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Since I am parking my little SB series for awhile while I figure out what I'm going to do with them, I thought I would revamp a pair I did last summer with different drivers.
It will use the cabinets found here:
https://diy.midwestaudio.club/discussion/1692/second-summer-project/p1
But that is likely where the similarities end. I will going with the poly Dynavox 6.5 and currently Beast Mode in a Visaton guide. I have a pair of the XT25 and XT25 Beast (courtesy of Mr. Nick Claus) that I can use if the Beast Mode does not play well.
It models OK in a vented, better than the honeycomb did (which is why it was sealed). It should have a considerable presence in the bass region with the 38Hz extension and the 2db wide band ripple. May make baffle step comp tricky, or I may just build a speaker with some satisfying "thump". If I could stretch it to below 60Hz sealed, I would have kept the cabinets sealed but even anticipating using a small gauge air core crossing around 1.5K I can only get it to 65Hz and that is borderline for sealed bass that is also satisfying.
Anyways, ports already drilled and mounted and Beast Mode mounted to the guides using some nifty 3D printed adapters (thanks craig!). So already time for measurements. Maybe tomorrow. Mama and I are meeting some people this afternoon with shared interests, and then spending the night in the downtown Hilton. Before that, we are going to do our normal Saturday routine consisting of our weekly shopping around town, and we are considering getting a damn cat so may stop by the Humane Society to pet some shedders.
If they turn out to be too bass heavy (yeah, right) I will take care of that in the crossover. Worst case they will be a little short on energy between the bass ripple and the baffle step loss frequency. Best case is they will not need to be played loud to sound balanced.
Comments
Also, the yellow cones are at first blush a very pretty design I think the classic poly cone model has a more enduring appearance.
Speaking of, I will have a pair of the yellow cones for sale for anyone looking to duplicate one of the numerous designs that sprang forth at Indy.
Where I'm currently at. The image with a single line is the average of all horizontals. The waveguide is not optimal. The woofer is excellent.
I also switched to the big XT25. Guys, that is a serious tweeter.
Looks great JR! Are you using the older version of these woofers or what's currently on the Newark site?
This makes want to go back and look at the design I brought to Ankeny a few years ago with the truncated variants and the single magnet XT25s. It sounded too lean - Dave Ellis commented it likely just needed more baffle step.
Yep, the current version.
I'm not sure there is any difference between the old and new, I compared the old and new 5-1/4's and they were identical
...and they are all overhung, not underhung.
InDIYana Event Website
Spent quite a few hours last night listening, Mrs JR gives them full approval.
Crossover:
First Jantzen cap I have used - it was the only brand that had the 1.8uF I needed.
The big caps are a pair of 47uF in parallel for the LCR comp. I bought ten of them for something like $28 shipped from China.
Resistors are NOS Dale 10W and the Endura brand Leon used to sell. Terrible leads on the Endura, just horrible. The Dale use some manly leads and require effort to twist. The Endura will crumble and break seemingly at random. Nice looking and a nice high wattage rating, and all of them I have measured have come in at 1% or better.
Scott Hinson did a version with the LW6004 and a different version of the XT tweet if your interested.
https://www.facebook.com/DIYRM/posts/842940265880649
Dynavox plus ring radiator collection growing...
Distortion 90db@1M:
Both speakers together:
Impedance:
Anyways, named them "simplíoch" - old Irish for "simplicity"
Pronounced kind of like "shim lee uch". The "uch" is back of throat, like clearing your throat. Not like the German "Ach" or "Ich".
Looking at his project, I think it would be a little bright up top. My design uses a much better tweeter, is very, very close to time aligned mechanically, and subsequently is able to use what amounts to a slightly modified 2nd order LR network. I also used an LCR to tame the impedance peak on the tweeter, which I found necessary on the little one he used. Common omission on a lot of designs targeting the budget range but it helps remove the spittiness he was referring to in his earlier design attempts using the original XT25. The waveguide and the facets pretty much eliminate off-axis anomalies, as well. I wasn't targeting "budget", however and just spent some extra time and money on the waveguide, tweeter, cabinet and crossover than he did.
Interestingly, when I was struggling to hit 4th LR I ended up with the same values on the woofer as he did. It didn't play well with the wave guide, though.
I think it would be fun to do a head-to-head with the two designs. They are remarkably different approaches to using the same woofer and similar style tweeter.
I appreciate seeing various approaches and trying to learn from them. I'd be more inclined to go with your waveguide approach if I were to pick without hearing them. I have a xt19 version with waveguide and the LW5004. I heard issues with the tweeter, which I need to try and tame with the LCR as you did.
Curious, did you measure the T/S parameters of the LW6004 poly in this case?
I certainly did, and if I get to my real PC today I'll share them.
Hey JR,
I'm curious about your thoughts regarding the various tweeters you've tried with the waveguide. I have a pair of the Seos 8 guides that have an intended project. My initial thought has been to use one of the Seas soft domes (27TFFC like you used initially with the yellow cone Dynavox, or 27TDFC) as those are among the few tweeters that actually fit without significant modification. Seeing that you moved to beast mode/beast nipple for this project, I am wondering if you prefer them in your application and, if so, how you went about mounting them.
Sehlin Sound Solutions
I can't speak for anyone else's experience, but I find that hard domes and ring radiators generally work better in wave guides than soft domes. Soft domes have different phase response that usually makes the frequency response in the wave guide more wonky, for lack of a better term.
Scott, the Seas is a great tweeter but as Nick mentions the ring radiator just worked better.
I should add that the Beast Mode XT25 is very impressive.
Don't let the high Q fool you, these work just fine in vented enclosures.
Thanks for the insights JR and Nick. I will start a separate thread to discuss some of the various options/considerations for my project using the SEOS 8 and the woofer I plan to try to pair it with.
Sehlin Sound Solutions
These turned out really good. Spent many hours on them, and Saturday night we had a get together and spent the entire night listening to music (and drank a lot of beer). My little bro and some childhood friends were in town for a funeral, and we just had to have a night. Little bro jammed for awhile with my acoustic, wife sang. Josh is hell on wheels with a guitar. Between, we listened. These are really good at throwing a large soundstage and the bass is excellent, especially with the 40hz high pass protecting them.
Glad you like the Peerless in that waveguide. I plan on measuring my Beastmodes in that waveguide next week.