Jump to content


Sign in to follow this  
1995Tercel

EXPERTS ONLY PLEASE Building the perfect transmission line box, many questions

Recommended Posts

Vehicle : 2000 Honda Insight

Location in the vehicle: Terminus output behind driver seat, subwoofer facing rear of the car, under the package shelf

Space available (Length x Width x Height): Depends on what design I end up with, I'm going to try and fit the box we come up with.

Subwoofer make and model: Sundown Audio SA-8 V3

Subwoofer Size: 8inch

Number of Subwoofers: one

Amplifier make and model: Sundown Audio SAE-600D

Type of Port (Kerfed, Slot, Aero, etc.): circular

What type of music do you like?: all

Is your goal SPL or Everyday Music?: Goal is maximum extension (minimal Db taper past 20Hz), zero resonance, perfect bass. How loud the system gets is not a concern for me. Complete focus on quality.

Tuning Freq (Hz): I'm not sure, but the FS Hz for the subwoofer is 38.29

Volume : Also not sure

Questions: So, I'm attempting to make a straight tline box, but I just don't know where to begin. It is difficult to find practical information on this style box, as almost every single box i see, is done incorrectly. I also cant rely on calculations for those boxes, for the same reason. Many boxes I see have a parallel wall opposite the subwoofer (on top of zero sound deadening, with all parallel walls) which is all very poor design.

 

Just so people helping me are on the same page, Tline boxes exist to reduce or eliminate resonant frequencies, should be tapered wall, terminus output port 1/3 to 1/4 the area of the subwoofer radiating surface area, the first half of the transmission line lined with TL (not sure what this acronym stands for) second half filled with BAF Wadding. (If I'm wrong on this, please correct) I will also attempt to fit the box without compromising the design, so no internal turns or baffles, just straight.

 

1a. I think I need a bass chamber, that is 1/5th the wavelength distance, but I'm not sure what bass chamber means, what wavelength I need to use, or how to calculate volume of the box. Do I use the 38.29Hz of the subwoofer FS value? (Using that value I get a 1/5th wavelength distance of 69.40in at the calculated yearly average temperature of 50 degrees f where I live.)

 

1b. What is a bass chamber in a Tline box? Is "bass chamber"just referring to the overall structure of the box?

 

1c. I have read that I need to add a small distance to the overall length of the sub box to accommodate "end correction." How do I calculate this distance? This is another critical aspect, as the proper amount greatly increases low end extension.

 

1d. How do I cancel out the 3rd fundamental harmonic? the 5th one is done with the proper calculation of 1a.

 

2. What is the radiating surface area of my sub? I contacted Sundown audio, they just told me its 50.24 square inches, which is simply using a full 8 inch radius. I am very skeptical of this, as I've read this can be significantly different actual area among different subs. I need the exact area, because the port on the opposite end of the box needs to be between 1/3 and1/4th the area.

 

3a. How do I know what volume to use for the entire box?

 

3b. How do I calculate this volume?

 

3c. Are there separate volumes I need to calculate? Or is does this box simply taper from the subwoofer to the port?

 

Thank you for your assistance and expertise.

Share this post


Link to post
Share on other sites

https://www.diysubwoofers.org/tls/

Do download and figure out how to use hornresp software.  EVERYBODY I have ever seen trying to build any type of horn, bin, or quarter wave box uses it. 

You can safely say you'll lose an inch from the diameter of the driver for surround, that should get you close enough.  Speaking of close enough if you're off on an end 3hz change in tuning of a box is inaudible in my experience and even 5hz is barely audible so don't drive yourself crazy there.

According to that source the unwanted high resonances that you think you want to tame with stuffing are only an issue in full range system so you should not need any batting unless you're trying to cheat a shorter line and from my experience with stuffing in general while you can change response slightly you pay for it with efficiency.

I do not believe you need a chamber for a true transmission line, that becomes more of a horn or just a ported box.  AFAIK true T-line is the woofer firing into the line which is consistent length throughout.  Having an odd size chamber puts you more into horn territory, though I suspect the hornresp software will have options where you can play with that.

Lastly I think if you want to play down to 20hz you will not be able to build this without a bend.   You are getting into a LONG wavelength, and that said I'm not sure how far below FS you can go with a t-line.   There have only been a handful of guys on this forum who have built these so if you want better, do a forum search and see who has done them, PM those guys and hope they're still active.  Good luck and please post a build log as you go.  I've heard one proper T line in person and it sounded very nice.   Almost worth the space and the wood.   Mind you, with today's EQ options and how cheap power is and how robust our woofers are there's no reason you can't get flat from 20-80hz in the same space a few different ways these days.   I'd consider T-line not something you "have to have" in order to get a particular sound but just an alternative as something to do if you like a good DIY woodworking challenge and interesting conversation piece.

Might even get better horn/tline discussion going at diyaudio forum or another home theater forum.  Home theater guys don't care about size of enclosure and are much more likely to have experimented with these sorts of designs... car audio guys these days lean heavily on cheap power and robust woofers to leverage the hell out of box size when wrestling Hoffman's Iron Law and the market has mostly focused on delivering options along that line of approach.

 

Good luck and please post a build log here.

  • Like 1

Share this post


Link to post
Share on other sites

Experts only so let’s see what @BOOMINGRANDPA can advise 

  • Like 1

My wife doesn’t know about my car audio addiction...shhhh

Share this post


Link to post
Share on other sites

Gramps advice will go something like this:

get a pioneer 3003 and put in prefab, make shure to power speakers with head yoonit 

  • Like 1

giphy.gif

Share this post


Link to post
Share on other sites
On 11/8/2018 at 5:00 PM, hispls said:

https://www.diysubwoofers.org/tls/

Do download and figure out how to use hornresp software.  EVERYBODY I have ever seen trying to build any type of horn, bin, or quarter wave box uses it. 

You can safely say you'll lose an inch from the diameter of the driver for surround, that should get you close enough.  Speaking of close enough if you're off on an end 3hz change in tuning of a box is inaudible in my experience and even 5hz is barely audible so don't drive yourself crazy there.

According to that source the unwanted high resonances that you think you want to tame with stuffing are only an issue in full range system so you should not need any batting unless you're trying to cheat a shorter line and from my experience with stuffing in general while you can change response slightly you pay for it with efficiency.

I do not believe you need a chamber for a true transmission line, that becomes more of a horn or just a ported box.  AFAIK true T-line is the woofer firing into the line which is consistent length throughout.  Having an odd size chamber puts you more into horn territory, though I suspect the hornresp software will have options where you can play with that.

Lastly I think if you want to play down to 20hz you will not be able to build this without a bend.   You are getting into a LONG wavelength, and that said I'm not sure how far below FS you can go with a t-line.   There have only been a handful of guys on this forum who have built these so if you want better, do a forum search and see who has done them, PM those guys and hope they're still active.  Good luck and please post a build log as you go.  I've heard one proper T line in person and it sounded very nice.   Almost worth the space and the wood.   Mind you, with today's EQ options and how cheap power is and how robust our woofers are there's no reason you can't get flat from 20-80hz in the same space a few different ways these days.   I'd consider T-line not something you "have to have" in order to get a particular sound but just an alternative as something to do if you like a good DIY woodworking challenge and interesting conversation piece.

Might even get better horn/tline discussion going at diyaudio forum or another home theater forum.  Home theater guys don't care about size of enclosure and are much more likely to have experimented with these sorts of designs... car audio guys these days lean heavily on cheap power and robust woofers to leverage the hell out of box size when wrestling Hoffman's Iron Law and the market has mostly focused on delivering options along that line of approach.

 

Good luck and please post a build log here.

Agreed 100%.  Excellent response here.

I've built some and had luck.  I did not tune below driver Fs so I cannot comment on the effect.  I agree with having an efficient transition from the driver airspace into the T-Line.  I built enclosure-coupled T-lines but put focus on a good transition.


2014 Accord Sport build log:

My YouTube Channel: https://www.youtube.com/channel/UCkYUo2EShW9lgtrfXiDvLNQ/videos

My 1966 MGB Restoration: http://www.mgexp.com/journal/keephopealive

Fix Photobucket Image Loading ------> https://addons.mozilla.org/en-US/firefox/addon/photobucket-fix/ <------

2016caraudiologos (2).jpg

 

Share this post


Link to post
Share on other sites
On 11/8/2018 at 6:14 PM, MattinMO said:

Experts only so let’s see what @BOOMINGRANDPA can advise 

Yep. He has been telling everyone on Facebook the FU 750s will take 1500rms and the 300s will take 750. 

Edited by Popwarhomie
  • Confused 1

2016 Focus ST3 - Rockford DSR1 / PPI 900.4 / Silverflute 6.5" mids / Massive CT2 tweeters /Sundown Xv2 15"/ Taramps DSP3k / Stinger Roadkill / KNU wiring / Northstar SMSAGM80 /

2010 Focus coupe 157@46hz

Pioneer 80prs /(8) FU Audio 750 12"s / (4) FSD 2600s / (1) FSD 125.4 / (1) FSD 85.4 / (4) Crescendo UN-10" mids / (4) Crescendo FT1 tweeters / Stinger Roadkill / 2/0 EB flex wire / (5) Powerware 90AH batteries / DC 270XP Alt /

https://www.youtube.com/popwarhomie

too many freq at once, burn the coil, we all know, over 40-50hz, its all coilburning material.

Share this post


Link to post
Share on other sites
8 minutes ago, Popwarhomie said:

Yep. He has been telling everyone on Facebook the FU 750s will take 1500rms and the 300s will take 750. 

Has he stated his source for this informational nugget?

Or is it just his expertise?

Edited by shredder2

JVC KD-X350BTS, Sundown Sa-15 33.5hz 3.8ft3 ported, Synergy 3K@ 2 ohm, RF 500s, Polk DB comps, Cache Preamp/EQ... or...

JVC KD-X350BTS, Kicker S10L72 1.75ft3 ported, Synergy 3K @ 1 ohm, RF 500s, Polk DB comps, Cache Preamp/EQ...

Share this post


Link to post
Share on other sites
14 minutes ago, shredder2 said:

Has he stated his source for this informational nugget?

Or is it just his expertise?

His experience with giving his FU 750 311 watts.    "bUt ThIs GuY sAiD hIs ToOk A 5k nO prObLeM."


2016 Focus ST3 - Rockford DSR1 / PPI 900.4 / Silverflute 6.5" mids / Massive CT2 tweeters /Sundown Xv2 15"/ Taramps DSP3k / Stinger Roadkill / KNU wiring / Northstar SMSAGM80 /

2010 Focus coupe 157@46hz

Pioneer 80prs /(8) FU Audio 750 12"s / (4) FSD 2600s / (1) FSD 125.4 / (1) FSD 85.4 / (4) Crescendo UN-10" mids / (4) Crescendo FT1 tweeters / Stinger Roadkill / 2/0 EB flex wire / (5) Powerware 90AH batteries / DC 270XP Alt /

https://www.youtube.com/popwarhomie

too many freq at once, burn the coil, we all know, over 40-50hz, its all coilburning material.

Share this post


Link to post
Share on other sites
3 hours ago, Popwarhomie said:

His experience with giving his FU 750 311 watts.    "bUt ThIs GuY sAiD hIs ToOk A 5k nO prObLeM."

mucho powa

  • Haha 1

2)American Bass VFL Mini Hybrid 4480.1D@1ohm Ea 4)American Bass XFL DVC 4ohm 12s@2.06cu Ft Ea.@32htz CDT 6,5 HD6 Briax.,CDT CL60,CDT 25 tweets,Kicker KS25 tweets Autotek Mean Machine 99@2ohms,Autotek BTX 7204@40hms AlterStarts Alt 255A/Dallas,Tx,2)Orileys Super Start AGM batts(1more coming)Cadence CCA 0ga on Big 6,AudioTechnix 0ga CCA Kicker Kq9 Eq,Eclipse CD3000(lookingfor upgrade)StingerPro Distro,3)XS Scorpian 8in Scroll Fans 1998 3dr Xcab Chevy(under construction,but operational)

Share this post


Link to post
Share on other sites
18 hours ago, Popwarhomie said:

Yep. He has been telling everyone on Facebook the FU 750s will take 1500rms and the 300s will take 750. 

Of course if he said the SA12 will take 1500W, that's A-OK because everyone knows that Sundown uses magic unicorn tears to make their 2.5" coils handle double rated power.

I'd imagine most people could get away with running FU750 on a 1500W rated amp and be fine, same as SA or DD25XX.   My issue has always been if someone needs to ask how much power to use they have no business trying to exceed rated.

  • Thanks 1

Share this post


Link to post
Share on other sites

wow basically a whole thread about me and i said nothing and people do run 1500 to 750's guy here laughed at my amp because he ran a ppi 1800 to his for yrs.. also popwar u were running like 1300rms to 750's right? so how am so how am i wrong? either way idk why i was brought into this at all


KENWOOD X301 HU, PRECISION POWER Phantom 1000, FU 750 12, 2.1cfad ported, soundqubed 6.5" coax/doors, hp & lp xover on hu, AGM starting batt...

Boomin_tahoe said:
2 ohms rule

Share this post


Link to post
Share on other sites
23 hours ago, Popwarhomie said:

Yep. He has been telling everyone on Facebook the FU 750s will take 1500rms and the 300s will take 750. 

now that i think about it u told me on fb to get  1 300 and run 1k to that but now u flaming me for saying 300's can take power?


KENWOOD X301 HU, PRECISION POWER Phantom 1000, FU 750 12, 2.1cfad ported, soundqubed 6.5" coax/doors, hp & lp xover on hu, AGM starting batt...

Boomin_tahoe said:
2 ohms rule

Share this post


Link to post
Share on other sites

Running a 1500 watt amp does not mean your subwoofer is seeing 1500 watts...

 

Everyone and their sister claims they are putting double rated power to their subwoofer yet have NEVER clamped actual power.  


2016 Focus ST3 - Rockford DSR1 / PPI 900.4 / Silverflute 6.5" mids / Massive CT2 tweeters /Sundown Xv2 15"/ Taramps DSP3k / Stinger Roadkill / KNU wiring / Northstar SMSAGM80 /

2010 Focus coupe 157@46hz

Pioneer 80prs /(8) FU Audio 750 12"s / (4) FSD 2600s / (1) FSD 125.4 / (1) FSD 85.4 / (4) Crescendo UN-10" mids / (4) Crescendo FT1 tweeters / Stinger Roadkill / 2/0 EB flex wire / (5) Powerware 90AH batteries / DC 270XP Alt /

https://www.youtube.com/popwarhomie

too many freq at once, burn the coil, we all know, over 40-50hz, its all coilburning material.

Share this post


Link to post
Share on other sites
7 hours ago, BOOMINGRANDPA said:

now that i think about it u told me on fb to get  1 300 and run 1k to that but now u flaming me for saying 300's can take power?

You have no clue what impedance rise is do you...


2016 Focus ST3 - Rockford DSR1 / PPI 900.4 / Silverflute 6.5" mids / Massive CT2 tweeters /Sundown Xv2 15"/ Taramps DSP3k / Stinger Roadkill / KNU wiring / Northstar SMSAGM80 /

2010 Focus coupe 157@46hz

Pioneer 80prs /(8) FU Audio 750 12"s / (4) FSD 2600s / (1) FSD 125.4 / (1) FSD 85.4 / (4) Crescendo UN-10" mids / (4) Crescendo FT1 tweeters / Stinger Roadkill / 2/0 EB flex wire / (5) Powerware 90AH batteries / DC 270XP Alt /

https://www.youtube.com/popwarhomie

too many freq at once, burn the coil, we all know, over 40-50hz, its all coilburning material.

Share this post


Link to post
Share on other sites
13 hours ago, Popwarhomie said:

You have no clue what impedance rise is do you...

right so why is it ok for u top tell me to run 1k to a sub but not ok for me to say 750? or 1500rms for a fu 750 when there are people running fsb 1600 to 1 or even a 3k amp on 1.. u may have seen guy just said he ran taramps 8k on 4 of them  a long time no problems.. don't tell me about rise when u are correcting me for tell people to "over power" subs because of rise


KENWOOD X301 HU, PRECISION POWER Phantom 1000, FU 750 12, 2.1cfad ported, soundqubed 6.5" coax/doors, hp & lp xover on hu, AGM starting batt...

Boomin_tahoe said:
2 ohms rule

Share this post


Link to post
Share on other sites
24 minutes ago, BOOMINGRANDPA said:

right so why is it ok for u top tell me to run 1k to a sub but not ok for me to say 750? or 1500rms for a fu 750 when there are people running fsb 1600 to 1 or even a 3k amp on 1.. u may have seen guy just said he ran taramps 8k on 4 of them  a long time no problems.. don't tell me about rise when u are correcting me for tell people to "over power" subs because of rise

You had just better hope Kuthe or Papermaker comes back to take the heat off you at this point.  You've said some dumb shit here and you are just currently the low man on the pecking order these days.

Share this post


Link to post
Share on other sites

I'm currently running a T-line tuned to 34Hz. Will play down to 28Hz and upwards of 90Hz. It's a very bandwidth enclosure. Sub is a DC Audio m3 8

1123.jpg

1137.jpg

017.jpg

003.jpg


97 4 dr. Tahoe

Interstate battery

Alpine 9835

Polk Audio MM6501 comps

Wolfram amps coming soon, 3000.1, 125.4

2 Sundown Audio X 15's Tuned @ 30Hz.

Knukonceptz/Royal Excelene wiring

Share this post


Link to post
Share on other sites
4 hours ago, hispls said:

You had just better hope Kuthe or Papermaker comes back to take the heat off you at this point.  You've said some dumb shit here and you are just currently the low man on the pecking order these days.

yeah i'm not here anoymore either there are much better places to be i just come back to answer pm's.. this site has to many Aholes that flame me for saying same thing they do.. and 1 guy designed a box that was to big for guys cheap subs for the power he had 1 blew and he blamed the subs.. i knew box was to big and pm'ed the guy and told him so.. i was right but the everyone here loves the guy that designs bad boxes and tells me idk what i'm talking about, whatever


KENWOOD X301 HU, PRECISION POWER Phantom 1000, FU 750 12, 2.1cfad ported, soundqubed 6.5" coax/doors, hp & lp xover on hu, AGM starting batt...

Boomin_tahoe said:
2 ohms rule

Share this post


Link to post
Share on other sites
7 hours ago, BOOMINGRANDPA said:

right so why is it ok for u top tell me to run 1k to a sub but not ok for me to say 750? or 1500rms for a fu 750 when there are people running fsb 1600 to 1 or even a 3k amp on 1.. u may have seen guy just said he ran taramps 8k on 4 of them  a long time no problems.. don't tell me about rise when u are correcting me for tell people to "over power" subs because of rise

I told you you would be better off getting the FU300 because you are probably getting 300 watts with your 1k amp after rise and on stock electrical.... Yet you continue to tell everyone you are putting 900rms to your subwoofer.

 

I ran a f*****g Taramps T20k on two subwoofers. Did I claim they are getting 10k each? Nope not even close.

 

Are you going to warranty subwoofers for these companies when the people you are telling they can handle double rated power blow theirs up?

Edited by Popwarhomie

2016 Focus ST3 - Rockford DSR1 / PPI 900.4 / Silverflute 6.5" mids / Massive CT2 tweeters /Sundown Xv2 15"/ Taramps DSP3k / Stinger Roadkill / KNU wiring / Northstar SMSAGM80 /

2010 Focus coupe 157@46hz

Pioneer 80prs /(8) FU Audio 750 12"s / (4) FSD 2600s / (1) FSD 125.4 / (1) FSD 85.4 / (4) Crescendo UN-10" mids / (4) Crescendo FT1 tweeters / Stinger Roadkill / 2/0 EB flex wire / (5) Powerware 90AH batteries / DC 270XP Alt /

https://www.youtube.com/popwarhomie

too many freq at once, burn the coil, we all know, over 40-50hz, its all coilburning material.

Share this post


Link to post
Share on other sites
1 hour ago, BOOMINGRANDPA said:

yeah i'm not here anoymore either there are much better places to be i just come back to answer pm's.. this site has to many Aholes that flame me for saying same thing they do.. and 1 guy designed a box that was to big for guys cheap subs for the power he had 1 blew and he blamed the subs.. i knew box was to big and pm'ed the guy and told him so.. i was right but the everyone here loves the guy that designs bad boxes and tells me idk what i'm talking about, whatever

 

Who would PM you asking for your help?

 

You run stock electrical.

You have never built a box

You couldn't re glue a subwoofer surround. 

You run coaxial door speakers off headunit power.

You keep giving advise to things you have ZERO experience with.

 

You are a stay at home mom who smokes 4 packs a day yet complains about not being able to afford anything and yet your english and grammar is still horrible.

 

 

 

 

  • Thanks 1
  • Haha 1

2016 Focus ST3 - Rockford DSR1 / PPI 900.4 / Silverflute 6.5" mids / Massive CT2 tweeters /Sundown Xv2 15"/ Taramps DSP3k / Stinger Roadkill / KNU wiring / Northstar SMSAGM80 /

2010 Focus coupe 157@46hz

Pioneer 80prs /(8) FU Audio 750 12"s / (4) FSD 2600s / (1) FSD 125.4 / (1) FSD 85.4 / (4) Crescendo UN-10" mids / (4) Crescendo FT1 tweeters / Stinger Roadkill / 2/0 EB flex wire / (5) Powerware 90AH batteries / DC 270XP Alt /

https://www.youtube.com/popwarhomie

too many freq at once, burn the coil, we all know, over 40-50hz, its all coilburning material.

Share this post


Link to post
Share on other sites

Create a free account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's free & easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×