AVS › AVS Forum › Audio › DIY Speakers and Subs › DIY HT Design...Ported or Sealed?
New Posts  All Forums:Forum Nav:

DIY HT Design...Ported or Sealed?

post #1 of 43
7/6/09 at 4:22am
Thread Starter 
Another quick recap. Budget is $750 per pair. Bass extension is 60hz +/-10hz. Design must be stand mountable and Baffle width no greater than 12". With practical cabinet dimensions, that gives us a maximum gross volume of about 2.25cuft give or take. Now since this design will be mated to a subwoofer(s), the question that begs asking is should it be Ported or Sealed....or might i even add Passive Radiator. I won't go into any of the drawbacks or benefits of each as i don't want to seem like i'm leading the groupor discussion. Please post why you chose each after voting. Let the fireworks begin!
Reply
Reply

AVS Top Picks

post #2 of 43
7/6/09 at 6:18am
Sealed all the way. Let the subwoofers handle the bass properly.
Reply
Reply
post #3 of 43
7/6/09 at 8:49am
There are many 7"-8" woofers that will reach 50-60hz at -3db in a sealed box. This enables you to have a more compact cabinet and the sealed box has less phase shift (easier integration to a sub).
Reply
Reply
post #4 of 43
7/6/09 at 10:43am
I guess output/efficiency will also play a factor. If an 88db sensitity is all that's wanted, sealed no problem. If a 95+db sensitivity is wanted, it'll be tough getting that with an F3 of 60hz.

Either that, or add more woofers, which increases cost.
Reply
Reply
post #5 of 43
7/6/09 at 10:44am
I voted ported, simply because I would like to see 10" pro drivers used instead of another 8" hifi box.
Reply
Reply
post #6 of 43
7/6/09 at 11:51am
"I would like to see 10" pro drivers used instead of another 8" hifi box."

+1

What I really wanted to see was a good 12" driver used.


I voted no preference because I think it's a bit silly to be having a pole about this at this point, which may end up limiting the driver options to what works for a certain cabinet alignment instead of designing the cabinet around the drivers. Any of the options can work in the right circumstance. I would vote against PR just because of the increased costs eating into the budget though.
Reply
Reply
post #7 of 43
7/6/09 at 12:10pm
Quote:


What I really wanted to see was a good 12" driver used.

I was trying to get it but it seems some people are not ready for it
Reply
Reply
post #8 of 43
7/6/09 at 2:04pm
Quote:
Originally Posted by penngray View Post

I was trying to get it but it seems some people are not ready for it

Well maybe for the AVS 2.0 speaker. AVS 1.0 is still in the works. I'm gunnin for a 15" woofer, so maybe AVS 3.0?

BTW, I'm talking versions, like Windows 3.1, not a 2.0 or 3.0 system.
Reply
Reply
post #9 of 43
7/6/09 at 5:59pm
Thread Starter 
Quote:
Originally Posted by Looneybomber View Post

I guess output/efficiency will also play a factor. If an 88db sensitity is all that's wanted, sealed no problem. If a 95+db sensitivity is wanted, it'll be tough getting that with an F3 of 60hz.

Either that, or add more woofers, which increases cost.

Naw, no problem....we can do it.
Reply
Reply
post #10 of 43
7/6/09 at 6:07pm
Thread Starter 
Quote:
Originally Posted by Ricci View Post

"I would like to see 10" pro drivers used instead of another 8" hifi box."

+1

What I really wanted to see was a good 12" driver used.


I voted no preference because I think it's a bit silly to be having a pole about this at this point, which may end up limiting the driver options to what works for a certain cabinet alignment instead of designing the cabinet around the drivers. Any of the options can work in the right circumstance. I would vote against PR just because of the increased costs eating into the budget though.

What's so silly about wanting better integration with a sub? We really haven't designed anything around drivers, just set some very fundamental guidelines, the kind that most designers choose before considering drivers. Seems to me that this type of response, no offense, is simply to validate the posters particular wants instead of what the DIY community is asking for. Of course driver selection will be limited, as they often are in every design. The other option is to pick random drivers and build an enclosure around them and that's not any easier than the approach i've taken. The poll responses would be the same regardless as that' WHAT PEOPLE WANT, which would just force us to go backwards and re-evaluate the driver selection to meet the criteria. I don't understand what's so difficult to understand. What's difficult for me to understand is the arbitrary selection of a single 12" woofer where a pair of so called 'HIFI' 8" driver can perform equally well if not better for less money. And i have absolutely no reservation in saying that a pair of 'HIFI' 10" woofers will exceed a single 12" of equal cost.
Reply
Reply
post #11 of 43
7/6/09 at 6:24pm
Thread Starter 
Woaw! Big surprise with the early results of the polling. Sealed right out of the gate and never looking back. I wonder why there's no proponents of the advantages of a ported alignment when integrating to a subwoofer? This is a real buzzkill for the fans of the Pro 12" driver as even if we ignored the results on the baffle width pole, we'd have to ignore the results of this one as well as there ain't a 12" Pro driver gonna get us to 60hz sealed without a serious compromise in power handling and then why bother. or we could simply ignore the bass extension pole to fit the 12" driver. I'll let this run awhile and give the ported fans a chance to rebutt.
Reply
Reply
post #12 of 43
7/6/09 at 6:30pm
Quote:
Originally Posted by mayhem13 View Post

Woaw! Big surprise with the early results of the polling. Sealed right out of the gate and never looking back. I wonder why there's no proponents of the advantages of a ported alignment when integrating to a subwoofer? This is a real buzzkill for the fans of the Pro 12" driver as even if we ignored the results on the baffle width pole, we'd have to ignore the results of this one as well as there ain't a 12" Pro driver gonna get us to 60hz sealed without a serious compromise in power handling and then why bother. or we could simply ignore the bass extension pole to fit the 12" driver. I'll let this run awhile and give the ported fans a chance to rebutt.

why do you say that?

My sealed TD12S do extremely well in room in 2 cuft enclosures, I think the F3 was 68Hz...in room measurements shows about 60Hz.

I just do not know the drawbacks, I guess.
Reply
Reply
post #13 of 43
7/6/09 at 6:37pm
Quote:


I don't understand what's so difficult to understand. What's difficult for me to understand is the arbitrary selection of a single 12" woofer where a pair of so called 'HIFI' 8" driver can perform equally well if not better for less money. And i have absolutely no reservation in saying that a pair of 'HIFI' 10" woofers will exceed a single 12" of equal cost.

The size of the box needed definitely changes when you want two 8" or two 10" woofers.

But Im all for a MTM ( 10", waveguide or coax, 10" ) ala what John has already built over on aespeakers.com and what Mark Seaton designs).

That would be a kick ass speaker......lets just say the larger the drivers the more Im interested.

Lets find a Coax that matches two TD12M. Im still bias
Reply
Reply
post #14 of 43
7/6/09 at 7:17pm
Quote:
Originally Posted by penngray View Post


Lets find a Coax that matches two TD12M. Im still bias


Penn, that would be a kick a** speaker. Too bad I don't think that any coax's exist that could keep up with a pair of TD12M's. I would definitely be in for that. Sensitivity over 100db/1 watt.
Reply
Reply
post #15 of 43
7/6/09 at 8:23pm
Thread Starter 
Quote:
Originally Posted by penngray View Post

why do you say that?

My sealed TD12S do extremely well in room in 2 cuft enclosures, I think the F3 was 68Hz...in room measurements shows about 60Hz.

I just do not know the drawbacks, I guess.

Yes you do, as it's an S and not an M.
Reply
Reply
post #16 of 43
7/7/09 at 7:10am
Quote:
Originally Posted by mayhem13 View Post

Yes you do, as it's an S and not an M.

You know I have the M too so I will swap out the S for the M but what drawbacks do I have when I put the TD12 drivers in a sealed 2 cuft cabinet? Im curious, I can not be happier with their performance but that is subjective.
Reply
Reply
post #17 of 43
7/7/09 at 8:33am
Depends on the driver, but generally I support ported, so that's what I voted.
Reply
Reply
post #18 of 43
7/7/09 at 4:42pm
Thread Starter 
Quote:
Originally Posted by penngray View Post

You know I have the M too so I will swap out the S for the M but what drawbacks do I have when I put the TD12 drivers in a sealed 2 cuft cabinet? Im curious, I can not be happier with their performance but that is subjective.

The TD12 drivers are great no doubt, but the TD12M wouldn't work for us sealed as the F3 is 120hz in 2cuft. The lowest F3 i can get is 109 at .75cuft fully stuffed. Awesome midwoofer sealed!
Reply
Reply
post #19 of 43
7/7/09 at 5:33pm
Thread Starter 
Well, the way this is shaping up looks like we're going to be sealed.
Reply
Reply
post #20 of 43
7/7/09 at 8:29pm
Thread Starter 
I'll let this poll run till tommorow evening, but i doubt much will change as sealed has such a wide margin as of 35 votes which seems to be near the average response so far. There are some more polls coming before we choose drivers, but for those interested, i'd start making my arguements for 8" woofers.
Reply
Reply
post #21 of 43
7/8/09 at 6:34am
Quote:
Originally Posted by mayhem13 View Post

The TD12 drivers are great no doubt, but the TD12M wouldn't work for us sealed as the F3 is 120hz in 2cuft. The lowest F3 i can get is 109 at .75cuft fully stuffed. Awesome midwoofer sealed!

I did not get those numbers using WinISD

Sealed 2 cuft gives me a F3 of 76Hz, NOTE: with 400W Thats still 115 dB



What did I do wrong?
Reply
Reply
post #22 of 43
7/8/09 at 6:44am
btw, these are the 2-way designs I have been talking about...Sealed, not big....down to 70Hz!!


I thnk that is the TD12M (but maybe the 15")....so I think my measurements above are correct.
Reply
Reply
post #23 of 43
7/8/09 at 7:09am
though it has been around for a while, that is a really nice design.

the shape of the enclosure provides an illusion that the speaker is much smaller than it actually is. it also minimizes the size of the panels, which decreases the possibility of cabinet resonances. it also breaks up internal reflection.

it's kind of rare when form and function actually intersect. i bet that we are going to see a boatload of this type of design in the coming years.
Reply
Reply
post #24 of 43
7/8/09 at 7:38am
Quote:
Originally Posted by penngray View Post

What did I do wrong?

Your scale is off. Each line represents 2db, not 1db, so you're actually showing the F5 since it's peaking around 120db.
Reply
Reply
post #25 of 43
7/8/09 at 7:54am
Quote:
Originally Posted by Looneybomber View Post

Your scale is off. Each line represents 2db, not 1db, so you're actually showing the F5 since it's peaking around 120db.

Is it not a +3db/-3db so you would not just take the peak and subtract 3db. If you were going to use the peak should you not subtract 6db? It looks to me that what penn is doing is correct.
Reply
Reply
post #26 of 43
7/8/09 at 7:57am
Quote:
Originally Posted by penngray View Post

btw, these are the 2-way designs I have been talking about...Sealed, not big....down to 70Hz!!


I thnk that is the TD12M (but maybe the 15")....so I think my measurements above are correct.

I like that design. Would love to see some thing like that using cheaper speakers, but having equal or near equal performance. Either that or a coaxial mid/tweeter in place of the waveguide. Penn do you know what tweeter and waveguide are used in that speaker? Also do you have specs for that design?
Reply
Reply
post #27 of 43
7/8/09 at 7:58am
Quote:
Originally Posted by Looneybomber View Post

Your scale is off. Each line represents 2db, not 1db, so you're actually showing the F5 since it's peaking around 120db.

Ah, I see that the peak for the TD12M is much higher but why does the Fsc say 76? Doesn't that indicate the F3? I never really thought much about it just always used it as my F3 and I left the WinISD on SPL too long, the magnitude graph has the -3 dB line but I never use it.

That is what I was missing thanks!
Reply
Reply
post #28 of 43
7/8/09 at 7:59am
Quote:
Originally Posted by mjg100 View Post

Is it not a +3db/-3db so you would not just take the peak and subtract 3db. If you were going to use the peak should you not subtract 6db? It looks to me that what penn is doing is correct.

Nope, Looney pointed out the flaw or atleast pointed out I was looking at it the wrong way, and the TD12M max is ONLY 6.1 mm (Max Cone excursion at 96Hz with 400Watts!) vs the TD12S 14 mm, I forgot that was the MAIN reason I picked the TD12S

Whats that physics law about high sensitivity, low frequency, Xmax, etc? case in point here

TD12Ms will be ported
Reply
Reply
post #29 of 43
7/8/09 at 7:59am
i think the -3db point is measured relative to the "average" spl across the usable frequency range, not from the highest peak.
Reply
Reply
post #30 of 43
7/8/09 at 8:35am
I was under the impression that F3 (or any F#) shows the point 3db down from reference; reference being the peak. If it was LP at 70hz, the F3 point would drop quite a bit from where it's currently at...Though output too would drop.
Reply
Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: DIY Speakers and Subs

AVS Top Picks

AVS › AVS Forum › Audio › DIY Speakers and Subs › DIY HT Design...Ported or Sealed?