$vboptions[bbtitle]   $vboptions[bbtitle]  
  Terms and Conditions     Project Showcase
  Resource Index   Speaker Terms Glossary
  Security/Privacy   Speaker Replacement Help
Page 1 of 2 12 LastLast
Results 1 to 20 of 24
  1. #1
    Join Date
    May 2008
    Location
    Wausau, WI
    Posts
    332

    Default My First Sub Sim: Tang Band W8-740P

    The amp will be the Dayton MCA2550D 2.1 plate amp that is currently on sale.

    Its a 1.0cuF box with a a 2" x 11" port (a bigger box is ok if need be). It will be paired with the original Madisound Recession Busters from awhile back for use as monitors in desktop PC system for a friend of mine, with mixture of mostly music but some, movies and PC gamming.

    So how dose it look? Anything I need to address or I should consider tweaking? Go easy on me .





  2. #2
    Join Date
    Apr 2007
    Location
    Chicago-ish
    Posts
    1,034

    Default Re: My First Sub Sim: Tang Band W8-740P

    Looks good to me, but that driver could handle quite a bit more power, you'll probably be clipping that amp quite often even at moderate listening levels. Other than that the box looks good.
    ----------------------------------
    Gear:
    Samsung PN50A650
    Yamaha RX-V2500
    Hafler DH-200
    AC130MKII/BG NEO3PDR Two-Ways
    RS390HF-4 w/ HPSA500

  3. #3
    Join Date
    May 2008
    Location
    Wausau, WI
    Posts
    332

    Default Re: My First Sub Sim: Tang Band W8-740P

    Cool thanks.

    Yeah, its certainly capable of a lot more but I think that thats the amp he wants to go with since he's budget limited. Both the sub and the amp are currently on sale.

  4. #4
    Join Date
    Apr 2007
    Location
    Chicago-ish
    Posts
    1,034

    Default Re: My First Sub Sim: Tang Band W8-740P

    Quote Originally Posted by Operandi View Post
    Cool thanks.

    Yeah, its certainly capable of a lot more but I think that thats the amp he wants to go with since he's budget limited. Both the sub and the amp are currently on sale.
    I need to recant my statement, the port area is a bit too small, you want to keep the air velocity below 10% the speed of sound, ~350 m/s

    Edit: a 4 inch port will make it safe to about 150 watts if you ever upgrade to a bigger amp.
    ----------------------------------
    Gear:
    Samsung PN50A650
    Yamaha RX-V2500
    Hafler DH-200
    AC130MKII/BG NEO3PDR Two-Ways
    RS390HF-4 w/ HPSA500

  5. #5
    Join Date
    May 2008
    Location
    Wausau, WI
    Posts
    332

    Default Re: My First Sub Sim: Tang Band W8-740P

    Quote Originally Posted by JustinG View Post
    I need to recant my statement, the port area is a bit too small, you want to keep the air velocity below 10% the speed of sound, ~350 m/s

    Edit: a 4 inch port will make it safe to about 150 watts if you ever upgrade to a bigger amp.
    Ok, thats one thing I wasn't sure about which is why I included that graph.

    I'll mess around with it but the port lengths were getting pretty long with anything bigger than 2" to maintain the tunning freq. I was aiming for.

  6. #6
    Join Date
    Oct 2008
    Location
    near Rochester, NY
    Posts
    1,681

    Default Re: My First Sub Sim: Tang Band W8-740P

    In my limited experience, your curves predict a boomy sub.

    I'm also building a 2.1 systems based on this amp and RB-1s, and I looked at this woofer but discarded it as a poor fit. My Unibox sims are at home, but as I recall:
    - The Triska sub uses a Dayton SD215-88, which takes half the TB's power, but has 2.4dB greater rated sensitivity; sims show it playing 3dB louder at 50W.
    - in the wrong box, it's hard to get a smooth roll-off from the TB, ported or with PRs.
    This TB is a great match to one of the PE 240W sub amps, and begs for a larger (correction make that smaller) box.

    The second point, and my initial statement, deserve a little explanation. I find that flat low-frequency response on paper sounds boomy in room. Above a certain frequency which depends on room size, bass energy is stored in the room. Standing waves are set up and energy no longer dissipates as it does at higher frequencies. It's as if the room were amplifying the signal, thus the term "room gain."

    I find bass sounds best to me when I design to a gentle roll-off starting in the 50-80Hz range. I push box tuning below Fs to get the most extension, knowing that F10 can be half F3 and room gain will make up most of the difference. I want bass that moves me without booming.

    It leaves us both with the same question; where's the 2.1 plate amp with 50Wpc and 200W for the sub?

    Have fun,
    Frank
    Last edited by fbov; 02-16-2010 at 04:13 PM. Reason: Actually did the modeling...

  7. #7
    Join Date
    Nov 2009
    Location
    WI. Near the Infamous Dells. Pllhhh!
    Posts
    275

    Default Re: My First Sub Sim: Tang Band W8-740P

    Fbov -

    Intrigued by your statements regards a smaller box. I'm following this thread with interest as I have 4 of these drivers and trying to decide what to do with them.

    Until this thread I hadn't seen anyone using them. I read all the reviews and it's interesting to see that many claim good results with a multitude of box sizes.

    I'm considering a small horn but have no idea where to begin with that concept.
    'Soupy'

  8. #8
    Join Date
    Apr 2007
    Location
    Chicago-ish
    Posts
    1,034

    Default Re: My First Sub Sim: Tang Band W8-740P

    Quote Originally Posted by J.Lee View Post
    Fbov -

    Intrigued by your statements regards a smaller box. I'm following this thread with interest as I have 4 of these drivers and trying to decide what to do with them.

    Until this thread I hadn't seen anyone using them. I read all the reviews and it's interesting to see that many claim good results with a multitude of box sizes.

    I'm considering a small horn but have no idea where to begin with that concept.
    Here is a very quick model of a tapped horn in hornresp, it looks like it has potential, I can play around and get a smoother response out of it most likely. Not too bad for 2.5 cubic feet.



    ----------------------------------
    Gear:
    Samsung PN50A650
    Yamaha RX-V2500
    Hafler DH-200
    AC130MKII/BG NEO3PDR Two-Ways
    RS390HF-4 w/ HPSA500

  9. #9
    Join Date
    Oct 2008
    Location
    near Rochester, NY
    Posts
    1,681

    Default Re: My First Sub Sim: Tang Band W8-740P

    May I suggest Unibox for low frequency response modeling of enclosures. You can't beat doing the analysis yourself. You can find it (and lots of other good stuff) here:
    http://www.pvconsultants.com/audio/frdgroup.htm

    One tip. You'll have to add the TB to the database. I find it easier to copy an existing record for a similar driver, because the spreadsheet doesn't like blanks and it's not clear what all the fields are (like default box size). The T/S specs that you do enter are the important ones, as are the specs for a PR if you model it.

    What I'm finding is that this makes a nice sealed sub, but that it likes small, ported boxes with very low tune. That means long ports, 2-3x box size. It also opens the option of passive radiators. With the SD215s from the Triska, a single PR in a 1/2 cu ft box looks very nice, and even nicer with a little mass tuning. Unfortunately, this PR can't keep up with the TBs excursion....

    Four of these as mini-subs is intriguing, or as the bottom end of a 3-way. Just for grins, how about a 4-driver series/parallel arrangement in a 1 cu ft box with a port in the 1m range? Modeling lets you look anything, however improbable.

    Have fun,
    Frank

  10. #10
    Join Date
    May 2008
    Location
    Wausau, WI
    Posts
    332

    Default Re: My First Sub Sim: Tang Band W8-740P

    Alright so I played around a bit more and came up with something that is maybe a bit better, the response is similar but port velocity is under 250 ms now. Its a 0.86cuF box with a 2.5x 22" port so the port will need some elbow joints but I think it should fit. Thoughts on this one?


  11. #11
    Join Date
    Apr 2007
    Location
    Chicago-ish
    Posts
    1,034

    Default Re: My First Sub Sim: Tang Band W8-740P

    Quote Originally Posted by Operandi View Post
    Alright so I played around a bit more and came up with something that is maybe a bit better, the response is similar but port velocity is under 250 ms now. Its a 0.86cuF box with a 2.5x 22" port so the port will need some elbow joints but I think it should fit. Thoughts on this one?

    The only issue I see, that has been talked about in the other thread is that the sensitivity is a bit low on that woofer, not sure how loud your buddy plans on playing his music/movies but I'd like to see a bit more headroom than that if it were mine.
    ----------------------------------
    Gear:
    Samsung PN50A650
    Yamaha RX-V2500
    Hafler DH-200
    AC130MKII/BG NEO3PDR Two-Ways
    RS390HF-4 w/ HPSA500

  12. #12
    Join Date
    Sep 2005
    Location
    Appleton
    Posts
    7,085

    Default Re: My First Sub Sim: Tang Band W8-740P

    Quote Originally Posted by Operandi View Post
    Alright so I played around a bit more and came up with something that is maybe a bit better, the response is similar but port velocity is under 250 ms now. Its a 0.86cuF box with a 2.5x 22" port so the port will need some elbow joints but I think it should fit. Thoughts on this one?

    Take a look at putting it in 0.55 cf, with a 2.4" x 13" vent. You can get 2-1/2" PVC "electrical conduit" (they just don't make 2.5" plumbing drain pipe) at Lowe's or maybe Home Depot. Don't make the sub a cube, make it 16" on the long dim. and work the other 2 out to get .55 cf. I've built several like this.

  13. #13
    Join Date
    Oct 2008
    Location
    near Rochester, NY
    Posts
    1,681

    Default Re: My First Sub Sim: Tang Band W8-740P

    First off, my apologies Operandi for suggesting you do what you've already been doing.

    Second, can I assume that your box simulator includes a LP filter for the sub? That would explain your lack of sensitivity as the max driver output occurs at several hundred Hertz in Unibox. I'm seeing a minima at ~55Hz with your parameters that's missing in yours.

    Chris, when I run the numbers you suggest, I get a 45Hz tuning and a 4+dB peak at 55 Hz. I need a 20-30" port before I get a shape I like. Is it just a difference in taste, or are we modeling different things?

    HAve fun,
    Frank

  14. #14
    Join Date
    Nov 2009
    Location
    WI. Near the Infamous Dells. Pllhhh!
    Posts
    275

    Default Re: My First Sub Sim: Tang Band W8-740P

    Justin - thank you for that...food for thought.
    'Soupy'

  15. #15
    Join Date
    Jun 2008
    Location
    Austin,Texas
    Posts
    133

    Default Re: My First Sub Sim: Tang Band W8-740P

    if your not set on ported you might consider this guy's suggestion. though as you might notice in that thread he does get a bit of flack for using a driver shaping circuit.

  16. #16
    Join Date
    Apr 2007
    Location
    Chicago-ish
    Posts
    1,034

    Default Re: My First Sub Sim: Tang Band W8-740P

    Quote Originally Posted by J.Lee View Post
    Justin - thank you for that...food for thought.
    Yeah that was a quick (~2 minute) try at putting that woofer in a horn let me know how much sensitivity/extension/flatness you would want and I can see if I can put something together. Also, what size box you can get away with
    ----------------------------------
    Gear:
    Samsung PN50A650
    Yamaha RX-V2500
    Hafler DH-200
    AC130MKII/BG NEO3PDR Two-Ways
    RS390HF-4 w/ HPSA500

  17. #17
    Join Date
    Sep 2005
    Location
    Appleton
    Posts
    7,085

    Default Re: My First Sub Sim: Tang Band W8-740P

    Quote Originally Posted by fbov View Post
    First off, my apologies Operandi for suggesting you do what you've already been doing.

    Second, can I assume that your box simulator includes a LP filter for the sub? That would explain your lack of sensitivity as the max driver output occurs at several hundred Hertz in Unibox. I'm seeing a minima at ~55Hz with your parameters that's missing in yours.

    Chris, when I run the numbers you suggest, I get a 45Hz tuning and a 4+dB peak at 55 Hz. I need a 20-30" port before I get a shape I like. Is it just a difference in taste, or are we modeling different things?

    HAve fun,
    Frank

    When I reaad your post, I noticed that the -740 was now a "P" version. Holy sheesh! I was modelling the 740C. Anyway, I checked the parms and they're nearly identical.

    My old data included Le, and while WinISD does show a peak, it's more like +1 in the mid 40's, showing a tuning of 39 Hz for a 2.4"id x 13" long vent in a 0.55 cf box. Does Unibox really show that as a 45 Hz tuning? That seems like quite a difference in tuning to me, and should NOT even be affected by driver parms. My BR-1 clones are in this exact box (with tuning) and my WT3 shows the Fb to be really close to 40 Hz.

    Any way, with the "P" parms modelled (and no Le value), the curve does look a lot nicer once you get the port length up to 20", but peaking in the 40's (or even 50's) looks a lot less ugly when you DO model in a 2nd order lowpass, even as high as 100 Hz. This seemed like a budget project to me, with the amp and driver on sale, so I'm trying to keep the box cost down (no PR).

    Chris

  18. #18
    Join Date
    Oct 2008
    Location
    near Rochester, NY
    Posts
    1,681

    Default Re: My First Sub Sim: Tang Band W8-740P

    Quote Originally Posted by Chris Roemer View Post
    ... the curve does look a lot nicer once you get the port length up to 20", but peaking in the 40's (or even 50's) looks a lot less ugly when you DO model in a 2nd order lowpass, even as high as 100 Hz. This seemed like a budget project to me, with the amp and driver on sale, so I'm trying to keep the box cost down (no PR).

    Chris
    I'm not including a filter, so that's reasonable. And I agree about the budget, I just like the DVC sub a lot better with this 2.1 amp. In fact, the parts for my 2.1 Triska (including MDF) are sitting on my dining room table. Hoping to make sound by this weekend, so I can stop talking about simulations....

    Frank

  19. #19
    Join Date
    Sep 2005
    Location
    Appleton
    Posts
    7,085

    Default Re: My First Sub Sim: Tang Band W8-740P

    Quote Originally Posted by fbov View Post
    I'm not including a filter, so that's reasonable. And I agree about the budget, I just like the DVC sub a lot better with this 2.1 amp. In fact, the parts for my 2.1 Triska (including MDF) are sitting on my dining room table. Hoping to make sound by this weekend, so I can stop talking about simulations....

    Frank
    Here's my Triska, but this one's PR free!
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	LittleWhiteSub6.jpg 
Views:	106 
Size:	91.2 KB 
ID:	7049  

  20. #20
    Join Date
    Oct 2008
    Location
    near Rochester, NY
    Posts
    1,681

    Default Re: My First Sub Sim: Tang Band W8-740P

    That's not a 13" cube... you sure it's a Triska? You better have one 13" dimension or I'm blowing you in to Shawn for misappropriation of naming rights. (Mine are 13x14x14, but for good reason.)

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  




Your #1 Source for Audio, Video & Speaker Building Components


Clearance Center
Deal of the Day
New Products




View Our latest
Sales Flyer

Prices Effective
Through 4/30/14


Order our FREE 336 Page Full Color Catalog



Speaker Component Categories

Home Audio Speakers

Professional Audio & Guitar Speakers

Car Audio Speakers

Speaker Buyouts

Measurement & Design Tools

Subwoofer Plate Amplifiers

Full-Range Plate Amplifiers

Crossover Components

Cabinet Hardware & Speaker
Grill Cloth

Speaker Cabinets

Subwoofer System Kits

Speaker Kits

Speaker Repair Parts

Speaker Wire