myn's Tuba HT Review (LLT vs THT) - Page 4 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #91 of 403 Old 11-09-2009, 05:59 AM
AVS Special Member
 
PassingInterest's Avatar
 
Join Date: Nov 2006
Location: Dallas, Tx
Posts: 1,730
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 37 Post(s)
Liked: 71
Sorry if this was covered already, but for my shopping list I need to know if pinning with a nail gun during construction is acceptable in place of screws?
Both need the PL glue, of course.

"Still, a man hears what he wants to hear and disregards the rest." --Paul Simon The Boxer
PassingInterest is offline  
Sponsored Links
Advertisement
 
post #92 of 403 Old 11-09-2009, 06:26 AM
AVS Special Member
 
dbldare's Avatar
 
Join Date: Jan 2001
Location: Broomfield, CO USA
Posts: 2,518
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 15
The instructions state that you can use 1 and 1-5/8 inch ribbed shank paneling nails using a nail punch to set heads below surface or brad nailer using 1 and 1.25 inch brads. They are just to hold it while adhesive sets.


Dbl

Let's all go to the lobby
....Let's all go to the lobby
........Let's all go to the lobby
............To get ourselves a treat!
dbldare is offline  
post #93 of 403 Old 11-09-2009, 06:35 AM
AVS Addicted Member
 
penngray's Avatar
 
Join Date: Feb 2006
Location: Florida
Posts: 26,779
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 30
Quote:
Originally Posted by Garric33 View Post

How would a monster (like Ricci's LLT) perform in the sub-20 Hz area compared to your THT ? I am trying to see what some pros/cons of LLT/THT would be. Does an LLT at a fairly common low tuning of 11 Hz perform better in it's tuning area than a THT tuned to 22 Hz ?

Again, for the purposes of what we are talking about, we can assume reasonable gear choices for each of LLT/THT. I'd like to get an idea of whether the LLT has a reason for existing anymore versus a THT.

Ricci is testing the DTS-10 so he should post his results at some point.

It is not "open-minded" to reject knowledge - Bob Lee
penngray is offline  
post #94 of 403 Old 11-09-2009, 06:45 AM
AVS Special Member
 
brandonnash's Avatar
 
Join Date: Jul 2003
Location: murfreesboro, tn
Posts: 3,942
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 25
Quote:
Originally Posted by penngray View Post

Ricci is testing the DTS-10 so he should post his results at some point.

And I believe he will get his kit this week. He has all kinds of good measuring equipment that I don't have. Getting the drivers for mine today and I will post some initial listening tests but no measurements.
brandonnash is offline  
post #95 of 403 Old 11-09-2009, 06:50 AM - Thread Starter
AVS Special Member
 
mynym's Avatar
 
Join Date: Nov 2004
Location: Columbus, OH
Posts: 1,188
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 14 Post(s)
Liked: 15
Quote:
Originally Posted by PassingInterest View Post

Sorry if this was covered already, but for my shopping list I need to know if pinning with a nail gun during construction is acceptable in place of screws?
Both need the PL glue, of course.

You can definitely use a nail gun in place of screws. Many choose this method.

Because some of my Arauco plywood wasn't perfect (warped a bit) I choose to use screws using this method:

I predrill, primarily because I have a much easier time getting the panels lined up perfectly square before I put the PL on.

1) Line up the next panel
2) clamp
3) predrill screw holes (I go about 3/8" into the piece I'm attaching)
4) unclamp
5) apply PL
6) Clamp
7) screw, making sure to hit the hole on the panel being attached
take off clamps and admire perfect alignment of panel.
mynym is offline  
post #96 of 403 Old 11-09-2009, 07:36 AM
AVS Special Member
 
stgdz's Avatar
 
Join Date: May 2002
Location: MNsnowta in april :(
Posts: 2,188
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
Quote:
Originally Posted by maxmercy View Post

My THT has never seen more than 80 Watts, and that's because I boost the sub-20Hz region due to my room. I don't get much room gain. Above 20Hz, my THT usually never sees more than 10 Watts.

The dual 18's will probably outdo the THT below 15Hz, only due to the displacement advantage they have. The THT is only horn loaded to 22Hz, and the response drops from there until it matches a sealed 15". Above 20Hz, you have a competition to post about....

JSS

So you are saying something like a 106w gainclone would work pretty well with the THT?
stgdz is offline  
post #97 of 403 Old 11-09-2009, 10:21 AM
AVS Special Member
 
dbldare's Avatar
 
Join Date: Jan 2001
Location: Broomfield, CO USA
Posts: 2,518
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 15
Random question - slightly OT.

I have a set of old Cerwin Vega D9's (15"). I don't know the specs on the woofer unfortunately. I don't mind buying the Dayton, but if one of these will work I can utilize it. In fact, I have two so hummmmm.......?????


dbl

Let's all go to the lobby
....Let's all go to the lobby
........Let's all go to the lobby
............To get ourselves a treat!
dbldare is offline  
post #98 of 403 Old 11-09-2009, 10:24 AM
Bass Enabler
 
Scott Simonian's Avatar
 
Join Date: Oct 2001
Location: Clovis, CA
Posts: 14,309
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 859 Post(s)
Liked: 1030
Have you got the T/S specs for those? I'd wager that they would not work but who knows.

My Dual 18" LLT subs 120dB down to 10hz

 

Plan9Reloaded Co-host

Listen to the Plan9Reloaded Gaming and Technology Podcast (may contain NSFW language)

https://soundcloud.com/plan9reloaded/sets/podcast - direct pod link

http://plan9reloaded.com/site/ - main website

Scott Simonian is online now  
post #99 of 403 Old 11-09-2009, 10:26 AM
AVS Special Member
 
mjaudio's Avatar
 
Join Date: Nov 2002
Posts: 2,476
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked: 36
So how would this compare to the Danley DTS-10 kit performance wise?

Would these work the same laying on it's side like a coffee table version? Anyone able to camouflage these well for a living room setting?

"Half the world is looking for Jesus, and the other half is looking for more bass..."
mjaudio is offline  
post #100 of 403 Old 11-09-2009, 10:26 AM
AVS Special Member
 
dbldare's Avatar
 
Join Date: Jan 2001
Location: Broomfield, CO USA
Posts: 2,518
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 15
No specs, but I'll see what I can find.

Old school! Represent!


dbl

Let's all go to the lobby
....Let's all go to the lobby
........Let's all go to the lobby
............To get ourselves a treat!
dbldare is offline  
post #101 of 403 Old 11-09-2009, 10:51 AM - Thread Starter
AVS Special Member
 
mynym's Avatar
 
Join Date: Nov 2004
Location: Columbus, OH
Posts: 1,188
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 14 Post(s)
Liked: 15
Quote:
Originally Posted by mjaudio View Post

Would these work the same laying on it's side like a coffee table version? Anyone able to camouflage these well for a living room setting?

It's funny you mention that. When I was installing the access panel it was on it's side and it strongly resembled a coffee table. Good height and size. I went so far as to measure it to see if it would fit into my existing L shaped couch arrangement. It would fit but the boundary loading would be an issue as it's in the middle of the room.


Some people have done some very creative things with the THT's little brother, the TableTuba:



mynym is offline  
post #102 of 403 Old 11-09-2009, 11:11 AM
AVS Special Member
 
Ricci's Avatar
 
Join Date: Mar 2007
Location: Louisville KY
Posts: 5,131
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 42 Post(s)
Liked: 242
Quote:
Originally Posted by Garric33 View Post

How would a monster (like Ricci's LLT) perform in the sub-20 Hz area compared to your THT ? I am trying to see what some pros/cons of LLT/THT would be. Does an LLT at a fairly common low tuning of 11 Hz perform better in it's tuning area than a THT tuned to 22 Hz ?


I don't see anyway that a 22-25hz low corner horn enclosure can compete below it's driver horn loading even if it is acting like a sealed sub at that point as in a FLH. Even a horn enclosure can't make up for that kind of displacement disadvantage. Losing 10-15db of raw displacement is hard to overcome. I've still yet to hear anything that does 25-10hz like the ported enclosure I have. I'm not saying that I won't at somepoint, but expecting something operated below it's intended passband to do it is dubious. BTW I'm not knocking the THT, I've never heard one and I have no doubt that it would easily best an EBS type enclosure when it is operated 20-100hz. Also I'm only talking about maximum output levels and nothing to do with percieved SQ.





Quote:
Originally Posted by maxmercy View Post

Huge LLTs will have an advantage in the subsonic range, it's just physics, no replacement for displacement, but that displacement only takes place at larger power levels....

What a lot of people fail to realize is that the majority of movie bass is above 20Hz, right in the THT's and TH50's wheelhouse...with few exceptions, all the bass in music takes place above 30Hz....

The slam and kick you feel is way higher than you think, above 50Hz....

Here's a spectrum of me hitting the snare, rack toms, floor tom and kick drum on my drum kit. I use Ebony pinstripe heads, in other words tuned low compared to most kits. You can see that my floor tom has a pitch bend in its lower register, and that the kick has most of it's energy at 50Hz. It's fundamental resonates at 35Hz....

JSS

I basically agree with this. This is why my review of the TH50 was the way it was. Even if it was filtered below 20hz, the meat of most recordings is above 20hz and it has King Kong like output there.

Stealing a page and posting up some drum spectrum analysis? It's very cool to see someone else do this. What microphone did you use? I used a ECM8000 measurement mic which is pretty flat between 20-10khz at least. I'm thinking about doing this again and trying to get things a bit more accurate. Like by doing it outside.



Quote:
Originally Posted by craigsub View Post

EDIT - The ESB sub I modeled was using the B&C 21 inch driver in a 20 cubic foot enclosure and tuned to 15 Hz. The amp was a 1500 watt amplifier. That would be one heck of a subwoofer.

Heh. I see that you listened to my post in your other thread. BTW I wouldn't tune that driver much lower than about 20hz and with a much smaller enclosure with a huge slot vent (10cu ft and 65-70sq " of port, add 2000w, 16hz HPF, stir). You don't want a peaking response at tune and, it's better to take advantage of the massive power handling and efficiency by using more power safely in a smaller higher tuned enclosure than scrabbling for every last bit of extension. THAT would be a hell of a SW.

BTW. WinISD cannot model horn enclosures. For that you want HornResponse or Akabak. Hornresponse is free and it's not too difficult to figure out.






Quote:
Originally Posted by penngray View Post

Ricci is testing the DTS-10 so he should post his results at some point.

Yep. I know what I'm hoping it will do. I think I have a realistic expectation. We'll see.
Ricci is offline  
post #103 of 403 Old 11-09-2009, 02:26 PM
AVS Special Member
 
J_Palmer_Cass's Avatar
 
Join Date: May 2005
Posts: 6,475
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 277 Post(s)
Liked: 103
Quote:
Originally Posted by mynym View Post


121db @ 22hz with only 10.8 volts or 29 watts! and Couch Moving!
http://www.youtube.com/watch?v=--7My1qU1Eg





This is the spectrogram of that 22 Hz tone. Seem to be a lot of harmonics in there.


J_Palmer_Cass is offline  
post #104 of 403 Old 11-09-2009, 02:42 PM
AVS Addicted Member
 
Bill Fitzmaurice's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 10,209
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 1684
Quote:
Originally Posted by Ricci View Post

I don't see anyway that a 22-25hz low corner horn enclosure can compete below it's driver horn loading even if it is acting like a sealed sub at that point as in a FLH. Even a horn enclosure can't make up for that kind of displacement disadvantage.

It's actually not the case. I modeled the THT and an LLT with the same driver. Both were 18 cubic foot boxes, the LLT tuned to 12Hz. Except at the 12Hz tuning frequency the THT had considerably less excursion than the LLT for the same applied power. The LLT did have higher sensitivity below 20 Hz, but when it came down to maximum SPL the THT was the winner. And of course the THT will have much lower distortion than the direct radiator.

Bill Fitzmaurice Loudspeaker Design

The Laws of Physics aren't swayed by opinion.
Bill Fitzmaurice is offline  
post #105 of 403 Old 11-09-2009, 02:42 PM
AVS Special Member
 
dbldare's Avatar
 
Join Date: Jan 2001
Location: Broomfield, CO USA
Posts: 2,518
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 15
Did you get that audio (graph) off of his you tube video?


dbl

Let's all go to the lobby
....Let's all go to the lobby
........Let's all go to the lobby
............To get ourselves a treat!
dbldare is offline  
post #106 of 403 Old 11-09-2009, 02:43 PM
AVS Special Member
 
dbldare's Avatar
 
Join Date: Jan 2001
Location: Broomfield, CO USA
Posts: 2,518
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 15
Welcome Bill!

dbl

Let's all go to the lobby
....Let's all go to the lobby
........Let's all go to the lobby
............To get ourselves a treat!
dbldare is offline  
post #107 of 403 Old 11-09-2009, 02:45 PM
Advanced Member
 
Rightbrained's Avatar
 
Join Date: Jun 2008
Location: LA , Lower Alabama that is
Posts: 818
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Welcome aboard Bill. Nice to see you here.

If at first you dont succeed , get a bigger hammer !
Rightbrained is offline  
post #108 of 403 Old 11-09-2009, 03:11 PM
Bass Enabler
 
Scott Simonian's Avatar
 
Join Date: Oct 2001
Location: Clovis, CA
Posts: 14,309
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 859 Post(s)
Liked: 1030
Quote:
Originally Posted by J_Palmer_Cass View Post

This is the spectrogram of that 22 Hz tone. Seem to be a lot of harmonics in there.


I used to use a sine wave generator that I liked for a few years. When I got spectralab I tested it out for the hell of it and found that it was plauged with harmonic distorition. Maybe that is the case here. Although I wouldn't hold a youtube video the the highest regards with fidelity either...


Quote:
Originally Posted by Bill Fitzmaurice View Post

It's actually not the case. I modeled the THT and an LLT with the same driver. Both were 18 cubic foot boxes, the LLT tuned to 12Hz. Except at the 12Hz tuning frequency the THT had considerably less excursion than the LLT for the same applied power. The LLT did have higher sensitivity below 20 Hz, but when it came down to maximum SPL the THT was the winner. And of course the THT will have much lower distortion than the direct radiator.

Welcome, Bill! I like the sound of these THT's. Might have to build a few.

My Dual 18" LLT subs 120dB down to 10hz

 

Plan9Reloaded Co-host

Listen to the Plan9Reloaded Gaming and Technology Podcast (may contain NSFW language)

https://soundcloud.com/plan9reloaded/sets/podcast - direct pod link

http://plan9reloaded.com/site/ - main website

Scott Simonian is online now  
post #109 of 403 Old 11-09-2009, 03:21 PM
AVS Special Member
 
Ricci's Avatar
 
Join Date: Mar 2007
Location: Louisville KY
Posts: 5,131
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 42 Post(s)
Liked: 242
Quote:
Originally Posted by Bill Fitzmaurice View Post

It's actually not the case. I modeled the THT and an LLT with the same driver. Both were 18 cubic foot boxes, the LLT tuned to 12Hz. Except at the 12Hz tuning frequency the THT had considerably less excursion than the LLT for the same applied power. The LLT did have higher sensitivity below 20 Hz, but when it came down to maximum SPL the THT was the winner. And of course the THT will have much lower distortion than the direct radiator.

Hello Bill and welcome to the forum.

While I admit that you have a great deal of audio knowledge and obviously more familiarity with horns and the THT itself, I will still have to humbly disagree. I was only referring to the output below which the THT would cease to be functioning as a horn. The THT would be rolling off at 12 db octave below the cut-off which is nearly an octave above the 12hz tune you mentioned.The port should be decreasing excursion quite a bit below 20hz if tuned to 12hz. I don't see how what amounts to basically a sealed enclosure below the horn loading could have much more maximum output than a much larger ported one, until below tuning? The ported should have more efficiency and maximum output there. Subwoofers are nearly always displacement limited in that range so looking at the applied power is not as important as higher up in the range, where the THT whomps the ported sub easily.

BTW if you'll entertain a question? How much theoretical maximum output is gained by a horn loading (FLH in this case) over the drivers simple sealed excursion limited output? 10db?
Ricci is offline  
post #110 of 403 Old 11-09-2009, 03:38 PM
AVS Special Member
 
Mark Seaton's Avatar
 
Join Date: Jul 2000
Location: Chicago, IL, USA
Posts: 6,085
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 105 Post(s)
Liked: 321
Quote:
Originally Posted by Ricci View Post

Hello Bill and welcome to the forum.

While I admit that you have a great deal of audio knowledge and obviously more familiarity with horns and the THT itself, I will still have to humbly disagree. I was only referring to the output below which the THT would cease to be functioning as a horn. The THT would be rolling off at 12 db octave below the cut-off which is nearly an octave above the 12hz tune you mentioned.The port should be decreasing excursion quite a bit below 20hz if tuned to 12hz. I don't see how what amounts to basically a sealed enclosure below the horn loading could have much more maximum output than a much larger ported one, until below tuning? The ported should have more efficiency and maximum output there. Subwoofers are nearly always displacement limited in that range so looking at the applied power is not as important as higher up in the range, where the THT whomps the ported sub easily.

BTW if you'll entertain a question? How much theoretical maximum output is gained by a horn loading (FLH in this case) over the drivers simple sealed excursion limited output? 10db?

Hi Ricci,

Your question is a very good point of evaluation and comparison of what is going on with loading in different designs. To clarify, output vs. excursion from a given size cone is a good comparison to make and a sanity check as to what you are or are not gaining with a given approach.

There are other considerations as well, where gains in the upper octaves typically greatly reduce distortions at those frequencies, but also amplify any distortion products created at lower frequencies (ie below the corner). I'll be the first to note that this doesn't make the output below the corner useless, as the audibility of the distortion and other factors come into play, especially the linearity of the driver. What it does do is make direct comparisons nearly impossible, as you will always have ying/yang benefits/detriments which will also be dependent on the application and limitations of a given system.

Mark Seaton
Seaton Sound, Inc.
"Make no little plans; they have no magic to stir men's blood..." Daniel H. Burnham
Mark Seaton is offline  
post #111 of 403 Old 11-09-2009, 03:49 PM
AVS Addicted Member
 
MKtheater's Avatar
 
Join Date: Jul 2006
Location: New Hartford, NY
Posts: 14,782
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 376 Post(s)
Liked: 521
Hey guys I tested 2 18 inch folded horns against my 8 sealed 18 inch subs and according to the spl meter during the pulse scene(15-19 Hz) they were equal. The difference was how they sound, much different. The folded horns had mid bass to die for and the sealed subs had pressurization, hair standing up, visceral effects, and much more room shaking. According to just the spl meter they should do the same. I would take folded horns over anything from Hz and up but not below. The Danley DTS-10 gets me excited because if it can do both then we are talking bass nirvana.

AVR-Yamaha A830
amps-5 Adcom 555 in 850 watt monoblock mode
sub amp-Sanway FP14K
LCR-Dual stacked BFM DR-250's
Surrounds- Dual stacked BFM W10's
subs-12 SI 18's ported 6hz.
MKtheater is offline  
post #112 of 403 Old 11-09-2009, 03:58 PM - Thread Starter
AVS Special Member
 
mynym's Avatar
 
Join Date: Nov 2004
Location: Columbus, OH
Posts: 1,188
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 14 Post(s)
Liked: 15
Quote:
Originally Posted by J_Palmer_Cass View Post

This is the spectrogram of that 22 Hz tone. Seem to be a lot of harmonics in there.




I don't trust my little Canon Elph to pick up freqs at that low frequency nevermind at that SPL level. Compound that with YouYube's compression.

As promised, I will be taking distortion measurements very soon though.
mynym is offline  
post #113 of 403 Old 11-09-2009, 04:03 PM
AVS Addicted Member
 
Bill Fitzmaurice's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 10,209
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 1684
Quote:
Originally Posted by Ricci View Post

The port should be decreasing excursion quite a bit below 20hz if tuned to 12hz. I don't see how what amounts to basically a sealed enclosure below the horn loading could have much more maximum output than a much larger ported one, until below tuning?

This should help. The darker trace is the excursion of a Tempest loaded 18 cu ft THT with 28 volts input; the lighter trace is the same driver in a 12 Hz 18 cu ft LLT with only 20 volts input. Yes, the LLT has higher sensitivity below 20 Hz, but that's offset by the higher displacement limited power capability of the THT, so it's a virtual wash.

Quote:


BTW if you'll entertain a question? How much theoretical maximum output is gained by a horn loading (FLH in this case) over the drivers simple sealed excursion limited output? 10db?

This shows the THT and the THT sealed chamber without the horn.


THT has about a 22Hz corner frequency, intentionally to account for typical cabin gain. What I notice about LLTs is that they tend to run flat or even with a bump at Fb, and that combined with cabin gain can make them a bit too much way down low. You can compensate by pulling down EQ of course, and that's a good thing to conserve power and excursion, but my feeling is that a smaller box with a bit higher tuning is an alternative that should be considered.

Bill Fitzmaurice Loudspeaker Design

The Laws of Physics aren't swayed by opinion.
Bill Fitzmaurice is offline  
post #114 of 403 Old 11-09-2009, 05:04 PM
 
mjg100's Avatar
 
Join Date: Dec 2006
Posts: 9,112
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Quote:
Originally Posted by Ricci View Post

Hello Bill and welcome to the forum.

While I admit that you have a great deal of audio knowledge and obviously more familiarity with horns and the THT itself, I will still have to humbly disagree. I was only referring to the output below which the THT would cease to be functioning as a horn. The THT would be rolling off at 12 db octave below the cut-off which is nearly an octave above the 12hz tune you mentioned.The port should be decreasing excursion quite a bit below 20hz if tuned to 12hz. I don't see how what amounts to basically a sealed enclosure below the horn loading could have much more maximum output than a much larger ported one, until below tuning? The ported should have more efficiency and maximum output there. Subwoofers are nearly always displacement limited in that range so looking at the applied power is not as important as higher up in the range, where the THT whomps the ported sub easily.

BTW if you'll entertain a question? How much theoretical maximum output is gained by a horn loading (FLH in this case) over the drivers simple sealed excursion limited output? 10db?

Bill stated both subs as 18 CF.
mjg100 is offline  
post #115 of 403 Old 11-09-2009, 05:17 PM
AVS Special Member
 
maxmercy's Avatar
 
Join Date: Nov 2008
Posts: 2,375
Mentioned: 2 Post(s)
Tagged: 1 Thread(s)
Quoted: 43 Post(s)
Liked: 147
So you are saying something like a 106w gainclone would work pretty well with the THT?

It's always nice to have at least 3dB of headroom available, but I'd say unless you listen at insane levels, a real 106W amp should do you fine...

I use the Oaudio 500W amp, and I have never put more than 15V into my THT, and that was only when testing for distortion vs spl (results in previous post).

Although the driver I am using has 14mm of Xmax, it is my experience that using only half of the rated Xmax results in tolerable distortion levels.

Mark Seaton - you have struck upon the achilles heel of my THT...and the reason why I must highpass so aggressively below 15Hz in my THT. The harmonics of frequencies below horn cutoff get amplified, and are more easily audible...that being said, when properly high-passed, it rocks. I also boost 15-20Hz some to get a flatter response, but I am still under 5% THD when playing sinewaves at -3.0dBFS....the freq response of the Oaudio amp I use is at www.oaudio.com

I use the 16Hz subsonic setting, which boosts some and has a highpass, which I have to augment with my Reckhorn B-1's HP to keep distortion down below 15Hz...

Myn - I agree with you about the distortion in the SpecLab graph...hopefully you'll get to do your distortion tests soon...

Ricci - Had no idea you had done the same thing with your drumkit...I used a Galaxy CM140 and SpecLab, no calfile onboard to correct for the falling response of the Galaxy meter....

JSS
maxmercy is online now  
post #116 of 403 Old 11-09-2009, 07:20 PM
AVS Special Member
 
Ricci's Avatar
 
Join Date: Mar 2007
Location: Louisville KY
Posts: 5,131
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 42 Post(s)
Liked: 242
Quote:
Originally Posted by Bill Fitzmaurice View Post

This should help. The darker trace is the excursion of a Tempest loaded 18 cu ft THT with 28 volts input; the lighter trace is the same driver in a 12 Hz 18 cu ft LLT with only 20 volts input. Yes, the LLT has higher sensitivity below 20 Hz, but that's offset by the higher displacement limited power capability of the THT, so it's a virtual wash.

This shows the THT and the THT sealed chamber without the horn.


I understand that the THT will take more input power for the most part below 22hz before over excursion sets in, but this is offset by the major disadvantage in efficiency there unless I'm mistaken. The excursion at 10hz is only 8mm but it is greater or equal everywhere between 10-25hz. Increasing the 28v level will quickly result in over-excursion and only a modest increase in output before the driver gets into trouble. At 20v input the ported cab would be doing close to 105db from 11hz on up. The THT appears to be about 15db down from the 25hz level at 17 or 18hz already with it very rapidly losing output from there and even though it's 10db more efficient at 20hz than the sealed enclosure, the ported cab would be itself about 6 or 7db more efficient than the sealed enclosure and would greatly increase it's lead down to 10hz while the THT loses efficiency as shown. It still seems like the ported ebs in this scenario will have an advantage at 18hz and below to me.

This is apples to oranges anyway. If you level the playing field and have the cabinet cut-offs be nearly the same at 22hz , the horn will win nearly everywhere.

Again I'm not knocking your work Bill. Also the original question wasn't comparing enclosures using the same driver, as many times the drivers used in a big EBS aren't really the best choice for a horn enclosure and vice versa.



Quote:
Originally Posted by mjg100 View Post

Bill stated both subs as 18 CF.

Yes he did Mike. However there is not an 18cu ft sealed chamber inside of the THT. It is a much smaller volume. 18cu ft would be the total THT size. That was why I mentioned a small sealed chamber. This is one reason why I like this style of horn is because even though it will have falling response below the cut-off the small sealed chamber does help to protect the driver from over excursion damage somewhat.
Ricci is offline  
post #117 of 403 Old 11-10-2009, 05:05 AM
Advanced Member
 
2100's Avatar
 
Join Date: Mar 2008
Location: Singapore
Posts: 729
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by J_Palmer_Cass View Post

This is the spectrogram of that 22 Hz tone. Seem to be a lot of harmonics in there.[/IMG]

Bro, I see you talking about some pretty deep and really lengthy stuff about bass in some other threads.... I think you should know the answer yourself man...
2100 is offline  
post #118 of 403 Old 11-10-2009, 06:13 AM
AVS Special Member
 
J_Palmer_Cass's Avatar
 
Join Date: May 2005
Posts: 6,475
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 277 Post(s)
Liked: 103
Quote:
Originally Posted by 2100 View Post

Bro, I see you talking about some pretty deep and really lengthy stuff about bass in some other threads.... I think you should know the answer yourself man...


Why? There are multiple errors that could have occured, and I am not going to start guessing with the limited information that I have to work with.

I never have figured out why people test with high level single tone sine waves anyhow. That would be dB FS and dB SPL!


This is a waterfall of a high level sweep that Ilkka did on a Tumult MK-1. Distortion is easy to see, but it does not look like the harmonics for this subwoofer.


J_Palmer_Cass is offline  
post #119 of 403 Old 11-10-2009, 02:11 PM
AVS Special Member
 
PassingInterest's Avatar
 
Join Date: Nov 2006
Location: Dallas, Tx
Posts: 1,730
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 37 Post(s)
Liked: 71
Mynym, that was a good catch on the DVC gasket air leaks (in your construction thread).
The first thing I intend to do when mine arrives is seal the gasket leaks.

"Still, a man hears what he wants to hear and disregards the rest." --Paul Simon The Boxer
PassingInterest is offline  
post #120 of 403 Old 11-10-2009, 04:59 PM
Senior Member
 
superedge88's Avatar
 
Join Date: Aug 2009
Posts: 418
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked: 16
I just ordered my Dayton woofer last night, gonna fix the leaks with latex caulk right away! Can't wait to start my THT this weekend!
superedge88 is offline  
Reply DIY Speakers and Subs



Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off