Finally gonna start. TD15M + SEOS18 + DNA-360?

Discussion in 'DIY Speakers and Subwoofers' started by JoshK, Dec 11, 2013.

  1. I've had the parts for quite some time now but have been otherwise pre-occupied and don't have a shop to build boxes anymore. I am going to ask one of the local cabinet markers here to build the box for me and I'll do the rest. I thought I'd start a thread for this project in case anyone wanted to follow along, or borrow/steal ideas.

    I have a pair of Tannoy Arundel 15" coax speakers that are roughly 7cuft internal volume, which happens to be pretty ideal for the TD-15M when tuning to 40hz (more on this later). I have owned the Arundels for some time and their size and dimensions is pretty tolerable and nice looking to me, so I am staying in this ballpark. This puts the waveguide at the right ear height from my estimation as well.

    The design is intended to be a full range floor standers that can be run without subs for music, so that I can bring them upstairs to my all tube music system if I ever get the kick. The max power excursion gets a bit violated down real low in my design if you put a ton of power into them, which I will never do for music and would likely HP them ~60hz in my HT system if I really want to crank it (I live in an apartment, so not likely).

    The dimensions are roughly 39" tall x 20" wide x 19" deep. (the arundels are 39.4 x 19.6 x 19.25, so close to the same, but I wanted to make the dimensions rounded to the nearest inch to make building easier and the SEOS18 is 18.4" wide).

    The Unibox parameters are as follows:

    [table] [tr] [td][/td][td]Design by Vb, Fb and Q[/td] [td] [/td] [/tr] [tr] [td]Physical Vb[/td] [td][/td] [td]l[/td] [/tr] [tr] [td]Absorption, Qa[/td] [td][/td] [td] [/td] [/tr] [tr] [td]Leakage, Ql[/td] [td][/td] [td] [/td] [/tr] [tr] [td]Port, Qp[/td] [td][/td] [td] [/td] [/tr] [tr] [td]Alpha, a[/td][/tr][/table] 1.581[/t][/t] [table][tr] [td]Vb[/td] [td][/td] [td]l[/td] [/tr] [tr] [td]Fb[/td] [td][/td] [td]Hz[/td] [/tr] [tr] [td]F3[/td] [td]
    [/td] [td]Hz[/td] [/tr] [tr] [td]Response peak[/td] [td]
    [/td] [td]dB[/td] [/tr] [tr] [td]Peak at[/td] [td]58.08[/td] [td]Hz[/td] [/tr] [tr] [td]Port min dia.[/td] [td]
    [/td] [td]cm[/td] [/tr] [tr] [td]Port length[/td] [td][/td] [td]cm[/td] [/tr] [tr] [td]Port 1. resonance[/td][/tr][/table] [/t] [table][tr][td]
    [​IMG] [table] [tr] [td]Hz[/t][/t][/t]​

    This looks pretty good to me, especially for music, which is hands down my first priority. I watch movies, but typically never blockbuster/action types, more foreign/comedy/drama types. Except for electronic music and pipe organ music, the vast majority of music is >40hz, so these go low enough on their own to meet my desires.

    The above box will use 3x 3" flared ports roughly 3-3.5" in length. Perusing some other folks' designs who were using TD15M full range in music based systems turned up similar tunings (Steve Scholl for example) which gives me some piece of mind that my choices were sound.

    I originally had planned to use my B&C DE250 CDs, but I can only find one after my move. I've searched high and low and the other seems to have gone AWOL. As soon as I buy some others, I am sure it will turn up. The problem now is that B&C apparently changed the DE250 (according to Dr. Geddes and others), and my DE250s were the older (supposedly better) ones. The DNA-360 from that big huge thread on AVS looked to be drop in replacements, or close enough that I can order a pair of them and use my sole DE250 in the mean time to rough up a crossover, which I can tweak later if needed.

    Disclosure: I've been doing DIY audio for over ten years now (mostly built tube electronics). I've read tons and tons on measuring and designing speakers. My background is in mathematics/statistics and tend to be fairly technically inclined. However, to date I have never actually measured and designed a crossover on my own, so this will be maiden voyage down this avenue. I have looked at Bwaslo's crossover for the TD15M+SEOS15+DNA-360 and understand what is going on, plus I had a pair of Geddey's abbeys and had the xo schematic which I understood as well. The devil is always in the details, so I'll lean on some forum members here as I try to execute it myself.

    The above mentioned Bwaslo design is a pretty good design for comparison, however, the SEOS18 is deeper, so the acoutic center of the waveguide will be further back. I think I will examine rear mounting the TD-15M to help with closing in the acoustic offsets. I also plan to try out the Geddes' style foam plug.

    Before I hire a cabinet worker to start making dust, I'd appreciate some feedback on my box design thus far. I'll post some of the gifs from unibox in the following thread.

  2. As promised the response from Unibox.

    I also am attaching a picture of my Tannoy's just for visual comparison.

    Attached Files:

  3. Somewhere in that big @$$ thread on SEOS waveguides, I had a discussion with some members over using the SEOS18 instead of the SEOS15 when pairing with a 15" woofer. With the above disclosure in mind, when I examined the measurement data, the SEOS18 looked ever so slightly more ideal to mate with a 15" than the SEOS15 despite the aesthetic considerations, which is why I went with the 18. It could be inconsequential, but never-the-less I like using the larger waveguide for distortion reasons, power response matching, etc.
  4. I cannot offer any assistance with what you are looking for, but I do hope you continue to share your plans, pictures, and results.
  5. As discussed over on AVS in another member's thread, I played around a bit more and I am liking 6cuft (172L) tuned to 42hz better. That will take about 200w input down to 35hz before running out of excursion. That is good enough for music listening, saves a tiny bit of volume and can still be crossed higher if wanted reference HT levels.

    I drew up box plans on a napkin (ok, sheet of paper) but I am thinking of drafting the plans in sketchup so I can have a cabinet maker knock them up for me. Gotten remember how to use sketchup, especially doing the braces.
  6. The 172L design specs

    Attached Files:

  7. Took the plunge and ordered Radian 475 Be drivers for these. :eek:
  8. I am curious how they measure and work for you (both the radian and the waveguide). Radian is based here in SoCal. I almost bought some just for that reason. Well, that and they are high quality units. Will be watching and learning.
  9. Looking forward to hearing more about this build:)
  10. I'm also starting construction of SEOS18/TD15M speakers. I've been vacillating between building 3cu. ft sealed bass boxes and ~5cu.ft. vented boxes. Of course, the vented boxes would extend lower but I already have 3 subs. However going vented would allow the TD15M's to contribute to the distributed bass scenario. Sealed would be easier to build and may have slightly better SQ.

    I plan to mount the WG on top either in a separate small box or with some sort of bracket. You mentioned the acoustic offset problem. Back mounting the woofer is a good idea. Since my wave guide will have it own box or bracket perhaps I could extend it a bit beyond woofer baffle to compensate a little more for the offset.

    It's great that you have bought the Radian 475 Be CD's. I'd buy them if I had the spare $$. I have the BA750's. I suspect you'll get more high end extension, maybe less distortion and some more sweetness. One good thing about the BA's is that they extend down into the 600hz range. I'll soon know if I hear any titanium diaphragm aural irritation or not.
    I'm building the enclosures myself. I also have to deal with implementing an active crossover.
  11. I'm vacillating too. Think I may just go sealed, flip them upside down ontop of my TD15X+dual PR bass bins I have now for a three way. My version of the mega SEOS. 8) [/size] I was going to use those bass bins upstairs in my audio room, but I think I am building tapped horns instead for my audio room (THAM15). Not 100% sure yet, analysis paralysis.

    [font=verdana, sans-serif][/size]According to my modeling, 3cuft works but 3.75cuft (110L) sealed was more ideal.

  12. Hmm... 3.75. I should go back an check my numbers. I'm using WinISD beta for calculations and I came up with 3.069 cu ft as optimum. The Qtc is 0.71 which is also optimum. I did go back and checked the parameters and they're correct. Actually I read it might be best to build the box slightly larger than the theoretically ideal size so its possible to retroactively make adjustments for the type and amount of stuffing used. You can also adjust box size by inserting a block of wood or whatever to eat up some space and raise the Qtc.
  13. Actually I see where we are differing. I was using 0.56 to obtain 109.5L with heavy fill. 52L for 0.707 with heavy fill and 76L with "walls covered". I am modeling in Unibox as I know it well. Not sure which is more accurate. But ~3cuft looks pretty good.
  14. Did you ever get these going? I have almost the same setup except using bms 4550's. We're you going active crossover? I won't be able to measure for a while and was looking for active xover starting points. I should have these up and running by the end of this week, so I will start playing with them.
  15. So far I've been slow on looking into having a cabinet builder build the cabinets for me. That is the slow part. I intend to make a passive crossover, FWIW.
  16. Any updates?

  17. No, problem is I keep vacillating, but I have a cabinet maker now that will give me a quote if I draw plans. I have half a mind to use the SEOS 18 with Dual JBL 2226H's each in a 2.5 way setup and sell them upon completion. I have too many speakers and I have 6 JBL 2226Hs. I drew a rough drawing of what that would look like at it puts the SEOS's center line at 37", which is just a hair above optimal (34-36" depending on person). That seems to work and would provide 8cuft tuned to 30hz and F3 in mid 40's.
  18. That would be a cool speaker :)

    I think I saw some of your ads on canuckaudio mart to get rid of your giant mahogany horns :mad:
  19. I don't have the room to set them up correctly, but would love to keep them in a whole system. We shall see, in the mean time I have an ad out there to see if anyone bites.

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