? The ADAU1467?
I am still a young padawan, so I know enough to know I have much more to learn. Please enlighten me as to alternatives that can be used for these purposes.
Neil Davis used to be pretty active on the Parts Express board, and he knows all about chips and dsp. IIRC, he claimed that the ADAU1701 had plenty of "horsepower", but that most implementations were only using a fraction of it's capabilities. He's got a web site that might be of interest to you.
http://www.audiodevelopers.com/6-adau1701-based-stereo-3-way-dsp-board/
I stumbled upon that site a day or two ago. This is what I found telling on the ADAU1701:
"This board is called the ESP-DSP, but I’ve also toyed with names such as “Last Gasp”, “ADAU1701_exit” and some others that convey an ending of the ADAU1701 as the go-to DSP. It’s still a potent device for speaker-building, as it does a great job with active crossovers, BSC, EQ, delay and even bass enhancement for small woofers. But there are some new challenges for line arrays and more sophisticated bass management and more complex digital processing where the additional speed and precision of a more capable DSP is needed, so it’s time to move on.
This final ADAU1701 design will be the platform I’ll use to get the software in better shape and hopefully at a point where it can be distributed publicly. Up to now, the code has undergone revisions for every iteration described in these pages, and that constant change is not conducive to good code design. The software is in need of reorganization and refactoring, and this simple board will be a great opportunity to “finalize” the code."
Because of this, I took a look at the other chips by Analog and saw the ADAU1467, which had much faster processing, more storage, etc., but unfortunately there were a couple drawbacks to it, although I cannot remember them off the top of my head.
That does not mean this is not a very robust and powerful chip/platform. That, in part, is why I chose it. But I will reach out to him to find out more. Thank you for pointing me in that direction (couldn't find that page after I had closed it).
I hope he is doing ok, been awhile since I saw anything from him.
He posted on diyaudio not too long ago.
OK, good. I don't get over there very often.
The JAB boards you are considering ... is the output power as overrated as the other wondom boards?
Yes. They show 6 Ohm when you use it 8 Ohm and cut off a good portion of usable wattage. Although the specific one I selected is designed for 36V power supplies instead of their normal 24V, which supports the 4 channels (or three channels with 1 bridged or 2 channels with both bridged). One thing they did do is get it so you could connect two of the amp boards together for the JAB5.
I am also considering doing it piecemeal with one of these boards supporting a separate amplifier, instead of it all being integrated:
https://ebay.to/3efLcJW
Going with that (so $200 for those boards, plus the other modules and the amps per speaker across 4 speakers) would possibly open things up, including DLNA over a home network, and more advanced FIR filtering.
I do know Sure (Wondom) is putting out their new programming boards soon (ICP5). It will be $25. I wonder if it will support the ADAU1466 and 1467 chips.
@jr@mac - Neil Davis's last posts on that link (or at least that I have found exploring the site so far) was march, talking about an amp. http://www.audiodevelopers.com/2021/02/15/february-16-2021/#comment-4067
I found out the 1467 has USBi, so with drivers, should connect to a windows computer.
https://www.aliexpress.com/item/1005002162173435.html?algo_pvid=e6ef3135-7877-4dd9-97ab-e210e31da084&algo_expid=e6ef3135-7877-4dd9-97ab-e210e31da084-0&btsid=0bb0624116189670598485282e20f3&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_
That is the core board for $45 plus shipping. Unfortunately, the full development board, which includes the ADAU1977/AD1933 codec costs closer to $175.
https://www.aliexpress.com/item/4001197235055.html?algo_pvid=b7df99b3-24fb-472a-9b23-be338b78c6ac&algo_expid=b7df99b3-24fb-472a-9b23-be338b78c6ac-12&btsid=0b0a556516189588741468831ee02c&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_
If anyone knows of a better DSP that wouldn't run $700 to run them as an active crossover, let me know (and that is excluding amp cost on top of it).
Otherwise, the $30 or so power supply with the JAB5 for $70 looks like a decent deal, at least until the ADAU1467 has been further developed and the price comes down. It is not even listed yet on the list of supported SigmaStudio chips:
https://wiki.analog.com/resources/tools-software/sigmastudio/supportedic (last updated March 17, 2021)
The ADAU1466 Dev Boards I saw cost as much or more than the ADAU1467, so better to grab the latter.
What I will likely do is spend the $400 to get the speakers going, then down the road swap out the DSP and amps.
Does anyone know of a better DSP ASIC at a reasonable price?
There are a few TI PurePath amplifiers that take digital in and do full DSP before the amplifier stage. Have you looked at them?
I have not. Do you have any links to a few products incorporating TI purepath?
I was hoping you had, because I haven't seen anyone implement them yet. I don't think I'm good enough to design the PCB for these yet, I'm just learning now.
Like this one here: https://ti.com/product/TAS3251
Zoudio has a nice 4-channel amp based on the TAS5825M PurePath chip. It's lower power, but could be a nice introduction.
https://zoudio.com/product/aio4ch/
Since PurePath products are from TI they don't support SigmaStudio. The developer created his own filter UI for the amplifier, much like MiniDSP created their own filter UI for the ADAU1701.
Although it is too low powered for this project (as is possibly the JAB5 if I stuck with an 8Ohm sub, as bridging is marked as reducing the resistance in half, so 8Ohm on a 3Ohm 200W line would run closer to 66W, whereas it would be closer to 134 or 144W for the 4Ohm sub), I may just have to buy the sub separate and have it like the dayton/wondom kernel board and extension board.
Do you know if they have any of these TI chips in a configuration like that? https://store.sure-electronics.com/product/AA-AP23122 https://store.sure-electronics.com/product/AA-AA11428
Although having it integrated with an amp is nice, I really don't mind having to run separate cards if it is needed.
Either way, because I didn't have the sub figured out, I only ordered the SEAS U18RNX-P and Titan so far. So still open on the sub and the amp/dsp equipment (which then dictates the power supply). Also will give me time to play with them and make some judgments with how low the U18RNX-P can go and what I see first hand. (No offense, although I can learn a lot from other's experience and collected data, I still like to see it for myself, kick the tires, so to speak).
Edit: I forgot to mention that the TI amp may be something I consider when I get around to doing a 5.1 system for my living room.
Edit 2: also please correct me if I am miscalculating the drop in watts when switching between Ohms values.
So, update on components:
500W 36V power supply
Sure JAB5 amplifier x4
4x SEAS 27TAC/Gb
4x SEAS U18s
4x MX12-22
The MX12 can fit in the size box for a 10", while hitting down in the 20Hz range. Generally, 12" subs will distort a bit less at low frequencies than their smaller counterparts. And the MX12 does this in 2.17ft^3, meaning that the overall size of the speaker will be moderate (2.5-3').
Going to also put an inline fuse in for the final design. I might go waffle steel on the subs with cloth on the top part. Still trying to decide. I plan on a double or triple baffle, so the waffle is to set it apart, then an angle cut to reduce it to a single or double baffle for the U18 and possibly again for the Titan. After I check timing alignment, that will finalize part of that. I do plan to flush mount.
And I was convinced to swap out the RSS315HO-4 for the MX12-22